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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to aquatic animal culturing, including culturing of fish, crustaceans, plants, corals, and other aquatics, and aquariums and more particularly to a system for compartmentalizing such systems while permitting a flow of water between those compartments and to maintain the separation of any aquatic specimens within those compartments while also providing a superior aquatic environment, such as for display aesthetics, water quality within the compartments and the aquatic life clean and safe, while permitting aquatic waste removal and waste processing/collection. This application is based upon our U.S. Provisional Application No. 61/574,064, filed on 27 Jul. 2011, which is incorporated herein by reference in its entirety.
[0003] 2. Background of the Invention
[0004] Typical aquariums will often have a variety of aquatic specimens within a typically elongated tank. Those aquatic specimens may get along with each other and they may not. Those elongated tanks often have to be cleaned out relatively frequently because of the contamination from the specimens and whatever else may collect within the water. Many types of aquatic specimens do not get along well with one another and will attack and/or eat their tank mates if and when they are given the chance.
[0005] It is an object of the present invention to provide an aquarium which may be subdivided into varying sized compartments to segregate any particular aquatic specimens or species of specimens from any other specimens.
[0006] It is a further object of the present invention to provide an aquarium which is intended to have an extended life cycle without requiring the need for frequent cleansing of the tanks or their individual compartments.
[0007] It is a still further object of the present invention to provide an aquarium for multiple specimens, one or more of whom require cleaner water than the other specimens or the downstream currents of the other specimens to allow and promote the exchange of chemical stimulants between the specimens.
[0008] It is a further object of the present invention to provide a “bottom current” or a similar means to sweep sedimentary debris from successive compartments and into a filtration and processing/collection system to provide a cleaner and more healthy environment, while permitting the further use of such aquatic/fish debris.
[0009] It is yet a further object of the present invention to provide a “low current” living and display environment for aquatic specimens that prefer such conditions within a portion of the compartment, and also provide “cleansing currents” that infiltrate filtered water into each respective compartment and remove waste and debris from such compartment and process it in the filtration part of the aquatic system.
[0010] It is another object of the present invention to provide a means to contain large specimens within respective compartments while allowing smaller aquatic specimens passage to one or more of the other compartments and by the graduation in size of respective compartment dividers creating a method to sort the specimens by size, thereby minimizing interaction and chances for predation between larger and smaller specimens including parent and offspring.
[0011] It is a further object of the present invention to provide an aquarium for multiple aquatic specimens, one or more of whom require cleaner water, or other condition and state, including in the introduction and transfer of nutrients or chemicals and stimulants from other specimens and anthropogenic means than the others.
[0012] It is another object of the present invention to provide compartments which permit the individual respective use of each as filtration systems including the use of flora and aquatic specimens to provide additional filtration capacity, prior to a subsequent compartments, with an anesthetic display.
[0013] It is yet a further object of the present invention to create a filtration system in the rear portion of the elongated tank that processes waste water and thereby cleansing, treating and aerating the water in the aquatic system and also being the means for creating the flow and current of the system. This filtration system draws in the water from the last compartment at one end of the elongated tank and ejects the cleansed and treated water into a first compartment at the other end of the process or the elongated tank. A variant of this system could draw water from a center section or compartment and use one or more respective end sections or compartments for discharging cleansed or treated water individually or in combination.
BRIEF SUMMARY OF THE INVENTION
[0014] The present invention comprises an aquatic system for the compartmentalized storage/display and maintenance of a plurality of aquatic specimens, such as for example fish or other live aquatic specimens. The aquatic system in a first preferred embodiment thereof comprises an elongated tank having a first or upstream end wall and a second or downstream end wall, a bottom or floor, and a front wall and a rear wall. The elongated tank in this particular embodiment is divided into a plurality of compartments by a plurality of spaced apart divider panels. This embodiment may include a filtration system attached to the rear of the tank, comprised of a new rear tank wall, sidewalls, a bottom and various divider panels utilized in the filtration/treatment process with this filtration system also being the means to establish the flow or current in the main compartmentalized aquatic storage section of the elongated tank.
[0015] The divider panels are supported transversely across the longitudinal length of the tank by engagement tabs discussed hereinbelow. Each divider panel has an elongated gap between its lowermost edge and the bottom or floor of the tank. Each divider panel also has an elongated gap between its respective side edges and the adjacent sidewalls of the tank. The divider panels may be spaced apart a uniform distance or a non-uniform distance from one another, as necessary, for the segregated containment of different sizes of different aquatic species within their own individual compartment(s).
[0016] The divider panels themselves may be transparent, opaque, or partially or fully opaque, or even colored, as desired. Each divider panel may also have perforations therein, to further allow transfer between compartments and permit downstream fluid flow between successively adjacent compartments. The perforations in any particular panel as well as the gaps along their side edges and the side walls and the gap between the lower edge of the divider panels and the bottom or floor of the tank would be of course smaller than any particular species of aquatic life which was being retained within that particular compartment, in order to maintain their separation from one another. Such perforations and/or gap between the lower edges of the divider panels and the floor may be, for example, about ⅛ to ½ of an inch depending upon the size and species of aquatic life contained there within. Commercially sized aquatic systems for the farming offish and/or other species of aquatic life may necessitate larger or smaller gaps to prevent their intermixing. The gaps will allow the separation of specimens and or provide specific flow patterns within one or more individual compartment.
[0017] The purpose of the openings and/or bottom gaps is to permit a directionally aimed or a laminar flow of water to pass between the bottom of adjacent compartments and thus carry waste products such as fecal matter and aquatic debris from an upstream end of the flow of water to a downstream end of the flow of water. The aquatic life in each compartment contributes to the debris and fecal matter which settles gently to the bottom of each compartment and is swept downstream through the bottom and other gaps.
[0018] The flow of water for this aquatic system begins at the upstream end of the tank and passes through each individual compartment via the gaps and openings. The flow of water through the compartments ends at the downstream end. In this embodiment, it enters a filtration system through a plurality of holes/slots and the water exits the filtration system and back into the compartmentalized portion of the tank through one or more holes or slots in the upstream end of the tank. The filtration system itself, may contain various compartments that process the water and waste and provide treatment through mechanical, biological, chemical and or photonics. These various processing compartments can include sedimentation traps, sponges, bio media, drip tubes, mechanical pumps and aerators, agitators, protein skimmers, ultraviolet sterilizers and other filtration specific devices that aid in the process and treatment of the water in the aquatic system.
[0019] A further embodiment of the present invention comprises the bottom or floor of the aquatic system having a stepped configuration as viewed from the side. In such a stepped embodiment, the downstream divider panels would be of increasingly varying dimension to accommodate the difference in height due to the stepped bottom their adjacent. A gap or opening would still be necessary between the lower edge of each divider panel and its adjacent floor portion of its respective compartment, to accommodate and permit a smooth flow of water and the step passage of aquatic debris and fecal matter downstream.
[0020] In yet a further embodiment of the present invention, the bottom or floor of the tank is of sloped configuration as viewed from the side. In such a sloped-floor embodiment, the downstream divider panels are of increasingly greater height to accommodate the greater depth of that particular compartment. The gap or opening arrangement would still be required between the bottom edge of the divider panel and the surface of the floor there adjacent.
[0021] The aquatic system in yet a further embodiment thereof may be comprised of a non-linear tank, as for example, one of circular configuration as may be viewed in a plan view thereof. Such a non-linear tank may have an outer wall and a correspondingly configured innermost wall with the innermost wall attached to the inside of the outermost wall by a rigid panel therebetween. Such a rigid panel would function as both the beginning or upstream end of the water flow on one side thereof and as the end or downstream portion of the water flow on the other side of that rigid panel. Each respective side of that rigid panel would have a filtered water source or a filtered water extractor arranged respectively thereat. The divider panels in such a non-linear tank would divide the volume of that tank into generally “pie” shaped compartments. Each divider panel would of course have a gap or openings between its side edges and the inner wall and the inside edge of the outer wall as well as the lower edge of that panel and the floor or bottom of the tank.
[0022] A further aspect of the present invention is the method of maintaining similar or different aquatic specimens or fish and sequentially altered water within the elongated or the non-linear tank. The water in each successive chamber downstream may contain elements from the previous chambers due to the nature of the flow and the water may thus be slightly altered from its upstream neighbor. Upstream treatments, both natural and anthropogenic can alter the water to affect specific responses, such as is considered in aquaculture. The nature of the flow allows the upstream compartments to have “cleaner” water than each successive compartment.
[0023] A still further aspect of the present invention comprises the use of a retrofit panel support arrangement for use within an existing tank or core, as a kit, to enable the support of one or more divider panels therewithin, so is to subdivide a tank by those panels, while maintaining a changeable space (compartment) between those panels and the flow of water along the floor of the tank under and around the side of the tank's walls.
[0024] The invention thus comprises a system for the sustained support and segregation of various species of aquatic life in a fluid containment tank and may include a combined filtration system that also generates the current in the tank. The tank has an upstream end and a downstream end, the system comprising: an arrangement of a top cover and enclosure walls and a lowermost floor; at least one divider panel supported between the exterior walls or by means of support members to divide the tank into at least two compartments, the divider panel having a pair of side edge portion and a lowermost edge portion; a gap between the lowermost edge portion of the at least one divider panel and the lowermost floor to permit a flow of water therebetween from the upstream end and the downstream end of the containment tank, while maintaining aquatic life within the at least two compartments segregated from one another. The fluid containment tank is of rectilinear configuration in one embodiment, and non-rectilinear configuration i.e.: circular, oval or crescent shape, in other embodiments. The outer enclosure and support walls of the fluid containment tank are thus of curvilinear configuration in another preferred embodiment. The lowermost floor is of stepped configuration in one embodiment. The lowermost floor is of sloped configuration in a further embodiment. The system may include a filtration system which also generates the current in the tank, fed by water at the downstream end of the containment tank for filtering water and injecting it at the upstream end of the tank. The system may include other types of external filter arrangements utilizing both the downstream end and the upstream end of the containment tank. The system may include a fluid recycling arrangement for recycling water from the downstream end of the containment tank into the upstream end of the containment tank. The divider panels may have a gap extending between their side edges and the outer support and enclosure walls, to permit a narrow flow of water to flow from an upstream compartment to a downstream compartment along the sidewalls of the enclosure and support walls. The divider panels may be of varying or of increasing height-wise dimensions along the downstream direction for the stepped floor.
[0025] The invention also comprises a method of safely maintaining various species of aquatic life in a common containment tank, for the sustained support and segregation of various species of aquatic life in that fluid containment tank, the tank having an upstream water feed end and a downstream water discharge end, comprising: arranging an arrangement of a top cover, enclosure walls and a lowermost floor comprising the fluid containment tank; placing at least one divider panel supported between the exterior walls or by means of support members to divide the tank into at least two compartments, the divider panel having a pair of side edges and a lowermost edge in supported contact with the outer support and enclosure walls; forming a gap between the lowermost edge of the at least one divider panel and the lowermost floor to permit a flow of water therebetween from the upstream end and the downstream end of the containment tank, while maintaining aquatic life within the at least two compartments segregated from one another. The method may include filtering the water as the water is removed from the downstream end of the containment tank. The method may include recycling the water as the water is removed from the downstream end of the containment tank up to the upstream end of the containment tank. The method may include collecting the water at the downstream end and filtering the water before it is fed into the upstream end of the containment tank.
[0026] The invention also comprises a system of safely maintaining, supporting and segregating various species of aquatic life in a common aquatic containment tank, the aquatic tank having an upstream water feed end and a downstream water discharge end, the system comprising: at least one divider panel having side portions and a lower portion, the divider panel arranged across the containment tank to divide the tank into at least two species-segregatable compartments; a pump facilitated filtration arrangement to withdraw water from a downstream end of the system and to recycle the water into the upstream end of the system, the pump facilitated filtration arrangement also creating a flow of current between the at least two compartments; and at least one opening along the lower portion of the at least one divider panel to facilitate the flow of current and any movement of debris from an upstream compartment to a downstream compartment for subsequent filtration and or collection. The filtration system may be arranged at both the upstream water feed end and at the downstream water discharge end of the containment tank. The at least one divider panel is preferably displacably adjustable within the containment tank. The at least one divider panel preferably has an opening along a side edge portion thereof. The aquatic containment tank has a shape preferably selected from the group comprised of: a rectilinear configuration, a curved configuration in a plan view, and a curved configuration in a cross-sectional view.
[0027] Still another variant could draw water from the bottom/floor at one or more location in one or more compartments through slots/holes in the floor or another type of conduit resting on the floor or below for removing water to recreate or reinforce the cleansing currents and establish a bottom current flow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The objects and advantages of the present invention will become more apparent, when viewed in conjunction with the following drawings in which:
[0029] FIG. 1 is a perspective view of the aquatic tank invention in its most basic format, showing the outer walls of the tank and a plurality of divider panels forming a reality of individual compartments within that tank;
[0030] FIG. 2 is a plan view of the aquatic tank shown in FIG. 1 with the divider panels herein, shown spaced unequally along its longitudinal length;
[0031] FIG. 3 is side elevation view of the aquatic tank shown in FIG. 1 where the divider panels shown spaced equally apart along its longitudinal length;
[0032] FIGS. 4A and 4B are sectional views taken along the lines 4 A/ 4 B in FIG. 3 showing the divider panels supported within the side walls and bottom of a tank of the present invention, maintaining their gap between the side walls and the bottom whilst there between while still maintaining a support within those walls to define the various compartments of it within;
[0033] FIG. 5 is a side elevational view of an elongated aquatic tank having a bottom with a stepped configuration and with divider panels of increasing height wise dimension in the downstream direction;
[0034] FIG. 6 is a side elevational view of an elongated aquatic tank having a bottom with a sloped configuration and with divider panels of increasing height wise dimension in the downstream direction;
[0035] FIG. 7 is a plan view of an aquatic tank having a non-linear configuration, in this figure the outer wall is a circular configuration dividing the compartments into pie shaped units with a common wall which marks the beginning of flow on one side and the end of flow on the other side thereof;
[0036] FIG. 8 is an elevational view of the rear side of the elongated tank represented in FIG. 2 , showing a filtration arrangement at both ends thereof for filtering fluid as it exits the tank and again filtering the fluid as it enters the tank;
[0037] FIG. 9 is a plan view of the aquatic tank shown with a filter system arranged on the rear side thereof;
[0038] FIG. 10 is a cross-sectional view of a further embodiment of the aquatic tank, shown in generally crescent shape; and
[0039] FIG. 11 is a plan view of yet a further embodiment of the aquatic tank utilizing bottom/floor water discharge/collection systems, shown in an elongated tank configuration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] Referring now to the drawings in detail and particularly to FIG. 1 , there is shown the present invention which comprises an aquatic system 10 for the compartmentalized maintenance of a plurality of aquatic specimens, such as for example numerous species of fish or the like. The aquatic system 10 in a first preferred embodiment thereof comprises an elongated tank 12 having a first or upstream end wall 14 and a second or downstream end wall 16 , a bottom or floor 18 , and a front wall 20 and a rear wall 22 , as may be seen in FIGS. 1 , 2 and 3 .
[0041] The elongated tank 12 in this particular embodiment is divided into a plurality of compartments 24 by a plurality of spaced apart divider panels 26 . The divider panels 24 are supported transversely across the longitudinal length of the tank 12 by engagement tabs 28 as may be seen in FIG. 4A . Each divider panel 26 preferably has an opening or elongated gap 30 between its lowermost edge 29 in the bottom or floor 18 of the tank 12 as may be seen best in FIG. 3 . Each divider panel 26 also has an opening or elongated gap 32 between its respective side edges 31 and the adjacent inner sidewalls 20 and 22 of the tank 12 , as may be seen in FIG. 4A . The divider panels 26 may be spaced apart a uniform distance as shown in FIG. 3 , or a non-uniform distance from one another, as shown in FIG. 2 , as necessary, for the segregated containment of aquatic species “S 1 , S 2 . . . ” within their own individual compartments 24 .
[0042] The divider panels 26 themselves may be transparent, or partially or fully opaque, or even colored, as desired. Each divider panel may also have openings or perforations 34 therein as shown in FIG. 4A , to further permit fluid flow between successively adjacent compartments 24 . The perforations 34 in any particular panel 26 as well as the gaps 32 along their side edges 31 and the side walls and the gap 30 between the lower edge 29 of the divider panels 26 and the bottom or floor 18 of the tank 12 would be of course smaller than any particular species of aquatic life “S” which was being retained within that particular compartment, in order to maintain their separation from one another. Such perforations 34 and/or gap 30 between the lower edges 29 of the divider panels 26 and the floor 18 may, be for example, about ⅛ to ¼ of an inch depending upon the size and species of aquatic life contained there within. Commercially sized aquatic systems for the farming of fish and/or other species of aquatic life may necessitate larger or smaller gaps. The perforations 34 and gap 30 can also be sized to create unique water flow patterns in one or more specific compartment as may be preferred by a particular species for maintenance and cultivation.
[0043] The purpose of the gaps 30 and 32 is to preferably permit a laminar flow of water to pass between adjacent compartments 24 and thus carry waste, such as fecal matter, food products, detritus and aquatic debris from an upstream end of the flow of water to a downstream end of the flow of water along the floor or bottom 18 of the tank 12 .
[0044] The flow of water “F” for this aquatic system 10 begins at the upstream end of the tank 12 , as for example, to the right as shown in FIG. 3 , through a plurality of slots 38 from a filtration system, such as 40 in FIG. 8 , into each compartment 24 through the gaps 30 and 32 and/or perforations 34 to the opposite/downstream end of the tank 12 where it passes into the first compartment of the filtration system 40 through slots 39 or another means of discharge. The aquatic life in each compartment 24 contribute to the debris and fecal matter which settles gently to the bottom of each compartment 24 and is swept downstream through the gap 30 to the lower edge of each divider panel 26 and the floor or bottom 18 of the tank 12 . In one embodiment of the present invention, the debris and fecal matter seized by the filtration system may be collected for further use in agriculture or the like.
[0045] A further embodiment of the present invention comprises the bottom or floor 52 of the aquatic system having a stepped configuration as viewed from the side, as may be seen in FIG. 5 . In such a stepped embodiment, the sequential downstream divider panels 54 would be increasingly of varying (taller) dimension to accommodate the difference in height due to the stepped bottom thereadjacent, as may also be seen in FIG. 5 . The gap 56 would still be necessary between the lower edge of each divider panel 54 and its adjacent floor portion 52 of its respective compartment 58 , to accommodate and permit a smooth flow of water and the step passage of aquatic debris and fecal matter downstream.
[0046] In yet a further embodiment of the present invention, as represented in FIG. 6 , the bottom or floor 60 of the tank 12 , is of sloped configuration as viewed from the side. In such a sloped embodiment, the downstream divider panels 62 are of increasingly greater height to accommodate the greater depth of that particular compartment 64 . The gap 66 would still be required between the bottom edge of the respective divider panels 62 and the surface of the floor 60 there adjacent.
[0047] The aquatic system in yet a further embodiment thereof may be comprised of a non-linear tank 70 , which for example, one of circular configuration in a plan view thereof, as represented in FIG. 7 . Such a nonlinear tank 70 will have an outer wall 72 and a correspondingly configured innermost wall 74 . The innermost wall 74 is preferably attached to the inside of the outermost wall 72 by a rigid wall panel 76 therebetween that prevents water flow. Such a rigid panel 76 would function as both the beginning or upstream end “U” of the water flow on one side thereof and as the end or downstream portion “D” of the water flow on the other side of that rigid panel 76 . Each respective side of that rigid panel 76 would have a filtered water source 78 or a used water extractor 80 arranged respectively thereat. The divider panels 82 in such a nonlinear tank 70 would divide the volume of that tank into “pie” shaped compartments 77 , as may be seen in FIG. 7 . Each divider panel 82 would of course have a gap 84 between its side edges and the inner wall and a gap 86 at the inside edge of the outer wall as well as the lower edge of that panel and the floor or bottom of the tank 70 , as is represented in FIG. 7 .
[0048] A still yet further embodiment has a filtration system 40 , as shown in FIG. 8 that withdraws compartment tank water at one end 39 of the elongated tank and discharges filtered water at the opposite end 38 thereby creating the current and the means, both filtration and other natural and anthropogenic means, to thus treat cleanse by filteration the main compartment tank. The filtration system 40 is attached to the rear of the aquatic tank 12 by any water tight means provides processing/treatment of the water and establishes the current “F” cleanses the aquatic compartments 24 . In this embodiment, the water enters the filtration system through the plurality of slots 39 that withdraws compartment 24 tank water at one end of the elongated tank 12 into the first filter compartment 42 , shown in FIG. 8 containing slots 39 and a filter/bio media, and passing the water through the filter media into a drip tube 45 that drips water into the second filter compartment 44 over additional filter/bio media 43 where it is then pumped 46 into the third filter compartment 48 and flowing through additional treatment means. Proposed variants of this embodiment, not shown in the figures include additional natural and anthropogenic filtration/treatment means such as natural media like gravel, rock, charcoal, wood and plant material and manmade treatment media like photonic sterilizers, chemical treatment systems, protein skimmers, aerators and other electronic and mechanical devices/means.
[0049] FIG. 9 shows the aquatic tank 12 with an attached filter system 40 arranged on the rear side thereof, with additional filter system compartments 42 , 44 , and 48 created with an additional rear wall, side walls, bottom floor panel and two rigid/wall divider panels. The filtration system withdraws the compartment tank water through the slots 39 and discharges filtered water at the opposite end through the slots 38 thereby creating a current “F” to cleanse the aquatic tank. This embodiment of the filter system illustrated in FIG. 9 shows three filter compartments, 42 , 44 and 48 attached to the compartmentalized tank system 12 that is the front of the aquatic system. The water flow “F” within that tank system 10 creates the cleansing current that is an embodiment of this invention.
[0050] A further aspect of the present invention is the method of maintaining similar or different aquatic specimens or fish in sequentially altered water from the downstream currents within the longitudinal tank 12 or the non-linear tank 70 by using other specimens in preceding compartments or by introducing substances to allow and promote exchange of chemicals or stimulants between the specimens as a process in culturing, nursing or maintenance of the downstream specimens.
[0051] A still further aspect of the present invention comprises the use of a retrofit arrangement for use within an existing tank, as a kit, comprised of notched elongated supports 36 to enable the support of one or more divider panels 26 therewithin, as represented in FIG. 4B , so is to subdivide a tank 12 or 70 , by those panels 26 or 76 , while maintaining a changeable compartments 24 or 77 between those panels 26 or 76 , and the flow of water along the floor of the tank 12 or 70 under and around the side of the tank's walls.
[0052] In yet a further aspect of the present invention, the aquatic tank 10 may have a cross-sectional shape of crescent shape, as represented in FIG. 10 , having side portions 98 , and a bottom-most portion 100 , with a divider panel 102 , shown arranged in a supported manner therewithin. The divider panel 102 has an arrangement of side openings 104 corresponding with the side portions 98 of the aquatic tank 10 represented here as of crescent shape, and with a bottom opening 106 , shown here corresponding to the bottom-most portion 100 of the aquatic tank 10 .
[0053] FIG. 11 illustrates still yet a further embodiment of the present invention the aquatic tank 10 that substitutes the bottom gap or adds to the cleansing ability of the bottom gap 115 with a water withdrawal mechanism such as floor holes/slots 111 , a conduit 112 or other type of plenum 113 thereby removing water from the compartments, In this embodiment the divider panels can also be fixed 114 and/or without a lower gap 115 such as may be used in large or commercial scale aquatic tanks. The influx of water can be supplemented with additional inflows 116 at locations that help recreate/supplement the cleansing currents.
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An aquarium or aquatic system such as a fish tank for the safe and clean containment of a plurality of aquatic specimens such as fish, segregated from one another by a series of divider panels aligned within that tank. The divider panels are spaced from the walls and floor of that tank so as to permit a “bottom current” flow of water under those divider panels to sweep away the debris accumulating in each of those chambers, and then into a collection unit such as a series of filters, filtration system or water processors which thus treats and cleans the water and preferably reintroduces that water back into the upstream end of that water flow.
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FIELD OF THE INVENTION
The present invention relates to a method and a device for obtaining subterranean soil samples and for obtaining and retaining material samples including loose grains.
BACKGROUND OF THE INVENTION
Cone penetrometer testing (CPT) is commonly used for the geotechnical and environmental characterization of subterranean media. Some aspects of this characterization require the analysis of samples of soil retrieved from subterranean layers. Appropriately used, CPT has become a cost effective alternative to other methods for obtaining precise stratigraphic and chemical information to depths over 300 feet below the surface of the ground.
A CPT system typically involves the deployment of a cylindrical probe through subterranean media at a constant velocity specified by industrial standards. Sensors are housed in the cylindrical probe having a conical point that is pushed vertically without rotation into the ground via hydraulic or other constant velocity ram systems. As the probe advances, additional cylindrical tubes or rods are added to a string of tubes or rods to increase the effective length of the probe.
The vertical load exerted on the probe as it is advanced can exceed thirty tons of force. This force is preferably developed by the dead weight of the vehicle to which the ram system is attached or alternatively by a reaction against earth anchors.
The lower end of the CPT probe, approximately 1.5 inches in diameter, contains load sensors for measuring the vertical bearing load on the conical surface section of the probe and the vertical frictional or shear load on the external surface of a short cylindrical section disposed immediately above the conical surface section. These two loads are measured at multiple intervals of depth or time to produce a continuous representation of various geomechanical soil properties as a function of depth. In addition, empirical correlations are commonly used to develop stratigraphic maps from these load measurements.
Optionally, additional sensors are deployed within the probe to measure the pressure of the pore fluid, electrical resistance and moisture content of the soil matrix, alkalinity and oxidation reduction potential of the subterranean media, and seismic velocity response to an imposed surface wave to derive soil bulk modulus. After the desired depth or maximum advisable push load is obtained, the probe and connecting rods are typically removed from the ground.
Because of the efficiency of the CPT device push method, CPT push systems have been adapted to push other types of devices into the ground. Specifically relevant to this invention, these devices often include material sampling tools. Several devices have been previously developed for obtaining samples of soil, pore fluid and pore vapor. Desirable qualities of such tools should be that they withstand the extreme normal and shear loads applied to CPT-deployed probes during the push and retrieval processes, that they reliably obtain a quality sample of media from the area of interest, that they retain the sample during retrieval, and that they are easy to unload and redeploy without cross-contaminating additional samples.
Several attempts have been made to develop a soil sampler that embodies these qualities. Those designed to be opened after being pushed to the desired sampling depth have previously utilized two tip release devices and methods.
The first such device consists of load-bearing keys disposed between a movable tip assembly and an outer housing. The keys are displaced by inertial means when the housing is pulled upward with respect to the tip assembly. With the keys displaced, the housing can be driven further into the soil, thereby moving the housing relative to the movable tip assembly.
The second device releases a similar movable tip assembly by means of a lanyard lowered through an inner diameter of the cone rods, once the sampler has been pushed to a desired depth. The tip assembly includes hardened steel balls projecting radially outward into an inner radial groove within the housing. The lanyard engages and is secured to an upper portion of the tip assembly, which when displaced upward with respect to a lower portion of the tip assembly allows the steal balls to move radially inward out of the groove, thus releasing the tip assembly. Further upward motion of the lanyard pulls the tip assembly, both upper and lower sections, through the outer housing until reaching the upper end of the sampler.
Upon reaching the upper end of the sampler, an appropriate device fixed to the housing disengages the lanyard from the tip assembly to facilitate the removal of the lanyard prior to the retrieval of the sampler. The present invention improves upon the second device heretofore described.
Other devices exist which have been improved upon by the development of the devices described above. Such devices include samplers which do not provide a sealing means between the tip assembly and the outer housing prior to tip release and samplers which do not provide sufficient sample volume or reliable means for retaining the sample during retrieval.
The above-described soil sampling devices have several shortcomings.
The device of the first type described, using locking keys, relies upon inertial forces to release the locking mechanism between the tip and the housing. Such inertial forces presume a vertical push direction, parallel to normal gravitational forces. However, certain circumstances require pushing at an acute angle to vertical, such as when attempting to secure a sample underneath an object, for example, a storage tank, in which case the locking keys do not reliably disengage. Even during vertical pushes the keys may fail to disengage, at which point the operator has no indication that a failure has occurred until the sampler is retrieved.
Additionally, the release method requires the keys to be separate objects which must be manually set in place when assembling the sampler between each sampling operation. The use of appropriate environmental field apparel, such as work gloves, impedes the installation of such individual keys and makes field assembly difficult. Further, the release method of pulling upward on the outer housing disallows a common procedure of repeatedly displacing the rods up and down a few inches to work the probe through thin hard layers of soil. This procedure, commonly called "cycling", causes the tip assembly of this type of soil sampler to prematurely release before reaching a desired depth.
In addition, samplers of this type do not reliably retrieve samples from weak saturated soil layers because the weight of the released tip assembly bears upon the soil to be sampled as the housing is advanced. This weight prevents the soil from entering the sample chamber as required, as even small normal forces exacerbate the phenomenon of granular arching at the opening of the sample tube. Non-cohesive soils also present a difficulty to this tip release mechanism, as there must be sufficient retention of the conical tip surface in the soil to keep the tip from moving upward when the housing is raised to release the locking keys. Non-cohesive sandy soils, therefore, often keep the tip from releasing as required.
While attempting to address some of the above-described shortcomings by providing a means to actively release the locking mechanism, pull the released tip assembly through the sample chamber and retain it at the top of the chamber, prior examples of samplers of the second type described have had their own shortcomings. For example, the load bearing area, between the locking steel balls and the mating grooved surface, has not been sufficient to withstand the contact forces developed by pushing the sampler in harder geologic materials. The result in several instances is that the housing member containing the grooved surface will fracture during pushing. Another result of the high contact loads is that the grooved surface will deform with repeated loading and will have to be replaced.
The mechanical arrangement of balls in a groove is common to the design of radial ball bearings and works well for large radial loads combined with minor axial loads. The nature of this application to soil samplers requires the mechanism to withstand relatively high axial loads and almost no radial load.
Attempts to remove this limitation in current designs have been largely unsuccessful as they have compromised ease of use. In addition, samplers of this type have been unable to reliably obtain samples of loose, granular material which flow back out of the sample chamber during retrieval. Further, decontaminating the tip assemblies of such samplers has proven difficult due to the large number of individual members comprising the tip assembly and numerous small crevices which retain sample media.
SUMMARY OF THE INVENTION
The present invention provides an apparatus and method for obtaining a subterranean soil sample. The inventive method comprises the step of inserting the inventive apparatus into the ground. The inventive apparatus comprises an elongated housing having a passageway or sample chamber extending longitudinally therethrough, a tip assembly having upper and lower portions, a locking assembly, and a device lowered through the housing to release the locking assembly.
The elongated housing has three or more sections: a lower section, a middle section and an upper section. The tip assembly is positionable within the lower section of the housing such that a point of the tip assembly protrudes through a lower opening in the lower section and is prevented from moving further through the opening. The tip assembly comprises an upper portion, a lower portion and locking keys located there between which protrude radially into a groove in the lower section of the housing to prevent upward motion of the tip assembly with respect to the housing.
The tip assembly is designed such that when the upper portion is pulled upward and separated a predetermined amount with respect to the lower portion by means of a deployable lanyard, the locking keys are free to swing inward out of the radial groove in the housing. The locking keys are free to pivot on pins which are disposed between the upper and lower portions of the tip assembly. Further upward motion of the upper portion of the tip assembly also raises the lower portion and the locking keys, which are forced inward by acting against a tapered upper surface of the grooved surface in the housing, thereby releasing the tip assembly to be pulled through the middle section of the housing and into the upper section.
The present invention also provides a mechanism, in the form of an O-ring or other mechanical seal between the upper portion of the tip assembly and the inner surface of the middle and upper sections of the housing, to create a partial vacuum beneath the tip assembly as it is drawn through the housing during the sampling process, thereby assisting in the collection of very wet or granular materials within the sample chamber and in the retention of such materials within the chamber during retrieval.
After the tip assembly is retained in the upper section of the housing, the housing is lowered as required to fill the middle section of the housing with the desired sample of a volume of at least about 12 cubic inches, and preferably at least about 18 cubic inches. An optional resilient member acting as a one-way valve between the lower and middle sections of the housing can be used to retain granular material within the middle section during retrieval. This resilient valve can be in the form of a flexible ring with multiple curved members attached to the ring around its perimeter with little space between members so as to allow the passage of the tip assembly and soil up through the passageway but to effectively seal the passageway against downward material flow. The middle section of the housing can be fitted with removable sleeves to assist with sample removal once the sampler has been retrieved, and multiple middle sections can be used to increase the potential sample length.
In contrast to the soil sampling tools and methods used heretofore, the present invention allows the reliable collection of high quality soil samples through hard materials in a variety of media including loose granular wet sands, even during nonvertical sampling. Push loads of 20,000 pounds or more can be used as is required to traverse tough geologies and bring back a reasonably undisturbed sample of sufficient volume and diameter to meet most current environmental and geotechnical sampling requirements.
The inventive apparatus allows unlimited cycling of the sample tool to penetrate hard materials without premature release of the tip assembly, greatly increasing the potential benefits of CPT technology over alternate sampling methods. The ultimate strength of the inventive apparatus to withstand large push loads has been improved over previous devices that utilized lanyard release mechanisms, such improvement being effected by replacing locking balls with locking keys which provide a much higher load bearing area. In addition, the locking device is operated manually by the operator, providing tactile feedback through the lanyard cable that the release mechanism has functioned successfully.
Furthermore, securing the locking keys pivotably about pins eliminates the nuisance of losing components in the field and allows a simplified assembly procedure. In addition, the creation of a partial vacuum underneath the tip assembly by the method described herein improves upon the ability of previous sampling tools to reliably collect and retain a sample of wet or granular soil.
Accordingly, it is an object of the present invention to provide a soil sampler system including a housing and a tip assembly initially fixed at a leading end of the housing and movable towards the trailing end of the housing for obtaining a subterranean sample with the tip assembly including an upper portion and a lower portion movable with respect to each other within the housing and having at least one locking key pivotally mounted between the upper and lower portions and a portion of the locking key extending beyond a periphery of the upper and lower portions and engaging the housing when the tip assembly is fixed at the leading end of the housing and a portion of the locking key moving away from the housing and in between the upper and lower portions when the upper and lower portions move with respect to each other and together move towards the trailing end of the housing.
It is another object of the present invention to provide a soil sampler system including a housing and a tip assembly with the tip assembly including locking keys for fixing the position of the tip assembly at a leading end of the housing during penetration of the soil sampler system to a predetermined depth and upon lowering of a tip release bar to the tip assembly and engaging release latches, moving the tip assembly upwardly through the housing so that the tip assembly is released from engagement with the side wall of the housing and its fixed position for rearward movement within the housing while simultaneously creating a vacuum ahead of the tip assembly for ensuring retention of a soil sample upon further forward movement of the housing into the soil.
It is still yet another object of the present invention to provide a soil sampler system having a housing and tip assembly fixed at a leading end of the housing and have a soil catcher basket through which the tip assembly is slidable while simultaneously creating a vacuum ahead of the tip assembly to aid in retention of soil in conjunction with the soil catcher basket as the housing is further advanced into the soil.
Further objects, features, and advantages of the present invention will be readily apparent to those skilled in the art upon reference to the accompanying drawings and upon reading the following description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 provides a longitudinal sectional view of one embodiment of the soil sampling apparatus of the present invention.
FIG. 2 provides a cross-sectional view of the inventive sampling apparatus taken along line 2--2 of FIG. 1, showing the pivotally mounted locking keys of the locking mechanism.
FIG. 3 provides an enlarged sectional view of the tip assembly as shown in FIG. 1, in the locked position with the locking keys engaging a sidewall of the housing.
FIG. 4 provides an enlarged sectional view of the tip assembly shown in FIG. 1, however, in the released position with movement of the upper portion of the tip assembly up through the housing as pulled by a tip release bar to cause a chamfered edge of the locking keys to contact an inclined surface in the groove of the housing to pivot the locking keys inwardly and allow movement of the upper and lower portions of the tip assembly up through the housing.
FIG. 5 illustrates the tip assembly holding the locking keys in an extended position between the upper and lower portions of the tip assembly.
FIG. 6 illustrates cable secured to a tip release bar for engaging release latches of the tip assembly to separate the upper and lower portions of the tip assembly to a predetermined extent and allow inward pivoting of the locking keys for release of the tip assembly from the lower section of the housing and movement of the tip assembly up through the housing.
FIG. 7 is an exploded of the housing containing the tip assembly and a sample tube.
FIG. 8 is an exploded view of an alternative sample tube and tube caps.
FIG. 9 is an exploded view of the tip assembly.
FIG. 10 is an exploded view of the cable and tip release bar.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
With reference to the drawings, in general, and to FIGS. 1 through 4, in particular, a soil sampler embodying the teachings of the subject invention is generally designated as 20. With reference to its orientation in FIG. 1, the soil sampler comprises a housing 30 and a tip assembly 40. The housing includes an internal bore of approximately 1.1 inches in diameter, and preferably at least about 1.375 inches in diameter.
The tip assembly 40 is shown locked in the leading end 32 of the housing 30. This is the position in which the housing will be driven into the ground following CPT procedures.
At the trailing end 34 of the housing 30 is a threaded passageway 36 for receipt of hollow tubing in threaded engagement for driving the soil sampler into the ground. After a predetermined extent of driving the soil sampler into the ground, the tip assembly is movable towards the trailing end 34 of the housing by release of its locking engagement at the leading end 32 of the housing 30.
With reference to FIG. 3, the locked position of the tip assembly is shown in greater detail. In this Figure, the upper portion 42 and the lower portion 44 of the tip assembly are shown. The lower portion 44 includes a conically shaped tip 46.
Located between the upper and lower portions 42, 44 are two locking keys 48. The locking keys are slidably mounted on a respective pin 50 which acts as a pivot pin for each of the locking keys 48. The pins 50 are fixed at one end to one of the upper and lower portions 42, 44 and is slidable into the other of the upper and lower portions 42, 44. Accordingly, in FIG. 3, the pins 50 are concealed, having slid, for example, into body block 52 and therefore are concealed in the drawing.
When the upper and lower portions of the tip assembly are adjacent to one another as shown in FIG. 3, the locking keys project beyond the periphery of the upper and lower portions 42, 44, respectively, as shown in FIG. 5. The portion of the locking keys projecting beyond the periphery of the upper and lower portion is engaged in the groove 54 located in an interior sidewall of the housing 30.
A stem 140 projecting from the body block 52 includes a shoulder 142, a tapered portion 144 and a cylindrical portion 146. As shown in FIG. 2, a diameter of the shoulder portion 142 is dimensioned to match a curvature of one side of the locking keys 48. The opposite side of the locking keys project into groove 54 in the sidewall of the housing 30 and are locked in place when the locking keys 48 engage the shoulder 142 of stem 140.
When the upper and lower portions of the tip assembly are separated, as shown in FIG. 4, and the tip assembly is moved towards the trailing end 34 of the housing 30, cylindrical portion 146 of stem 140 is located adjacent to the keys 48. Continued movement of the cylindrical portion 146 out a bushing 148 in lower portion 44 of the tip assembly 40, causes engagement of a terminal end of the cylindrical portion 146 with an end of the bushing 148. The upper and lower portions of the tip assembly then slide together towards the trailing end 34 of the housing 30.
Meanwhile, a chamfered edge 56 of the locking keys 48 engages an inclined surface 58 of the groove 54 to pivot the locking keys about pins 50 towards cylindrical portion 146 and into the gap 60 formed between the upper and lower portions of the tip assembly. The chamfered edge 56 is inclined at a chamfer angle, with respect to a longitudinal axis of the housing of between about 50 and 70 degrees, and preferably about 60 degrees. This angle provides proper operation of the keys over a wide range of push angles. If the angle is too large, the keys will not easily disengage the housing shoulder (inclined shoulder 58); if they are too small, the housing hoop stress becomes to large. The total projected area of the shoulder-engaging chamfer of the key, in a transverse plane, should be at least 0.1 square inches, and preferably at least 0.141 square inches to withstand heavy or dynamic pushing. The cumulative area of all the keys should be at least 0.25 square inches, and preferably 0.275 square inches.
Accordingly, when the upper and lower portions of the tip assembly are adjacent to each other it is not possible for the locking keys to pivot out of engagement from the grove 54 (as restrained by shoulder 142), thereby locking the tip assembly at the leading end 32 of the casing with the tip 46 projecting therefrom.
The soil sampler is assembled as will be explained with reference to FIGS. 7, 8 and 9.
After cleaning and decontamination of the components of the soil sampler, an upper O-ring 62 and a lower O-ring 64 are placed in O-ring grooves 66, 68, respectively, of the tip assembly 40. The lower O-ring 64 seals the tip 46 in the cutting sleeve 70 of the housing 30 so that soil and water cannot enter the sampler prior to obtaining a sample and so that soil will not jam the tip in the cutting sleeve. The upper O-ring 62 produces a vacuum in the sample tube 72 during retraction of the tip 46 to help ensure positive sample retention. Upper O-ring 62 also secures the tip 46 inside the tip catch housing 74 of the housing 30 following tip retraction. The tip assembly 40 and cutting sleeve 70 can be lubricated with a light coat of vegetable oil, cooking spray or other permissible lubricant to provide smoother operation.
With the tip assembly in a vertical position, with the tip pointing down, the tip assembly is slid down through the locking sleeve 76 of housing 30 with the locking keys 48 manually moved inwardly into their unlocked position, until the O-ring 62 rests on a shoulder 78 of the locking sleeve 76 adjacent to groove 54.
The cutting sleeve 70 is slid upward over the tip 46 of the tip assembly 40 and threaded into the bottom of the locking sleeve 76. This will force the locking keys 48 outward into the locked position as the upper portion 42 of the tip assembly 40 is lowered towards the lower portion 44 for threading of the cutting sleeve 70 into the locking sleeve 76.
A soil catcher basket 80, domed end 82 up, is slid over the tip assembly 40 until it seats against the locking sleeve 76. The catcher basket includes a plurality of wedge shaped members 84 extending from a base ring 86 to an apex 88. The wedges 84, being anchored at only one end can be separated for passage of material, such as a soil sample, up into the housing 30.
An upper sleeve 90 is threaded into the top of the locking sleeve 76. A barrel 92 of the housing 30 is threaded into the upper end of upper sleeve 90.
Cylindrical sample tube 72 is inserted into the barrel 92. Alternatively, split sample tube sections 94, 96 (as shown in FIG. 8) can be used in place of the cylindrical sample tube 72.
The tip catch housing 74 is then threaded into the upper end of barrel 92. All threaded connections are gently tightened with adjustable wrenches.
The soil sampler is maintained in a vertical orientation until it enters the ground to ensure that the upper portion 42 of the tip assembly 40 does not slide upward, which would permit the locking keys 48 to disengage from groove 54 and move into the thus formed gap 60 in the interior of locking sleeve 76. The sampler is now ready to be pushed into the ground.
To obtain a soil sample, the soil sampler of the present invention is attached to the CPT rods by threading the bottom CPT rod into the threaded opening 36 of the upper end of tip catch housing 74. Care is taken to keep the soil sampler vertically oriented with the tip 46 down at all times to ensure that the tip assembly 40 remains locked in position.
After pushing the soil sampler to the desired depth, tip release bar 102 joined at coupling 104 with cable 106 is lowered through the push rods until the tip release bar 102 enters into a gap 108 between opposed latches 110 as shown in FIG. 4. The housing 30 of the soil sampler is retracted a small amount to relieve the soil pressure at the tip 46.
To release the tip from its locking position, the cable 106 is pulled upwardly. If there is no resistance, this means that the tip release bar has not engaged the latches 110. If this happens, the cable is pulled up about half a meter (20 inches) and dropped. The release bar 102 should then be engaged in the gap 108 between the latches 110 of the tip assembly by overcoming the inward bias of the latches 110 from spring 112.
The cable is pulled up until the upper portion 42 of the tip assembly has moved away from the lower portion 44 to an extent limited by stem 140 and pins 50. The upper and lower portions are then moved together as a unit until reaching the top of the tip catch housing 74 (about 0.6 meters or 2 feet). During initial movement of the upper and lower portions 42, 44 together, the chamfered edges 56 of locking keys 48 engage inclined surface 58 of groove 54 to move the locking keys into the gap 60 formed by the separation of the upper and lower portions 42, 44.
At the top of tip catch housing 74, the inclined planes 114 of the latches 110 engage the unlatch tube 100 to spread the latches 110 apart and release the tip release bar 102. The tip release bar is then retracted to the surface.
The housing 30 is then advanced by pushing on the CPT rods to fill the sample tube 72. A quasi-static load of at least 10 tons can be applied to the sampler to advance the sampler through the ground. The push distance required to fill the tube will vary with soil conditions. A push distance of about 0.61 meters (2.0 feet) is preferred. Alternatively the tip assembly can be held in place while the housing is advanced to obtain a soil sample.
The CPT rods and the soil sampler is then retracted to the surface. The tip catch housing 74 is then unthreaded from the barrel 92. The tip assembly 40 can be removed from the tip catch housing 74 by shaking the housing 74.
The filled sample tube 72 is removed from the barrel 92. The sample may be extruded from the sample tube 72 in the field or the entire tube may be sealed for later shipment or analysis by capping it with two sample tube caps 116.
To assembly the tip assembly 40, one of the release latches 110 is placed into the release body 118 and pinned with roll pin 120 passing thru hole 122 in the body 118 and hole 124 in the latch 110. Spring 112 is pushed into the recess 126 on the other release latch 110. This assembly is placed into gap 108 in the release body 118 carefully aligning the spring 112 with the first latch 110. The other roll pin 120 is then inserted thru opening 122, 124. O-ring 62 is installed in the O-ring groove 66 in the release body 118. The two locking keys 48 are installed over the pins 50 on the tip receiver 44 making sure that the chamfers 58 on the keys 48 face upward and that the keys 48 pivot freely on pins 50.
The tip receiver 44 is secured to the release body 118 by passing roll pins 128 thru openings 130 in the release body 116. The pins 128 pass thru slots 132 in posts 134 extending from tip receiver 44.
Tip 46 is screwed into the tip receiver 44 and tightened with an adjustable wrench and a pipe wrench. O-ring 64 is then installed in the O-ring groove 68 in the tip 46.
The release body 118 and tip receiver 44 are thereby movable with respect to each other, limited by the pins 128 sliding within the slots 132 and by cylindrical portion 146 sliding in bushing 148. At the furthest limit of a separation of the release body 118 and the tip receiver 44, a gap 60 is formed which allows receipt of the locking keys 48 in their inwardly pivoted position.
The foregoing description should be considered as illustrative only of the principles of the invention. Since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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An apparatus for obtaining subterranean soil samples includes an elongated housing having a passageway extending longitudinally therethrough, a tip assembly movable through the passageway, and a locking device for releasably preventing the tip assembly from moving from a first portion of the passageway to a second portion of the passageway. The sampling method includes the steps of inserting the sampling apparatus into the ground, unlocking the tip assembly, pulling the tip assembly through the passageway and retaining the tip assembly in the second portion of the passageway. A device is provided for creating a vacuum pressure above the sample material as the tip assembly is retracted and for retaining the sample material in a sample chamber.
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BACKGROUND OF THE INVENTION
This invention relates generally to chairs which need to be moved sidewise from time to time. An example described here to illustrate one application of the invention is a chair used by a fisherman and mounted on a rear boat seat bench or thwart. For fishing, the chair should be centered for proper balance and to facilitate fishing from both sides of the boat. For operating an outboard motor, however, the fisherman must move to one side so he can reach the motor controls and operates the steering tiller which are centered at the stern.
While comfortable chairs, some complete with tiltable backs, upholstery, and swivel bases, are marketed with clamps for mounting them on boat seat benches or thwarts, they have heretofore been limited to use on forward or intermediate seat benches. Prior to the present invention, such a chair has not been used on the rear seat because, if clamped in the middle for fishing, it would interfere with operating the motor and tiller. No apparatus has been available to readily shift such a chair sidewise between locked center and offcenter positions.
SUMMARY OF THE INVENTION
Therefore, it is a general object of the present invention to provide an adjustable mounting device enabling sidewise movement of a chair along a seat bench or other support so the chair can be locked and used in a plurality of transversely shifted, fixed positions. While advantageous for use on boats, the invention is not limited to that particular use.
Another object is to provide such a device which can readily be clamped on and removed from a seat or bench as needed.
Another object is to provide such a device having clamps which are readily adjustable for different thicknesses and depths of seat benches.
Another object is to provide an adjustable chair support device for boats and other applications comprising an elongated body adapted to be mounted on the top of a seat bench, a chair-supporting carriage movable sidewise along a floor plate in the body, clamps for mounting the body on the seat bench adjustable for different heights and depths of seats, and a manually operable latch pin on the carriage engageable with a selected one of a plurality of detent openings in the body to lock the carriage in a center or offcenter position as selected.
Another object is to provide the carriage with wheels bearing on the floor plate and a pair of upstanding guide rails on the floor plate engaging the wheels to guide the carriage for movement in a substantially straight line without rubbing against the body.
Another object is to provide at least two clamps on the front or back sides of the body symmetrically disposed with respect to the center of the body, and at least one clamp on the opposite side to achieve a stable, three-point connection between the body and the seat bench.
Another object is to provide brackets on the clamps which engage the lower corners of a seat bench to restrain the body from both vertical and horizontal movements.
Another object is to provide horizontal threaded connections between the clamps and body within a concealed space in the latter to adjust the clamps to different depth seat benches, and to provide vertical threaded connections between the clamps and brackets to accommodate different height seat benches.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages will be apparent from the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of a typical fishing boat showing one application of the present invention;
FIG. 2 is an enlarged front view of the invention seen generally in the direction of the arrows 2--2 in FIG. 1 but without the boat seat bench;
FIG. 3 is a plan view of FIG. 2;
FIG. 4 is a vertical cross-sectional view taken along line 4--4 of FIG. 3 with a cross-section of the boat seat bench;
FIG. 5 is a fragmentary end view of FIG. 3 as seen in the direction of the arrows 5--5;
FIG. 6 is a fragmentary-sectional view of FIG. 3 taken along the line 6--6; and
FIG. 7 is a fragmentary, cross-sectional view similar to FIG. 4, without the boat seat bench, showing an equivalent, slightly modified version of the invention.
Like parts are referred to by like reference characters.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the specific embodiment of the invention shown in the drawings, FIG. 1 illustrates a typical boat 20 fitted with an outboard motor 22 which may be used in recreation or fishing and showing one application of the present invention. It has rear, intermediate, and forward seat benches or thwarts 24, 26 and 28, respectively. Normally, the rear seat bench 24 is occuplied by the person operating the motor 22. From there, the motor controls and tiller handle 30 are within easy reach when the operator is seated far over to the side.
The adjustable chair support device of the present invention is generally designated 32. It is clamped to the rear seat bench 24 and supports a comfortable, cushioned chair 34 for sidewise movement between a plurality of fixed positions, two of which are shown in solid and broken lines in FIG. 1.
Device 32 comprises an elongated body 36, clamp means 38, a carriage 40, and latch means 42.
As shown in FIGS. 3 and 4, the body 36 comprises a hollow, lower base 44, a pair of front and back upper channels 46 and 48 respectively, and opposite end walls 50, 50. In addition to providing cross connections to rigidify the body, the end walls 50 function as stops for the carriage at both ends of its travel. Each of the channels 46 and 48 consists of a vertical web 52 with upper and lower inwardly extending horizontal flanges 54 and 56 respectively. The lower flanges 56 have upstanding parallel guide rails 58, 58 to guide the carriage for movement in a straight line as will be described. As best shown in FIGS. 2 and 3, each end wall 50 comprises a vertical web 59 and a pair of inwardly extending vertical flanges 60, 60 fastened by bolts 62 between the webs 52.
The hollow base 44 comprises a horizontal floor plate 64, downturned vertical walls 66, 66, and inwardly extending lower horizontal flanges 68, 68. A plurality of braces 70, illustrated as short sections of angle members affixed as by welding beneath the plate 64, are spaced inwardly from the front and back walls 46 and 48 and are aligned with individual clamps of the clamp means 38 to provide auxiliary support for the clamps as will be described.
Thus, viewing the construction broadly, the body 36 comprises a front wall 72 consisting of vertically aligned sections 52 and 66; a rear wall 74 likewise consisting of vertically aligned sections 52 and 66; and floor plate means 76 consisting of floor plate 64 and lower flange portions 56, 56 of channels 46 and 48. Spaced parallel guide rails 58, 58 extend upwardly, and braces 70, 70 extend downwardly, from floor plate means 76.
FIG. 7 shows an equivalent, slightly modified form of body which, to distinguish it from body 36, is designated 36a. The construction is fabricated or cast integral instead of being made up of separate components as shown in FIGS. 1-6. Each of the front and rear walls 72 and 74 comprises integral wall sections 52a and 66a. The floor plate means 76 is a single plate instead of the combination of plate 64 and flanges 56, 56 shown in FIG. 4. The upstanding guide rails 58a are integral with the floor plate means 76 instead of being turned-up ends of flanges 56, 56 as shown in FIG. 4. And the depending braces 70a are integral with the floor plate means 76 instead of being separate angle sections as shown in FIG. 4.
Thus, the horizontal floor plate means 76, whether fabricated as shown in FIG. 4 or in FIG. 7, is interconnected between the front and back walls 72, 74 at a location which is vertically intermediate the tops and bottoms thereof to provide a lower space 78 and an upper space 80 respectively below and above the floor plate means 76.
As best shown in FIGS. 2, 3 and 4, the clamp means 38 comprises a plurality, in this case, three, individual clamps 82. Each includes a right angled rod 84 and a corner engaging saddle member 86. Each rod 84 has horizontal and vertical threaded legs 88 and 90 respectively. Two of the clamps 82 are located at the front of the body, equally spaced symmetrically with respect to the center, and a single clamp 82 is centrally positioned at the back. The three clamps are best shown in FIG. 3.
As best shown in FIGS. 4 and 7, each clamp horizontal leg 88 extends through an opening 92 in one of the front or back walls 72 and 74, and through another opening 94 in one of the braces 70 or 70a. Threaded nuts 96 and 98 hold the clamp rods in fixed horizontal adjustment. These nuts and horizontal legs of the adjustment rods and braces 70/70a are effectively concealed within the lower space 78 beneath the floor plate.
Each saddle member 86 includes a tubular section 100 through which the vertical leg 90 extends and a right angle section 102 shaped to grip the lower corners of the seat bench 24. The seat bench, as shown, is of conventional construction comprising an aluminum shell 104 with a fore-and-aft depth D and vertical height H filled with flotation material 106. Sections 100 and 102 may be connected in any suitable way, as for example by welding, brazing or by being fabricated integral. Each is held against a lower corner of the seat bench by a nut 108.
By adjusting each pair of nuts 96, 98, the clamps 82 can be shifted horizontally to accommodate different depths D of the boat seat bench; and by adjusting all of these sets of nuts at both the front and back, the chair 34 can be shifted to a comfortable fore or aft position on the seat bench. When nuts 108 are tightened, the saddle members 86 automatically accommodate varying seat heights or thicknesses H.
The carriage 40 comprises a horizontal plate 110 with a pair of downturned vertical flanges 112. As best shown in FIG. 6, the carriage has, at one side, a downturned flange 114 connected between flanges 112, 112, and an inwardly extending, lower horizontal flange 116. A pair of wheels 118 are fastened by axle bolts 120 to each flange 112. As best shown in FIGS. 4 and 7, the upstanding guide rails 58 and 58a are positioned closely adjacent the inner sides of the wheels to keep the carriage centered between front and back walls 72 and 74. Thus, the carriage is freely movable in a straight line without dragging or rubbing the webs 52 or 52a of walls 72 and 74. The carriage is held against displacement upwardly by flanges 54, 54 which extend inwardly over it.
The carriage has four bolts 122 for fastening to a ball swivel bearing member 124 at the bottom of the chair 34.
As best shown in FIG. 6, the latch means 42 comprises a vertical latch pin or rod 126 which is vertically slidable in holes 128 and 130 provided in the carriage top plate 110 and flange 116 respectively. A coil spring 132 encircles the pin and is compressed between the underside of the carriage plate 110 and a cotter pin 134. An external handle 136 is readily accessible to a person sitting on the chair 34 to lift the latch against the bias of the spring.
A plurality (in this case, five) of detent openings 138 are provided in the floor plate 64 to receive the latch pin 126 and lock the carriage and chair in a selected center or offcenter position.
Use and operation are believed to be obvious in view of the above. Briefly, however, when runing the boat by means of the motor 22, the operator moves the carriage 40 and chair 34 to the side as far as possible where they will be locked in fixed position by engagement of the pin 126 in the extreme left hand detent hole 138 as shown in FIGS. 1, 2 and 3. In this position the operator can readily manipulate the motor controls and the tiller handle 30. When the boat is docked or anchorred, the operator simply pulls the pin 126 upward to release it from the detent opening and moves the carriage with the chair to the center position where the pin engages the center detent opening 138 and locks the chair in place.
While specific examples of the present invention have been shown and described for purposes of illustration, it will be apparent that changes and modifications in construction and in end use of the invention may be made without departing from its broadest aspects. For example, the invention may be employed in any application where it is desirable to mount a chair or seat for sidewise movement to different operative positions. The aim of the appended claims, therefore, is to cover all such changes, modifications and applications as fall within the true spirit and scope of the invention.
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Adjustable device to support a chair on a boat seat enabling the chair to be moved sidewise and locked either in a center position or selected offcenter positions on both sides. A wheeled carriage, with bolts connecting it to a swivelable chair, is movable from side to side along a floor plate in an elongated body which is fastened lengthwise by clamps on a boat seat bench or thwart. A manually movable spring-loaded latch pin mounted on the carriage is selectively engageable in any one of a plurality of apertures in the floor plate to lock the carriage in a center position or a selected offcenter position. The clamps are adjustable to accommodate seat benches of different vertical thicknesses and different fore-and-aft depths. A concealed space is provided within the lower part of the body for threaded clamp adjustment members.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. non-provisional application Ser. No. 10/596,984, filed May 8, 2007, which is the national stage entry of international application serial no. PCT/GB05/03552, filed Sep. 14, 2005, which claims priority to United Kingdom application serial no. 0420468.1, filed Sep. 14, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a vehicle glazing panel cut out technique.
[0004] 2. State of the Art
[0005] Vehicle glazing panels such as vehicle windscreens (windshields) are typically bonded in supporting frames by adhesive bonding material such as polyurethane, applied in a continuous bead about the periphery of the glazing panel and frame.
[0006] Wire cutting techniques have been previously proposed and used to effect glazing panel removal (for replacement or otherwise). Exemplary techniques are disclosed in, for example, EP-A-0093283, Canadian Patent Specification 2034221, U.S. Pat. No. 6,616,800, German Patent 4012207 and PCT Publications WO86/07017 and WO98/58779.
[0007] An improved technique and apparatus has now been devised.
SUMMARY OF THE INVENTION
[0008] According to a first aspect, the present invention provides a winder unit for use with a cutting wire in cutting out a vehicle glazing panel, the unit having:
mounting means for mounting the unit; first and second winder spools for winding cutting wire; and, at least one wire wrap around guide element spaced from the winder spools and/or the mounting means.
[0012] The wrap around guide element is preferably positioned to the side of a respective proximal winder spool.
[0013] The wrap around guide element preferably comprises a guide wheel or pulley rotatably mounted with respect to the unit. Preferably, the winder spools are arranged in side by side arrangement and a respective guide wheel or pulley is positioned outwardly of each respective winder spools. The guide wheel is preferably rotatably mounted relative to the unit. The guide wheels or pulleys are all preferably in the same plane, defined by the position of the wire. It is preferred that at least one of the winder spools includes a ratchet arrangement enabling in one or other direction to be inhibited. Beneficially, the ratchet is releasable to permit rotation in the inhibited direction. The mounting means desirably comprises on or more suction mounts. In one embodiment the unit may include four guide wheels or pulleys, to guide the wire, the guide wheels or pulleys being provided substantially at notional corners of a polygon.
[0014] The unit may be used with a wire to remove a glazing panel. Typically ends of the wire cross over and are connected to respective ones of the winding spools.
[0015] In certain techniques and embodiments the winder unit may beneficially be used in combination with a guide arrangement.
[0016] According to a further aspect, the invention provides a method of cut out of a vehicle glazing panel bonded in a frame by means of interposed bonding material, the method comprising:
setting a wire winder unit on the windscreen, the winder unit including a plurality of winder spools and at least one wire wrap around guide element positioned proximate a corner of the glazing panel; setting a wire guide arrangement on the windscreen spaced from the wire winder unit, the wire guide arrangement including respective wire wrap around guide elements positioned proximate respective corners of the glazing panel; looping a cutting wire about the periphery of the glazing panel and inserting first and second ends of the wire through the bonding material; winding the wire from opposed ends by means of the winder spools.
[0021] It is preferred that the set position of the wire winder unit and the wire guide arrangement relative to the glazing panel remains substantially fixed throughout the cut out procedure. There is therefore no requirement to necessarily reposition the apparatus during the procedure.
[0022] Beneficially, the winder spools are spaced and the opposed end portions of the cutting wire are wound around respective spools, such that a wire crossover portion is created adjacent the winder spools.
[0023] The wire winder unit and wire guide arrangement are preferably set on the glazing panel internally of the vehicle, the cutting wire desirably being looped around the periphery of the glazing panel externally of the vehicle.
[0024] It is preferred that the one or more wrap around guide elements comprise rotatably mounted guide wheels.
[0025] In a preferred embodiment, the wire guide arrangement includes a mounting arrangement comprising one or more suction mounts.
[0026] In a preferred embodiment, the wire winder unit includes a mounting arrangement comprising one or more suction mounts.
[0027] Beneficially, in set up, the cutting wire is inserted to pass through the bonding material at a position proximate a corner of the glazing panel, more preferably at a position to the same side of the glazing panel as the wire winder unit, more preferably still, at a position substantially directly below the wire winder unit.
[0028] It is preferred that the wire wrap around guide elements of the guide arrangement are positioned to the same side of the glazing panel.
[0029] In a preferred technique, at set up, a longer length of cutting wire extends around the wrap around guide elements of the guide arrangement and is wound on a first winding spool of the winder unit, a shorter length of cutting wire extending around a wrap around guide element of the winder unit and being wound on a second winder spool of the winder unit. The wire beneficially defines a cross over point proximate the winder spools. It is preferred that, the spool connected to the shorter length of wire is first wound in to effect a first cut phase; the spool connected to the longer wire length being subsequently wound in.
[0030] Beneficially, during the procedure a ratchet of one of the spools is released facilitating slackening or more preferably unwinding (reverse winding) of a previously wound portion of the cutting wire.
[0031] The guide arrangement preferably includes a mount and a pair of positioning limbs extending from the mount at an apex defined by the proximal ends of the limbs, each said limb carrying at its distal end a respective wrap around guide element for the cutting wire. Desirably, the wrap around guide elements comprise guide wheels rotatably mounted to the respective limbs. Beneficially, the limbs are pivotally connected to the mount such that the angle between the limbs can be varied. The limbs are preferably pivotally connected to the mount such that the limbs can pivot in two mutually perpendicular axes. In a preferred embodiment, the pivotal mount comprises a ball and socket type connection. It is preferred that the apex mount comprises a suction mount.
[0032] It is preferred that one or both (preferably both) limbs is provided with a further mount intermediate the opposed ends of the limb. Desirably, the further mount comprises a suction mount. The further mount is preferably adjustable to be secured at various positions along the length of the limb. Alternatively or additionally, the further mount is adjustable with respect to its angular orientation about the longitudinal axis of the limb. It is preferred that the further mount is adjustable to the position of the mount below the limb.
[0033] The winder unit preferably comprises:
mounting means for mounting the unit; first and second winder spools for winding cutting wire; and, at least one wire wrap around guide element positioned away from the mounting means.
[0037] Beneficially, the wrap around guide element comprises a guide wheel rotatably mounted with respect to the unit. Desirably, the mounting means comprises on or more (preferably a pair of) suction mounts.
[0038] According to a further aspect, the present invention provides apparatus for use in cutting out a vehicle glazing panel using cutting wire, the apparatus comprising:
a winder unit comprising:
mounting means for mounting the winder unit; first and second winder spools for winding the cutting wire; and, at least one wire wrap around guide element positioned away from the mounting means; and,
a guide arrangement including mounting means for mounting the guide arrangement and a pair of positioning limbs extending from the mount at an apex defined by the proximal ends of the limbs, each said limb carrying at its distal end a respective wrap around guide element for the cutting wire.
[0044] Preferred features of the apparatus are as described and exemplified herein.
[0045] The invention will now be further described in a specific embodiment by way of example only and with reference to the accompanying drawings, in which;
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIG. 1 is a schematic plan view of a winder unit of an exemplary cut out system in accordance with the invention;
[0047] FIG. 2 is a schematic representation of a guide arrangement for use with a winder unit in accordance with an exemplary cut out system of the invention;
[0048] FIGS. 3 a and 3 b are detailed views of a parts of the guide arrangement of FIG. 2 ;
[0049] FIGS. 4 to 8 are schematic representations in sequence of a cut out technique in accordance with the invention;
[0050] FIGS. 9 to 11 are schematic representations in sequence of an alternative technique in accordance with the invention;
[0051] FIG. 12 is a schematic representation of a further technique in accordance with the invention; and
[0052] FIGS. 13 and 14 are schematic representations of a further alternative technique in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] Referring to the drawings, and initially to FIGS. 1 to 3 , there is shown a cut out system particularly for use in cut out of bonded vehicle glazing panels such as windscreens. The cut out system comprises a winder unit 1 and a guide arrangement 2 . A flexible cutting wire is looped around the outside of a windscreen glazing panel to lie peripherally adjacent the bonding bead (typically a polyurethane bonding bead) which is sandwiched between the glazing panel and the support frame of the vehicle. Opposed ends of the cutting wire are fed through a pierced channel made through the bonding bead as will be described in detail and the free ends are then each wound around a separate winder spool 4 , 5 of the winder unit. As will be described the long end of the wire is passed around the guide pulley wheels 6 , 7 of the guide arrangement 2 and a first one 8 of the guide pulleys of the winder unit 1 ; the shorter end of the cutting wire being passed around the other of the guide pulleys 9 of the winder unit.
[0054] The winder unit 1 comprises a pair of releasable suction cup mounts 10 , 11 enabling the winder unit to be releasably secured to the windscreen. The suction cup mounts comprise a rigid plastics cup 12 and underlaying flexible rubber skirt membrane 13 . Respective actuation/release levers 14 enable consistent suction to be applied and released. Such suction mounts are commonly employed in windscreen replacement and repair technology. The suction cup mounts 10 , 11 are pivotably/tiltably mounted to the support bracket 15 of the winder unit to ensure that both mounts 10 , 11 can locate in good engagement with the windscreen despite the curvature of the windscreen. The main body of the support bracket 15 carries a pair of underslung winding spools 4 , 5 in side by side relationship. The spools are connected to axial winding shafts which are supported in bearings 16 , 17 provided on the winder unit. The spools 4 , 5 are driven axially rotationally either manually via a hand winder or by means of a mechanical actuator such as a motorised winding or winching tool. Drive bosses 18 are provided with female sockets 19 (square bores) for receiving the male driving tool. Positioned outwardly of the winding spools are respective wire guide pulley wheels 8 , 9 of low friction plastics material. The pulley wheels are mounted to be rotatable about respective rotational axes. The guide pulleys rotate as the cutting wire is drawn tangentially across the pulleys as will be described. The winder spools 4 , 5 are held to rotate in one direction only (each in opposite senses) by respective ratchet mechanisms. Each mechanism includes ratchet override permitting prior tightened wire to be slackened, or unwound (reverse wound).
[0055] The guide arrangement 2 comprises an apex suction cup mount 20 from which extends angularly spaced arms 21 , 22 each of which carry at their respective distal ends a respective distal guide pulley wheel 6 , 7 . The distal guide pulley wheels 6 , 7 are manufactured of low friction plastics material and mounted rotatably to the distal ends of the arms on respective support bosses 23 , 24 . each pulley wheel includes a peripheral channel 25 within which the cutting wire locates. Each arm 21 , 22 is provided with a respective distal suction cup mount 26 , 27 . The distal suction cup mounts 26 , 27 are slidable along the respective arms 21 , 22 and provided with securing clamps 28 actuated by a turn handle 29 to secure the respective distal suction cup mount at the desired position along the length of the respective arm. The securing clamps also permit angular rotation of the distal suction cups about the circumferential outer surface of the rod (arrow A in FIGS. 2 and 3 a ) comprising the respective arm. The depth of the suction cup mounts below the respective arms is also adjustable (arrow B in FIGS. 2 and 3 a ) by means of the suction cup mount including an upstanding post 31 about which the clamp 28 relatively slides and secures by means of a grub screw 30 . The suction cup mount 26 , 27 can also pivot about the upstanding support post 31 (arrow C in FIG. 3 a ). The proximal ends of the arms are mounted to the apex suction mount 20 by means of respective spherical surface profile bosses 35 about which part spherical annular bushed bearings 37 are mounted. These mountings permit the angle between the arms to be adjusted (arrow D in FIG. 2 ) to suit the configuration and size of the subject windscreen. Also the angle between the arm axis and the surface of the windscreen can be varied to suit the curvature of the windscreen (arrow E in FIG. 3 b ). The arrangement of the guide system as described ensures that the distal guide pulley wheels 6 , 7 can be accurately positioned in close proximity to the corners of the windscreen, and that the distal suction cup mounts 28 can be conveniently located to provide secure support proximate the distal pulley wheels 6 , 7 . Because the arms 21 , 22 are both mounted to the apex suction cup mount 20 the whole guide arrangement is securely held to the windscreen the arms taking up the considerable bracing forces exerted by the cutting wire in tension. In view of the large forces generated in the wire during winding, it is important that the guide arrangement is sufficiently securely held secured to the windscreen and of sufficient structural integrity.
[0056] Referring to FIGS. 4 to 8 in which operation of the system to cut out an exemplary body such as a vehicle windscreen is described. The present technique enables the positioning of the system apparatus to achieve cut out with little or no subsequent re-positioning of the system apparatus. The set up is therefore an important phase of the technique.
[0057] The guide arrangement 2 is initially attached via the suction cup mounts 20 , 28 to the inside of the windscreen as shown in FIG. 4 . The aim is to position the pulley wheels 6 , 7 as far into the upper and lower corners of one side of the windscreen as possible, with as little separation between the glass and the pulley wheel as possible. Usually the guide arrangement pulley wheels 6 , 7 are positioned to the non-driver side of the vehicle. In the right hand drive embodiment shown the guide arrangement pulley wheels 6 , 7 are positioned in the upper and lower left hand corners of the windscreen. The suction pads are positioned with this consideration and the adjustable clamps used to fine tune the positioning.
[0058] The winder unit 1 is secured to the underside of the windscreen to the opposite side of the windscreen, along the top edge with the pulleys in side by side relationship such that one of the pulley wheels (pulley wheel 9 ) is positioned as far into the top corner as possible. This arrangement is shown in FIG. 5 .
[0059] The cutting wire preferred for use is generally square in cross section as is known for use in other modalities of windscreen removal. With the winder unit and guide arrangement in position as described, the cutting wire is looped around the outside of the windscreen to lie peripherally adjacent the bonding bead which is sandwiched between the glazing panel and the support frame of the vehicle. Opposed ends of the cutting wire are fed through a pierced channel made through the bonding bead in the corner of the windscreen (x) below the position of the winder unit 1 . A longer end length 40 of the wire is pulled through to the interior of the vehicle and passed around the two pulley wheels 6 , 7 of the guide arrangement and connected for winding to the winder spool 4 of the winder unit closest to the corner in which the winder unit is mounted. The shorter end length 41 of the wire is fed adjacent the inside of the windscreen and passed around the pulley wheel 9 of the winder unit closest to the corner in which the winder unit is mounted before being connected for winding to the other winder spool 5 (the ends of the wire therefore cross in order to connect to the respective winder spools 4 , 5 of the winder unit. The situation as described is shown in FIG. 6 . This concludes the set up phase of the technique.
[0060] The first phase in the cutting procedure is to wind the wire shorter end length 41 by winding in on the left hand winding spool 5 ; this causes the cut line to move upwardly through the bonding bead and around the upper corner of the windscreen proximate to the winder unit, passing along a short portion of the upper edge of the windscreen. The shorter end length takes up sequential positions as shown by the dashed line in FIG. 7 . At this point the ratchet is released and the spool is rewound a little until the wire becomes slightly slack. The reason for this is described later in the procedure.
[0061] Operation of the other winder spool 4 of the winder unit 1 effects a cut along the bottom edge of the windscreen up the side of the windscreen proximate the guide arrangement and along the top edge of the windscreen. The sequential interior wire length positions are shown in dashed line in FIG. 8 . Initially, after the wire has come clear of the lower guide pulley wheel, the ratchet previously released from the first operated winder spool is reactivated. Continued operation of the second winder spool 4 moves the cut line around the top corner of the windscreen and along the upper edge of the windscreen (from left to right as shown in the drawings) crossing over the shorter wire length portion above the winder unit to effect complete cut out of the windscreen.
[0062] As described above the ratchet of the first used winder spool 5 is released following the first, short length cut. This is because in the second cut stage in which the longer length wire is wound in and in which the cut line moves from right to left along the lower edge of the windscreen in the drawings, the thicker excess bonding material that is likely to be encountered in this region of the windscreen will be tough to cut through, increasing the forces transmitted through the system. By deactivating the ratchet of the first winder spool 5 , the wire will slip/slide at this point, feeding back off the first spool to an extent resulting in a cutting slicing action that aids the cut effectiveness at this point. When the tougher cut has been accomplished, the wire will again follow the path of least resistance and resume cutting normally (and the wire will stop back feeding off the first winder spool). This system tweak reduces the likelihood of the wire breaking due to excessive tension. The ratchet can then be reapplied. The point at which the ratchet should be reapplied and deactivated typically comes down to operator skill, experience and judgement.
[0063] In the technique shown in FIGS. 9 and 10 , the glazing panel is removed using a wire 41 and the winder unit 1 only (no additional guide, such as guide 2 is required). In this technique the winder unit is initially secured to the steering wheel side of the glazing panel, positioned above the steering wheel as shown in FIG. 9 . With the winder unit and guide arrangement in position as described, the cutting wire is looped around the outside of the windscreen to lie peripherally adjacent the bonding bead which is sandwiched between the glazing panel and the support frame of the vehicle. Opposed ends of the cutting wire are fed through a pierced channel made through the bonding bead in the corner of the windscreen (x) below the position of the winder unit 1 .
[0064] A length 41 of the wire is pulled through to the interior of the vehicle and passed around pulley wheel 9 of the winder unit and connected for winding to the winder spool 5 of the winder unit. A free end length of wire 47 is pulled through, being of length sufficient to reach the upper left hand corner of the glazing panel. Winder spool 5 is then operated to cause the wire length 41 to cut through the bonding bead upwardly along the side of the windscreen, until the cut line has passed around the upper right hand corner of the screen. At this juncture, the unit 1 is removed from the screen and repositioned on the glazing panel in the upper left hand corner as shown in FIG. 10 . Prior to repositioning the unit 1 , the ratchet of winder spool 5 is released to permit the wire to be wound out from the spool as it is moved across the glazing panel to be repositioned. The ratchet is subsequently re-engaged and spool 5 once again operated to wind in the wire from the position shown in FIG. 10 until it reaches the position shown in the dashed line in FIG. 10 .
[0065] Next the unit 1 is moved around the corner of the glazing panel and through substantially a right angle, to the position shown in FIG. 11 , where it is secured to the glazing panel. In order to enable this the ratchet of spool 5 is again released and subsequently re-engaged when the unit is in position as shown in FIG. 11 . The end of the free length of wire 47 is then wound around pulley 8 and connected to winder spool 4 and the spools 4 and 5 operated either sequentially (or simultaneously) to complete the cut. As shown in FIG. 11 . The lengths of wire cross at Z in order to complete the cut. The presence of the pulleys 8 , 9 spaced outwardly from the respective spools 4 , 5 aids in operation of the winder unit during the cutting process.
[0066] In FIG. 12 there is shown a modified winder unit 1 having additional wrap around pulleys 108 , 109 , positioned to provide a respective pulley at four respective corners. The unit is mounted as shown in FIG. 12 approximately central to the glazing panel. The wire is looped around the exterior of the panel with two ends of the wire passing through a channel at X into the interior of the vehicle. The free ends are secured to respective spools 4 , 5 with a wire crossover at 115 . Operation of the spools 4 , 5 to wind in respective lengths of wire from the position shown results in cut through being effected about the entire periphery of the glazing panel.
[0067] In a modification to this technique the four pulley winder unit is used as shown in FIGS. 13 and 14 . The unit is initially positioned as shown in FIG. 13 , and pulley wheel 4 initially operated to wind the wire around the upper left hand corner of the glazing panel. Subsequently the unit is repositioned to the position shown in FIG. 14 and both winder spools 4 and 5 operated (typically in sequence) to complete the cut through process.
[0068] The present invention provides the benefits of wire cutting systems without over complex system apparatus arrangements or the need to re configure the apparatus significantly following initial set up. The technique can be used by operators of relatively little experience or physical strength following an initial set up routine of minimal complexity.
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A winder unit is disclosed for use with a cutting wire in cutting out a vehicle glazing panel. The unit is capable of being mounded to the glazing panel and includes first and second winder spools for winding cutting wire. At least one wire wrap around guide element (typically a pulley) is positioned away from the mounting means. The unit may be used in various techniques either alone or with an auxiliary guide arrangement.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to portable pneumatic tools and, more particularly, to compression riveters, used to install solid rivets primarily but not limited to the aerospace industry.
[0003] 2. Description of the Related Art
[0004] Portable pneumatic compression riveters are used to install solid rivets to join parts together. They consist of a valve assembly, cylinder assembly with at least one compression chamber and a head assembly consisting of an alligator style set of jaws or a c-yoke style jaw set. An air line with approximately 90 psi compressed air is connected to the valve. The valve is manually actuated by means of a lever allowing compressed air to enter the cylinder assembly. Inside the cylinder, a piston with a seal and a wedge attached to the front is driven forward by the compressed air. The wedge is driven between a set of bearings mounted within the jaws of the rivet head assembly. The wedge forces the pivoting jaw to pivot about a center pin resulting in a squeezing action out on the end of the pivoting jaw as it closes with the fixed jaw. This squeezing action is the means to upset the rivet to join parts together.
[0005] To function most effectively, the valve assembly and cylinder assembly must not leak air. The cylinder material must be both capable of handling the air pressure required to operate the tool and hard enough to resist the wear of the piston. The wedge must be properly aligned with the bearings mounted in the rivet head assembly and capable of handling the resultant forces from upsetting the rivet. A needle roller bearing is typically used with the pivot pin from which the pivoting jaw pivots about. Crushing these needle rollers has long been a limiting factor for this type of tool.
[0006] Another shortcoming of the portable pneumatic compression riveters produced today is the potential for catastrophic failure of the pivoting jaw which can lead to injury or damage to the work being assembled when the forward portion of the pivoting jaw reaches its fatigue limit and breaks off from the attached portion at or around the pivot pin area.
[0007] One of the major reasons for these shortcomings is the need to make the portable pneumatic compression riveter as light as possible for ergonomic reasons. An improved portable pneumatic compression riveter which addresses these problems and shortcomings of earlier work in this field would be an important technological advance.
[0008] It is an object of the invention to provide a portable pneumatic compression riveter which addresses some of the problems and shortcomings of the prior art.
[0009] Another object of invention is to provide such a portable pneumatic compression riveter which addresses cylinder, piston and seal wear issues while contributing to a lighter and more reliable seal design.
[0010] Another object of the invention is to provide such a portable pneumatic compression riveter which allows for a greater misalignment between the wedge and the bearings in the rivet head assembly and further contributes to reducing the weight of the tool.
[0011] Another object of the invention is to provide such a portable pneumatic compression riveter which addresses the problem of crushed needle roller bearings at the pivot pin by utilizing a hardened steel sleeve in place of the needle roller bearing. This further contributes to a lighter, more reliable and compact tool.
[0012] Another object of the invention is to provide such a portable pneumatic compression riveter which reduces the chance of catastrophic failure of the pivoting jaw thus reducing the chance of injury or damage to the work being assembled.
[0013] Another object of the invention is to provide such a portable pneumatic compression riveter which utilizes a composite valve body to further reduce the weight of the tool. How these objects are accomplished will become apparent from the following descriptions and from the drawings.
SUMMARY OF THE INVENTION
[0014] Portable pneumatic compression riveters consist of a valve assembly, cylinder assembly with at least one chamber and a head assembly consisting of an alligator style set of jaws or a c-yoke style jaw set. An air line is connected to the valve assembly. The valve is manually actuated by means of a lever allowing air to flow into the cylinder. In the improvement the valve body is of a composite material with an integrated handle improving ergonomics and significantly reducing the weight. The bulkheads separating the chambers in the cylinder assembly are also made of a composite material that seals each chamber with an o-ring and quad-ring. The pistons are also made of a composite material and used with one or more u-rings to seal the piston—cylinder assembly. Use of the u-rings allows the use of an aluminum cylinder with the composite pistons taking most of the wear. The u-rings allow for a significantly larger amount of wear than does a piston with an o-ring; this contributes significantly to extend the service life interval. Further, since composite pistons are used, the cylinder can be made of aluminum without the benefit of hard anodize applied to the interior of the cylinder or using a steel cylinder to address cylinder wear and seal problems.
[0015] In another aspect of the invention, the wedge is pinned within a clevis that is mounted to the face of the piston. The wedge, driven forward by the compressed air behind the piston, is forced between a set of bearings causing the pivoting jaw to pivot about the center pin resulting in a squeezing action out on the end of the pivoting jaw as it closes with the fixed jaw. In the improvement, the wedge has angled flats on the nose which allow the wedge to self align as it moves forward rather than bind in the rivet head assembly. The wedge's construction is such that it is pocket milled on both sides creating an I-beam cross section which contributes to a lighter tool.
[0016] In another aspect of the invention, an improvement is made by utilizing a hardened steel sleeve, instead of a needle roller bearing at the pivot pin, to eliminate the problems with crushed needle rollers and also contribute to a lighter, more reliable and compact tool.
[0017] In yet another embodiment of the invention, an improvement is made by adding a hollow recess to the pivoting jaw just above and behind the pivot pin with the purpose of allowing a fatigue crack to propagate into the hollow recess thus preventing a catastrophic failure of the forward portion of the pivoting jaw from becoming a projectile that could cause injury to the operator or damage to the work being assembled.
[0018] Further details of the invention are set forth in the following detailed descriptions and in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a representative side view of an exemplary portable pneumatic compression riveter.
[0020] FIG. 2 is a top elevation view of an exemplary portable pneumatic compression riveter.
[0021] FIG. 3 is a fragmentary sectional view taken along viewing plane 3 - 3 of FIG. 2 of the portable pneumatic compression riveter prior to the valve's lever being actuated.
[0022] FIG. 4 is a fragmentary sectional view taken along viewing plane 3 - 3 of FIG. 2 of the portable pneumatic compression riveter after the valve's lever is actuated.
[0023] FIG. 5 is an exploded assembly view of the new composite valve body with the integrated handle.
[0024] FIG. 6 is a fragmentary section view taken along viewing plane 3 - 3 of FIG. 2 of the portable pneumatic compression riveter showing the new composite pistons with u-ring seals.
[0025] FIG. 7 is a fragmentary sectional view taken along viewing plane 3 - 3 of FIG. 2 of the portable pneumatic compression riveter of the wedge driven between the bearing sets in the rivet head assembly.
[0026] FIG. 8 is a fragmentary sectional view taken along viewing plane 3 - 3 of FIG. 2 of the portable pneumatic compression riveter showing the pin—clevis—wedge subassembly showing the vertical float of the wedge inside the rivet head assembly.
[0027] FIG. 9 is a top elevation fragmentary sectional view taken along viewing plane 9 - 9 of FIG. 8 of the pin—clevis—wedge subassembly showing the horizontal float of the wedge inside the rivet head assembly.
[0028] FIG. 10 is a prospective view of the wedge.
[0029] FIG. 11 is a sectional view taken along viewing plane 11 - 11 of FIG. 8 showing the cross section of the wedge.
[0030] FIG. 12 is a fragmentary sectional view taken along viewing plane 3 - 3 of FIG. 2 of the portable pneumatic compression riveter showing the pivot pin area of the rivet head assembly.
[0031] FIG. 13 is a fragmentary sectional view taken along viewing plane 3 - 3 of FIG. 2 of the portable pneumatic compression riveter showing the pivoting jaw with its hollow recess inside the rivet head assembly.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] Referring first to FIGS. 1, 2 , 3 and 4 an exemplary portable pneumatic compression riveter is depicted which includes a valve assembly 14 , cylinder assembly 16 with more than one chamber (3 chambers in this representation identified here as chambers 1 , 2 and 3 ), and a rivet head assembly 17 . FIGS. 1, 2 , 3 and 4 show the compression riveter fitted with an al1igator set of jaws 10 . The exemplary portable pneumatic compression riveter includes the preferred embodiments disclosed in this document. FIG. 3 shows the compression riveter prior to the lever 15 on the valve assembly 14 being actuated with the alligator jaw set 10 open. FIG. 4 shows the compression riveter with the lever 15 on the valve assembly 14 actuated and the alligator jaw set 10 closed. When the lever 15 is released the alligator jaw set 10 opens and the compression riveter resets as shown in FIG. 3 .
[0033] Additionally, FIG. 5 shows the composite valve body 12 with the integrated handle. The composite valve body 12 is made of a composite material and houses the valve sleeve assembly 21 . The lever 15 is used to actuate the valve sleeve assembly 21 inside the composite valve body 12 .
[0034] Referring additionally to FIGS. 3, 4 and 6 the unidirectional composite pistons 7 and bi-directional composite piston 8 each have u-ring seals 9 with the bi-directional piston having two u-ring seals 9 installed opposing each other. When the lever 15 is actuated, compressed air enters the first and successive chambers (chambers 1 , 2 and 3 in this representation) in the cylinder assembly 16 building pressure behind the stationary composite bulkheads 6 sealed with o-rings 5 and quad rings 11 . The pistons 7 and 8 are driven forward forcing the wedge 25 pinned in the clevis 27 attached to the lead piston 7 into the rivet head assembly 17 . As a result, the pistons 7 and 8 rub against the cylinder wall 18 . The composite pistons 7 and 8 act as traditional wear rings and protect the cylinder wall 18 from excessive damage. The u-ring seals 9 allow for as much as 0.060 wear, in this example, to the piston's 7 and 8 outside diameter while still maintaining a full seal. This greatly exceeds the amount of dimensional change that a conventional o-ring—piston—cylinder arrangement in this type of tool can have and maintain its seal.
[0035] Refer to FIGS. 7, 8 and 9 where the wedge 25 is driven between the bearings 28 and 29 on the rivet head assembly 17 . FIG. 8 shows the hole 23 in the wedge 25 is larger than the pin 30 diameter in the clevis 27 allowing “vertical float” 38 to compensate for any misalignment of the wedge 25 with the bearings 28 and 29 positioned in the rivet head assembly 17 . Refer additionally to FIGS. 8 and 9 where the width of the back of the wedge 25 at its attach point to the clevis 27 where the pin 30 attaches them is narrower than the clevis' 27 width. This allows for “horizontal float” 39 to compensate for any misalignment of the wedge with the rivet head assembly 17 . Referring also to FIG. 10 an angled flat 40 on the front of the wedge 25 allows the wedge 25 to self align without binding as it moves forward into the rivet head assembly 17 . Additionally, refer to FIGS. 8 and 11 where a cross section of the wedge 25 is presented. This light but rigid wedge design contributes to a significant reduction in the weight of the wedge 25 and contributes to a lighter compression riveter.
[0036] FIG. 12 shows a sectional view of the pivot area 33 of the rivet head assembly 17 . In the center is a hardened steel sleeve 35 that slip fits into the pivoting jaw 31 and is joined together with the fixed jaw 32 with a slip fit pivot pin 34 . The hardened steel sleeve 35 avoids the problems encountered with a needle roller bearing in this application and contributes to a lighter more reliable and compact compression riveter.
[0037] FIG. 13 shows another embodiment of the improvement to the portable pneumatic compression riveter where the pivoting jaw 31 has a hollow recess 36 behind the pivot pin 34 . The hollow recess 36 provides a safe zone to arrest a crack in the pivoting jaw 31 propagating from the pivot area 33 . This hollow recess 36 helps prevent a catastrophic failure caused by a crack propagating unchecked from the pivot area 33 allowing the forward portion of the pivoting jaw 31 to become a projectile. The hollow recess 36 also contributes to a lighter tool.
[0038] While the principles of the improvements have been shown and described in connection with preferred embodiments, it is to be understood clearly that such embodiments are by way of example and are not limiting.
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A portable pneumatic compression riveter consists of a valve, air cylinder and rivet head assembly consisting of an alligator style set of jaws or a c-yoke style jaw set that is used to upset solid rivets used primarily, but not limited to, the aerospace industry. Disclosed is a series of improvements that make the tool lighter, more reliable and safer to operate.
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This application is a continuation of application Ser. No. 776,804, filed on Sept. 17, 1985, now abandoned.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a semiconductor device and method of manufacture thereof.
More particularly, the invention relates to a semiconductor device in which one end of a bonding wire whose other end is connected to a bonding pad of a semiconductor element is in good connection to a lead frame and which displays excellent electrical properties in high temperature conditions or in high temperature, high humidity conditions.
(2) Description of the Prior Art
As shown in FIG. 1, in a conventional semiconductor device manufacturing method, a Ni plating layer 2 is formed on the surface of a lead electrode 1 made of copper, etc. and a bonding pad 5 on a semiconductor element 4 and the lead electrode 1 are connected via this Ni plating layer 2 by a bonding wire 3. In the drawing, a resin sealing body 6 and a solder layer 7 are formed via a Ni plating layer 9 on a lead frame 8.
However, with a device in which Ni plating layers 2 and 9 are formed, there are the problems that there is considerable variation in plating quality, that the manufacturing process for effecting plating treatment is complex and that the plating treatment makes manufacturing costs higher, etc. A practice in recent years, therefore, has been to effect direct connection of an aluminium bonding wire 3 onto a lead electrode 1 of copper, etc. without carrying out plating treatment.
However, in testing of semiconductor devices with aluminium bonding wires 3 connected directly to lead electrodes 1 of copper, etc. in long-time shelf tests in high temperature conditions (150° C., 175° C.) or in high temperature (about 80° C.), high humidity (about 90%) conditions, there has been found to be a problem of reduced reliability because of opening at the bond interface between bonding wires 3 and lead electrodes 1.
A technique for resolving this problem in which bonding wire spanning between bonding wire constituted by copper wire and a lead frame made of copper is effected by selectively activating the bonding region is disclosed in Japanese Patent Application No. 55-88318. However, in this technique there are the problems that oxide forming on the bonding wire causes bond faults and that it is difficult to form a set ball at the bonding wire end portion. Further, working characteristics are poor because the bonding area has to the activated in each bonding process.
Japanese Patent Application No. 57-51237 discloses a bonding process technique in which a ball of required shape is formed and bonding oxidation is prevented by introducing a capillary end portion leading out from a bonding wire under a cover where a reducing atmosphere is maintained. However, this technique requires a complex structure including a cover for maintaining a reducing atmosphere and when the bonding process is effected at a process speed of one second or less there is the problem that maintenance and control are troublesome since faults occur easily. There is also the problem that it is not possible to effect highly reliable bonding between bonding wire constituted by copper wire and a lead frame made of copper since it is not possible to prevent oxidation on the lead frame side where an external lead is formed.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a highly reliable semiconductor device which displays excellent electrical characteristics in high temperature conditions or in high temperature, high humidity conditions and a manufacturing method which makes possible the easy production of such a semiconductor device.
The invention is a semiconductor device and manufacturing method thereof which displays excellent electrical characteristics in high temperature conditions or in high temperature, high humidity conditions thanks to connection of an end portion of aluminium bonding wire to lead electrode of copper or copper alloy in a manner such that the reaction layer thickness is made 0.2 (micron) or more.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention together with a ready appreciation of other objects and many of the attendant advantages thereof may be had from the following description considered with reference to the attached drawings, in which like reference numbers indicate like parts and in which:
FIG. 1 is a cross-section of a semiconductor device manufactured by a conventional method;
FIGS. 2-5 and FIG. 7 are explanatory drawings illustrating the method of the invention in the order of steps therein;
FIG. 6 is a graph showing the relation between time and temperature for reaction layer formation: and
FIGS. 8-10 are explanatory drawings showing lead electrode and bonding wire connection states.
DESCRIPTION OF PREFERRED EMBODIMENTS
The method of the invention and semiconductors in embodiments thereof will now be described with reference to the attached drawings. First, as shown in FIG. 2, a semiconductor element 22 is mounted on a mount portion of a lead frame 20 made of copper or copper alloy via a solder layer 21. The copper alloy employed here may be phosphor bronze or be another copper alloy containing iron.
Next, as shown in FIG. 3, one end of 200 (microns) of bonding wire 23 made of 99.99% pure aluminium is fused to a bonding pad 24 on the semiconductor element 22 by ultrasonic bonding process. Then, the other end of the bonding wire 23 is similarly fused by ultrasonic bonding process to a lead electrode 25 of the lead frame 20. Like the lead frame 20, the lead electrode 25 also is formed by copper or a copper alloy.
Next, heat treatment is effected to make the thickness of the aluminium and copper or copper alloy reaction layer formed at the portion where the bonding wire 23 and lead electrode 25 are fused together 0.2 (micron) or more.
As shown in FIG. 4, in order to effect heat treatment on the lead electrode 25, heaters 40 and 42 with a temperature of about 600° C. hold the lead electrode 25 from above and below and transfer heat at a location where the lead frame 20 has been advanced to position I. Successive shifts of the lead frame 20 from the left towards the right as seen in FIG. 4 are effected about once every 1.2-1.3 second. That is, one-time contact of the heater 40 gives insufficient transfer of heat for formation of a reaction layer of 0.2 (micron) or more and so formation of a reaction layer with a thickness of 0.2 (micron) or more is brought about by the provision of heaters in a number of places combined with shifts of the lead frame 20. FIG. 4 illustrates the case where there are two places, I and II. In this embodiment, the heater contact time is about 0.5 seconds and heaters are provided in five places. FIG. 5 shows a cross-section of the state of FIG. 4 seen from the side. In FIG. 5, the lead frame 20 is set on a pedestal 50, which is provided with a blow hole 52 for a mixed gas containing nitrogen for cooling the lead frame 20. This is in order to prevent melting of the solder layer 21 due to the lead frame 20 being heated by the heaters 40 and 42 as well as the lead electrode 25. An air atmosphere may be used for the heat treatment but since the copper or copper alloy frame is oxidized as heating proceeds it is preferable to have a non-oxidizing atmosphere or a reducing atmosphere. In this embodiment, use is made of a mixed gas containing 90% N 2 and 10% H 2 . The non-oxidizing gas employed here may be inert gas, be reducing gas or be mixed gas thereof. For example, the inert gas may be argon or helium and the reducing gas may be hydrogen. FIG. 6 shows the relation between time and temperature for reaction layer fomation. In this embodiment, the temperature of the bonding portion 26 is set at 400°-450° C. and heating treatment is effected to give a total amount of intermittent heating time of about 5 seconds. Heating is not limited to being intermittent heating, it being simply necessary to have a total heating time of about 5 seconds.
Although description was given above with reference to a heating method in which elements are held between heaters, another method that may be employed is to effect heating by several tens of seconds to several minutes passage of the lead frame through a hydrogen oven or a nitrogen oven at a temperature of 350°-400° C. Other methods include a method in which the lead electrode 25, leaving out the bonding portion 26, is heated with a burner torch, a method in which the lead electrode 25 is heated using a resistance welder and a method in which the lead electrode 25 is heated using a laser. Further, there is no restriction to these methods but any other method apart from these may be used as long as it permits heating with the temperature and time controlled in the range of the upper portion including the shaded portion of FIG. 6.
From the constitutional diagram and sectional examination of the abovenoted reaction layer, the composition of the reaction layer is inferred to be Al 2 Cu, AlCu.
Subsequently, as shown in FIG. 7, mold treatment is effected to give a semiconductor device 30 in which the semiconductor element 22, lead frame 20, bonding wire 23 and lead electrode 25, etc. are sealed as an integral unit in resin sealing body 27.
Since connection of the bonding wire 23 and lead electrode 25 is effected with formation of a reaction layer that is 0.2 (micron) or more in the semiconductor device 30 thus produced, it is made possible to prevent opening faults in the bonding wire 23 and lead electrode 25 bond portion even in high temperature conditions or high temperature, high humidity conditions, and as a result there is produced a highly reliable semiconductor device 30. Also, the manufacturing process is simplified and manufacturing costs can be reduced since there is no need to effect plating treatment on the lead frame 20 and lead electrode 25.
The reason for making the thickness of the reaction layer formed by the aluminium and copper or copper alloy 0.2 (micron) or more is that, as is made clear from the test examples described below, products that are rejects because of opening faults occur in high temperature conditions or high temperature, high humidity conditions if the thickness is less than 0.2 (micron).
TEST EXAMPLES
As illustrated in FIGS. 2-5 and FIG. 7, semiconductor elements 22 were mounted in a non-oxidizing atmosphere on lead frames 20 of copper or copper alloy on which plating layers had not been formed and then aluminium bonding wires 23 bridging bonding pads 24 of the semiconductor elements 22 and lead electrodes 25 of lead frames 20 were attached by ultrasonic bonding process. Next, mold treatment of these assemblies was effected to give semiconductor devices (Test Products 1). In this case, as illustrated in FIG. 8, no plating layer was formed on the surface of the lead electrodes 25 and there was no reaction layer present between the bonding wires 23 and the lead electrodes 25.
Semiconductor devices constituting Test Products 2 were manufactured by mounting semiconductor elements 22 and bonding bonding wires 23 and lead electrodes in the same way as for Test Products 1 after thorough reduction of the lead frames 20 in a high temperature reducing atmosphere.
Semiconductor devices were produced in the same way as Test Products 2 except that reaction layers 60 were formed between the bonding wires 23 and lead electrodes 25 as shown in FIG. 9 by heat treatment following connection of the bonding wires 23 and lead electrodes 25. In this case, devices with a reaction layer 60 thickness of 0.1 (micron) or less were taken as Test Products 3, devices with 0.2-0.5 (micron) as Test Products 5 and devices with 1-2 (microns) as Test Products 6.
Semiconductor devices produced in the same way as Test Products 2 after preliminary formation of Ni plating layers 70 on the lead frames 20 and lead electrodes 25 as shown in FIG. 10 were taken as Test Products 7.
High temperature shelf tests consisting of 500 hours, 1000 hours, 1500 hours, 2000 hours and 2500 hours or more at 150° C. and 300 hours, 500 hours, 1000 hours and 1500 hours or more at 175° C. were conducted on 20 each of the semiconductor device Test Products 1-7 produced in the abovedescribed manner. Investigation of occurrence of rejects because of opening faults between bonding wires 23 and lead electrodes 25 gave the results noted in the following table.
TABLE__________________________________________________________________________ Temperature at which left 150° C. 175° C. Hours leftSample 500 1000 1500 2000 2500 300 500 1000 >1500__________________________________________________________________________Test 0 0 0 0 0 0 0 0 0 With Ni platingProduct 7 layers With no Ni platingProduct 1 0 0 2 10 20 1 7 20 -- layers and reaction layersProduct 2 0 0 0 3 7 0 0 5 13 With no Ni plating layers and reaction layersProduct 3 0 0 0 1 3 0 0 3 6 Reaction layer <0.1 micronProduct 4 0 0 0 0 0 0 0 0 0 0.2-0.5 micronProduct 5 0 0 0 0 0 0 0 0 0 0.5-1 micronProduct 6 0 0 0 0 0 0 0 0 0 1-2 microns__________________________________________________________________________
As is clear from the above table, the number of rejects occuring because of opening faults becomes smaller as the reaction layers formed by the copper or copper alloy and aluminium is larger and it is seen that when the thickness of the reaction layer is 0.2 (micron) or more high reliability equivalent to that of devices with Ni plating layers in displayed.
Long-term shelf tests at high temperature and high humidity (80° C., 90%) were conducted on the above-described semiconductor device Test Products 1-7 and it was found that there was similarly no occurrence of rejects when the reaction layer thickness was 0.2 (micron) or more. Futher, similar results were obtained in thermal impact tests (-45° C.←→150° C.) and thermal fatique tests too.
As described above, with semiconductor devices and method for their manufacture according to the invention, it is possible to easily produce highly reliable semiconductor devices which display excellent electrical characteristics in high temperature conditions or in high temperature, high humidity conditions.
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This invention concerns a semiconductor device manufacturing method wherein connection is made of the end portion of aluminium bonding wire to a lead electrode of material selected from the group consisting of copper and copper alloy in a manner such that the reaction layer thickness is 0.2 micron or more, thereby resulting in excellent electrical characteristics in high temperature conditions or in high temperature, high humidity conditions.
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[0001] This invention relates to the safe administration of drugs in the hospital environment.
BACKGROUND TO THE INVENTION
[0002] In modern health care and particularly in the hospital environment there a large number of drugs to be administered by a range of techniques including orally, by injection and intravenously. The drugs themselves come in a range of dosage forms and usually require some preparation particularly as dosage rates vary according to patient's condition and also their body weight. With nursing staff working different shifts keeping a record of what has been administered requires care and a certain amount of bookkeeping. The current lack of automation and the mathematical abilities of nurses has produced unacceptable error rates. Indeed, apart from the human cost, several measures have estimated that the world wide cost of errors attributable to incorrect drug administration exceeds a billion dollars. Competence in drug calculations has been a long-standing issue at the undergraduate level in Nursing education and is an important root cause in the problems later observed in the clinical environment. In an Australian study conducted in 2000 19% of final year candidates could not achieve a proficiency level of 50% in a standard Drug Calculation. In this test 36% of students achieved a score of 80% (which was considered an accepted level of proficiency) whilst only 3% achieved a score of 100%.
[0003] A lack of automation has been widely identified as a contributing factor in drug-calculation errors. The benefits of introducing a level of automation are clear and numerous and include: 1) Machines perform multi-step algorithms far more efficiently and accurately 2) A final safety check can be incorporated by linking to electronic pharmacopoeia 3) Analysis of an electronic ADE (Adverse Drug Event) audit trail can lead to incremental improvements in the system 4) An opportunity for this automation to be integrated with new technology associated with emerging medical information systems and/or hand-held devices.
[0004] Some attempts have been made to address this problem. U.S. Pat. No. 4,807,170 discloses a handheld calculator for IV administration. Different screens are used for the different types of calculations which vary according to the input data available.
[0005] U.S. Pat. No. 5,772,635 discloses an infusion system with an integrated drug dosage calculation system.
[0006] U.S. Pat. No. 5,915,971 discloses a tutorial device for teaching nurses the range of calculations that need to be used.
[0007] U.S. Pat. No. 6,167,412 discloses a general handheld calculator for medical use and has a wide range of available functions.
[0008] All of these attempts to address this problem contain the drawback that they rely on a particular interface/mode to be created for a particular problem (one screen interface for each calculation type). This, in turn places a burden on the nurse to first find the correct interface (assuming it even exists in the system) using a certain level of mathematical understanding.
[0009] Despite the obvious advantages of automation there does not currently exist any widespread automation of drug calculations in the clinical setting. This appears to be due to serious usability issues that arise from adopting the current “1-interface 1-calculation” approach.
[0010] It is an object of this invention to provide a convenient error-proof means of calculating the correct dose for any particular drug and patient.
BRIEF DESCRIPTION OF THE INVENTION
[0011] To this end the present invention provides a method of administering a drug to a patient which involves providing an interface for entry of data including one or more of drug identity, dosage rate, prescribed dosage form, concentration and form of drug, and patient body weight, processing the input data using an algorithm which converts the input data into a set of instructions for administering the drug including the amount and time for the first and subsequent administrations, administering the drug and recording the amount and times on the patients record. This invention makes automation of the calculations feasible because it is based on an insight that all drug calculations follow a certain pattern and the resulting innovation is that a single algorithm can be adapted to answer any type of drug calculation that nurses need to perform.
[0012] Performing these calculations from a single interface means that any arithmetic can now be automated thereby becoming more efficient and reliable as well as opening up the possibility of automated checks on any final dosage calculated. This invention has demonstrated this fact with a single interface that can perform almost all the calculations required of nurses.
[0013] The algorithm used in this invention embodies a more uniform way of conceptualizing all the different types of individual calculations that are required of nurses and is in some sense an example of the whole (new algorithm) being greater than the sum of the parts(all the variety of individual calculations).
[0014] The input format is a kind of a “shop window” to the algorithm.
[0015] The technology encompasses a simple calculator interface that can produced as a mass market device with the potential to create additional modules to incorporate toxicology, patient history and database management.
[0016] The technology can (depending on the relevant computing infrastructure) be embodied in a multitude of interfaces. These include (but are not limited to) a standard computer screen, existing hand-held computers (pda, pocket PC, mobile phones) as well as potentially, a custom-made hand-held device dedicated to drug-dosage calculations
[0017] A computer-screen accessible in hospital wards may be used. Networked computers are commonplace in hospitals and provide an ideal location for the interface. Hand-held calculators or a PDA may be useful for hospitals without this computing infrastructure.
[0018] The major point of difference between the method of this invention and other calculators is the use in this invention of a single interface. Without such an interface, a catch-22 situation occurs in any system with a 1-1 correspondence between its interfaces and the calculations it automates. That is, in a system with a small number of interfaces/calculations, any individual interface can be quickly found but the small number of corresponding calculations severely limits its functionality and usefulness. Increase the number of interfaces on the other hand, and the system's usability rapidly diminishes as users are forced to select a relevant one amongst a large array of interfaces (assuming that one even exists). It is this inbuilt limitation that is arguably the reason why conventional calculators are currently not in widespread use in the clinical setting.
[0019] This advantage is derived from the fact that the method of this invention constructs Formulae instead of Selecting Formulae. The method of this invention is able to automate an array of functions from the one interface which is another point of difference in its approach towards the automation of drug calculations. That is, instead of a “black-box” approach embodied in a formulae's selection, a customized formula is constructed directly from the dose's description. The net effect of this is that a human's input is emphasized where it is most needed (in constructing a formulae from a clinical situation) and de-emphasised it where it is least needed (i.e. in the formula's actual evaluation).
DETAILED DESCRIPTION OF THE INVENTION
[0020] A preferred form of the invention is illustrated in the drawings in which:
[0021] FIG. 1 illustrates the generic interface screen and formula used in this invention.
[0022] FIG. 2 illustrates the interface screen used in this invention;
[0023] FIG. 3 shows the screen with an answer to a typical computation;
[0024] FIG. 4 illustrates an interface screen according to another embodiment of this invention.
[0025] With reference to FIG. 1 the formula is derived as follows:
[0026] Let Q={1, . . . , n } index a sequence of facets, Q 1 , Q 2 , . . . , Q n . Each facet can be thought of as representing a particular feature of a system which can be measured in any convenient unit. From these n different facets, we distinguish one, x ε Q which is to correspond to a feature of particular interest. Frequently, the amount of this distinguished facet is dependent on, and occurs in proportion to, the amounts of other, accompanying and in some sense independent facets. Let V index the sequence of these other facets (Hence, V ε Q-{x}). The magnitude of each facet measured can be determined by two components, {q i , q i u } where q i , is a numerical value that describes the amount of the unit q i u —which, although designed to denote a unit, is actually a number that represents a multiple of some assumed base unit (typically this would be a SI unit so that where the unit to be denoted is a “millilitre”, for example, we would have q i u =10 −3 ). The dependence of the amount of the distinguished facet—(q x *q x u ) on the amounts of other selected facets (which is indexed by V) can be stated in a list as follows:
[0000] {{q x ,q x u }←|{q v 1 ,q v 1 u },{q v 2 ,q v 2 u } . . . {q v |ν| ,q v |ν| u }} (1)
[0027] That is, this list states that an amount of q x *q x u of facet Q x occurs in a system where measured amounts of q v 1 *q v 1 u , q v 2 *q v 2 u , . . . , q v |ν| *q v |ν| u of the respective facets Q v 1 , Q v 1 , . . . Q v |ν| are also observed, or required to be present. The label q was used to group this collection of measurements since such a collection frequently describes the given information from a question whose answer is simply the new amount of the distinguished facet that becomes present due to the occurrence of different amounts of the other independent facets. This answer is obtained by performing the appropriate unit conversions and using the assumption that changes in the amount of the distinguished facet occur in proportion to any changes made in the other independent facets. Using the previous list notation we see that the new situation can be described by:
[0000] {{a x ,a x u }←|{a v 1 ,a v 1 u },{a v 2 ,a v 2 u } . . . {a v |ν| ,a v |ν| u }} (2)
[0000] with a x representing the new amount of the distinguished facet that is to be determined (in chosen units a x u ). From this we see that since the amount of facet Q v i has changed by a factor of
[0000]
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[0000] the proportional relationship means that the amount of facet Q x (which is initially equal to q x *q x u ) also changes by this factor. Repeating this for all the factor changes associated with the other facets (and multiplying the results) we see that a measure of the total factor change due to all the independent facets can be determined by finding ax a x follows:
[0000]
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[0028] Essentially, equation (3) is just a straightforward application of the notion of proportionality amongst measurements of disparate units. Such an application does however, appear in different guises in a surprisingly diverse set of computations and hence, developing a flexible computer interface into which all these different computations can be inscribed, offers several benefits. Firstly, repeatedly performing such inscriptions develops an awareness that a variety of problems are really special cases of this more fundamental one (i.e. involving proportionality and unit conversions). Hence, recognizing that a particular problem is, in fact, such a special case can then lead to its immediate solution. Secondly, since inscribing a problem into an interface is equivalent to translating it into a more fundamental problem, if the solution to the fundamental problem has already been implemented in a computer program, then a solution to the problem of interest can be immediately and automatically computed. This automation can dramatically improve efficiency and accuracy of solutions in a wide range of problems. The importance of this automation is accentuated when such solutions are required from those with weak mathematical backgrounds or, even for those with strong numerate skills, for managing all the details in the case where the size of {V} becomes unwieldy.
[0029] The values for terms in expressions (1) and (2) are taken form the respective “Initial Values” and “Final Values” rows. Note that in this example the facet of interest is Q 2 which is indicated by the radio button selection in row x which in turn sets the corresponding values of {q x , q x u } and {a x , a x u }. The other facets on which Q 2 have been chosen to (proportionally) depend on are Q 3 and Q 5 which are indicated by the check box selections in row V thereby setting the values of {q v 1 , q v 1 u }, {a v 1 , a v 1 u } and {q v 2 , q v 2 u }, {a v 2 , a v 2 u }. The facets Q 1 and Q 4 are not relevant to this particular calculation (of a x ) and hence any values in the positions of {q 1 , q 1 u }, {a 1 , a 1 u }, {q 4 , q 4 u }, {a 4 , a 4 u } are ignored (they may however, become relevant in other possible calculations in which case the corresponding radio-button or check box would be selected). Note that this means that in any given computation there can be a certain redundancy built into the interface with the entries of certain columns left unused. This redundancy however (which in the actual operation of the interface can be made clear by dimming the unused columns), is actually a consequence of an important feature whereby all the different calculations can be performed from a single interface. This feature reduces the amount of time for users to find a page-specific calculation and also promotes an awareness of the fundamental proportionality argument being applied across seemingly diverse problems.
[0030] The point of the interface is to compute the amount of the facet of particular interest (which is dependent and proportional to the amounts of certain other facets as specified in the “initial values” row) when the amounts of the independent facets are varied (as specified in the “Final Values” row). Hence the amount of the facet of particular interest (in units a x u ) is given by the expression to the right of the “Evaluate” button and it is this amount that is output when the button is clicked. The algorithm is totally extensible by increasing the number of facets of interest in any system being studied. That is, the size of Q can be increased arbitrarily which in turn, would be reflected in the interface through the appearance of additional columns. Indeed, the usefulness of this interface is likely to increase exponentially with the number of facets of a system being measured. This is because all the different facets and any possible conversions can be conveniently managed from the one interface—as opposed to the increasingly complex arithmetical calculations required without the interface. This extensibility is also likely to be exercised as increased understandings of systems frequently occur through analyzing the effects of more and more of its constituent facets. For example, the standard facets associated with the most effective amount of a drug to administer includes volume (as specified by stock concentration) patient mass and time; it is feasible however, that more precise and effective dosages can be delivered by incorporating such facets such as surface area, patient age and potentially, DNA sequences. (Note that these would then appear as additional columns and without any alteration to the basic algorithm used in equation (3) assuming that increases in any selected facet cause proportional increases in any selected facet of interest—if the relationship turns out not to be proportional then the algorithm can be straightforwardly adjusted as required).
[0031] The input fields as shown in the FIGS. 2 and 3 of the drawings, are arranged in rows on an interface screen. The weight and volume units to be used are set in the top row in the stock weight and stock volume. Drop down menus in each window provide a range of units to be selected.
[0032] Learning how to apply the interface of this invention to a range of Drug Calculations is a two-step process. The first step involves specifying ( FIG. 2 . Row Q) the relevant information provided by the problem (typically this describes the dose to be administered). The second step involves specifying ( FIG. 2 . Rows A, a 1 , a 2 ) what the problem is asking (typically this involves describing the dose in terms of other quantities of interest). With these specifications correctly entered, clicking “Evaluate” actuates the algorithm to output the correct answer as illustrated in FIG. 3 . That is, with respect to FIG. 2 . there are the following steps:
[0033] 1. Specify the problem:
a) Specify the relevant quantities (along with the correct units) in Row Q (The“Stock Weight ” and “Stock Volume” fields can also be used if necessary).
[0035] 2. Specify the answer:
a) Specify the “main quantity” being sought by selecting the corresponding radio button in row a 1 . b) Specify the other quantities (which the “main quantity” varies with respect to) by selecting the corresponding checkboxes in row a 2 . c) Specify the quantities (along with the correct units) in row A in which the answer needs to be expressed.
[0039] Note that learning to use the interface is perhaps best accomplished by practising on a variety of examples. A range of examples (along with their Solutions in terms of the steps described above) may be provided within links on the interface screen. Clicking the “Evaluate” button within these produces the correct answer for any particular question.
[0040] The interface contains and that particular problems may not require the filling in of every single field. What relevant fields used by the interface are specified by rows a 1 and a 2 . In particular, the checkbox's in row a 2 specify that information in the corresponding columns (as indicated by the green strips) be used while the radio-button selection in row al specifies the “main quantity” (of the columns selected in a 2 ) that is being requested in the question.
[0041] In row Q the pairs Q 1 -Q 4 are filled in directly from the information as described in the question. If the question contains information about a stock concentration these can be entered via the Stock Mass and Stock Volume fields.
[0042] In all the fields Q 1 -Q 4 & A 1 -A 4 if the information given in the question is given in “per form” (e.g. ml/kg/hr) fill in the numerical field with a 1.
[0043] Mathematically what the interface essentially does is the following: For the column checked by the radio button, the value in the top row Q (having first been converted into the same units as that specified in the corresponding bottom row A) is divided by the corresponding column value in the bottom row A. For the columns selected by the checked boxes, the value in the top row Q (having first been converted into the same units as that specified in the corresponding bottom row A) is divided into the corresponding column value of the bottom row A. The numbers so obtained in these steps are then all multiplied together. It turns out that this generic conceptualization underpins any type of calculation although you can always see the actual arithmetical calculations underneath the computed answer as shown in FIG. 2 .
[0044] The problem solved in FIG. 2 is:
[0045] Order: Dopamine infusion 20 ml/1 hr
[0046] Stock: Dopamine 400 mg in 5% Dextrose 500 ml
[0047] 1. If the patient is 50 kg how many mcg/min/kg will be infused?
[0048] The initial dose to be administered is contained in the order “Dopamine infusion 20 ml/1 hr ” as reflected in the entries of Q 2 and Q 3 . It is to be assumed that the initial dose was devised for the patient being discussed and hence it has been calculated per 50 kg as shown in Q 4 . There are two questions being posed here; the first involves a Weight rate per kilogram of patient whereas the second asks for a Weight rate that includes the patient's entire weight. Since the initial dose is a volume, this volume first needs to be converted into a weight using the concentration as provided in the stock details. Hence, the details contained in the Stock information “Dopamine 400 mg in 5% Dextrose 500 ml” appear in the “Stock Weight” and “Stock Volume” fields while a “?” is inserted in the numeric field of Q 1 . The “main quantity” of interest is contained in the “mcg” part of the “mcg/min/kg” request leading to the checking of the “Weight” radio button of row a 1 in FIG. 2 . This weight is to be determined in relation to both the weight of the patient and over a particular time period and hence the “Patient Weight” and “Time” checkboxes of row a 2 both need to be checked in FIG. 2 . The dosage weight is being calculated per (1) minute and (1) kilogram of patient as reflected in the entries of A 3 and A 4 respectively.
[0049] Clicking the “Evaluate” button of FIG. 2 . yields an answer of “5.33 mcg/min/kg ”. The bracketed response beneath the answer shows the actual arithmetic performed. In particular, The first entry in the list below the answer shows the intermediate calculation that uses the stock concentration to determine the “?” entry of Q 1 —namely that the 20 ml volume equates to a weight of 16 mg in the infusion. The second entry then shows how the final answer of 540 is obtained in the normal operation of the interface using rows Q and A.
[0050] FIGS. 1 and 2 depict an interface of 28 inputs that can perform all possible drug calculations that use Dose Weight and Volume, Time and Patient Weight.(Note that all these are not used in every single calculation but each calculation uses a certain subset of these inputs depending on what inputs are “activated” by the user).
[0051] It is the ability, in a single interface, of being able to perform a large number of dosage calculations from a relatively small number of inputs that distinguishes this invention from prior-art devices. This property can be made precise by measuring the device's “Interface Efficiency” (IE) where IE=#calculations/# inputs. For comparison purposes, the Interface Efficiency of prior-art can be meaningfully measured by concatenating all prior art (interfaces) into a single “super interface”. The (much larger) number of inputs appearing in the resulting “super interface” produces a significantly reduced Input Efficiency that effectively renders it unusable in practice.
[0052] While other embodiments (e.g. design improvements) of this interface are possible, the inventions core effectiveness ultimately resolves to the large Interface Efficiency it produces (which followed naturally from recognizing the common principle of proportionality used in the algorithms for almost all dosage calculations).
[0053] An example of another embodiment of this invention is given in FIG. 4 where a horizontal format that promotes a left to right workflow as well is used together with the introduction of a commonly needed stock-concentration component. That is, The first calculations in the stock measure interface on the left convert the drug as stocked into the same units as prescribed by the physician and the second calculation in the drug dose interface presents the unit dosage to be given to the patient. The two calculations are separated by a screen button or valve 11 that connects the stock measure interface to the drug dose interface so that output from a stock concentration calculation can be plugged back into the drug dose interface. When values are entered in the drug measure interface the values are colour coded as primary and secondary values and pressing the equal button 12 displays the calculation. The drug dose interface works in a similar way and pressing the equal button 13 displays the calculation.
[0054] In the interface illustrated, four horizontal bands (corresponding to drug weight, drug volume, time and patient weight) have been used. This choice has been made because the overwhelming majority of calculations required by nurses employ these variables alone. There are however, other quantities that are sometimes used (e.g. a patient's surface area, age etc.). Furthermore, it is inevitable that medical advances will uncover the importance of other quantities (e.g. patient's sex, kidney function, DNA etc) that need to be routinely factored into standard drug administration. Despite the improved embodiment presented in FIG. 4 and/or other potential extensions, the inventions core idea of obtaining a maximal IE ratio is always to be retained since it is this feature that ultimately renders the device usable in the face of any increases in complexity.
[0055] The interface and algorithm of this invention is “future proof” in one important sense. The current infrastructure contains an inbuilt extensibility whereby these other quantities found to affect a dose's efficacy can be subsequently and seamlessly added. That is, the interface's design allows news rows to be added for each new variables found to impact on a drug's dose.
[0056] The algorithm illustrated has been written in Mathematica. However the algorithm may be written in any suitable programming language depending on the hardware used. For calculators or hand held PDA's the language C is most suitable because it has a smaller memory requirement.
[0057] Because of the algorithm, verification of each calculation is feasible. Essentially the software traces the computation pulling out the parts used in the arithmetic. While Mathematica is usually used for more sophisticated computations than these type of arithmetical calculations its use is important in ensuring correctness (both due to its tested algorithms and numerical precision).
[0058] The importance of getting these computations right need not be understated but using Mathematica also opens up the possibility for further extensions (e.g. Graphs, feedback, more complicated drug or varied calculations)
[0059] To make the interface accessible from the Web, web Mathematica may be used while its formatting is controlled by CSS files which are automatically generated from within Mathematica. However the Java language could also be used with some benefits.
[0060] Extra columns can be seamlessly added and the fields easily customized to include other units.
[0061] It is within the scope of this invention to provide for machine reading of some of the inputs. This could include equiping a hand-held device according to this invention with the ability to read the barcode on the drug packaging and in particular import the drug's concentration values into its interface. This would enable pharmaceutical companies to avoid having to provide hospitals with all the variety of so-called “unit doses”, which are doses ready to be directly administered for all the different types of patients. With a bar-code reading facility the pharmaceutical companies would be able to continue with their current packaging as the automatic reading of the bar code would be converted by the device of this invention into a read out telling the nurse how much to measure out.
[0062] From the above it can be seen that the present invention provides a simple single interface that can deal with a wide range of computational situations. This invention differs from the prior art in that it offers a complete technological solution to the automation of drug calculations. This includes pedagogical design, transparency in the selected algorithm, inbuilt extensibility and back-end connections to an industrial strength computational engine and a comprehensive pharmacopoeia.
[0063] Those skilled in the art will realize that the embodiments illustrated are only some of many ways of presenting the input and output data and other formats may be used without departing from the essential teachings of this invention. That is, other embodiments and extensions can be built on but the inventions essential usability derives from the way in which it maximizes its Interface Efficiency or equivalently the way in which the invention minimizes the number of inputs relative to the range of possible dosage calculations an interface can offer.
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A method of administering a drug to a patient which involves providing a single interface for entry of data including one or more of drug identity, dosage rate, prescribed dosage form, concentration and form of drug, and patient body weight, processing the input data using an algorithm which converts the input data into a set of instructions for administering the drug including the amount and time for the first and subsequent administrations, administering the drug and recording the amount and times on the patients record.
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This is the U.S. national phase of International Application No. PCT/JP2004/014432, filed Sep. 24, 2004, which claims priority from Japanese Patent Application No. 2003-338541 filed Sep. 29, 2003.
TECHNICAL FIELD
The present invention relates to a sealing ring. Specifically, the present invention relates to: a sealing ring which is to be fitted to a face-to-face part of members to thus serve to seal a space between both members in such as vacuum devices and piping instruments required to have high air tightness; and a managing system for such a sealing ring.
BACKGROUND ART
As a typical sealing ring, an O-ring is known. The O-ring is molded in a ring shape with an elastic material such as rubber, and its section is O-shaped. Depending on a required performance and a use, various sealing rings having sectional shapes different from that of the O-ring are also proposed.
The sealing ring typified by the O-ring is used in places where a sealing function such as air tightness or water tightness is required in various industrial equipments and devices.
Under general use conditions of the sealing ring, it is inevitable that an elastic material composing the sealing ring changes in material property or deteriorates in physical property with the passage of time. The sealing ring having deteriorated in property is exchanged with a new sealing ring. An exchange timing of the sealing ring varies with use conditions such as a load and an environment when using it. Some sealing rings may be used for several years, and other sealing rings must be exchanged in a short period not more than several months.
For example, a sealing ring to be attached to a valve of a semiconductor-producing device and its opening-and-closing cover is used under severe conditions such that: high air tightness is required, a load applied upon using is large, and further, the sealing ring has a possibility of contacting with a plasma gas or a corrosive gas. Under such use environments, it is necessary to detect deterioration of a performance of the sealing ring surely and quickly or to surely exchange the sealing ring before its performance is deteriorated. If the use of the sealing ring with the deteriorated performance is continued, a quality performance of a semiconductor product is damaged to thus deteriorate the product yield.
Conventionally, in order to judge whether or not the sealing ring needs to be exchanged, it is necessary that a device fitted with the sealing ring is decomposed to expose the sealing ring and observe it, or that the sealing ring is fetched out to inspect it by an inspection apparatus.
Patent document 1 below proposes a technology in which an inner signal member of a color different from the surface of the O-ring is embedded in the inside of the O-ring. This patent document states that: if the surface of the O-ring is deteriorated, then the inner signal member is exposed to the surface, so it is possible to judge the deterioration of the O-ring from the difference in color.
[Patent Document 1] JP-A-168348/2002 (Kokai)
As to conventional methods to judge the exchange of the sealing ring or to manage the sealing ring, it is difficult to appropriately judge the exchange or make strict management about individual sealing rings when they are used.
For example, as to the art described in the above patent document 1, unless the O-ring is fetched out from its fitting part to observe its surface, it is not possible to judge the deterioration of the O-ring from whether the inner signal member is exposed or not. In order to fetch out the O-ring from its fitting part, it is necessary as a matter of course that the working of the device including the fitting part is stopped to decompose a peripheral device including the fitting part of the O-ring. If the O-ring is not deteriorated, the reworking of the device will be performed after fitting the O-ring again and reassembling the device. During this time, a time loss is large and a human burden is also heavy.
A method is also carried out in which: there are beforehand collected the data with relation to a degree of progress in a deterioration of a performance and a life duration about the sealing ring in a specific fitting place, and therefrom the exchange timing of the sealing ring is estimated. However, unless there is any past data such that the load and environmental conditions, acting on the sealing ring, conform completely to those of the present sealing ring, it is difficult to accurately estimate the exchanging timing. The progress of the performance deterioration may be different due to an individual difference between the sealing rings.
It has a limitation to estimate a degree of progress in a deterioration of a performance and a life duration about each of the sealing rings by only the data collected in the past.
On the scene using a conventional sealing ring, the sealing ring is exchanged if there has passed a definite period during which it is, from such as past experiences, considered possible to sufficiently maintain the performance of the sealing rings regardless of a usage environment and an individual difference. However, this results in also exchanging the sealing ring having a sufficient sealing function, so this leads to much waste of money. The number of times of the exchanging of the sealing ring increases more than necessary, so that unfavorably the operation rate of the apparatus to which the sealing ring is attached decreases largely.
In order to record a history (e.g. a production period and a use-start period) and other managing information with respect to each sealing ring and exchange a sealing ring to be exchanged on the basis of this managing information, it is necessary to strictly manage each sealing ring and its managing information while making their one-to-one correspondence. This is very troublesome. It is very troublesome to give an identification number to each sealing ring and record it every time the sealing ring is attached or exchanged on the scene using the sealing ring. As to a sealing ring in use incorporated within the equipment and apparatus, it is difficult to check, from the outside, which identification number this sealing ring has.
DISCLOSURE OF THE INVENTION
OBJECT OF THE INVENTION
An object of the present invention is to male it possible to accurately and simply manage the aforementioned performance deterioration and life duration of sealing rings and other various information about each sealing ring.
SUMMARY OF THE INVENTION
A sealing ring according to the present invention is a sealing ring to be fitted to a face-to-face part of members to thus seal a space between both members, comprising: a main body part that is ring-shaped and is capable of becoming elastically deformed; and a circuit chip that is attached unitedly to the main body part and has an information-transmitting means for transmitting the information with the outside of the sealing ring.
[Sealing Ring]:
The sealing ring has a function to be fitted to a face-to-face part of members to thus seal a space between both members. Its basic materials, structures, and usage modes are common to those of conventional sealing rings.
As modes of fitting the sealing ring, there are the following ones: a mode in which the sealing ring is fitted to a junction portion of members that are used in a fixed state such as a container-shaped processing chamber and its cover in a semiconductor-producing device; and besides, a mode in which the sealing ring is fitted to a portion where a sealed state and a sealing-released state are repeated such as a cover and an opening of an opening and closing cover; and a mode in which the sealing ring is fitted to a portion where members rub or rotate on each other such as a shaft and a hole.
[Main Body Part]:
The main body part is a structure as a main part of the sealing ring and is ring-shaped and is capable of becoming elastically deformed and performs the sealing function. The same materials and structures as those of conventional sealing rings can be used. It is also possible to utilize conventional sealing rings or commercially available sealing rings as they are.
As a typical example of the shape of the main body part, a sectionally circular O-ring can be cited. As to the sectional shape, there can also be adopted a rectangular one, a trapezoidal one, and other ones.
As materials of the main body part, the same elastic materials (e.g. rubber, resins, elastomers) as those of conventional sealing rings may be used. Specifically, such as fluororubber and silicon rubber can be cited. A blend material (combining a plurality of rubber materials) and a polymer alloy material can be also adopted. A composite material in which a metallic or fibrous material is embedded can be also adopted.
The ring shape of the main body part is generally a circular ring shape. However, in accordance with the form of the place where the sealing ring is fitted, an ellipse ring shape, an oval ring shape, and a rectangular ring shape may also be available.
The size of the main body part is different depending on its usage purpose and required performance. In the case of embedding a circuit chip including a pressure sensor or the like, a main body part having a sectional diameter of not less than about 4 mm is used.
[Circuit Chip]:
The circuit chip is a minute piece, that is, a chip, in which an electric and electronic circuit chip having an electric or electronic processing function is incorporated.
On a substrate made of a silicon, a resin, a metal or the like, there is formed a prescribed circuit by using various thin-film-forming means, thick-film-forming means, photolithography technologies or the like. Alternatively, there is also a circuit chip having a structure such that another semiconductor element is mounted on or embedded in a wiring substrate. In addition, a power supply circuit (e.g. battery) for activating the circuit can also be provided. A working power source may be supplied from the outside.
The shape of the circuit chip is different depending on the function or circuit to be incorporated or on the size and shape of the main body part of the sealing ring. Favorable is a shape that can be easily attached to the main body part and spoil the sealing function of the sealing ring. Generally, the circuit chip is a thin plate shape. Alternatively, there are also the following types: a thick-block-shaped type; a bar-shaped type; a type having irregularities on its surface, and a partly perforated type.
The size of the circuit chip is set at a size such that: the circuit chip can be attached to the main body part of the sealing ring, and the sealing function of the sealing ring is not spoiled. For example, in the case of the circuit chip including a pressure sensor or the like, it is preferable to set the size of the circuit chip at an outer diameter size of not more than 60% relative to the sectional diameter of the main body part.
<Attaching to Main Body Part>:
The circuit chip is attached unitedly to the main body part of the sealing ring.
The attaching structure and the attaching means are different depending on the objective function of the circuit chip and its structure or on the function of the sealing ring.
The circuit chip may be eternally attached and fixed to the main body part of the sealing ring, or it may be detachably attached thereto.
The circuit chip can be embedded within the main body part of the sealing ring. If the circuit chip is completely embedded within the main body part, then the appearance of this sealing ring is identical with conventional sealing rings without the circuit chip. A portion of the circuit chip may protrude or stick out of the main body part. In the case where a member that needs to be disposed outside the sealing ring (e.g. wiring or an antenna as an information-transmitting means) is connected to the circuit chip, this member is disposed so as to be exposed to outside the main body part.
In order to attach the circuit chip to the main body part into a state embedded therein, the circuit chip can be incorporated by forming a notch or hole in the main body part wherein the notch or hole goes through from the outer periphery of the main body part to its inside. Furthermore, it is also possible to bond the circuit chip into the notch or hole by an adhesive. It is also possible that, when molding and producing the main body part, the circuit chip is united therewith by molding the main body part in a state where the circuit chip is embedded in a mold.
It is also possible that the circuit chip is attached unitedly to the outer surface of the main body part. Specifically, the adhesive can bond the circuit chip to the main body part. It is also possible to use an adhesive tape, a pin fitting or the like to fix the circuit chip to the main body part.
It is also possible that: the circuit chip is attached to another member (e.g. a capsule, a pin, a sheet piece) in advance by incorporating the circuit chip in this member or fixing the circuit chip to this member, and then this member to which the circuit chip has been attached is attached to the main body part of the sealing ring. Thereby, a minute circuit chip can be easily attached. During the attaching operation, it is possible to prevent the circuit chip from being damaged or being lost and it is possible to accurately set the attaching position or posture of the circuit chip.
The attaching position of the circuit chip in the sealing ring is desirably a position where no bad influence is exercised on the sealing function. For example, no circuit chip is made to exist in a place where a contact surface pressure is generated when the circuit chip contacts with the both-side members to be sealed by the sealing ring. In the case where the sealing ring is used for sealing a space becoming a high vacuum environment, a plasma generation environment, a specific gas environment, or a high temperature environment off from the external world with a normal atmospheric pressure, if the circuit chip is attached to a range, facing the external world, of the sealing ring, then the sealing function is not spoiled, and the circuit chip is not exposed to the above-described severe environment. It is preferable that the notch or hole for attaching the circuit chip is also provided in the side facing the external world similarly to the above. If the circuit chip is embedded in the main body part of the sealing ring so as not to be exposed to the surface of the sealing ring, then the circuit chip can be blocked off from the external severe environment.
Either only one or more circuit chips can be provided to the sealing ring. For example, if the circuit chips having a sensor function are disposed in a plurality of places in a peripheral direction of the sealing ring, then it is possible to accurately know the state on the entire periphery of the sealing ring by detecting various state quantities having a possibility of dispersion in the peripheral direction of the sealing ring. Alternatively, it is also possible to dispose a plurality of circuit chips having different sensor functions, or a circuit chip having a sensor function and a circuit chip having an information storage function, in the same position or different positions in the same sealing ring.
[Sensor Part]:
A sensor part can be provided to the circuit chip.
The sensor part has a sensor function to detect a physical or chemical state quantity. The state quantity is sufficient if the circuit chip can detect it and if it needs to be detected under the usage environment of the sealing ring. As the state quantity, there are various physical or chemical state quantities. For example, there is a pressure sensor for detecting a pressure, and also there is a temperature sensor for detecting a temperature. Also, there can be cited a distortion sensor, a gas sensor, a vacuum sensor, a temperature sensor and the like. As the pressure sensor, there are a distortion gauge type pressure sensor, a capacitance type pressure sensor, and a piezo resistance element type pressure sensor and the like. As the temperature sensor, there are a contact type thermocouple and the like.
Depending on the function of the sensor, the structure and circuit constitution of the sensor part are different. The sensor part may be composed only of a sensor element or it may include the sensor element, a control circuit of the sensor element, a signal-processing circuit and the like. Depending on the state quantity to be detected by the sensor, the entire structure of the circuit chip and its attaching structure to the sealing ring are different.
For example, as to the pressure sensor for detecting a pressure to be applied to the sealing ring or an inner stress of the main body part in use condition to carry out the sealing function, the sensor part is disposed in a place where it can easily detect the pressure to be applied to the sealing ring or the inner stress. Specifically, it is possible to embed the sensor part within the main body part of the sealing ring between surfaces of contact of the sealing ring with both members to be sealed by the sealing ring.
For the circuit chip provided with the sensor part, an MEMS (Micro Electro Mechanical System) technology can be utilized. In the MEMS technology, it is possible to incorporate the sensor part and a processing circuit of the detection information into the circuit chip. Alternatively, it is possible to incorporate a mechanical operation structure into the sensor part. In the case of the pressure sensor, a diaphragm structure can be made therein.
[Information Storage Part]:
The circuit chip can be provided with an information storage part for storing the managing information about the sealing ring.
A memory circuit or a memory element can compose the information storage part. The memory may be a ROM memory such as a nonvolatile memory, or a writable or rewritable memory is also available. The memory capacity can be set in accordance with the information quantity to be stored in the information storage part.
In the circuit chip, an electronic circuit for writing or rewriting the information in the information storage part can be incorporated. It is also possible to constitute the circuit so that the detection information detected by the aforementioned sensor part can be written in the information storage part. Furthermore, it is also possible to store the instruction information for controlling the operation of the sensor part.
As the circuit chip having the information storage part, a non-contact IC chip can be used. Specifically, an RFID (radio frequency identification) chip can be used. The RFID chip has a memory for storing the information therein, and it can read the storage information from the memory in non-contact by means of an induction electromagnetic wave or the like to be supplied from an external reading apparatus. An antenna circuit for a radio frequency is incorporated in the RFID chip. The RFID chip is a radio system which does not need wiring as the information-transmitting means, and the RFID chip does not need a working power source, either.
<Managing Information>:
As the managing information to be stored in the information storage part, there is adopted the information useful to favorably exercise the performance and function of the sealing ring or to make the handling of the sealing ring easy. Thus, the specific content of the information is not limited.
Combining a numeral, a character, a mark and the like can constitute the managing information.
As a specific example of the managing information, a production number can be cited. The production number specify each sealing ring. There is a lot number assigned to a group of sealing rings produced in the same operation process or in the same period of time during the production. There is also a mark representing the production factory, and there is also the information about the production period of time to specify the year, month, day, and time when the sealing ring was produced, and there is also the model number of the sealing ring, and there is also a mark representing the material of the sealing ring. These pieces of information are decided during the production of the sealing ring and therefore can be stored in the information storage part during or just after the production of the sealing ring.
Some information may be decided or changed after the production of the sealing ring. For example, there is information about a market channel, a market destination, transport, and storage of the sealing ring, and there is information about a use-start period of the sealing ring, and there is information about a use place of the sealing ring and about apparatus to which the sealing ring is attached. In cases of these pieces of information, when having been decided or changed, they can be written or rewritten in the information storage part.
During the use of the sealing ring, some pieces of information are decided or changed. For example, there are such as a history of a pressure and a temperature to act on the sealing ring, a history of the inner stress generated in the sealing ring, and environmental conditions.
It is also possible that: the managing information to be stored in the information storage part is limited to only the individual identification number of the sealing ring, and the other managing information is recorded in an information-processing apparatus or a database for management together with the identification number. In this case, the information storage capacity of the circuit chip of the sealing ring is saved to a small one, and this is effective for making the circuit chip minute.
[Information-Processing Apparatus]:
This apparatus serves to transmit and receive the information with the circuit chip to electronically process the information.
Information-processing apparatus such as conventional computers can be adopted. A controller, a measuring device, and a data-processing apparatus, corresponding to the sensor part incorporated in the circuit chip, can be also adopted.
The information-processing apparatus can store the information about the sealing ring. The information-processing apparatus can store not only the same information as stored in the information storage part of the circuit chip but also other information. It is also possible that: the stored information is accumulated in an external storage apparatus with the passage of time or recorded on an external recording medium. It is also possible that: the information-processing apparatus exchanges the information about the sealing ring with the database.
The information-processing apparatus can be provided with an informing means for prompting an exchange of the sealing ring or giving warning of a malfunction of the sealing ring or of the apparatus to which the sealing ring is attached. The informing means includes such as a warning light, a warning buzzer, and a display. It is also possible to display the managing information about each sealing ring on a display of the information-processing apparatus or to display a list of the managing information about a plurality of sealing rings.
The information-processing apparatus can be made to have a function to write or rewrite the information in the circuit chip. For example, a processing circuit to write or rewrite the information in a memory constituting the information storage part of the circuit chip can be provided to the information-processing apparatus.
The information-processing apparatus may be incorporated in the apparatus equipment used with the sealing ring fitted thereto, or the information-processing apparatus may be set separately from the apparatus equipment to which the sealing ring is fitted. If necessary, a transportable information-processing apparatus may be transported to a place where the sealing ring is fitted.
The information-processing apparatus can be connected so that the information-processing apparatus can exchange the information with the control system for managing and controlling the entire apparatus to which the sealing ring is fitted. It is possible that the information about such as the state of the sealing ring and the degree of deterioration of performance is utilized for the managing control of the entire apparatus to which the sealing ring is fitted.
[Information-Transmitting Means]:
If necessary information transmission can be carried out between the circuit chip of the sealing ring and the outside of the sealing ring, then various information-transmitting means that are utilized for information transmission between conventional instrumental devices can be used.
Generally, the information transmission by means of electric wiring can be adopted. An optical communication line can also be utilized. Information-transmitting means by means of radio without using the wiring can also be adopted.
In order to perform the information transmission by radio bi-directionally, it is enough that a radio transmission and reception circuit is provided not only in the circuit chip but also in the information-processing apparatus. If the information transmission is sufficient in only one direction, then even it is enough to merely provide a transmission circuit to either one of them and a reception circuit to the other. For example, if the sensor information detected by the circuit chip is merely transmitted to the information-processing apparatus, then the transmission circuit is provided to the circuit chip, and the reception circuit is provided to the information-processing apparatus. As the information-transmitting means not needing the wiring, it is possible to utilize radio electromagnetic waves, and besides, such as infrared rays and supersonic waves.
The information-transmitting means may be combined with a power-source-supplying means for supplying the working power source to the circuit chip.
[Judgment of State of Sealing Ring]:
On the basis of the information from the sensor part and the information storage part belonging to the circuit chip, it is possible to judge the life duration or exchange timing of the sealing ring. Also, it is possible to judge to what degree the deterioration of performance of the sealing ring has proceeded, and further it is possible to know that a malfunction has occurred to the sealing ring.
Specifically, when the state quantity detected by the sensor part has gone beyond or below the prescribed limit value, it can be judged that the life duration of the sealing ring has come to the end. The prescribed limit value can be determined from experimental or empirical data in advance. When the state quantity has rapidly changed or when the changing rate of the state quantity has become excessive, it can also be judged that the life duration has come to the end.
For example, if, when the pressure generated within the main body part, that is, the inner pressure or stress, is detected by the sensor part, the decrease of the inner stress after the passage of time relative to the inner stress at the start of the use, namely, the inner stress alleviation ratio, has exceeded the prescribed limit value, then it can be judged to be time to exchange the sealing ring. If how long the sealing ring can be used from now is judged from the value of the inner stress alleviation ratio detected by the sensor part, then the future exchange timing can be also estimated. If a gas leakage or temperature change caused by deterioration of the sealing function is detected by the sensor part, then the deterioration of performance of the sealing ring can be also known.
If, like the semiconductor-producing device, the use environment is such that the state quantity (e.g. temperature, pressure applied from the processing chamber to a place where the sealing ring is attached) largely changes between when the apparatus is activated and when the apparatus is not activated, then the number of times of the activation can be known by detecting the number of times of the change in pressure or temperature by the sensor part. When the number of times of the activation has exceeded a definite number of times, it can be judged that the life duration of the sealing ring has come to the end. In the same way, if the usage is such that the stress is repeatedly generated in the sealing ring, then it is possible to judge the life duration from the number of repeats of the pressure change. If, when the number of times of the opening and closing of an opening-and-closing valve is detected from the change of the pressure or stress, the number of times of the opening and closing has exceeded a definite number of times, then it is also possible to judge that the life duration of the sealing ring has come to the end.
When the cumulative values of the state values (e.g. temperature or stress) detected by the sensor part have exceeded their respective prescribed limits, the sealing ring may be exchanged. In this case, it can be perceived that such as material deterioration of the sealing ring and its stress alleviation proceed due to the accumulation of the state values (e.g. temperature or stress). Therefore, the life duration of the sealing ring is estimated from the cumulative values of these state values. In this case, it is enough that the correlations of the deterioration of the performance of the sealing ring with the cumulative values of the aforementioned state values are determined from experimental or empirical values in advance.
It is also possible to judge the deterioration of performance of the sealing ring comprehensively from a plurality of state quantities detected by the sensor part. For example, if the temperature environment is a high-temperature and severe one even though the decrease of the inner pressure of the sealing ring or its inner stress alleviation ratio is the same, then it can be perceived that the performance rapidly deteriorates to thus come to the end of the life duration. Thus, if the inner stress alleviation ratio is corrected according to temperature conditions, then it is possible to judge the life duration more accurately and further to correct the inner stress alleviation ratio according to environmental conditions other than the temperature.
It is also possible to judge the life duration of the sealing ring on the basis of the information stored in the information storage part. For example, it is judged that the exchange timing has come if the passage period of from the production period or use-start period (stored in the information storage part) up to now has exceeded a prescribed period of time. It is also possible that: a stored product of the same lot number as of the sealing ring is separately tested for durability and, from its result, the exchange timing of the sealing ring of the same lot number is decided.
It is also possible to judge the life duration of the sealing ring by comprehensively judging the detection information of the sensor part and the storage information of the information storage part. For example, it is possible that the value of the aforementioned stress alleviation ratio is corrected on the basis of the time having passed from the use-start time. Even if the stress alleviation ratio is small, there is a possibility that the performance is deteriorated as to the sealing ring having been used for a long period of time from the use-start. Therefore, it is possible to exchange the sealing ring early at a stage a little before the stress alleviation ratio becomes the prescribed limit value. In addition, in the case where the stress alleviation ratio has rapidly changed though the period of time from the use-start is short, then, judging that a malfunction has occurred to the sealing ring, the sealing ring can be exchanged.
It is possible to correct the limit value of the aforementioned stress alleviation ratio, or to correct the intervals of the exchange timing, on the basis of differences between usage places as to conditions (e.g. degree of environmental severity, degree of demand for reliability upon the sealing ring) known from the information about the places where the sealing ring is used as the storage information in the information storage part.
The above-described judgment or estimation of the life duration or exchange timing of the sealing ring can be determined by performing arithmetic processing with software that is incorporated in a computer constituting the information-processing device. The life duration of the sealing ring may be judged by accumulating the past empirical value or data and then comparing those data with various state quantities that are detected by the sensor part in an actual sealing ring.
[Sealing-Ring-Managing System]:
A system for managing the information about the sealing ring, including the aforementioned judgment of the state of the sealing ring, can be constituted.
The sealing-ring-managing system includes the sealing ring, the information-processing apparatus, and the information-transmitting means for transmitting the information between the circuit chip of the sealing ring and the information-processing apparatus.
The sealing-ring-managing system continuously manages the sealing ring in a state the sealing ring is fitted to the face-to-face part of the members. The information is inputted from the circuit chip of the sealing ring into the information-processing apparatus. The input information may include: the state quantity detected by the aforementioned sensor part; and the managing information stored in the aforementioned information storage part. The software or processing circuit, having been programmed in advance, carries out the information processing in the information-processing apparatus. The information that is processed in the information-processing apparatus and then outputted therefrom can include the information on the sealing ring such as life duration, exchange timing, degree of deterioration of performance, and whether or not there is any occurrence of malfunction. The output information can be outputted from the information-processing apparatus to another information display, another warning device, another information-processing apparatus or the like. It is also possible that the output information is written in the information storage part of the sealing ring.
EFFECTS OF THE INVENTION
As to the sealing ring according to the present invention, it is possible to accurately know or judge such as the performance property, life duration, and exchange timing about each sealing ring (which is used in the fitted place) by the information transmission between the circuit chip (attached unitedly to the main body part) and the outside of the sealing ring.
Particularly, if the circuit chip has the sensor part, then the physical or chemical state quantity of the sealing ring that is actually used can be detected, and the usage environment conditions of the sealing ring and its progress conditions in performance deterioration can be accurately known, so that it is possible to accurately judge the life duration of the sealing ring and its exchange timing.
In addition, if the circuit chip has the information storage part, then the histories (different between individual sealing rings) of from production till during use of the sealing rings, the properties of the sealing rings, and other information necessary for managing the sealing rings can be obtained from every individual sealing ring during its use, so that it becomes possible to accurately and easily manage the sealing rings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a semiconductor-producing apparatus which is fitted with an O-ring that illustrates a mode for carrying out the present invention.
FIG. 2 is a plan view of the O-ring partly notched.
FIG. 3 ( a ) is a sectional view illustrating a main part of the O-ring, and FIG. 3 ( b ) is a plan view illustrating this main part.
FIG. 4 is an enlarged sectional view of a fitted state.
FIG. 5 ( a ) is a sectional view illustrating an operation of attaching a circuit chip, and FIG. 5 ( b ) is a plan view illustrating this operation.
FIG. 6 is a perspective view illustrating a structure of attaching the circuit chip.
FIG. 7 is a sectional view of an O-ring that employs the attaching structure of the previous drawing figure.
FIG. 8 is a sectional view of an O-ring that illustrates another mode for carrying out the present invention.
FIG. 9 is a sectional view of an O-ring that illustrates another mode for carrying out the present invention.
FIG. 10 is a sectional view of an O-ring that illustrates another mode for carrying out the present invention.
FIG. 11 is a graph showing the results of the leakage test.
EXPLANATION OF THE SYMBOLS
10 : Semiconductor-producing apparatus
12 : Processing chamber
13 : Accommodating groove
14 : Cover body
30 : O-ring
32 : Main body part
40 : Circuit chip
42 : Wiring
43 : Information-processing apparatus
50 : Cutting-in tool
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, detailed descriptions are given about the present invention. However, the scope of the present invention is not bound to these descriptions. And other than the following illustrations can also be carried out in the form of appropriate modifications of the following illustrations within the scope not departing from the spirit of the present invention.
[Use Mode of O-Ring]:
The mode for carrying out the present invention, as illustrated in FIG. 1 , shows a state where an O-ring 30 , which is a sealing ring, is used in a semiconductor-producing apparatus 10 .
In the semiconductor-producing apparatus 10 , a cover body 14 that is freely openable and closeable is attached on a top surface of a container-shaped processing chamber 12 . In the processing chamber 12 and under the cover body 14 , electrodes 16 and 18 are disposed respectively. To the electrodes 16 and 18 , wirings 17 and 19 leading to a power source are connected respectively. To the processing chamber 12 , a ground wire 11 is connected. It is possible to apply a high frequency voltage or the like between the electrodes 16 and 18 . The processing chamber 12 is further provided with a vacuum exhaust pipe, a processing gas supply pipe and the like (though not illustrated in the drawing figure).
A material W to be processed, such as a semiconductor wafer, is disposed on the lower electrode 16 , and then a voltage is applied between the electrodes 16 and 18 . Thereby, plasma can be generated within the container body 12 to thus apply the plasma processing (e.g. plasma etching, plasma CVD) to the material W to be processed.
The O-ring 30 of a ring shape with a circular section is fitted to a place where an opening peripheral rim of the processing chamber 12 and the lower surface of the cover body 14 face each other, so that the airtight sealing is achieved in the face-to-face place. The O-ring 30 can prevent the vacuum state within the processing chamber 12 from being spoiled by intrusion of air from the outside and prevent the processing gas and the plasma gas within the processing chamber 12 from leaking to the outside.
[O-Ring]:
As shown in FIG. 2 , a circuit chip 40 is embedded in a portion of the O-ring 30 . As the material of a main body part 32 of the O-ring 30 , there is used a material (e.g. fluororubber) having a good elasticity and having a durability against a high heat, a corrosive gas, a plasma gas and the like that are generated in the processing chamber 12 . The circuit chip 40 is a minute part, which comprises a semiconductor element, an IC circuit or the like and performs an electric or electronic circuit function.
In this mode for carrying out the present invention, a pressure sensor is used as the circuit chip 40 . A wiring 42 connected to the circuit chip 40 is pulled out of the main body part 32 . The information detected by the pressure sensor of the circuit chip 40 is transmitted from the wiring 42 to the outside.
As shown in FIG. 1 , the wiring 42 is connected to an information-processing apparatus 43 that is set outside the semiconductor-producing apparatus 10 . The information-processing apparatus 43 comprises a computer or the like. The information-processing apparatus 43 and the circuit chip 40 of the O-ring 30 are capable of transmitting and receiving therebetween the information via the wiring 42 .
FIG. 3 shows the detailed structure of the O-ring 30 . As shown in FIG. 3( a ), the circuit chip 40 of a thin plate shape is embedded in the main body part 32 (with the circular section) from its outer periphery side along a diameter in a horizontal direction. A tip end of the circuit chip 40 reaches the inner periphery side that is more inside than a central line C along a vertical direction in the circular section of the O-ring 30 .
[Fitted State of the O-Ring]:
FIG. 4 shows a fitted state of the O-ring 30 in detail. The O-ring 30 is accommodated in a accommodating groove 13 that is formed in the opening peripheral rim of the processing chamber 12 of the semiconductor-producing apparatus 10 . The wiring 42 pulled out of the outer periphery side of the O-ring 30 is elongated along a wiring groove 15 formed from the accommodating groove 13 to the outer peripheral end in the opening peripheral rim of the processing chamber 12 , and then the wiring 42 is pulled out of the processing chamber 12 .
If the cover body 14 is put on the top surface of the processing chamber 12 and then fastened and fixed to the processing chamber 12 by bolt fastening or the like, then the section of the O-ring 30 that was circulate before its fitting is changed into the shape of a flat circle squashed in a vertical direction. Due to a repulsive force generated by elastic deformation of the O-ring 30 , the O-ring 30 and the lower surface of the cover body 14 are pressed into contact with each other to generate a contact surface pressure, so that the sealing function expresses itself. The O-ring 30 and the bottom surface of the accommodating groove 13 are also pressed into contact with each other, so that the sealing function due to a contact surface pressure is exercised.
The inner stress or distortion generated in the main body part 32 of the O-ring 30 is detected by the pressure sensor of the circuit chip 40 . The pressure applied to the main body part 32 is mainly generated between an area of contact of the main body part 32 with the lower surface of the cover body 14 and an area of contact of the main body part 32 with the bottom surface of the accommodating groove 13 . Therefore, it is necessary that there is the pressure sensor of the circuit chip 40 between these upper and lower areas. In addition, the flat surfaces of the circuit chip 40 is oriented so as to cross at right angles to the direction of the pressure applied to the O-ring 30 , namely, to the vertical direction. Thereby, it is possible to detect the change of the inner pressure of the O-ring 30 accurately with a high sensitivity.
The information detected by the pressure sensor of the circuit chip 40 is transmitted to the information-processing apparatus 43 via the wiring 42 . The information-processing apparatus 43 judges whether or not the output information from the pressure sensor is in a preset permissible range, or accumulates the data of the time-passage change, or gives the alarm if an abnormality has occurred.
In the fitted state shown in FIG. 4 , there is a possibility that: a vacuum pressure within the processing chamber 12 may be applied to the inner periphery side of the O-ring 30 , so that the processing gas or plasma generated within the processing chamber 12 may contact with the inner periphery side of the O-ring 30 . However, there is only the main body part 32 at the inner periphery side of the O-ring 30 similarly to conventional O-rings. Therefore, no trouble is caused with respect to the sealing function of the O-ring 30 . In addition, the end portion of the circuit chip 40 or the wiring 42 that are exposed to the outer periphery side of the O-ring 30 is not exposed to a corrosive atmosphere. Even if the wiring groove 15 having accommodated the wiring 42 communicates with the outer world outside the processing chamber 12 , no sealing function is spoiled.
[Performance Judgment from Inner Stress of the O-Ring]:
It is possible to know the deterioration of the life duration or sealing function of the O-ring 30 on the basis of the information from the pressure sensor of the circuit chip 40 .
The sealing function of the O-ring 30 is fulfilled by the surface pressure of contact of the O-ring 30 with both members existing on opposite sides of the O-ring, for example, the cover body 14 and the bottom surface of the accommodating groove 13 . If the contact surface pressure is sufficient, then no leak of the gas or the like occurs. If the contact surface pressure drops, then the gas or the like easily leaks and this results in deterioration of the sealing function.
Usually, at the start of the use of the O-ring 30 , a stress is generated within the O-ring 30 by the fastening force, and this leads to the generation of the contact surface pressure to a sufficient degree corresponding to this inner stress. With the passage of time, the alleviation of the stress makes progress within the O-ring 30 , and thus the contact surface pressure becomes small, so that the sealing function deteriorates. Then, if the contact surface pressure becomes lower than a prescribed limit value, then it can be judged that the life duration of the O-ring 30 has come to the end. However, it is difficult to directly measure the change of the contact surface pressure without spoiling the sealing function with respect to the O-ring 30 when it is used.
Thus, by detecting the change of the stress caused in the O-ring 30 , it is possible to indirectly know the above-described change of the contact surface pressure to thereby predict the performance deterioration and life duration of the O-ring 30 .
In order to detect the inner stress of the O-ring 30 , it is enough that the circuit chip 40 having the pressure sensor incorporated therein is embedded in the O-ring 30 . Corresponding to the inner stress being generated in the O-ring 30 , the pressure that is generated within the O-ring 30 and is detected by the pressure sensor makes a change. If a distortion gauge type pressure sensor is, for example, used as the pressure sensor, then the change of the distortion quantity generated within the O-ring 30 can be caught to thereby detect the change of the inner stress.
The distortion of the O-ring 30 corresponding to the contact surface pressure is mainly generated in a direction in which the contact surface pressure is applied. For example, in FIG. 4 , the contact surface pressure is applied in a vertical direction, so that the distortion is caused in the vertical direction. Accordingly, in order to know the change of the inner stress by the pressure sensor of the circuit chip 40 embedded in the O-ring 30 , it is desirable that the pressure sensor is put in such a position and posture as facilitates the detection of the pressure or distortion in the vertical direction. In FIG. 4 , the pressure sensor of the circuit chip 40 embedded in the O-ring 30 in a horizontal direction and placed crossing the vertical center line C of the O-ring 30 detects the vertical pressure to the O-ring 30 , so that it is possible to detect the inner stress of the O-ring 30 accurately with a high sensitivity.
[Attaching of Circuit Chip]:
FIG. 5 explains the operation of attaching the circuit chip 40 to the O-ring 30 .
The main body part 32 of the O-ring 30 has the very same material and shape as of conventional O-rings, and commercially available standard O-ring products are used as they are.
A cutting-in tool 50 of a thin plate shape having a cutting-in blade at its front end cuts into the above main body part 32 from the outer periphery side thereof along a diameter in a horizontal direction. The main body part 32 made of a rubber material or the like can be cut in relatively easily. After the front end of the cutting-in tool 50 has cut into a prescribed position, the cutting-in tool 50 is pulled out. The depth of the cutting-in can be set at about ⅔ of the linear diameter of the O-ring 30 .
After that, the circuit chip 40 is inserted into the cut formed in the main body part 32 . In a state where the circuit chip 40 has been inserted into a prescribed position, the circuit chip 40 is sandwiched in and thus surely fixed by elastic restoration of the cut in the main body part 32 . If necessary, the circuit chip 40 and the main body part 32 may be fixed together by use of an adhesive. By bonding the pressure sensor of the circuit chip 40 unitedly to the main body part 32 , it becomes possible to accurately detect the inner stress of the main body part 32 . In a fitting place that is exposed to a high heat such as in the semiconductor-producing apparatus 10 , it is desirable to use a heat-resistant adhesive.
[Other Modes for Carrying Out Present Invention]:
<Sandwiched Structure>:
In the mode shown in FIGS. 6 and 7 for carrying out the present invention, the fitted structure of the circuit chip 40 is different from that of the aforementioned mode for carrying out the present invention.
As shown in FIG. 6 , the circuit chip 40 in the shape of a minute rectangular piece is bonded to relatively large square resin sheets 44 , 44 in a state sandwiched in therebetween. The resin sheets 44 have rigidity in such a degree as to be able to maintain a horizontal posture in a self-standing state. As materials of the resin sheets 44 , an epoxy resin, an imide resin and the like can be used. A portion of the wiring 42 connected to the circuit chip 40 is also sandwiched in between the resin sheets 44 . However, the end portion of the wiring 42 is elongated outside the resin sheets 44 .
As shown in FIG. 7 , the circuit chip 40 in a state sandwiched in between the resin sheets 44 is fitted into the main body part 32 of the O-ring 30 in the same way as of the aforementioned mode for carrying out the present invention. If the same cut as above is made in the main body part 32 and if the resin sheets 44 are thereafter inserted into this cut, then the circuit chip 40 sandwiched in between the resin sheets 44 is smoothly inserted into the depth of the cut.
Incidentally, it is also permitted that: after the circuit chip 40 has been sandwiched in between the square resin sheets 44 in the way shown in FIG. 6 , a portion of each of the resin sheets 44 is cut off outside the circuit chip 40 to reduce the resin sheets 44 into the minimum necessary size, and then they are inserted into the cut.
In FIG. 7 , a portion of each of the resin sheets 44 , 44 protrudes a little out of the outer peripheral surface of the main body part 32 . However, no problem occurs to the sealing function of the O-ring 30 .
In the above ode for carrying out the present invention, even a very minute circuit chip 40 can be accurately and easily fitted into a prescribed position of the O-ring 30 . By sandwiching the circuit chip 40 in between the resin sheets 44 , the circuit chip 40 becomes easy to handle, and also a function to protect the circuit chip 40 is fulfilled.
<Sticking Tool>:
In the mode shown in FIG. 8 for carrying out the present invention, a sticking tool 52 is used.
The sticking tool 52 of a needle shape with a sharp tip end is stuck into the main body part 32 of the O-ring 30 from the outer periphery side thereof toward the center thereof. It is arranged the sticking tool 52 should be prevented from penetrating to the inner periphery side of the main body part 32 . The minute circuit chip 40 is accommodated, in a way of being dropped, into a hole formed in the main body part 32 . After that, if, as needed, an adhesive 34 is filled into the hole and then cured to thereby plug up the hole, then the circuit chip 40 comes into a state embedded in the main body part 32 . If the adhesive 34 is injected into the hole with a thread-filling nozzle like a syringe needle, then the adhesive 34 can be surely filled without contaminating the periphery with the adhesive. It is also possible that the circuit chip 40 is injected into the hole of the main body part 32 by the filling nozzle together with the adhesive.
<Pasted Structure>:
In the mode shown in FIG. 9 for carrying out the present invention, the circuit chip 40 is attached to the O-ring 30 by pasting.
By using an adhesive tape 48 , the circuit chip 40 is pasted to the main body part 32 of the O-ring 30 on the outer periphery side of the main body part 32 .
If the circuit chip 40 is provided with a memory circuit to store the information about such as class, production period, and production number of the O-ring 30 , then the O-ring 30 can be made to have the managing information. If the circuit chip 40 is provided with a circuit to supply a power source from the outside to the circuit chip 40 or transmit the information to the circuit chip 40 by means of such as induced electromagnetic waves, radiated electromagnetic waves, and infrared rays (though not being provided with the wiring 42 ), then it is possible to transmit the information to the outside and receive the information from the outside even without the wiring 42 . Specifically, the RFID chip or the like capable of transmitting and receiving the information by the infrared rays can be used as the circuit chip 40 .
In a state where the O-ring 30 is used in the form fitted to the semiconductor-producing apparatus 10 , a reader of the information-processing apparatus 43 can be brought near the outside of the semiconductor-producing apparatus 10 to thereby read the managing information stored in the circuit chip 40 . If necessary, it is also possible to write or rewrite the information from the information-processing apparatus 43 into the circuit chip 40 .
In the above mode for carrying out the present invention, if the circuit chip 40 and the adhesive tape 48 are separately prepared or they are prepared in the form where the circuit chip 40 has been pasted to the adhesive tape 48 in advance, then a conventional O-ring 30 (e.g. a commercially available product) composed only of the main body part 32 can be easily converted into the O-ring 30 provided with the circuit chip 40 . On the scene where the O-ring 30 is used, it is possible to, if necessary, produce the O-ring 30 provided with the circuit chip 40 .
Incidentally, in the mode (like the above mode for carrying out the present invention) that the circuit chip 40 is not directly embedded within the O-ring 30 , it is difficult to detect the inner stress of the O-ring 30 .
<Sticking Pin>:
In the mode shown in FIG. 10 for carrying out the present invention, a sticking pin 46 is used.
The sticking pin 46 in the shape of a push pin has a sharp front end and has a back projections that is sharpened in the direction opposite to the sticking direction on the way of the pin stem. On the pinhead portion, the circuit chip 40 is bonded.
If the sticking pin 46 is stuck into the main body part 32 of the O-ring 30 from the outer periphery side thereof toward the center thereof, then the sticking pin 46 is fixed to the main body part 32 . Since the pin stem of the sticking pin 46 has the back projection, the sticking pin 46 is immune against falling off during the use of the O-ring 30 .
Similarly to the aforementioned mode of FIG. 9 for carrying out the present invention, the managing information about the O-ring 30 is stored in the circuit chip 40 , the information is transmitted to the outside and received from the outside without the wiring 42 .
If the circuit chip 40 is minute, then it may be embedded within the pin stem of the sticking pin 46 . If this way is carried out, then it is easy to bring the circuit chip 40 near the center of the main body part 32 .
In the above mode for carrying out the present invention, if the sticking pin 46 having been provided with the circuit chip 40 in advance is prepared, then a conventional O-ring 30 (e.g. a commercially available product) composed only of the main body part 32 can be easily converted into the O-ring 30 provided with the circuit chip 40 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Descriptions are given below about working examples of some preferred embodiments of the O-ring, provided with the pressure sensor embedded therein, as a sealing ring according to the present invention and about the results of having evaluated the performance of the above O-ring.
[O-Ring]:
As the main body part, there was used a commercially available O-ring product (fluororubber-made FKM (D0270, produced by NIPPON VALQUA INDUSTRIES, LTD.), φ5.33 mm×53ID).
As the circuit chip, there was used a commercially available pressure sensor (PSM compact pressure sensor produced by a KYOWA ELECTRONIC INSTRUMENTS CO., LTD., a distortion gauge type). The pressure sensor gives an electric output corresponding to the distortion quantity generated by the pressure received in a direction crossing at right angles to its surface.
In the way shown in FIG. 5 , a cut was formed in the main body part from its outer periphery side along a diameter in a horizontal direction, and then the pressure sensor of a thin plate shape was sandwiched into this cut and thereby fixed. A wiring attached to the pressure sensor was pulled out of the main body part and then connected to a pressure-measuring apparatus (WGA type produced by KYOWA ELECTRONIC INSTRUMENTS CO., LTD.).
[Permeation Leakage Test]:
In a state where the O-ring was fitted to a leakage test apparatus and deformed by 25% by compression, the He leakage quantity was measured with the passage of time. The temperature condition was set at 100° C. At the same time as the measurement of the He leakage quantity, the distortion generated within the O-ring (i.e. inner stress) was measured by the pressure sensor which was embedded in the O-ring. Incidentally, as to the leakage test apparatus, the surface roughness of the sealed members that were placed on opposite sides of the O-ring was 3S.
The measurement results are shown in FIG. 11 . In FIG. 11 , the horizontal axis represents the inner stress alleviation ratio (%), and the vertical axis represents the leakage quantity. The inner stress alleviation ratio was calculated by the following equation.
Inner stress alleviation ratio (%)=[( F 0 −F t )/ F 0 ]×100
F 0 : inner stress measurement value at the fastening F t : inner stress measurement value at a passage of t hours
[Evaluation of Test Results]:
According to the test results, it was after about 1,200 hours from the start of the test that the sealing was judged bad from the He leakage quantity. At that point of time, the He leakage quantity had rapidly increased.
On the other hand, the inner stress alleviation ratio also increases gradually with the passage of time. When about 1,200 hours had passed, the inner stress alleviation ratio was 90%. It could be confirmed that: in the stage until the inner stress alleviation ratio reached 80%, the He leakage quantity was small and therefore the sufficient sealing function was fulfilled.
From this result, it can be understood that it will do that: at the stage when the inner stress alleviation ratio has exceeded 80%, the use of the O-ring is judged to be at the limit, and then the O-ring is exchanged. If the O-ring is exchanged at this stage, then there is no fear that the seal leakage from the O-ring occurs.
It has been demonstrated that: if the information detected by the pressure sensor embedded in the O-ring is transmitted to the pressure measurement apparatus (e.g. as set outside the device fitted with the O-ring) and thereby monitored, then it becomes possible to surely and accurately know the exchange timing of the O-ring.
Incidentally, in the aforementioned test, the inner stress alleviation ratio of 80% was judged to be the exchange timing of the O-ring. However, the value of the inner stress alleviation ratio, which is judged to be the exchange timing of the O-ring, is changed depending on such as material, size, structure, and fitting environment of the O-ring. If the value of the inner stress alleviation ratio, when the He leakage quantity exceeds the limit value, is determined by carrying out the same test as the aforementioned one in accordance with actual usage conditions, then the exchange timing of the O-ring can be decided accurately. In addition, depending on such as reliability upon the sealing function demanded under the fitting environment of the O-ring, a value obtained by allowing a prescribed safety ratio for the limit value of the inner stress alleviation ratio determined by the test may be judged to be the exchange timing of the O-ring.
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An object of the present invention is to make it possible to accurately and simply manage the performance deterioration and life duration of sealing rings and other various information about each sealing ring. As a means of achieving this object, a sealing ring according to the present invention is a sealing ring 30 to be fitted to a face-to-face part of members 12, 14 to thus seal a space between both members, comprising: a main body part 32 that is ring-shaped and is capable of becoming elastically deformed; and a circuit chip 40 that is attached unitedly to the main body part 32 and has an information-transmitting means 42 for transmitting the information with the outside of the sealing ring 30.
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This application is a continuation-in-part of patent application Ser. No. 919,550, filed Jul. 22, 1992, now abandoned.
FIELD OF THE INVENTION
The subject of the present invention is a flat-bed knitting machine comprising two knitting beds, at least one pair of opposed cam carriers for driving the needles, means for driving these cam carriers along the sections, a plurality of yarn guides capable of being displaced on bars above the sections, means for driving these yarn guides and means for controlling the displacements of the cam carriers and of the yarn guides.
PRIOR ART
Such a machine is known, for example, from Patent Application EP 0,246,364. In this machine, as in all the known machines, the cam carriers are mounted on a bow-shaped carriage straddling the sections and the striping bars on which the yarn guides are displaced. Such a form of carriage has been used practically since the invention of two-section knitting machines, and it has hitherto been considered an obligatory feature in order to ensure the synchronized displacement of the two cam carriers, despite its disadvantages where a machine for knitting intarsia fabrics is concerned. These disadvantages are that the yarns to be knitted have to be fed to the yarn guides almost horizontally so as not to be in the path of the carriage. To this effect, the yarns must pass over pulleys at one of the ends of the machine. The result of this is that, in one direction of displacement of the carriage, there is a pronounced pull on the yarn, while during the displacement of the carriage in the other direction the yarn has to be drawn back in the other direction so that the slack occurring in the yarn does not cause the yarn to fall onto the sections. These conditions, which have had to be satisfied hitherto, limit the displacement speed of the carriage and the number of yarns of different colors capable of being knitted. Now the current performances of the electronic and mechanical means are such that, without these disadvantages, it would be directly possible to work at a speed substantially higher than the current speed and with more yarns.
In the 1920s, Messrs. Dubied sought to solve this problem by lengthening the carriage bow transversely. The carriage bow extended in the prolongation of the machine, thus considerably increasing the bulk of the machine.
SUMMARY OF THE INVENTION
The object of the present invention is to overcome the abovedescribed disadvantages and to provide a construction making it possible to increase considerably the working speed of the machine and the number of yarns knitted.
The knitting machine according to the invention is defined in that the cam carriers of each pair are independent, and in that they are driven individually and are interdependent.
The knitting machine according to the invention therefore virtually no longer possesses a carriage, and, contrary to preconceived ideas, a synchronization of the cam carriers is perfectly possible without any rigid connection between these cam carriers.
The interdependence of the cam carriers can be ensured by mechanical or electronic means.
Hitherto, a carriage has also seemed necessary for ensuring the transverse alignment of the cam carriers. Now it transpires that the cam carriers do not necessarily have to be aligned transversely, but that it can, on the contrary, be expedient for them to be offset, for example in order to tighten or loosen the stitches, as desired. The knitting machine according to the invention indeed makes it possible to offset the cam carriers as desired. This capability affords tremendous knitting possibilities and gives a very high flexibility of use.
In such a knitting machine, the yarn guides are preferably driven individually, each by its own motor, thereby making it possible to position the yarn guides as desired and hence produce new stitch structures as well as the combination of different structures and intarsia.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying drawing shows one embodiment of the invention by way of example.
FIG. 1 shows diagrammatically a front view of a knitting machine.
FIG. 2 is a sectional view along II--II of FIG. 1, showing the mechanical means for interdependantly driving the cam carriers.
FIG. 3 is a schematic view of the control means of the machine of the FIG. 2.
FIG. 4 is a schematic view of the control means in a second embodiment with one single driving motor for both cam carriers.
FIG. 5 is a detail view of the phase shift mechanism used in the second embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The knitting machine shown comprises, in the same way as conventional machines, a stand 1 carrying two knitting beds 2 and 3 assembled in a V-shaped manner. Arranged in each of the knitting beds 2 and 3 are needles and jacks, the drive of which is ensured by two cam carriers 4 and 5, of the double-set type in the example under consideration.
In their new design, the cam carriers 4 and 5 are not mounted on a carriage, but are independent. The cam carrier 4 is mounted slideably on two parallel bars 6 and 7. Similarly, the cam carrier 5 is mounted on two cylindrical parallel bars 8 and 9. The cam carrier 4 is attached to a notched belt 10 extending over virtually the entire length of the machine. The notched belt 10 is driven by a gearwheel 11, itself driven by a first electric motor 12. Similarly, the cam carrier 5 is attached to a second notched belt 13 driven by a gearwheel 14, itself driven by a second motor 15. At the other end of the machine, the notched belts pass over pulleys 16. These pulleys can likewise be toothed. So as to have two completely identical notched belts 10 and 13, these belts are preferably obtained by dividing a notched belt lengthwise. The belts obtained are thus completely identical as regards both their shape and their structure. They therefore possess, in particular, the same elasticity characteristics. The motors 12, 15, the gear wheels 11, 14, belts 10, 13 constitute the drive means for the respective cam carriers 4, 5.
Above the knitting beds 2 and 3, a particular number of bars, in the example shown six bars 17, 18, 19, 20, 21, 22, extend parallel to the knitting beds and are carried at their ends by two columns 23 and 24. A yarn guide 25, 26, 27, 28, 29, 30 is mounted slideably on each of these bars 17 to 22, respectively. A yarn catcher, such as 31, is mounted on each yarn guide. Each yarn guide is driven along its bar by means of a small individual electric motor by the agency of a belt or an endless screw (not shown). The elimination of the carriage frees the entire space above the knitting beds, thus making it possible to arrange the bars of the yarn guides freely at the height and with the spacing most suitable for grasping and driving the yarns. It is also directly possible, moreover, to increase the number of bars, that is to say yarn guides, and consequently the number of different yarns capable of being knitted.
Located in a known way at the rear of the knitting beds is a package support 31', on which six packages, such as the package 32, are mounted. The packages have not been shown in FIG. 1. Yarn pulleys 33, 34, 35, 36, 37, 38 are mounted opposite each of the packages and above each corresponding yarn guide.
The two motors 12 and 15 are controlled by a control device 50 represented in detail in FIG. 3.
The control of two servomechanisms or more in dynamic automatic control of position is well known in the field of machine tools (shaping, drawing tables) and of robots. In this type of automatic control the trajectories are described in parametric time form. The controls of the motors are independent and of the position forecasting type with speed feed forward. This type of control can be used in the case of independent cam-carrying carriages as well as for thread-guiding carriages. Such an automatic control system is represented, for memory, in FIG. 3.
The motors 12 and 13 are brushless motors 5 equipped with a position encoder 52A, 52B respectively, and with a three-phase bridge. The motors 12 and 13 are driven by means of a driver 53A, 53B respectively.
A microprocessor 54A, 54B respectively,specialized in the control of the respective motor 12, 15. The motor 12 drives the carriage 4 by means of the toothed wheel 11 and the toothed belt 10. The position of the carriage 4 is detected by means of a magnetic sensor 57A. A reference position zero is fixed by means of a detector 58A. In an identical way, the carriage is driven by its toothed belt 13. It is equipped with a position sensor 57B.
The thread guides 25 to 30 are driven in the same way as the carriages-4 and 5 as indicated for the first thread guide 25 in FIG. 3.
All the microprocessors 54A, 54B, 54C, . . . are connected to a main processor 60 which sets out the control orders to be executed by the various drives. This processor 60 therefore receives the information coming from the magnetic sensors 57A, 57B associated with the carriages 4 and 5.
Before each movement of the carriages 4 and 5 the orders set out by the main processor 60, which orders contain the information necessary to calculate the position with time of these carriages, are sent to the various microprocessors 54A, 54B, 54C . . . On the basis of this information (acceleration, maximum speed, arrival point, starting time), each microprocessor sets out a theoretical position datum which the associated drive will follow over time. To this end, the microprocessor keeps the position of the drive up to date by counting the pulses from the incremental encoder 52A, 52B associated with the motor, compares this position with the datum generated and determines the order and duration of the activation of each phase of the motor.
Since each control is independent, it is therefore possible to produce an offset of one carriage relative to the other carriage. When the carriages are operating, that is to say when they are moving, they are, however controlled by identical datums in time in order to prevent different dynamic behaviors of the belts 10 and 13. The difference in original position will correspond to the phase difference. This phase difference is managed by the main processor 60 which can measure the actual phase of the carriages on the basis of the position of the needles which position is determined by the magneto resistive sensors 57A and 57B. It should be emphasized that these sensors already exist on the machines prior to the present invention for controlling knitting needles. Such a control technique is moreover well known to the person skilled in the art.
The main advantage of the knitting machine shown emerges at once from the drawing. It can be seen that the yarns 39 to 44 go toward each of the yarn guides along the shortest path. Let it be assumed that the cam carriers are displaced in the direction of the arrow. The yarn guides 26 and 30 are driven by their respective motors in synchronization with the displacement of the cam carriers and the yarns 40 and 44 are knitted. There is minimum tension on the yarn 40. To change yarns, it is sufficient to move the knitted yarn out of the path of the needles and to bring another yarn into this path by displacing its yarn guide in a suitable way, for example as described in Patent Application EP 0,415,512.
It becomes possible to work with yarns which are more fragile than current yarns. It is possible to increase considerably the number of bars and of yarn guides, for example to bring this number to twenty, thus making it possible to knit in twenty different colors.
The possibility of offsetting the cam carriers relative to one another as desired affords tremendous knitting possibilities. A small offset makes it possible to tighten or, on the contrary, enlarge stitches. A greater offset should make it possible to convert a single-set machine into a double-set machine. The possibilities afforded are immense.
It is possible to drive the two carriages 4 and 5 by means of a single motor which is common to both carriages. Such an embodiment will be described in relation to FIGS. 4 and 5. The common motor 51 is again a brushless motor controlled by a microprocessor 74 by means of a driver 53. The microprocessor 54 is again controlled via the main processor 60 of the knitting machine. The motor 51 is also equipped with a position encoder 52 and includes a shaft 59 with two outputs. On one side a toothed wheel 55 corresponding to the toothed wheel 11 is keyed onto the shaft 59 and directly drives the belt 10 of the carriage 4. On the other side the shaft 59 drives the toothed belt 13 of the second carriage 5 by means of a phase shifting device 70 controlled by a step by step motor or servomotor 80 controlled by the main processor 60 by means of a driver 81. The thread guides are controlled as before.
The phase shifting device 70 is represented in partial section in FIG. 5. The end of the shaft 59 has helical toothing 71 engaged partially in similar helical toothing of a cylindrical ring 72 mounted so that it can slide axially in a cylindrical sleeve 73 having a toothed part 74 intended to drive the toothed belt 13 of the carriage 5 and therefore corresponding to the toothed wheel 14 of FIG. 2. The sleeve 73 is mounted so that it can rotate on the shaft 59 by means of a double ball bearing 75. The ring 72 is made rotationally integral with the sleeve 73 by keying 76, so that the toothed sleeve 73 is driven by the shaft 59 by means of the ring 72. This ring 72 is furthermore thrust axially by a spring 77 against a thrust ball bearing 78 one of the races 78A of which is fixed to the end of a worm 79 driven by the stepper motor 80 which therefore has the effect of making the worm 79 advance or retract. The axial movement of the worm 79 has the effect of axially moving the ring 72. Due to the helical toothing 71, such an axial movement of the ring 72 has the effect of rotating it, and with it the toothed sleeve 73, and thus of introducing a mechanical phase shift between the sleeve 73 and the toothed wheel 55, that is to say between the toothed belts 10 and 13, that is to say a phase shift between the carriages 4 and 5. The main processor 60 receives the signals coming from the position sensors 57A and 57B associated with each carriage. It is therefore possible to verify whether the phase shift corresponds to the required value and if necessary to correct it by means of the motor 80. A control loop is thus produced. This control loop is characterized by a very low cut off frequency and can in no way compensate for the error in dynamic phase shift due to the deformation of the belts under the effect of the forces for accelerating and braking the carriages. The use of perfectly identical toothed belts obtained, as described above, by splitting a belt and producing identical stressing conditions for each of the belts, however, makes it possible to avoid these mechanical phase shift variations due to the deformations of the belts.
The cam carriers could be driven by other means, for example by means of an endless screw which could replace one of the guide bars.
Each bar could carry two yarn guides, namely one yarn guide on each side of the bar.
The technique described also applies, of course, to a double machine.
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The machine comprises two knitting beds (2, 3) and at least one pair of opposed cam carriers (4, 5). These cam carriers are independent and are driven individually, for example by notched belts (10, 13) and motors (12, 15). The elimination of the bow of the carriage makes it possible to provide a large number of bars (17 to 22) for yarn guides driven individually. The yarns arrive at the yarn guides along the shortest path, and the working speed can be increased considerably.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a national stage of PCT/EP08/057851 filed Jun. 20, 2008 and published in English, which has a priority of Denmark no. PA 2007 00892 filed Jun. 21, 2007, hereby incorporated by reference.
The present invention relates to a unit, a plant and a method for treatment of polluted water.
BACKGROUND OF THE INVENTION
1. Field of the Invention
During the latest decade there has been an increased focus on the purification of waste water from urban and industrial activity prior to leading it back to nature.
Numerous isolated private housings are still not connected to public sewerage systems and their waste water is therefore not treated in a public purifying plant. Instead these housings have to rely on their individual solutions to the purification issue.
A common solution for one-family houses is in form of a septic tank in which an anaerobic fermentation process at low temperatures purifies the waste water. This process however takes a significant time and the outflow is often discharged to some kind of percolation through the ground, e.g. a seepage pit, or through a drainage tube, e.g. to the nearest lake or stream.
In Denmark alone more than 300.000 housings only rely on a septic tank for waste water treatment.
Recent demands from the authorities force such housings to provide improved purification of their waste water. Among others there are focus on organic compounds, phosphorous compounds and nitrogen containing compounds.
In many areas in which it is not feasible to be connected to a public sewerage system it is an option to provide individual solutions which, however would give rise to provision of a total excess capacity of the plants especially for concentrations of users in a limited geographical area. A simple scaling up in a common plant of would also require installation of an excess capacity of septic tanks in order to meet with the required holding time in the septic tank, in order that the plant can handle peak flows.
Still further, in sparely populated or remote areas the infrastructure is often poorly developed which complicates establishment of local or remote plants due to lack of roads or other means of communication.
2. Description of the Related Art
Various mini purification plants have been proposed, e.g. plants of the kind disclosed in WO 03/020650 (Kongsted Maskinfabrik) or WO 2005/026064 (Biokube). Such plants are delivered in the form of a package solution comprising a tank for containing the functional parts together with an assembly of the functional parts which are then assembled at the site where the plant is to be placed.
WO 98/23540 discloses waste-water treatment system for biological cleaning of waste-water from one or more households, institutions, recreation centres, business premises and the like, and for up to approx. 50 person equivalents (PE), said treatment comprising aeration and biological filtration of the waste-water, nitrification and chemical precipitation of phosphor. The miniature waste-water treatment system is characterized in that the system comprises a container with a solid filter element and a post-clarification zone, the system has elements) to lead air in counterblow in relation to the waste-water, a pump controlled by a level switch is provided in a pump well mounted on the side of the container, a time-controlled pump is arranged to dose waste-water to a precipitation chemical, and the system has elements to lead sludge which, by the aeration and chemical precipitation is deposited in the bottom of the container, to a sedimentation tank which is placed upstream from the system.
The system is rather complicated and demands a constant control and supply of e.g. chemicals and maintenance of pumps not always being available at remote sites. Furthermore, the lowermost part of the container consists of a truncated cone, the smallest diameter of which is disposed at the bottom in the container, concentrating the precipitated sludge in the truncated cone which renders a system exposed for clogging. Still further the system disclosed in WO 98/23540 requires a bottom comprising a fundament with a strong flange which has a greater diameter than the container in order to safeguard the system against buoyancy.
For remote sites, however, the delivery of tanks and assembly of the state of the art is associated with disproportionately high transportation and erection costs. Furthermore, such plants should be simple and require a minimum of control and maintenance.
The present invention offers a simple and reliable solution to these problems.
SUMMARY OF THE INVENTION
The present invention relates to a unit comprising means necessary for performing waste water treatment, said unit comprising
a) a housing having walls and a level bottom defining a cylindrical chamber optionally having a top cover, said chamber being provided with at least one inlet for water to be treated and at least one outlet for treated water, said outlet being in the lower part of the cylindrical side walls of the chamber,
b) at least one bio filter placed in said chamber, said bio filter having a height shorter than the height of the side walls of the chamber and being positioned in the chamber in such a manner that a sludge collecting chamber having the same cross section as the chamber is formed in the cylindrical chamber below the bio filter,
c) at least one air distribution unit placed in said chamber between said bio filter and the bottom of the chamber, said air distributing unit being located so that all air is released below the bio filter,
d) at least one connection for connecting the inlet with an inlet conduit,
e) at least one connection for connecting the outlet with an outlet conduit,
f) at least one connection for a line for feeding compressed air to the air distribution unit, and
g) at least one connection for connecting to an external supply of electrical power.
In a second aspect the invention relates to a plant for treating water, said plant comprising a first vessel for accommodating at least one unit according to the invention and further comprising a second vessel for accumulating particulate material from the water to be treated before said water is fed to the unit, said second vessel being provided an inlet for water to be treated and at least one conduit for feeding water from the second vessel to the inlet connector of the unit, at least one conduit for connected to the outlet for carrying treated water, and at least one connector for supplying power to the compressor and/or pump.
In a third aspect the invention relates to a method for treating water comprising the steps:
a) feeding the water to a unit or plant according to the invention at a rate distributing the load on the unit evenly over a 24 hour period and
b) feeding power to the compressor for feeding air to the air distribution unit.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is disclosed more in detail with reference to the drawings in which
FIG. 1 shows an embodiment of a unit of the invention seen at an angle from above
FIG. 2 shows the embodiment of FIG. 1 in which two walls of the housing have been taken away, and
FIG. 3 shows the embodiment of FIG. 1 seen from above.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modification within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention relates to a unit for water treatment, said unit comprising the components necessary for performing waste water treatment, said unit comprising
a) a housing having walls and a level bottom defining a cylindrical chamber optionally having a top cover, said chamber being provided with at least one inlet for water to be treated and at least one outlet for treated water, said outlet being in the lower part of the cylindrical side walls of the chamber,
b) at least one bio filter placed in said chamber, said bio filter having a height shorter than the height of the side walls of the chamber and being positioned in the chamber in such a manner that a sludge collecting chamber having the same cross section as the chamber is formed in the cylindrical chamber below the bio filter,
c) at least one air distribution unit placed in said chamber between said bio filter and the bottom of the chamber, said air distributing unit being located so that all air is released below the bio filter,
d) at least one connection for connecting the inlet with an inlet conduit,
e) at least one connection for connecting the outlet with an outlet conduit,
f) at least one connection for a line for feeding compressed air to the air distribution unit, and
g) at least one connection for connecting to an external supply of electrical power.
The present invention further relates to a method for biological purification of polluted water and a plant for use in the method. In particular, a plant according to the invention is a purification plant of the type “submerged aerated bio filter plant”, and is characterized in that the plant is capable of handling varying amount of incoming water be by evening out the load on the plant. This is obtained by controlling the flow rate from a vessel or tank for accumulation of particulate material to the unit(s) according to the invention, e.g. using a pump delivering a uniform feeding stream to the unit.
The invention is based on the idea of providing a unit comprising all functional parts needed for the treatment of waste water, which unit is then placed in a tank which may be produced locally from materials being locally available and be provided with a source of electrical power and a source of compressed air.
The functional parts will be manufactured and assembled to a unit according to the invention which is ready to be set up at the desired site in a simple tank with a level bottom and to be connected to a power supply and supply of water to be treated and to conducts for carrying treated water and optionally a compressor unit.
A tank for use together with units according to the invention may in a most simple embodiment be in the form of a pit or niche in the ground provided with a level bottom or a tank erected from concrete or other material being locally available or from prefabricated parts for assembling a tank. Such prefabricated parts are preferably lightweight parts produced locally from materials locally available. The purpose of the tank is to accommodate a unit of the invention and to ensure a constant level of water in a plant comprising such unit, suitably by providing the tank with an overflow pipe. Furthermore, the tank may have a size allowing it to serve as a reservoir for settled sludge for reducing the frequency of removal of sludge and maintenance
Thus, no voluminous tank has to be delivered at a remote site and the transport and delivery of the unit which is ready to set up and be connected to the connections needed may be effected using smaller and light trucks or even helicopters.
It has been found that the present invention renders it simple and cheap to establish purification of water in small scale at remote locations, where needed and thus provides a suitable solution to the problem of improving the quality of waste water and to reduce the adverse effects thereof in nature at remote locations where it may be difficult to establish a conventional purification plant.
In a unit according to the invention particles and sludge are simply deposited in the bottom thereof.
In one embodiment the unit is provided with pumping means in the form of an air lift pump for removing deposited matter from the bottom thereof.
Settling is ensured by dimensioning the units with the bio filters in consideration of the amount of water to be treated to obtain a residence time of water in the unit being longer than the time used for a predetermined fraction e.g. ½, ⅔, ¾, ⅘, 9/10 or 99/100 of the solid matter to sink from the top to the bottom of the unit to form a sediment.
In one embodiment of the invention the unit of the invention may e.g. be used as such by placing one or more units forming individual water treatment plants in a lake or stream or fjord or firth for purifying and aerating the water. Air fed to the air distributing unit below the bio filter which ensures circulation of the air and water to be treated through the filter so that contact is established between the water to be treated and the bacteria in the bio film on the filter surfaces whereby organic matter is decomposed and nitrogen compounds are converted, and the water become aerated increasing the content of oxygen.
In a preferred embodiment a unit according to the invention further comprises a compressor unit connected to the line for feeding air to the diffuser providing a unit only needing an external source of electrical power to be operated.
The housing of the unit may be made from materials such as metal, concrete or preferably fibre reinforced materials such as glass fibre reinforced polyester or from a plastics material for reducing the weight of the unit.
In a preferred embodiment a plastics material such as a polyolefin such as polyethylene or polypropylene or polyvinyl chloride is used.
The housing of a unit of the invention is preferably box-shaped and preferably has a square cross section seen from above. However, the unit may have other generally cylindrical shapes having circular or rectangular cross sections.
In one embodiment of the invention the bio filter is positioned in the chamber in such a manner that a fluid distribution space is formed in the chamber on top of the filter and at the least one inlet of the unit is in the form of at least one hole located at a distance from the top of the chamber walls and communicating with said space giving a simple construction.
Typically, the outlet in the side of the chamber walls has a large dimension in order to ensure a sufficiently low flow rate of water from the sludge collecting chamber to allow settling of sludge for avoiding that the sludge is carried with the treated water to the recipient. Furthermore, a large dimension of the outlet allows for using the tank of a plant according to the invention for collecting sludge minimizes the risk of clogging, and in case of a sudden high amount of incoming water and also renders it possible to run a plant without a pump for removing sludge which may simply be removed mechanically. In one embodiment of the invention the dimensions of the outlet corresponds to the size of a side of the sludge collecting chamber. This also enables a simple mechanical removal of sludge, if needed.
The sludge collecting chamber located below the bio filter in accordance with the invention reduces the risk of clogging and simplifies the running of a plant comprising the unit as stated above.
The at least one bio filter is preferably mounted in a vertical position as compared to the bottom of the housing of the unit.
It is preferred to use a bio filter which is not blocked or which does not reduce efficacy when bacteria grow thereon as would be the case when using pipes or tubing's. Suitable filter materials are e.g. tubes spun from plastic strings or filter materials available as Bioblok filter materials. In a preferred embodiment the bio filter used in the present invention is a Bioblok filter such as Bioblok 100 having a surface area of 100 m 2 /m 3 or a Bioblok 150 having a surface area of 150 m 2 /m 3.
The air distribution unit may be any unit from which air can be released in the form of small bubbles evenly distributed across the bottom area of the filter and is preferably a diffuser.
Typically, the diffuser delivers an amount of air of between 10 and 100 liters of air per 100 liters of vessel volume per minute.
A unit according to the invention is preferably provided with a controlling unit for controlling the rate of feeding water to the unit in a manner known per se for distributing the load on the unit evenly over a 24 hour period.
In a second aspect the invention relates to a plant for treating water, said plant comprising a first vessel for accommodating at least one unit according to the invention and further comprising a second vessel for accumulating particulate material from the water to be treated before said water is fed to the unit, said second vessel being provided an inlet for water to be treated and at least one conduit for feeding water from the second vessel to the inlet connector of the unit, at least one conduit for connected to the outlet for carrying treated water, and at least one connector for supplying power to the compressor and/or pump.
It is preferred that the inlet of a unit according to the invention is at the same level as a conduit for feeding water to the plant which eliminates the need of a pump for feeding water to the unit and renders a plant of the invention less exposed for stoppage of the function of such a plant.
A plant according to the invention may comprise from 1 to 12 units according to the invention placed in individual tanks working in series or in parallel or alternatively in a common tank.
When the units are placed in series, the partially purified waste water exiting from a first unit is passed on to a second unit and so forth giving rise to a further purification.
Less polluted water may be purified using units in parallel increasing the capacity of the plant.
Thus, a plant according to the invention may be in the form of a long and narrow plant, or a shorter but more compact plant. What are decisive for the purification capacity are the cubic capacity of the filter elements and the aeration and the interrelationship of the units as stated above.
The treated water is then discharged to the recipient via the outlet.
In a further embodiment the plant comprises from 3 to 12 units according to the invention if planned for use in connection with a minor settlement.
A plant being composed of several separate units in which each unit is separately replaceable, enables a construction, in which it is possible in a simple and easy way, to replace individual parts of the plant, or to extend the plant by adding more units, should the need arise, for example, for providing increased capacity in case of an increasing amount of water to be treated. The advantages of this are evident.
According to a particularly preferred embodiment, the plant is a small purification plant of the kind provided with a submerged aerated bio filter, such plant preferably having a capacity of treating between 10 and 150 cubic meters of water per day.
A typical volume of a unit or a section for use in connection with the preferred small plant will be between 3 m 3 and 40 m 3 . The interior of the tank of a plant of the invention can, if desired, be divided into a purification portion occupied by units according to the invention and a settling portion by means of a partitioning wall which does not reach all the way to the bottom of the tank.
A plant according to the invention is preferably provided with a controlling unit for controlling the rate of feeding water to the unit in a manner known per se for distributing the load on the unit evenly over a 24 hour period, e.g. by controlling the output of a feeding pump.
In a further embodiment of the invention one or more units according to the invention may be used for providing a plant for purifying a brook, a stream, a feeder or small river. This may especially be of interest in areas in which settlements at the upper course of a brook or the like utilises the same for the discharge of waste water and settlements further downstream uses the same brook or the like as source for drinking water. It its most simple embodiment, a barrage is established and the stream of water led through one or more units according to the invention for purification of the water which units suitably may be incorporated as a part of such a barrage.
In a third aspect the invention relates to a method for treating water comprising the steps:
a) feeding the water to a unit according to the invention or a plant according to the invention at a rate distributing the load on the unit evenly over a 24 hour period and
b) feeding power to the compressor for feeding air to the air distribution unit.
In a preferred embodiment, the control of the process is constructed and controlled in such manner that the day load on the plant is distributed evenly over all the 24 hours of the day.
By controlling the flow of polluted water through the plant over the time, the polluted water can be passed through the plant evenly distributed over the entire day and hereby provide optimal living conditions for the micro organisms. Optimal bacteria growth conditions result in a more efficient purification, which again gives a reduction of the overcapacity which would else be necessary.
It has surprisingly and unexpectedly been found that by the method according to the invention in which the a time wise proportional load on the plant, outlet analysis results are obtained that are significantly below the requirements which the authorities place on far larger and much more advanced systems.
It is preferred to ensure an even load of the plant by using an electronically controlled pump for controlling the stream of water to the unit or plant.
In an especially preferred embodiment the water flows though the biodegrading zone at such a rate that settlement occurs in the biodegrading zone. A suitable rate can be determined by first determining the averaged settle rate of the particles in the water and then adjusting the flow rate such that the water remains in the zone longer than it takes for an average particle to sink from the top of the zone to the bottom. The settlement can settle any desired fraction of the particles by adjusting the flow rate of water to settle rate for the desire fraction. However the necessary feed to the bacteria also has to be taken into account.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is now explained more in detail with reference to the drawings showing preferred embodiments of the invention.
Reference is made to FIGS. 1 and 2 of the drawings showing an embodiment of a unit according to the invention.
A unit 1 for water treatment comprises
a) a housing having walls 2 and a bottom 3 defining a chamber optionally having a top cover, said chamber being provided with at least one inlet 4 ,
b) at least one bio filter 5 placed in said chamber,
c) at least one air distribution unit 6 placed in said chamber between said bio filter 5 and the bottom 3 of the chamber and being provided with a line 7 for feeding air to the diffuser, and
d) at least one inlet 4 ,
e) at least one outlet 8 .
Furthermore such a unit is provided with at least one connection for a line for feeding compressed air to the air distribution unit, and at least one connection for connecting to an external supply of electrical power.
FIG. 3 shows the unit shown in FIG. 1 seen from above.
A unit or a plant according to the invention may be made in a manner known per se by the skilled in the art after deciding on the materials to be used for a specific embodiment of the invention.
The invention being thus described, it will be apparent that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be recognized by one skilled in the art are intended to be included within the scope of the following claims.
SUMMARY LISTING OF REFERENCES
WO 03/020650 A1 (Kongsted Maskinfabrik) 13 Mar. 2003
US 2004/0173524 A1 (Kongsted Maskinfabrik) 9 Sep. 2004
WO 2005/026064 A1 (Biokube) 24 Mar. 2005
US 2007/0108124 A1 (Biokube) 17 May 2007
WO 98/23540 A1 (Ferdinand Joergen Marcus) 4 Jun. 1998
U.S. Pat. No. 6,217,761 B1 (Catanzaro et al.) 17 Apr. 2001
GB 2355712 A (Mate Stehpen Ferenc et al.) 2 May 2001
DE 19945985 A1 (Ammermann GmbH) 29 Mar. 2001
WO 03/027030 A1 (Hepworth Building Products Limited) 3 Apr. 2003
U.S. Pat. No. 5,707,513 A (Jowett E Craig at al.) 13 Jan. 1998
US 2003/0132148 A1 (Okamoto Ryoichi et al.) 17 Jul. 2003
EP 1 484 287 A (University of Santiago Compostella) 8 Dec. 2004
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A unit for performing waste water treatment provides a simple and inexpensive approach to purifying water on a small scale at remote locations.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to amplifiers, and more particularly relates to a nonlinear transconductance amplifier for improving a response time of the amplifier to widely varying load conditions.
BACKGROUND OF THE INVENTION
[0002] In certain applications employing an amplifier, the load conditions experienced by the amplifier can often change significantly and abruptly. Conventional amplifiers experiencing widely varying load conditions typically utilize a large compensation capacitor coupled to the output of the amplifier in order to stabilize the amplifier over a wide range of output loads that may be encountered. Due to the size of the compensation capacitor that is required, however, the response time of the amplifier is significantly reduced. One such application in which load conditions can change rapidly is in a hard disk drive preamplifier system, which generally requires a low loop bandwidth for undistorted data recovery and fast settling time to meet write-to-read mode transition specifications.
[0003] Present hard disk drive system specifications require fast mode changes, for example, from a write mode to a read mode on the order of about 200 nanoseconds (ns) or less. In the read mode, the bias loop time constant should be greater than 100 microseconds (μs). In the write mode, large write signals may couple through read and write heads and through interconnects between the heads and the disk drive preamplifier. The coupled write mode signal amplitude can be much higher than the read mode signal. Thus, the parasitic coupling between write and read signal paths drives the read path direct current (dc) bias points far from their normal quiescent operating points during the write mode. Consequently, when the preamplifier transitions from write to read mode, the read bias loop sees a large error signal.
[0004] To simultaneously meet fast write-to-read mode transition requirements while providing low loop bandwidth during the read mode, a timing circuit 104 has been used in conjunction with an operational amplifier 102 , as is shown in FIG. 1. In this manner, the transconductance of the amplifier 102 in the bias loop is increased by switching a large current to the amplifier for a predetermined period when changing from write mode to read mode. In U.S. Pat. No. 5,940,235 to Sasaki et al., a reproducing circuit for a magnetic head uses exponential current amplification without employing timing circuitry. Some of the drawbacks to this circuit arrangement, however, include difficulty in controlling the slope of the output current and a threshold range of the amplifier, as well as providing a very narrow threshold range. The threshold range is the region in which the output current is essentially zero (or very small) for an input differential voltage that is close to zero. Outside this threshold range, the transconductance (i.e., output-current-to-input-voltage ratio) relation is an exponential function. If the threshold range is narrow, the read mode bias loop will be undesirably affected by a normal read signal and the amplifier will possess a loop bandwidth that is too large.
[0005] U.S. Pat. No. 6,181,203 to Newlin discloses a nonlinear transconductance amplifier which has an output transfer characteristic that exhibits two different nonlinear relationships depending on the input differential signal level applied to the amplifier. The amplifier requires a dual differential pair of input bipolar devices and a corresponding bipolar current mirror for each of the four input devices. Consequently, the amplifier requires substantial area on a silicon wafer and dissipates a significant amount of quiescent current. A pair of emitter degeneration resistors in two of the four current mirrors, in conjunction with a pair of emitter degeneration resistors associated with the dual differential input devices, provide control over the knee point at which the two nonlinear relationships switch. However, due at least in part to the number of resistive elements affecting this knee point, accurately setting the knee point of the amplifier can be quite difficult to accomplish. Moreover, this circuit configuration may be susceptible to temperature and process variations.
[0006] Accordingly, there exists a need for an amplifier circuit having an improved response time to widely varying load conditions, without employing timing circuitry. Moreover, it would be desirable to provide an amplifier having reduced quiescent current dissipation and improved stability over temperature and process variations.
SUMMARY OF THE INVENTION
[0007] The present invention provides an improved amplifier which simultaneously meets fast write-to-read mode transition requirements while possessing a low loop bandwidth for undistorted data recovery. Furthermore, the amplifier of the present invention accomplishes these advantages without employing timing circuitry and the necessary overhead and/or noise often associated with such circuitry. The amplifier exhibits a transconductance that is substantially zero or linear when an input differential voltage presented to the amplifier is zero or small and a transconductance that is large or nonlinear for comparatively large input signals. A threshold region where the output of the amplifier is substantially zero can be easily set and tightly controlled by adjusting a single circuit element.
[0008] In accordance with one aspect of the invention, an exponential transconductance amplifier includes a linear differential input stage and a nonlinear transconductance stage operatively coupled to the differential input stage. The differential input stage includes first and second inputs forming a non-inverting input and an inverting input, respectively, of the amplifier for receiving an input differential signal. The nonlinear transconductance stage generates an output of the amplifier that exhibits a linear transconductance which is substantially zero or linear when the input differential signal is within a predetermined range and exhibits a large nonlinear transconductance when the input differential signal is outside the predetermined range. In accordance with another aspect of the invention, the nonlinear transconductance amplifier includes temperature compensation circuitry for providing a threshold region that is substantially constant over a predetermined temperature range of operation.
[0009] These and other features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a block diagram illustrating a conventional amplifier arrangement employing a timer circuit.
[0011] [0011]FIG. 2 is a block diagram illustrating a nonlinear transconductance amplifier, formed in accordance with one aspect of the present invention.
[0012] [0012]FIG. 3 is a schematic diagram illustrating an exemplary exponential transconductance amplifier, formed in accordance with the present invention.
[0013] [0013]FIG. 4 is a schematic diagram illustrating the exponential transconductance circuit of FIG. 3 including a temperature compensation circuit, formed in accordance with the present invention.
[0014] FIGS. 5 A- 5 C are graphical representations illustrating output current verses input voltage for the amplifier depicted in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] [0015]FIG. 2 depicts a block diagram of an amplifier 200 , formed in accordance with one aspect of the present invention. The amplifier 200 includes an input IN coupled to a non-linear large transconductance (g m ) circuit 202 and a linear low transconductance circuit 204 . Preferably, the input IN is a differential input, although a single-ended input is similarly contemplated by the present invention. An output 208 of the non-linear large transconductance circuit 202 is summed together with an output 210 of the linear low transconductance circuit 204 at a summing node 206 to form a combined output OUT of the amplifier 200 . It is to be appreciated that the linear low transconductance circuit 204 may be implemented using a conventional amplifier or transconductance stage, as understood by those skilled in the art. Consequently, a detailed explanation of the linear low transconductance circuit 204 will not be presented herein.
[0016] [0016]FIGS. 5A through 5C illustrate exemplary graphical representations of three outputs of the amplifier 200 of FIG. 2 with respect to an input differential voltage (VIN) applied to the amplifier 200 , in accordance with the present invention. FIG. 5A corresponds to the net output OUT of the amplifier 200 , FIG. 5B corresponds to the output 210 of the linear low transconductance circuit 204 , and FIG. 5C corresponds to the output 208 of the non-linear transconductance circuit 202 .
[0017] When an input signal applied to the input IN of amplifier 200 is small (e.g., ±20 millivolts (mV)), the amplifier output OUT exhibits a linear low transconductance, primarily resulting from the output 210 of the linear low transconductance circuit 204 . This is depicted by the linear portion 502 on the graphical representation of output current verses input voltage illustrated in FIG. 5A. Moreover, when the input signal applied to the amplifier 200 is large (e.g., ±200 mV), the amplifier output OUT exhibits a non-linear large transconductance. This is depicted by the non-linear portions 504 on the graphical representation of FIG. 5A. In accordance with the present invention, a threshold region wherein an output current from the output 208 of the non-linear large transconductance circuit 202 is substantially zero can be precisely adjusted and controlled over temperature and process variations. The operation of the non-linear large transconductance circuit 202 of amplifier 200 will be described in detail herein below in conjunction with an illustrative exponential transconductance amplifier.
[0018] With reference now to FIG. 3, an exemplary exponential transconductance amplifier 300 is shown, formed in accordance with the present invention. The illustrative exponential transconductance amplifier 300 includes a positive or non-inverting input VRP, a negative or inverting input VRN and an output IO, preferably in the form of a current. It is to be appreciated that a current output may be easily converted to a voltage output by including a current-to-voltage converter circuit, which may be a simple resistor (not shown), operatively coupled to the output of the amplifier, as understood by those skilled in the art. Thus, the illustrative exponential transconductance amplifier 300 may be considered a differential input amplifier. Although the amplifier 300 is shown using n-type metal-oxide-semiconductor (NMOS) and p-type metal-oxide-semiconductor (PMOS) transistor devices and npn and pnp bipolar junction transistor (BJT) devices, the present invention contemplates that one or more transistors may be replaced by other suitable alternative device types. Moreover, the transconductance amplifier 300 may be implemented using a complementary circuit architecture (e.g., n-type devices replaced by p-type devices, and vice versa) in a similar manner.
[0019] In accordance with the present invention, the exemplary exponential transconductance amplifier 300 includes a differential input stage and a non-linear transconductance stage operatively coupled to the differential input stage. The differential input stage comprises a pair of pnp input transistors Q 1 and Q 2 , each of the transistors Q 1 , Q 2 including an emitter terminal (E), a base terminal (B), and a collector terminal (C). As previously stated, although input transistors Q 1 , Q 2 are depicted as bipolar devices, these transistors maybe implemented using other suitable alternative devices, such as, for example, PMOS transistor devices, as understood by those skilled in the art.
[0020] Transistors Q 1 and Q 2 are substantially matched (e.g., size, shape, etc.) at least in part to reduce the effect of offset. The emitter terminals of transistors Q 1 and Q 2 are coupled together at node 308 , thus transistors Q 1 , Q 2 may be considered to be in a common-emitter configuration. A bias circuit 306 is operatively coupled between the common-emitter junction at node 308 and a positive voltage supply, VCC, and provides a bias current for biasing the amplifier 300 to a stable direct current (DC) quiescent operating point. The bias circuit 306 is shown as a constant current source I 1 , although it is to be appreciated that the bias circuit may be implemented, for example, as a simple resistor or it may be an active device, such as a transistor coupled to an appropriate bias voltage source (not shown), as understood by those skilled in the art. The base terminals of transistors Q 1 and Q 2 form the differential inputs VRP and VRN, respectively, of the amplifier 300 .
[0021] With continued reference to FIG. 3, the non-linear transconductance stage is preferably implemented as an exponential transconductance stage 302 coupled to the collector terminals of input transistors Q 1 , Q 2 for operatively controlling an output current of the amplifier. The exponential transconductance stage 302 is configured such that at relatively small input signal levels (e.g., +20 mV), the output current through the output IO of amplifier 300 will be substantially zero and at relatively large input signal levels (e.g., +200 mV), the output current will increase exponentially in response to a linear input signal applied to the amplifier 300 . In addition to providing control over the output current of the amplifier, exponential transconductance stage 302 provides a load for input transistors Q 1 and Q 2 .
[0022] The predetermined differential input voltage range V IN (e.g., |V IN |≦90 mV) wherein the output current through output IO of amplifier 300 is essentially zero is defined herein as the threshold region of the amplifier. In accordance with the present invention, the threshold region of amplifier 300 maybe selectively adjusted and tightly controlled by the exponential transconductance stage 302 , as will be explained in further detail herein below. This threshold region is represented as the horizontal portion 520 on the curve depicted in FIG. 5C. Threshold region knees or endpoints 522 on the curve of FIG. 5C refer to the points at which an absolute value of the output current through the output IO of amplifier 300 begins to increase exponentially for a given linear differential input voltage (e.g., |V IN |>90 mV) applied to the amplifier.
[0023] The exponential transconductance stage 302 is comprised of NMOS transistors M 1 through M 4 , each of the transistors M 1 through M 4 having a drain terminal (D), a gate terminal (G) and a source terminal (S). The exponential transconductance stage 302 further includes npn bipolar transistors Q 3 and Q 4 , each having an emitter terminal (E), a base terminal (B), and a collector terminal (C). Transistors Q 3 and Q 4 provide the necessary exponential transconductance for circuit 302 by virtue of the inherent exponential relationship between the collector current (I C ) of a bipolar transistor to its base-emitter voltage (V BE ), which may be expressed as
I C = I S · exp V BE V T , [ 1 ]
[0024] where I S is a constant (saturation current) used to describe the transfer characteristic of the transistor in the forward-active region (typically on the order of 10 −14 to 10 −15 Amperes), V BE is the base-emitter voltage of the transistor and V T is the thermal voltage of the transistor (typically about 26 millivolts at 300 degrees Kelvin). It is to be appreciated that, in accordance with the present invention, transistors Q 3 and Q 4 may be replaced by suitable alternative devices or circuits for providing other non-linear transconductance characteristics in the non-linear large transconductance circuit 202 depicted in FIG. 2.
[0025] Preferably, transistors M 1 , M 3 and Q 4 associated with the inverting (VRN) input side of the amplifier 300 are closely matched to corresponding transistors M 4 , M 2 and Q 3 , respectively, associated with the non-inverting (VRP) input side of the amplifier. Additionally, the sizes of transistors M 1 through M 4 , generally expressed as a ratio (W/L) of the width (W) of the particular transistor device to its length (L), are appropriately selected so that bipolar transistors Q 3 and Q 4 are biased at a desired operating point. To further provide accurate temperature tracking, corresponding components in the amplifier 300 may be placed in close relative proximity to one another on a semiconductor die.
[0026] With continued reference to FIG. 3, transistors M 1 and M 4 are each preferably connected in a diode configuration (i.e., the gate terminal of the transistor being coupled to its drain terminal). Transistors M 1 and M 4 essentially function, at least in part, as voltage level shifters for biasing transistors Q 3 and Q 4 to a predetermined quiescent operating point. Consequently, it is to be appreciated that transistors M 1 and M 4 may, instead, be configured with their gate terminals coupled to an appropriate corresponding bias voltage source (not shown), as understood by those skilled in the art. The drain and gate terminals of transistor M 4 are coupled to the collector terminal of transistor Q 1 at node 312 . Likewise, the drain and gate terminals of transistor M 1 are coupled to the collector terminal of transistor Q 2 at node 310 . The source terminals of transistors M 1 and M 4 are coupled to the drain terminals of transistors M 3 and M 2 at nodes 314 and 316 , respectively.
[0027] Transistors M 2 and M 3 may be considered load devices for the differential input stage comprised of transistors Q 1 and Q 2 . Transistors M 2 and M 3 are arranged so that the gate terminals of each transistor are connected to nodes on opposite sides of amplifier 300 in a cross-coupled arrangement. Specifically, the gate terminal of transistor M 2 is coupled to the gate terminal of transistor M 1 at node 310 and the gate terminal of transistor M 3 is coupled to the gate terminal of transistor M 4 at node 312 . The source terminals of transistors M 2 and M 3 are coupled to a negative voltage supply, which is preferably ground (GND) as shown.
[0028] The base terminals of transistors Q 3 and Q 4 , which, as previously described, provide the exponential transconductance characteristic of the amplifier 300 , are coupled to nodes 316 and 314 , respectively. The emitter terminals of transistors Q 3 and Q 4 are connected to ground. A resistor R 1 coupled between nodes 314 and 316 is preferably employed to linearize the base voltage seen by transistors Q 3 and Q 4 . Without resistor R 1 present, the voltage at the base terminals of transistors Q 3 , Q 4 would increase sharply with slight changes in the differential input signal level applied to the amplifier 300 , as will be discussed in more detail below. The value of resistor R 1 may be selected to control a slope of the linear voltage seen at the base terminals of transistors Q 3 and Q 4 , thus controlling the threshold region of the amplifier 300 . As the value of resistor R 1 is increased, the threshold region of the amplifier increases proportionally. Since the current that flows through resistor R 1 is bidirectional, only a single circuit element is required to adjust the threshold region of the amplifier.
[0029] The collector terminal of transistor Q 3 forms the output IO of the exponential transconductance amplifier 300 . The amplifier 300 preferably includes a cascode current mirror functioning as a load operatively coupled to the collector terminals of transistors Q 3 and Q 4 . The cascode current mirror comprises PMOS transistors M 5 through M 8 . Transistors M 5 and M 8 are coupled togther in a stacked (cascode) arrangement, with the drain terminal of transistor M 5 coupled to the source terminal of transistor M 8 . Likewise, transistors M 6 and M 7 are coupled togther in a stacked arrangement, with the drain terminal of transistor M 6 coupled to the source terminal of transistor M 7 . Furthermore, transistors M 5 and M 8 are each connected in a diode configuration. The drain terminal of transistor M 8 is coupled to the collector of transistor Q 4 and the source terminal of transistor M 5 coupled to the positive voltage supply, VCC. Likewise, the drain terminal of transistor M 7 is coupled to the collector terminal of transistor Q 3 and the source terminal of transistor M 6 is coupled to VCC. The gate terminals of transistors M 6 and M 7 are coupled to the gate terminals of transistors M 5 and M 8 at nodes 318 and 320 , respectively.
[0030] Assuming an emitter area scale factor of one (1) for each of the bipolar transistors Q 3 and Q 4 , the sizes of the cascode mirror transistors M 5 through M 8 are chosen to be ideally equal. However, the present invention contemplates that transistors M 6 and M 7 may be scaled by any predetermined factor n in comparison to corresponding transistors M 5 and M 8 , respectively, to produce a current through transistors M 6 , M 7 that is n times greater than the current in transistors M 5 , M 8 , where n is a number greater than zero. In this instance, bipolar transistors Q 3 and Q 4 will be sized such that transistor Q 3 has an emitter area that is n times greater than transistor Q 4 to provide proper current balancing, as appreciated by those skilled in the art. By way of example only, if transistors M 6 and M 7 are sized such that their W/L ratios are twice that of transistors M 5 and M 8 , respectively, transistor Q 3 will be sized to have an emitter area which is twice that of transistor Q 3 .
[0031] As previously stated, the load for transistors Q 3 and Q 4 is preferably a cascode current mirror which replicates the collector current of transistor Q 4 and operatively combines this current with the collector current of transistor Q 3 at output node IO to generate the output current of the amplifier 300 . The cascode load is preferred, at least in part, since this configuration desensitizes the effect of load impedance at the output IO of amplifier 300 . As shown in FIG. 3, the amplifier output IO is a single-ended output. It is to be appreciated, however, that the amplifier 300 may be easily modified to provide a differential output, for example, by eliminating the diode connection of transistors M 5 and M 8 and instead connecting the gate terminals of these transistors to a corresponding bias voltage source (not shown). The collector terminal of transistor Q 4 may then be used to form a complementary output of the amplifier 300 .
[0032] Exemplary sizes for each of the transistors, as well as other components in the amplifier 300 , are presented in Table 1 below for a conventional 0.8 micron (μm) bipolar-complementary metal-oxide-semiconductor (BiCMOS) fabrication process. For bipolar transistors Q 1 through Q 4 , the area scale factor is preferably equal to one. It is to be appreciated, however, that the present invention is not to be limited to these specific sizes or to the type of fabrication process employed, but that other sizes and alternative circuit fabrication processes may be utilized in accordance with the techniques of the present invention as set forth herein.
TABLE 1 Component Reference Name Size/Value M1 6.0 μm/0.8 μm M2 6.0 μm/2.0 μm M3 6.0 μm/2.0 μm M4 6.0 μm/0.8 μm M5 24.0 μm/0.8 μm M6 24.0 μm/0.8 μm M7 24.0 μm/0.8 μm M8 24.0 μm/0.8 μm R1 3.756K Ohms
[0033] With continued reference to FIG. 3, the operation of the illustrative exponential transconductance amplifier 300 will now be described. When a differential input voltage applied across inputs VRP and VRN of the amplifier 300 is zero, the current flowing out of the collector terminal of transistors Q 1 and Q 2 will be ideally equal. In practice, certain factors, such as, for example, fabrication process variations and localized temperature gradients, may cause device mismatches in the amplifier which can result in a small offset between the collector currents of transistors Q 1 and Q 2 .
[0034] Assuming symmetry in the differential input stage of amplifier 300 , since the collector currents of transistors Q 1 and Q 2 will be substantially equal to each other and the base-emitter voltages of the two transistors will be equal, as previously stated, the voltages at the collector terminals of the transistors Q 1 , Q 2 at nodes 310 and 312 , and thus the gate voltages of transistors M 3 and M 2 , respectively, will also be substantially equal to each other. At this operating point, the gate voltage of transistors M 3 and M 2 will be higher than the drain voltage of transistors M 3 and M 2 at nodes 314 , 316 , respectively, by an amount substantially equal to the gate-source voltage of transistors M 1 and M 4 . Consequently, both transistors M 3 and M 2 will be operating in a linear region. As appreciated by those skilled in the art, a MOS transistor operating in the linear region exhibits a relatively low output impedance.
[0035] Transistors M 1 through M 4 are preferably sized such that a voltage present at nodes 314 and 316 will be low enough (e.g., less than about 0.5 volt) to prevent transistors Q 4 and Q 3 , respectively, from turning on. As understood by those skilled in the art, knowing the drain current, i D , flowing in a given MOS transistor, approximate sizes for each of the MOS transistors can be determined for a desired gate-source voltage (V GS ) for the transistor using, for example, the expression
i D = K ′ ( W eff 2 L eff ) ( V GS - V T ) 2 , [ 2 ]
[0036] where W eff and L eff are the effective width and length, respectively, of the transistor device, K′ is the intrinsic transconductance parameter (in amperes/volt 2 ) based on the electron mobility and oxide thickness associated with the particular semiconductor fabrication process employed, and V T is the threshold voltage for the transistor. With transistors Q 3 and Q 4 off, amplifier 300 will be biased such that the collector current of transistors Q 3 and Q 4 will be substantially zero, and therefore the current flowing through the output IO of amplifier 300 will be substantially zero.
[0037] With the voltage at input terminal VRP of amplifier 300 held constant, as the voltage at input terminal VRN is increased (i.e., the emitter-base voltage of transistor Q 1 is greater than that of transistor Q 2 ), the collector current flowing through transistor Q 1 increases while the collector current in transistor Q 2 decreases. This will cause the gate voltage of transistor M 3 to increase while the available drain current in transistor M 3 , which will be substantially the same as the collector current of transistor Q 2 , decreases, thereby moving the operating point of transistor M 3 further into the linear region. The output impedance of transistor M 3 thus decreases causing the base voltage of transistor Q 4 to decrease toward zero, further preventing transistor Q 4 from turning on. Concurrently, the gate voltage of transistor M 2 will decrease, thus causing transistor M 2 to turn off. As transistor M 2 turns off, its output impedance will increase. With an increased collector current from transistor Q 1 and the increased output impedance of transistor M 2 , the drain voltage of transistor M 2 at node 316 will increase. This in turn will cause the base voltage of transistor Q 3 to increase, thus turning on transistor Q 3 .
[0038] Without resistor R 1 present, the base voltage of transistor Q 3 will increase sharply, thereby causing transistor Q 3 to sink a large output current. As previously stated, by adding resistor R 1 connected between the base terminals of transistors Q 4 and Q 3 (i.e., across nodes 314 and 316 ), the voltage at the base terminal of transistor Q 3 increases more linearly. In accordance with equation [1] above, a linear increase in base voltage, and therefore base-emitter voltage, of transistor Q 3 results in an exponential increase in the collector current of transistor Q 3 .
[0039] It is to be appreciated that since the illustrative amplifier 300 is symmetrical with respect to the two inputs VRN and VRP, the amplifier will respond to a complementary differential input signal in a manner consistent to that previously described. Consequently, with the voltage at input terminal VRN of amplifier 300 held constant, as the voltage at input terminal VRP is increased, transistor Q 3 will turn off and transistor Q 4 will turn on, thus providing a source output current through output IO of amplifier 300 . In either case, the slope of the linear increase in base voltage may be selectively controlled by adjusting the value of resistor R 1 until a desired response characteristic is obtained.
[0040] [0040]FIG. 4 illustrates an exemplary exponential transconductance amplifier 400 formed in accordance with another aspect of the present invention. Amplifier 400 is essentially the same as the amplifier 300 previously described in connection with FIG. 3, with the exception that the constant current source I 1 is replaced with temperature compensation circuitry for making the threshold region of amplifier 400 substantially constant over a given temperature range. As apparent from the figure, the temperature compensation circuitry preferably includes a bias current circuit 410 operatively coupled to a corresponding temperature-compensated bias voltage generator 408 . The bias current circuit 410 is connected between the positive voltage supply VCC and the common emitter node 308 . Bias voltage generator 408 includes a control input BIAS which may be used to selectively set the current in the amplifier 400 . The BIAS input may be connected, for example, to a constant current sink or resistor to ground to provide a predetermined reference current IREF (e.g., 200 microamperes (μa)).
[0041] The bias current circuit 410 of the illustrative amplifier 400 includes a pnp transistor Q 7 having a collector terminal (C) coupled to the common emitter node 308 , an emitter terminal (E) coupled to the positive voltage supply VCC through a series connected resistor R 2 , and a base terminal (B) coupled to the bias voltage generator 408 at node 402 . In conjunction with the corresponding bias voltage generator 408 , bias current circuit 410 produces a current I 1 in the differential input stage which is proportional to V BE /R 2 . It is to be appreciated that for optimum temperature tracking, resistor R 2 is preferably fabricated of the same material and similar geometry as resistor R 1 used to linearize the base-emitter voltage of transistors Q 3 and Q 4 , as previously described.
[0042] With continued reference to FIG. 4, the temperature-compensated bias voltage generator 408 preferably includes an npn transistor Q 8 and a pair of pnp transistors Q 5 and Q 6 , each of the transistors having a collector terminal (C), a base terminal (B) and an emitter terminal (E). The collector terminal of transistor Q 6 forms the BIAS input while the emitter terminal of transistor Q 6 is coupled to VCC via transistor Q 8 which is connected in a diode configuration. The base terminal of transistor Q 6 is coupled to the base terminal of transistor Q 7 at node 402 . Transistor Q 5 is connected in a base current compensation arrangement so that its emitter terminal is coupled to the base terminal of transistor Q 6 at node 402 , its collector terminal is coupled to ground and its base terminal is coupled to the collector terminal of transistor Q 6 at node 406 . With transistor Q 5 connected in this manner, a voltage at the base terminal of transistor Q 6 is prevented from rising more than the base-emitter voltage drop above the voltage presented to the BIAS input.
[0043] To insure proper matching, transistor Q 7 is preferably substantially matched to transistor Q 6 . With the base voltage at node 402 of the two transistors Q 6 , Q 7 being the same (i.e., V B =V BIAS +V EB,Q5 ), it can be easily shown that the base-emitter voltage of transistor Q 8 (V BE,Q8 ) will appear across resistor R 2 . Thus, the bias current I 1 will be substantially equal to V BE,Q8 /R 2 . The temperature coefficient of a typical base-emitter junction is approximately −2 mV/degree Celsius, while the temperature coefficient of a typical diffused resistor, for example, is on the order of a few thousand (e.g., 2000-4000) parts per million (ppm) per degree Celsius with a positive slope.
[0044] In a hard disk drive preamplifier application, the exponential transconductance amplifier of the present invention may be used in conjunction with a conventional linear transconductance amplifier, as previously stated, for providing a fast response time to widely varying load conditions. An example of such varying load conditions may include, for example, transitions from a read mode to a write mode, or vice versa, while reading data from or writing data to a storage medium, as previously described.
[0045] Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be made therein by one skilled in the art without departing from the scope or spirit of the invention.
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A non-linear transconductance amplifier includes a differential input stage and a non-linear transconductance stage operatively coupled to the differential input stage. The differential input stage includes first and second inputs forming a non-inverting input and an inverting input, respectively, of the amplifier for receiving an input differential signal. The non-linear transconductance stage generates an output of the amplifier having a linear transconductance that is substantially zero when the input differential signal is within a predetermined range and a non-linear large transconductance when the input differential signal is outside the predetermined range. The amplifier provides improved response time to widely varying load conditions while possessing a low loop bandwidth. A threshold region where the output of the amplifier is substantially zero can be operatively adjusted and tightly controlled. Furthermore, the amplifier accomplishes these advantages without employing timing circuitry and without the necessary overhead and/or noise often associated with such timing circuitry.
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This application is a Continuation of International Application No. PCT/FR2007/000119, filed Jan. 22, 2007, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The subject of the present invention is sulfonamide derivatives, their method of preparation and their therapeutic use.
BACKGROUND OF THE INVENTION
Orexins A and B (or hypocretins 1 and 2) are hypothalamic neuropeptides of 33 and 28 amino acids respectively, that were recently identified as endogenous ligands of two receptors having seven transmembrane domains, named orexin 1 and orexin 2 receptors (Sakurai T., Cell, Vol. 92, 573-585, 1998; De Lecea L., Proc. Natl. Acad. Sci., Vol. 95, 322-327, 1998).
The orexin 2 receptor has the property of recognizing the two forms of orexin A and B in an equivalent manner. On the other hand, the orexin 1 receptor, which exhibits 64% homology with the orexin 2 receptor, is more selective and binds orexin A ten times better than orexin B (Sakurai T., Cell, Vol. 92, 573-585, 1998).
Via these receptors, orexins control various central and peripheral functions, in particular food and drink intake, certain cardiovascular endocrine functions and the wake/sleep cycle (Sakurai T., Regulatory Peptides, Vol. 85, 25-30, 1999).
It has now been found that some sulfonamide derivatives have a high affinity for the orexin 2 receptors and are potent antagonists of these receptors.
SUMMARY OF THE INVENTION
Accordingly, the subject of the present invention is compounds corresponding to general formula (I)
in which
Ar 1 represents an aryl group, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a heterocyclyl group, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; T represents a group —(CH 2 ) n — with n=0, 1, 2; a group:
in which R is a hydroxyl group;
Ar 2 represents an aryl group, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 ) alkyl group and a (C 1 -C 4 )alkoxy group; a heterocyclyl group, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; Ar 3 represents an aryl group, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a hydroxyl group, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a heterocyclyl group, optionally substituted with one or more groups chosen independently of each other from the following groups: a hydroxyl group, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; R 1 represents a saturated heterocyclyl group of formula (A) which follows:
in which:
R 2 and R 3 represent independently of each other a hydrogen atom, a C 1 -C 3 alkyl group; or alternatively R 2 and R 3 form together an oxo group; R 4 represents a hydrogen atom or a C 1 -C 3 alkyl group; n=0 or 1; m=0 or 1; p=1 or 2;
provided that m and n never represent the value 0 at the same time;
or alternatively R 1 represents a cycloalkyl group of formula (B) which follows:
in which:
R 5 , R 6 and R 7 represent independently of each other a hydrogen atom or a C 1 -C 3 alkyl group; R 8 and R 9 represent independently of each other a hydrogen atom or a C 1 -C 3 alkyl group;
or alternatively R 8 and R 9 form together an oxo group;
n′=0, 1 or 2; p′=1, 2, 3 or 4;
in the form of a base, an addition salt with an acid, a hydrate or a solvate, in the form of enantiomers, diastereoisomers, rotamers, atropisomers or mixtures thereof.
DETAILED DESCRIPTION OF THE INVENTION
Among the compounds which are the subject of the invention, there may be mentioned a first group of compounds of general formula (I), in which
Ar 1 represents an aryl group, in particular a phenyl, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a heterocyclyl group, in particular pyridinyl or pyrimidinyl, said heterocyclyl group being optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; T represents a group —(CH 2 ) n — with n=1; Ar 2 represents an aryl group, in particular a phenyl, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a heterocyclyl group, in particular pyridinyl, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; Ar 3 represents an aryl group, in particular a phenyl, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a hydroxyl group, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a heterocyclyl group, in particular pyridinyl, furanyl or pyrazolyl, optionally substituted with one or more groups chosen independently of each other from the following groups: a hydroxyl group, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; R 1 represents a saturated heterocyclyl group of formula (A) in which: R 2 , R 3 and R 4 each represent a hydrogen atom or a (C 1 -C 4 ) alkyl group;
p=2; m=n=1; or m=0; n=1; p=2; or m=0; n=p=1; or m=n=p=1;
or alternatively R 1 represents a cycloalkyl group of formula (B) in which: R 5 , R 6 and R 7 represent independently of each other a hydrogen atom or a C 1 -C 3 alkyl group; R 8 and R 9 represent independently of each other a hydrogen atom or a C 1 -C 3 alkyl group; n′=0 or 1; p′=1, 2 or 3; in the form of a base, an addition salt with an acid, a hydrate or a solvate, in the form of enantiomers, diastereoisomers, rotamers, atropisomers or mixtures thereof.
Among the compounds which are the subject of the invention, there may be mentioned a second group of compounds of general formula (I), in which
Ar 1 represents an aryl group, in particular a phenyl, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a heterocyclyl group, in particular pyridinyl or pyrimidinyl, said heterocyclyl group being optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; T represents a group —(CH 2 ) n — with n=1; Ar 2 represents an aryl group, in particular a phenyl, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a heterocyclyl group, in particular pyridinyl, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; Ar 3 represents an aryl group, in particular a phenyl, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a hydroxyl group, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a heterocyclyl group, in particular pyridinyl or furanyl, optionally substituted with one or more groups chosen independently of each other from the following groups: a hydroxyl group, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 ) alkoxy group; R 1 represents a saturated heterocyclyl group of formula (A) in which: R 2 , R 3 and R 4 each represent a hydrogen atom or a (C 1 -C 4 ) alkyl group;
p=2; m=n=1; or m=0; n=1; p=2; or m=0; n=p=1; or m=n=p=1;
or alternatively R 1 represents a cycloalkyl group of formula (B) in which: R 5 , R 6 and R 7 represent independently of each other a hydrogen atom or a C 1 -C 3 alkyl group; R 8 and R 9 represent independently of each other a hydrogen atom or a C 1 -C 3 alkyl group; n′=0 or 1; p′=1, 2 or 3;
in the form of a base, an addition salt with an acid, a hydrate or a solvate, in the form of enantiomers, diastereoisomers, rotamers, atropisomers or mixtures thereof.
Among the compounds which are the subject of the invention, there may be mentioned a third group of compounds of general formula (I), in which
Ar 1 represents a phenyl group, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 ) alkyl group and a (C 1 -C 4 )alkoxy group; a pyridinyl or pyrimidinyl group, said pyridinyl and pyrimidinyl groups being optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom and a (C 1 -C 4 ) alkyl group; T represents a group —(CH 2 ) n — with n=1 Ar 2 represents a phenyl group optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a pyridinyl group, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; Ar 3 represents a phenyl group optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a hydroxyl group, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a pyridinyl, furanyl or pyrazolyl group, said groups optionally substituted with one or more groups chosen independently of each other from the following groups: a hydroxyl group, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 ) alkoxy group; R 1 represents a saturated heterocyclyl group of formula (A) in which:
R 2 , R 3 and R 4 each represent a hydrogen atom and m=0; n=1; p=2;
or alternatively R 1 represents a cycloalkyl group of formula (B) in which:
R 5 , R 6 , R 7 , R 8 and R 9 each represent a hydrogen atom;
n′=0 or 1 and p′=1, 2 or 3;
in the form of a base, an addition salt with an acid, a hydrate or a solvate, in the form of enantiomers, diastereoisomers, rotamers, atropisomers and mixtures thereof.
Among the compounds which are the subject of the invention, there may be mentioned a fourth group of compounds of general formula (I), in which
Ar 1 represents a phenyl group, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a pyridinyl or pyrimidinyl group, said pyridinyl and pyrimidinyl groups being optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom and a (C 1 -C 4 ) alkyl group; T represents a group —(CH 2 ) n — with n=1 Ar 2 represents a phenyl group optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group;
a pyridinyl group, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group;
Ar 3 represents a phenyl group optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a hydroxyl group, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a pyridinyl or furanyl group, said groups optionally substituted with one or more groups chosen independently of each other from the following groups: a hydroxyl group, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 ) alkoxy group; R 1 represents a saturated heterocyclyl group of formula (A) in which:
R 2 , R 3 and R 4 each represent a hydrogen atom and m=0; n=1; p=2;
or alternatively R 1 represents a cycloalkyl group of formula (B) in which:
R 5 , R 6 , R 7 , R 8 and R 9 each represent a hydrogen atom;
n′=0 or 1 and p′=1, 2 or 3;
in the form of a base, an addition salt with an acid, a hydrate or a solvate, in the form of enantiomers, diastereoisomers, rotamers, atropisomers or mixtures thereof.
Among the compounds which are the subject of the invention, there may be mentioned a fifth group of compounds of general formula (I), in which
Ar 1 represents a phenyl group, optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; a pyridinyl group; T represents a group —(CH 2 ) n — with n=1 Ar 2 represents a phenyl group optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a (C 1 -C 4 ) alkyl group and a (C 1 -C 4 )alkoxy group; Ar 3 represents a phenyl group optionally substituted with one or more groups chosen independently of each other from the following groups: a halogen atom, a hydroxyl group, a (C 1 -C 4 )alkyl group and a (C 1 -C 4 )alkoxy group; R 1 represents a saturated heterocyclyl group of formula (A) in which:
R 2 , R 3 and R 4 each represent a hydrogen atom; m=0; n=1 and p=2,
or alternatively R 1 represents a cycloalkyl group of formula (B) in which:
R 5 , R 6 , R 7 , R 8 and R 9 represent independently of each other a hydrogen atom; n′=0 and p′=3; in the form of a base, an addition salt with an acid, a hydrate or a solvate, in the form of enantiomers, diastereoisomers, rotamers, atropisomers or mixtures thereof.
Among the compounds which are the subject of the invention, there may be mentioned a sixth group of compounds of general formula (I), chosen from:
N-[4-chloro-2-(2,6-difluorobenzyl)phenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 1); N-[4-chloro-2-(2,6-difluorobenzyl)phenyl]-3,4-dimethoxy-N-piperidin-4-ylbenzenesulfonamide hydrochloride (compound No. 2); N-[4-chloro-2-(2,5-difluorobenzyl)phenyl]-3,4-dimethoxy-N-pyrrolidin-3-ylbenzenesulfonamide hydrochloride (compound No. 3); N-[4-chloro-2-(2,6-difluorobenzyl)phenyl]-3,4-dimethoxy-N-[(3R)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 4); N-azetidin-3yl-N-[4-chloro-2-(2,6-difluorobenzyl)-phenyl]-3,4-dimethoxybenzenesulfonamide hydrochloride (compound No. 5); Atropisomer A 1 of N-[2-(2,6-difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 6); Atropisomer B 1 of N-[2-(2,6-difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 7); N-[(1R,2S)-2-aminocyclopentyl]-N-[2-(2,6-difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxybenzene-sulfonamide hydrochloride (compound No. 8); N-[4-chloro-2-(pyridin-2-ylmethyl)phenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 9); N-[4-chloro-2-(pyridin-2-ylmethyl)phenyl]-3,4-dimethoxy-N-[(3R)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 10); Atropisomer A 2 of N-[2-(2-chlorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 11); Atropisomer B 2 of N-[2-(2-chlorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 12); N-[[2-(2,6-difluorobenzyl)-5-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 13); Atropisomer A 3 of N-[(1S,2S)-2-aminocyclopentyl]-N-[2-(2,6-difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-benzenesulfonamide hydrochloride (compound No. 14); Atropisomer B 3 of N-[(1S,2S)-2-aminocyclopentyl]-N-[2-(2,6-difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-benzenesulfonamide hydrochloride (compound No. 15); N-[4-chloro-2-(2,6-difluorobenzyl)phenyl]-3-fluoro-4-methyl-N-[(3R)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 16); N-[4-chloro-2-(2,6-difluorobenzyl)phenyl]-3-fluoro-4-methyl-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 17); Atropisomer A 4 of N-[2-(2,6-difluorobenzyl)-4-chloro-6-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 18); Atropisomer B 4 of N-[2-(2,6-difluorobenzyl)-4-chloro-6-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 19); Atropisomer A 5 of N-[2-(2,6-difluorobenzyl)-6-methoxyphenyl]-3-fluoro-4-methyl-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 20); Atropisomer B 5 of N-[2-(2,6-difluorobenzyl)-6-methoxyphenyl]-3-fluoro-4-methyl-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 21); N-[2-(2,6-difluorobenzyl)-4-methylphenyl]-3,4-difluoro-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide trifluoroacetate (compound No. 22); N-[4-(2,6-difluorobenzyl)phenyl]-1,3,5-trimethyl-N-[(3S)-pyrrolidin-3-yl]-1H-pyrazole-4-sulfonamide hydrochloride (compound 23).
Among the compounds which are the subject of the invention, there may be mentioned a seventh group of compounds of the general formula (I), chosen from:
N-[4-chloro-2-(2,6-difluorobenzyl)phenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 1); Atropisomer A 1 of N-[2-(2,6-difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 6); N-[(1R,2S)-2-aminocyclopentyl]-N-[2-(2,6-difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-benzenesulfonamide hydrochloride (compound No. 8); Atropisomer A 2 of N-[2-(2-chlorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 11); Atropisomer A 3 of N-[(1S,2S)-2-aminocyclopentyl]-N-[2-(2,6-difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-benzenesulfonamide hydrochloride (compound No. 14); Atropisomer A 4 of N-[2-(2,6-difluorobenzyl)-4-chloro-6-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride (compound No. 18).
When Ar 2 is an optionally substituted phenyl group, the T-Ar 2 bonds, on the one hand, and the Ar 2 -N bonds, on the other hand, are in the ortho position. In other words, the nitrogen atom and the substituent T are on two adjacent carbon atoms.
In the context of the invention,
a (C 1 -C 4 )alkyl group is understood to mean: a linear or branched saturated aliphatic group comprising from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl or tert-butyl; an optionally substituted (C 1 -C 4 )alkyl group is understood to mean: an alkyl group as defined above in which one or more hydrogen atoms have been substituted with a substituent; a (C 1 -C 4 )alkoxy group is understood to mean: a (C 1 -C 4 )alkyl-O— radical where the (C 1 -C 4 )alkyl group is as defined above, for example methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy or tert-butoxy; a halogen atom is understood to mean: a fluorine atom, a chlorine atom, a bromine atom or an iodine atom; a cycloalkyl group is understood to mean: a saturated cyclic alkyl group comprising from 3 to 8 carbon atoms, for example cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl. The cycloalkyl group may be optionally substituted with a (C 1 -C 4 )alkyl group, for example methylcyclopropyl, dimethylcyclopropyl, methylcyclobutyl, methylcyclopentyl, methylcyclohexyl, dimethyl-cyclohexyl, cycloheptyl or cyclooctyl; an aryl group is understood to mean: a monocyclic or bicyclic aromatic group comprising between 6 and 10 carbon atoms, for example phenyl or naphthyl. The aryl group may be optionally substituted with 1, 2, 3 or 4 substituents; a heterocyclyl group is understood to mean: a saturated, unsaturated or aromatic monocyclic group comprising between 4 and 7 atoms and comprising from 1 to 2 heteroatoms chosen from nitrogen, oxygen or sulfur. By way of example, there may be mentioned azetidine, piperidinyl, pyrrolidinyl, 1,3-dioxolanyl, imidazolyl, pyrazolyl, pyridinyl, thiazolyl, thienyl, pyrimidinyl or furanyl; an aralkyl group is understood to mean: an alkyl chain substituted with an aryl group, such as for example a benzyl group; an oxo group is understood to mean: a group of formula:
for example a group R 1 which represents a saturated heterocyclyl group of formula (A) in which:
R 2 , R 3 and R 4 each represent a hydrogen atom; p=2 and m=n=1, is a piperidinyl group; or R 2 , R 3 and R 4 each represent a hydrogen atom; m=0; n=1 and p=2, is a pyrrolidinyl group; R 2 , R 3 and R 4 each represent a hydrogen atom; m=0 and n=p=1, is an azetidine group;
for example, a group R 1 which represents a cycloalkyl group of formula (B) in which:
R 5 , R 6 , R 7 , R 8 and R 9 each represent a hydrogen atom, p′=3 and n′=0, is a cyclopentyl group.
The compounds of general formula (I) may contain one or more asymmetric carbons. They can therefore exist in the form of enantiomers or diastereoisomers. These enantiomers and diastereoisomers, and mixtures thereof, including the racemic mixtures, form part of the invention.
By virtue of their structure, the compounds of general formula (I) may also be in the form of rotamers. In the context of the invention, the expression rotamers is understood to mean compounds which have identical structural formulae but different rigid spatial conformations. These differences in the rigid spatial conformations of these compounds can therefore confer different physicochemical properties on them and, even in some cases, different biological activities.
The compounds of general formula (I) may also exist in the form of atropisomers. The atropisomers are compounds with identical structural formulae, but which have a particular spatial configuration resulting from a restricted rotation around a single bond, due to a major steric hindrance on either side of this single bond. Atropisomerism is independent of the presence of stereogenic elements, such as an asymmetric carbon.
The compounds of formula (I) may exist in the form of bases or of addition salts with acids. Such addition salts form part of the invention. These salts are advantageously prepared with pharmaceutically acceptable acids, but the salts of other acids useful, for example, for the purification or separation of the compounds of general formula (I) also form part of the invention.
The compounds of general formula (I) may additionally be in the form of hydrates or solvates, namely in the form of associations or combinations with one or more molecules of water or with a solvent. Such hydrates and solvates also form part of the invention.
The subject of the present invention is also the method for preparing the compounds of general formula (I).
Accordingly, the compounds of general formula (I) may be prepared by the method illustrated in scheme 1. According to this scheme, the compounds of formula (I) may be obtained by a Mitsunobu reaction between the alcohols of formula (X) and the compounds of general formula (II).
In the compounds of formula (II), and (X), Ar 1 , Ar 2 , Ar 3 , T and R 1 are as defined in formula (I).
In the Mitsunobu reaction, diisopropyl azodicarboxylate (DIAD) may be replaced by its analogs such as diethyl azodicarboxylate and di-tert-butyl azodicarboxylate, and triphenylphosphine may be grafted onto a resin (R. G. Gentiles et al., J. Comb. Chem. 2002, 4, 442-456).
The compounds of formula (I) for which R 4 is a hydrogen and R 6 and R 7 are hydrogens are obtained from compounds for which R 4 and R 6 are protecting groups, for example a tert-butoxycarbonyl (BOC).
The compounds of formula (I), for which T=—(CH 2 ) n — with n=1, may in some cases be obtained from the compounds having the structure (I), for which T=—CH(R)— in which R represents a hydroxyl group, by the action of a hydride, for example triethylsilane, in the presence of boron trifluoride etherate.
The compounds of formula (I), for which
in which R represents a hydroxyl group, may, in some cases, be obtained from the corresponding ketone:
by the action of a hydride, for example sodium borohydride.
The compounds of formula (II) are obtained beforehand according to scheme 2, by sulfonylation of the compound of formula (III) with sulfonyl chlorides of formula (V) in the presence of a base chosen from tertiary amines such as pyridine according to the method described by Stauffer et al., Bioorg. Med. Chem. 2000, EN 8, 6, 1293-1316. As tertiary amines, triethylamine or diisopropylethylamine may also be used.
In some cases, it is possible to even envisage using a mixture of tertiary amines. The compounds of formula (V) are commercially available or may be obtained by adaptation of the methods described, for example, by A. J. Prinsen et al., Recl. Trav. Chim. The Netherlands 1965, EN 84, 24.
In the compounds of formula (III) and (V), Ar 1 , Ar 2 , Ar 3 and T are as defined in formula (I).
The compounds of formula (IIIa), (IIIb) and (IIIf) are prepared according to schemes 3 to 5. The 2-nitrobenzaldehyde derivatives of formula (VI) react with organometallic compounds of formula (VII) in which M represents a group MgBr, MgI, ZnI or Li to give the compounds of formula (VIII). The organometallic compounds of formula (VII) are commercially available, or are formed according to conventional methods described in the literature. The nitro functional group of the compounds of formula (VIII) are reduced by hydrogenation, for example under the action of metal tin and of concentrated hydrochloric acid in ethanol, to give the compounds of formula (IIIb). The derivatives of formula (IIIb) are reduced by the action of hydrides, for example with a mixture of triethylsilane and trifluoroacetic acid in dichloromethane to give the derivatives of formula (IIIa).
The nitrobenzaldehydes of formula (VI) are commercially available or may be prepared, for example, according to an adaptation of the method described by J. Kenneth Horner et al., J. Med. Chem., 1968, 11; 5; 946.
Other possibilities for synthesizing the compounds of general formulae (IIIb) and (IIIf) are presented in scheme 4.
The anilines of formula (IX) are condensed with benzonitriles of formula (XII), in the presence of a Lewis acid such as for example boron trichloride with aluminum trichloride or with gallium trichloride to give the compounds of formula (IIIf), according to the method described by T. Sugasawa et al. J.A.C.S. 1978; 100; 4842. The compounds of formula (IIIf) may be obtained by condensation of aminobenzonitriles (XI) with the organometallic derivatives (VII), according to the method described by R. Fryer et al., J. Heterocycl. Chem. 1991, EN 28; 7, 1661. The compounds of formula (IIIf) may also be obtained from the intermediate (XIV) according to an adaptation of the method described by D. Lednicer, J. Heterocyclic. Chem. 1971; 903.
The carbonyl functional group of the compounds (IIIf) is reduced by the action of a hydride, for example sodium borohydride in ethanol, to give the compounds of formula (IIIb).
Another method for preparing the compounds of formula (IIIb) consists in condensing anilines of formula (IX) with benzaldehyde derivatives of formula (XIII) in the presence of phenyldichloroborane and triethylamine according to the method described by T. Toyoda et al., Tet. Lett, 1980, 21, 173.
It should be noted that the compounds of formula (IIIf) under the action of triethylsilane and trifluoroacetic acid for example can lead to the compounds of formula (IIIa).
Another possibility for synthesizing the compounds of general formulae (IIIa), in which Ar 1 represents a heteroaryl, is presented in scheme 5.
The nitrophenyls of formula (XVII) are condensed with aromatic chloromethylheterocyclyl in the presence of a base, for example potassium tert-butoxide, to give the derivatives (XIX) according to the method described by Florio. S et al., Eur. J. Org. Chem. 2004, 2118, which are reduced for example by the action of metal tin in the presence of 12M hydrochloric acid, to give the derivatives of formula (IIIa).
The compounds of formula (IIIg) are prepared according to scheme 6. The nitrobenzaldehydes (VI), by condensation with the derivatives (XV) according to a Wittig reaction, lead to the compounds (XVI). These derivatives are reduced for example by catalytic hydrogenation with palladium to give the compounds of formula (IIIg).
In all the schemes and for all the compounds of formulae (II) to (XIX), the meanings of Ar 1 , T, Ar 2 , Ar 3 , R 1 are as defined for the compounds of general formula (I).
In schemes 1 to 6, the starting compounds and the reagents, when their mode of preparation is not described, are commercially available or are described in the literature, or alternatively may be prepared by methods which are described therein or which are known to persons skilled in the art.
When a compound contains a reactive functional group, for example a hydroxyl group, it may require prior protection before reaction. Persons skilled in the art will be able to determine the need for prior protection.
The compounds of formula (II) to (XIX) are useful as synthesis intermediates for the preparation of the compounds of general formula (I) and form an integral part of the present invention.
EXAMPLES
The following examples describe the preparation of the compounds in accordance with the invention. These examples are not limiting and merely illustrate the invention.
The exemplified compound numbers refer to those given in the table. Elemental microanalyses, mass spectra and NMR spectra confirm the structures of the compounds obtained.
The conditions for analysis by mass spectrometry coupled liquid chromatography LC/MS are the following:
for the liquid chromatography part: symmetry column C18 (2.1×50 mm) 3-5 μm. Eluent A=H 2 O+0.005% of TFA, pH=3.14; eluent B=CH 3 CN+0.005% of TFA, with a gradient from 100% of A to 90% of B over 10 minutes, and then 5 minutes at 90% of B for the mass spectrometry part: positive electrospray ionization mode.
When the 1 H NMR spectrum identifies rotamers, only the interpretation corresponding to the predominant rotamer is described.
In the following tables:
m.p.(° C.) represents the melting point of the compound in degrees Celsius MH + represents the mass peak of the ionized product the retention time is expressed in minutes n.d. means “not determined” Me=methyl
Example 1
N-[2-(2,6-Difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzene-sulfonamide hydrochloride (compound 6)
Example 1.1
(2,6-Difluorophenyl)(3-methoxy-2-nitrophenyl)methanol
77.5 ml of a 1.6M solution of n-butyllithium (1.5 eq.) in hexane are added dropwise in order to maintain a temperature of less than or equal to −70° C. to a solution of 12.3 ml of 1,3-difluorobenzene (1.5 eq.) in 150 ml of tetrahydrofuran over 1 hour. After an additional 1 hour at −70° C., a solution of 15 g of 2-nitro-3-methoxybenzaldehyde in tetrahydrofuran is added over 1 hour still at −70° C. The reaction medium is stirred for 4 hours at −70° C. and then brought to a temperature of −5° C. over 1 hour. The reaction medium is then diluted by adding diethyl ether and then slowly hydrolyzed with a saturated aqueous solution of ammonium chloride. After decantation, the organic phase is washed with water and then dried over anhydrous sodium sulfate. The residue is chromatographed on silica gel, eluting with a dichloromethane/cyclohexane mixture (1/1) (v/v) in order to obtain 13.4 g of the expected product.
1 H NMR 6 in ppm (DMSO d 6): 3.85 (s, 3H); 6.16 (t, 1H); 6.53 (d, 1H); 7.00-7.61 (unresolved complex, 6H).
Example 1.2
(2-Amino-3-methoxyphenyl)(2,6-difluorophenyl)methanol
13.3 g of (2,6-difluorophenyl)(3-methoxy-2-nitro-phenyl)methanol are dissolved in 75 ml of ethanol. At 0° C., 37 ml of concentrated hydrochloric acid (10 eq.) are slowly added to 10.5 g of tin (2.2 eq.) (exothermic reaction). After 18 hours, the ethanol is evaporated, the residue is taken up in ethyl acetate before being alkalinized with a 3N aqueous sodium hydroxide solution until the pH is close to 14. After decantation, the organic phase is dried over anhydrous sodium sulfate and concentrated in order to obtain 8.7 of the expected product.
1 H NMR δ in ppm (DMSO d 6): 3.79 (s, 3H); 4.48 (s, 2H); 5.98 (t, 1H) 6.07 (d, 1H); 6.52-7.43 (unresolved complex, 6H).
Example 1.3
2-(2,6-Difluorobenzyl)-6-methoxyaniline
The reaction mixture composed of 5.8 g of (2-amino-3-methoxyphenyl)(2,6-difluorophenyl)methanol, 11 ml of triethylsilane (3 eq.), 10 ml of trifluoroacetic acid (3.9 eq.) in 90 ml of dichloromethane is heated for 6 hours at 40° C. After one night at room temperature, the reaction medium is slowly hydrolyzed in the cold state with 6N sodium hydroxide, the organic phase is dried over anhydrous sodium sulfate and concentrated. The residue is purified by filtration on silica H, eluting with dichloromethane, in order to obtain 3.8 g of the expected product.
1 H NMR δ in ppm (DMSO d 6): 3.77 (s, 5H); 4.65 (s, 2H); 6.15 (d, 1H) 6.45 (t, 1H); 6.70 (d, 1H); 7.12-7.46 (unresolved complex, 3H).
Example 1.4
N-[2-(2,6-Difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxybenzene-sulfonamide
3.8 g of 2-(2,6-difluorobenzyl)-6-methoxyaniline are dissolved in 36 ml of tetrahydrofuran and 1.2 ml of pyridine, and then 4.06 g of 3,4-dimethoxybenzene-sulfonyl chloride are then added. After 18 hours at room temperature, the reaction medium is taken up in ethyl acetate and then hydrolyzed, the organic phase is dried over anhydrous sodium sulfate and concentrated. The residue is solidified in a toluene/ethyl acetate mixture (9/1) (v/v) in order to obtain 5 g of expected product.
1 H NMR δ in ppm (DMSO d 6): 3.17 (s, 3H); 3.75 (s, 3H); 3.83 (s, 3H) 4.22 (s, 2H); 6.37 (d, 1H); 6.75 (d, 1H); 7.02-7.43 (unresolved complex, 7H); 9.16 (s, 1H).
Example 1.5
tert-Butyl (3S)-3-{[6-methoxy-2-(2,6-difluorophenyl][(3,4-dimethoxy-phenyl)sulfonyl]amino}pyrrolidine-1-carboxylate
1.55 g of di-tert-butyl azodicarboxylate are added at room temperature to 2.8 g of triphenylphosphine in solution in 25 ml of tetrahydrofuran. After 30 minutes, 0.95 g of tert-butyl (3R)-3-hydroxypyrrolidine-1-carboxylate is introduced. After 30 minutes, 1.46 g of N-[2-(2,6-difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxybenzenesulfonamide are added and the mixture is left for 48 hours at room temperature. The reaction medium is concentrated and chromatographed on silica gel in order to obtain 0.44 g of the first atropisomer and 0.42 g of the second atropisomer.
Example 1.6
N-[2-(2,6-Difluorobenzyl)-6-methoxyphenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidin-3-yl]benzenesulfonamide hydrochloride
7 ml of a 2M hydrogen chloride solution in diethyl ether are added to 0.44 g of the first atropisomer tert-butyl (3S)-3-{[6-methoxy-2-(2,6-difluorophenyl]-[(3,4-dimethoxyphenyl)sulfonyl]amino}pyrrolidine-1-carboxylate in ethyl acetate. After 18 hours at room temperature, the medium is filtered and the precipitate is taken up in a dichloromethane/ethyl acetate mixture at 70° C. The insoluble material is filtered in order to obtain 0.084 g of the expected product.
1 H NMR δ in ppm (DMSO d 6): 1.76 (m, 1H); 2.43 (m, 1H) 2.80 (t, 1H); 3.17 (m, 3H); 3.38 (s, 3H); 3.80 (s, 3H); 3.84 (s, 3H); 4.05 (q, 2H); 4.72 (q, 1H); 6.36 (d, 1H); 6.95 (d, 1H); 7.14-7.53 (unresolved complex, 7H); 9.19 (s, 2H).
m.p.=254° C.
The terms “atropisomer A n ” or “atropisomer B n ” are used in order to be able to clearly name two atropisomers of the same pair.
In the text that follows, the melting points were determined with the apparatus:
(M)=Metler Toledo, (K)=Kofler stage
In table I which follows, the compounds are in the monohydrochloride form
TABLE I
(Ia)
Compound
Nature and position of the substituents
m.p.
MH + /retention
No.
on Ar 1
on Ar 2
R 1
on Ar 3
(° C.)
time
1
2,6-diF
4-Cl
3,4-diOMe
199 (M)
523/7.00
2
2,6-diF
4-Cl
3,4-diOMe
185.5 (M)
537/6.41
3
2,5-diF
4-Cl
3,4-diOMe
122 (M)
523/7.02
4
2,6-diF
4-Cl
3,4-diOMe
197.9 (M)
523/6.93
5
2,6-dIF
4-Cl
3,4-diOMe
171.8 (M)
509/6.91
8
2,6-diF
6-OMe
3,4-diOMe
138.2 (M)
488.1/5.64
Compounds 6 and 7 form a pair of atropisomers.
For Compound 6 (Atropisomer A 1 ):
m.p.=129° C. (M) (α D )=+54.3 at c=0.35 g/dl in methanol MH + /retention time: 519.2/6.56
For Compound 7 (Atropisomer B 1 ):
m.p.=254° C. (M) α D =−25.95 at c=0.42 g/dl in methanol MH + /retention time: 519.2/6.56
Other compounds of formula (Ia) are given by way of example in table I′ below. These compounds are in the monohydrochloride form.
TABLE I′
Compound
Nature and position of the substituents
m.p.
MH + /retention
No.
on Ar 1
on Ar 2
R 1
on Ar 3
(° C.)
time
11 (atropisomer A 2 )
2-Cl
6-OMe
3,4-diOMe
231 (M)
517/6.78
12 (atropisomer B 2 )
2-Cl
6-OMe
3,4-diOMe
160.9 (M)
517/6.67
13
2,6-diF
5-OMe
3,4-diOMe
136.4 (M)
519/670
14 (atropisomer A 3 )
2,6-diF
6-OMe
3,4-diOMe
156 (K)
533/6.70
15 (atropisomer A 3 )
2,6-diF
6-OMe
3,4-diOMe
156 (K)
533/6.87
16 (R)
2,6-diF
4-Cl
3-F 4-Me
148 (K)
495/7.48
17 (S)
2,6-diF
4-Cl
3-F 4-Me
145 (K)
495/7.45
18 (atropisomer A 4 )
2,6-diF
4-Cl 6-OMe
3,4-diOMe
262.8 (M)
553/6.96
19 (atropisomer B 4 )
2,6-diF
4-Cl 6-OMe
3,4-diOMe
202 (M)
553/7.00
20 (atropisomer A 5 )
2,6-diF
6-OMe
3-F 4-Me
110 (K)
491/6.65
21 (atropisomer B 5 )
2,6-dIF
6-OMe
3-F 4-Me
122 (K)
491/6.71
The pairs of compounds which follow form pairs of atropisomers:
compounds 11 and 12, compounds 14 and 15, compounds 18 and 19, compounds 20 and 21.
Compound 22 in table I″ which follows is in the trifluoroacetate form:
TABLE I″
Nature and position of the substituents
m.p.
MH + /retention
Compound No.
on Ar 1
on Ar 2
R 1
on Ar 3
(° C.)
time
22
2.6-diF
4-Me
3.4-dIF
97.9 (M)
479/7.29
Example 2
N-[4-Chloro-2-(pyridin-2-ylmethyl)phenyl]-3,4-dimethoxy-N-[(3S)-pyrrolidinyl-3-yl]benzene-sulfonamide hydrochloride (compound No. 10)
Example 2.1
2-(5-Chloro-2-nitrobenzyl)pyridine
8.66 g of 4-chloronitrobenzene and 8.2 g of 2-chloromethylpyridine in solution in 100 ml of dimethyl sulfoxide are slowly added to 22.44 g of potassium tert-butoxide in 500 ml of dimethyl sulfoxide. After 18 hours at room temperature, the mixture is hydrolyzed with a saturated ammonium chloride solution and extracted three times with dichloromethane. The organic phase is dried over anhydrous sodium sulfate and concentrated. The residue is filtered on silica H (eluent dichloromethane) in order to obtain 10.695 g of the expected product.
1 H NMR δ in ppm (DMSO d 6): 4.49 (s, 2H); 7.20-7.31 (unresolved complex, 2H); 7.60-7.78 (unresolved complex, 3H); 8.03 (d, 1H); 8.41 (d, 1H)
m.p.=69° C.
Example 2.2
4-Chloro-2-pyridin-2-ylmethyl)aniline
4.7 g of metal tin and then 16.8 ml of 12M hydrochloric acid are successively added at room temperature to 5 g of 2-(5-chloro-2-nitrobenzyl)pyridine in solution in 34 ml of ethanol. After 2 hours at room temperature, the medium is neutralized at 0° C. by the addition of 6M sodium hydroxide. The reaction medium is extracted with ethyl acetate, the organic phase is dried over anhydrous sodium sulfate and concentrated in order to obtain 3.86 g of the expected product.
1 H NMR δ in ppm (DMSO d 6): 3.93 (s, 2H); 5.33 (s, 2H); 6.66 (d, 1H); 6.93-7.06 (unresolved complex, 2H); 7.21-7.38 (unresolved complex, 2H); 7.76 (m, 1H); 8.47 (d, 1H)
Example 2.3
N-[4-Chloro-2-(pyridin-2-ylmethyl)-phenyl]-3,4-dimethoxybenzenesulfonamide
0.7 ml of pyridine and then 2.27 g of 3,4-dimethoxybenzenesulfonyl chloride are successively added at room temperature to 1.86 g of 4-chloro-2-(pyridin-2-ylmethyl)aniline in solution in 20 ml of tetrahydrofuran. After 72 hours at room temperature, the reaction medium is taken up in water and extracted with ethyl acetate, the organic phase is dried over anhydrous sodium sulfate and concentrated in order to obtain 2.12 g of the expected product.
1 H NMR δ in ppm (DMSO d 6): 3.71 (s, 3H); 3.83 (s, 3H); 3.94 (s, 2H); 7.07-7.32 (unresolved complex, 8H); 7.74 (m, 1H); 8.54 (d, 1H)
Example 2.4
tert-Butyl (3R)-3-{[4-chloro-2-(pyridin-ylmethyl)phenyl][(3,4-dimethoxyphenyl)-sulfonyl]amino}pyrrolidine-1-carboxylate
0.91 ml of diisopropylazodicarboxylate is added at room temperature to 1.21 g of triphenylphosphine in solution in 25 ml of tetrahydrofuran. After 30 minutes, 0.86 g of tert-butyl (3S)-3-hydroxypyrrolidine-1-carboxylate is introduced. After 30 minutes, 1.29 g of N-[4-chloro-2-(pyridin-2-ylmethyl)phenyl]-3,4-dimethoxybenzene-sulfonamide are added and the mixture is left for 18 hours at room temperature. The reaction medium is concentrated and chromatographed on silica gel in order to obtain 2.94 g of the expected product.
1 H NMR δ in ppm (DMSO d 6): 1.36 (s, 9H); 1.6 (m, 1H); 2.15 (m, 1H); 2.8-3.1 (unresolved complex, 3H); 3.6 (m, 1H); 3.78 (s, 3H); 3.88 (s, 3H); 4.2-4.6 (unresolved complex, 3H); 7.09-7.75 (unresolved complex, 10H).
Example 2.5
N-[4-Chloro-2-(pyridin-2-ylmethyl)-phenyl]-3,4-dimethoxy-N-[(3R)-pyrrolidinyl-3-yl]-benzenesulfonamide hydrochloride
2.8 ml of a 2M hydrogen chloride solution in diethyl ether are added to 2.94 g of tert-butyl (3R)-3-{[4-chloro-2-(pyridin-ylmethyl)phenyl][(3,4-dimethoxy-phenyl)sulfonyl]amino}pyrrolidine-1-carboxylate in 3 ml of ethyl acetate. After 18 hours at room temperature, the reaction medium is concentrated and the residue is solidified with diethyl ether in order to obtain, after drying, 0.921 g of the expected product.
1 H NMR δ in ppm (DMSO d 6): 1.38 (m, 1H); 1.76 (m, 1H); 3.0-3.3 (unresolved complex, 4H); 3.79 (s, 3H); 3.88 (s, 3H); 4.55-4.88 (unresolved complex, 3H); 6.60-8.50 (unresolved complex, 10H); 14.1 (s, 1H).
m.p.=138.2° C.
In table II which follows, the compounds are in the monohydrochloride form.
TABLE II
(Ib)
Com-
MH + /
pound
Nature and position of the substituents
m.p.
retention
No.
on Ar 1
on Ar 2
R 1
on Ar 3
(° C.)
time
9 (S)
H
4-Cl
3,4-diOMe
138.2 (M)
488/5.71
10 (R)
H
4-Cl
3,4-diOMe
203.4 (M)
488/5.73
In table III which follows, the compound is in the monohydrochloride form.
TABLE III
(Ib)
Compound
Nature and position of the substituents
m.p.
MH + /retention
No.
on Ar 1
on Ar 2
R 1
on Ar 3
(° C.)
time
23
2,6-diF
4-Cl
N-1-Me 3-Me 5-Me
144.6 (M)
495/6.60
Pharmacological Testing
The compounds of the invention were the subject of pharmacological studies which showed their importance as active substances in therapy.
They were in particular tested for their effects. More particularly, the affinity of the compounds of the invention for the orexin 2 receptors was determined in an in vitro binding test according to the technique described below. This method consists in studying the displacement of radioiodinated orexin A attached to the human orexin 2 receptors expressed in CHO cells. The test is performed on membranes in a 50 mM Hepes incubation buffer containing 1 mM MgCl 2 , 25 mM CaCl 2 , 0.025% NaN 3 , 1% bovine serum albumin (BSA) and 100 pM of ligand for 30 minutes at 25° C. The reaction is stopped by filtration and washing on a Whatman GF/C filter. The nonspecific binding is measured in the presence of 10 −6 M human orexin B. The IC 50 values (concentration inhibiting 50% of the binding of radioiodinated orexin A to its receptors) are low, less than 300 nM, in particular less than 100 nM and more particularly less than 30 nM.
The affinity of the compounds according to the invention for the orexin 1 receptors was also studied in an in vitro binding test according to the same technique using radioiodinated orexin A as ligand in a membrane preparation of CHO cells expressing the human orexin 1 receptors. The compounds according to the invention have little or no affinity for the orexin 1 receptors.
The agonist or antagonist character of the compounds is determined in vitro for the test for measuring intracellular calcium (FLIPR) on a cellular preparation expressing the orexin 2 receptors according to the general technique described in Sullivan et al., Methods Mol. Biol., 1999, Vol. 114, 125-133, using 1 μM of Fluo-4 AM as fluorescent calcium indicator. For the antagonist test, the compounds are preincubated for 30 minutes before adding 0.25 nM of orexin B. The IC 50 values for the orexin 2 receptors measured in these studies are low and more particularly less than 100 nM.
The IC 50 values were measured for the compounds according to the invention (compound Nos. 1, 6, 8, 11, 14 and 18). The data which follow serve to illustrate the invention and are not limiting.
TABLE 1
Compound No.
IC 50 OX 2 (nM)
6
9.1
8
11
11
7.2
14
10
18
12
The following table illustrates the affinity of a few compounds according to the invention for the orexin 1 and 2 receptors, in an in vitro binding test according to the technique described above.
TABLE 2
Compound No.
IC 50 OX 2 (nM)
IC 50 OX 1 (nM)
1
16.4
1380
7
9
103
The biological results show that the compounds according to the invention are indeed specific antagonists for the orexin 2 receptors.
Their antagonist character is determined in vitro in a test for measuring intracellular calcium (FLIPR) according to the general technique mentioned above.
Accordingly, the compounds of the present invention, as antagonists for the orexin 2 receptors, may be used in the prophylaxis and treatment of any diseases involved in a dysfunction linked to these receptors.
The compounds of the invention may be used for the preparation of a medicament intended for the prophylaxis or for the treatment of any diseases involving a dysfunction linked to the orexin 2 receptor, and more particularly in the prophylaxis or the treatment of pathologies in which an orexin 2 receptor antagonist provides a therapeutic benefit. Such pathologies are for example obesity, appetite or taste disruptions including cachexia, anorexia, bulimia (Smart et al., Eur. J. Pharmacol., 2002, 440, 2-3, 199-212), diabetes (Ouedraogo et al., Diabetes, 2002, 52, 111-117), metabolic syndromes (Sakurai, Curr. Opin. Nutr. Metab. Care, 2003, 6, 353-360), vomiting and nausea (U.S. Pat. No. 6,506,774), depression and anxiety (Salomon et al., Biol. Psychiatry, 2003, 54, 96-104; Jaszberenyi et al., J. Neuroendocrinol., 2000, 12, 1174-1178), epilepsy (Morales et al. Brain Res., 2006, 1109, 164-175), addictions (Georgescu et al., J. Neurosci., 2003, 23, 8, 3106-3111; Kane et al., Endocrinology, 2000, 141, 10, 3623-3629), mood and behavioral disorders, schizophrenia (Nishino et al., Psychiatry Res., 2002, 110, 1-7), sleep disorders (Sakurai, Neuroreport, 2002, 13, 8, 987-995), restless leg disease (Allen et al., Neurology, 2002, 59, 4, 639-641), learning and memory disorders (van den Pol et al., 2002, J. Physiol., 541(1), 169-185; Jaeger et al., Peptides, 2003, 23, 1683-1688; Telegdy and Adamik, Regul. Pept., 2002, 104, 105-110), sexual and psychosexual dysfunctions (Gulia et al., Neuroscience, 2003, 116, 921-923), pain, visceral or neuropathic pain, hyperalgesia, allodynia (U.S. Pat. No. 6,506,774; Suyama et al., In vivo, 2004, 18, 2, 119-123), digestive disorders (Takakashi et al., Biochem. biophy. Res. Comm., 1999, 254, 623-627; Matsuo et al., Eur. J. Pharmacol., 2002, 105-109), irritable bowel syndrome (U.S. Pat. No. 6,506,774), neuronal degeneration (van den Pol, Neuron, 2000, 27, 415-418), ischemic or hemorrhagic strokes (Irving et al., Neurosci. Lett., 2002, 324, 53-56), Cushing's disease, Guillain-Barré syndrome (Kanbayashi et al., Psychiatry Clin. Neurosci., 2002, 56, 3, 273-274), myotonic dystrophy (Martinez-Rodriguez et al., Sleep, 2003, 26, 3, 287-290), urinary incontinence (Blackstone et al., AGS Annual Meeting, poster P491,2002), hyperthyroidism (Malendowicz et al., Biomed. Res., 2001, 22, 5, 229-233), pituitary function disorders (Voisin et al., Cell. Mol. Life. Sci., 2003, 60, 72-78), hypertension or hypotension (Samson et al. Brain Res., 1999, 831, 1-2, 248-253).
The use of the compounds according to the invention for the preparation of a medicament intended for the prevention or treatment of the above-mentioned pathologies forms an integral part of the invention.
The subject of the invention is also medicaments which comprise a compound of formula (I). These medicaments find use in therapy, in particular in the prophylaxis or treatment of the abovementioned pathologies.
According to another of its aspects, the present invention relates to pharmaceutical compositions containing, as active ingredient, at least one compound according to the invention. These pharmaceutical compositions contain an effective dose of a compound according to the invention and optionally one or more pharmaceutically acceptable excipients.
Said excipients are chosen according to the pharmaceutical dosage form and the desired mode of administration among the customary excipients which are known to persons skilled in the art.
In the pharmaceutical compositions of the present invention for oral, sublingual, subcutaneous, intramuscular, intravenous, topical, local, intratracheal, intranasal, transdermal or rectal administration, the active ingredient of formula (I) above, or its potential salt, solvate or hydrate, may be administered in a unit form for administration, as a mixture with conventional pharmaceutical excipients, to animals and to human beings for the prophylaxis or the treatment of the above disorders or diseases.
The appropriate unit forms for administration comprise the oral forms such as tablets, soft or hard gelatin capsules, powders, granules, chewing gums and oral solutions or suspensions, the forms for sublingual, buccal, intratracheal, intraocular or intranasal administration, or the forms for administration by inhalation, the forms for subcutaneous, intramuscular or intravenous administration and the forms for rectal or vaginal administration. For topical application, the compounds according to the invention may be used in creams, ointments or lotions.
For example, when a solid composition is prepared in the form of tablets, the main active ingredient is mixed with a pharmaceutical excipient, such as gelatin, starch, lactose, magnesium stearate, talc, gum arabic or the like. The tablets may be coated with sucrose, a cellulose derivative or other materials. The tablets may also be made by various techniques, direct compression, dry granulation, wet granulation or hot melt.
In order to obtain the desired prophylactic or therapeutic effect, the dose of active ingredient may vary between 0.1 and 200 mg per kg of body weight and per day. Although these dosages are examples of an average situation, there may be specific cases where higher or lower dosages are appropriate, such dosages also belong to the invention. According to the usual practice, the dosage appropriate for each patient is determined by the doctor according to the mode of administration, the weight and the response of said patient.
Each unit dose may contain from 0.1 to 1000 mg, preferably from 0.1 to 500 mg, of active ingredient in combination with one or more pharmaceutical excipients. This unit dose may be administered 1 to 5 times per day so as to administer a daily dosage of 0.5 to 5000 mg, preferably of 0.5 to 2500 mg.
The present invention, according to another of its aspects, also relates to a method for the prevention or treatment of the pathologies indicated above, which comprises the administration of a compound according to the invention, of a pharmaceutically acceptable salt, of a solvate or of a hydrate of said compound.
|
The present invention is directed to a compound of formula (I):
wherein Ar 1 , Ar 2 , Ar 3 , R1 and T are as defined herein, its preparation, pharmaceutical composition and uses as orexin 2 receptor antagonist.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 09/738,720 filed on Dec. 15, 2000 which claims priority to Swedish application serial no. SE 9904685-6 filed on Dec. 17, 1999.
FIELD OF THE INVENTION
[0002] The present invention relates to packet switching, more specifically to data stream decoding and data stream analyzing.
BACKGROUND OF THE INVENTION
[0003] In the field of data and computer communications there is an increasing need for high speed/high bandwidth products. Prior art references relating to packet switching and more specifically to data stream decoding and pertinent to the present invention include: U.S. Pat. No. 5,509,006, JP 6/276198, EP 767565, EP 953897, and U.S. Pat. No. 5,594,869.
[0004] The problem of extracting address information in a switch from a packet in a data stream is in the prior art solved by applying masks on the content of one or more delay lines to filter out the required information. One disadvantage with this approach is the difficulty to adjust the switch to new communication protocols, because the masks are hardware implemented. Another disadvantage with the prior art is that the data in the delay line is only accessible at a certain position or certain positions, instead of being available all the time they reside in the delay line.
[0005] Accordingly, it is an object of the present invention to provide a device for improved programmable datastream analysis in the context of packet switching. In the context of this document a datastream can be any type of data stream, e.g. a bytewise Ethernet datastream in a computer network, including an Ethernet packet with different combinations of contents.
SUMMARY OF THE INVENTION
[0006] The invention relates to a device for data stream analyzing. Said device is able to recognize different data streams and then start other processors or functionalities to store or check data in a data stream. Special features are: a compare processor, a compare instruction memory, a data stream pipeline, a multiplexer and a multiplexer control unit, making it possible to test packet data under program control using several instructions and under several clock cycles even though the data is moving forward in the pipeline and even though other bytes of data are entering the device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention will be described in detail below with reference to the accompanying drawings in which
[0008] FIG. 1 is a block diagram of the invention
[0009] FIG. 2 is a block diagram of the multiplexer control unit of FIG. 1 .
[0010] FIG. 3 is an interface overview of the invention
DETAILED DESCRIPTION OF THE INVENTION
[0011] The invention is preferably implemented as an integrated circuit (IC) having an electrical interface to the outside. The invention comprises a number of physical or logical units as illustrated in FIG. 1 , including;
a delayline 1 a multiplexer 2 a multplexer control unit 3 a compare processor 5 a compare instruction memory 4 a save engine 6 a bit save unit 7 a save instruction memory 8 a stream save unit 9 an address bus
[0022] When a data stream enters the device of the invention, it is passed through a delayline 1 , preferably a 23 shifts deep and 1 byte wide shift register. As long as a byte resides in the first 16 positions it can be accessed by the compare processor 5 , which basically will act as a packet parser. The compare processor 5 is responsible for decoding the packets. It is also connected to a compare instruction memory 4 which inherits the parsing code.
[0023] One characteristic property of the invention is that every incoming byte in the data stream is numbered with a tag. When the compare processor 5 asks for a specific tag the multiplexer control unit 3 delivers the byte located at the right position.
[0024] When the compare processor 5 has come to some kind of conclusion it might want to report something to a result field or an option field, see below. This is done by starting up a save sequence. A start address for a save sequence will be sent from the compare processor 5 to the save engine 6 . Said save engine 6 examine the incoming address and decides if it is a save regarding the result field or the option field. According to this decision the address is placed in either a bit save fifo register 61 or a stream save fifo register 62 respectively.
[0025] The bit save unit 7 has three functions: it can set bits in the result field, perform checksum control and length control.
[0026] The stream save unit 9 executes the instruction that saves the option field. Said stream save unit 9 also inserts the result field into the stream and regulates a number of control signals.
[0027] The delayline 1 preferably comprises a 23 shifts deep, 1 byte wide shift register. The 16 first positions of the shift register is reachable from the compare processor 5 through a multiplexer 2 . The two last positions are connected to the two save units 7 , 9 (bit save and stream save). The stream save unit 9 is actually only using the very last position, and only the bit save unit 7 needs the last two positions because the checksum control works with 16 bits at a time. There are five positions that are prevented from being accessed by the parsing function of the compare procesor 5 and by the save units 7 , 9 (bit save and stream save). The reason for a delay before the byte stream arrives to the save units 7 , 9 is that all start addresses sent from the compare processor 5 to the save units 7 , 9 are queued in a fifo register. Depending on how many save sequences in the queue and how long they are, this might in some extreme situations generate an error. This is because vital data already have passed through the delayline before a save sequence is started. The actual delay needed to secure that no such error occurs is 4*64=192 clock cycles. 64 is the maximum length of a save sequence and 4 is the maximum of start addresses waiting to be executed. However, simulations have shown that five delay cycles are enough, since all save sequences normally written are very short.
[0028] A characteristic function of the invention is that it automatically keeps track of where a specific byte has its location in the delayline. The programmer only needs to specify which tag, i.e. which number the byte has, where the first byte in a packet is number zero, the second is number 1 and so on. This is why every byte arriving to the delayline 1 should be tagged (numbered). The tagging operating could easily be done by just adding an extra field in every shift in the delayline 1 inheriting the byte's tag. But this is disadvantageous in two aspects. First, much silicon would be used to implement the extra field in the delayline 1 . Second, when the parser wants to look at a specific tag it would take a lot of time if every shift had to be searched to find the wanted tag.
[0029] Instead, the present invention has solved the above problem by making a part of the delayline multiplexable; said multiplexable part of the delayline preferably includes the 16 latest incoming bytes. Worst case for the length of a packet is 1 byte (erroneous), but since the first 12 bytes always contain the OSI Media Access Control address (MAC-address), no useful information can be extracted if the packet is shorter than 13 bytes. These packets will force the compare processor 5 to begin with the next packet at once and their DV (data valid) signal will be unset so the rest of the device or a switch will never see it. With a limit of at least two clock cycles (bytes) between different packets it is possible to guarantee that never more than two packets exist at the same time in the delayline 1 .
[0030] According to the ethernet standard the 1FG (Inter Frame Gap), which means the distance between packets, is at least 20 cycles, but a smaller distance is always desirable. E.g. a minimum distance of 6 cycles makes it possible to easily extend the device to be able to take care of SONET frames (An alternative ISO-OSI Layer 2 frame instead of ethernet).
[0031] FIG. 2 illustrates that the multiplex control unit 3 uses two identical Tag Units 32 , 33 (TU), one for each possible packet, a Controlling Statemachine 31 (CS) to control the TU:s 32 , 33 and a TU muliplexer 34 to choose which one of the TU:s 32 , 33 that the compare processor 5 is interested in. One TU includes a tagfield register 321 , and a lastfield register 322 , some adders and a simple statemachine 323 : The other TU 33 is identical. When a packet arrives, the tagfield register 321 starts to increment for every byte. When the DV signal becomes false again the tagfield register 321 stops counting and the lastfield register 322 starts to increment. The TU 32 sends an “end of packet” signal when the lastfield register 322 reaches the number of shifts in the delayline 1 . If the packet was shorter than 13 bytes a “too short” signal will be generated.
[0032] The position of a requested byte is located according to the expression
p= tagfield+lastfield−wanted_tag
[0033] In the above expression “p” is the position of the wanted byte in the delayline; “tagfield” is the value of the tagfield register ( 321 or 331 ); “lastfield” is the value of the lastfield register ( 322 or 332 ) and “wanted_tag” is the position of the wanted byte relative to the beginning of the packet.
[0034] A TU 32 , 33 also generates a ‘tag_error’ signal if the requested tag never will be available or ‘tag_soon’ if the requested tag has not arrived to the delayline yet.
[0035] The controlling statemachinc (CS) 31 is responsible for selecting a free TU ( 32 or 33 ) for an arriving packet and to pause the compare processor 5 when no new packets are available. The CS 31 will unselect a TU ( 32 , 33 ) when the TU generates an ‘end_of_packet’ signal. An unselected TU ( 32 , 33 ) will be reset to prepare it to receive the next incoming packet. The CS 31 is also controlling the TU multiplexer 34 to change its state every time the compare processor is asking for a new packet.
[0036] Referring again to FIG. 1 , a feature of the device according to the present invention is that the compare processor 5 and the compare instruction memory 4 together act as a programmable parser. The description of the full instruction set of said parser is not set forth herein, but some instruction types are mentioned below. The parser uses four registers 51 , 52 , 54 , 55 to fulfil its tasks.
One PC register 55 that holds the value of the program counter. One general register 52 . It can be used with instructions for arithmetic operations and for ‘IF_THEN_ELSE’ operations. One base register 54 . When the parser searches a tag, the value in the base register 54 is added to the searched tag value. This is used to be able to reuse instruction code for e.g. OSI Layer 3 frames, even if they are encapsulated in different OSI Layer 2 frames. One stack address register 51 used to store addresses when subroutines are called with ‘JUMP_SUBROUTINE’ type instructions. Accordingly, ‘RETURN’ type instructions copy the stack back to the PC 55 .
[0041] All instructions are executed in one clockcycle, except in two cases. This is possible because the compare processor unit receives two instructions every clockcycle from the compare instruction memory 4 which is of the double ported memory type. This features decreases the total amount of clock cycles needed for the compare processor 5 to parse a packet, thereby decreasing the needed size of the delayline. Some instructions are able to start save sequences. Said instructions have a field that tells what address in the save instruction memory 8 shall start the execution. Save address 0×00 will not generate a start of a save sequence.
[0042] The compare processor 5 must know when a new parsing is started so the registers 51 , 52 , 54 , 55 can be reset. Therefore, when parsing of a packet is done, there shall be a ‘jump_and_save’ instruction with jump adress 0×7f (=last compare instruction memory 4 address). When this is detected it resets and starts looking for a new packet. If the compare processor 5 gets the signal ‘too_short’ it is reset. Further, a ‘tag_soon’ signal pauses the processor 5 and a ‘tag_error’ signal forces it to begin with the next packet.
[0043] The save engine 6 takes the address sent from the compare processor 5 and determines if it is the start address of a bit save sequence or a byte stream sequence. Thereafter, the address together with the current value of the base register 54 is put in the specific fifo 61 , 62 , The value of the base register 54 is needed for all save instructions that are using tag numbers. When the device according to the invention is programmed, a constant is written to the save engine 6 to tell where bit save sequences end in the save instruction memory 8 . This feature exists because it is hard to tell how many instructions are needed to the different parts and it is more expensive to map two memories than one twice as big.
[0044] The bit save unit 7 writes to the result field 76 . The result field 76 preferably consists of 24 bits or 3 bytes. It is controlled by the save instruction memory 8 and orders other units to execute the instructions. The executing units are:
[0000] Checksum
[0045] The checksum unit 73 executes a checksum control instruction which performs a 16-bit one complement addition. The unit needs to know what tag to start the execution from (Tag) and how many bytes the checksum should cover (Length). If there are checksum errors (i.e. the sum differs from 0×FFFF) the unit writes to the result field 76 . Further, this block need the value of the base register 54 as it was when the compare processor 5 sent the start address of the current save sequence.
[0000] Bit
[0046] The bit unit 74 executes a bit save command which bitwise “xor”-ise one selected byte in the result field 76 with the data field. In other words, all bits which are set in the data field will invert the corresponding bit in the result field 76 . It is only possible to invert one specific bit one time per packet, this is because e.g. an OSI Layer 3 error could be found in many ways, but if the bit which indicate a Layer 3 error is set an even number of times, this would look like a correct Layer 3 packet in the result field 76 . The address field indicates which byte of the three possible bytes in the result field 76 , should be written to.
[0000] Length Error
[0047] The length error unit 75 is the most complex unit and investigates lengths in a packet and is used with one or more length control instructions. In a network there might occur packets that have been cut off. This causes many kinds of errors, e.g. if layer 4 is shorter than two bytes the result field 76 should indicate Layer 3 error but not Layer 2 error. The length error unit 75 consists of two identical checkboxes and one controller. A checkbox needs to know at which tag to start the measurement from, what kind of comparison it is supposed to perform (more, less, equal or not equal) and what length to match this comparison to. If a checkbox detects a length error, a field which is part of the instruction indicates which bit, of four possible bits in the results field 76 , should be written to. As with the checksum unit 73 , this unit 75 also needs the value from the base register 54 as it was when the compare processor 5 sent the start address of the current save sequence.
[0048] The stream save executing unit 9 has only one save instruction to handle, a byte stream save instruction. Said instruction is used to save to the option field and includes a start tag number, a length and an six bit wide address to tell were in the option field the selected bytes are to be written. Besides of this it also inserts the result field 76 as soon as all bit save instructions are executed.
[0000] Interface
[0049] The electrical interface of a preferred embodiment of the invention to the outside world is described in conjunction with FIG. 3 . It includes an input interface and an output interface. The input interface of the invention includes nine input terminals for a synchronous, eight bit wide, serial data stream, and a data valid (DV) signal, both used by the data that should be decoded. The input interface also includes a programming interface that comprises an 8-bit address bus, an 18-bit data bus, a chip select and a write enable signal for programming the two instructions. These 28 input terminals are used to program the invention after power on.
[0050] The output interface includes output terminals for a serial byte stream together with some control signals. The control signals include a data valid (1 bit), an option field address (6 bits), a store and a halt signal (1 bit each). The store signal tells if the current byte is to be stored in an option field, the halt signal together with the store signal tells if the stream out is the inserted result field. The address bus allows addressing in the option field.
[0051] A typical application for the present invention is for packet switching in a computer network together with a packet switch by extracting information, especially addresses, from the packet headers, because it is possible to test data using several instructions and under several clock cycles even though said data is moving forward in the delayline ( 1 ) and even though other bytes of data are entering the device. One of the features of the invention is that the decoding of the protocol is programmable. This is a major advantage because new or different types of protocols can be handled by just reprogramming the device. There will be no need for changing the hardware. This could save time and money for companies responsible for providing, maintaining and updating network switches.
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A device for data stream analyzing that is able to recognize different data streams and then start processors or functionalities to store or check data in a data stream. The device includes a processor means and a program memory, making it possible to parse a data stream in a way that is controlled by an interchangeable program. There will be no need for changing the hardware. This could save time and money for companies responsible for providing, maintaining and updating network switches. The device also includes a multiplexable data stream delayline for receiving the data streams, and multiplexing means for connecting different parts of the data stream to the processor.
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This is a continuation-in-part of Provisional Application Nos. 60/157,824, filed Oct. 5, 1999; 60/178,901, filed Jan. 28, 2000 and application Ser. No. 09/618,352, filed Jul. 19, 2000.
FIELD OF THE INVENTION
The present invention relates generally to medical devices, and more particularly to an apparatus and method for using an ultrasonic medical device operating in a transverse mode to remove occlusions from a blood vessel. The invention also relates to an apparatus and method of using balloon catheters emitting ultrasonic energy in transverse mode, to remove vascular occlusions.
BACKGROUND OF THE INVENTION
Vascular occlusions (clots or thrombi and occlusional deposits, such as calcium, fatty deposits, or plaque), result in the restriction or blockage of blood flow in the vessels in which they occur. Occlusions result in oxygen deprivation (“ischemia”) of tissues supplied by these blood vessels. Prolonged ischemia results in permanent damage of tissues which can lead to myocardial infarction, stroke, or death. Targets for occlusion include coronary arteries, peripheral arteries and other blood vessels. The disruption of an occlusion or thrombolysis can be effected by pharmacological agents and/or or mechanical means. However, many thrombolytic drugs are associated with side effects such as severe bleeding which can result in cerebral hemorrhage. Mechanical methods of thrombolysis include balloon angioplasty, which can result in ruptures in a blood vessel, and is generally limited to larger blood vessels. Scarring of vessels is common, which may lead to the formation of a secondary occlusion (a process known as restenosis). Another common problem is secondary vasoconstriction (classic recoil), a process by which spasms or abrupt closure of the vessel occurs. These problems are common in treatments employing interventional devices. In traditional angioplasty, for instance, a balloon catheter is inserted into the occlusion, and through the application of hydraulic forces in the range of ten to fourteen atmospheres of pressure, the balloon is inflated. The non-compressible balloon applies this significant force to compress and flatten the occlusion, thereby opening the vessel for blood flow. However, these extreme forces result in the application of extreme stresses to the vessel, potentially rupturing the vessel, or weaking it thereby increasing the chance of post-operative aneurysm, or creating vasoconstrictive or restenotic conditions. In addition, the particulate matter isn't removed, rather it is just compressed. Other mechanical devices that drill through and attempt to remove an occlusion have also been used, and create the same danger of physical damage to blood vessels.
Ultrasonic probes are devices which use ultrasonic energy to fragment body tissue (see, e.g., U.S. Pat. No. 5,112,300; U.S. Pat. No. 5,180,363; U.S. Pat. No. 4,989,583; U.S. Pat. No. 4,931,047; U.S. Pat. No. 4,922,902; and U.S. Pat. No. 3,805,787) and have been used in many surgical procedures. The use of ultrasonic energy has been proposed both to mechanically disrupt clots, and to enhance the intravascular delivery of drugs to clot formations (see, e.g., U.S. Pat. No. 5,725,494; U.S. Pat. No. 5,728,062; and U.S. Pat. No. 5,735,811). Ultrasonic devices used for vascular treatments typically comprise an extracorporeal transducer coupled to a solid metal wire which is then threaded through the blood vessel and placed in contact with the occlusion (see, e.g., U.S. Pat. No. 5,269,297). In some cases, the transducer is delivered to the site of the clot, the transducer comprising a bendable plate (see, U.S. Pat. No. 5,931,805).
The ultrasonic energy produced by an ultrasonic probe is in the form of very intense, high frequency sound vibrations which result in powerful chemical and physical reactions in the water molecules within a body tissue or surrounding fluids in proximity to the probe. These reactions ultimately result in a process called “cavitation,” which can be thought of as a form of cold (i.e., non-thermal) boiling of the water in the body tissue, such that microscopic bubbles are rapidly created and destroyed in the water creating cavities in their wake. As surrounding water molecules rush in to fill the cavity created by collapsed bubbles, they collide with each other with great force. This process is called cavitation and results in shock waves running outward from the collapsed bubbles which can wear away or destroy material such as surrounding tissue in the vicinity of the probe.
Some ultrasonic probes include a mechanism for irrigating an area where the ultrasonic treatment is being performed (e.g., a body cavity or lumen) to wash tissue debris from the area. Mechanisms used for irrigation or aspiration described in the art are generally structured such that they increase the overall cross-sectional profile of the probe, by including inner and outer concentric lumens within the probe to provide irrigation and aspiration channels. In addition to making the probe more invasive, prior art probes also maintain a strict orientation of the aspiration and the irrigation mechanism, such that the inner and outer lumens for irrigation and aspiration remain in a fixed position relative to one another, which is generally closely adjacent the area of treatment. Thus, the irrigation lumen does not extend beyond the suction lumen (i.e., there is no movement of the lumens relative to one another) and any aspiration is limited to picking up fluid and/or tissue remnants within the defined distance between the two lumens.
Another drawback of existing ultrasonic medical probes is that they typically remove tissue slowly in comparison to instruments which excise tissue by mechanical cutting. Part of the reason for this is that most existing ultrasonic devices rely on a longitudinal vibration of the tip of the probe for their tissue-disrupting effects. Because the tip of the probe is vibrated in a direction in line with the longitudinal axis of the probe, a tissue-destroying effect is only generated at the tip of the probe. One solution that has been proposed is to vibrate the tip of the probe in a transverse direction—i.e. perpendicular to the longitudinal axis of the probe,—in addition to vibrating the tip in the longitudinal direction. For example, U.S. Pat. No. 4,961,424 to Kubota, et al. discloses an ultrasonic treatment device which produces both a longitudinal and transverse motion at the tip of the probe. The Kubota, et al. device, however, still relies solely on the tip of the probe to act as a working surface. Thus, while destruction of tissue in proximity to the tip of the probe is more efficient, tissue destruction is still predominantly limited to the area in the immediate vicinity at the tip of the probe. U.S. Pat. No. 4,504,264 to Kelman discloses an ultrasonic treatment device which improves the speed of ultrasonic tissue removal by oscillating the tip of the probe in addition to relying on longitudinal vibrations. Although tissue destruction at the tip of the device is more efficient, the tissue destroying effect of the probe is still limited to the tip of the probe.
There is a need in the art for improved devices, systems, and methods, for treating vascular diseases, particularly stenotic diseases which occlude the coronary and other arteries. In particular, there is a need for methods and devices for enhancing the performance of angioplasty procedures, where the ability to introduce an angioplasty catheter through a wholly or partly obstructed blood vessel lumen can be improved. There is also a need for mechanisms and methods that decrease the likelihood of subsequent clot formation and restenosis.
SUMMARY OF THE INVENTION
The invention is directed to a method and an apparatus for removing occlusions in a blood vessel. The invention has particular application in removal of occlusions in saphenous vein grafts used in coronary bypass procedures, restoring these grafts to patency without damaging anastomosing blood vessels. The method according to the invention comprises inserting a probe member comprising a longitudinal axis into a vessel, positioning the member in proximity to the occlusion, and providing ultrasonic energy to the member. The device is designed to have a small cross-sectional profile, which also allows the probe to flex along its length, thereby allowing it to be used in a minimally-invasive manner. The probe, because it vibrates transversely, generates a plurality of cavitation nodes along the longitudinal axis of the member, thereby efficiently destroying the occlusion. A significant feature of the invention is the retrograde movement of debris, e.g., away from the tip of the probe, resulting from the transversely generated energy. Probes of the present invention are described in the Applicant's co-pending provisional applications U.S. Ser. Nos. 60/178,901 and 60/225,060 which further describe the design parameters for an ultrasonic probe operating in a transverse mode and the use of such a probe to remodel tissues. The entirety of these applications are herein incorporated by reference.
In one aspect, the invention relates to one or more sheaths which can be adapted to the probe tip, thereby providing a means of containing, focussing, and transmitting energy generated along the length of the probe to one or more defined locations. Sheaths for use with an ultrasonic medical device are described in the Applicant's co-pending utility application U.S. Ser. No. 09/618,352, the entirety of which is hereby incorporated by reference. The sheaths of the present invention also provide the user with a means of protecting regions of tissue from physical contact with the probe tip. In one embodiment of the invention the sheaths also comprise a means for aspiration and irrigation of the region of probe activity. In another embodiment of the invention, a plurality of sheaths are used in combination to provide another level of precision control over the direction of cavitation energy to a tissue in the vicinity of the probe. In one embodiment of the invention, the sheath encloses a means of introducing fluid into the site of the procedure, and a means for aspirating fluid and tissue debris from the site of the procedure. In a further embodiment, the probe tip can be moved within the sheath. In yet another embodiment, the irrigation and aspiration means, and the probe tip, can all be manipulated and repositioned relative to one another within the sheath. In another embodiment, the sheath is shaped in such a way that it may capture or grasp sections of tissue which can be ablated with the probe. In yet another embodiment, the sheath provides a guide for the probe tip, protecting tissues from accidental puncture by the sharp, narrow diameter tip, or from destruction by energy emitted radially from the probe during introduction of the probe to the site. The sheath may be applied to the probe tip prior to insertion of the probe into the patient, or the sheath can be inserted into the patient prior to the insertion of the probe. The sheath of the present invention can be used to fix the location of one or more shapes relative to the nodes or anti-nodes of a probe acting in transverse action. The location of the reflective shapes can amplify the acoustical wave thereby magnifying the energy. This allows for the use of very small diameter probes which themselves would not have the requisite structural integrity to apply and translate acoustical energy into sufficient mechanical energy to enable ablation of tissues. The reflective shapes can also focus or redirect the energy, effectively converting a transverse probe emitting cavitation energy along its length, to a directed, side fire ultrasonic device.
In another embodiment, the probe, which may or may not contain a probe sheath, is used in conjunction with an expandable balloon dilatation catheter, providing a means of resolving the occlusion without imparting stress, or inflicting stress injury to a vessel. The balloon catheter acts as a carrier means for guiding the probe wire to the desired site, and acts as a means to position the wire within the lumen of the vessel. With the balloon inserted within the confines of an occlusion, inflation of the balloon provides a means of continuous contact with the potentially irregularly shaped vessel lumen. Introduction of ultrasonic energy into the balloon by the transversely vibrating probe wire thereby results in uniform communication of energy to the regions of the occluded vessel in contact with the balloon. Since the balloon is inflated to much lower pressures than in traditional balloon angioplasty procedures, neither the occlusion or the vessel is compressed, thereby eliminating the problems of stress injury to the vessel. Likewise, as the ultrasound energy fragments the occlusion, the vessel is cleared of the problematic material, rather than simply compressing it into the vessel.
In one embodiment of the invention, a light transmitting element in inserted into the blood vessel along with, or after, the probe (with or without probe sheath) and balloon catheter. The light transmitting element is transmits optical data about the occlusion. In another embodiment of the invention, the probe/sheath and balloon catheter is used with such medical devices, such as a stent, stent graft, trocar, or other such intravascular devices. The invention is particularly useful in clearing occlusions within stents or other such devices where compression is undesirable or not warranted.
In another aspect of the invention, the probe, with or without a probe sheath, and with or without the balloon catheter, may be provided in a sharps container, in the form of a kit. A sharps container of the present invention is the subject of the Applicant's co-pending utility application U.S. Ser. No. 09/775,908, the entirety of which is hereby incorporated by reference. In yet another embodiment, the kit provides instructions, for example, instructions for assembling and tuning the probe, and the appropriate frequency range for the medical procedure. The kit may further comprise packaging whereby the probe, sheath, and balloon catheter are pre-sterilized, and sealed against environmental contaminants. In another embodiment, the container complies with regulations governing the storage, handling, and disposal of sharp medical devices, and used medical devices such as a sheath or balloon catheter.
DESCRIPTION OF THE DRAWINGS
In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.
In one embodiment, as shown in FIG. 1, the transverse mode ultrasonic medical device 1 comprises an elongated probe 6 which is coupled to a device providing a source or generation means for the production of ultrasonic energy (shown in phantom in the Figure as 66 ). The probe 6 transmits ultrasonic energy received from the generator along its length. The probe is capable of engaging the ultrasonic generator at one terminus with sufficient restraint to form an acoustical mass, that can propagate the ultrasonic energy provided by the generator. The other terminus of the probe comprises a tip 22 , which has a small diameter enabling the tip to flex along its longitude. In one embodiment of the invention, the probe diameter decreases at defined intervals 14 , 18 , 20 , and 22 . Energy from the generator is transmitted along the length of the probe, causing the probe to vibrate. In this embodiment, one of the probe intervals 18 has at least one groove 45 .
FIG. 2 shows an embodiment of the invention wherein the probe 6 is substantially contained within a cylindrical sheath 121 capable of modulating the energy omitted by an active probe, and shielding tissues from puncture from a sharp probe tip. The sheath 121 shown in this illustration has been modified such that one of the terminal ends of the sheath is substantially open, defining a fenestration or aperture 111 , which exposes the probe tip 22 and 23 . The terminus of the sheath 129 is shaped to provide a means for manipulating tissue to bring it into proximity with the probe 22 and 23 . Also shown in this embodiment is a second cylindrical sheath 108 which surrounds a portion of the first sheath 121 , and can be manipulated longitudinally along the first sheath to provide a means for modulating the exposure of the probe tip 22 and 23 , and thereby modulating the cavitation energy emitted by the probe to which the tissues will be exposed. The container of the present invention is capable of receiving and containing the probe or probe and sheath assembly.
FIGS. 3 a-f show dampening sheaths for an ultrasonic probe according to embodiments of the invention. FIG. 3 a shows a transverse mode probe according to one embodiment of the invention comprising the semi-cylindrical sheath 107 and a second sheath 108 . In this embodiment, the second sheath is cylindrical, and is capable of containing the first sheath 107 , as well as the probe 6 .
FIG. 3 b shows another embodiment of the invention wherein the sheath 121 comprises a cylindrical structure of a sufficient diameter to contain the probe 6 , visible for the purpose of illustration. The sheath 121 comprises at least one fenestration 111 , which allows the cavitation energy emitted from the probe tip to be communicated to an area outside the sheath, otherwise the energy is contained by the sheath.
FIG. 3 c shows an embodiment of the present invention wherein the hollow cylindrical sheath 121 has a plurality of arcutate fenestrations 111 .
FIG. 3 d shows an embodiment of the present invention wherein the probe 6 is contained within a sheath 121 which comprises a plurality of arcutate fenestrations 111 , and at least one acoustic reflective element 122 , which is adapted to the interior surface of the sheath.
FIG. 3 e shows an embodiment of the present invention comprising a sheath 121 further comprising two semi-cylindrical halves 109 , each half connected to the other by one or more connecting means 113 . The probe 6 is capable of being substantially contained within the sheath. The cavitation energy generated by the probe tip 22 is contained by the semi-cylindrical halves 109 , where they occlude the probe tip.
FIG. 3 f shows an embodiment of the present invention wherein the sheath further comprises at least two cylinders 104 , each cylinder connected to the other by at least one connecting means 113 . The probe 6 is capable of being substantially contained within the sheath. The cavitation energy generated by the probe tip 22 is contained by the cylinders 104 , where they occlude the probe tip.
FIG. 4 shows a longitudinal cross-section of a portion of an ultrasonic probe tip 22 and 23 according to one embodiment of the invention, comprising a central irrigation passage 17 and lateral irrigation lumens 19 , as well as external aspiration channels 60 .
FIG. 5 shows a transverse cross-section of a portion of the ultrasonic probe shown in FIG. 4 . In this embodiment, the probe 6 comprises a plurality of arcutate channels 60 that extend over the longitudinal length of the probe tip, providing a space for irrigation and or aspiration of tissue debris and fluid.
FIG. 6 a shows an embodiment of the invention wherein the probe tip 22 and 23 , is substantially contained within a sheath. The sheath comprises a fenestration 111 allowing communication of the cavitation energy emitted by the probe to the outside of the sheath. The interior of the sheath further comprises reflective elements 118 , shown as a plurality of planar surfaces that extend from the interior wall of the sheath into the lumen, thereby providing a means for focussing and redirecting cavitation energy emitted by the probe tip. In this embodiment, the terminus of the sheath 129 is shaped to provide a tissue manipulation means also illustrated in FIG. 5 . FIG. 6 b shows a similar embodiment, wherein the reflective elements 118 are arcutate, and the sheath further comprises a plurality of fenestrations 111 .
FIG. 7 shows the ultrasonic medical device comprising an ultrasonic probe for removal of an occlusion “O” from a blood vessel “By”. FIG. 7 a shows a portion of the probe 22 guided to the site of, and through the occlusion, using ultrasonic energy to fragment occlusion materials and clear a path through the occlusion. FIG. 7 b shows the occlusion within the blood vessel partially removed by action of the probe. FIG. 7 c shows complete removal of the occlusion as occlusion materials are degraded by the energy transmitted by the probe 22 of the ultrasonic medical device.
FIG. 8 shows the ultrasonic medical device comprising an ultrasonic probe and a sheath assembly for selectively ablating an occlusion “O” from a blood vessel “BV”. FIG. 8 a shows a sheath assembly consisting of a sheath 108 adapted to a portion of the probe 22 . The probe is positioned proximally to the site of, and through the occlusion, using ultrasonic energy to fragment occlusion materials and clear a path through the occlusion, while the sheath protects non-occluded areas of the blood vessel by partially shielding the probe. FIG. 8 b shows the occlusion within the blood vessel partially removed by action of the probe, while the sheath is retracted to maintain exposure of the probe at occlusion site as it is moved through the site. FIG. 8 c shows complete removal of the occlusion, as occlusion materials are degraded by the energy transmitted by the probe 22 of the device, while non-occluded areas of the blood vessel remain protected from the action of the probe.
FIG. 9 shows the ultrasonic medical device used in conjunction with a balloon catheter for removal of an occlusion “O” from a blood vessel “BV”. FIG. 9 a shows the deflated balloon catheter 91 adapted to a portion of a probe 22 . The probe guides the catheter to the site of, and through the occlusion, using ultrasonic energy to clear a path through the occlusion if necessary. FIG. 9 b shows the deflated balloon catheter 91 positioned within the vessel lumen at the site of the occlusion. FIG. 9 c shows an activated ultrasonic medical device wherein the expanded balloon catheter engages the occlusion, maintaining contact with the occlusion as it is degraded by the energy transmitted through the balloon.
FIG. 10 shows the ultrasonic medical device used in conjunction with a series of sheaths and a balloon catheter 91 . In FIG. 10 a, the invention of the present embodiment comprises a probe 22 with a terminal end 23 , substantially contained within a first sheath 107 of which the end distal to the probe tip 23 , is shown cut away for illustrative purposes. The balloon catheter is adapted to an inflation means (not shown), which may also comprise a means for monitoring and compensating for pressure fluctuation in the interior of the balloon. The probe and first sheath is substantially contained within a second sheath 121 , further comprising a series of fenestrations 111 along its longitude. The balloon catheter 91 , shown substantially deflated, surrounds the second sheath along part of its length. In this embodiment, the probe tip 23 is exposed to the vessel lumen and can provide a means for clearing a path through an occlusion for the introduction of a balloon catheter. In FIG. 10 b, the probe 22 and 23 is withdrawn such that the tip 23 , is contained within the sheath 121 . The first sheath 107 is retracted, by for example, articulation wires, thereby exposing the probe 22 to the lumen of the second sheath 121 . Activation of the probe results in the transverse generation of cavitation energy along the probe at multiple nodes. The energy is communicated from the probe to the lumen of the balloon catheter through the fenestrations 111 in the second sheath 121 . The energy can penetrate the walls of the balloon for direct communication to the occlusion.
DETAILED DESCRIPTION
The following terms and definitions are used herein:
“Anti-node” as used herein refers to a region of minimum energy emitted by an ultrasonic probe on or proximal to a position along the probe.
“Cavitation” as used herein refers to shock waves produced by ultrasonic vibration, wherein the vibration creates a plurality of microscopic bubbles which rapidly collapse, resulting in molecular collision by water molecules which collide with force thereby producing the shock waves.
“Fenestration” as used herein refers to an aperture, window, opening, hole, or space.
“Node” as used herein refers to a region of maximum energy emitted by an ultrasonic probe on or proximal to a position along the probe.
“Probe” as used herein refers to a device capable of being adapted to an ultrasonic generator means, which is capable of propagating the energy emitted by the ultrasonic generator means along its length, and is capable of acoustic impedance transformation of ultrasound energy to mechanical energy.
“Sharps” as used herein refers to an elongated medical instrument with a small diameter, for example, less than 2 mm. A “Sharps Container” as used herein is a container capable of retaining a sharp medical device or the sharp portion thereof, such that a handler is not exposed to the sharp portion of the device.
“Sheath” as used herein refers to a device for covering, encasing, or shielding in whole or in part, a probe or portion thereof connected to an ultrasonic generation means.
“Tissue” as used herein refers to an aggregation of cells that is substantially similar in terms of morphology and functionality.
“Transverse” as used herein refers to vibration of a probe at right angles to the axis of a probe. A “transverse wave” as used herein is a wave propagated along an ultrasonic probe in which the direction of the disturbance at each point of the medium is perpendicular to the wave vector.
“Tuning” as used herein refers to a process of adjusting the frequency of the ultrasonic generator means to select a frequency that establishes a standing wave along the length of the probe.
“Ultrasonic” as used herein refers to a frequency range of the electromagnetic spectrum above the range of human hearing, i.e., greater than about 20,000 Hertz up to about 80,000 Hertz.
The present invention provides an ultrasonic medical device operating in a transverse mode for removing a vascular occlusion. Because the device is minimally invasive and articulable, it can be inserted into narrow, tortuous blood vessels without risking damage to those vessels. Transverse vibration of the probe in such a device generates multiple nodes of cavitation energy along the longitudinal axis of the probe, emanating radially from these nodes. The occlusion is fragmented to debris approximately of sub-micron sizes, and the transverse vibration generates a retrograde flow of debris that carries the debris away from the probe tip.
The mode of vibration of the ultrasound probe according to the invention differs from the axial mode of vibration which is conventional in the prior art. Rather than vibrating exclusively in the axial direction, the probe vibrates in a direction transverse to the axial direction. As a consequence of the transverse vibration of the probe, the tissue-destroying effects of the device are not limited to those regions of a tissue coming into contact with the tip of the probe. Rather, as the probe is positioned in proximity to an occlusion or other blockage of a blood vessel, the tissue is removed in all areas adjacent to the multiplicity of energetic nodes being produced along the entire length of the probe typically in a region having a radius of up to about 2 mm around the probe. In this way, actual treatment time using the transverse mode ultrasonic medical device according to the invention is greatly reduced as compared to methods using prior art probes.
The number of nodes occurring along the axial length of the probe is modulated by changing the frequency of energy supplied by the ultrasonic generator. The exact frequency, however, is not critical and a ultrasonic generator run at, for example, 20 kHz is generally sufficient to create an effective number of tissue destroying nodes along the axial length of the probe. In addition, as will be appreciated by those skilled in the art, it is possible to adjust the dimensions of the probe, including diameter, length, and distance to the ultrasonic energy generator, in order to affect the number and spacing of nodes along the probe. The present invention allows the use of ultrasonic energy to be applied to tissue selectively, because the probe conducts energy across a frequency range of from about 20 kHz through about 80 kHz. The amount of ultrasonic energy to be applied to a particular treatment site is a function of the amplitude and frequency of vibration of the probe. In general, the amplitude or throw rate of the energy is in the range of 150 microns to 250 microns, and the frequency in the range of 20-80 kHz. In the currently preferred embodiment, the frequency of ultrasonic energy is from 20,000 Hertz to 35,000 Hertz. Frequencies in this range are specifically destructive of hydrated (water-laden) tissues and vascular occlusive material, while substantially ineffective toward high-collagen connective tissue, or other fibrous tissues such as, for example, vascular tissues, or skin, or muscle tissues.
The amount of cavitation energy to be applied to a particular site requiring treatment is a function of the amplitude and frequency of vibration of the probe, as well as the longitudinal length of the probe tip, the proximity of the tip to a tissue, and the degree to which the probe tip is exposed to the tissues. Control over this last variable can be effectuated through the sheaths of the present invention.
Sheath materials useful for the present invention include any material with acoustical or vibrational dampening properties capable of absorbing, containing, or dissipating the cavitation energy emitted by the probe tip. Such materials must be capable of being sterilized by, for example, gamma irradiation or ethylene oxide gas (ETO), without losing their structural integrity. Such materials include but are not limited to, plastics such as polytetrafluoroethylene (PTFE), polyethylene, polypropylene, silicone, ultem, or other such plastics that can be used for medical procedures. Ceramic materials can also be used, and have the added benefit that they may be sterilized by autoclaving. Combinations of the aforementioned materials can be used depending on the procedure, for example as in the sheath of FIG. 5, a ceramic sheath 121 can be used in combination with a moveable PTFE outer sheath 108 . Alternatively a single sheath may employ two or more materials to give the desired combination of strength and flexibility, for example, the sheath may comprise a rigid ceramic section distal to the probe tip 23 and a more flexible plastic section proximal to the tip, capable of flexing with the probe 22 . In the currently preferred embodiment of the invention, PTFE is used to fabricate a strong, flexible, disposable sheath that is easily sterilized by irradiation or ETO gas.
The length and diameter of the sheath used in a particular operation will depend on the selection of the probe, the degree to which the probe length will be inserted into the subject, and the degree of shielding that is required. For example, in an application whereby vascular occlusive material is removed with the ultrasonic probe of the present invention, from a vessel deep inside the body of a patient, the sheath must be of a sufficient length to protect the vascular tissue from the surgical insertion point to the site of the operation, of a sufficient outside diameter to facilitate insertion of the sheath into the vessel, and a sufficient inside diameter capable of accepting the probe. By contrast, for clearing occlusions from, for example, a hemodialysis graft, the probe useful for such a procedure would be significantly shorter and as such, so would the sheath. The exact length and diameter of the sheath will be determined by the requirements of the medical procedure. Similarly, the position and size of the sheath aperture 111 , or number and positions of the fenestrations 111 , or the addition of a bevel on the sheath terminus 129 , will likewise be determined by the type of procedure, and the requirements of the particular patient.
A particular advantage of the ultrasonic probe operating in transverse mode is that the efficient cavitation energy produced by the probe disintegrates target tissue to small particles of approximately sub-micron diameter. Because of the operation of the probe, tissue debris created at the probe tip 23 , is propelled in a retrograde direction from the probe tip. Accordingly, another embodiment of the invention, provides at least one aspiration channel which can be adapted to a vacuum or suction device, to remove the tissue debris created by the action of the probe. The aspiration channel can be manufactured out of the same material as the sheath provided it is of a sufficient rigidity to maintain its structural integrity under the negative pressure produced by the aspiration means. Such an aspiration channel could be provided inside the lumen of the sheath, or along the exterior surface of the sheath, or the sheath itself may provide the aspiration channel. One embodiment of this is shown in FIGS. 6 and 7, whereby the probe 22 comprises at least one aspiration channel 60 , and aspiration of tissue debris is effectuated along the probe length between the interior surface of the sheath and the exterior surface of the probe, as directed by the aspiration channels.
In another embodiment, the present invention comprises an irrigation channel. The sheath is adapted to an irrigation means, and the sheath directs fluid to the location of the probe 22 . The irrigation channel can be manufactured out of the same material as the sheath provided it is of a sufficient rigidity to maintain its structural integrity under the positive pressure produced by the flow of fluid produced by the irrigation means. Such an irrigation channel could be provided inside the lumen of the sheath, or along the exterior surface of the sheath, or the sheath itself may provide the aspiration channel. Using the sheath itself to provide the irrigation, there is an added benefit that the probe 22 is cooled by the fluid.
In yet another embodiment, the sheath of the present invention further comprises both an irrigation and an aspiration channel. As in the above embodiments, the channels may be located within the sheath lumen, or exterior to the sheath, or a combination of the two. Likewise, the sheath lumen itself may provide either an irrigation or aspiration channel, with the corresponding irrigation or aspiration channel either contained within or external to the sheath. In another aspect of the invention, the sheath comprises a means for directing, controlling, regulating, and focussing the cavitation energy emitted by the probe, an aspiration means, an irrigation means, or any combination of the above.
Another embodiment of the invention comprises a means of viewing the site of probe action. This may include an illumination means and a viewing means. In one embodiment, the sheath of the present invention comprises a means for containing or introducing (if external to the sheath) an endoscope, or similar optical imaging means. In another embodiment of the invention, the ultrasound medical device is used in conjunction with an imaging system, for example, the non-ferrous probes are compatible with MRI, or ultrasound imaging—in particular color ultrasound. In this embodiment, the action of the probe echogenically produces a pronounced and bright image on the display. The sheath in this embodiment shields the probe, thereby reducing the intensity of the probe image and enhancing the resolution of the surrounding tissues. In another embodiment of the invention (not shown), the probe is used with an optical system. In one embodiment, the probe is inserted into a body cavity or lumen along with a light transmitting element for transmitting light from a light source and for receiving light and transmitting received light to a detector. Light from a light source (e.g., a laser) is transmitted through the light transmitting element, illuminating the area surrounding the probe 6 , and light transmitted back through the light transmitting element (e.g., from tissue in the vicinity of the probe) is detected by the detector. In one embodiment of the invention, the light transmitting element is an optical fiber, while in another embodiment, the light transmitting element is a plurality of optical fibers. The light transmitting element can be a part of the probe or can be inserted into a body cavity independently of the probe. In one embodiment of the invention, a sleeve is attached to the probe and the light transmitting element is held within the sleeve. In one embodiment, the detector is a human being (e.g., a physician or lab technician) and light is monitored using a viewing element, such as an eyepiece (e.g., as in a microscope coupled to the light transmitting element). It is preferred that the viewing element is not connected to a part of the ultrasonic medical device which is subject to vibration, to reduce manipulation of the viewing system to a minimum. In another embodiment of the invention, the detector is in communication with a processor and converts optical signals from the light transmitting element to data relating to the tissue in the vicinity of the probe.
In one embodiment, as shown in FIG. 8, the sheath comprises a surface that is capable of manipulating tissues near the site of the probe. In this aspect, the terminus of the sheath may be closed, such that the sheath insulates tissues from the destructive energy emitted by the probe and can be used to push tissues away from the aperture 111 , thereby allowing proximal tissues to be exposed to the probe 22 and 23 . Alternatively, the sheath comprises a beveled or arcutate surface at the sheath terminus 129 , capable of providing a means for hooking, grasping, or otherwise holding a tissue in proximity to the probe 22 and 23 . In another embodiment, the sheath provides a means for introducing a surgical device, for example, flexible biopsy forceps, capable of manipulating tissues into a tissue space, such that the surgical device can hold the tissue in proximity with the probe.
In one aspect of the invention, as shown in FIG. 5, the sheath comprises an inner sheath 121 and an outer sheath 108 . The outer sheath may be connected to an retraction trigger (not shown), by one or more articulation means, such as wires, which is capable of moving the outer sheath with respect to the inner sheath. Each wire comprises a first end and a second end. The first end is affixed to the outer sheath 108 , while the second end is affixed to a retraction trigger. When the outer sheath 108 is slid back away from the terminus of the inner sheath 121 the tissues are exposed to cavitation energy emitted by the probe. Another aspect of this is referred to in FIG. 10, where the first sheath 107 , is adapted to articulation wires (not shown in the illustration). In this embodiment, moving the sheath exposes the probe to the lumen of a second sheath 121 , comprising fenestrations which allow communication of the energy emitted from the probe to the lumen of a balloon catheter 91 . In this aspect, a probe can be operational without inflating the balloon catheter until movement of the first sheath exposes the probe, thereby allowing the probe to penetrate occlusions that would otherwise prevent placement of the balloon catheter without first clearing a site for placement within the occlusion, and thereby reducing the number of steps in a surgical procedure.
In another embodiment, the probe and sheath are flexible. Articulation wires (not shown) comprising a first end and a second end, are connected to the sheath and to an articulation handle. When the articulation handle is manipulated, for example, pulled axially inward, the flexible sheath will bend or articulate in a bending or articulation direction A, thereby causing the ultrasonic probe to bend or articulate in articulation direction A. In this way, the ultrasonic probe can be used to reach locations which are not axially aligned with the lumen or vessel through which the sheath and probe are inserted. One aspect of the invention uses such an articulable sheath to direct placement of a probe and a balloon catheter to a surgical site.
In yet another embodiment, the sheaths of the present invention may be provided along with an ultrasonic probe in the form of a kit. In this aspect, the probe for a particular surgical procedure is provided along with the correct sheath, as well as instructions for assembling and tuning the probe, and the appropriate frequency range for the procedure. The probe and sheath may be packaged preassembled, such that the probe is already contained within the sheath and the respective position of the probe within the sheath is optimized such that any reflective elements in the sheath would be correctly aligned with the prospective position of the nodes for a given frequency, the kit further comprising instructions for the appropriate frequency. The kit may further comprise packaging whereby the probe and sheath are pre-sterilized, and sealed against contaminants. In another embodiment, the probe and sheath is provided in a container that complies with regulations governing the storage, handling, and disposal of sharp medical devices. Such a container is capable of receiving and securing the probe and sheath before and after use. In one aspect, the sharps container provides a means of affixing the probe and sheath assembly to an ultrasonic medical device without direct manipulation of the probe and sheath assembly, and a means for removing the assembly from the ultrasonic medical device after use. In one aspect, the kit comprises a probe and sheath assembly contained within a sterile sharps container that further comprises a single use locking means, whereby the probe and sheath assembly is affixed to the ultrasonic medical device solely through the sharps container, are removed from the device solely through the container, and once removed can not be re-extracted from the sharps container.
EXAMPLES
Example 1
Removing Occlusions Using An Ultrasonic Medical Device and a Balloon Catheter
In one embodiment of the invention, the transverse mode ultrasonic medical device, is used in a procedure to remove an occlusion from a small diameter vessel (e.g., a native vessel, or a grafted vessel). In one embodiment, device is used in a method to reduce or eliminate an occlusion of a saphenous vein graft (e.g., such as used in a coronary bypass procedure).
A transverse mode ultrasonic probe is selected by the surgeon who will perform the procedure. The probe of the present invention further comprises a plurality of sheaths adapted to the probe, and a balloon catheter operably attached to one of the sheaths, all incorporated within a sharps container, and the container further sealed inside a sterile package, for example, a plastic bag. The user removes the container from the package and attaches the probe to the ultrasonic medical device by applying the threaded end of the probe to the transducer portion of an ultrasonic medical device. The probe, sheaths, and balloon catheter are securely held within the container, and the user rotates the container to affix the probe, sheaths, and catheter to the ultrasonic medical device. The user engages a lever which articulates the side A first locking assembly, thereby disengaging the probe from the first locking assembly. The probe, sheaths, and catheter can now be withdrawn from the container. The first locking assembly, once articulated, is engaged and held stationary by a second locking means, thereby preventing further use of the first locking assembly on this side A of the container with a probe. Articulation wires attached to one of the sheaths, are connected to a trigger assembly so the first sheath can be moved relative to the second sheath and the probe. One terminus of the balloon catheter is connected to an inflation means that may further comprise a means of monitoring and adjusting for pressure changes in the balloon lumen.
A small incision is made into the chest of a patient, and the vein graft is visualized using routine imaging technology. The probe, sheaths, and balloon catheter assembly is introduced into a vessel near the site of the occlusion, by way of, for example, a trocar or other vascular introducer. The probe assembly is guided to the site of the occlusion. The probe may be operably emitting energy, but the position of the first sheath relative to the probe and second sheath prevents cavitation energy from the probe from entering the balloon catheter, and the exposed probe terminus allows for introduction of the assembly, specifically the balloon catheter into the interior of the occlusion, as the occlusion is fragmented around the probe. The balloon catheter is inflated to greater than ambient pressure, such as for example, 1.5 atmospheres, so that the balloon is in contact with the occlusion but does not exert a high degree of compressive force on the occlusion or the vessel wall. The transversely vibrating probe is exposed to the lumen of the balloon by articulation of the first sheath. Cavitation energy from the probe is transmitted to the occlusion through the polymer walls of the balloon, thereby fragmenting the occlusion. As the occlusion is destroyed, allowing expansion of the balloon, the pressure drop is sensed and compensated for, by the inflation means, thereby the balloon re-engages the surface of the occlusion. The process continues for an appropriate length of time determined by the surgeon. When the procedure is completed, the balloon catheter is deflated, and the catheter, sheaths, and probe are withdrawn from the patient. The insertion device is removed, and the vascular tear, and surgical incision are sutured.
When the user completes the surgical procedure, and the probe apparatus is no longer required, the user inserts the probe, sheaths, and balloon catheter into side B of the container. The user engages a lever which articulates the side B first locking assembly, which, once articulated, is engaged and held stationary by a second locking means, thereby preventing further articulation of the side B first locking assembly. This first locking assembly engages the probe, thereby securing it. The user removes the probe assembly from the transducer of the medical device by applying counter-rotational torque to the container, thereby unscrewing the probe from the device. The used probe and assembly is permanently engaged by and contained within the container, and can be disposed of in compliance with the provisions governing the disposal of medical waste. Because the probe assembly is contained by the invention, the sharp probe tip does not present a safety hazard, and can be safely handled and disposed of as medical trash.
Example 2
Clearing Occlusions from a Hemodialysis Graft
In another embodiment, the invention can be used to clear occlusions from and restore the patency of a hemodialysis graft. The graft will not require shielding from ultrasonic energy, or the use of a balloon catheter as in example 1. A probe is selected and affixed to the ultrasonic transducer in the manner previously described, through the use of the container. The probe is withdrawn from the container, and inserted into the lumen of the hemodialysis graft. In one embodiment, the probe is directly introduced into the hemodialysis graft. In another embodiment, the probe is inserted using a trocar or other vascular insertion device, such as for example, the insertion device of Applicant's utility application Ser. No. 09/618,352. Application of ultrasonic energy causes the probe to vibrate transversely along its longitude. Occlusive materials, such as for example a thrombus, are fragmented by the action of the probe. When the graft has been returned to patency, the probe is withdrawn. The probe is removed from the device with the sharps container.
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 as claimed. Accordingly, the invention is to be defined not by the preceding illustrative description but instead by the spirit and scope of the following claims. The following references provided include additional information, the entirety of which is incorporated herein by reference.
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A method for removing an occlusion is provided comprising introducing a transverse mode ultrasonic probe into a blood vessel, positioning the probe in proximity to the occlusion, and transmitting ultrasonic energy to the probe, until the occlusion is removed. The probe has a small cross-sectional lumen and is articulable for navigating in a tortuous vessel path. The probe can be used with acoustic and/or aspirations sheaths to enhance destruction and removal of an occlusion. The probe can also be used with a balloon catheter. The probe, sheaths, and catheter can be provided in a sharps container which further provides a means of affixing and detaching the probe from an ultrasonic medical device.
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The following is a continuation-in-part of U.S. patent application Ser. No. 031,103, filed March 26, 1987
BACKGROUND OF THE INVENTION
The invention relates to an apparatus for producing a plasma and for the treatment of substrates therein, with a microwave generator, a chamber to contain a gas, a magnet system for producing local electron-cyclotron resonances, and with a substrate for coating in the chamber.
In numerous fields of technology it is necessary to apply very thin coatings of pure substances to certain objects. An example is window glass which is provided with a thin coating of metal or metal oxide in order to filter certain wavelength ranges out of sunlight. In semiconductor technology, thin coatings of one or more substances are often applied to a substrate. It is especially important that the thin coatings not only be pure, but also that they be precisely measured out so that the coating thicknesses--and, in the case of coatings of chemical compounds, their composition--will be accurately repeatable. These coating thicknesses are, as a rule, between two and several thousands of nanometers.
A variety of methods are known for applying thin coatings to films, glass and other substrates. In a first method, the thin coating is applied by chemical or electrochemical deposition, while in a second method the coating is applied by evaporation in a vacuum. With evaporation it is difficult to provide large areas with very thin coatings with the required uniform precision and repeatability, and consequently a third method, known as the sputtering or cathode spraying process, is used. For the deposition of a thin coating from the gas phase, sputtering is, of course, unsuitable.
To be able to deposit a pure substance or a chemical compound from the gaseous phase, the substance or compound is converted to the plasma state. The radicals formed in the plasma deposit themselves on the substrate. For the production of such a plasma, different forms of electrical energy can serve. For example it is possible to use direct currents, low-frequency alternating currents or corona discharges for the production of plasmas. Especially advantageous is the production of plasma by microwaves, because in this case no electrodes are needed, which can contaminate and become ablated, and because the plasma produced by microwaves has a greater density of ions and radicals and therefore can be kept at a higher pressure than the plasma produced by other methods. Furthermore, the chemical structure of starting monomers can be preserved at least partially. Lastly, the microwave plasma is also favored for the establishment of cold cathode ion sources.
It is true that usually only small volumes of plasma can be produced by microwaves, because the apparatus by which the microwave energy is delivered to the plasma--e.g., antennas, waveguides and cavity resonators--do not permit the production of large volumes of plasma. To produce a gas plasma, the delivered electrical field strength must exceed the electrical breakdown field strength of the gas. Since the breakdown field strength increases with increasing the pressure, high electrical field strengths are necessary at high pressures.
An apparatus for the production of plasmas by means of electromagnetic radiation is known, with which high field strengths are produced (U.S. Pat. No. 3,814,983).
In this apparatus a delay line, i.e., a microwave conductor of low group velocity ("slow wave structure") is used for the purpose of feeding the electrical energy to the plasma, the energy source being located outside of the receptacle and its electrical field passing through the receptacle wall. This delay line consists of a "semiradiating" system about 90 cm long, which operates in the degenerate π/2 mode or close to the degenerate π/2 mode. Operation in the vicinity of the band edge, i.e., either in the degenerate π/2 mode or in the π mode, leads to especially strong electrical fields in the vicinity of the delay line. The reason for this lies in the circumstance that the electrical field strength is inversely proportional to the group velocity of the wave, which in the vicinity of the edge of the band assumes a very small value. Furthermore, in this system the electrical field strength decreases with the distance perpendicular to the plane of the delay line. It is true that with this apparatus no large-volume plasmas with a very large, uniform plasma zone can be produced. It follows that the rate of deposit of polymers is irregular across the entire substrate width in the known apparatus. Moreover, interactions take place between the waves, which occur in the delay line, in the window dielectric and in the plasma; i.e., poorly understood interferences develop, which adversely effect the configuration of the plasma zone.
To equalize the rate of deposition in the case of polymers it has already been proposed, in an apparatus according to U.S. Pat. No. 3,814,983, that, in addition to the known delay line, at least a second elongated delay line be disposed on the same side of the substrate (German Federal Pat. 31 47 986). But this "crossed structure" arrangement has the disadvantage that the strongest plasma burns directly at the inside of the microwave window where the microwave is injected, and this results in an especially great and undesirable coating of this window.
Furthermore, an apparatus is known whereby a plasma is produced by means of a high-frequency wave which is injected into a waveguide in which a glass tube is situated in which the plasma is produced (German Federal OS 31 44 016), to which U.S. Pat. No. 4,438,368 corresponds. Around the plasma producing tube there is in this case provided a coil which produces a magnetic field along the axis of the glass tube. At a circuit frequency ω of the high-frequency field, and a magnetic flux density B, the electron-cyclotron resonance frequency will be ω=e ×B/m. At this resonance frequency the coupling of the high-frequency wave to the plasma electrons is especially strong. It is a disadvantage even in this known device, however, that only relatively small plasma zones can be produced. Furthermore, the glass tube easily takes on coatings deposited from the gas phase.
A microwave plasma source is also known, which has a vacuum chamber that serves as the discharge chamber (U.S. Pat. No. 4,433,228). The microwave energy in this case is fed into the discharge chamber through a microwave propagation path.
Outside of the discharge chamber and the microwave propagation path permanent magnets are provided, which serve for the guidance of the plasma produced by the microwave. The magnetic fields of these permanent magnets do not, however, permit cyclotron resonance of the plasma electrons in a defined area of a treatment chamber.
Another known microwave plasma source is largely the same as the plasma source according to U.S. Pat. No. 4,438,368, but an additional magnet coil is provided behind the substrate that is to be treated (Kimura, Murakami, Miyake, Warabisako, Sunami and Tokuyama: "Low Temperature Oxidation of Silicon in a Microwave-Discharged Oxygen Plasma", J. Electrochem. Soc., Solid-State Science and Technology, Vol. 132, No. 6, 1985, pp. 1460 -1466, FIG. 1). An especially interesting application for these known plasma sources might be, for example, the coating of searchlight reflectors with aluminum and a plasma-polymerized protective coating. Heretofore this coating has been performed in so-called batch coaters, using a direct-current plasma, a hydrophilization of the surface being performed in some cases by the addition of oxygen.
Also known is the depositing of silane and N 2 O for the purpose of producing SiO 2 coatings containing hydrogen. In this case high-frequency plasmas are used, as a rule (cf. D. P. Hess: J. Vac. Sci. Technol. A, 2, 1984, 244). To optimize the quality of the deposited film in the broadest sense, however, very high flows of N 2 O are required in proportion to silane, for example of 20 : 1 to 100 : 1 (cf. E. P. G. T van de Ven, Solid State Technol. 24, 1981, 167). Typical deposition rates range around 10 mm/min.
Apparatus is provided whereby it will be possible on the one hand to produce a uniform, large-volume plasma, and on the other hand to keep the plasma away from the microwave window.
According to the inventive process, it is possible to provide a transparent coating of SiO x , where 1 <×<2, to a substrate, especially a surface coated with aluminum. This is accomplished by introducing a hydrogen silicide gas into a chamber, as well as a second reactive gas consisting of oxygen or an oxygen containing compound. The chamber is exposed to microwaves and a magnetic field of sufficient strength to form a plasma of both gases in a region thereof. A substrate in said region is thus coated with SiO x , x being determined by the ratio of gases admitted.
The advantage achieved with the invention consists especially in the fact that large-area, uniform plasmas can be produced. Another advantage is that no deposits form on the entry window. These advantages are due to the fact that the magnetic field produced by the magnet systems is strong enough, at least in some areas, to permit a so-called electron-cyclotron resonance. Use is made of the fact that the electrical field strength that is necessary for the ignition of the plasma in a region in which the electron cyclotron resonance can take place is considerably smaller than in a region free of a magnetic field. Through the localization of the magnetic field sufficient for the electron cyclotron resonance, it is thus possible also to produce a corresponding localization of the plasma production. Furthermore, the apparatus according to the invention is especially suitable for the coating of substrates moving in a continuous linear manner.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a diagrammatic representation of a first embodiment of the invention,
FIG. 2 is a diagrammatic representation of a second embodiment of the invention,
FIG. 3 is a cross section of the embodiment shown in FIG. 1,
FIGS. 4a-e represent various permanent magnet arrangements,
FIG. 5 shows a distributor for a microwave,
FIG. 6 shows an arrangement for the coating of materials that can be wound on spools,
FIG. 7 shows a microwave transmitter system,
FIG. 8a-b represent a permanent magnet arrangement and a substrate that is to be coated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a plan view of a first variant of the invention. In a housing 1, which can be evacuated through a connection 2, there is disposed a linearly movable support 3 with a substrate that is to be coated. The coating is performed by means of a gas which is fed into a chamber 5 through an inlet connector 4 and is there ionized. The chamber 5 has walls of metal, of which walls 6, 7, 12 and 13 can be seen in FIG. 1. The lateral walls 6 and 7 have each a mesh 8, 9, which is permeable to microwaves and which assures the transparency of the chamber 5 for a gas exchange. Also provided in the chamber 5 is a rotatable metal reflector 10 which is in the form of a paddle wheel. Behind the substrate support 3 there is disposed a magnet system 11 which is situated between two metal boundary walls 12 and 13. Opposite this magnet system 11 is a microwave window 14, preferably of quartz glass, through which is microwaves from a horn radiator 15 enter into the gas chamber 5. This horn radiator 15 is in turn connected to a microwave conductor 16 which in turn is connected to a microwave transmitter which is not represented. The microwave power immediately behind the microwave window 14 is made such that it does not result in spontaneous ignition of the plasma in the window area.
In the horn radiator 15, which rests on a flange 22, a rotatable metal reflector 17 is disposed, and rods 18 of metal or of a dielectric are disposed opposite the reflector so as to influence the field distribution. The housing 1 is sealed off at both ends by pressure chambers 19 and 20 which serve as seals for the substrate support 3. The operation of the apparatus represented in FIG. 1 is as follows:
The microwave power radiated in the form of a lobe by the horn radiator 15 is injected into the chamber 5 formed by the metal walls and repeatedly reflected on the walls 6, 7, 12 and 13 and on the substrate support 3. This causes a number of standing waves with nodes and crests in different positions to form in chamber 5, if for the moment the absorption of the waves by the plasma is disregarded. The great number of standing waves is also referred to as a multimode system. The superimposition of many individual vibrations results in a wave field which is substantially more uniform than the lobe radiated by the horn radiator 15. An additional mixture of waves or modes can be achieved by the rotating metal reflectors 10 and 17 which are like wave agitators, so to speak.
Essential for the invention is the magnet system which, in the example of FIG. 1, is disposed behind the substrate support 3. It is by means of this magnet system that the electron-cyclotron resonance is produced. The gas particles ionized by the microwaves are drawn by the Lorenz force into a path curving around the magnetic lines of force. The frequency of the rotation of a charged particle in a homogeneous magnetic field is independent of its radius of curvature if the velocities are not too great, and it depends only on the specific charge of the particle and the magnetic flux density. Thus, the known cyclotron resonance frequency applies: ##EQU1## wherein f is the frequency of rotation of the particle, e o is the particle's charge, m the mass of the particle and B the magnetic flux density. In the case of a microwave frequency of 2.45 GHz coming from the horn radiator 15, in order to achieve the electron-cyclotron resonance frequency, a magnetic flux density of B =0.088 Vs/m 2 =800 Gauss is necessary in order to create such conditions in the plasma chamber 5 that the frequency of rotation of an electron about the lines of force of the magnetic system will be in phase with the exciting frequency of the microwave. The positive and negative half-waves of the electrical field of the microwave are situated relative to the momentary position of the electron such that it is always accelerated. In this manner it is possible, as it is known in cyclotron technology, to accelerate electrons to very high energies as long as care is taken that these electrons do not collide with residual gas particles. For further details on the interaction between plasma and electromagnetic fields refer to the related technical literature (e.g., Bergmann/Schafer, Lehrbuch der Experimentalphysik, Vol. IV, part 2, Aufbau der Materie, 1975, p. 1429 ff.).
In the case of the invention it is not the object to prevent collisions of the electrons with gas particles in order to bring the electrons to a high energy level; instead, such collisions are even desirable in order to produce radicals and ions by collision. In the case of a very frequent collision of electrons and gas particles, however, one can scarcely speak any more of a cyclotron resonance, because for this at least one complete revolution of the electrons has to be present before the collision takes place. This minimum of one revolution is achieved if the pressure of the gas is not all too high. As experiments have shown, the best results are obtained at a gas pressure in the 10 -3 mbar range.
The magnetic flux density necessary for cyclotron resonance in coupling to a microwave of 2.45 GHz is, as mentioned, 0.088 Tesla. Permanent magnets especially suited for the production of such a flux density have proven to be high-power permanent magnets such as CoSm or Nd-Fe-B magnets. If the said permanent magnets are used in the magnet system of FIG. 1, a cyclotron resonance is obtained in the region 21 represented in solid lines. Consequently the plasma is ignited in this region, i.e., there is no plasma present at the window 14 that will result in a deposit thereon. With the invention it is therefore possible to locate the plasma where it is wanted, namely at the substrate support 3.
For a number of applications, however, it is a disadvantage in this case that only largely planar substrates can be coated, because for practical reasons the zone 21 of cyclotron resonance cannot be produced much farther away than about 20 mm above the magnet poles.
One possibility for getting around this disadvantage is shown in the apparatus of FIG. 2. In this apparatus a plasma is produced in front of the substrate support 3, so that even decidedly three-dimensional substrates can be coated. The magnet arrangement here consists of two systems 24 and 25 which are arranged in symmetry with an imaginary straight line along the axis of the waveguide 16 and of the horn radiator 15. In this case two cyclotron resonance regions 26 and 27 form, which serve as ignition zones for the plasma. The two metal boundary walls 12 and 13 according to FIG. 1 are replaced in FIG. 2 by a single boundary wall 23.
In FIG. 3 the apparatus of FIG. 1 is represented in a cross section taken along line III-III. It can be seen that several rods 18 have been screwed to different depths in the horn radiator 15. With these rods 18 the microwave field can be influenced in the sense that it can be controlledly curved. The mesh 9 is now plainly visible beside the microwave agitator 10. Openings 28 and 29 are provided in the substrate support 3 through which the ignited plasma front 21 strikes. The substrate support 3 is mounted on the loops 30, 31.
FIGS. 4a to 4e show different permanent magnet arrangements which are suitable for the magnet system 11. The sketches in the upper part of the figure are profiles while those in the lower part are plan views.
In FIG. 4a is shown a U-shaped permanent magnet 32 which has two legs joined together by a yoke 33. The area of cyclotron resonance is indicated at 21. The broken lines 36 and 37 represent magnetic lines of force on which no cyclotron resonance takes place. The legs 34 and 35 are bar magnets each with a north and south pole, the position of north and south pole in leg 34 being the opposite of that of leg 35. The magnetic field of the arrangement in FIG. 4a exercises a leveling effect on the thickness of the deposited layer in the lengthwise direction, which appears to be attributable to a cooperative drifting of the electrons, such as is known in the magnetron art. The E×B movement known in the sputtering magnetron is lacking because there is no constant E field perpendicular to the B field. However, a drift movement lengthwise of the magnetic field arrangement can be assumed, which is due to the great decrease of the B field above and below the cyclotron resonance surface. The resulting force is then F˜∇B×B. This resultant force furthermore brings it about that the plasma burns well in front of a substrate support which covers the magnetic field-producing apparatus only if the substrate support has slots in the area of the face of the magnet system, as represented in FIG. 3.
Another permanent magnet arrangement is shown in FIG. 4b. Here three bar magnets 38, 39 and 40 with alternating north and south poles are arranged side by side on a common yoke 41. In this manner a linearization of the cyclotron resonance zone is obtained, because then two small resonance arcs 42, 43 are disposed side by side. As it can be seen from the lower part of the sketch, the two outer bar magnets 38 and 40 are joined together by legs 44 and 45. The arrangement in FIG. 4b is also called a "race-track" arrangement.
FIG. 4c shows a single bar magnet 46 which forms two cyclotron resonance regions 47 and 48. From the lower sketch it can be seen that the north pole and south pole are at a relatively short distance from one another compared with the total length of the north pole and south pole. In general, a very large-area configuration of the 0.088 Tesla region will be desired. This, however, requires a magnet mass that is greater than that required for a conventional magnetron magnetic field by a factor of about 3.
FIG. 4d shows a so-called "matrix" arrangement of magnets, in which a total of nine permanent magnets 48-56 are arranged at equal distances from one another and with alternating polarity.
In FIG. 4e there is shown a permanent magnet system similar to the one in FIG. 4a. In this case, however, the permanent magnets 57 and 58 joined by the yoke 59 form a cyclotron resonance region 60, 61, around their own north pole-south pole alignment. This is a magnet system equipped with simple components, such as is used for sputtering magnetrons, in which the electron-cyclotron resonance takes place around the individual magnets.
In addition to its function of providing for a resonance, the magnetic fields serve the function of a magnetic trap, in a manner similar to the normal magnetic circuit; i.e., the plasma is concentrated in the region of the magnetic field.
FIG. 5 shows an apparatus in which a waveguide 16 is divided into two waveguides 62 and 63. Each of the latter waveguides 62 and 63 terminates in its own horn radiator 64, 65. A plurality of horn radiators can be created in like manner, whose combined wave field is substantially more uniform than that of a single horn radiator.
FIG. 6 represents schematically the manner in which spoolable materials can be coated with the apparatus according to the invention. In this case the representation of the injection of the microwave has been omitted. All that is shown is the magnet system 11 as well as a portion of a roller guide for the spoolable material 67 which is guided over rollers 68 and 69. The roller 66 in this case extends over the circumference of the indicated circle 70.
FIG. 7 shows schematically the arrangement of the microwave transmitter system which is used in the invention. It has a microwave generator 71 which is connected by a circulator 72 and a three-rod tuner 73 to a horn radiator 74. A device 75 for measuring the reflected power is connected to the circulator. This device is symbolized by a diode. Between the three-rod tuner 73 and the horn radiator 74 there is connected an additional meter 76 by which the forward power is measured. This meter 76 is also represented simply by a diode.
The injection of the microwave power can be performed from a simple, unterminated hollow conductor, for in this case a certain part of the microwave power issues from one end.
Due to the abrupt transition, however, some reflection of the microwave output passes into the hollow conductor. An almost complete radiation can be achieved by gradual transition, as a uniform flaring of the hollow conductor towards a horn. In the present case, where a reflection of 5 to 10% of the radiated power is still acceptable, an approximation of the shape represented in FIGS. 1, 2 and 3 is entirely sufficient.
In FIGS. 8a and 8b additional shields 77, 78, 79, 80 and 81 are provided by which it can be brought about that ion-supported deposition can be performed (FIG. 8b) or that deposition is performed without simultaneous ion bombardment (FIG. 8a). Here the magnet system, as in the case of the magnet systems of the previous figures, is provided with a covering 82. If there are enough rotations of the electrons between the collisions in the range of the electron-cyclotron resonance frequency, the electrons can assume high kinetic energies. Since the magnetic field offers no resistance to their movement in the direction of the lines of force, in the embodiments represented in FIGS. 1 and 3, the area of the substrate in which the lines of force break through is exposed to a corresponding electron bombardment, which leads, due to the resultant negative charge, the so-called "self-bias," to a corresponding bombardment of this area by positive ions. This ion bombardment can be controlled by the shields.
The embodiments of the invention represented in the drawing can be varied in many ways. For example, the position of the plane of the microwave window 14 relative to the plane of the substrate is not limited to the parallelism represented in FIGS. 1 to 3. Instead, the described configuration of a multimode state in chamber 5 can be achieved by any desired position of the microwave window 14. What is important is only the relationship between the substrate surface to be treated and the region of electron-cyclotron resonance.
Neither do the magnetic pole faces need, as represented in FIGS. 4a, b, c, d and e, to lie in a single plane. Furthermore, a staggering in depth can be performed by situating all north pole faces in a first plane and all south pole faces in a different second plane. Also the distances between the north poles and south poles can be made variable.
It has proven especially advantageous to use the invention for the application of a protective coating of SiO x that is transparent in the range of visible light, x amounting to between 1 and 2. A gaseous hydrogen silicide, i.e. Sin H 2n+2 , is decomposed with the feeding in of oxygen or an oxygenous compound in a plasma discharge, and the SiO x that is formed is precipitated on a front-surface mirror forming a substrate.
Additionally, a gaseous monomer from the group of the silicon hydrocarbons can be introduced into the plasma discharge.
It has been found that, by the plasma polymerization in the microwave plasma, good protective coatings can be deposited at very high rates of deposit. In this manner it is possible, for example, in the manufacture of searchlight reflectors having an aluminum coating and a protective coating against corrosion, to apply both coatings in one machine, which in a first step applies the aluminum coating by sputtering, and in a second step deposits the protective SiO x coating by the above-mentioned plasma polymerization.
In connection with the deposit of hydrogen-containing silicon dioxide in the microwave plasma from silane (SiH 4 ) and laughing gas (N 2 O), quantitative measurements were performed in regard to the permeability of a protective coating obtained according to the invention in comparison to the permeability of conventional plasma-polymerized coatings.
Oxygen was used as the test gas. It was found that the SiO 2 coatings applied according to the invention had a permeability for oxygen that was smaller by a factor of 40 than conventionally made coatings of equal thickness.
With the invention it is possible to obtain dense coatings with good stoichiometry even at N 2 O:silane ratios <2, i.e., there is no need for the great N 2 O gas flow required in the known processes, which requires a great deal of pumping capacity, but in no way contributes to increasing the rate of deposit. The N 2 O flow rate which is needed in the invention is less than the previously known flow rates by a factor of about 10 to 50. Furthermore, the deposit rate of about 10 nm/s achieved with the invention is greater than the previously known deposit rates by a factor of at least 50.
EXAMPLE
An apparatus for coating in the microwave plasma is first evacuated to a remanent gas pressure of <1 ·10 -4 . Then silane gas (SiH 4 ) is admitted at such a rate of flow that a silane partial pressure of 2 ·10 -3 mbar is established. Then additional laughing gas (N 2 O) is admitted until a stationary total pressure of 6 ·10 -3 mbar is reached. Then microwave power is fed into the apparatus, through a window that is transparent to microwaves. The power density amounts in this case to about 3 W per cm 2 of window area. In a magnetic field which is situated within the apparatus a plasma is then produced.
A searchlight reflector fastened on a substrate carrier and freshly vapor-coated with aluminum is moved through the plasma zone at such a velocity that each point of the reflector surface spends 5 seconds in the plasma. This results in a coating deposited on the reflector in an average thickness of 40 nm, which corresponds to a rate of deposit of 8 nm/s. Examination of this coating by photoelectron spectroscopy shows a ratio of Si : 0 of about 1 : 1.18, i.e., good stoichiometry.
To test the protective action of the applied coating an 0.2% NaOH solution is applied and the time that elapses until the dissolution of the Al coating is measured. It is longer than three hours for the described coating.
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The invention relates to an apparatus for producing a plasma and treating substrates therein. The plasma produced by means of microwaves serves to coat a substrate which is situated in a chamber (5) having metal walls (6,7,12,13). The microwaves are repeatedly reflected at the metal walls (6,7,12,13), so that the chamber (5) has numerous microwave modes. By means of permanent magnets, which are placed either inside the chamber (5) or outside the chamber (5) in the vicinity of the substrate that is to be coated, it is possible to produce within this chamber (5) an electron-cyclotron resonance which permits a locally controlled ignition of the plasma.
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BACKGROUND OF THE INVENTIONS
[0001] 1. Field of the Inventions
[0002] The present inventions are related to fuel cell systems.
[0003] 2. Description of the Related Art
[0004] Fuel cells, which convert reactants (i.e. fuel and oxidant) into electricity and reaction products, are advantageous because they are not hampered by lengthy recharging cycles, as are rechargeable batteries, and are relatively small and lightweight. Nevertheless, the present inventors have determined that conventional fuel cells are susceptible to improvement. For example, ambient air is not available in many instances and oxidant (typically oxygen) must be stored in compressed form within the fuel cell system or host device. The present inventors have determined that because oxygen in the gas phase has relatively low density, large volumes of oxygen must be stored when the fuel cell is using relatively high energy density fuels such as hydrocarbons. The present inventors have also determined that the use of fuel cells which operate at a relatively high temperature (e.g. 200° C. and above) and/or produce relatively humid exhaust can present a variety of challenges. Extensive insulation is required to protect users and other devices from the heat, while the high levels of humidity can result in significant condensation as the exhaust cools. These issues are magnified in closed systems, including some military applications, where the exhaust from the fuel cell cannot be vented and heat cannot be detectable.
SUMMARY OF THE INVENTIONS
[0005] An apparatus in accordance with one of the present inventions includes a fuel cell and an oxygen supply operably connected to the fuel cell. The oxygen supply may, for example, include an inorganic oxygen containing salt that decomposes into oxygen and a non-volatile salt.
[0006] A method in accordance with one of the present inventions includes the steps of decomposing an inorganic oxygen containing salt into oxygen and a non-volatile salt and supplying the oxygen to a fuel cell.
[0007] An apparatus in accordance with one of the present inventions includes a fuel cell and means, operably connected to the fuel cell, for decomposing an inorganic oxygen containing salt into oxygen and a non-volatile salt.
[0008] An apparatus in accordance with one of the present inventions includes a power consuming device and a fuel cell system. The fuel cell system may include a fuel cell, a fuel supply, and an oxygen supply with an inorganic oxygen containing salt that decomposes into oxygen and a non-volatile salt.
[0009] An apparatus in accordance with one of the present inventions includes a fuel cell and a waste products storage device. The waste products storage device may include an absorbent material that endothermically reacts with byproducts from the fuel cell.
[0010] A method in accordance with one of the present inventions includes the steps of transferring fuel cell reaction byproducts to a waste products storage device and mixing the fuel cell reaction byproducts with an absorbent material that endothermically reacts with the byproducts.
[0011] An apparatus in accordance with one of the present inventions includes a fuel cell and means for receiving byproducts from the fuel cell, using the byproducts in an endothermic reaction, and storing all products of the endothermic reaction.
[0012] An apparatus in accordance with one of the present inventions includes a power consuming device and a fuel cell system. The fuel cell system may include a fuel cell and a waste products storage device, operably connected to the fuel cell, including an absorbent material that endothermically reacts with byproducts from the fuel cell.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Detailed description of embodiments of the inventions will be made with reference to the accompanying drawings.
[0014] FIG. 1 is a diagrammatic view of a fuel cell system in accordance with an embodiment of a present invention.
[0015] FIG. 2 is a section view of a fuel cell that may be employed in the system illustrated in FIG. 1 .
[0016] FIG. 3 is a section view of an oxidant supply in accordance with an embodiment of a present invention.
[0017] FIG. 4 is a section view taken along line 4 - 4 in FIG. 3 .
[0018] FIG. 5 is a diagrammatic view of a power consuming apparatus in accordance with an embodiment of a present invention.
[0019] FIG. 6 is a diagrammatic view of a fuel cell system in accordance with an embodiment of a present invention.
[0020] FIG. 7 is a diagrammatic view of a fuel cell system in accordance with an embodiment of a present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] The following is a detailed description of the best presently known modes of carrying out the inventions. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the inventions. It is noted that detailed discussions of fuel cell structures that are not pertinent to the present inventions have been omitted for the sake of simplicity. The present inventions are also applicable to a wide range of fuel cell technologies and fuel cell systems, including those presently being developed or yet to be developed. For example, although various exemplary fuel cell systems are described below with reference to solid oxide fuel cells (“SOFCs”), other types of fuel cells, such as molten carbonate fuel cells, are equally applicable to the present inventions. Also, although the exemplary fuel cells described below are multi-chamber fuel cells, the present inventions are also applicable to single chamber fuel cells.
[0022] As illustrated for example in FIGS. 1 and 2 , a fuel cell system 100 in accordance with one embodiment of a present invention includes one or more fuel cells 102 packaged in housing 104 . The exemplary fuel cell 102 , which is an SOFC, includes an anode 106 and a cathode 108 separated by an electrolyte 110 . Current collectors (not shown) are respectively associated with the anode 106 and cathode 108 . The anode 106 and cathode 108 , on opposing faces of the electrolyte 110 , are each composed of a thin catalyst layer and, optionally, a gas diffusion layer. A fuel supply 112 supplies fuel, e.g. hydrocarbon fuels such as methane (CH 4 ), ethane (C 2 H 6 ), propane (C 3 H 8 ) etc., to the anode 106 by way of a manifold (not shown) in the housing 104 and an oxidant supply 114 supplies oxidant, such as oxygen (O 2 ), to the cathode 108 by way of a manifold (not shown) in the housing. The fuel is electrochemically oxidized at the anode catalytic surface, reacting with O 2− ions that were produced by the reaction of O 2 with the cathode catalytic surface and diffused across the O 2− conducting electrolyte 110 . The reaction at the anode produces byproducts, i.e. water vapor (H 2 O) and carbon dioxide (CO 2 ) in the exemplary embodiment. In those instances where a plurality of fuel cells are arranged in a stack, the current collectors of the individual fuel cells may be connected to one another in series or parallel depending on the load.
[0023] The exemplary fuel cell system 100 is also provided with a waste products storage device 116 , which may be used to store byproducts from the fuel cell 102 , and a heat exchanger 118 , which may be used to heat the reactants before they reach the fuel cell 102 . In some instances, unused reactants may also be stored. A controller 120 may be provided to monitor and control the operations of the exemplary fuel cell system 100 . Alternatively, the operation of the fuel cell system may be controlled by the host (i.e. power consuming) device. The system components described above are located within a housing 122 , which is preferably insulated, and a pair of electrical contacts 124 a and 124 b are associated with the exterior of the housing.
[0024] The exemplary fuel cell system 100 is a “closed” system and, to that end, the fuel supply 112 , oxidant supply 114 and housing 122 are not configured to permit removal and replacement of the fuel and oxidant supplies. All of the reactants that will be consumed by the “closed” system are initially present in the system. The storage device 116 will also remain in the housing 122 and, to that end, all of the byproducts generated by the fuel cell reaction (as well as any unused reactants that pass through the fuel cell) will remain within the housing. Alternative fuel cell system configurations in accordance with the present inventions, which may be “open” to various degrees, are discussed below with reference to FIGS. 6 and 7 .
[0025] Referring more specifically to the manner in which reactants are stored in the exemplary fuel cell system 100 , and as noted above, the fuel and oxidant supplies 112 and 114 are located within the housing 122 . The respective configurations of the fuel and oxidant supplies 112 and 114 will depend on the manner in which the fuel and oxidant is stored. In the exemplary system 100 illustrated in FIGS. 1 and 2 , the fuel supply 112 is a pressurized fuel storage device, such as that illustrated in U.S. patent Pub. No. 2003/0136453 A1. The pressure forces the fuel through an anode inlet line 126 . A valve 128 may be provided so that the supply of fuel can be stopped when the fuel cell system is not operating and the quantity of fuel can be precisely metered, based on the load, when the system is operating. Anode-side byproducts and unused reactant (if any) are transferred to the waste products storage device 116 through an outlet line 130 .
[0026] Turning to FIGS. 3 and 4 , the exemplary oxidant supply 116 includes a housing 132 in which an oxygen producing material 134 is stored. The oxygen producing material in the exemplary implementation is an inorganic oxygen containing salt that will decompose into O 2 and a non-volatile salt when heated. One example of an inorganic oxygen containing salt is a metal chlorate, and preferably an alkali metal chlorate, such as potassium chlorate (KClO 3 ), sodium chlorate (NaClO 3 ) or lithium chlorate (LiClO 3 ). Other examples include metal perchlorates, such as potassium perchlorate (KClO 4 ) and sodium perchlorate (NaClO 4 ), and metal permanganates, such as potassium permanganate (KMnO 4 ). The inorganic oxygen containing salt may be stored in solid form such as, for example, a thick film on a porous medium that is capable of being heated and cooled in the manner described below.
[0027] As noted above, one example of an inorganic oxygen containing salt is a metal chlorate. Metal chlorates will decompose when heated to about 400° C. into a metal chloride and O 2 , e.g. 2KClO 3 →2KCl+3O 2 . Metal chlorates also have relatively high oxygen content, e.g. 1 g of KClO 3 has 0.39 g of O 2 . A solid metal chloride will remain within the housing 132 after the decomposition, and O 2 will be forced out of the oxidant supply 114 , and through a cathode inlet line 136 , due to the pressure buildup within the housing. A filter membrane 137 ( FIG. 3 ) that only allows the O 2 to pass may be positioned within the housing 132 adjacent to the inlet line 136 . Cathode-side byproducts and unused reactant (if any) are transferred to the waste products storage device 116 through an outlet line 138 ( FIG. 1 ).
[0028] There are a number of advantages associated with supplying O 2 in this manner. By way of example, but not limitation, supplying O 2 in this manner allows fuel cells to perform better in situations where ambient air is not available, such as underwater and high altitude applications and those instances where the fuel cell is carried in an airtight container or used in an inert atmosphere. Supplying O 2 in this manner also provides substantial volumetric savings, e.g. 1 cm 3 of KClO 3 produces 639 cm 3 of O 2 at 25° C. and 1 atmosphere.
[0029] The heat for the decomposition of the metal chlorate or other inorganic oxygen containing salt may be provided in a variety of ways, both at startup and after fuel cell operation has begun. In the exemplary implementation illustrated in FIGS. 3 and 4 , heat is provided at startup by a parasitic heater 140 , i.e. a heater which consumes energy stored in the fuel cell system 100 . The exemplary parasitic heater 140 , which may also be used to regulate the amount of heat that is supplied to the oxygen producing material 134 in the manner described below, is a resistive heater that includes a plurality of resistors 142 in a housing 144 . The heater 140 is powered by a battery 146 that is recharged by the fuel cell 102 during fuel cell operations. The battery 146 may also be used to power the controller 120 . The resistors 142 are carried on the exterior of the housing 132 and, accordingly, the housing 132 should be formed from material that is relatively high in thermal conductivity.
[0030] The parasitic heater 140 may, alternatively, be a fuel burning heater that burns fuel from the fuel supply 112 . Other types of heaters that may be used to provide heat for the decomposition reaction include, for example, microcatalytic combustors, ignition heaters and heat pipes.
[0031] Once the fuel cell reaction has started, heat for the decomposition of the inorganic oxygen containing salt is provided by a heater 148 ( FIG. 4 ) that uses the byproducts from the fuel cell anode and cathode chambers. The exemplary heater 148 is a catalytic combustor which includes a housing 150 that encloses an interior region 152 in which catalytic material (not shown) is located. Referring to FIG. 1 , the heater 148 receives some of the byproducts and unused reactants (if any) from the anode-side outlet line 130 , which are burned to produce heat, by way of an inlet line 154 . The heater 148 also receives some of the byproducts and unused reactants (if any) from the cathode-side outlet line 138 by way of an inlet line 155 . The output from the heater 148 is transferred to the waste products storage device 116 through an outlet line 156 .
[0032] The heater 148 may, alternatively, be a heat exchanger that draws heat from the fuel cell exhaust. The exhaust may be from the anode, the cathode or both. Other exemplary heaters include microcatalytic combustors, ignition heaters and heat pipes.
[0033] Regardless of the type of heater employed, the heater 148 may be configured in some embodiments of the inventions such that the amount of heat supplied to the oxygen producing material 134 (e.g. the inorganic oxygen containing salt) will be slightly less heat than the amount of heat required to cause substantial decomposition into non-volatile salt and O 2 . The additional heat will be supplied by the parasitic heater 140 as required based on the load on the fuel cell 102 . In other words, the amount of O 2 generated by the oxygen supply 114 may be controlled by controlling the amount of heat supplied to the oxygen supply by the parasitic heater 140 .
[0034] Turning to the manner in which the exemplary system 100 stores fuel cell reaction byproducts and suppresses heat, the heat from the fuel cell reaction may be used to drive endothermic reactions of the byproducts and materials that are stored in the waste products storage device 116 . More specifically, in the exemplary system where the byproducts are H 2 O and CO 2 , the waste products storage device 116 includes a reaction chamber 158 in which an absorbent material 160 is stored. As used herein, the phrase “absorbent material” means a material that efficiently absorbs H 2 O and CO 2 in endothermic fashion. Suitable materials include metals which have a strong tendency to oxidize (e.g. calcium (Ca), strontium (Sr), magnesium (Mg) and aluminum (Al)) and metal oxides (e.g. calcium oxide (CaO), strontium oxide (SrO), magnesium oxide (MgO) and aluminum oxide (Al 2 O 3 )). Exemplary endothermic reactions include H 2 O+CaO→Ca(OH) 2 ; CO 2 +CaO→CaCO 3 ; H 2 O+Ca→CaO+H 2 ; H 2 O+CO 2 2H + +HCO 3 − (aq.). The products of these reactions remain within the reaction chamber 158 in solid or liquid form.
[0035] The waste products storage device 116 should also be thermally connected to the heat exchanger 118 so that excess heat from the fuel cell 102 can be used to drive the endothermic reaction in the waste products storage device. This may be accomplished by positioning the heat exchanger 118 and waste product storage device 116 in physical contact with one another, or by thermally connecting them to one another with a heat pipe or other heat conduction pathway. Infrared radiation from the heat exchanger 118 may also be used to heat the contents of the waste products storage device 116 .
[0036] There are a variety of advantages associated with storing the byproducts in this manner. By way of example, but not limitation, fuel cell systems with the present waste products storage device do not produce the exhaust associated with conventional fuel cell systems. As such, they are especially useful in closed systems, including some military applications, where the exhaust from the fuel cell cannot be vented. They are also useful in electronic applications, where the condensation exhaust with high levels of humidity can produce significant condensation. The waste products storage arrangement also consumes much of the heat from the fuel cell reaction and, as a result, the extensive insulation associated with conventional fuel cells in not required.
[0037] The waste products storage device 116 may also be used to return H 2 and any unused fuel to the anode inlet line 126 , thereby increasing the overall efficiency of the system. The H 2 and unused fuel pass through a tube 162 to the valve 128 . In the exemplary implementation, a selective membrane 163 (such as a palladium-based membrane) is positioned within the waste product storage device 116 at the inlet to the tube 162 . The selective membrane 163 allows only the H 2 and unused fuel to enter the tube 162 .
[0038] There are also many instances where it is desirable to heat the reactants before they reach the fuel cell 102 and, to that end, the exemplary system 100 includes the aforementioned heat exchanger 118 ( FIG. 1 ). Reactant pre-heating prevents the reactants, which may be at a temperature that is less than the operating temperature of the fuel cell 102 , from cooling the fuel cell. Suitable heat exchangers include microchannel heat exchangers, cross flow microchannel heat exchangers, “Swiss roll” heat exchangers, and metal foam heat exchangers. The heat exchanger 118 receives heated byproducts from the anode and cathode by way of the inlet lines 154 and 155 . After traveling through the heat exchanger 118 , the byproducts are transported to the waste products storage device 116 by way of the outlet line 156 .
[0039] Although the materials, dimensions, and configuration of the fuel cells in the exemplary fuel cell systems will depend upon the type of fuel cell (e.g. SOFC, molten carbonate fuel cell, etc.) and intended application, and although the present inventions are not limited to any particular materials, dimensions, configuration or type, exemplary fuel cells are described below. The exemplary fuels cells are relatively small (e.g. about 10 μm×10 μm to about 10 cm×10 cm) SOFCs. The exemplary fuel cells are also preferably “thin” (i.e. between about 0.3 to 2000 μm thick). The anodes are preferably a porous, ceramic and metal composite (also referred to as “cermet”) film that is about 0.1 to 500 μm thick. Suitable ceramics include samaria-doped ceria (“SDC”), gadolinia-doped ceria (“GDC”) and yttria stabilized zirconia (“YSZ”) and suitable metals include nickel and copper. The cathodes are preferably a porous ceramic film that is about 0.1 to 500 μm thick. Suitable ceramic materials include samarium strontium cobalt oxide (“SSCO”), lanthanum strontium manganate, and bismuth copper substituted vanadate. The electrolytes are preferably a non-porous ceramic film, such as SDC, GDC or YSZ, that is about 0.1 to 1000 μm thick, depending on the material.
[0040] The exemplary fuel cell system 100 may be incorporated into a wide variety of power consuming apparatus. Examples of power consuming apparatus include, but are not limited to, information processing devices such as notebook personal computers (“PCs”), handheld PCs, laptop PCs, and personal digital assistants (“PDAs”), communication devices such as mobile telephones, wireless e-mail appliances and electronic books, video games and other toys, and audio and video devices such as compact disk players and video cameras. Other electronic devices include portable test systems, portable projectors, and portable televisions such as portable flat panel televisions. The exemplary fuel cell assembly 100 may also be used in military, high altitude and undersea applications such as, for example, communication devices, thermal imaging devices, night vision device surveillance devices, chemical detection devices, search and rescue apparatus, and undersea mines.
[0041] Referring to FIG. 5 , an exemplary apparatus 200 includes a fuel cell system 100 and a power consuming device 202 that is powered by the fuel cell system 100 . The exemplary power consuming device refers to any or all devices within the particular apparatus than consume electrical power. The fuel cell system 100 may be removably inserted into the exemplary apparatus 200 and, to that end, the exemplary apparatus includes a pair of electrical contacts 204 a and 204 b that will mate with the fuel cell system electrical contacts 124 a and 124 b.
[0042] Another exemplary fuel cell system, which is generally represented by reference numeral 100 a in FIG. 6 , is configured for use in those instances where ambient air is available as an oxidant source. The exemplary fuel cell system 100 a is substantially similar to the fuel cell system 100 illustrated in FIG. 1 and similar elements are represented by similar reference numerals. The fuel cell system 100 a suppresses heat and does not emit byproducts, for example, through the use of endothermic reactions of the byproducts and materials that are stored in the waste products storage device 116 . Here, however, the oxidant supply 114 a is simply a vent or a vent and fan arrangement that draws ambient air and the heaters 140 and 148 are not required. The exemplary fuel cell system 100 a is especially useful in those instances where ambient air with a suitable amount of O 2 is available, and the suppression of heat and/or humid exhaust is important. Consumer electronic devices are examples of devices that may be powered by the exemplary fuel cell system 100 a.
[0043] Another exemplary fuel cell system, which is generally represented by reference numeral 100 b in FIG. 7 , is configured for use in those instances where ambient air is not available as an oxidant source, but the emission heat and/or humid exhaust is acceptable, such as various high altitude and underwater applications. The exemplary fuel cell system 100 b is substantially similar to the fuel cell system 100 illustrated in FIG. 1 and similar elements are represented by similar reference numerals. The fuel cell system 100 b includes, for example, an oxidant supply 114 which produces O 2 by decomposing an oxygen producing material 134 , such as an inorganic oxygen containing salt. Here, however, the waste products storage device 116 is replaced by a vent 164 that simply vents the byproducts out of the housing 122 . In those instances where the fuel cell system 100 b is located within a host device, the host device will typically have a corresponding vent to transfer exhaust from the vent 164 out of the host device. A fuel recirculation system 166 , which returns H 2 and unused fuel to the anode inlet line 126 , thereby increasing the overall efficiency of the system, may also be provided.
[0044] It should be noted here that the exemplary fuel cell systems described above with reference to FIGS. 1-7 may also be configured such that the fuel supply 112 , oxidant supply 114 and/or waste products storage device 116 may be removed and replaced. Such an arrangement allows the fuel cell systems to be quickly and easily recharged. For example, the fuel supply 112 , oxidant supply 114 and/or waste products storage device 116 may be in the form of cartridges that have connectors which are configured to mate with corresponding connectors within the housing 122 . With respect to the oxidant supply 114 , the heaters 140 and 148 may be a permanent part of the fuel cell system, or part of the replaceable cartridge (with corresponding electrical and fluidic connectors added thereto).
[0045] Although the present inventions have been described in terms of the preferred embodiments above, numerous modifications and/or additions to the above-described preferred embodiments would be readily apparent to one skilled in the art. It is intended that the scope of the present inventions extend to all such modifications and/or additions.
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A fuel cell systems and methods involving decomposing an inorganic oxygen containing salt that decomposes into oxygen and a non-volatile salt and/or mixing fuel cell reaction byproducts with an absorbent material that endothermically reacts with the fuel cell reaction byproducts.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority of U.S. provisional patent application No. 60/692,798, filed Jun. 21, 2005, incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to wireless computer networks; in particular, the present invention relates to power saving operations in an ad hoc wireless computer network.
[0004] 2. Discussion of the Related Art
[0005] A wireless network allows a mobile user to maintain network access despite the mobile user's changes in location continuously or from time to time. By necessity, a mobile device operates from battery power and battery power is a scarce resource. Recently, improvements in battery lifetime for a mobile device have not kept up with improvements in computing power and communication capability. Hence, power efficiency is an important design parameter for a wireless computer network.
[0006] As compared to power management in an infrastructure network, power management in the link layer of an ad hoc wireless network (e.g., an ad hoc wireless network using the independent basic service set or “IBSS” under 802.11b) is not well understood and is not efficient. For example, in a wireless local area network (WLAN), the access point (“AP”) has global knowledge of the power-saving states of all stations (“STAs”) associated with it. In such a network, all communication with the mobile nodes go through the AP, so that the AP may buffer data packets designating STAs in a power-saving (“PS”) mode. During pre-specified time intervals, the AP notifies these STAs to retrieve the buffered packets. In contrast, however, in an ad hoc wireless network, there is no entity in IBSS similar to AP that has global knowledge of power-saving states of all nodes. Instead, each STA stores packets locally and communicates individually with its peers to schedule packet delivery.
[0007] Due to the distributed nature of IBSS, many power-saving issues exist in IBSS under 802.11.
[0008] In WLANs operating under 802.11, the distributed coordination function (“DCF”) uses a Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol to determine—in a distributed manner—when a station operating within the wireless network is permitted to transmit and receive frames. Under CSMA/CA, prior to transmission, an STA senses the medium to determine if it is “busy” (i.e., if another STA is transmitting). If the medium is not busy, the STA may transmit. CSMA/CA requires a minimum specified separation in time, called the “interframe space” (IFS), between contiguous frame sequences. The transmitter waits the medium to become idle for at least IFS before transmitting. The value of IFS varies according to the priority of the transmitted frames. Examples of IFS values include: short IFS (SIFS), point IFS (PIFS) and distributed IFS (DIFS).
[0009] SIFS is the shortest interframe space and is used when a group of STAs have seized the medium for the duration of the frame exchange sequence to be performed. SIFS ensures completion of the frame exchange sequence before other STAs can access the medium, as the other STAs are required to wait for the medium to become idle for a time period longer than SIFS before attempting to transmit into the medium. Acknowledgment (ACK) frames, for example, use SIFS.
[0010] PIFS is used by STAs operating under the point coordination function (PCF) to gain priority access to the medium at the start of a contention-free period. PIFS is longer than SIFS, but shorter than DIFS.
[0011] DIFS is used by stations operating under the DCF to transmit data frames and management frames (e.g., probe request and probe responses).
[0012] Under DCF, if the medium is found busy, an STA defers transmission until after the current transmission completes. After a deferral, or prior to attempting to transmit again immediately after a successful transmission, a station selects a random “back-off” interval during which it does not transmit. A back-off interval counter keeps track of the interval.
[0013] Some example formats of control packets are provided in FIGS. 1 (“probe request frame”), 3 (“probe response frame”), and 4 (“acknowledge (ACK) frame”). A control packet has a format (i.e., “management frame”) generically shown in FIG. 5 . As shown in FIG. 5 , the format includes a medium access control (MAC) header, a frame body and a frame check sequence (FCS). The FCS allows a determination on the integrity of a transmitted frame. In a 802.11 WLAN, an STA uses the destination address (DA) field in the MAC header of a packet to make receive decisions regarding the packet. For example, the DA field may contain a group address (e.g., a broadcast address) and, if the frame is not a beacon frame, the basic service set identifier (BSSID) must be validated (i.e., the BSSID field of the frame is the same BSSID of the recipient). (The BSSID field can be a broadcast BSSID in a probe request frame.) As another example, an STA, including an access point, may respond with an ACK frame within an SIFS deferral upon receiving a data frame or a management frame that does not specify a group address in the DA field. An ACK frames is not be transmitted for a packet specifying a group address in the DA field.
[0014] The state of the medium is determined from the physical and virtual carrier-sense functions. The physical layer provides a physical carrier-sense mechanism based on energy detection in the wireless medium. The MAC layer provides a virtual carrier-sense mechanism, referred to as the network allocation vector (NAV). The NAV predicts future traffic in the medium based on duration information that is announced in the frames prior to the actual exchange of data. With a few exceptions, such duration information is found in the MAC header.
[0015] A probe request frame is sent by an STA scanning an area for an existing network. A probe request frame invites the APs in the area to respond with probe response frames. As shown in FIG. 1 , a probe request frame includes a service set identifier (SSID) field and the data rates supported by the STA. An AP receiving a probe request frame determines whether to invite the STA to join the network. As shown in FIG. 2 , type bits (B 2 , B 3 ) and subtype bits (B 4 -B 7 ) of the frame control field identify both the frame type (e.g., “management”) and the subtype (e.g., “probe request”). Table 1 shows the various possible values of the type and subtype bits.
TABLE 1 Example of valid type and subtype combinations Subtype Type Value Type value B3 B2 description B7 B6 B5 B4 Subtype description 00 Management 0100 Probe request 00 Management 0101 Probe response 00 Management 1000 Beacon 00 Management 1001 ATIM 00 Management 1101 Action 00 Management 1110-1111 Reserved 01 Control 1101 Acknowledgement (ACK)
[0016] To respond to a probe request frame, an AP sends a probe response frame ( FIG. 3 ) to the scanning STA to inform the availability and the characteristics of the networks. Other frames include, for example, an ACK frame which acknowledges a received data frame, or a beacon frame (which announces the existence of a network).
[0017] Sending out beacon frames is an important part of many network maintenance tasks. Beacon frames are typically transmitted at regular intervals to allow mobile STAs to find, identify and match parameters of a network they may join. In a beacon frame, the frame body includes the following fields: (a) timestamp, (b) beacon interval, (c) capability, (d) SSID, (e) IBSS parameter set, and (f) traffic indication map (TIM). The information field within the IBSS parameter field contains an ATIM Window parameter. The IBSS parameter set format is shown in FIG. 14 .
[0018] In an infrastructure network, APs are responsible for transmitting Beacon frames. The service area of an AP is defined by the reach of its beacon frames. Timing for the BSS is determined by the beacon interval specified in a beacon frame. The time interval between successive transmissions of beacon frames is called the “target beacon transition time” or TBTT.
[0019] In an IBSS network, beacon frames are generated in a distributed manner. The beacon interval is included in both beacon frames and probe response frames. The STAs adopt the beacon interval at the time each STA join the ad hoc network. In an IBSS network, all members participate in beacon generation. Each STA maintains a timing synchronization function (TSF) timer for beacon interval timing. As an IBSS network does not have access points, when an STA has buffered frames for a receiver that is in a low-power mode, the STA sends an announcement traffic indication message (ATIM) frame during the ATIM window to notify the recipient that it has buffered data for the recipient. The ATIM frame has a null frame body.
[0020] FIG. 15 shows the process of beacon frame generation in an IBSS. At each TBTT, each station (a) waits for the packet currently transmitting in the channel to complete, (b) suspends the back-off timer for any pending non-beacon or non-ATIM transmission, and (c) calculates a random delay that is uniformly distributed in the range between zero and 2*CW min *TU, where CW min is the size of the minimum contention window and TU is the timing unit. The STA then sets a timer using this random delay and wait for this timer to expire. If a beacon frame arrives before the random delay timer expires, the wait is canceled, and the backoff timer is resumed. However, if the random delay timer expires without the STA receiving a beacon frame, the STA sends out a beacon frame. ATIM messages are transmitted following the beacon frame from source stations to destination stations using the same distributed coordination function (DCF) algorithm as ordinary data packets. The length of the ATIM window is fixed and always starts from the theoretical TBTT time, whether or not there is packet transmission during the beacon interval.
[0021] The timestamp field in the beacon frame represents the value in the TSF timer at the frame's source. A station joining an IBSS network initializes its TSF timer to 0 and refrains from transmitting a beacon frame or a probe response frame until after it receives a beacon frame or a probe response frame from another member of the IBSS with a matching SSID to ensure proper synchronization within the IBSS network.
[0022] In an IBSS network, an STA may be in an “awake” state, in which the STA is fully powered, or in a “doze” state, in which the STA consumes little power and is unable to transmit or receive. The term “power management” for an STA refers to the manner in which an STA transits between awake and doze states.
[0023] In an infrastructure network, an STA changing its power management mode to a doze or PS state informs the AP using the power management bits within the frame control field of the transmitted frames. Thereafter, the AP does not arbitrarily transmit MAC service data units (MSDUs) to the STA. The MSDUs are buffered and transmitted at designated times. The STAs associated with an AP that has buffered MSDUs for the STAs are identified in a TIM that is included in all beacon frames generated by the AP. By interpreting the TIM, an STA is made aware that an MSDU is buffered for it. An STA operating in PS modes periodically listens for beacon frames, according to its listen interval and receive delivery traffic indication message (DTIM) parameters. Upon learning that an MSDU is currently buffered in the AP, the STA transmits a short PS-poll frame to the AP, which responds with the corresponding buffered MSDU immediately, or acknowledges the PS-Poll and responds with the corresponding MSDU at a later time. If an STA in its BSS is in PS mode, the AP buffers all broadcast and multicast MSDUs and delivers them to the STA immediately following the next beacon frame containing a DTIM transmission.
[0024] FIG. 16 shows the basic operations of power management in an IBSS. As shown in FIG. 16 , after each TBTT, an ATIM window is defined. During the ATIM window, STAs operating in PS mode are awake to listen to beacon frames or ATIM frames. To transmit an MSDU to a recipient STA in a PS mode, the transmitting STA first transmits an ATIM frame during the ATIM window. ATIM transmissions from different STAs are randomized using the common DCF backoff procedure. Directed ATIMs are acknowledged. If a ACK frame is not received in response to a directed ATIM, the transmitting STA executes the back-off procedure to attempt a retransmission. Multicast ATIMs are not acknowledged. After the ATIM interval, the acknowledged MSDUs and the announced broadcast/multicast MSDUs are transmitted to STAs in the PS mode, using normal DCF access procedures. If an STA is unable to transmit a buffered MSDU during the beacon interval in which the MSDU is announced, the STA retains the buffered MSDU and announces it again in an ATIM during the next ATIM window. After all buffered MSDUs are transmitted, MSDUs are transmitted unannounced to STAs that are in the awake state.
[0025] An STA operating in PS mode enters the awake state prior to each TBTT. If the STA receives an ATIM management frame directed to it, or a multicast ATIM management frame during the ATIM Window, the STA remains in the awake state until the end of the next ATIM window. An STA that has transmitted a beacon frame or an ATIM management frame will remain in the awake state until the end of the next ATIM window, regardless of whether or not an acknowledgement is received for the ATIM. If the STA has not transmitted an ATIM and does not receive either an ATIM management frame directed to it, or a multicast ATIM management frame during the ATIM window, the STA may return to the Doze state following the end of the current ATIM window.
[0026] Beacon generation and power management are related activities. Beacon frames are transmitted during the awake periods of STAs operating in PS mode, such that all STAs may process the beacon frames. Furthermore, the source of a beacon frame does not enter the PS state until the end of the next active period, so as to ensure that at least one STA is awake to respond to probe request frames from new STAs scanning for a network.
[0027] Thus, the current standard requires that an STA transmitting a beacon frame in an IBSS network to remain awake until the end of the next ATIM window to ensure that any probe request sent by an STA scanning for a network is answered. The STA is kept awake regardless of whether or not the STA has packets to send or receive. Significant power is therefore dissipated by the STA. By keeping STAs sending ATIM/ACK awaken within the entire beacon interval, the standard enables an STA to derive the power management states of other STAs even without direct ATIM/ACK exchanges. For example, upon receiving a multicast/broadcast frame, the receiver infers that the sender is awake throughout the entire beacon interval. A receiver of a unicast ATIM frame can make the same inference, even though, in the event that the ACK frame is lost, the sender may not infer the power management state of the receiver. With this extra information, an STA can send frames to those STAs that it infers to be in an awake mode.
[0028] There is, therefore, a need for improved power-savings in active stations by allowing the active stations to enter a doze mode promptly after finishing packet transmission and reception, while maintaining the ability by STAs to make inference of the power management states of other STAs and ensuring that an STA entering a doze mode does not impair ommunications between the STA and its neighbors.
SUMMARY
[0029] The present invention provides methods for increasing power saving in an STA that sends or receives frames in an ad hoc wireless network (e.g., IBSS), while allowing the STA to enter a power-saving mode quickly upon completion of scheduled tasks. At the same time, a method of the present invention allows two STAs to infer each other's power management mode without requiring an ATIM/ACK exchange between the STAs within an ATIM window. Consequently, according to the present invention, an STA may enter a power-saving mode promptly without impairing the STA's ability to receive packets.
[0030] According to one embodiment of the present invention, a “more data” field is used between STAs to exchange information regarding future data transmissions. According to various embodiments of the present invention, STAs with different computational abilities provide information under different time constraints. STAs may enter power-saving modes that send multicast/broadcast frames or use promiscuous mode within an ATIM window.
[0031] The present invention is better understood upon consideration of the detailed description below in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 shows the format for a probe request frame.
[0033] FIG. 2 shows data fields within a frame control field of a frame.
[0034] FIG. 3 shows the format for a probe response frame.
[0035] FIG. 4 shows the format for an acknowledge (ACK) frame.
[0036] FIG. 5 shows the generic format for a management frame.
[0037] FIG. 6 illustrates the operation of a receiving STA, in accordance with one embodiment of the present invention.
[0038] FIG. 7 shows one method by which the receiver STA may avoid waiting for a sender STA who did not receive an ACK frame to an ATIM frame, in accordance with one embodiment of the present invention.
[0039] FIG. 8 illustrates protocol transactions by which a receiver STA notifies a sender STA that it has data to send, in accordance with one embodiment of the present invention.
[0040] FIG. 9 shows another method for a receiver STA to send a notification message to a sender STA, in accordance with one embodiment of the present invention.
[0041] FIG. 10 shows the sender STA's process to determine when to enter a doze mode, in response to the receiver's process described above in conjunction with FIG. 9 .
[0042] FIG. 11 is a flow chart that illustrates how a multicast sender STA may determine the ACK frame received in response to a multicast notification frame.
[0043] FIG. 12 shows one method for a multicast or broadcast sender STA to enter a doze mode, using an ACK frame collision detection technique, in accordance with one embodiment of the present invention.
[0044] FIG. 13 shows a process by which a multicast or broadcast sender STA enters a doze mode, using a timer to determine if there is data to be received from other STAs, in accordance with one embodiment of the present invention.
[0045] FIG. 14 shows fields in the IBSS parameter set of a beacon frame.
[0046] FIG. 15 shows the process of beacon frame generation in an IBSS.
[0047] FIG. 16 shows the basic operations of power management in an IBSS.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] The present invention provides algorithms that optimize power-savings for active STAs (i.e., those wireless STAs sending or receiving messages) in an ad hoc wireless network.
[0049] In one embodiment of the present invention, STAs of an ad hoc wireless network send or receive only unicast ATIM messages within the ATIM window and do not operate in a promiscuous mode (i.e., in conformance with the practice under 802.11 standards). Under 802.11, based on an exchange of an ATIM frame and an ACK frame, the sender and receiver STAs may infer different internal states about each other:
TABLE 2 Sender and Receiver Internal States Case # Sender Receiver Implication 1 Sends an ATIM Receives an ATIM The Sender and the Receiver frame correctly and frame correctly and believe that they are in the receives an ACK sends an ACK frame same power state, and frame correctly correctly therefore consider each other as peers. 2 Sends an ATIM Receives an ATIM The Receiver treats the Sender frame correctly, but frame correctly and as its peer, but the Sender does fails to receive the Sends the not treat the Receiver as its corresponding ACK corresponding ACK peer. frame, frame correctly 3 Sends an ATIM Fails to receiver an Neither the Receiver nor the frame correctly, but ATIM frame, and thus Sender treats the other as its fails to receive the does not send a peer. corresponding ACK corresponding ACK frame. frame.
[0050] An STA sends a data frame to a recipient STA upon the expiration of an ATIM window only if an ATIM frame from the STA is correctly acknowledged by the receiver STA within the ATIM window. If the sender STA of the data frame has one or more additional data frames to be sent to the receiver STA after the current data frame, the sender STA sets the “more data” field of the current data frame to ‘1’. Otherwise, the sender sets the “more data” field to ‘0’, thereby informing the receiver that the current data frame is the final frame from the sender STA. Within a beacon interval, if a STA only receives data frames, upon receiving the final data frame from each sender STA (i.e., after receiving from each expected sender a data frame with the “More Data” field set to ‘0’), the STA may enter a power-saving state or doze mode. This scheme works properly for cases 1 and 3 of Table 2 above. However, under case 2 of Table 2, the sender—not having received an ACK frame to the ATIM frame from the receiver STA during the ATIM window—would not send a data frame to the receiver STA, while the receiver STA expects to receive the data frame. As a result, the receiver STA waits in vain for the expected data frame and does not enter the doze mode.
[0051] In this embodiment, the sender STA uses information other than the ATIM/ACK exchange to infer that the receiver STA is in an awake state or active mode, and sends out the data frame to the receiver STA. Some examples of information that allows the sender STA to infer the receiver STA's power saving mode include: a) the receiver STA is the sender of some multicast or broadcast frames, or b) the receiver STA is also expected to send a data frame to the sender STA.
[0052] Alternatively, in addition to sending data frames to STAs from which acknowledgement to ATIM frames were correctly received, the sender STA may send data frames to STAs that did not correctly acknowledge ATIM frames (i.e., both cases 2 and 3 of Table 2). Under this scheme, the receiver STA acknowledges the data frame when the data frame is correctly received. Otherwise—i.e., if the data frame is not correctly received at the receiver STA, or if the receiver STA is in a doze mode when the data frame is sent—after the sender has waited for a time-out period and not receiving a corresponding ACK frame to the data frame, the sender STA concludes that the receiver STA is in a power-saving state and removes the receiver STA from its peer list. Alternatively, if the data to be sent is lengthy, the sender STA may use the Request to send/Clear to Send (RTS/CTS) mechanism first to establish that the receiver STA is awake before sending the data frame.
[0053] FIG. 6 illustrates the operation of a receiving STA. As shown in FIG. 6 , an STA maintains a peer list by recording sender STAs from which the STA receives an ATIM frame during the ATIM window (steps 601 , 602 ). As data frames are received (step 604 ), a sender STA is removed from the peer list when a data frame is received from the sender STA with the “more data” field set to ‘0’ (steps 605 , 606 ). As described above, the sender STA may send a data frame corresponding to a previous ATIM frame that it did not receive an acknowledgement. Therefore, when the receiver STA receives a data frame from a sender STA not on its peer list (step 609 ), representing a possible missed ATIM frame, the receiver STA adds the sender to the peer list (step 610 ). Normally, when the peer list becomes empty, the receiver STA enters a doze mode (step 608 ). Although not required, before entering the doze mode, however, the receiver STA may send out a multicast null data frame to inform its neighbors about the impending power management transition (step 607 ).
[0054] Still alternatively, a receiver STA may send a unicast null data frame to a sender STA with the power management field in the header set to ‘1’, after observing that the channel has been idle over a period of time, even though the receiver STA expects a data frame from the sender STA by reason of the previous ATIM frame. FIG. 7 shows one method by which the receiver STA may avoid waiting for a sender STA which did not receive an ACK frame to an ATIM frame. As shown in FIG. 7 , the receiver STA maintains a timer for each sender STA on its peer list (step 701 ). As a data frame is received from a sender STA, the receiver STA resets the timer for that sender STA (step 702 ). When a timer for a sender STA expires after a predetermined time period (i.e., the timer “times out”, step 703 ), the receiver STA sends out the unicast null data frame (step 703 ). When the ACK frame corresponding to the null data frame arrives, the timer is reset (step 706 ). If the null data frame is not acknowledged after a predetermined time interval (step 705 ), the receiver STA may resend the null data frame after a back-off interval for up to a predetermined retransmission limit (stepa 707 , 708 ). When the predetermined retransmission limit is reached (step 709 ), the receiver STA regards the sender STA as being in a doze mode and accordingly removes the sender from its peer list (step 710 ).
[0055] As described above, a sender STA may enter a doze mode after sending all outstanding data frames to its receivers, and by setting the “more data” field to ‘0’ in its final data frame to each receiver during the current beacon interval, thereby notifying the end of its transmission to the receiver. However, this description has not taken in to consideration that a sender STA may itself be a receiver. For example, under the current 802.11 standard, an STA may transmit a data frame without announcement to another STA that is known to be in the awake state for the current beacon interval (e.g., from transmitting an appropriate ATIM management frame). Hence, even though a sender STA has not received an ATIM frame from one of its receiver STAs, the receiver STA may still send data frames to the sender STA. So ideally, after finishing sending out data frames, a sender STA should ascertain that there are not data frames to be sent from its receivers before entering a doze state. This embodiment provides, as examples, three methods for a sender STA to ascertain incoming data frames.
[0056] Upon receiving the final data frame from a sender STA with the “more data” field set to ‘0’ and when a receiver STA has data for the sender STA, a receiver STA sends back an ACK frame in which the receiver STA sets the “more data” field to ‘1’. Otherwise, the receiver STA sets the “more data” field of the ACK frame to ‘0’. The sender STA thereby learns the state of its receivers. When no data is expected from any of its receivers, the sender STA may enter a doze mode. Under this arrangement, the receiver STA sends out an ACK frame within the SIFS time after receiving a data frame from a sender STA. One drawback of this method is that, in many implementations, the receiver STA may not have enough computation capabilities to be able to determine whether or not it has data to send to the sender and accordingly correctly sets the “more data” field.
[0057] Alternatively, to allow more time to finish interval processing and to set up the “more data” field correctly, the receiver STA may send out the ACK frame after PIFS time. (PIFS time is the sum of SIFS and a slot time.) Because all other stations wait for at least DIFS time after the data frame is completed to access the channel, the receiver STA may still send out the ACK frame without risking collision, and thus this method extends the processing time by one slot time. Upon receiving this delayed ACK frame, if a sender STA has already timed out (i.e., assumed that the data frame did not properly reach the receiver) and has entered a back-off procedure to resend the data frame, the sender STA considers the previous data frame successfully transmitted and cancels the back-off procedure.
[0058] Still alternatively, the receiver STA sends the ACK frame within the conventional response time (i.e., within an SIFS time). However, if the receiver STA has outgoing data to any sender STA, the receiver STA sets the “more data” field to ‘1’ to indicate that the receiver STA is sending one or more data frames within the beacon interval. Otherwise, the “more data” field is set to ‘0’. In this manner, the receiver STA notifies all sender STAs its awake state globally. FIG. 9 shows one instance in which such a method for a receiver to send a notification message to a sender. As shown in FIG. 9 , a receiver maintains a list of active peers (step 901 ). When a message is received from a new sender STA, the new sender STA is added to the list, and when a peer notifies that it is entering a doze mode, the peer is removed from the list (step 902 ). If the receiver STA has any data to send to any STA in the peer list, the receiver STA sets the “more data” field to ‘1’ in the control and data frames it sends out (step 904 ). Otherwise, the receiver STA sets the “more data” field in outbound control or data messages to ‘0’ (step 905 ). When receiving a data frame (step 906 ), if the “more data” field is not set to ‘0’ (step 907 ), the receiver STA does not take any power-saving action, as it expects one or more additional data frames from the sender STA. However, if the data frame received has the “more data” field set to ‘0’, the receiver STA sends an ACK frame after SIFS time with the “more data” field set according to rules mentioned above (step 908 ). As this processing does not involve looking up the data to be sent to a particular sender STA, this information may be pre-processed, so that the value for the “more data” field may be established within the SIFS time constraint.
[0059] At the same time, the receiver STA may use the resources to prepare sender-specific actions. If the receiver STA has no data for a specific sender STA after transmissions from the specific sender STA is completed, the receiver STA can send a unicast null data frame to the sender STA after SIFS time or using distributed coordination function (DCF) procedure (step 912 ). The “more data” field of this null data field is set to ‘0’ to indicate that no further transmission is planned for the specific sender (step 912 ). Note that, if there is data for any sender STA, the “more data” field in the previous ACK frame was set to ‘1’. For this specific sender STA, the receiver STA sends one or more data frames (step 910 ) and, at the final one of these data frames, set the “more data” field to ‘0’ (step 911 ). In this manner, the receiver STA prepares data frames to specific sender STAs it has data and uses the “more data” field in the data frame to communicate with the specific sender STAs.
[0060] The null data frame (step 912 ) may be sent out one or more ways. For example, the null data frame may immediate follow the ACK frame within SIFS time to avoid contention. The sender STA may send an ACK frame to acknowledge the nult data frame. The receiver STA can resend the null data frame if the expected ACK frame is not received (i.e., “timed out”). The protocol transactions are shown in FIG. 8 . The network allocation vector (NAV) of the ACK frame is enlarged by the sum of SIFS and the time to transmit the new null data frame. The receiver STA may also send the null data frame using ordinary DCF.
[0061] FIG. 10 shows the sender STA's process to determine when to enter a doze mode, in response to the receiver STA's process described above in conjunction with FIG. 9 . In this embodiment, the sender STA keeps two lists: the s-list and the f-list. The s-list includes all STAs that the sender receives an ACK frame in response to its ATIM frame during the ATIM window (step 1001 ). Correspondingly, the f-list includes all STAs from which no ACK frame was received during the ATIM window (step 1002 ). After the ATIM exchange period, the sender STA sends data frames to STAs both in the s-list and f-list (step 1006 ). If a data frame transmission to an STA on the f-list fails, the corresponding STA is removed from the f-list. However, if an ACK frame is received from an STA on the f-list, the STA is transferred from the f-list to the s-list. Thus, at some point in time during the beacon interval, the f-list becomes empty.
[0062] The sender STA sends data frames to the STAs in the f-list and s-list with the “more data” fields properly set. In this embodiment, the sender STA retransmits a data frame if a corresponding ACK frame is not received within an expected time. Further, in the last data frame to an STA, the sender STA sets the “more data” field to ‘0’ (step 1007 ). Then, the sender STA waits for notification from the receiver STA as to whether the receiver STA has data for the sender. As described above, the “more data” field in the ACK frame returned from the receiver STA in response to the sender STA's last data frame is set to ‘0’ only when the receiver STA has no data for any of its neighbors (step 1008 ). At that point, the receiver STA is removed from the sender's s-list (step 1012 ). However, if the “more data” field in the ACK frame is set to ‘1’, the sender STA expects to receive more specific information from the receiver STA in subsequent frames. If the next frame from the receiver STA is a null data frame and the “more data” field is set to ‘0’ (step 1010 , corresponding to step 912 of FIG. 9 ), there is no more data from the receiver STA to the sender STA. At that point, the receiver STA may be removed from the s-list. Otherwise, the sender STA expects additional data frames from the receiver STA. After these processing, the receiver STA is removed from the s-list. If the sender STA expects data frames from the receiver STA, the sender adds the receiver STA to its peer list (step 1012 ). The peer list includes all STAs that the sender STA expects data frames. The sender STA waits for all the STAs in the peer list to complete their transmissions to the sender STA (steps 1003 , 1004 ). When the transmissions are complete, the sender STA goes into a doze mode.
[0063] In the general case, an STA is both a sender and a receiver within a beacon interval. In that case, the STA follows the sender STA's process to sends out data packets and the receiver STA's process when it receives data frames. The STA only enters a doze mode when it finishes all its transmissions and receptions. In the case when two peers send to ATIM frames to each other during the ATIM window, or send data frames to each other subsequent to the ATIM window, both STAs consider the other as peers and their states can be communicated through the “more data” fields in their respective outgoing data frames. Therefore, upon receiving a data frame, the receiving STA may omit the unicast null data frame to signal completion of transmission to the other STA (i.e., step 912 of FIG. 9 ). Thus, the processes of FIGS. 9 and 10 also govern when two STAs are both senders and receivers to each other.
[0064] According to a second embodiment of the present invention, STAs may send multicast or broadcast messages. In this embodiment, no STA operates in the promiscuous mode. Under existing 802.11 wireless networks, an STA sending out a multicast or broadcast frame is awake throughout the beacon interval. Because the multicast or broadcast frame is received by a number of STAs, the receiver STAs derive the sender STA's awake state. As a result, data frames may be sent to an STA that sends out a multicast or broadcast frame without announcement using ATIM frames.
[0065] For a sender STA of a multicast or broadcast frame, there are many choices as to when to enter a doze mode. In one approach, the sender STA may enter a doze mode immediately after finishing its transmissions. The sender STA may complete its multicast or broadcast transmission as specified in the existing 802.11 standard. Under this approach, unless an ATIM frame is received during the ATIM window, the sender STA does not wait for possible transmissions from the multicast or broadcast receivers. For its unicast transmissions, the STA follows the same process as described above with respect to FIGS. 6-10 . Upon completion of the unicast and multicast communications, the STA enters a doze mode. In that case, there is no special provisions for multicast or broadcast transmissions.
[0066] In another approach, the sender STA may wait to enter the doze state until after it has received all the data frames to be sent by its receivers. This second approach requires that the multicast or broadcast sender STA has correct state information of all of its receivers to successfully enter a doze mode. FIG. 12 shows one method under this second approach for a multicast or broadcast sender STA to enter a doze mode. As shown in FIG. 12 , the sender STA completes both its unicast sending and reception (step 1201 ) and multicast transmission (step 1202 ), setting the “more data” field to ‘1’ in the data frames if it has more data to send, and setting the “more data” field to ‘0’, at the final data frame. Multicast or broadcast frames are not acknowledged.
[0067] Upon completing the activities of steps 1201 and 1202 , the sender STA may decide to enter a doze mode (step 1203 ). To prepare to enter the doze mode, the sender STA first sends out a multicast null data frame to all its neighbors (step 1204 ). The multicast null data frame is intended to solicit response (in the form of ACK frames) from the receiver STAs that have data frames to send to the sender (step 1205 ). Upon receiving the multicast or broadcast null data frame from the sender, a receiver STA that still has data to send to the sender STA sends an ACK frame to the sender STA after SIFS time, setting the “more data” field of the ACK frame to ‘1’. Using the process discussed below in conjunction with FIG. 11 , the sender STA is able to determine if there is (1) no ACK frame (step 1206 ), (2) exactly one ACK frame (step 1207 ), or (3) multiple ACK frames (step 1208 , in the form of an ACK frame collision). The sender STA enters the doze mode if there is No ACK frame (i.e., none of the receiver STAs has a data frame to send to the sender STA).
[0068] If there is exactly one ACK frame, the sender STA waits for the data frames from the sender STA of the ACK frame (step 1209 ). The transmission between the multicast or broadcast sender STA and its receiver STA may complete using a protocol discussed above, for example. Thereafter, the multicast or broadcast sender may enter the doze mode. The multicast or broadcast sender STA may send out a notification frame in which a “power management” field in an appropriate header is set to indicate that the sender STA is going into a power-saving mode (step 1210 ).
[0069] In the case of an ACK collision (i.e., step 1208 , corresponding to two or more receiver STAs having data to send the multicast or broadcast sender STA), the sender STA waits for at least two STAs to finish their data frame transmissions to the sender STA. Thereafter, the sender STA resends the multicast null data frame, repeating steps 1204 - 1208 .
[0070] To make the determinations of steps 1206 - 1208 requires the multicast or broadcast sender STA to differentiate the collision of ACK frames from no ACK frame transmission. To do so, the sender STA measures whether or not the transmission power exceeds a threshold within an ACK transmission period that begins after a SIFS time from the time the multicast null data frame completes transmission. FIG. 11 is a flow chart that illustrates how a multicast sender STA may determine the ACK frame received in response to a multicast notification frame. As shown in FIG. 11 , the multicast or broadcast sender STA first determines if a proper ACK frame is received during the ACK transmission period (step 1101 - 1103 ). If not (step 1104 ), the sender STA determines whether the received signal power exceeds a pre-determined average noise power threshold. If a higher power than the noise power threshold is received (step 1105 ), the sender STA considers an ACK collision as being detected. Otherwise (step 1106 , i.e., a lower power than the noise power threshold is received), the sender STA considers that as having no ACK frame received.
[0071] In an alternative approach, the multicast null data frame is not acknowledged. FIG. 13 shows a process under this alternative approach by which a multicast or broadcast sender STA enters a doze mode. As shown in FIG. 13 , after completing the unicast sending and receiving activities (step 1301 ) and multicast or broadcast transmission (step 1302 ), the multicast or broadcast sender STA decides to enter a doze mode (step 1303 ), similar to those activities described above in conjunction with steps 1201 - 1203 of FIG. 12 . The multicast or broadcast sender then sends a multicast null data frame with the “more data” field set to ‘1’, and initiates a timer (steps 1304 , 1305 ). In this embodiment, when a receiver STA that has data frames to be transmitted to the multicast or broadcast sender receives the null data frame, the receiver advances the data frames for the multicast or broadcast sender ahead of other data frames the receiver intends to send. Thus, when such a receiver STA next seizes the channel for packet transmission, a data frame destined to the multicast sender STA is sent.
[0072] If no data frames are received before the timer expires (step 1306 ), the multicast sender STA enters the doze mode (step 1311 ). However, if a data frame arrives, the multicast sender STA then includes the sending STA into its peer list (step 1307 ), if it is not already on the peer list. The multicast sender STA and this sending STA may exchange data transmission traffic information using the processes discussed above (e.g., processes illustrated in FIGS. 9 and 10 ). Additional data frames from other STAs may also arrive prior to this exchange between the multicast sender and the sending STA completes. The multicast sender STA includes these additional STAs to its peer list as the data frames arrive. At the same time, the multicast sender removes STAs that have finished transmission from the peer list (step 1308 ). This process continues as the receiver STAs complete their transmissions to the multicast or broadcast sender. When the peer list is empty (step 1309 ), the multicast sender then sends out another null data frame again to determine if it can enter the doze mode. Steps 1304 - 1310 are repeated until either the sender enters the doze mode at step 1311 , or a new beacon interval begins.
[0073] In yet another embodiment, every STA in an ad hoc wireless network operates in the promiscuous mode during the ATIM window, whereby every STA listens to the ATIM/ACK exchanges among the other STAs. Therefore, even though an STA does not have an ATIM/ACK exchange with any or all of its neighbors, the STA may still derive the power-saving modes of its neighbors by observation. With this knowledge of the neighbors power-saving states, the STA may send out frames to any of its neighbors believed to be in an awake mode. To enter a doze mode, an STA determines whether or not its neighbors may send it data packets. In such an embodiment, the method's of FIGS. 6-13 are possible. For example, an STA may use the methods of FIGS. 6-10 to exchange information with other STAs that it has exchanged ATIM/ACK frames during the ATIM window. When the STA has sent out multicast or broadcast data frames, the methods of FIGS. 11-13 may be used. Thus, when the STA desires to enter a doze mode, in one instance, it may enter the doze mode after its data transmissions and completing the traffic announced in the ATIM window, without query of its neighbors for possible data frames. In another instance, the STA may send a broadcast null data frame with a power management field set to ‘0’ to notify its neighboring STAs that it intends to enter a doze mode. The neighboring STAs may respond using the methods of FIG. 11-13 , for example.
[0074] The detailed description above is provided to illustrate the specific embodiments of the present invention and is not intended to be limiting. Various modifications and variations within the scope of the present invention are possible. The present invention is set forth within the scopes of the following claims.
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Methods for increasing power saving in a station that sends or receives frames in an ad hoc wireless network (e.g., IBSS), while allowing the station to enter a power-saving mode quickly upon completion of scheduled tasks. At the same time, a method of the present invention allows two stations in the ad hoc wireless network to infer each other's power management mode without requiring an ATIM/ACK exchange between the STAs within an ATIM window. Consequently, a station may enter a power-saving mode promptly without impairing the station's ability to receive packets. In one embodiment, a “more data” field is used between stations to exchange information. Stations with various computation abilities provide information under different time constraints. The stations may enter power-saving modes that send multicast/broadcast frames or use promiscuous mode within an ATIM window.
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BACKGROUND OF THE INVENTION
The present invention relates to performance improving additives of long chain alcohols for surfactant foaming solutions which are injected in conjunction with steam or carbon dioxide floods to improve conformance.
When an oil reservoir is subjected to steam injection, steam tends to move up in the formation, whereas condensate and oil tends to move down due to the density difference between the fluids. Gradually, a steam override condition develops, in which the injected steam sweeps the upper portion of the formation but leaves the lower portion untouched. Injected steam will tend to follow the path of least resistance from the injection well to a production well. Thus, areas of high permeability will receive more and more of the injected steam which further raises the permeability of such areas. This phenomenon exists to an even larger degree with low injection rates and thick formations. The steam override problem worsens at greater radial distances from the injection well because steam flux decreases with increasing steam zone radius.
Although residual oil saturation in the steam swept region can be as low as 10%, the average residual oil saturation in the formation remains much higher due to poor vertical conformance. Thus it is because of the creation of steam override zones that vertical conformance in steam floods is usually poor.
A similar conformance problem exists with carbon dioxide flooding. Carbon dioxide has a large tendency to channel through oil in place since carbon dioxide viscosity may be 10 to 50 times lower than the viscosity of the oil in place. This problem of channeling through oil is exacerbated by the inherent tendency of a highly mobile fluid such as carbon dioxide to preferentially flow through more permeable rock sections. These two factors, unfavorable mobility ratios between carbon dioxide and the oil in place and the tendency of carbon dioxide to take advantage of permeability variations, often make carbon dioxide flooding uneconomical- Conformance problems increase as the miscibility of the carbon dioxide with the oil in place decreases.
Although not much attention has been devoted to carbon dioxide conformance, it has long been the concern of the oil industry to improve the conformance of a steam flood by reducing the permeability of the steam swept zone by various means. The injection of numerous chemicals such as foams, foaming solutions, gelling solutions or plugging or precipitating solutions have been tried. Because of the danger of damaging the reservoir, it is considered important to have a non-permanent means of lowering permeability in the steam override zones. For this reason, certain plugging agents are deemed not acceptable. In order to successfully divert steam and improve vertical conformance, the injected chemical should be (1) stable at high steam temperatures of about 300° to about 600° F., (2) effective in reducing permeability in steam swept zones, (3) non-damaging to the oil reservoir and (4) economical.
The literature is replete with references to various foaming agents which are employed to lower permeability in steam swept zones. The vast majority of the foaming agents in the prior art require the injection of a non-condensable gas to generate the foam in conjunction with the injection of steam and the foaming agent. U.S. Pat. Nos. 3,410,344 and 3,994,345 disclose the use of a steam foaming agent selected from the generic groups of polyethoxyalkanols and alkylaryl sulfonates to reduce permeability in steam channels. U.S. Pat. No. 4,018,278 discloses the use of sulfonated, ethoxylated alcohols or alkylphenols in surfactant flooding solutions without the use of steam.
Copending U.S. patent application Ser. No. 896,710, filed Jun. 10, 1992, now U.S. Pat. No. 5,209,367, discloses the use of fatty acids having about 12 to about 20 carbon atoms as additives to surfactant foaming solutions used in steam or carbon dioxide floods where the ratio of fatty acid to surfactant in the foaming solution is between about 1:4 to 3:2. Copending U.S. patent application Ser. No. 964,741 filed Dec. 24, 1992, discloses the use of fatty acid salts as steam foaming agents, and not additives to foaming systems in steam floods. The aqueous solution containing the fatty acid salts must have a pH between about 8 and about 12 and a salinity greater than about 1%.
SUMMARY OF THE INVENTION
The invention is an improvement to surfactant foam injection methods used to improve conformance in steam or carbon dioxide floods. When such foams are used, a surfactant foaming solution is injected to foam within the formation and reduce the permeability of swept and partially swept zones, forcing steam or carbon dioxide into unswept zones. The improvement comprises adding a long chain alcohol having about 8 to about 20 carbon atoms to the surfactant foaming solution in a concentration such that the ratio of alcohol to surfactant in the foaming solution is between about 1:6 and about 1:2.
The invention may be practiced wherever a surfactant foaming solution is employed, such as in a steam or carbon dioxide drive flood to production wells or in a cyclic flood involving injection and production through the same well.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph illustrating the pressure gradient response of a commercial α-olefin sulfonate steam foaming agent with and without the addition of a blend of linear alcohols having 12 to 15 carbon atoms.
FIG. 2 is a graph illustrating the pressure gradient response of a commercial α-olefin sulfate and a disulfonate steam foaming agent with and without the addition of a blend of linear alcohols having 12 to 15 carbon atoms.
FIG. 3 is a graph illustrating the pressure gradient response of the FIG. 1 system in the presence of 0.07 pore volumes of oil.
DETAILED DESCRIPTION
The invention additives for use in conjunction with steam foaming agents or carbon dioxide foaming agents are highly effective in reducing the permeability of flood swept zones. The invention additives increase the foaming capability and diversion capability of steam and carbon dioxide foaming agents. They also permit a number of steam and carbon dioxide foaming agents that do not foam well in the presence of residual oil to form stable foams. Tests have indicated this to be true over a range of residual crude saturation of 7% to 30%. Thus, certain additives that heretofore have been very limited in application may be used to foam in areas having some oil saturation that have not been completely swept by the steam or carbon dioxide flooding medium. Another advantage of using the invention is that the cost of the injected chemicals is significantly lowered because part of the usually expensive surfactant foaming agent is replaced with a low cost alcohol.
The novel additives of the present invention are alcohols having between about 8 and about 20 carbon atoms, preferably about 12 to about 15 carbon atoms. Chain lengths shorter than 8 carbon atoms are known to be less interfacially active. Thus, it is believed that the additive results would not be as good as those alcohols within the invention carbon range of 8 to about 20.
The ratio of surfactant foaming agent to alcohol is chosen such that the aqueous solution remains homogeneous at application temperature, salinity, and pH. Of course, depending upon the individual conditions and the foaming agent employed, the optimum ratio may vary significantly. Once the blend ratio range for homogeneous solutions is defined, the blend ratio should be further optimized within that range to determine what blend gives the fastest foam response under the application conditions. It is believed that the ratio of alcohol to surfactant should be between about 1:6 and about 1:2. general, with a ratio higher than 1:2 of alcohol to surfactant, there is probably not enough surfactant to keep the alcohol solubilized.
It is preferred to maintain the pH of the foaming agent/alcohol solution near neutral, or at least within the pH range of 6 to 10. The preferred solution pH of about 7 is approximately formation water pH for most underground hydrocarbon formations, which eliminates the difficulties of maintaining a different solution pH.
In carbon dioxide injection, however, formation pH will frequently drop as low as 3. Depending on the system, this may create difficulties for the invention method. Although a lower pH and higher brine levels normally associated with carbon dioxide flooded formations will not substantially affect the solubility of alcohol, the pH and salinity will have an effect on how much alcohol the surfactant can solubilize. Under such circumstances, it is believed that the preferred alcohol additives will be in the lower range of alkyl chain length of 8 to 14 carbon atoms.
There are two general classes of foaming agents commercially available for steam foaming and carbon dioxide foaming operations. These are α-olefin sulfonates and alkylaryl sulfonates. In laboratory tests, the alcohol invention additive proved effective with both general types of foaming agents. It is believed that the invention additive method will also prove effective with other types of foaming agents known in the art including various alkoxysulfates, alkoxycarboxylates, and other sulfonates.
U.S. Pat. No. 5,027,898 discusses numerous variations of using steam and carbon dioxide foaming agents that are known in the art. The inventor is unaware of any reason why the invention method would inhibit the use of any of these variations in using steam and carbon dioxide foaming agents or why these variations would inhibit the use of the invention method.
The following examples will further illustrate the novel alcohol additive method of the present invention for steam and carbon dioxide foaming agents. These examples are given by way of illustration and not as limitations on the scope of the invention. Thus, it should be understood that the composition and concentration of the additives may be varied to achieve similar results within the scope of the invention.
EXAMPLES
FIG. 1 illustrates the pressure gradient response obtained when a 0.5% by weight 16 to 18 carbon atom α-olefin sodium sulfonate (1618AOS) in Kern River softened water with a pH of 7 was injected with nitrogen gas at 150° C. into a sandpack. The nitrogen gas and surfactant had a superficial velocity of 10 meters per day in the 2 foot by 1.5 inch, 6 Darcy linear sandpack. The sandpack contained 0.30 pore volumes of heavy California crude, about 0.42 pore volumes of Kern River softened water and about 0.28 pore volumes of nitrogen. The Kern River softened water is relatively fresh, containing about 800 ppm Total Dissolved Solids (TDS) which includes about 320 ppm sodium chloride, about 320 ppm sodium bicarbonate, and about 160 ppm sodium sulfate.
No substantial pressure gradient was observed after injecting the surfactant and nitrogen for about 24 hours. This is noted as a solid line at the bottom of FIG. 1. These results indicated that the ability of this surfactant to generate foam was severely hindered by the presence of oil.
FIG. 1 also shows the pressure gradient response obtained when 20% of the α-olefin sulfonate was replaced with a commercial blend of linear alcohols having 12 to 15 carbon atoms sold under the trademark "NEODOL 25" by Shell Chemical Co. (25-OH). Thus, the solution contained 0.4% of the α-olefin sulfonate and 0.1% alcohol by weight. All other experimental conditions were identical. A rapid pressure gradient response was observed along with the attainment of a large steady state pressure gradient of nearly 700 psig. These results indicate that the surfactant/alcohol blend can generate substantial quantities of strong foam in the presence of crude oil.
FIG. 2 illustrates the pressure gradient response obtained when a blend of 25% by weight 16 to 18 carbon atom α-olefin sodium sulfonate and 0.25% sodium diphenyl oxide disulfonate (C-16DPODS) was injected into a sandpack under the same conditions as FIG. 1.
No substantial pressure gradient was observed after injecting the surfactant blend and nitrogen for over 50 hours. The ability of this surfactant blend to generate a foam is severely hindered by the presence of oil. Under identical conditions, the surfactant blend generated pressure gradients of up to 600 psig when 20% of the surfactant blend was replaced with "NEODOL 25" to create a 0.2% α-olefin sulfonate, 0.2% diphenyl oxide disulfonate, and 0.1% by weight "NEODOL 25" solution. These results indicate that alcohols employed according to the invention can enhance the performance of foaming surfactants in the presence of crude oil for steam foaming operations.
FIG. 3 illustrates the pressure gradient responses of the FIG. 1 system under FIG. 1 conditions except that the amount of heavy California crude oil in the sandpack was reduced from 0.3 pore volumes to 0.07 pore volumes, and the other components within the sandpack were increased to 0.56 pore volumes of Kern River softened water and 0.38 pore volumes of nitrogen.
No substantial pressure gradient was observed after injecting surfactant and nitrogen for over 50 hours. But when 20% of the α-olefin sulfonate was replaced with the "NEODOL 25" alcohol resulting in a 0.4% α-olefin sulfonate and 0.1% "NEODOL 25" solution, a rapid pressure gradient was observed, and a large steady-state pressure gradient of over 600 psig was achieved.
Many other variations and modifications may be made in the concepts described above by those skilled in the art without departing from the concepts of the present invention. Accordingly, it should be clearly understood that the concepts disclosed in the description are illustrative only and are not intended as limitations on the scope of the invention.
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The invention is a method for increasing the effectiveness of steam or carbon dioxide foaming operations for improving conformance during steam or carbon dioxide floods by adding to the surfactant foaming solution an alcohol having about 8 to about 20 carbon atoms in a concentration such that the ratio of alcohol to surfactant in the foaming solution is between about 1:6 and about 1:2.
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FIELD OF THE INVENTION
This invention relates to a medical device for clamping the stomach in morbid obesity bariatric surgery.
BACKGROUND OF THE INVENTION
One of the most common illnesses is obesity. Many diseases are caused by or exacerbated by obesity, particularly in the western world, and these illnesses may be accompanied by physical and psychological disabilities. Surgical methods for controlling weight initially involved gastric stapling in various forms, which, over a prolonged period, resulted in major weight reduction. Because of the invasiveness of this type of surgery, and the irreversibility of it, the gastric stapling surgical technique was not widely accepted. These surgical procedures required a laparotomy which carried the risk of morbidity and death. Additionally, the gastric stapling technique required that the setting of the gastric restriction be initially set correctly because of the inability of the surgeon to modify the degree of restriction after the operation was performed. To overcome this difficulty, adjustable gastric banding was introduced which utilized an inflatable balloon carried by a band that could be placed around the stomach by an open operation or laparoscopically. The later technique has become the preferred surgical technique because of the reduced invasiveness of the operation. The degree of gastric restriction after placement of the band around the stomach immediately below the oseophagogastric junction was controlled by inflating an encircling balloon which was sealingly carried on the inner surface of the band; however, the bands of the prior art created the gastric restriction by annularly or hoop compressing the stomach. A possible consequence of annular stress is the inducement of erosion that permitted the band to go into the bowel thereby causing bleeding, infection, and even death. Thus, it is desirable to provide a stomach plication device that avoids annular stress, that utilizes inflatable members to prolong the life of the plication device, that is laparoscopically implantable, avoids erosion, and is adjustable to control the gastric restriction stoma after the operation is completed.
SUMMARY OF THE INVENTION
There is, therefore, provided according to the present invention a fluid inflatable clamp device to plicate the stomach for morbid obesity surgery and substantially reduce the risk of band erosion resulting form annular compression of the stomach. The inflatable device is adjustable and can be placed laparoscopically or by open operation.
The present invention is directed to embodiments that utilize opposing legs carrying an inflatable balloon member in one embodiment or balloons in other embodiments to permit clamping of the stomach below the grastroesphogeal junction. By selectively inflating or aspirating opposing balloons, the life of the clamp may be substantially prolonged and consequently the frequency of replacement surgery greatly reduced. The device is preferably made of silicone where the legs are so constructed and proportioned to have sufficient stiffness to permit limited bending and are so hinged such that the hinged ends of the legs are in fixed lateral spaced relationship.
In each of the embodiments of the invention, the fluid inflatable device to plicate the stomach is U-shaped and consists of a first leg or plate having a preferably rectangular shape where the first leg has a free first end and a hinged opposite end and an axis of elongation; a second leg having substantially the same configuration as the first leg also has a hinged end and free second end. The hinged ends of the legs are integrally connected to a laterally extending bight portion which has sufficient stiffness to retain the legs in fixed lateral spaced relationship at their hinged ends.
In the preferred embodiment, the first leg has a first lumen extending at least in part axially therein that communicates with a first inflation port and, likewise, the second leg has a second lumen extending at least in part axially therein that communicates with a second inflation port. However the second leg also has a third lumen extending axially therein that communicates with a bight lumen extending laterally through the bight portion where the bight lumen is in fluid communication with the first lumen. Thus, a flow path is provided that permits fluid flow for inflating or aspirating a first inflatable member that is peripherally sealed and extends axially along the inner surface of the first leg. A separate flow path is provided to permit fluid flow through the second lumen and second inflation port for inflating and aspirating a second inflatable member that is peripherally sealed and extends axially along the inner surface of the second leg; the second inflatable member is oppositely positioned from the first inflatable member when the stomach is clamped.
The embodiment above described further includes latch means associated with the first and second legs at their free ends to permit the legs to be locked in pre-determined fixed lateral relationship during the clamping of the stomach. Separate fluid flow paths are defined by first and second conduits which are contained within a flexible latch member having at least one serration where the flexible latch member is integrally carried by the second leg member adjacent its free end; the first conduit of the flexible latch member communicates with the second lumen and the second conduit of the flexible latch member communicates with the third lumen. Fluid supply means associated with the latch means permits saline fluid to be selectively supplied or aspirated through the first conduit to inflate or aspirate the first inflatable member to a pre-determined pressure. The second inflatable member may be separately inflated to a pre-determined pressure by the fluid supply means supplying or aspirating fluid through the second conduit of the flexible latch member. To secure the free ends of the first and second legs in substantially fixed lateral spaced relationship, the first leg has a latch cavity adjacent the free end so dimensioned and proportioned to permit locking engagement with a selected serration of the serrated flexible latch member.
In another embodiment of this invention, the inflatable device has as in the preferred embodiment a first leg, preferably of plate shape, an axis of elongation, a first end and a hinged end, a first inflation port, and a first lumen extending at least in part axially therein; a second leg having substantially the same rectangular plate configuration as the first leg, an axis of elongation, a hinged end, a free end, and a second lumen extending at least in part axially therein where the second lumen communicates with a second inflation port. The hinged ends of the legs are self hinged and integrally associated with a laterally extending bight portion where the bight portion has sufficient stiffness to retain the legs in fixed lateral spaced relationship at their hinged ends. The bight portion contains a laterally extending bight lumen that communicates with the first and second lumens thereby providing a fluid flow path to the first inflation port. The first inflatable member which is sealingly carried by the first leg extends at least in part axially on the inner surface of the first leg where the first inflatable member communicates with the first inflatable port. The second leg sealingly carries a second inflatable member which is oppositely positioned from the first inflatable member when the stomach is clamped between the first and second legs. As in the preferred embodiment above described, in this embodiment the serrated flexible latch member is carried by the second leg adjacent its free end and the flexible latch member contains a first conduit therein in fluid communication with the second lumen. To secure the free ends of the first and second legs in fixed space relationship, the first leg has a latch cavity adjacent to the free end that is so dimensioned and proportioned to permit locking engagement with a selected serration of the serrated flexible latch member. A fluid supply and aspiration means is associated with the serrated flexible latch member and communicates with the first conduit to selectively permit inflation or aspiration of both the first and second inflatable members.
In yet still another embodiment, the plication device is of similar construction as in the previous embodiments. As in the above described embodiments, the plication device is preferably U-shaped and has a first leg and a second leg which are preferably of a rectangular plate shape and self-hinged to the bight portion so as to permit the legs to articulate with respect to the bight portion. An axis of elongation extends through the first leg, bight portion, and second leg and a single inflatable member is sealingly carried and extends axially and continuously on the inner side of the first and second legs and bight portion. The first leg has a first lumen that communicates with an inflation port that is in fluid communication with the single inflatable member. As in the above described embodiments, a flexible latch member is associated with the first and second legs for spacing the legs in substantially fixed spatial relationship where the flexible latch member contains at least one serration. The flexible latch member has a first conduit therein that is in fluid communication with the first lumen. A fluid supply means, as described in the above embodiments, is associated with the flexible latch member for selectively supplying and aspirating fluid through the first conduit to inflate or aspirate the inflatable member to a pre-determined pressure or lateral distance from the inner surfaces of the first and second legs
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages will become appreciated as the same become better understood with reference to the following specification, claims and drawings wherein:
FIG. 1 is a perspective view of the preferred embodiment of the stomach plication device of this invention for morbid obesity surgery illustrating the device open and latched configurations.
FIG. 2 is a side view of FIG. 1 illustrating the preferred embodiment in the unlatched open configuration.
FIG. 3 is a side view of FIG. 1 illustrating the preferred embodiment of this invention in a latched configuration with the stomach plicated.
FIG. 4 is a front view of FIG. 3 .
FIG. 5 is a rear view of FIG. 3 .
FIG. 6 is a top view of FIG. 3 .
FIG. 7 is a perspective view of the preferred embodiment illustrating the device in latched configuration with the stomach plicated.
FIG. 8 is a side view of another embodiment of this invention.
FIG. 9 is a front view of FIG. 8 .
FIG. 10 is a rear view of FIG. 8 .
FIG. 11 is a top view of FIG. 8 .
DETAILED DESCRIPTION
FIG. 1 is a perspective of the preferred embodiment illustrating the stomach plication device 1 of this invention in both latched and unlatched configurations. As can be seen in FIG. 1 , the first leg 2 is shown in phantom to depict the unlatched configuration; and the latched, closed configuration, is shown in solid lines. In the preferred embodiment the frame 5 of plication device 1 is U-shaped having a pair of opposing legs or rectangular plates interconnected by a bight and made of a silicone material. The frame consists of first leg or rectangular plate 2 which has a free-end 3 and a hinged-end 4 . Hinged-end 4 is integrally connected and self-hinged to bight portion 6 . First leg 2 is so constructed and proportioned to have sufficient stiffness to permit limited bending and to have sufficient flexibility at the juncture of the first leg and bight portion to rotate with respect to bight portion 6 at its hinged end 4 . Bight portion 6 is also shaped rectangularly and is preferably made of a stiff silicone material with sufficient flexibility at the juncture of second leg 7 and bight portion 6 so as to form self-hinging joint 8 ; bight portion 6 is of sufficient stiffness such that the lateral distance between the hinged end 4 of first leg 2 and hinged end 9 of second leg 7 is essentially constant.
Referring to FIGS. 1 and 2 , it can be seen that second leg 7 has a free-end portion 11 that contains flexible latch member 12 which is bendable with respect to second leg 7 and consists of a multiplicity of serrations 13 to permit the forming of an adjustable latch lock with first leg 2 . To form the latch lock, the serrations 13 are sequentially advanced through latch cavity 14 until a desired lateral separation between first leg 2 and second leg 7 is achieved. Each of the serrations 13 and latch cavity 14 are so dimensioned and constructed such that when a serration sufficiently engages latch cavity 14 , the serration cannot be withdrawn back through the latch cavity.
Referring again to FIGS. 1 and 2 , it can be seen that, first leg 2 has an axis of elongation 16 and second leg 7 has an axis of elongation 17 . First inflatable member 18 is carried by first leg 2 and extends axially along inner surface 19 of the first leg. First inflatable member 18 is peripherally sealed to inner surface 19 and is selectively inflatable, preferably with saline fluid, to a desired lateral distance from inner surface 19 such as that illustrated in FIG. 2 by phantom line 21 . In a like manner, second inflatable member 22 is peripherally sealed to inner surface 23 and extends axially along inner surface 23 of second leg 7 and is selectively inflatable with a saline fluid to a desired lateral dimension as illustrated in FIG. 2 by phantom line 24 . In the preferred embodiment, first and second inflatable members are separately inflatable as hereafter described by reference to FIGS. 3 , 4 , 5 , and 6 .
As can be seen is FIG. 3 , the stomach 36 is plicated between first leg 2 and second leg 7 by inflation of second inflatable member 22 . First inflatable member 18 as shown in FIG. 3 has not been inflated while second inflatable member 22 is inflated to illustrate that either inflatable member or both can be used to further plicate the stomach 36 between the first and second legs.
The flow paths for inflating and aspirating inflatable members 18 and 22 , and the corresponding inflation ports, can be seen by reference to FIG. 3 . First leg 2 has a first inflation port 26 that communicates with first inflation member 18 . Saline fluid for inflating first inflation member 18 is supplied from reservoir 40 through first conduit 27 that extends axially within flexible latch member 12 and communicates with third lumen 28 . A fluid flow path is provided to first inflation port 26 by third lumen 28 which extends axially within and through second leg 7 and communicates with bight lumen 29 . Bight lumen 29 extends laterally through bight portion 6 and in turn communicates with first lumen 31 ; first lumen 31 extends in part axially within first leg 2 completing the flow path to first inflation port 26 . To inflate second inflatable member 22 , a separate flow path is provided through second conduit 32 which extends axially through flexible latch member 12 and communicates with second lumen 33 ; second lumen 33 extends at least in part axially within second leg 7 and communicates with second inflation port 34 . Thus, saline fluid may be separately supplied to inflate or aspirate second inflatable member 22 to a desired lateral dimension.
Referring now to FIG. 7 , which is a perspective view of the preferred embodiment, stomach 36 is shown to be plicated between first leg 2 and second leg 7 with second inflatable member 22 sufficiently inflated to define a gastric restriction stoma. Although not shown in the drawings, a reservoir 40 is implanted in the patient and contains saline. Reservoir 40 communicates with conduits 27 and 32 which are contained within silicon tubing 37 . Reservoir 40 is implanted during the operation within the left rectal muscle bed. The use of a silicone implanted reservoir to supply saline to inflate or aspirate a balloon is well known in the prior art and widely used in lap band gastric surgical procedures. The reservoir is attached to the anterior rectal sheath by absorbable sutures. After the operation is completed, the gastric restriction stoma can be modified according to a patient's need. This is accomplished by use of a needle selectively inserted into injection ports carried by the reservoir. The reservoir has two injection ports located under the skin which can be localized radioscopically; the needle is then introduced into a respective port to inflate or aspirate the inflatable member communicating with that port. The preferred embodiment permits the surgeon after the plicating device has plicated the stomach to selectively inflate or aspirate either or both inflatable members to modify the gastric restriction stoma.
Another embodiment of this invention is illustrated in FIGS. 8 , 9 , 10 , and 11 . The basic distinction between this embodiment and the preferred embodiment described above is that a single inflatable member 38 , shown in FIG. 8 , is utilized rather than two separately inflatable members. By referring to FIG. 8 , it can be seen that inflatable member 38 extends axially along the inner surface 19 ′ of first leg 2 ′, laterally along the inner surface 39 of bight portion 6 ′, and axially along the inner surface 23 ′ of second leg 7 ′. Single inflatable member 38 is peripherally sealed to the inner surfaces of first leg 2 ′, bight portion 6 ′, and second leg 7 ′; the expansion of single inflatable member 38 upon inflation is shown in FIG. 8 by phantom line 41 . Inflation and aspiration of single inflatable member 38 is illustrated by reference to FIGS. 8 , 9 , and 11 . As can be seen in FIG. 11 , a single conduit 42 extends within and through flexible latch member 12 ′ and as shown in FIG. 8 communicates with lumen 43 which extends at least in part axially within second leg 7 ′ and communicates with inflation port 34 ′. Although not shown, a saline reservoir is implanted in the patient and communicates with conduit 42 to supply and aspirate saline to and from single inflatable member 38 . As described above in the description of the preferred embodiment, the use of a silicone implanted reservoir 40 to supply saline to inflate or aspirate a balloon in lap band gastric surgery is well known. The reservoir is implanted during the operation within the left rectal muscle bed. After the operation is completed, the gastric restriction stoma can be modified by locating a reservoir injection port radioscopically and introducing a needle into the port to inflate or aspirate the inflatable member.
In yet another embodiment of this invention, not shown, the plication device is U-shaped and utilizes first and second inflatable members which are peripherally sealed and carried on the inner surface of the first and second legs, respectively as in the preferred embodiment; however, the device in this embodiment has a single fluid flow path to inflate the first and second inflatable members. The flow path consists of a conduit within the flexible latch member that communicates with reservoir 40 , a first lumen that extends at least in part axially within the first leg, a bight lumen that extends laterally within the bight portion, and a second lumen extending axially within the second leg. The first and second inflatable members communicate with a respective inflation port and the inflation ports are in fluid communication with the first and second lumens. And as above described, the use of a silicone implanted reservoir 40 which is well known in the prior art permits inflation and aspiration of the first and second inflatable members. The gastric restriction stoma may be modified after the stomach is plicated and one of the flexible latch member serrations locked with respect to the first and second legs. As in the above described embodiments, reservoir 40 has an injection port that can be located radioscopically and accessed by a needle to supply or aspirate saline to inflate or aspirate the inflatable members.
While I have shown and described embodiments of a stomach plication device for morbid obesity surgery, it is to be understood that the invention is subject to many modifications without departing from the scope and spirit of the claims recited herein.
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A medical device for clamping the stomach in morbid obesity surgery consists of a silicone frame that is essentially U-shaped, having opposing legs self-hinged to a bight portion interconnecting the legs. The opposing legs have sufficient stiffness to permit limited bending and have inner surfaces that sealingly carry an inflatable balloon which can be selectively inflated or aspirated after the device has been clamped to the stomach to adjust the gastric restriction stoma. A flexible latch member carried by one of the legs has at least one serration which is inserted into a latch cavity of the opposing leg to lock the opposing legs in fixed spaced relationship. Lumens within the legs communicate with a fluid supply source and respective inflatable balloon for selective inflation or aspiration of the inflatable balloons.
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BACKGROUND OF THE INVENTION
"Clean rooms" are required in hospitals, laboratories, and industrial operations wherever it is necessary to maintain a work environment substantially free of particles suspended in the air. The most common form of these installations involves a group of filter modules defining a major portion of the ceiling area of a room, which provide an inflow of filtered air proceeding to a convenient outlet, usually near the floor. Each of the modules is essentially a housing accommodating a conventional filter element having a rectangular box-like configuration. These are standard, and must necessarily be replaced frequently. Since "clean" atmospheric conditions are defined in terms of suspended particles having dimensions on the order of a few microns, it is of crucial importance that the modular units provide an absolute minimum of passages or recesses through or in which such particles can move or accumulate. The outlet opening from which air emerges after moving through the filter element is normally covered by a protective grille, which becomes an inviting location for particles to accumulate during periods in which the air may be stagnant within the room. When the air flow through the filter modules is turned on, such accumulations are obviously subject to disturbance and discharge back into the room. Recesses at fastenings that are exposed to the room also present problems. Replacement of the filter element involves withdrawing it through the opening normally occupied by the grille, and replacing it in the reverse of this procedure. Such action also obviously tends to disturb any accumulations of particles that may have found a way into recesses of any description in the adjacent area.
The importance of "clean room" installations has generated enough attention to produce quite a number of structural arrangements in the filter modules. These have displayed a considerable difference one from another in their functioning characteristics with regard to cost and the relative tendency to entrap and redistribute particles in the room space during service and maintenance operations, and at times when the air flow system is turned on after periods of stagnation.
The present application presents an improvement on the U.S. Pat. No. 4,088,463 of Irwin M. Smith, issued on May 9, 1978. That application is now owned by the present applicant. Problems encountered during the removal and replacement of the filter modules, and in cleaning the grilles in the structure disclosed in the Smith application, have resulted in the present development.
SUMMARY OF THE INVENTION
The housing of a filter module has a receptacle defining a space very slightly greater than that required by a standard replaceable filter element, and has a lateral extension adjacent the outlet opening of the module providing space for securing means for holding the filter element in position. The lateral extension also defines an opening for the grille, which is somewhat larger than the adjacent dimensions of the receptacle, so that the grille opening renders the filter element securing means accessible easily to a workman standing in the room served by the assembly of modules. The grille is then received in flush relationship in its housing opening, and is hinged to it on one side within the confines of the lateral extension of the housing. Preferably on the opposite side of the unit, a disengagable fastening (preferably a spring latch) interengages with the grille, thus completely concealing all fastenings and moveable components from exposure to the general stream of filtered air. The grille is also sealed directly to the filter element, which causes all of the filtered air discharged to move through the grille, rather than around it and into the spaces occupied by the hinge and the spring latch. The hinge is disengagable, permitting the grille to be removed bodily, cleaned, and reinstalled without disturbance to the filter element or its securing means.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a filter module, which is essentially that of the outer housing.
FIG. 2 is a top view with respect to FIG. 1.
FIG. 3 is a sectional elevation on an enlarged scale on the plane 3--3 of FIG. 2.
FIG. 4 is a sectional elevation on an enlarged scale on the plane 4--4 of FIG. 2.
FIG. 5 is an exploded view showing the components of the module assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring particularly to FIGS. 1, 2, and 5, the illustrated module includes the housing generally indicated at 10, the duct collar 11 containing the variable damper 12, the standard filter element 13, and the grille 14. The damper control unit 12 is absent from FIG. 2. The housing 10 defines a receptacle 15 having a rectangular configuration slightly larger than the dimensions of the filter element 13. The upper portion 16 of the housing defines a space between the filter element and the duct connection provided by the collar 11 within which the air flow is equalized across the top of the filter element 13 so that the full area of the filter element can be utilized. It is often desirable to provide insulation material as shown at 17 in FIG. 3 around the portion 16 of the housing.
Referring now particularly to FIGS. 3 and 4, the housing 10 has a lateral extension indicated at 18 extending on at least the two opposite sides of the housing, and preferably around the periphery. The offset 19 of the lateral extension 18 provides the inner recess surface 20, which defines a space in conjunction with the inside surface of the shelf 21. This shelf terminates in a flange 22 extending toward the surface 20. The flange 22 defines the opening receiving the grille 14, which extends laterally beyond the receptacle 15 to expose a substantial portion of the recess surface 20 to access from below. This is utilized for the installation and removal of the screws 23 holding the retaining clips 24 in place, which have a fulcrum offset 25 bearing against the recess surface 20. The clips overlay part of the width of the frame member 26 of the filter element 13. Some sort of fixed nut of conventional design, as shown at 27, is preferably installed in the sheet metal forming the offset 19 to provide adequate threaded engagement with the screws 23. A gasket, preferably of resilient sponge-like material, is shown at 28, and the limitation of the length of the clip 24 to less than the full width of the filter frame member 26 permits the resilience of the gasket material 28 to embrace the clip to the point where air flow around it is blocked.
At the junction of the portions 15 and 16 of the housing, a bearing edge is provided by the fold 29 in the sheet metal forming the upper part 16 of the housing. The flange 30 is bent outward from this material, and is secured to the overlapping flange 31 of the housing portion 15 by sheet metal screws as shown at 32. The resilient sponge-like gasket 33 is conventional, and normally is provided with the filter element 13. Tightening of the screws 23 serves to press the filter element 13 against the edge 29 to provide an effective seal causing all of the air moving within the portion 16 of the housing to pass through the filter element 13, rather than around it. The construction of the junction between the portions 15 and 16 of the housing constitutes an extremely effective and economical use of material, and results in a very simple assembly technique.
When the filter element 13 has been installed in the receptacle 15, and held in place by the subsequent installation of the clips 24 and the screws 23, the grille 14 may be closed to the position shown in FIG. 3. Preferably at least two offset arms as shown at 34 and 35 are bonded to the peripheral frame 36 of the grille 14, and extend over the flange 22 of the shelf 21. The offset ends 37 of these clips bear on the inside surface of the shelf 21. The offset ends, in conjunction with the flange 22, form a hinge connection permitting the grille unit to be swung downward in a clockwise direction, as viewed in FIG. 3. A conventional spring latch has components 38-39 mounted on the frame of the grille, and mating components as shown at 40 mounted in opposite positions on the portion 19 of the housing. These latches may be of any convenient design, and provide for retention of the right side of the grille, as shown in FIG. 3. A light pulling action on the grille, delivered either manually, or with instruments interengaging the grille openings, will suffice to pull the right side of the grille downward by disengaging the resilient securing effect of the latch assemblies. The configuration of the clip ends 37 and the flange 22 at the opposite edge also provides for complete removal of the grille so that it can be washed separately without disturbing the filter element 13. The space defined between the portions 19 and 21 of the housing can also be cleaned without removal of the filter element. It is important that the grille is held in position by a system that does not present any exterior fastenings that have to be manipulated during the grille-removal process, and which would be exposed to the main flow of air through the filter element and into the room. The gap between the grille and the shelf 22, particularly in view of its placement outside the air flow path, has a minimal tendency to accumulate particles. Under severe design requirements, further gasketing could be easily incorporated between the edge of the grille frame 36 and the adjacent flanges 22, although this is normally not necessary.
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A filter module has a housing providing a receptacle for a standard filter element, and also has a lateral extension for accommodating securing means to hold the filter element in place. The lateral extension defines a grille opening for removeably receiving an outlet grille in flush relationship, the grille opening extending laterally beyond the receptacle. A seal gasket closes the space between the grille and the filter element, embracing the securing means.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Patent Application Ser. No. 62/097,817, entitled CART SUSPENSION SYSTEM, filed on Dec. 30, 2014, all of the teachings of which are incorporated herein by reference.
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not Applicable
BACKGROUND
[0003] The present disclosure is generally directed toward a suspension system, and more specifically to a suspension system for a cargo dolly adapted to maintain a loading deck of the cargo dolly at a prescribed height as cargo is loaded onto the dolly, and subsequently, unloaded from the dolly.
[0004] The transport of perishable cargo by aircraft is well-known in the art. In this regard, such perishable cargo, which can encompass any type of product that must be maintained in a temperature-controlled environment, can only be efficiently and timely delivered by aircraft in many parts of the world. In fact, shipping via air may be the only viable option of transporting many types of perishable goods. Exemplary of such type of goods include fresh produce, seafood, meat products, blood and a variety of other temperature-sensitive medications, such as vaccines and the like. Perishable cargo will also encompass many other types of products well-known to those skilled in the art.
[0005] While in some cases, the duration that perishable cargo must go without being refrigerated (or heated) is of so short duration as to not affect the cargo, in many other instances perishable cargo will go for sufficient lengths of time from when delivered in a refrigerated condition at the airport to when the cargo is actually loaded on a plane. In this latter scenario, failure to continue providing adequate environmental control will cause the cargo to start spoiling, completely spoil, or otherwise become unusable for its intended purpose. Such phenomena occur very frequently with respect to food items and other heat sensitive materials such as blood and other biological/pharmaceutical products. The frequency that such damage occurs is also substantially high in areas having extremely hot climates as occurs in major cities in the states of Arizona, Nevada, New Mexico, and Texas during the summer months. Numerous other cities throughout the world likewise experience such extreme temperatures.
[0006] In practice, perishable cargo is typically containerized at refrigerated terminals and held in refrigeration until the same is transported to airlines, typically via refrigerated roller floor trucks, prior to flight time. As soon as such trucks are unloaded at the designated terminal at the airport, airline containers containing perishable cargo are first weighed and then placed into open container transport dollies for transport to the aircraft. At such point in the shipping process, however, the perishable cargo is no longer maintained in a temperature-controlled environment. As is well-known to those skilled in the art, such point in the transport of such cargo is referred to as a breaking in the “cool chain” where the perishable cargo is vulnerable to the temperatures of the external environment. During such time, the airline containers containing such perishable cargo will sit upon such open transport dollies, in some cases for up to four or more hours, and often times will be exposed to direct sunlight and extreme temperatures before ultimately being loaded into an aircraft for departure.
[0007] Such interval makes the perishable cargo especially vulnerable and it is during such time that substantial damage can occur by virtue of being exposed to a non-temperature controlled environment. In this regard, from the time that the temperature-controlled cargo is delivered to the airport and ultimately loaded on a plane, where the cargo is kept out of direct sunlight and at least protected to some extent by air conditioning, presents a significant risk that often times causes irreparable damage to the cargo resulting in substantial financial losses and property destruction.
[0008] These same issues also arise with respect to perishable air cargo being unloaded from aircraft. As discussed above, such interval from when the perishable cargo is unloaded from the aircraft to the time from when the same is ultimately stored in a temperature-controlled environment places such perishable cargo at substantial risk.
[0009] In addition to the foregoing problems associated with the potential spoilage of perishable air cargo resulting from a break in the “cool chain” is the additional vulnerability that such cargo can be tampered with, damaged, lost or even stolen. In this regard, many complications can and often do arise with respect to the transport of cargo to and from storage facilities to aircraft that, given the open nature by which perishable/high value cargo is transported, present numerous opportunities where such unfortunate events can occur. Indeed, the risk for perishable/high value cargo to become lost, damaged or stolen is exceptionally high at major airports that are very large and encounter heavy volumes of air traffic.
[0010] In fact, such vulnerability may even be deemed to pose a potential threat to safety and even national security. With respect to the former, it is well-known that the importation of numerous types of perishable cargo, and in particular agricultural products, can (or must) be inspected to insure that the same is not contaminated, whether by parasites, insects or any other type of contamination. In addition or, alternatively, the open nature by which air cargo is typically transported presents an opportunity that the same will go unchecked and thus exposes a vulnerability that the cargo can be detrimentally manipulated.
[0011] In view of the foregoing, Tofco Industries, Inc., Assignee of the present application, has developed a temperature controlled cargo transport dolly for use in transporting perishable/high value cargo to and from an aircraft. Exemplary of such apparatus is disclosed in U.S. Pat. No. 7,043,932, entitled Temperature Controlled Air Cargo Container Transport Dolly, the contents of which are expressly incorporated herein by reference. The temperature controlled cargo transport dolly includes a housing having an enclosure, and a temperature control unit attached to the housing and adapted to control the temperature within the enclosure.
[0012] Although the previously designed temperature controlled cargo transport dolly addressed many of the then-existing deficiencies associated with conventional transport containers or dollies by incorporating a temperature control unit into the dolly, there are certain limitations associated therewith. For instance, the dolly is generally operated at slow speeds to mitigate shock-related damage to the temperature control unit, as well as to the cargo being transported within the dolly. Along these lines, previous temperature controlled transport dollies typically do not include suspensions because a conventional suspension would result in a varying height of the dolly cargo deck, e.g., a heavier load would cause the deck to lower, while a lighter load would cause the deck to rise. In many instances, the dollies are used with loading docks that have a universal height requirement, such as around 20.5 inches in the air cargo industry. Thus, a dolly having a variable deck height would be difficult to use with a fixed, universal loading dock height.
[0013] Therefore, there is a substantial need in the art for temperature controlled cargo dolly having suspension capabilities, while at the same time being capable of maintaining a prescribed height of a dolly loading deck. Various aspects of the present disclosure address this particular need, as will be discussed in more detail below.
BRIEF SUMMARY
[0014] According to various aspects of the present disclosure, there is provided a cargo dolly having a suspension assembly incorporated therein, wherein the suspension assembly is adapted to maintain the dolly at a prescribed height relative to an underlying surface. Thus, as cargo is loaded onto the dolly, and subsequently unloaded from the dolly, the dolly will substantially remain at the same height, which facilitates use of the dolly with standardized loading docks, such as loading docks/K Loaders associated with aircraft.
[0015] According to one embodiment, the dolly includes a chassis, a tow bar coupled to the chassis, and a deck coupled to the chassis and having a deck surface spaced from a ground plane by a first distance. At least two front wheels are coupled to the chassis and are rotatable about respective front wheel axes, with the at least two front wheels being adapted to roll on the ground plane. At least two rear wheels are coupled to the chassis and are rotatable about respective rear wheel axes, with the at least two rear wheels being in spaced relation to the at least two front wheels and adapted to roll on the ground plane. At least two front suspension assemblies connect respective ones of the at least two front wheels to the chassis, with each front suspension assembly being adapted to enable movement of a corresponding front wheel axis relative to the chassis. At least two rear suspension assemblies connect respective ones of the at least two rear wheels to the chassis, each rear suspension assembly being adapted to enable movement a corresponding rear wheel axis relative to the chassis. A front leveler is operatively coupled to the at least two front suspension assemblies and is adapted to individually adjust the at least two front suspension assemblies for moving the corresponding front wheel axes relative to the chassis. A rear leveler is operatively coupled to the at least two rear suspension assemblies and is adapted to individually adjust the at least two rear suspension assemblies for moving the corresponding rear wheel axes relative to the chassis. The front leveler and the rear leveler are collectively configured to adjust the respective at least two front suspension assemblies and at least two rear suspension assemblies to maintain the deck and at a prescribed distance relative to the ground plane.
[0016] Each of the at least two front wheels may be capable of swiveling about respective swivel axes extending generally perpendicular to the ground plane. The front wheels may be capable of swiveling 360 degrees, and thus, may function as a caster under a respective front suspension assembly.
[0017] The front leveler and the rear leveler may be collectively configured to maintain the first distance between 18 and 23 inches. The front leveler and the rear leveler may be further collectively configured to adjust the respective at least two front suspension assemblies and at least two rear suspension assemblies to maintain the deck substantially parallel to the ground plane.
[0018] Each front leveler may include at least one inflatable body operatively coupled to a respective one of the at least two front suspension assemblies, with the at least one inflatable body being selectively transitional between an inflated configuration and an deflated configuration, wherein transition from the deflated configuration toward the inflated configuration enables the suspension to counteract an increased load applied on the suspension from the chassis. The air cargo transport dolly may further include a source of pressurized fluid fluidly connected to the at least one inflatable body.
[0019] Each front suspension assembly may include a first/upper arm adapted to pivot relative to the chassis, with a portion of the first arm residing in a first plane. A second/lower arm may be operatively coupled to the first arm, with the second arm being adapted to pivot relative to the chassis, and a portion of the second arm may reside in a second plane. The first and second planes may remain parallel to each other as the first and second arms pivot relative to the chassis. Each front suspension assembly further includes a rod pivotally coupled to the first/upper arm and the second/lower arm.
[0020] The air cargo transport dolly may further include a housing coupled to the chassis, with the housing and the deck being configured to collectively define an enclosure for storing cargo. The housing may include at least one door. A temperature control unit may be coupled to the housing and adapted to control a temperature within the enclosure.
[0021] According to another embodiment, there is provided method of transporting cargo. The method includes receiving cargo on a dolly having a deck including a deck surface spaced from a ground plane, a plurality of wheels adapted to roll on the ground plane, and a suspension assembly, with the plurality of wheels being coupled to the deck via the suspension assembly. The suspension assembly is adapted to impart a variable suspension force on the deck. The method includes adjusting the suspension force imparted on the deck from the suspension assembly so as to maintain the deck surface at a prescribed distance from the ground plane.
[0022] The suspension force may be increased as a weight associated with the cargo increases, and the suspension force may be decreased as the weight associated with the cargo decreases.
[0023] The suspension assembly may include an inflatable body, and the adjusting step may include adjusting a fluid pressure within the inflatable body to adjust the suspension force imparted on the deck. The suspension force may be increased by adding fluid to the inflatable body to increase the fluid pressure, and the suspension force may be decreased by exhausting fluid from the inflatable body.
[0024] The dolly may further include a housing coupled to the deck to define an enclosure, and the method may further include the step of monitoring a temperature within the enclosure. The method may also comprise adjusting the temperature within the enclosure to maintain the temperature within the enclosure within a prescribed temperature range.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which:
[0026] FIG. 1 is a rear upper perspective view of an air cargo dolly having a temperature control unit and an adjustable suspension assembly;
[0027] FIG. 2 is an upper perspective view of the air cargo dolly shown in FIG. 1 , with the wall panels removed therefrom to expose a structural support assembly;
[0028] FIG. 3 is a partial upper perspective view of a deck including a plurality of deck rollers and retractable pegs;
[0029] FIG. 4 is a partial upper perspective view of a forward portion of the dolly including a front suspension assembly and a corresponding support structure therefore;
[0030] FIG. 5 is a front upper perspective view of a front suspension assembly coupled to a pair of front wheels;
[0031] FIG. 6 is a rear upper perspective view of the front suspension assembly and front wheels shown in FIG. 5 ;
[0032] FIG. 7 is a side view of the front suspension assembly in a first position;
[0033] FIG. 8 is a side view of the front suspension assembly in a second position;
[0034] FIG. 9 is an upper perspective view of a front leveler operatively coupled to the front suspension assembly;
[0035] FIG. 10 is a schematic view of a pneumatic system used to control the front and rear suspension assemblies;
[0036] FIG. 11 is a lower perspective view of a rear portion of the dolly to depict a plurality of rear wheels and corresponding rear suspension assemblies;
[0037] FIG. 12 is an upper perspective view of a rear suspension assembly;
[0038] FIG. 13 is a side view of the rear suspension assembly in a first position;
[0039] FIG. 14 is a side view of the rear suspension assembly in a second position;
[0040] FIG. 15 is a side view of the front and rear suspension assemblies in their respective first positions; and
[0041] FIG. 16 is a side view of the front and rear suspension assemblies in their respective second positions.
DETAILED DESCRIPTION
[0042] Referring now to the drawings, wherein the showings are for purposes of illustrating a preferred embodiment of the present disclosure, and are not for purposes of limiting the same, there is depicted a dolly 10 specifically configured and adapted for transporting cargo to and from an airplane. The dolly 10 differs from conventional airport cargo dollies due to the inclusion of a suspension assembly adapted to maintain the dolly 10 at a desired loading/unloading level, while at the same time being capable of absorbing shock as the dolly 10 is transported from one location to another.
[0043] The dolly 10 includes a chassis 12 including a front chassis member 14 , an intermediate chassis member 16 , and a rear chassis member 18 spaced from one another and extending in generally parallel relation to each other. A pair of side chassis members 20 , 22 (see FIG. 11 ) are coupled to the front, intermediate and rear chassis members 14 , 16 , 18 and extend in generally opposed relation to each other. Each side chassis member 20 , 22 includes a forward section and a rearward section, with the forward section extending between the front and intermediate chassis members 14 , 16 and the rearward section extending between the intermediate and rear chassis members 16 , 18 . The chassis members may be formed from metal or other materials known in the art. The chassis 12 may additionally include additional chassis members to provide further structural support.
[0044] A tow bar 24 is attached to the front chassis member 14 and a hitch 25 may be coupled to the rear chassis member 18 . The tow bar 24 is coupled to the front chassis member 14 a connecting bracket 26 which allows the tow bar 24 to pivot relative to the chassis 12 . In particular, the tow bar 24 may be coupled to the connecting bracket 26 via journals or bearings which allow for pivotal motion of the tow bar 24 about a pivot axis 28 . The tow bar 24 includes a distal end portion 30 adapted to be connected to a towing vehicle, such as a towing tractor, as is commonly used at airports for towing trailers and dollies. For instance, the distal end portion 30 may include an opening adapted to receive a pin which connects the tow bar 24 to the towing vehicle.
[0045] A deck 32 is coupled to the chassis 12 , with the deck 32 being adapted to support cargo thereon. The deck 32 includes a deck plate 36 and a plurality of deck rollers 38 extending through the deck plate 36 . According to one embodiment, the deck plate 36 extends between the intermediate chassis member 16 and the rear chassis member 18 , with the front chassis member 14 being spaced forwardly from the deck plate 36 . Therefore, as cargo is placed on the deck 32 , the weight of the cargo will be placed between the intermediate chassis member 16 and the rear chassis member 18 , which provides room from the front suspension and enhances maneuverability of the dolly 10 , as will be described in more detail below.
[0046] Each roller 38 includes a roller ball located within a roller ball housing, with the roller ball being capable of rotating within the housing. Cargo may be slid onto the deck 32 on top of the roller balls to facilitate entry and removal of cargo to and from the dolly 10 . The top of the roller balls preferably reside within a common deck plane 40 (see FIG. 15 ), which is spaced above an underlying ground plane by a deck height H. Of course, other embodiments may not include rollers 38 , and instead, cargo may be placed directly on the deck plate 36 . In that case, the deck plate 36 resides within the deck plane 40 . In this regard, the term “deck plane” is being used broadly herein and is associated with the surface of the dolly 10 upon which cargo is placed when loaded onto the dolly 10 .
[0047] The dolly 10 may optionally be outfitted with one or more pegs 44 coupled to the deck plate 36 . Each peg 44 is located within a peg opening 46 formed in the deck plate 36 , and may be selectively transitional between a retracted position and an extended position. When the peg 44 is in the retracted position, a peg surface 48 is positioned flush with the deck plate 36 , or below the deck plate 36 , and thus, the peg 44 does not extend above the deck plate 36 . When the peg 44 is in the extended position, the peg surface 48 is located above the deck plate 36 . The pegs 44 may be placed in the retracted position when loading/unloading cargo, with the pegs 44 being transitioned to the extended position when cargo is located on the deck 32 to prevent the cargo from inadvertently sliding off the deck 32 . It is contemplated that the pegs 44 transition between the retracted and extended positions by pivoting relative to the deck plate 36 . In other words, the pegs 44 may be “flipped up” when transitioning from the retracted position to the extended position, and may be “flipped down” when transitioning from the extended position to the retracted position. However, it is understood that in other embodiments the pegs 44 may be spring-loaded pegs, with the pegs 44 being lockable in retracted position, and releasable therefrom by pressing down on the pegs 44 to unlock the pegs 44 to allow the spring-biasing force to transition the pegs 44 toward the extended position.
[0048] The dolly 10 further includes a housing 50 coupled to the chassis 12 . The housing 50 and the deck 32 collectively define an enclosure for receiving the cargo. According to one embodiment, the housing 50 includes a front wall 52 , a first side wall 54 , a second side wall 56 in generally opposed relation to the first side wall 54 , and a rear wall 58 in generally opposed relation to the front wall 52 . A ceiling or roof 60 may extend over the deck 32 and cover the enclosure. The walls 52 , 54 , 56 , 58 and ceiling 60 are shown in FIG. 1 , but have been removed from FIG. 2 to illustrate the internal support structure for the walls 52 , 54 , 56 , 58 and ceiling 60 . According to one embodiment, at least one of the walls, and preferably two of the walls have doors operatively coupled thereto. In the exemplary embodiment, the first side wall 54 includes a side opening which may be covered by a side door 62 and the rear wall 58 includes a rear opening which may be covered by a rear door 64 . Each door may be separately and individually transitioned between open and closed positions relative to the respective openings which the doors cover. The doors 62 , 64 may have a latch or lock which maintains the respective door in the closed position.
[0049] The walls of the housing 50 may be coupled to support members 66 , which are coupled to the chassis 12 . The support members 66 may include both vertical and horizontal support elements to provide adequate support to the housing 50 .
[0050] A temperature control unit 68 may be coupled to the housing 50 and adapted to control a temperature within the enclosure. In particular, the temperature control unit 68 may include an air conditioner for cooling the temperature within the enclosure, as well as a heater for heating the temperature within the enclosure. For instance, the cargo placed within the enclosure may include temperature-sensitive products, such as food or pharmaceuticals, which may be damaged if subjected to extreme temperatures, as is often the case when the dolly 10 sits on a tarmac. Thus, the temperature control unit 68 may be set to maintain a desired temperature within an acceptable temperature range (e.g., +/−2 degrees from the desired temperature). The housing 50 and deck 32 may be filled with insulation to mitigate heat transfer with the external environment through the housing and/or the deck 32 .
[0051] The dolly 10 includes a plurality of front wheels 70 and a plurality of rear wheels 72 coupled to the chassis 12 to facilitate movement of the dolly 10 and to support the weight of the cargo placed in the dolly 10 , with the front and rear wheels 70 , 72 being adapted to roll on the ground plane 42 . In the exemplary embodiment, the dolly 10 includes two pairs of front wheels 70 and three pair of rear wheels 72 . Each pair of front wheels 70 is rotatable about a respective front wheel axis 74 , and each pair of rear wheel 72 is rotatable about a respective rear wheel axis 76 to effectuate movement of the dolly 10 in a forward and rearward direction. Each pair of front wheels 70 is additionally capable of swiveling 360 degrees about a swivel axis 78 generally perpendicular to the ground plane 42 to enable steering of the dolly 10 . In this regard, each pair of front wheels 70 may function as a caster, enabling steering of the dolly 10 about a relatively small turning radius. The rear wheels 72 are not capable of swiveling.
[0052] Each pair of front wheels 70 is coupled to the chassis 12 via a respective front suspension assembly 80 , and each pair of rear wheels 72 is coupled to the chassis 12 via a respective rear suspension assembly 82 . The front and rear suspension assemblies 80 , 82 differ from each other, as will be described in more detail below.
[0053] Each front suspension assembly 80 is adapted to enable movement of a corresponding front wheel axis 74 relative to the chassis 12 along a suspension axis 84 , and also allows for swiveling of the front wheels 70 about the swivel axis 78 , which may be aligned with the suspension axis 84 . The ability of the front wheels 70 to swivel 360 degrees, while also being coupled to a front suspension arm provides a significant departure from conventional dolly wheels. FIGS. 5 and 6 are front and rear upper perspective views of a front suspension assembly 80 , which generally includes a first arm 86 , a second arm 88 , and a suspension rod 90 . Each front suspension assembly 80 is coupled to the chassis 12 via a front support frame 94 (see FIG. 4 ), which includes a pair of upper support members 96 and a front plate 98 . The upper support members 96 extend between the front plate 98 and the support member(s) 66 of the housing 50 . A brace 100 may extend between the upper support members 96 to provide stabilization therebetween as well as to provide shock absorber mounting. The front support frame 94 further includes a press-bracket 102 , which is positioned in generally opposed relation to a portion of the second arm 88 .
[0054] The first arm 86 of the front suspension assembly 80 includes a first end portion 104 pivotally coupled to the front support frame 94 , and a second end portion 106 pivotally coupled to the suspension rod 90 . In the exemplary embodiment, the first end portion 104 includes a pair of fingers, each being pivotally coupled to the front support frame 94 , while the second end portion 106 is pivotally coupled to diametrically opposed portions of the suspension rod 90 .
[0055] The second arm 88 includes a first end portion 108 pivotally coupled to the front support frame 94 and an aperture 110 through which the suspension rod 90 extends. The second arm 88 is pivotally coupled to the suspension rod 90 via a pivot bearing 112 . The second arm 88 further includes a press-plate 114 in generally opposed relation to the press-bracket 102 of the front support frame 94 .
[0056] The pivotal connection of the first and second arms 86 , 88 to the front support frame 94 allows the first and second arms 86 , 88 to also pivot relative to the chassis 12 . Furthermore, since the first pivot arm 86 and the second pivot arm 88 are also pivotally connected to the suspension rod 90 , the first pivot arm 86 remains generally parallel to the second pivot arm 88 as the arms 86 , 88 transition through their pivotal range of motion. Along these lines, a portion of the first arm 86 resides in a first plane, and a portion of the second arm 88 may reside in a second plane, with the first and second planes remaining substantially parallel to each other as the first and second arms 86 , 88 pivot relative to the chassis 12 .
[0057] The first and second pivot arms 86 , 88 are adapted to pivot relative to the chassis 12 to control the height of the deck 32 relative to the ground plane 42 . Referring now specifically to FIGS. 7 and 8 , the front suspension assembly 80 is shown in two different positions. In FIG. 7 , the front suspension assembly 80 is shown in a first position, with the press-bracket 102 of the front support frame 94 being spaced from the press-plate 114 of the second pivot arm 88 by a first suspension distance S 1 . In FIG. 8 , the front suspension assembly 80 is shown in a second position, with the press-bracket 102 of the front support frame 94 being spaced from the press-plate 114 of the second pivot arm 88 by a second suspension distance S 2 greater than the first suspension distance S 1 . In this respect, as the front suspension assembly 80 transitions from the first position to the second position, the front portion of the deck 32 may be raised relative to the ground plane 42 . Conversely, as the front suspension assembly 80 transitions from the second position to the first position, the front portion of the deck 32 may be lowered relative to the ground plane 42 .
[0058] According to one embodiment, the position of the front suspension assembly 80 is adjusted by a front leveler 116 , which includes an inflatable body 118 and a control valve 120 for inflating/exhausting the inflatable body 118 . In this respect, the control valve 120 is fluidly coupled to a source of pressurized fluid 122 (e.g., air), as well as being fluidly coupled to the inflatable body 118 . The inflatable body 118 is selectively transitional between an inflated configuration and a deflated configuration, wherein transition from the deflated configuration toward the inflated configuration enables the front suspension assembly 80 to apply an increased suspension force on the dolly chassis 12 to counteract an increased load applied on the front suspension assembly 80 from the chassis 12 .
[0059] The front leveler 116 further includes a control lever 126 , a linkage 128 , and a connector 130 . The control valve 120 is mounted to the front support frame 94 , while the connector 130 is mounted to the second pivot arm 88 . Pivotal movement of the second pivot arm 88 causes the control lever 126 to pivot relative to the control valve 120 , which in turn, opens or closes the control valve 120 to regulate the volume of the inflatable body 92 . Along these lines, the control valve 120 includes a supply port 132 which receives pressurized fluid from the pressurized fluid source 122 , a delivery port 134 which delivers pressurized fluid to the inflatable body 92 via delivery tube 135 , and an exhaust 136 which allows fluid from the inflatable body 92 to be exhausted to the ambient environment.
[0060] When the control lever 126 pivots to a first position corresponding to a low deck height H, the control valve 120 is opened to allow pressurized fluid from the pressurized fluid source 122 to flow to into the control valve 120 through the supply port 132 , and then exit the control valve 120 via the delivery port 134 for delivery to the inflatable body 118 . When the inflatable body 118 is inflated to a desired position, the control lever 126 will pivot to a second position associated with an acceptable deck height H, which closes the control valve 120 to prevent further inflation of the inflatable body 118 . When the control lever 126 pivots to a third position corresponding to a high deck height H, the exhaust valve is opened to allow fluid to be exhausted from the inflatable body 118 .
[0061] An exemplary control valve 120 is the Extreme Air™ height control valve from Ridewell Suspensions, although other control valves/mechanisms known in the art may also be used without departing from the spirit and scope of the present disclosure.
[0062] Turning now to the rear portion of the dolly 12 , and referring specifically to FIGS. 11-14 , each rear suspension assembly 82 is operatively coupled to a pair of rear wheels 72 and the chassis 12 , and includes a rear suspension arm 138 . The rear suspension arm 138 includes a rear suspension press-plate 142 , which is positioned in generally opposed relation to a rear chassis press-plate 144 coupled to the chassis 12 . A brake bar 140 extends under the deck 32 and is mounted to each rear suspension arm 138 . A multiple linkage assembly 145 may extend between the brake bar 140 and the rear suspension arm 138 . The brake bar 140 may be associated with a rear parking brake, which may be activated by the tow bar 24 . In particular, the brake bar 140 may be operatively coupled to the tow bar 24 , such that when the tow bar 24 is lifted upwardly from its normal towing position, a parking brake associated with the brake bar 140 may be activated.
[0063] A rear leveler 146 is operatively coupled to the rear suspension assemblies 82 and is adapted to individually adjust the rear suspension assemblies 82 for adjusting the position of the rear portion of the deck 32 . This is effectively achieved by adjusting the distance between the rear wheel axes 76 and the chassis 12 . The rear leveler 146 is similar to the front leveler 116 discussed above, and generally includes a control valve 148 , control lever 150 , a linkage 152 , and a connector 154 and an inflatable body 156 . Each control valve 148 is mounted to the chassis 12 via a mounting bracket, while the connector 154 is mounted to the rear suspension arm 138 . Pivotal movement of the rear suspension arm 138 causes the control lever 150 to pivot relative to the control valve 148 , which in turn, opens or closes the control valve 120 to regulate the volume of the inflatable body 156 . Along these lines, the control valve 120 includes a supply port which receives pressurized fluid from the pressurized fluid source 122 , a delivery port which delivers pressurized fluid to the inflatable body 156 via delivery tube, and an exhaust which allows fluid from the inflatable body 156 to be exhausted to the ambient environment.
[0064] When the control lever 150 pivots to a first position corresponding to a low deck height H, the control valve 148 is opened to allow pressurized fluid from the pressurized fluid source 122 to flow to into the control valve 148 through the supply port, and then exit the control valve 148 via the delivery port for delivery to the inflatable body 156 . When the inflatable body 156 is inflated to a desired position, the control lever 150 will pivot to a second position associated with an acceptable deck height H, which closes the control valve 148 to prevent further inflation of the inflatable body 156 . When the control lever 150 pivots to a third position corresponding to a high deck height H, the exhaust valve is opened to allow fluid to be exhausted from the inflatable body 156 .
[0065] Please note that some structure, including the rear leveler 146 , has been removed or modified from FIG. 14 to more clearly illustrate the position of the rear suspension arm 138 and the inflatable body 156 .
[0066] The front leveler 116 and the rear leveler 146 are collectively configured to adjust the front suspension assemblies 80 and the rear suspension assemblies 82 to maintain the deck 32 at a prescribed distance relative to the ground plane 42 . In this respect, it is understood that as cargo is loaded on the deck 32 , the deck height will decrease, thereby creating an offset between the loading dock and the dolly deck 32 , which makes subsequent loading of the dolly 32 difficult or unsafe. Therefore, the levelers 116 , 146 can adjust the deck height to maintain the deck height at the same height as the loading dock, and level with the loading dock. Thus, if cargo is loaded toward the back of the deck 32 , the rear suspension assemblies 82 may be adjusted more than the front suspension assemblies 80 . Since various implementations of the dolly 10 may be specifically configured for use in transporting cargo for loading on airplanes, it is known that many air cargo loading docks are universally set at between 18-23 inches, and more particularly 20.5 inches. Thus, the front leveler 116 and the rear leveler 146 may be collectively configured to maintain the deck height between 18-23 inches, and more specifically 20.5 inches. Furthermore, the front levelers 116 and the rear levelers 146 may be further collectively configured to adjust the respective front suspension assemblies 80 and rear suspension assemblies 82 to maintain the deck 32 substantially parallel to the ground plane 42 . Although the foregoing describes the deck height as being set to be maintained between 18-23 inches, it is understood that the dolly may be configured to set the deck height at other heights. Furthermore, the dolly may include an input device (e.g., joystick, keypad, etc.) to allow the user to set the deck height.
[0067] Referring now to FIG. 10 , there is shown an exemplary pneumatic system associated with the suspension described herein. In particular, a pressurized fluid source 122 (e.g., air tank) is fluidly coupled to the front and rear levelers 116 , 146 via a manifold 158 and hoses 160 . A compressor 162 is coupled to the pressurized fluid source 122 to refill the pressurized fluid source 122 with fluid and maintain the pressure therein at a prescribed pressure level. The pressurized fluid source 122 , air compressor 162 , and manifold 158 may be located within the dolly enclosure and separated from the main loading area of the deck by a bar 164 so as to prevent inadvertent contact between the cargo and the pressurized fluid source 122 .
[0068] With the basic structure of the dolly 10 described above, the following discussion will highlight an exemplary use of the dolly 10 for transporting cargo. The dolly 10 may be positioned next to a loading dock to receive cargo therefrom. The side door 62 and/or the rear door 64 may be used to load the cargo onto the dolly 10 . As the cargo is loaded on the dolly 10 , the cargo is received on the deck 32 . The suspension assembly (e.g., the front and rear suspension assemblies 80 , 82 ) is adapted to impart a variable suspension force on the deck 32 . Such suspension force is adjusted so as to maintain the deck surface at a prescribed distance from the ground plane. In particular, the suspension force is increased as a weight associated with the cargo increases, as may be the case when cargo is loaded onto the dolly 10 , and the suspension force is decreased as the weight associated with the cargo decreases, as may be the case when cargo is unloaded from the dolly 10 .
[0069] The suspension force is adjusted by adjusting a fluid pressure within one or more of the inflatable bodies 118 , 156 associated with the front and rear suspension assemblies 80 , 82 to adjust the suspension force imparted on the deck 32 . The suspension force may be selectively increased by adding fluid to the inflatable bodies 118 , 156 to increase the fluid pressure, and the suspension force may be selectively decreased by exhausting fluid from the inflatable bodies 118 , 156 .
[0070] While the cargo is located within the dolly 10 , the temperature within the enclosure may be monitored and adjusted to maintain the temperature within the enclosure within a prescribed temperature range.
[0071] The inclusion of the suspension on the dolly 10 may allow the dolly 10 to be transported between an airplane and a loading dock at a speed that is greater than conventional temperature controlled dollies. In particular, the suspension assembly absorbs shock loads/vibrations generated as the dolly travels over uneven terrain at higher speeds, which in turn protects delicate components associated with the temperature control unit 68 , as well as the cargo located within the dolly 10 . In this regard, the dolly 10 may be particularly suitable for carrying berries or other shock sensitive products, which require transport in a temperature controlled environment, and which may bruise if subject to large vibrations.
[0072] Although the exemplary embodiment shows the dolly specifically configured and adapted for use in transporting cargo to and from an airplane, it is understood that other embodiments of the dolly may be configured for other uses. For instance, the dolly may be used to transport high value items, such as money/currency. The dolly may also be used as a quarantine or as a freezer to freeze bugs or undesirable cargo to destroy it if it is so needed.
[0073] The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the disclosure disclosed herein, including various ways of implementing a suspension on a cargo dolly. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.
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A cargo dolly having a suspension assembly incorporated therein, wherein the suspension assembly is adapted to maintain the dolly at a prescribed height relative to an underlying surface. Thus, as cargo is loaded onto the dolly, and subsequently unloaded from the dolly, the dolly will substantially remain at the same height, which facilitates use of the dolly with standardized loading docks, such as loading docks associated with aircraft.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 10/859,962 filed on Jun. 4, 2004 and entitled “Variable Laminoplasty Implant,” which is hereby incorporated by reference in its entirety.
FIELD
The present application relates to an implant for bone surgery, and more specifically to a vertebral implant with an adjustable configuration.
BACKGROUND
In certain pathologies, the spinal canal extending through a patient's vertebrae is or becomes too narrow and constricts the spinal cord extending therethrough. The narrowing may be congenital, potentially affecting patients at any age. Narrowing can also be attributable to other causes, such as age, injury or removal of a spinal disk.
A condition associated with aging, for instance, is spondylolsis, in which intervertebral disc loose water and become less dense. These degenerative changes near the disk can cause an overgrowth of the bone, producing bony spurs called, “osteophytes” that can compress the spinal cord. The constriction of the spinal cord in the cervical spine, for example, often produces pain, weakness, or loss of feeling in extremities. Other causes for narrowing of the spinal canal include disc shrinkage, which causes the disc space to narrow and the annulus to bulge and mushroom out, resulting in pressure on the spinal cord. Degenerative arthritis of facet joints can cause joints to enlarge, or the vertebra to slip with respect to each other, also compressing the spinal cord. Instability between vertebra, such as caused by stretched and thickened ligaments' can also produce pressure on the spinal cord and nerve roots.
Myelopathy, or malfunction of the spinal cord, occurs due to its compression. The rubbing of the spine against the cord can also contribute to this condition, and the spinal cord compression can ultimately compromise the blood vessels feeding the spinal core, further aggravating they myelopathy.
Traditional procedures for decompressing the spinal cord include a laminectomy, in which the lamina and spinal processes are removed to expose the dura covering the spinal cord. Another known procedure is a laminoplasty, in which the lamina is lifted off the dura, but not completely removed. Typically, one side of the lamina is cut, while a partial cut is made on the other side to hinge the lamina away from the spinal cord to increase the size of the spinal canal. A laminoplasty plate is then screwed to a facet and to the hinged open lamina. The plate of an appropriate size is selected and bent to the desired shape and preferably has a plurality of screw holes. A strut of bone can be placed in the open portion within the lamina and the facet to help hold the open position of the lamina. Prior to the operation, the surgeon needs to measure the vertebra to determine the size of the plate necessary for implantation. At that point, a plate can be selected with the appropriate dimensions, and implanted at the site.
A laminoplasty implant is needed that preferably allows its size to be varied prior to implantation, preferably without changing its overall shape or configuration, so that a plate does not have to be custom selected and intensively shaped and formed prior to each surgery.
SUMMARY
The present invention relates to a bone implant, and more preferably a vertebral implant. The implant has first and second bases configured for securing two first and second cut portions, respectively, of a vertebra. A connecting member is configured for associating the first and second bases at a pre-selected spacing from each other. Most preferably, the implant is adjustable to select and set the spacing. In the preferred embodiment, the implant is a laminoplasty implant, and the first and second vertebral portions are a lateral mass, its articular mass, or its facet, or a portion of the lamina, and the second vertebral portion can comprise, for example, at least part of the lamina.
The first base is preferably in fixed association with the connecting member. One of the connecting members and second base comprises an adjustable member that is adjustable to select the spacing between the bases. The other of these portions of the implant can include a linking member that is associable with the adjustable member. The adjustable member preferably adjusts the length of the connecting member measured from the first base to a connection location at which the linking member is associated with the adjustable member. This length is preferably adjusted without changing the overall shape or configuration of the implant and preferably by changing the length of the connecting member without modifying the general shape of the bases or the size of the position of he bases in contact with the bone when implanted.
Also, the adjustable member can define a plurality of mating portions, with the linking member being associable selectively with at least one of the mating portions to select the connection location. The mating portions and linking member are preferably configured for pivotally associating the adjustable member and second base. The mating portions and linking member of the preferred embodiment are configured to be placed into the association at a first pivotal orientation with respect to each other, and for connecting the first and second bases secured to the cup portions in a second pivotal orientation between the linking member and mating portions or connecting member.
In one embodiment, the mating portions and/or linking member comprise at least one or more protrusions receivable in one or more notches of the other of these elements to associate the adjustable and linking members a protrusion can be selectively receivable in at least one of the notches for selecting the connection location. At least one of the notches and protrusions is preferably arcuate about axial direction measured with respect to the spinal column, such that the protrusion is received for sliding in the notch and in this manner pivoting of the connecting member with respect to the linking member without sliding in the notch can be restricted if desired. A loading opening can be provided, for example, between a pair of the protrusions to receive the notches of the adjustable member therein for associating the adjustable member and the linking member. The adjustable portion is preferably configured for severing a potion of the connecting member disposed beyond the selected connection location from the first base.
At least one of the bases can include a concave contacting surface that is configured for receiving the cut portions of the vertebra. At least one of the bases preferably includes a fastener mount portion configured to attach a bone fastener thereto to secure the base to the vertebra. The fastener mount portion can include a plurality of fastener mount portions that are disposed at different axial locations with respect to the spinal access. This allows attaching bone fasteners depending on the axial spacing between the first and second cut portions. A fastener can be mounted in the fastener mount portions, and in one embodiment the fastener is articularble and includes a universally pivotal head. The head is associable with a vertebra joining member, such as a rod and at least one other vertebra in the spinal column. A further fastener mount potion can be provided, such as in the connecting member, for securing a bone graft thereto. Once the first and second bases are secured to the first and second cut portions of the vertebra, the connecting member preferably fixes the association between the bases, thus fixing the distance therebetween and holding the lamina in a desired hinged position. In a preferred embodiment of an articularble fastener, the fastener has a bone fastener portion configured for fastening to a bone, a head configured for associating with the vertebra joining member, and a universal joint that pivotally associates the fastener portion with the head for relative universal pivoting therebetween. In one embodiment, a passage is cooperatively defined by the head and joint to permit access to the fastener portion to engage it directly with the driver. Thus, a driver can be used to screw the fastener portion into the bone prior to attaching to a rod, or other vertebrae joining member.
Consequently, an improved implant is provided that can be used in a laminoplasty procedure without requiring the intensive customization of a bone plate or the selection from a wide size variety of bone plates prior to implantation. Preferably the implants can be customized in situ to best fit the patients anatomy substantially reducing the amount of time and costs to perform the operation.
BRIEF DESCRIPTION OF THE DRAWINGS
Various exemplary embodiments disclosed herein will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIGS. 1 and 2 are perspective views of a laminoplasty implant constructed according to a preferred embodiment of the invention, adjusted to different lengths;
FIGS. 3 and 4 are perspective views of alternative embodiments of implants with different fastener mount portions;
FIGS. 5 and 6 are a bottom view and a perspective rear view of another embodiment of an implant;
FIGS. 7 and 8 are a perspective and axial view of an implant fixed with other vertebrae;
FIGS. 9 and 10 are cross-sectional views of other embodiments of inventive universally pivotable screws; and
FIG. 11 is a perspective view of another embodiment of an articulated fastener.
DETAILED DESCRIPTION
Referring to FIG. 1 , in a preferred laminoplasty procedure, an osteotomy is performed in which a complete cut is made through vertebra 16 , approximately between the lamina 20 and lateral mass 14 , such as the articular mass or facet portion therof. A partial-depth cut 11 is made on the opposite lateral side, also approximately between the lamina 20 and other lateral mass 14 . The lamina 20 is then hinged open about the partial cut 11 to increase the cross-sectional size of the spinal canal to decompress the spinal cord therein.
A preferred embodiment of a laminoplasty implant 10 includes a lateral base 12 that is configured for securing to a lateral mass 14 of a vertebra 16 . A lamina base 18 is configured for securing to a portion of a lamina 20 that has been cut and hinged away from the lateral mass 14 . For alternative surgical procedures, the base can be configured for securing to different parts of the vertebra, a differently prepared vertebra, or to different bones, as desired.
Preferably, one or both bases 12 , 18 have concave contacting surfaces 22 , 24 that are configured for receiving the cut portions of the vertebra 16 , such as at the lateral mass 14 and lamina 20 . The lateral base 12 of the embodiment shown has an outside portion 26 that is preferably placed against the posterior surface of the lateral mass 14 outside the spinal canal 30 , and against an inside portion 28 that is preferably placed against a wall of the vertebrae at an angle to the position facet surface at the cut 32 location, preferably in the interior of the spinal canal 30 . Together, the outside and inside portions 26 , 28 of the lateral base 12 define the concave surface 22 for receiving and capturing the cut portion of the lateral facet 14 . The individual surfaces of the outside and inside portions 26 , 28 can also be concave, preferably by a slight amount.
In the embodiment shown, the angle between the outside and inside potions 26 , 28 at the concave surface is about a right angle, but can be varied depending on the location of the implantation and the angle of the cut that is made. Preferably, the angle is between about 30.degree. and 150.degree., and more preferably between about 60.degree. and 100.degree. In one embodiment, the angle can be up to about 180.degree., such as by employing an intermediate portion to connect the outside and inside portions. The inside portion 28 can be constructed as a lip to capture the edge of the lateral mass 14 at the cut, to assist in the proper placement of the implant 10 and prevent or restrict movement thereof after implantaion.
The lamina base 18 also preferably has an outside portion 34 , which is preferably placed against the posterior surface of the lamina 20 outside the spinal canal 30 . An intermediate portion 36 is configured and disposed for placement against a narrow edge of the lamina 20 , and an inside portion 38 is placed against an anterior surface of the lamina 20 inside the spinal canal 30 . Together, the outside, intermediate, and inside portions 34 , 36 , 38 of the lamina base 18 define the concave surface 24 for receiving and capturing the cut portion of the lamina 20 , preferably surrounding the cut portion of the lamina 20 . The inside portion 38 can be configured as a lip to help prevent pivoting of the lamina 20 tending to close the spinal canal 30 prior to the bone healing.
The angle between the outside and intermediate portions 34 , 36 in the preferred embodiment and between the intermediate and inside potions 36 , 38 at the concave surface are about right angles, but can be varied depending on the location of the implantation and the angle of the cut that is made. In one embodiment, only two angled portions are used, such as by providing a lip to capture the edge of the cut lamina, as is shown for the lateral base 12 . The angle between the outside and inside portions is preferably about 180.degree., but can alternatively be as low as about 30.degree., more preferably as low as about 60.degree., and most preferably as low as about 90.degree. The concave surface 24 captures the edge of the lamina 20 at the cut, to assist in the proper placement of the implant 10 .
The bases 14 , 18 preferably include fastener mount portions 40 configured for attaching a bone fastener thereto. If bone screws 42 are to be used, then the fastener mount portions can define suitable openings for receiving and fastening the bone screws 42 . The fastener mount portions 40 are preferably disposed for accessing and inserting the fasteners 42 from the outside of the bone, to facilitate implantation.
The lateral base 12 shown has two fastener mount portions 40 aligned laterally with respect to each other. The lamina base 18 shown, on the other hand, has two fastener mount portions 40 disposed axially with respect to each other. The position of the fastener mount portions 40 can be varied according to the bone available at the implantation site. For instance, the implant 44 of FIG. 3 has facet and lamina bases 46 , 48 , each with a fastener mount portion 50 , 52 configured to attach a single bone screw 42 . The implant 54 of FIG. 4 , however, has a lamina base 56 with fastener mount portions 58 configured for receiving and attaching up to three bone screws 42 . Alternative bases can secure to other numbers of fasteners in other arrangements. Similar fastener mount portion arrangements can be used for the lateral base.
The fastener mount portions of implant 54 , shown in FIG. 4 , has three fastener mount portions 58 oriented generally along the apices of a triangle. Two of the fastener mount portions 58 are disposed generally at a same lateral location, and at least two of the three are preferably disposed at different axial locations along the spinal axis when implanted. Since the vertebral laminae are displaced downwardly in an axial direction with respect to the facets of the same vertebrae, axially displaced fastener mount portions, such as in lamina base 56 in FIG. 4 and lamina base 18 in FIG. 1 , can help ensure that at least one or more of the fastener mount portion 40 , 58 is disposed over bone into which a fastener can be placed.
As shown in FIG. 4 , the upper fastener mount portion 58 is empty, as it is not completely over lamina bone. On the other hand, the other two fastener mount portions 58 are fully disposed over bone, and each has a bone screw 42 secured therethrough. The leftmost fastener mount portion 58 , disposed closest to the lateral base 12 , is preferably disposed axially between the other two fastener mount portions 58 in a position likely to always be able to engage the bone with a fastener. If the implant 54 were used on the right side of a vertebra, instead of on the left side as shown, the other of the two fastener mount portions 58 that are is a close axial position would be over bone and used for securing a fastener, while the fastener mount portion that is shown with a bone screw 42 in FIG. 4 would be empty. In an alternative embodiment, the triangle may be reversed, with a pair of fastener mount portions provided towards the lateral base, and a single fastener mount portion provided further therefrom than the other two. An alternative embodiment has an asymmetrical arrangement of fastener mount portions, and one embodiment has two positioned along a line that is diagonal to the lateral direction between the facet and lamina bases.
Referring again to FIG. 1 , implant 10 has a connecting member 60 that associated the facet and lamina bases 12 , 18 at a preselected spacing 62 from each other. The spacing 62 is selected to determine the hinged position in which the cut lamina will be maintained when the surgery is complete. The connecting member 60 preferably acts as a strut holding the bases 12 , 18 apart.
The preferred connecting member 60 and/or its association with at least one of the bases 12 , 18 is adjustable for selecting the desired spacing 62 . In the preferred embodiment, one of the bases 12 , 18 , preferably the lateral base 12 , is in fixed association, and preferably integral with or of unitary construction with the connecting member 60 . The other base, preferably the lamina base 18 , has a linking member 64 that is associable with the connecting member 60 . The preferred linking member 64 has at least one protrusion, such as parallel D-rings, that is associable with any of a plurality of notches 66 defined between ledges 68 on the connecting member 60 to select a location for the connection between a notch 66 and the D-ring.
Prior completing the implantation, such as after the lamina base 18 is secured to the cut lamina 20 but before the lateral base 12 is secured to the lateral mass 14 , at least one of the ledges 68 of the connecting member 60 is inserted into a loading opening, such as a slot 70 defined in the linking member 64 and extending into the facing D-rings, which slot 70 preferably has a larger cross-section than the cross-section of the ledges 68 along a plane parallel to the notches 66 .
Once a ledge 68 is placed within the slot 70 , the mated connecting member 60 and linking member 64 are pivotally associated, and the connecting member 60 can be pivoted about an axis that is preferably generally parallel to the spinal axis to place the lateral base 12 against the vertebra lateral mass 14 , where it can be secured. When both bases 12 , 18 are engaged with each other and secured to the respective bone portions, the connecting member 60 preferably maintains the bases 12 , 18 in fixed association with each other, preferably substantially preventing movement between the bases 12 , 18 .
The connecting member 60 is adjustable in length, and preferably comprises an adjustable member 72 , which includes the notched 66 and ledges 68 . The adjustable member 72 is adjustable to adjust a length of the connecting member 60 and thus the spacing 62 . By selecting the notch 66 to be mated with the linking member 64 D-rings, the length of the connecting member 60 can be incrementally adjusted. Once the anatomy of the vertebra is measured and preferably verified by mating the connecting member 60 with the lamina base 14 and pivoting the connecting member 60 and lateral base 12 portion to contact the lateral mass 14 , the connecting member 60 can be separated from the lamina base 18 . The adjustable member 72 of the connecting member 60 can then be clipped on the opposite side of the desired notch 66 from the lateral base 12 to shorten the connecting member 60 and eliminate unneeded material. FIG. 2 shows an implantation of the implant 10 with the connecting member adjusted and clipped to a shorter length than in FIG. 1 , thus fixing the lamina 20 at a smaller open hinged angle than in FIG. 1 . The shorter arrangement of FIG. 2 can also be used for smaller vertebrae.
Referring to FIGS. 5 and 6 , another implant 74 embodiment is shown with a fastener mount portion 76 , which is preferably associated with connecting member 78 and faces the spinal canal 30 . Fastener mount portion 76 is preferably positioned and configured for securing a bone graft fragment 80 to help support the hinged lamina 20 in the open position, and ultimately for fusing with the vertebral bone when the vertebra heals. A fastener, such as a bone screw 84 is fastened through the fastener mount portion 76 to the one fragment 80 .
In the embodiment shown, the connecting member 78 is substantially straight. Alternatively, the connecting member can be curved, preferably bowed outwardly from the spinal canal to increase its expanded cross-sectional size.
The bone fragment 80 is shaped to preferably contact both sides of the cut 32 in the vertebra 16 . The bone fragment 80 is preferably also provided with a notch 86 to receive the inside portion 28 of lateral base 82 to extend around the cut portion of the lateral mass 14 . Although a similar notch can be provided for the lamina base 88 , the lamina base 88 of this embodiment does not have a third portion that extends inside the spinal canal 30 . As shown in FIG. 5 , the ledges are arcuately curved about an axial direction with respect to the spinal column, preferably following the curved shape of the D-rings of linking member 64 and further controlling the relative orientation between the connecting member 78 and the linking portion 64 .
As shown in FIG. 7 , an implant embodiment 90 has a lateral base 46 that is secured to lateral mass 14 by an articulated bone fastener 92 , which is itself secured to at least one adjacent vertebra 16 . Fastener 92 comprises a fastener portion 94 , which is preferably a bone screw portion fastened to the vertebra 16 , and a head 96 that is configured for associating with a vertebra joining member, such as a rod 98 . A locking mechanism, such as a set screw 102 , preferably locks the rod 98 to the head 96 . A joint 100 , which is preferably substantially universally pivotable and also preferably rotatably, pivotally associates the head 96 with the fastener portion 94 .
As shown in FIG. 8 , an embodiment of the joint 100 includes a link 104 configured with two spherical portions 106 , 108 , preferably of different sizes. Each spherical portion 106 , 108 is received in a socket 110 of the head 96 or the fastener portion 94 . The sockets 110 preferably extend more than half way around the spherical portions 106 , 108 to retain the spherical portions 106108 therein. A double ball and socket joint is thus provided, preferably allowing rotation, and most preferably unlimited rotation, at least about the axis of the head 96 or fastener portion 94 . Pivoting is preferably allowed through an arc of between about 10.degree. and 80.degree., and more preferably between about 20.degree. and 70.degree., preferably in any direction about the spherical portions 106 , 108 .
A passage 120 is preferably defined cooperatively by aligned openings in the head 96 and joint 100 configured to receive a driver, such as a screw driver, to engage directly with the fastener portion 49 to secure it to the bone. The passage 120 , preferably is aligned with a driver receptacle 122 in the fastener portion 94 .
The articulated fasteners 92 thus allow other vertebrae to support each other and can be useful where vertebrae are to be fused. As shown in FIG. 7 , a similar arrangement of articulated fasteners 92 and rods 98 can also be employed on the opposite facets 14 to improve support and possibly fixation with other vertebrae.
Another embodiment of a pivoted fastener 112 is shown in FIG. 9 , in which a double ball and socket joint 114 includes a link 116 with two spherical portions 118 associated with head 124 and fastener portion 94 . The joint 128 articulated fastener 126 of FIG. 10 includes a double-socket member 130 that receives spherical portions 132 , 134 , which are respectively integral or unitary with the head 136 and fastener portion 138 . The articulated fastener 140 of FIG. 11 has a joint 142 with a link 144 that has a cylindrical portion 146 associated with a spherical portion 148 , which are received in complementary sockets 150 , 152 in head 156 and fastener portion 158 , respectively. Although the spherical portion 148 can rotate about an axis joining the fastener portion 158 and head 156 , the cylindrical portion 146 is restricted against such rotation.
Referring again to FIG. 8 , a unitary facet-base/connecting-member portion has the connecting member 160 offset from the interior edge of the lateral base 46 , which is disposed closest to the spinal canal 30 , by an offset amount 164 , measured laterally in this embodiment. This offset 146 is preferably of similar or greater thickness as the thickness of the bone graft 80 . In an alternative embodiment, greater or lesser offsets can be provided, including substantially no offset at all. In embodiments without a bone graft, the offset 154 can provide additional room for the expanding spinal cord. Also, the connecting member preferably extends at an angle of between about 100.degree. and 140.degree. from the lateral base.
The preferred materials for use in the embodiments of the implants of the present invention include titanium, PEEK (polyetheretherketone) and absorbable materials such as a polylactic or polyglycolic acid material. Other suitable materials may alternatively be used. The preferred spacing 62 provided by the connecting member 60 is between about 5 mm and 30 mm, depending on the location in the spine in which it is desired to be employed. For example, cervical implants will typically be between about 10 mm and 20 mm, while lumbar implants will typically be between about 20 mm and 30 mm. The bone screw diameters can also vary according to the size of the implant and the implant location, and typically vary between about 3 mm and 6 mm, with a length of about 8 mm to 20 mm.
While illustrative embodiments of the invention are disclosed herein, it will be appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments that come within the spirit and scope of the present invention
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A vertebral implant comprising a first base configured for securing to a first cut portion of a vertebra, and second base configured for securing to a second cut portion of the vertebra. A connecting member is configured to associate the first and second bases at a preselected spacing from each other, and the implant is preferable adjustable to select the spacing.
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TECHNICAL FIELD
[0001] This invention relates to compositions and methods for therapeutic or prophylactic treatment of chronic kidney disease. In particular this invention concerns compositions comprising VIP or certain active fragments of VIP and their use in the treatment of chronic kidney disease, kidney fibrosis or kidney failure.
BACKGROUND
[0002] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
[0003] Chronic kidney disease (CKD) affects approximately 10% of the general population in the western world. Data from the UK and the US indicate that while the incidence of CKD is approximately 2% of the young adult population, it rises markedly with age reaching an incidence of 50% in the population aged over 75 years. These figures will increase as a consequence of the ageing of western populations and secondly from the increase in Type II diabetes flowing from the obesity epidemic. Most patients with Type II diabetes have evidence of renal damage, such as microalbuminuria, at the time of the diagnosis of their diabetes, and so an increase in the incidence of diabetes will automatically increase the incidence of early stage CKD. It will probably also increase the incidence of later stage CKD. A little over a decade ago diabetes ranked 3 rd or 4 th as a cause for entry into renal replacement therapy programmes (dialysis and/or transplantation). While other causes have remained static or have increased only slightly, diabetes has increased to being the most common reason for entry into end stage renal failure programmes in less than a decade.
[0004] In CKD the progressive loss of renal function occurs as a consequence of the deposition of fibrous tissue between the functional units of the kidney or nephrons (interstitial fibrosis) as well as the ongoing replacement of the filtration surface by fibrous tissue (glomerular sclerosis). Some studies indicate that the former (interstitial fibrosis) may be more important than the latter (glomerular sclerosis) in determining whether a patient progresses to end stage. While primary glomerular damage is also important in the development of CKD and end stage renal disease (ESRD) there is evidence that increased interstitial fibrosis accelerates the loss of glomerular function by causing ischaemic damage to glomeruli—through collapsing the tufts and thickened capsules leading to obsolescence. Through this mechanism, interstitial fibrosis accelerates the progression of renal disease to end stage. Currently available treatments (such as ACE inhibitors, angiotensin receptor blockers, rennin inhibitors) alter glomerular haemodynamics reducing intraglomerular pressure thereby acting to stabilise glomerular sclerosis. In general they slow but do not prevent the progression of CKD. With an increasing prevalence of CKD clearly there is a substantial need to reduce the need for renal replacement therapy by preventing and/or reversing renal fibrosis.
[0005] VIP was discovered by Said and Mutt in the 1970's and has been shown to affect urinary sodium and bicarbonate excretion by the kidney. Systemic VIP administration also increases renin secretion by the kidney, which may be pro-fibrotic as renin has recently been shown to have pro-inflammatory and pro-fibrotic properties. Acute VIP administration decreases glomerular filtration rate and renal plasma flow but the effects of chronic administration are not known. VIP administered prior to the insult has been shown to protect against acute renal failure, which occurs due to haemorrhage. However, the mechanisms involved in hypovolaemic acute renal failure (low perfusion pressure and hypoxia) are not contributory to the progression of CKD. Agents which lower blood pressure have been shown to slow the progression of chronic kidney disease by reducing intraglomerular pressure and thus decreasing the progression of glomerular sclerosis. VIP is a potent vasodilator, however unaided VIP does not lower blood pressure in the whole animal.
[0006] Conventional view of structure/function relationship with respect to VIP activity is that the N-terminal amino acid residues (1-5) are important and necessary for signal delivery once VIP binds to its receptor. Further, there are certain key amino acid residues throughout the VIP molecule, distal to the N-terminus, that are important for receptor binding. This would suggest that fragments of VIP lacking either the N-terminal residues or significant portions that encompass the receptor binding residues would not be fully functional.
[0007] Activity of VIP or fragments of VIP in the treatment of conditions such as kidney fibrosis, chronic kidney disease or kidney failure, has not been previously reported. Need currently exists for better and/or alternative treatments for such conditions.
[0008] It is therefore an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.
SUMMARY OF THE INVENTION
[0009] The present invention is based in part on the observation that VIP and/or VIP fragments have the ability to prevent the development, or reverse established fibrosis in the kidney. Despite the currently prevailing view, the activity of VIP and its fragments in the treatment and/or prevention of chronic kidney disease and fibrosis is not curtailed by either deletion of the N-terminal residues of VIP or the majority of amino acid residues responsible for receptor binding.
[0010] According to a first aspect, the invention provides a composition for the prophylactic or therapeutic treatment of chronic kidney disease, the composition comprising a pharmaceutically effective amount of vasoactive intestinal peptide (VIP) or one or more functional VIP fragments selected from VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24) or conservative substitutions thereof. Preferably, the associated condition is kidney fibrosis.
[0011] According to a second aspect, the invention provides a composition for the prophylactic or therapeutic treatment of kidney failure, the composition comprising a pharmaceutically effective amount of vasoactive intestinal peptide (VIP) or one or more functional VIP fragments selected from VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24) or conservative substitutions thereof.
[0012] According to a third aspect, the invention provides a composition for the prophylactic or therapeutic treatment of kidney fibrosis, the composition comprising a pharmaceutically effective amount of vasoactive intestinal peptide (VIP) or one or more functional VIP fragments selected from VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24) or conservative substitutions thereof.
[0013] Preferably, the compositions according to the present invention are administered in conjunction with a pharmaceutically acceptable carrier, which may be any of those known in the art or devised hereafter and suitable for the intended use. As well as carriers, the pharmaceutical composition of the invention may include other ingredients, including dyes, preservatives, buffers and anti-oxidants, for example. They may preferably be administered in conjunction with one or more other active agents useful in the treatment of kidney conditions. They may, for preference, be formulated for administration by oral, intravenous, intramuscular or subcuticular routes. Other methods of administration such as patches, snuffs, nasal sprays and the like, will be clear to those skilled in the art.
[0014] The pharmaceutically effective amount of VIP or an active VIP fragment will vary according to the patient's general condition and/or the exact nature and severity of the disease. These variables can be ascertained by one skilled in the art based on experience and with routine experimentation only. An appropriate dosage range, as a starting point, can be derived from dosages administered in the animal models described herein, or with reference to PCT/AU2005/000835. The compositions of the invention may be used to prevent or slow down progression of established kidney disease or condition, particularly fibrosis, as well as to reduce the degree of, or prevent establishment of fibrosis.
[0015] According to a fourth aspect, the invention provides a method of prophylactic or therapeutic treatment of chronic kidney disease in a subject, the method comprising administering to the subject at risk of developing chronic kidney disease, or to a subject having chronic kidney disease, a composition comprising a pharmaceutically effective amount of vasoactive intestinal peptide (VIP) or one or more functional VIP fragments selected from VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24) or conservative substitutions thereof.
[0016] With respect to prophylactic treatment it will be understood that such a treatment would benefit particularly subjects who are at risk of developing chronic kidney disease and/or kidney fibrosis. As an example of subjects in the risk category are those having associated conditions such as hypertension, diabetes, glomerulonephritis, heavy metal poisoning, gout, drugs such as cis-platinum and others which are used in cancer chemotherapy, as well as gold and penicillamine which are used in treatment of rheumatoid arthritis, genetic predisposition, other conditions such as reflux nephritis, SLE and vasculitis, and the like.
[0017] The prophylactic treatment may be used to prevent or slow down the development of fibrosis in a subject having fibrosis or at risk of developing fibrosis.
[0018] According to a fifth aspect, the invention provides a method of prophylactic or therapeutic treatment of kidney failure in a subject, the method comprising administering to the subject at risk of developing kidney failure, or to a subject having kidney failure a composition comprising a pharmaceutically effective amount of vasoactive intestinal peptide (VIP) or one or more functional VIP fragments selected from VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24) or conservative substitutions thereof.
[0019] According to a sixth aspect, the invention provides a method of prophylactic or therapeutic treatment of kidney fibrosis in a subject, the method comprising administering to the subject at risk of developing kidney fibrosis, or to a subject having kidney fibrosis, a composition comprising a pharmaceutically effective amount of vasoactive intestinal peptide (VIP) or one or more functional VIP fragments selected from VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24) or conservative substitutions thereof.
[0020] The prophylactic treatment may be used effectively to prevent or slow down the progression of established chronic kidney disease, in particular established fibrosis, in a subject or it may be used to prevent the development of fibrosis in a subject at risk of developing fibrosis.
[0021] Conditions that are associated with, or predispose a subject to, the development of kidney fibrosis include those which give rise to generation of profibrotic mediators.
[0022] It will be apparent to one skilled in the art that the pattern of use of the compositions of the invention and the dosage regimen may need to be altered for optimum effect. It may be necessary to take into account the nature of the disease or condition as well as its severity.
[0023] According to a seventh aspect, the invention provides vasoactive intestinal peptide (VIP) or one or more functional VIP fragments selected from VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24) or conservative substitutions thereof, for use in the prophylactic or therapeutic treatment of chronic kidney disease.
[0024] According to an eighth aspect, the invention provides vasoactive intestinal peptide (VIP) or one or more functional VIP fragments selected from VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24) or conservative substitutions thereof, for use in the prophylactic or therapeutic treatment of kidney failure.
[0025] According to a ninth aspect, the invention provides vasoactive intestinal peptide (VIP) or one or more functional VIP fragments selected from VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24) or conservative substitutions thereof, for use in the therapeutic or prophylactic treatment of kidney fibrosis.
[0026] Preferably, the use is to prevent or slow down progression of established chronic kidney disease. Alternatively, the use is to prevent or slow down the development of fibrosis in a subject at risk of developing fibrosis. The use is also for reducing the degree of established fibrosis.
[0027] According to a tenth aspect, the invention provides a method of reducing the levels, inhibiting or reducing the production of pro-fibrotic mediators in a subject at risk of developing, or having kidney disease, the method comprising administering to the subject a composition comprising a pharmaceutically effective amount of vasoactive intestinal peptide (VIP) or one or more functional VIP fragments selected from VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24) or conservative substitutions thereof.
[0028] According to an eleventh aspect, the invention provides a method of reducing collagen formation or enhancing collagen degradation in the kidney of a subject, the method comprising administering to the subject a composition comprising a pharmaceutically effective amount of vasoactive intestinal peptide (VIP) or one or more functional VIP fragments selected from VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24) or conservative substitutions thereof.
[0029] In the context of the present invention certain terms may be used interchangeably or incorporated within a term with a broader meaning. Thus, the term “kidney disorder” or “kidney disease” may be used interchangeably. The term “chronic kidney disease” “kidney disease” may encompass conditions such as kidney fibrosis and kidney failure. The term “associated condition” as used in the context of the present invention is intended to encompass conditions and disorders that arise as a direct consequence of kidney disease as well as conditions that predispose to development or exacerbation of kidney disease. For example, the term “associated condition” in reference to kidney disease may encompass, without limitation, glomerulonephritis, tubulo-interstitial disease, reflux nephropathy, polycystic disease, SLE, vasculitis, scleroderma, Sjogrens Syndrome, gout, hypertension, diabetes and kidney fibrosis.
[0030] The term “prophylactic” as used in the context of the present invention is intended inter alia to encompass treatments used to prevent or slow down the development of fibrosis in the at risk subject. A proportion of subjects that may be given prophylactic treatment may already have signs of kidney disease.
[0031] In the context of the present invention the term “therapeutic” is intended to mean partially or completely curative treatment of an existing condition.
[0032] It will be understood that the present invention also encompasses within its scope certain analogues of the VIP fragments, which are based on conservative substitutions of one or more amino acids of the VIP fragments, with amino acids which do not alter the biological activities of the VIP fragments. Such substitutions would be well known to those skilled in the art and would not require more than simple trial-and-error using well-established techniques. Hence, the term “VIP fragment” as used in the context of the present invention is intended to encompass such analogues.
[0033] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.
BRIEF DESCRIPTION OF THE FIGURES
[0034] FIG. 1 : Renal interstitial fibrosis after infusion of vehicle control or peptide at 5 pmol/kg/min for 4 weeks in the SHR on 2.2% salt diet.
[0035] FIG. 2 : Renal interstitial fibrosis after infusion of vehicle control or peptide at 5 pmol/kg/min for 4 weeks in the SHR on a 2.2% diet. VB 806 f refers to VIP(6-10), VB 806 c refers to VIP(6-20), VB 806 b refers to VIP(6-24).
[0036] FIG. 3 : Renal interstitial fibrosis after infusion of vehicle control or peptide at 5 pmol/kg/min for 4 weeks in SHR on a 2.2% salt diet. VB 804 e refers to VIP(4-12), VB 804 c refers to VIP(4-20), VB 804 b refers to VIP(4-24).
[0037] FIG. 4 : Renal interstitial fibrosis after infusion of vehicle control or peptide at 5 pmol/kg/min for 4 weeks in the SHR on 2.2% salt diet.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] Surprisingly it has now been found that the VIP molecule as a whole, acts to prevent, reduce or reverse kidney fibrosis and thus prevent or slow the progression of chronic kidney disease. Further, in view of the well accepted views held in this field, it has surprisingly been found that VIP fragments lacking amino acids and motifs thought to be important for their function are nevertheless useful therapeutic agents to reverse or delay onset of kidney fibrosis, or prevent onset of fibrosis in subjects at risk of developing kidney disease. Particularly useful VIP fragments can be selected from, but not limited to, VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24). VIP or VIP fragments are also useful in the treatment of kidney failure.
[0039] The use of the pharmaceutical compositions of the invention in the treatment of chronic kidney disease or associated conditions represents a new class of therapeutic agents for these conditions. Existing treatments for chronic kidney disease or associated conditions usually target one, or at the most two, of the known causative mechanisms in chronic kidney disease. Without wishing to be bound by any particular mechanism of action, it is believed that the compositions or pharmaceutical preparations of the present invention may target virtually all the currently known promoters of kidney disease.
[0040] On the basis of the present studies, and not wishing to be bound by theory, it is postulated that VIP or VIP fragments act as major regulators to prevent the development of fibrosis, and that the depletion of VIP may unleash the synthesis of a number of profibrotic mediators, thereby causing kidney injury. The VIP fragments of the present invention seem to be able to act in much the same way as the native VIP but are more suited for therapeutic applications due to smaller size and hence increased stability and ease of manufacture.
[0041] All the sequences relate to VIP and fragments of human origin, but due to the very high level of amino acid conservation, VIP and fragments thereof derived from other mammalian species are also contemplated and encompassed by the present invention.
[0042] The present invention also contemplates pharmaceutical compositions, which include VIP and/or active VIP fragments. Such compositions may include any type of dosage form such as tablets, capsules, powders, liquid formulations, delayed or sustained release, patches, snuffs, nasal sprays and the like. The formulations may additionally include other ingredients such as dyes, preservatives, buffers and anti-oxidants, for example. The physical form and content of the pharmaceutical formulations contemplated are conventional preparations that can be formulated by those skilled in the pharmaceutical formulation field and are based on well established principles and compositions described in, for example, The Science and Practice of Pharmacy, 19 th Edition, 1995 (Mack Publishing Co. Pennsylvania, USA); British Pharmacopoeia 2000, and similar formulation texts and manuals. The compositions of the present invention may also include other active agents useful in the treatment of kidney disease, kidney failure or kidney fibrosis.
[0043] The route and frequency of administration of the compositions of the present invention will depend on the treatment requirements and the nature of the molecule to be administered. Thus the formulations may be suitably prepared for administration by intravenous, intramuscular or subcuticular injection. VIP and/or VIP fragments may also be suitable for mucosal administration such as oral, sublingual, nasal and the like. These parameters are easily established by those skilled in the art.
[0044] The pharmaceutical compositions of the invention have been shown to be effective in preventing or slowing down progression of established kidney fibrosis, as well as in reducing the degree (reversal) of established fibrosis and thus important in therapeutic applications. The compositions of the present invention are also useful for prophylactic or therapeutic treatment of chronic kidney disease. These are important findings with respect to the range and severity of conditions, which can be treated with the compositions of the present invention.
[0045] Further, the compositions of the present invention may be used prophylactically in subjects at risk of developing chronic kidney disease or an associated condition. As an example of subjects in the risk category are those having associated conditions such as hypertension, diabetes, glomerulonephritis, heavy metal poisoning, gout, drugs such as cis-platinum and others which are used in cancer chemotherapy, as well as gold and pencillamine which are used in treatment of rheumatoid arthritis, genetic predisposition, other conditions such as reflux nephritis, SLE and vasculitis and the like.
[0046] By conserving the VIP content of the kidney in a subject with, or at risk of developing, chronic kidney disease or an associated condition, through the use of the compositions of the present invention, significant therapeutic benefits can be achieved. The benefits include reduction of fibrosis, reduction in the level, production or activity of pro-fibrotic mediators, reduction in progression of fibrosis, reduction in collagen formation or enhancing collagen degradation in the kidney.
[0047] The invention will now be described more particularly with reference to non-limiting examples.
EXPERIMENTAL
[0048] All general methodology and techniques have been described in detail in PCT/AU2005/000835, which is incorporated in its entirety herein by reference.
Example 1
Amino Acid Sequence of VIP and VIP Fragments
[0049] All VIP fragments were obtained from or synthesised by Auspep, Australia.
VIP(1-28)—His-Ser-Asp-Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-Lys-Lys-Tyr-Leu-Asn-Ser-Ile-Leu-Asn (SEQ ID NO:1)
VIP (10-28)—Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-Lys-Lys-Tyr-Leu-Asn-Ser-Ile-Leu-Asn (SEQ ID NO:2)
VIP(4-12)—Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg (SEQ ID NO:3)
VIP(4-16)—Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln (SEQ ID NO:4)
VIP(4-20)—Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-Lys (SEQ ID NO:5)
VIP(4-24)—Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-Lys-Lys-Tyr-Leu-Asn (SEQ ID NO:6)
VIP(6-10)—Phe-Thr-Asp-Asn-Tyr (SEQ ID NO:7)
VIP(6-12)—Phe-Thr-Asp-Asn-Tyr-Thr-Arg (SEQ ID NO:8)
VIP (6-16)—Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln (SEQ ID NO:9)
VIP(6-20)—Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-Lys (SEQ ID NO:10)
VIP(6-24)—Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-Lys-Lys-Tyr-Leu-Asn (SEQ ID NO:11)
Example 2
Effect of VIP Fragment Infusion on Kidney Fibrosis in Rat Models of Fibrosis
[0050] For kidney fibrosis experiments, two types of rats were used, spontaneously hypertensive rats (SHR) and normotensive control Wistar-Kyoto rats (WKY) (animals were obtained from Australian Animal Resources, Perth, Western Australia, Australia)
[0000] i) Male spontaneously hypertensive (SHR) rats on 2.2% salt diet
ii) Male Wistar Kyoto (WKY) rats on 4.4% salt diets
[0051] In each model the rats were randomised to VIP(1-28), VIP(10-28), VIP(4-12), VIP(4-16), VIP(4-20), VIP(4-24), VIP(6-10), VIP(6-12), VIP(6-16), VIP(6-20), VIP(6-24). Commencing at 12 weeks of age, the rats were acclimatized to tail cuff blood pressure measurements and handling for 2 weeks. They then underwent operative insertion of an osmotic minipump (Alzet—Manufacturer: Durect Corporation, Cupertino, Calif., USA; Supplier: Bioscientific Gymea, NSW, Australia) which was designed to deliver vehicle alone (Hartman's solution, Baxter Health Care Corporation, USA)—(Controls) or VIP, VIP fragment or analogue at a dose of 4 pmol/kg/min or 5 pmol/kg/min intravenously.
[0052] The infusion was continued for 4 weeks, during which the rats were weighed and their blood pressures measured twice weekly. At the end of the 4 week infusion period, the rats were anaesthetized and their kidneys harvested.
[0053] After fixation in buffered formalin the kidneys were embedded in wax, sectioned and stained with haematoxylin and eosin or with Masson Trichrome (Lomb Scientific, USA).
[0054] For quantitation of interstitial fibrosis, twenty microscopic fields from each kidney were digitized and the amount of fibrosis in each determined as percent surface area using Image-Pro Plus V5.0 software (Cybernetics). The mean value for each rat and subsequently for each infusion group was then determined.
[0055] FIGS. 1 , 2 , 3 and 4 , show reductions in renal interstitial fibrosis which occurred as a result of the infusion of VIP and various VIP fragments for 4 weeks in the SHR on a 2.2% salt diet.
[0056] In the representative data shown in the figures VB 804 e refers to VIP(4-12), VB 804 c refers to VIP(4-20), VB 804 b refers to VIP(4-24), VB 806 f refers to VIP(6-10), VB 806 c refers to VIP(6-20), and VB 806 b refers to VIP(6-24). Results of studies with VIP fragments not specifically shown in the figures were similar to those for the representative fragments shown.
[0057] The importance of the present invention to health care will be immediately apparent to one skilled in the art upon reading this disclosure. Although the capacity to treat chronic kidney disease has improved significantly with the advent of ACE inhibitors, angiotensin receptor blockers and rennin inhibitors, the pharmaceutical preparations of the present invention, which act to prevent the progression of the underlying lesion (fibrosis), or even reverse fibrosis, have the capacity to prevent the escalation of mild to severe disease and hence to substantially reduce the health care burden. The overall size of certain VIP fragments and their activity makes them ideally suitable as targets for drug development.
[0058] It is to be appreciated that other embodiments and variants of the compositions, methods and uses of the invention, in keeping with the teaching and the spirit of the invention described, are contemplated and that these are within the scope of the invention.
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The invention relates to compositions comprising vasoactive intestinal peptide (VIP) or fragments thereof, and the use of such compositions in the treatment of kidney disease, in particular kidney fibrosis, and other associated conditions.
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CONTINUATION-IN-PART APPLICATION
This application is a Continuation-in-Part Application of my co-pending application Ser. No. 14,202 filed Oct. 15, 1993 in my name and my name only as inventor for "BIN." Priority of all subject matter common to said patent application Ser. No. 14,202 and this Application is hereby claimed.
DESCRIPTION OF THE PRIOR ART
1. Field of the Invention
This invention relates to the art of containers, and more particularly to the art of modular, constructable bins for displaying and selling objects along with instructional printed material.
2. Description of the Prior Art
In the past, containers in the form of bins have been provided for holding objects on a desk, counter or like surface. Bins in a variety of shapes have been taught which are capable of holding papers, pencils, printed material and objects such as pills, tablets, capsules, granulated material, paper clip, fasteners and the like. Such containers are called variously desk organizers, holders, trays and other descriptive names. One such organizer is shown and taught in Letters Patent No. 4,991,712 to Wagner. Another such holder is shown in Design Letters Patent No. 261,583 to Labasan. Additional examples of such containers may be seen in Design Letters Patent No. 295,540 to Rabig and Design Letters Patent No. 317,178 to Kheng. These showings are typical in having front and rear walls and parallel side walls, each of varying heights from a floor to make access from the front and sides more easy for the fingers of a person. All of such teachings have certain structural attributes that satisfy certain desires and in many instances requirements for organizing and holding objects of varying shapes and sizes for ready access to users.
Although modular components for building a desired container may be known, it has been desired to provide a container having varying sized compartments for holding pills, capsules and chemical compound tablets while also holding printed paper material, all for ready access to a user, and which can be assembled by attaching together modules in a final configuration that most easily fits on a counter, desk or like surface within other objects which may limit and defined an awkward space available for such a container. It is also desired to provide such a container that, notwithstanding normal configurations of the various modular components, the pills and printed material will be readily accessible. It is also desired to provide such a container which has integrally formed with it, access to instructions, limitations and warnings associated with the pills, etc. being held and made available to a user.
SUMMARY
In brief, in accordance with one aspect of the present invention, a container has a first bin with a compartment for holding pills, capsules and like objects, and with an integral compartment for holding paper on the edges thereof, where the paper is easily contacted by the fingers on the side of the paper and moved through the front of the container. Other objects may be held by additional compartments within the bin. Further, non-removable instructional material may be slidably held and positioned for ready access.
A second bin is constructed for fitting onto said first bin in one of a multiple of configurations by flanges extending from the side of the second bin. The flanges are formed to fit within holes in the first bin, so that the first and the second bins remained a structurally connected unit. The assembly is formed so that multiple choices may be made in adapting the container to selected space.
Other novel features which are believed to be characteristic of the invention, both as to organization and methods of operation, together with further objects and advantages thereof, will be better understood from the following description in which preferred embodiments of the invention are described byway of example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is perspective view of the preferred embodiment of the invention;
FIG. 2 is a perspective view of the preferred embodiment of the invention taken from a different view;
FIG. 3 is a perspective view of a portion of the preferred embodiment of the present invention, showing component parts of the configuration exploded for ease in understanding;
FIG. 4 is a perspective view of further components of the preferred embodiment of the present invention, having such components shown exploded for ease in understanding;
FIG. 5 is a perspective view of modules of the preferred embodiment of the present invention, having a module exploded from the container for ease in understanding;
FIG. 6 is a perspective view of a portion of the preferred embodiment of the present invention having certain alternative parts thereof exploded for clarity in description;
FIG. 7 is cross-sectional view of a portion of the preferred embodiment of the present invention, taken along line 7--7 of FIG. 6;
FIG. 8 is a top view of a modular component of the preferred embodiment of the present invention, showing a printed card extended;
FIG. 9 is a perspective view of an alternative configuration of the preferred embodiment of the present invention; and,
FIG. 10 is a side elevation, partial cross-sectional view of a portion of the alternative configuration taken along line 10--10 of FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention is shown in two different views of perspective in FIGS. 1 and 2 of the accompanying drawings where a bin assembly or container 10 comprises a first or main bin 12, and a second or auxiliary bin 14. The container 10 also comprises a first or upper tray 16 and a second or lower tray 18 attached to the first or main bin 12 so that the first bin 12 sits on top of the two trays 16, 18. The trays 16, 18 each comprise a separate module which can be detached from the first bin 12.
In FIG. 3, the attachment of the trays 16, 18 to the first bin 12 can be better understood, where the first bin 12 is shown exploded from the trays 16, 18. The upper tray 16 has a plurality of dowels 22 extending upwardly from the sides 24 of the tray 16. The sides 24 of the tray 16 are formed together with the frame-type floor or bottom 26, all as may be better seen in FIG. 8, which be described in greater detail below. The lower tray 18 has dowels 28 which are formed and positioned to fit through corresponding holes 30 formed and carefully positioned in the upper tray 16. The dowels 28 of the lower tray 18 extend upwardly from the sides 32 formed on the lower tray 18. The sides 32 of the lower tray 18 are formed with a frame-type bottom 34. When the upper tray 16 is placed on top of the lower tray 18 so that its dowels 28 fit through the corresponding holes 30 of the upper tray 16, the upper tray 16 is attached to the lower tray 18.
A sliding card or sliding insert 36 is formed in a shape that includes a tab 38 and flanges 39. The sliding card 36 is placed within the upper tray 16. A similar card 40 is placed in the lower tray 18. Card 40 has a tab 42 normally protruding from the tray 18 so that it can be seen when the card 40 is slidably recessed within tray 18.
As better seen in FIGS. 4 and 5, the first bin 12 has a first side wall 44 and a second side wall 46 which are generally parallel to each other and are formed from the front of the bin 12 to the rear of the bin 12. For ease of description, the dimension from the front to the rear of the bin 12 will be designated the longitudinal dimension here in this specification. The first bin 12 has a bottom 48 in which are formed carefully positioned holes 50. The holes are positioned to receive the dowels 22 of the upper tray 16 when it is selected to attach the first bin 12 to the upper tray 16, as shown in FIGS. 1 and 2. A bottom aperture 51 is formed in the bottom 48 of the first bin 12.
As may be best seen in FIG. 5, the front of the bin 12 is fitted with a third or front wall 54 which extends across part, but not all of the front of the first bin 12, between the first wall 44 and the second wall 46. The front wall 54 has an opening 56 through which a tab 58 of yet another card is seen protruding. Another compartment 52 is formed in the first bin 12 between wall 60 and the second wall 46. A fourth wall 62 extends substantially all the way across the rear or back of the bin 12. Running between the first wall 44 and the second wall 46 a little offset from the back or fourth wall 62 is a rear partition 64, which defines a rear compartment 66 and a smaller, corner compartment 68. Compartment 68 might be useful for holding pencils and like elongated objects upright. In addition, vertical slots 70 are formed on the rear partition 64, for holding calling cards.
Still as best seen in FIG. 5, the first bin 12 is provided with a removable front divider 72 which can be slid vertically into place between slots or slotted guide 73. In similar manner, a rear divider 74 can be removably positioned vertically by sliding the divider 74 in slotted guide or slots 75. In keeping with the concept of options available with the modular structure of the present invention, either or both of these dividers 72, 74 can be removed at the option of the user, in order to make different sizes for the compartments within the first bin 12.
A dowel 76 is formed to extend upwardly from the partition wall 60. In like manner, dowel 78 extends upwardly from the back or fourth wall 62 of the bin 12. Dowel 80 extends upwardly in like manner from the first, side wall 44. These dowels are positioned to extent into holes formed in the floor of the auxiliary bin 14, as will be explained in greater detail below.
The second bin 14 is provided with a first or side wall 81 and a second or side wall 82 substantially parallel to each other. A third or rear wall 84 extends between the first and the second walls 81, 82 across the back or rear of the bin 14. A fourth or front wall 86 extends across the front of the bin 14 between the first and second walls 81, 82. All walls 81, 82, 84, 86 extend upwardly from the floor 88 of the auxiliary bin 14. The front wall 86 extends upwardly from the floor 88 to a height less than the other, first three walls 81, 82, 84 of the bin 14, allowing easier access to a hand entering from the front.
In the auxiliary bin 14, a rear partition 90 extends upwardly from the floor 88 and extends between the first and second side walls 81, 82 to define a compartment 92. Another partition 94 extends upwardly from the floor 88 longitudinally from the front wall 86 to the rear partition 90 to define compartment 96.
As best seen in FIG. 2, the first bin 12 has fifth wall 97 extending longitudinally from the front to the rear which is generally parallel to the first side wall 44. A sixth wall 98 extends upwardly from the bottom 48 of the bin 12 between the rear of the fifth wall 97 and the rear of the first wall 44, and might be seen as an extension of the back wall 62. A compartment 99 is defined by the first, fifth and sixth walls 44, 97, 98 that can hold papers, cards and like printed material or blank writing pads on their edges. Significantly, the fifth wall 97 has a surface area that is substantially less than the surface area of the first wall 44, to allow fingers of a hand to engage the papers that are retained and stored within the compartment 99. The front of the compartment 99 is open, further, so that the stored papers can be easily slid forward, without obstruction, by the fingers, and removed for use by a user.
The positioning of the second bin 14 in relation to the first bin 12 is capable of several selectable configurations at the option of the user, as may be appreciated by FIG. 5 of the drawings. Holes 100, 102, 104 are formed in the floor 88 of the bin 14 to receive the dowels 76, 78, 80 formed on the first bin 12. The set of holes 100 comprises a first hole 100a, a second hole 100b, a third hole, 100c and a fourth hole 100d. Each of these holes 100 are formed to receive dowel 76, but it may readily be appreciated that the position of bin 14 with bin 12 when the two are attached to each will be different for each of the holes 100a, 100b, 100c, 100d. Similarly, the set of holes 102 comprises a first hole 102a, a second hole 102b, a third hole 102c and a fourth hole 102d . Each of these holes 102a, 102b, 102c, 102d is formed to receive the dowel 78 of the first bin 12. When the dowel 76 is inserted into the hole 100a, the dowel 78 should comfortably fit into hole 102a. Similarly, when the dowel 76 is inserted into hole 100b, the dowel 78 should fit comfortably into hole 102b. Continuing, when the dowel 76 is fitted into hole 100c, the dowel 78 should fit comfortably into hole 102c. Likewise, when the dowel 76 is fitted into hole 100d, the dowel 78 should fit into hole 102d.
The set of holes 104 comprises a first hole 104a and a second hole 104b. There are no holes corresponding to holes 100c and 100d, or to holes 102a and 102b, for such holes would be beyond the side edge of floor 88. When the dowel 76 is fitted into hole 100a and the dowel 78 is fitted into hole 102a, the dowel 80 should fit comfortably into hole 104a. Similarly, when the dowel 76 is fitted into hole 100b , and dowel 78 is fitted into hole 102b, dowel 80 will fit into hole 104b. When the dowel 76 is fitted into either 100c or 100d, and when the dowel 78 is fitted into hole 102c or 102d, the dowel 80 will be beyond the floor 88.
It may be appreciated that by positioning the dowels 76, 78, 80 into selected ones of the corresponding holes 100, 102, 104, the relative position of the bin 14 with respect to the first bin 12 can be changed in one of four selectable configurations. By such positioning, various of the compartments 52, 66, 68 and the main compartment of the bin 12 can be made more, or less accessible.
As best seen in FIG. 2, the upper, auxiliary bin 14 is further formed to have a series of L-shaped flanges extending from its first wall 81 to provide a channel for holding papers, cards and like printed material or blank writing pads on their edges. L-shaped flange 106 extends from the rear of the first wall 81. L-shaped flange 108 extends from the lower edge of first wall 81, almost as an extension of the floor 88. Similarly, L-shaped flange 110 extends from the lower edge of the floor 88, all to form a channel 112 for holding thin material on the edges thereof. It may be seen from the view of FIG. 2, that thin, paper-like material held in the channel 112 can be accessed easily by fingers of the hand, and can be slid forwardly or upwardly to be removed for use, and returned to the channel 112 for storage later.
As may be best seen in FIG. 2, but also in FIG. 5, the L-shaped flanges are extended further to form additional L-shaped flanges 114, 116. In particular, L-shaped flange 114 extends further than flange 110 from the floor 88. In parallel, a second L-shaped flange 116 extends further from the floor 88 from the L-shaped flange 108. Complementally, holes 118, 120 are formed in the first or main bin 12, as better seen in FIG. 1, but also in FIGS. 4 and 6. In particular, the L-shaped flange 114 is formed to fit into the hole 120, while the L-shaped flange 116 is formed to fit into hole 118, reference now being had to FIG. 9.
In FIG. 9, an alternative configuration having the auxiliary bin 14 postioned laterally adjacent to the main bin 12 is shown. The auxiliary bin 14 is attached to the main bin 12 by hooking the L-shaped flanges 114, 116 into corresponding holes 120, 118, as seen in FIG. 10, a partial cross-section elevation view taken along line 10--10 in FIG. 9. As may be appreciated, the notch or removed portion 148 of the second side wall 46 of the main bin 12, and the notch or removed portion 150 of the first side wall 81 of the auxiliary bin 14 align, so that thin material stored in the channel 112 can be grasped by fingers of the hand readily for removing and returning material to the channel 112. In such an alternative assembly 10, the trays 16, 18 normally are removed from the assembly 10, so that the floor 88 of the auxiliary bin 14 and the bottom 48 of the main bin 12 are on the same plane, that is, rest on the same surface. Of course, if the auxiliary bin 14 is made to rest on some sructure elevating it in relation to the main bin 12, the trays 16, 18 might be kept in the assembly 10 when the auxiliary bin 14 and the main bin 12 are attached in the manner of FIG. 9.
In FIG. 6, and in FIG. 7 which is a cross-section of FIG. 6 taken along line 7--7 of FIG. 6, the main bin 12 is shown with a false floor 130 which has as its purpose the incorporation of a slidable insert in a similar manner as the slidable inserts 36, 40 for the trays 16, 18 described in detail above. Knobs or flanges 124, 126 protrude inwardly from the first side wall 44 and the partition side wall 60 at the same height or level within the main compartment of the main bin 12. The main bin floor 130 then rests on these flanges 124, 126. The main bin floor 130 extends from the front wall 54 to the rear partition 64, and from the first side wall 44 to the partition wall 60, to cover and make a floor for the main compartment of the main bin 12. Between the main bin floor 130 and the bottom 48 of the main bin 12 is a space in which rests a slidable insert 132 on which printed instructions and information can be placed. The insert 132 has the tab 58 described above, which is visible substantially at all times. The tab 58 can be used to extend the insert 132 through the hole or opening 56 in the direction of the arrow 134 to make the printed information on the insert 132 visible to the user. The insert can then be recessed through the hole 56 back into the space between the main bin floor 130 and the main bin bottom 48. The insert 132 might be prevented from being entirely removed from the assembly 10, such as by flanges on rear as is representatively shown for the insert 36 (FIG. 8). If such a flange is a part of the insert 132, the insert 132 can be removed entirely from the assembly through the bottom aperture 51 formed in the bottom 48 of the main bin 12. The bottom aperture 51 is formed sufficiently wide so that the insert 132 can be passed through it.
In FIG. 6, further, alternative positions for dividers are shown for the main compartment of the main bin 12. As described above, the dividers 72, 74 can be inserted into the slots or guides 75 and/or 73, and as easily can be removed to make the main compartment configured as desired. In addition, another alternative configuration can be made by inserting the divider 136 in a longitudinal direction in the slots or guides 138 on the rear partition 64 and 140 on the inside of the front wall 54.
In FIG. 8, the operation of the inserts 36, 40 is illustrated when it is desired to have the trays 16, 18 part of the assembly 10. The operation of the insert 36 in the first or upper tray 16 is shown as representative for itself and the insert 40 of the second or lower tray 18, as well. The insert 36 may be extended in the direction of the arrow 142 out through the opening 144 in the front of the tray 16 resulting from the side 24 of the tray 16 being extended slightly around to cover a small portion of the front from both longitudinal sides of the tray 16, as shown. The insert 36 is prevented from being completely removed by the flanges 39 on the rear of the insert 36, which engage the side 24 extended around on the front from both longitudinal sides of the tray 36. A similar opening 146 is provided in the front of the tray 18, as also may be seen in FIGS. 1 and 2.
In operation, the assembly can be configured in several optional ways, in accord with the desires of the user. In one configuration, the trays 16, 18 may be stacked upon each other by inserting the dowels 28 of the lower tray 18 through the holes 30 of the upper tray 16. The sides 32 of the lower tray 18 will sustain the upper tray 16 a spaced distanced from the frame-type bottom 34 of lower tray 18 and result in the opening 146. In a like manner, the main bin 12 is stacked upon the upper tray 16 by inserting the dowels 22 of the upper tray 16 through the holes 50 formed in the bottom 48 of the main bin 12. The sides 24 of the upper tray 16 will sustain the main bin 12 a spaced distance from the frame-type bottom 26 of the upper tray 16, resulting the opening 144. The insert 36 of the upper tray 16, and the inset 40 of the lower tray 18 can be pulled by their corresponding, exposed tabs 38, 42 to extend the inserts 36, 40 as far as desired or until their corresponding flanges 39 prevent further removal by being engaged by the front portion of the sides 24, 32, as described above. The inserts 36, 40 can be recessed within the assembly 10 by pushing on the tabs 38, 42. It is envisaged that, if the bins 12, 14 are to be used for storing medicinal pills and medications, one of the inserts 36 will have dosing information printed thereon, while the other insert 40 may have warning and side effect information printed thereon.
The main bin 12 also has an insert 132 which can be extended and recessed in the directions of arrow 134. Insert 132 might have suggested or recommended applications imprinted thereon. The dividers 72, 74 may be made part of the configuration in order to make more, but smaller compartments within the main bin 12, or both or either of the dividers 72, 74 may be removed to make compartment space in the main bin 12 as desired. Alternatively, both dividers 72, 74 may be removed and the longitudinal divider 136 may be installed within the guides or slots 138, 140 to provide for two longitudinally shaped compartments within the main bin 12.
The auxiliary bin 14 in the assembly 10 may be attached on the top edges of the main bin 12, by inserting the dowels 76, 78, 80 through a selected one of a set of corresponding holes 100, 102, 104, corresponding to each of the dowels 76, 78, 80 formed in the floor 88 of the auxiliary bin 14. If the dowels 76, 78, 80 are inserted into corresponding holes 100a, 102a, 104a the position of the auxiliary bin 14 in relation to the main bin 12 will be slightly forward and to the right, when facing the front of the assembly 10. For clarity in the following description, this position may be considered an "original" position in the relationship of the auxiliary bin 14 to the main bin 12. By selecting to insert the dowels 76, 78, 80 into the corresponding holes 100b, 102b, 104b, the auxiliary bin 14 will be positioned slightly to the rear of the original position described immediately preceding. By selecting to insert the dowels 76, 78 into corresponding holes 100c, 102c, with the dowel 80 not being inserted but hanging free, as it were, the auxiliary bin 14 will be positioned slightly to the left of the original relationship with main bin 12. A fourth selection is to insert the dowels 76, 78 into corresponding holes 100d, 102d and to have the dowel 80 hang free, in which selection the position of the auxiliary bin 14 will be slightly to the left and to the rear of the original position in its relationship with the main bin 12.
Alternatively, the auxiliary bin 14 may be configured by attaching it to the side of the main bin 12. The L-shaped flanges 114, 116 extending from the first side wall 81 of the auxiliary bin 14 are insert in corresponding holes 120, 118 formed in the second side wall and bottom 48 of the main bin 12. This configuration leaves the channel 112 fully capable of storing thin material along the side of the auxiliary bin 14, and readily accessible to fingers of the hand, especially through the notches or removed portions 148, 150 of the adjacent walls 46, 81.
Further, thin material, such as paper, pads, cards and the like may be stored and readily accessed along the side of the main bin 12 in a channel 99. Because the surface area of the wall 97 is substantially less than the surface of the first wall 44, the fingers of the hand can engage by friction the stored material, and slide it forwardly which is formed without obstruction in the front of the main bin 12.
The foregoing description of my invention and of preferred embodiments as to products, compositions and processes is illustrative of specific embodiments only. It is to be understood, however, that additional embodiments may be perceived by those skilled in the art. The embodiments described herein, together with those additional embodiments, are considered to be within the scope of the present invention.
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A modular container provides a first bin having a compartment for holding general shaped objects and a second compartment for holding vertically a pad of paper in the longitudinal dimension relative to the first compartment. The container includes a slidable printing surface extending from and recessing into said first bin while being prevented from complete removal. A second modular bin is removably attachable to the first bin without covering the compartment of the first bin for vertically holding a pad of paper, and is positionable in a plurality of selectable positions.
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CROSS REFERENCE TO RELATED APPLICATIONS
This patent application is a continuation of U.S. patent application Ser. No. 12/473,444 filed on May 28, 2009 which is a continuation-in-part of U.S. patent application Ser. No. 12/262,372 filed on Oct. 31, 2008 and which is now U.S. Pat. No. 7,730,972 issued on Jun. 8, 2010, which is a continuation-in-part of U.S. patent application Ser. No. 12/178,467 filed on Jul. 23, 2008 and which is now U.S. Pat. No. 7,730,975 issued on Jun. 8, 2010, which is a continuation-in-part of U.S. patent application Ser. No. 12/039,608 filed on Feb. 28, 2008 and which is now U.S. Pat. No. 7,762,353 issued on Jul. 27, 2010, which is a continuation-in-part of U.S. patent application Ser. No. 12/037,682 filed on Feb. 26, 2008 and which is now U.S. Pat. No. 7,624,824 issued on Dec. 1, 2009, which is a continuation-in-part of U.S. patent application Ser. No. 12/019,782 filed on Jan. 25, 2008 and which is now U.S. Pat. No. 7,617,886, which is a continuation-in-part of U.S. patent application Ser. No. 11/837,321 filed on Aug. 10, 2007 and which is now U.S. Pat. No. 7,559,379, which is a continuation-in-part of U.S. patent application Ser. No. 11/750,700 filed on May 18, 2007 and which is now U.S. Pat. No. 7,549,489 issued on Jun. 23, 2009, which is a continuation-in-part of U.S. patent application Ser. No. 11/737,034 filed on Apr. 18, 2007 and which is now U.S. Pat. No. 7,503,405 issued on Mar. 17, 2009, which is a continuation-in-part of U.S. patent application Ser. No. 11/686,638 filed on Mar. 15, 2007 and which is now U.S. Pat. No. 7,424,922 issued on Sep. 16, 2008, which is a continuation-in-part of U.S. patent application Ser. No. 11/680,997 filed on Mar. 1, 2007 and which is now U.S. Pat. No. 7,419,016 issued on Sep. 2, 2008, which is a continuation-in-part of U.S. patent application Ser. No. 11/673,872 filed on Feb. 12, 2007 and which is now U.S. Pat. No. 7,484,576 issued on Feb. 3, 2009, which is a continuation-in-part of U.S. patent application Ser. No. 11/611,310 filed on Dec. 15, 2006 and which is now U.S. Pat. No. 7,600,586 issued on Oct. 13, 2009.
U.S. patent application Ser. No. 12/039,608 is also a continuation-in-part of U.S. patent application Ser. No. 11/278,935 filed on Apr. 6, 2006 and which is now U.S. Pat. No. 7,426,968 issued on Sep. 23, 2008, which is a continuation-in-part of U.S. patent application Ser. No. 11/277,394 filed on Mar. 24, 2006 and which is now U.S. Pat. No. 7,398,837 issued on Jul. 15, 2008, which is a continuation-in-part of U.S. patent application Ser. No. 11/277 ,380 filed on Mar. 24, 2006 and which is now U.S. Pat. No. 7,337,858 issued on March 4, 2008, which is a continuation-in-part of U.S. patent application Ser. No. 11/306,976 filed on Jan. 18, 2006 and which is now U.S. Patent No. 7,360,610 issued on Apr. 22, 2008, which is a continuation-in-part of U.S. patent application Ser. No. 11/306,307 filed on Dec. 22, 2005 and which is now U.S. Pat. No. 7,225,886 issued on Jun. 5, 2007, which is a continuation-in-part of U.S. patent application Ser. No. 11/306,022 filed on Dec. 14, 2005 and which is now U.S. Pat. No. 7,198,119 issued on Apr. 3, 2007, which is a continuation-in-part of U.S. patent application Ser. No. 11/164,391 filed on Nov. 21, 2005 and which is now U.S. Pat. No. 7,270,196 issued on Sep. 18, 2007.
U.S. patent application Ser. No. 12/039,608 is also a continuation-in-part of U.S. patent application Ser. No. 11/555,334 filed on Nov. 1, 2006 and which is now U.S. Pat. No. 7,419,018 issued on Sep. 2, 2008. All of these applications are herein incorporated by reference in their entirety.
BACKGROUND
This invention relates to the field of downhole turbins used in drilling. More Specifically, the invention relates to controlling the rotational velocith of downhole turbines.
Previous attempts at controlling downhole turbine speed were performed by diverting a portion of the drilling fluid away from the turbine. It was believed that the diversion of drilling fluid away from the turbine results in less torque on the turbine itself. However, this technique may also require the additional expense of having to over design the turbine to ensure that sufficient torque is delivered when fluid flow is restricted.
U.S. Pat. No. 5,626,200 to Gilbert et al., which is herein incorporated by reference for all that it contains, discloses a logging-while-drilling tool for use in a wellbore in which a well fluid is circulated into the wellbore through a hollow drill string. In addition to measurement electronics, the tool includes an alternator for providing power to the electronics, and a turbine for driving the alternator. The turbine blades are driven by the well fluid introduced into the hollow drill string. The tool also includes a deflector to deflect a portion of the well fluid away from the turbine blades.
U.S. Pat. No. 5,839,508 to Tubel et al., which is herein incorporated by reference for all that it contains, discloses an electrical generating apparatus which connects to the production tubing. In a preferred embodiment, this apparatus includes a housing having a primary flow passageway in communication with the production tubing. The housing also includes a laterally displaced side passageway communicating with the primary flow passageway such that production fluid passes upwardly towards the surface through the primary and side passageways. A flow diverter may be positioned in the housing to divert a variable amount of the production fluid from the production tubing and into the side passageway. In accordance with an important feature of this invention, an electrical generator is located at least partially in or along the side passageway. The electrical generator generates electricity through the interaction of the flowing production fluid.
U.S. Pat. No. 4,211,291 to Kellner, which is herein incorporated by reference for all it contains, discloses a drill fluid powered hydraulic system used for driving a shaft connected to a drill bit. The apparatus includes a hydraulic fluid powered motor actuated and controlled by hydraulic fluid. The hydraulic fluid is supplied to the hydraulic fluid powered motor through an intermediate drive system actuated by drill fluid. The intermediate drive system is provided with two rotary valves and two double sided accumulators. One of the rotary valves routes the hydraulic fluid to and from the accumulators from the drill fluid supply and from the accumulators to the drill bit. The rotary valves are indexed by a gear system and Geneva drive connected to the motor or drill shaft. A heat exchanger is provided to cool the hydraulic fluid. The heat exchanger has one side of the exchange piped between the drill fluid inlet and the drill fluid rotary valve and the other side of the exchange piped between the hydraulic fluid side of the accumulators and the hydraulic fluid rotary valve.
U.S. Pat. No. 4,462,469 to Brown, which is herein incorporated by reference for all that it contains, discloses a motor for driving a rotary drilling bit within a well through which mud is circulated during a drilling operation, with the motor being driven by a secondary fluid which is isolated from the circulating mud but derives energy therefrom to power the motor. A pressure drop in the circulating mud across a choke in the drill string is utilized to cause motion of the secondary fluid through the motor. An instrument which is within the well and develops data to be transmitted to the surface of the earth controls the actuation of the motor between different operation conditions in correspondence with data signals produced by the instrument, and the resulting variations in torque in the drill string and/or the variations in torque in the drill string and/or the variations in circulating fluid pressure are sensed at the surface of the earth to control and produce a readout representative of the down hole data.
U.S. Pat. No. 5,098,258 to Barnetche-Gonzalez, which is herein incorporated by reference for all that it contains, discloses a multistage drag turbine assembly provided for use in a downhole motor, the drag turbine assembly comprising an outer sleeve and a central shaft positioned within the outer sleeve, the central shaft having a hollow center and a divider means extending longitudinally in the hollow center for forming first and second longitudinal channels therein. A stator is mounted on the shaft. The stator has a hub surrounding the shaft and a seal member fixed to the hub wherein the hub and the shaft each have first and second slot openings therein. A rotor comprising a rotor rim and a plurality of turbine blades mounted on the rotor rim is positioned within the outer sleeve for rotation therewith with respect to the stator such that a flow channel is formed in the outer sleeve between the turbine blades and the stator. A flow path is formed in the turbine assembly such that fluid flows though the turbine assembly, flows through the first longitudinal channel in the central shaft, through the first slot openings in the shaft and the stator hub, through the flow channel wherein the fluid contacts the edges of the turbine blades for causing a drag force thereon, and then through the second slot openings in the stator hub and the shaft into the second channel.
BRIEF SUMMARY
In one aspect of the present invention, a downhole drill string assembly has a bore formed there through formed to accept drilling fluid. The assembly also includes a turbine disposed within the bore. The turbine has at least one turbine blade and is in communication with a generator, a gear box, a steering assembly, a hammer element, a pulse telemetry device or any combination thereof.
The downhole drill string assembly further includes at least one flow guide disposed within the bore. The flow guide may be controlled by a feedback loop. The at least one flow guide may include a fin, an adjustable vein, a flexible surface, a pivot point or any combination thereof. The flow guide may be in communication with an actuator. The actuator may be a rack and pinion, a solenoid valve, an aspirator, a hydraulic piston, a flange, a spring, a pump, a motor, a plate, at least one gear, or a combination thereof.
In another aspect of embodiments of the present invention, a method for adjusting the rotation of a turbine is disclosed. This method comprises the steps of providing a downhole drill string assembly having a bore there through to receive drilling fluid, a turbine disposed within the bore and exposed to the drilling fluid, and at least one flow guide disposed within the bore and exposed to the drilling fluid. Then adjusting the flow guide to alter the flow of the drilling fluid, wherein the altered flow of the drilling fluid adjusts the rotation of the turbine.
The adjustment of the rotation of the turbine may comprise slowing down or speeding up of the rotational velocity of the turbine, or increasing or decreasing the rotational torque of the turbine. The adjustments may be controlled by a downhole telemetry system, a processing unit, a control loop, or any combination of the previous. The control loop may control the voltage output from a generator, a rotational velocity of the turbine, or a rotational torque from the turbine. The gain values of the control loop may be adjustable by an uphole computer and fed down to the turbine by a telemetry system or may be autonomously generated by prior programming against a preset target.
The assembly may further include a hammer disposed within the drill string and mechanically coupled to the turbine, wherein an actuation of the hammer is changed by adjusting the rotation of the turbine. The change in the actuation of the hammer may take the form of a change in frequency. This change in actuation may allow the hammer to be used to communicate uphole. The actuating hammer may be able to communicate through acoustic waves, vibrations of the drill string assembly, or changes in pressure created by the hammer impacting the formation or by the hammer impacting a surface within the drill string assembly. The turbine itself may also create a pressure pulse for use in communication or the turbine may actuate a valve to create a pressure pulse for use in communication.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a orthogonal diagram of an embodiment of a drill string assembly suspended in a cross section of a bore hole.
FIG. 2 is a cross-sectional diagram of an embodiment of a drill string assembly.
FIG. 3 is a perspective diagram of an embodiment of a turbine, flow guide, and actuator.
FIG. 4 a is another perspective diagram of an embodiment of a turbine, flow guide, and actuator.
FIG. 4 b is another perspective diagram of an embodiment of a turbine, flow guide, and actuator.
FIG. 5 is another perspective diagram of an embodiment of a turbine, flow guide, and actuator.
FIG. 6 is a perspective diagram of an embodiment of a flow guide and actuator.
FIG. 7 is another perspective diagram of an embodiment of a turbine, flow guide, and actuator.
FIG. 8 is another perspective diagram of an embodiment of a turbine, flow guide, and actuator.
FIG. 9 is a cross-sectional diagram of an embodiment of a turbine, flow guide, and actuator.
FIG. 10 a is another cross-sectional diagram of an embodiment of a turbine, flow guide, and actuator.
FIG. 10 b is another cross-sectional diagram of an embodiment of a turbine, flow guide, and actuator.
FIG. 11 is another cross-sectional diagram of an embodiment of a turbine, flow guide, and actuator.
FIGS. 12 a and 12 b are side view diagrams of an embodiment of a turbine comprising dynamic turbine blades.
DETAILED DESCRIPTION
FIG. 1 is a an orthogonal diagram of an embodiment of a drill string 100 suspended by a derrick 108 in a bore hole 102 . A downhole drill string component having a drilling assembly 103 is located at a bottom of the bore hole 102 and includes a drill bit 104 . As the drill bit 104 rotates downhole, the drill string 100 advances farther into a subterranean formations 105 having the bore hole 102 . The drilling assembly 103 and/or downhole components may have data acquisition devices adapted to gather data that may be used identify a desirable formation 107 and to aid the drill string 100 in accessing the desirable formation 107 . The data may be sent to the surface via a transmission system to a data swivel 106 . The data swivel 106 may send data and/or power to the drill string 100 . U.S. Pat. No. 6,670,880 to Hall et al. which is herein incorporated by reference for all that it contains, discloses a telemetry system that may be compatible with the present invention; however, other forms of telemetry may also be compatible such as systems that include mud pulse systems, electromagnetic waves, radio waves, wired pipe, and/or short hop. The data swivel 106 may be connected to a processing unit 110 and/or additional surface equipment.
Referring now to FIG. 2 , a drilling assembly 103 A compatible with drill string 100 is illustrated. The drilling assembly 103 A may have a jack element 202 A. The jack element 202 A aids in formation penetration and in steering the drill string. A first turbine 207 A and a second turbine 240 A may be located within a bore 208 A formed in the drilling assembly 103 A. The first turbine 207 A or the second turbine 240 A may be adapted for a variety of purposes including, but not limited to power generation, jack element actuation, steering, or hammer actuation.
In the embodiment of FIG. 2 the first turbine 207 A is adapted to rotate the jack element 202 A and the second turbine 240 A is adapted to actuate a hammer element 234 A. A gearbox 211 A disposed in the bore 208 A is adapted to transfer torque from the first turbine 207 A to the jack element 202 A. The rotational speed of the first turbine 207 A is adjustable such that the rotational speed of the jack element 202 A changes. The rotational speed of the second turbine 240 A is adjustable such that the actuation of the hammer element 234 A changes. A downhole processing unit 203 A disposed within the bore 208 A is in communication with a first actuator 204 A and a second actuator 241 A. In the embodiment of FIG. 2 , the actuators 203 A, 241 A includes planetary gear systems 206 A. The first actuator 204 A in further communication with a first at least one flow guide 205 A, and the second actuator 241 A is in turn in communication with a second at least one flow guide 245 A. The downhole processing unit 203 A controls the actuators 204 A, 245 A independently such that the first at least one flow guides 205 A and the second at least one flow guide 245 A are manipulated causing the first turbine 207 A and the second turbine 240 A to change speeds independently.
Adjusting the second at least one flow guide 245 A causes the second turbine 240 A to change rotational speed thereby causing the frequency of the actuation of the hammer element 234 A to change. Through the changing of the frequency of the actuation of the hammer element 234 , uphole communication is possible. The communication signals may take the form of the hammer element 234 A creating acoustic waves from an impact of the hammer element 234 A on the formation, or the impact of the hammer element 234 A on a surface 246 A within the drill string assembly 103 A. The communication signals may also take the form of a vibration of the tool string assembly 103 A or pressure changes of a drilling fluid within the tool string assembly 103 A caused by the hammer element's 234 A actuation. An uphole sensor such as a geophone, a pressure sensor, or an acoustic sensor may be used to receive the communications uphole. Communication along the drill string may also take the form of pressure pulses created by changing the rotational speed of the first turbine 207 A and/or the second turbine 240 A, or by rotating a valve with the first turbine 207 A of the second turbine 240 A.
The processing unit 203 A may also be in communication with a downhole telemetry system, such that an uphole operator can send commands to the first actuator 204 A and the second actuator 241 A. The processing unit 203 A may also have a feedback loop that controls the actuator 204 A. The feedback loop may be controlled by an output of the first turbine 207 A and/or the second turbine 240 A. The controlling output of the first turbine 207 A and/or the second turbine 240 A may include a voltage output from a generator (not shown) that is powered by the first turbine 207 A or the second turbine 240 A respectively, a desired rotational velocity of first turbine 207 A or the second turbine 240 A respectively, or a desired rotational torque of the first turbine 207 A or the second turbine 240 A respectively. The controlling gains of the feedback loop and other aspects of the feedback loop may be adjustable by an uphole computer.
FIG. 3 is a perspective diagram of a portion of an embodiment of a drilling assembly 103 B. In this figure a turbine 207 B, an actuator 204 B and at least one flow guide 205 B are depicted. The actuator 204 B in this embodiment is a plate 301 B. The plate 301 B is disposed axially around the drilling assembly 103 B. The plate 301 B includes pass through slots 302 B adapted to allow fluid to flow through the plate 301 B. The plate 301 B includes attachment points 303 B adapted to attach to at least one flow guide 205 B. The at least one flow guide 205 B has a clamp 305 B.
The clamp 305 B is adapted to attach to the drill assembly 103 B through a connection point 304 B. The flow guide 205 B includes a flexible vane 306 B.
As drilling fluid travels down the drill string and enters into the drilling assembly 103 B the turbine 207 B may begin to rotate. The rotational force generated by the turbine 207 B may be used for a variety of applications including but not limited to generating power or actuating devices downhole. It may be beneficial to control the rotational speed of the turbine 207 B to better meet requirements at a given time.
The plate 301 B may be part of an actuator 204 B such as a gear system or motor that actuates rotational movement. Alternatively, the plate 301 B may hold the flow guide 205 B stationary. A downhole processing unit disposed within the drill string (see FIG. 2 ) or surface processing unit (see FIG. 1 ) may be in communication with the plate 301 B through the actuator 204 B. Rotating the plate 301 B may cause the vanes 306 B to flex and bend such that a downwash angle of the drilling fluid may change below the at least one flow guide 205 B. The flexible vanes 306 B of the flow guide 205 B may also restrict the rotational movement of the plate 301 B.
FIGS. 4 a and 4 b illustrate the portion of an embodiment of a drilling assembly 103 B of FIG. 3 and depict the flexible vanes 306 B in various positions. In this embodiment, drilling fluid 410 B is depicted flowing down the drill string and engaging the turbine 207 B. Adjusting the flexible vanes 306 B by rotating 454 the plate 301 B flexes the flexible vanes 306 B and changes the downwash angle that the drilling fluid 410 B will engage the turbine 207 . Changing the downwash angle causes the turbine 207 B to travel at different speeds based upon the rotation 454 of the plate 301 B. This method is used to slow down or speed up the turbine 207 B or to increase or decrease the torque from the turbine 207 . FIG. 4 a depicts the plate 301 A having no torque applied to it. In this orientation the vanes 306 B are not flexed or bent. The drilling fluid 410 may flow past the vanes 306 B nearly uninterrupted. The drilling fluid 410 B may go on to exert a force on the turbine 207 B by generating lift as it passes the turbine 207 B. In FIG. 4 b the plate 301 B has a torque applied to it rotating the plate such that the vanes 306 B are flexed. The flexed vanes 306 B change the downwash angle of the drilling fluid 410 B. The drilling fluid 410 B engages the turbine 207 B at an angle. The turbine 207 B turns faster in this case due to increased lift than it would in the case depicted in FIG. 4 a.
FIG. 5 depicts a diagram of a portion of an embodiment of a drilling assembly 103 C comprising at least one flow guide 205 C, a turbine 207 C, and a generator 572 C. In this embodiment the rotation of the turbine 207 C actuates the generator 572 C creating electrical power. The at least one flow guide 205 C may be controlled by a feedback loop that is driven by the output voltage of the generator 572 C. In one embodiment, the feedback loop positions the at least one flow guide 205 C in such a way as to prevent the generator 572 C from creating either too little power or too much power. Excess power created by the generator 572 C may turn into heat which can adversely affect downhole instruments and too little power may prevent downhole instruments from operating.
In another embodiment, the positioning of the at least one flow guide 205 C is set by an uphole user. An uphole user may set the position of the at least one flow guide 205 C based upon a flow rate of drilling fluid entering the drilling assembly 103 C, based upon a desired power output, or based upon some other desired parameter.
FIG. 6 depicts a portion of an embodiment of a drilling assembly 103 D having an actuator 204 D and at least one flow guide 205 D. In this this embodiment the at least one flow guide 205 D is a rigid fin 503 D. The fin 503 D attaches to the drill string through a pivot point 504 D. The actuator 204 D in this embodiment is a plate 301 D with slots 501 D disposed around its circumference. The slots 501 D are adapted to receive tabs 502 D disposed on the fins 503 D. The actuator 204 D controls the fins 503 D by rotating the plate 301 D such that the tabs 502 D engaged within the slots 501 cause the fins 503 D to rotate on their pivot point 504 D. The rotated fins 503 D cause drilling fluid to change the angle at which it engages a turbine (not shown).
FIG. 7 is a diagram of an embodiment an embodiment of a drilling assembly 103 E having a turbine 207 E, an actuator 204 E, and at least one flow guide 205 E. The flow guides 205 E in the embodiment of FIG. 7 are fins 503 . In this embodiment the actuator 204 E comprises a rack 601 E and pinion 602 E. The rotation of the rack 601 E causes the fins 503 E to rotate around a pivot point 504 E. The rotated fins 503 E change the angle at which drilling fluid engages the turbine 207 E thereby changing the rotational speed of the turbine 207 E.
FIG. 8 is a depiction of another embodiment of a drilling assembly 103 F having a turbine 207 F, an actuator 204 F and at least one flow guide 205 F. In this embodiment the actuator 204 F is a slider 701 F. The slider 701 F is disposed radially around a central axis of the drilling assembly 103 F. The actuator 204 F includes a motor, a pump, a piston, at least one gear, or a combination thereof, adapted to move the slider 701 F parallel to the central axis of the drilling assembly 103 F. The slider 701 F has at least one flange 702 F. The flow guide 205 F is a fin 503 F connected to the drill string at a pivot point 504 F. The flow guide 205 F further includes a lip 703 F. The flange 702 F of the slider 701 F is adapted to fit on the lip 703 F of the flow guide 205 F. As the slider 701 F moves towards the flow guide 205 F the flange 702 F exerts a force on the lip 703 F causing the fins 503 F to rotate. The rotated fins 503 F change the angle at which drilling fluid engages the turbine 207 F, generating additional lift, and changing the rotational speed of the turbine 207 F.
FIG. 9 is a cross-sectional diagram depicting an embodiment of a drilling assembly 103 G. In this embodiment the actuator 204 G includes a solenoid valve 800 G. The solenoid valve 800 G includes a coil of wire 801 G wrapped circumferentially around a central axis of the drilling assembly 103 G. When the coil of wire 801 G is electrically excited, a slider 701 G is displaced such that a flow guide 205 G is actuated. A preloaded torsion spring 802 G may then return the flow guide 205 G to an original position after the solenoid valve 800 G disengages.
FIGS. 10 a and 10 b depict another embodiment of a drilling assembly 103 H having a turbine 207 H, an actuator 204 H, and a flow guide 205 H. The drill string assembly 103 H has a plurality of turbines 207 H. In this embodiment, the flow guide 205 H a funnel 905 H. As the funnel 905 H is axially translated it alters the flow space across the turbines 207 H. As the funnel 905 H restricts the flow space across the turbines 207 H the drilling fluid velocity increases thus increasing the rotational speed of the turbines 207 H.
The funnel 905 H may be axially translated by means of a Venturi tube 910 H. The Venturi tube 910 H has at least one constricted section 915 H of higher velocity and lower pressure drilling fluid and at least one wider section 920 H of lower velocity and higher pressure drilling fluid. The Venturi tube 910 H also has at least one low pressure aspirator 930 H and at least one high pressure aspirator 940 H. The at least one low pressure aspirator 930 H that may be opened by at least one low pressure valve 935 H and the at least one high pressure aspirator 940 H may be opened by at least one high pressure valve (not shown). When the high pressure aspirator 940 H is opened and the low pressure aspirator 930 H is closed, the drilling fluid flows from the bore 208 H to a chamber 950 H. A piston element 955 H attached to the funnel 905 H and slidably housed within the chamber 950 H forms a pressure cavity. As drilling fluid flows into the chamber 950 H the pressure cavity expands axially translating the funnel 905 H. (See FIG. 10 a ) If the low pressure aspirator 930 H is opened and the high pressure aspirator 940 H is closed, the drilling fluid flows from the pressure chamber 950 H to the bore 208 H. As drilling fluid flows out of the chamber 950 H the pressure cavity contracts reversing the axial translation of the funnel 905 H. (See FIG. 10 b )
FIG. 11 illustrates an embodiment of a flow guide 205 J in the form of a funnel 905 J. In this embodiment the funnel 905 J may be axially translated by means of at least one motor 1001 J. The motor 1001 J is in communication with a rack 1005 J and pinion 1010 J. The rack 1005 J is connected to the funnel 905 J and the pinion 1010 J is a worm gear. As the pinion 1010 J is rotated by the motor 1001 J the rack 1005 J and funnel 905 J are axially translated.
FIGS. 12 a and 12 b illustrate an embodiment of a turbine 207 K having at least one turbine blade 1107 . The turbine blade 1107 is aligned along an initial vector 1110 . The turbine blade 1107 may rotate a given angle 1115 to a subsequent vector 1120 . The given angle 1115 may remain the same for several rotations of the turbine blade 1107 or the given angle 1115 may vary for different rotations. Rotation of the turbine blade 1107 from the initial vector 1110 to the subsequent vector 1120 may alter the rotational speed of the turbine 207 K.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.
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In one aspect of the present invention, a downhole drill string assembly comprises a bore there through to receive drilling fluid. A turbine may be disposed within the bore and exposed to the drilling fluid. At least one flow guide may be disposed within the bore and exposed to the drilling fluid wherein the flow guide acts to redirect the flow of the drilling fluid across the turbine. The flow guide may be adjusted by an actuator. Adjustments to the flow guide may be controlled by a downhole telemetry system, a processing unit, a control loop, or any combination thereof. In various embodiments the turbine may comprise rotatable turbine blades.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Application No. 61/767,503, filed Feb. 21, 2013, the complete disclosure of which is incorporated by reference herein in its entirety.
BACKGROUND
[0002] Many types of implantable medical devices require a source of electrical energy. For example, pacemakers, defibrillators, drug infusion pumps, cochlear implants, and brain activity monitoring/stimulation systems all require a power source. Many of these implantable medical devices provide therapy and/or diagnostic functions, and have significant electrical power requirements.
[0003] Electrical current used to supply the electrical power required by an implanted medical device can be conveyed through an electrical lead that is connected to the device and extends outside the patient's body for connection to an external power source. However, a transcutaneous lead that passes through the skin increases the risk of infection when left in place for an extended period. Implanted medical devices may also be powered by a non-rechargeable battery. However, replacement of such a battery subjects the patient to further surgery, and thus, may not be desirable, particularly if replacement is frequently necessary.
[0004] As an alternative to a non-rechargeable battery, an implanted rechargeable battery can be recharged by transcutaneously coupling power from an external source to an implanted receiver that is connected to the rechargeable battery. One of the more efficient recharging techniques employs an external transmission coil and an internal receiver coil, which are inductively coupled so that power can be conveyed from the transmission coil to the receiver coil. In this transcutaneous energy transmission (TET) approach, the external primary transmission coil is energized with alternating current (AC), producing a time varying magnetic field that passes through the patient's skin and induces a corresponding AC in the internal secondary receiving coil. The voltage induced in the receiving coil may then be rectified to provide direct current (DC) that is used to power the implanted medical device and/or charge a battery or other charge storage device (e.g., an ultra capacitor), which continues to energize the implanted medical device after the inductive supply of electrical power is terminated. This transcutaneous energy transmission work was originally pioneered by J. C. Schuder in 1961 (J. C. Schuder, H. E. Stephenson, and J. F. Townsend, “High level electromagnetic energy transfer through a closed chest wall,” IRE International Convention Record 9, part 9, pp. 119-126, 1961).
[0005] One challenge in designing TET systems is that eddy currents are induced in the metallic components (such as the housing or printed circuit boards) of the implanted medical device. Such eddy currents can produce a generally undesirable temperature increase or heating of the implantable device. The amount of heat generated is generally a function of the amplitude and frequency of the magnetic flux used in the TET system.
[0006] Additional thermal challenges presented in TET systems are caused by the heat produced within the external transmission coil and its associated external enclosure. One problem is that temperature increases in the external transmission coil decreases the efficiency of the TET system. For example, heating of the primary coil increases the resistance of the windings, which serves to reduce the amount of power transferred to the implantable unit, thereby increasing the time required for recharging, resulting in further heating of the external transmission coil enclosure and the heating of the implanted medical device. A second problem is that as the external transmission coil heats up, such heat can be transferred to the external housing surrounding the coil. That housing is located proximal to the patient's skin nearest the implanted medical device, and such a temperature increase can increase the skin temperature.
[0007] Implanted medical devices are generally surrounded by tissue, which to a certain extent will conduct heat away from the device. However, implanted device temperatures exceeding safe thresholds may injure or permanently damage surrounding tissue. The ability of human tissue to withstand hyperthermic conditions is governed by a complex relationship of factors including tissue type, temperature, and exposure time. It would be desirable to provide a method and apparatus that reduces the risk of damaging adjacent tissue during the recharging of implanted medical devices when using TET. Furthermore, the amount of transmitted power is primarily limited by the heating of (i) the tissue surrounding the implanted device; (ii) the skin surface adjacent to the external charging device; and (iii) the temperature of the external charging device. Such aforementioned heating limits the amount of power that may be transferred by the TET system, which increases the time required for recharging. Since the patient is typically inconvenienced during the recharging period, it would be desirable to maximize the power rate of transfer while minimizing associated heating. Prospective techniques for accomplishing that may employ one or more of the following strategies: (1) minimizing the heat caused by induced eddy currents; (2) transferring heat away from the tissue surrounding the implantable medical device; (3) reducing the operating temperature of the external components of the TET system; and, (4) isolating any temperature elevation of the external components of the TET system from the tissue proximate the implanted medical device.
SUMMARY
[0008] The concepts disclosed herein encompass the use of a phase change material (PCM) adjacent to the external charging component of a TET system. The PCM may function as a heat sink for one or more of: (a) the skin and tissue surrounding the implanted medical device; and (b) the external transmission coil. In the case where the PCM functions as a heat sink for the skin and tissue surrounding the implanted medical device, the PCM minimizes the amount of thermal energy that is transferred from the external component of the TET system to the adjacent tissue, and absorbs heat from the skin and tissue surrounding the implanted medical device, which reduces the thermal load on the tissue. In the case where the PCM functions as a heat sink for the external transmission coil, the PCM serves to minimize the amount of thermal energy which is transferred from the external component of the TET system to the adjacent tissue, as well as to absorb heat from the primary transmission winding. A PCM is a substance exhibiting a relatively large latent heat of fusion which, during a phase transition, is capable of respectively absorbing or releasing a relatively large amount of thermal energy. Heat is absorbed when the material changes from a more-ordered state to a less-ordered state (e.g., from a solid to a liquid or gas, or from a liquid to a gas), and is released during the opposite phase change (e.g., from a gas to a solid or liquid, or from a liquid to a solid).
[0009] When PCMs reach the temperature at which they change phase (e.g., their phase transition temperature), they may absorb relatively large amounts of heat while maintaining an almost constant temperature. The PCM may continue to absorb heat without a significant rise in temperature until all the PCM material is transformed to another phase. In an exemplary embodiment in which a solid changes phase into a liquid, when the ambient temperature around a liquid material falls, the PCM solidifies, releasing its stored latent heat. A large number of PCMs are available for various temperature ranges from about −5° C. up to about 190° C. Within the human comfort range of about 20° C. to about 40° C., some PCMs are very effective. They can absorb from about 5 to about 14 times more heat per unit volume than conventional heat sink materials that do not experience a phase change.
[0010] PCMs can be grouped into three categories, including organic PCMs, inorganic PCMs, and composite PCMs (e.g., eutectic mixtures). Organic PCMs include fatty acids (CH 3 (CH 2 ) 2n COOH) and paraffin waxes with hydrocarbon chains of between 14 and 22 carbon atoms (C n H 2n+2 ), which have melting points (i.e., solid to liquid phase transition points) between about 6° C. and about 41° C. Specific waxes that can be used for this purpose include (but are not limited to): eicosane (with a chain of twenty carbon atoms having a melting point of 36.6° C.) octadecane (with a chain of eighteen carbon atoms having a melting point of 28.1° C.), and hexadecane (with a chain of sixteen carbon atoms having a melting point of 18° C.). The first two of those three exemplary waxes experience only about a 7% density change during the liquid-to-solid transition, which represents one of the lower density changes of a PCM and is advantageous with respect to packaging considerations. An additional advantage of using such waxes as a PCM is that there is minimal chance of phase separation, since tests have been conducted to phase-cycle such materials as many as 30,000 times without any shift in their thermal capacity. Inorganic PCM materials include: hydrated salts (such as zinc nitrate, which melts at 36.2° C.) and anhydrous salts (such as meta phosphoric acid HPO 4 and Glaubers salt (Na 2 SO 4 10H 2 O), which changes phase at 32.2° C.).
[0011] PCMs can also be encapsulated within capsules such as 3 -mm spherical beads. Such macro capsule PCMs are available through Microtek Laboratories, Inc. (Dayton, Ohio), and are used in cooling vests or garments. The macro capsule PCM particles are used to regulate the body temperature of individuals who work in hot environments, e.g. soldiers in a desert setting. The macro capsule PCMs absorb excess heat and permit the user to function for a longer time at a more comfortable temperature.
[0012] Thus, one aspect of the concepts disclosed herein is a TET system, including an external charging accessory (ECA) and a PCM, where the system is adapted for energizing an implanted medical device. The ECA includes an induction coil for transferring energy to the implanted medical device. The PCM is generally adjacent to the ECA, and may be in contact with the patient's skin or clothing. In some embodiments, the PCM is configured to remove heat from tissue proximate the implanted medical device, such heat having been generated by eddy currents induced in the implanted medical device during recharging. The PCM can also be thermally coupled to the ECA, to function as a heat sink for thermal energy produced by the ECA. Alternatively, the PCM material can be thermally isolated from the ECA (for example, by using a non-thermally conductive PCM membrane, an air gap, or a non-thermally conductive ECA housing), so as to reserve the PCM material to act as a heat sink only for the patient's tissue, as opposed to acting as a heat sink for both the patient's tissue as well as the ECA. In at least one exemplary embodiment, the PCM is encapsulated in a housing separate from that of the ECA. In a related exemplary embodiment, the PCM is disposed between the ECA and the patient.
[0013] The PCM material may be contained within a housing and/or membrane, in order to contain liquid or gas formed when the PCM material undergoes a phase change from a solid to a liquid or gas, or from a liquid to a gas. However, in order to eliminate the need for manufacturing a leak-resistant housing or membrane, in at least one embodiment disclosed herein such PCM macro capsules are encapsulated within a thermally conductive epoxy, which would eliminate the need for a PCM housing material.
[0014] Additionally, the use of PCM material is not limited to a single phase transition point (e.g., a single melting point or a single sublimation point). In some embodiments, a mixture of two or more PCM materials having different transition points may be used in order to optimize the heat accumulation properties.
[0015] This Summary has been provided to introduce a few concepts in a simplified form that are further described in detail below in the Description and illustrated in the accompanying Drawings. The Summary is not intended to limit the scope of the invention, which is defined solely by the claims attached hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1A is a cross-sectional view of an exemplary embodiment of a self-cooling TET system including an ECA and a cylindrical PCM heat accumulation structure thermally coupled to the patient's skin and surrounding a portion of an exterior of the ECA, where the ECA is being used to transfer energy to an implanted medical device.
[0017] FIG. 1B is a cross-sectional view of another exemplary embodiment of a self-cooling TET system in which the PCM heat accumulation structure is disposed between the ECA and the patient.
[0018] FIG. 1C is a cross-sectional view of still another exemplary embodiment of a self-cooling TET transfer system illustrating a PCM heat accumulation structure that combines features of the embodiments of FIGS. 1A and 1B , in that the PCM heat accumulation structure both generally surrounds the ECA and is disposed between the ECA and the patient.
[0019] FIG. 1D is a cross-sectional view of another exemplary embodiment of a self-cooling TET, illustrating a PCM heat accumulation structure disposed within a cylindrical volume defined by the toroidal shape of the external ECA housing containing the primary coil.
[0020] FIG. 1E is a cross-sectional view of another exemplary embodiment of a self-cooling TET, illustrating a PCM heat accumulation structure disposed within the cylindrical volume defined by the toroidal shape of the external ECA housing containing the primary coil.
[0021] FIG. 1F is a cross-sectional view of another exemplary embodiment of a self-cooling TET, illustrating a PCM heat accumulation structure disposed within the cylindrical volume defined by the toroidal shape of the external ECA housing containing the primary coil of the ECA and also disposed between the ECA and the patient.
[0022] FIG. 1G is a cross-sectional view of another exemplary embodiment of a self-cooling TET, illustrating a PCM heat accumulation structure that is both disposed within the cylindrical volume defined by the toroidal shape of the external ECA housing containing the primary coil of the ECA and surrounding an outer portion of the ECA housing, and is further disposed between the ECA and the patient.
[0023] FIG. 1H shows an exemplary toroidal shaped external ECA housing including a hollow central volume.
[0024] FIG. 2 is a cross-sectional view of the embodiment of FIG. 1F , with the addition of a fan that is configured to remove thermal energy accumulated by the PCM.
[0025] FIG. 3 illustrates a patient and shows a strap or harness that may be attached to the patient to secure the ECA and the PCM heat accumulation structure in a desired position.
[0026] FIG. 4 illustrates an embodiment in which the secondary coil implanted within the patient is spaced apart from the implanted medical device.
[0027] FIG. 5A is a top-view of an embodiment in which the primary coil is spaced apart from the ECA.
[0028] FIG. 5B is a side-view of the embodiment of FIG. 5A , also showing the PCM heat accumulation structure, which has been removed from the inside hollow central volume of the ECA.
[0029] FIG. 6A illustrates a patient and shows an alternative strap or harness that may be attached to the patient to secure the ECA and the PCM heat accumulation structure in a desired position relative to a cooling system.
[0030] FIG. 6B is a cross-sectional view similar to the embodiment of FIG. 2 , with the addition of cooling tubes of a cooling system similar to the embodiment of FIG. 6A .
[0031] FIG. 7A illustrates a patient and shows yet another alternative strap or harness that may be attached to the patient to secure the ECA and the PCM heat accumulation structure in a desired position relative to an alternative cooling system.
[0032] FIG. 7B is a cross-sectional view similar to the embodiment of FIG. 1A , with the addition of cooling tubes of a cooling system similar to the embodiment of FIG. 7A .
[0033] FIG. 8 is a cross-sectional view similar to the embodiment of FIG. 2 , with the addition of vents of an expanded housing.
DESCRIPTION
[0034] Exemplary embodiments are illustrated in referenced Figures of the drawings. It is intended that the embodiments and Figures disclosed herein are to be considered illustrative rather than restrictive. No limitation on the scope of the technology and of the claims that follow is to be imputed to the examples shown in the drawings and discussed herein.
[0035] In the drawings described below, reference numerals are generally repeated where identical elements appear in more than one Figure.
[0036] FIG. 1A is a cross-sectional view of an exemplary embodiment of a self-cooling TET system including an ECA 10 , a PCM heat accumulation structure 40 a that is thermally coupled to the patient's skin and generally surrounding a portion of an exterior of the ECA that is being used to transfer energy to an implanted medical device 80 . It should be recognized that in some embodiments, an implantable medical device will be considered as part of the present system (e.g., in embodiments where the ECA, PCM heat accumulation structure, and implantable medical device are sold as a package), while in some other embodiments, the implantable medical device will not be considered as part of the system (e.g., in embodiments where the ECA and PCM heat accumulation structure are sold separately from the implantable medical device).
[0037] The ECA includes an outer housing, a bobbin 20 (e.g., a spindle or cylindrical core), and a primary induction coil 30 , contained within a common housing (although as will be discussed in greater detail below, if desired, the components can be disposed of in different housings). The ECA transfers electromagnetic energy to implanted medical device 80 (shown disposed within a subcutaneous pocket 60 that is formed between a dermal layer 50 underlying muscular tissue 70 ).
[0038] During the charging process, ECA 10 is placed on the patient's body (either directly contacting the patient's dermal layer or a relatively thin layer of clothing). The charger may simply rest upon the patient's body, with the patient in a generally supine or sitting position, or the housing may be held in position relative to the patient via a strap or harness 15 , as illustrated in FIG. 3 . The strap enables a patient to be ambulatory, assuming that the ECA is battery operated, or in the case where the ECA is powered via an electrical outlet, the ambulatory state will be subject to limitations of any power supply line providing electrical energy to the ECA during the energy transfer process. If desired, a thermally conductive adhesive pad (or non-thermally conductive, for the case where the PCM is only being used as a dynamic heat sink for the ECA and not the skin—thereby thermally isolating the skin from the ECA) may be used to temporarily hold ECA 10 in place against dermal layer 50 , in addition to, or in lieu of harness 15 .
[0039] Primary induction coil 30 within ECA 10 produces an alternating magnetic field, which couples to the secondary coil (not separately shown) within implanted medical device 80 , inducing an alternating current (AC) to flow within the secondary coil. The induced AC is then rectified producing a direct current (DC) that is used to charge the rechargeable energy source (e.g., a rechargeable battery or capacitor, also not shown) within implanted medical device 80 . The magnetic flux also induces eddy currents on and within metallic portions of implanted medical device 80 , causing undesired heating. The heat generated within implanted medical device 80 is conducted to tissue 70 , causing a temperature rise to occur. In order to prevent tissue 70 from being heated to an undesirable temperature (e.g., above a potentially damaging threshold of about 42° C.), a PCM heat accumulation structure 40 a is disposed proximate dermal layer 50 , to function as a heat sink for thermal energy generated in implanted medical device 80 . In the exemplary embodiment illustrated in FIG. 1A , PCM heat accumulation structure 40 a also functions as a heat sink for thermal energy generated by ECA 10 . Thus, PCM heat accumulation structure 40 a is configured to surround at least a portion of an external housing of ECA 10 . FIG. 5B illustrates a solid model of the ECA and the PCM heat accumulation structure, where the PCM heat accumulation structure has been removed from the central volume defined by the primary induction coil in the external charging unit.
[0040] The PCM heat accumulation structure 40 a has a housing/enclosure 48 a that is separate and distinct from ECA 10 , such that once PCM heat accumulation structure 40 a has absorbed a maximum amount of thermal energy so as to completely change its state, it can be removed and replaced with a unit whose PCM is still in a solid state (or still in a liquid state). This replacement may be accomplished easily without excessive disruption to the charging process. While it would be possible to integrate the PCM heat accumulation structure and the ECA in a common housing, the use of separate enclosures represents a desirable (but not limiting) embodiment. PCM heat accumulation structure 40 a includes a volume of PCM 45 contained within enclosure 48 a, which can be implemented using a variety of materials. For example, enclosure 48 a can be either a rigid material or a flexible material which may conform to the patient's body. Different portions of enclosure 48 a can be formed from different materials. A portion 43 of enclosure 48 a proximate dermal layer 50 can be formed of a thermally conductive material to allow thermal energy to be conducted away from tissue 70 and towards PCM 45 . Such thermally conductive material may include but are not limited to thermally conductive elastomers marketed under the trade name Cool Poly™, and thermally conductive co-polyester elastomers. The PCM acts as a heat sink, adsorbing thermal energy generated in the implanted medical device, effectively maintaining the adjacent tissue temperature below the 42° C. threshold, so long as the PCM selected has an appropriate phase transition point.
[0041] The optimal phase-transition temperature of PCM 45 is above the normal ambient temperature at which PCM heat accumulation structure 40 a is stored when the TET system is not being used for supplying power or recharging a storage component in an implanted medical device, to ensure that PCM 45 is in the solid phase (or liquid phase) before use, so that the PCM is able to absorb thermal energy during the TET charging periods. (It will be understood that the PCM absorbs thermal energy as it undergoes a phase transition, e.g., melts or changes from a solid to a liquid, vaporizes from a liquid to a gas, or sublimates from a solid to a gas.) In some applications, it is desirable that the phase transition temperature of the PCM be less than the 42° C. threshold. For example, the phase transition temperature of the PCM can range from about 30° C. to about 42° C.
[0042] Given the volume and type of PCM selected, PCM heat accumulation structure 40 a will exhibit an upper thermal capacity limit. Once the thermal capacity is met (meaning that the entire mass of PCM 45 will have undergone a phase change from, e.g., solid to liquid), PCM heat accumulation structure 40 a will no longer function as an effective heat sink, but will instead continue increasing in temperature. Replacing a spent PCM heat accumulation structure 40 a with a fresh PCM heat accumulation structure 40 a will enable continued operation of the TET system by enabling the fresh PCM to absorb more heat before the temperature exceeds the desired limit. In at least one exemplary embodiment, each PCM heat accumulation structure 40 a will include an optional feature 41 enabling a user to determine if the phase change (e.g., from solid to liquid) has occurred and has gone to completion. A simple feature that provides this functionality can be a window enabling the user to visually observe the phase change. More sophisticated features can provide a sensor and an alarm, such as a visible light or audible tone alerting the user that the PCM heat accumulation structure 40 a is spent. It should be recognized that such a feature can be incorporated into any of the exemplary embodiments disclosed herein. Further, the specific location of feature 41 in the PCM heat accumulation structure shown in FIG. 1A is intended to be exemplary, rather than limiting.
[0043] Given the large variance in ambient temperatures throughout the world, it is also possible to have multiple PCM devices optimized for different ambient temperatures. Furthermore, for medical device implants which are located deeper within the patient's body, longer charging times will be required, therefore PCM devices having larger thermal capacities may also be offered. For example, in areas of higher ambient temperatures (such as the Southeastern United States), in order for a PCM to remain in a pre-transition form (e.g., a solid form) at an elevated ambient temperature, one might select a melting point closer to 42° C. than 30° C. On the other hand, if one expected the charging time to be long (due to a deep implant or a low battery level) one could select a PCM that had a low phase transition point (e.g. 15° C.), which would likely require the PCM to be stored in a refrigerator (or some other environment which is cooler than the ambient operating temperature) prior to use.
[0044] In at least some embodiments, a portion 46 a of enclosure 48 a proximate ECA 10 is formed of a thermally conductive material to allow thermal energy to be conducted away from ECA 10 and towards PCM 45 . This configuration enables the ECA to run cooler and operate efficiently (electrical components in the ECA also can generate undesired thermal energy; for example, the primary winding generates heat as AC current runs through the winding, and the overall efficiency of the TET system decreases). However, the thermal capacity of the PCM will then be reached more quickly, since the PCM will be absorbing thermal energy from both the implanted medical device and the ECA. In at least one embodiment, to reserve the thermal absorbing capacity of PCM 45 for the purposes of absorbing thermal energy from tissue 70 (and not from ECA 10 ), portion 46 a can be formed from a thermally insulating material. Alternatively, an air gap (not specifically shown, although it should be recognized that reference numeral 46 a can be understood to indicate such an air gap, as opposed to a portion of enclosure 48 a ) can be disposed between ECA 10 and PCM heat accumulation structure 40 a.
[0045] In an alternative embodiment, the thermal capacity of the PCM may be exclusively reserved for absorbing thermal energy from the ECA. In such an embodiment, portion 43 of enclosure 48 a proximate dermal layer 50 can be formed of a thermally non-conductive material, to prevent thermal energy from being conducted away from tissue 70 and towards PCM 45 , and/or an air gap can be disposed between the PCM and the skin.
[0046] FIG. 1B is a cross-sectional view of another exemplary embodiment of a self-cooling TET system in which a PCM heat accumulation structure 40 b is disposed between ECA 10 and dermal layer 50 of the patient. In this embodiment, portion 43 of enclosure 48 b (the portion proximate dermal layer 50 ) may be formed out of a thermally conductive material. If the thermal capacity of PCM 45 is to be dedicated to absorbing thermal energy from implanted medical device 80 , then either portion 46 b of enclosure 48 b can be formed of a thermally insulating material, or an air gap can be incorporated into the system proximate portion 46 b, generally as described above. Alternatively, the housing for ECA 10 can be made of thermally insulating material. It should be recognized that combinations and permutations of these techniques and the use of other types of thermal insulation can be employed to prevent the thermal capacity of the PCM from being used to absorb heat from ECA 10 . Of course, portion 46 b of enclosure 48 b can instead be formed of a thermally conductive material, such that PCM heat accumulation structure 40 b can be used to absorb heat both from ECA 10 and implanted medical device 80 .
[0047] Additionally, if the thermal capacity of PCM 45 is to be exclusively dedicated to absorbing thermal energy from ECA 10 , then either portion 43 of enclosure 48 b (the portion proximate dermal layer 50 ) can be formed of a thermally insulating material, or an air gap can be incorporated between PCM enclosure 48 b and dermal layer 50 .
[0048] FIG. 1C is a cross-sectional view of still another exemplary embodiment of a self-cooling TET transfer system illustrating a PCM heat accumulation structure 40 c that combines features of the exemplary embodiments of FIGS. 1A and 1B , in that PCM heat accumulation structure 40 c both generally surrounds ECA 10 and is disposed between the ECA and dermal layer 50 of the patient. As discussed above, if the thermal capacity of PCM 45 is to be dedicated to absorbing thermal energy from implanted medical device 80 and associated surrounding tissue, then either portion 46 c of PCM enclosure 48 c can be formed of a thermally insulating material, or an air gap can be incorporated into the system proximate portion 46 c, or the housing for ECA 10 can be made of thermally insulating material. Again, it should be recognized that combinations and permutations of these techniques can be used to prevent the thermal capacity of the PCM from being used to absorb heat from ECA 10 . Similarly, portion 46 c of enclosure 48 c can instead be formed of a thermally conductive material, such that PCM heat accumulation structure 40 c can be used to absorb heat both from ECA 10 and implanted medical device 80 and associated surrounding tissue.
[0049] Additionally, if the thermal capacity of PCM 45 is to be exclusively dedicated to absorbing thermal energy from ECA 10 , then either portion 43 of enclosure 40 c (the portion proximate dermal layer 50 ) can be formed of a thermally insulating material, or an air gap can be incorporated between PCM enclosure 48 c and dermal layer 50 .
[0050] FIG. 1D is a cross-sectional view of another exemplary embodiment of a self-cooling TET system illustrating a PCM heat accumulation structure 40 d disposed within a volume defined by primary coil 30 of ECA 10 (note in such an embodiment, the housing for ECA 10 is toroidal in shape, and the cylindrical cavity defined by the toroidal housing provides the cavity in which PCM heat accumulation structure 40 d is disposed). If the finite thermal capacity of PCM heat accumulation structure 40 d is to be reserved for absorbing thermal energy from implanted medical device 80 and surrounding tissue (as opposed to also absorbing thermal energy from ECA 10 ), a thermally non-conductive material can be used for a portion 46 d of enclosure 48 d, or for the housing of ECA 10 , or an air gap can be disposed between the ECA and the PCM heat accumulation structure, generally as discussed above. If PCM heat accumulation structure 40 d is intended to both absorb thermal energy from ECA 10 and the implanted medical device and surrounding tissue, then portion 46 d can instead be implemented using a thermally conductive material.
[0051] Additionally, if the thermal capacity of PCM 45 is to be exclusively dedicated to absorbing thermal energy from ECA 10 , then either portion 43 of enclosure 40 d (the portion proximate dermal layer 50 ) can be formed of a thermally insulating material, or an air gap can be incorporated between PCM enclosure 48 d and dermal layer 50 .
[0052] FIG. 1E is a cross-sectional view of another exemplary embodiment of a self-cooling TET system, illustrating a PCM heat accumulation structure 40 e , coupled to the exterior of ECA 10 specifically within a toroidal volume defined by primary coil 30 of ECA 10 and also generally surrounding a portion of an exterior of ECA 10 . This embodiment combines the elements of the exemplary embodiments illustrated in FIGS. 1A and 1D . If PCM heat accumulation structure 40 e is to be reserved for absorbing thermal energy from implanted medical device 80 and surrounding tissue (as opposed to also absorbing thermal energy from ECA 10 ), the techniques discussed above can be used to thermally isolate the ECA from the PCM. If PCM heat accumulation structure 40 e is instead intended to absorb thermal energy from ECA 10 , then portions 46 e of enclosure 48 e can be fabricated using a thermally conductive material.
[0053] Additionally, if the thermal capacity of PCM 45 is to be exclusively dedicated to absorbing thermal energy from ECA 10 , then either portion 43 of enclosure 40 e (the portion proximate dermal layer 50 ) can be formed of a thermally insulating material, or an air gap can be incorporated between PCM enclosure 48 e and dermal layer 50 .
[0054] FIG. 1F is a cross-sectional view of another exemplary embodiment of a self-cooling TET system, illustrating a PCM heat accumulation structure 40 f disposed on an exterior of ECA 10 specifically within a volume defined by primary coil 30 of ECA 10 and also disposed between the ECA and dermal layer 50 of the patient. This embodiment combines the elements of the exemplary embodiments illustrated in FIGS. 1B and 1D . If PCM heat accumulation structure 40 f is to be reserved for absorbing thermal energy from implanted medical device 80 (as opposed to also absorbing thermal energy from ECA 10 ), the techniques discussed above can be used to thermally isolate the ECA from the PCM. If PCM heat accumulation structure 40 f is intended to instead absorb thermal energy from ECA 10 , then portion 46 f of enclosure 48 f can be fabricated using a thermally conductive material.
[0055] Additionally, if the thermal capacity of PCM 45 is to be exclusively dedicated to absorbing thermal energy from ECA 10 , then either portion 43 of enclosure 40 f (the portion proximate dermal layer 50 ) can be formed of a thermally insulating material, or an air gap can be incorporated between PCM enclosure 48 f and dermal layer 50 .
[0056] FIG. 1G is a cross-sectional view of another exemplary embodiment of a self-cooling TET system, illustrating a PCM heat accumulation structure 40 g that is disposed externally of ECA 10 ; specifically simultaneously being disposed partially within a volume defined by a portion of the ECA housing covering a primary coil of the ECA, being disposed to partially surround a portion of an exterior of the ECA, and being disposed between the ECA and the patient. This exemplary embodiment combines the elements of the exemplary embodiments illustrated in FIGS. 1C and 1D . If PCM heat accumulation structure 40 g is to be reserved for absorbing thermal energy from implanted medical device 80 (as opposed to also absorbing thermal energy from ECA 10 ), the techniques discussed above can be used to thermally isolate the ECA from the PCM. If PCM heat accumulation structure 40 g is instead intended to absorb thermal energy from ECA 10 , then portions 46 g of enclosure 48 g can be fabricated using a thermally conductive material.
[0057] Additionally, if the thermal capacity of PCM 45 is to be exclusively dedicated to absorbing thermal energy from ECA 10 , then either portion 43 of enclosure 40 g (the portion proximate dermal layer 50 ) can be formed of a thermally insulating material, or an air gap can be incorporated between PCM enclosure 48 g and dermal layer 50 .
[0058] FIG. 1H shows an exemplary toroidal shaped external ECA housing 10 a including a hollow central volume. A PCM heat accumulation structure can be configured to fit partially or entirely, within the hollow central volume, to partially or entirely encircle an outer periphery of ECA housing 10 a , and/or combinations thereof.
[0059] FIG. 2 is a cross-sectional view of the embodiment of FIG. 1F , in which an ECA 10 b includes a cooling fan 90 disposed to remove thermal energy accumulated by PCM 45 . The fan serves to transport ambient air 95 over the PCM so as to transport some heat away from the PCM, as the PCM is absorbing heat from the patient's tissue. Transporting some heat away from the PCM will increase the effective heat absorption capacity of the PCM, enabling increased cooling capacity. This fan configuration can also be implemented in any of the PCM heat accumulation structure embodiments illustrated in FIGS. 1A , 1 B, 1 C, 1 D, 1 E, and 1 G.
[0060] FIG. 3 schematically illustrates a strap 15 (or harness) that may be attached to a patient to secure ECA 10 and PCM heat accumulation structure 40 in proper position relative to the patient's dermal layer 50 . If desired, the cooling fan 90 of FIG. 2 can be incorporated into the harness, rather than into the ECA. Similar to the fan, the PCM structure may also be incorporated into the strap/harness for the ECA.
[0061] FIG. 4 schematically illustrates an embodiment in which a secondary coil 81 implanted within a patient is spaced apart from an implanted medical device 83 , and one or more conductors 85 couples the secondary coil to implanted medical device 83 . In the embodiments discussed above, the secondary coil disposed to receive energy from the primary induction coil within ECA 10 was considered to be part of implanted medical device 80 . The embodiment of FIG. 4 recognizes that while the secondary coil itself does need to be disposed proximate a location accessible to the ECA, the implanted medical device (or elements of the implanted medical device) can be disposed at other locations, so long as those other elements requiring energy are electrically coupled to the secondary coil. Thus, it should be understood that the concepts disclosed herein apply to embodiments in which the secondary coil is spaced apart from (but electrically coupled to) one or more elements of the implanted medical device.
[0062] FIG. 5A schematically illustrates a top-view of an embodiment in which a primary transmission coil of an external charging unit is contained within its own housing 10 c , which is spaced apart from the other remaining electrical components of the external charging unit contained within a separate housing 10 d , and one or more conductors 12 electrically couples together the components contained in housings 10 c and 10 d. In previously presented embodiments discussed above, the primary transmission coil is configured to transmit energy to the secondary coil in the implanted medical device, and the additional electrical components in the ECA were considered to be disposed in a common housing. The embodiment of FIG. 5A recognizes that while the primary coil is disposed proximate to the implanted secondary receiving coil, other electrical components of the ECA may be positioned at a different location, so long as those electrical components are connected to the primary coil by one or more electrical conductors. Thus, it should be understood that the concepts disclosed herein apply to embodiments in which the primary coil is spaced apart from (but electrically coupled to) one or more elements electrical elements required by the ECA.
[0063] FIG. 5B schematically illustrates a side-view of FIG. 5A . It should be noted that PCM heat accumulation structure 40 i is illustrated as being removed from inside a central toroidal volume defined by housing 10 c of the external charging accessory.
[0064] FIGS. 6A and 6B schematically illustrate a TET system 100 that cools the ECA 10 by providing a flow of cooling air that passes through airflow inlets and outlets that are disposed at a distance away from the ECA 10 . As illustrated in FIG. 6A , an alternative strap 115 (or harness), similar to the strap 15 illustrated in FIG. 3 , can be attached to a patient to secure the ECA 10 and the PCM heat accumulation structure 40 in proper position relative to the patient's dermal layer 50 . In the exemplary embodiment of FIG. 6A , the strap 115 has two opposing ends with one strap end 115 a supporting the ECA 10 and the PCM heat accumulation structure 40 and the other strap end 115 b supporting a housing 102 that can support a battery (not shown) that provides power to the ECA 10 via wiring (not shown) extending along the length of the strap 115 to connect the battery to the ECA 10 . The housing 102 at the other strap end 115 b can also support a control interface and display 104 that allows an operator to program and control the operation of the TET system 100 . The housing 102 can also support a venting inlet 106 and venting outlet 108 fluidly communicating with tubing 110 a and 110 b that extend the length of the strap 115 to connect the venting inlet 106 and venting outlet 108 to the ECA 10 to provide a pathway for a flow of cooling air. The venting inlet 106 can fluidly communicate with an end of the tubing 110 a to direct an incoming flow of air from the venting inlet 106 to the opposing end of the tubing 110 a that connects to the ECA 10 to deliver the flow of cooling air to the interior space 21 of the bobbin 20 of the ECA 10 (shown in FIG. 6B ). In an opposite manner, a return flow of the cooling air, warmed after passing through the interior space 21 of the bobbin 20 , exits the ECA 10 and passes through the tubing 110 b to be delivered to the venting outlet 108 . A fan (not shown in FIG. 6A ) can be provided near or at the venting inlet 106 or venting outlet 108 to propel the flow of cooling air through the cooling system defined by the venting inlet 106 , the tubings 110 a and 110 b , and the venting outlet 108 . The fan can also be provided near the ECA 10 , within the interior space 21 of the bobbin 20 as illustrated by the fan 90 in FIG. 6B , or provided adjacent to the interior space where the inlet tubing 110 a meets the interior space of the bobbin 20 . In the embodiment illustrated in FIG. 6A , a single tubing 110 a delivers the flow of cooling air to the ECA 10 and a single tubing 110 b directs the now-warmed flow of cooling air away from the ECA. As can be appreciated, multiple tubes or pathways can be used to direct the flow of cooling air to and from the ECA 10 , such as is shown in FIG. 6B where two tubings 110 b are provided to direct the exit of the now-warmed flow of cooling air away from the ECA 10 . As can also be appreciated, the flow of cooling air can achieve thermal communication and cool the ECA 10 by passing along the exterior of the coil 30 wrapped about the bobbin 20 or along another thermally effective pathway through or adjacent to the ECA 10 . As can be further appreciated, the exit of the flow of cooling air from the ECA 10 can be immediately vented out of the cooling system by placing the venting outlet 108 at the strap end 115 a with the venting outlet 108 positioned on or near the ECA 10 .
[0065] FIGS. 7A and 7B illustrate an alternative cooling system that delivers a flow of liquid to resupply the material within the PCM heat accumulation structure 240 as the material within the PCM heat accumulation structure 240 undergoes a phase change to produce a gas. FIG. 7A schematically illustrates a TET system 200 having an alternative strap 215 (or harness) similar to the strap 15 illustrated in FIG. 3 . The strap 215 can be attached to a patient to secure the ECA 10 and the PCM heat accumulation structure 240 in proper position relative to the patient's dermal layer 50 . In the exemplary embodiment of FIG. 7A , the strap 215 has two opposing ends with one strap end 215 a supporting the ECA 10 and the PCM heat accumulation structure 240 and the other strap end 215 b supporting a housing 202 that can support a battery (not shown) that provides power to the ECA 10 via wiring (not shown) extending along the length of the strap 215 to connect the battery to the ECA 10 . The housing 202 at the other strap end 215 b can also support a control interface and display 204 that allows an operator to program and control the operation of the TET system 200 . The housing 202 can also support an internal reservoir (not shown) with a reservoir inlet port 205 that allows refilling of the internal reservoir as needed. The internal reservoir can fluidly communicate with tubing 210 a which extends the length of the strap 215 to connect the internal reservoir to the PCM heat accumulation structure 240 to provide a pathway for a flow of cooling liquid. The tubing 210 a can direct the flow of cooling liquid to an interior of the PCM heat accumulation structure 240 to cool the ECA 10 (as shown in FIG. 6B ). After cooling the ECA 10 , and undergoing a phase change, the cooling liquid changes to a gas that is directed out of the PCM heat accumulation structure 240 to tubing 210 b which directs the gas to a terminal end of the tubing 210 b at a venting outlet 208 . As illustrated in FIG. 7B , the PCM heat accumulation structure 240 can be configured to have an internal partition 241 that directs the flow along a tortuous pathway through the interior PCM heat accumulation structure 240 to maximize the cooling provided to the ECA 10 . In the exemplary embodiment of FIG. 7B , the tortuous pathway has the inflowing liquid enter an inner portion of the PCM heat accumulation structure 240 that is adjacent to the ECA 10 , with the flow compelled to flow along a semi-circular path about the PCM heat accumulation structure 240 until reaching vent holes 242 that allow the flow to move to an outer portion of the PCM heat accumulation structure 240 surrounding the inner portion, with the tortuos pathway continuing as the flow traverses a semi-circular pathway back to exit the PCM heat accumulation structure 240 via the tubing 210 b for venting at the venting outlet 208 . As can be appreciated, a fan (not shown in FIGS. 7A or 7 B) can be provided near the internal reservoir or near or within the tortuous pathway within the PCM heat accumulation structure 240 to propel the flow of liquid or gas through the cooling system defined by the internal reservoir, the tubings 210 a and 210 b , the PCM heat accumulation structure 240 , and the venting outlet 208 . In the embodiment illustrated in FIG. 7A , a single tubing 210 a delivers the flow of cooling liquid to the PCM heat accumulation structure 240 and a single tubing 210 b directs the now-warmed flow of cooling gas away from the PCM heat accumulation structure 240 . As can be appreciated, multiple tubes or pathways can be used to direct the flows to and from the PCM heat accumulation structure 240 . As can also be appreciated, the flow passing through the PCM heat accumulation structure 240 achieve thermal communication and cool the ECA 10 by passing through a variety of tortuous pathways through the PCM heat accumulation structure 240 or by passing through a direct non-tortuous pathway through the PCM heat accumulation structure 240 . As can be further appreciated, the exit of the flow of cooling gas from the PCM heat accumulation structure 240 can be immediately vented out of the cooling system by placing the venting outlet 208 at the strap end 215 a with the venting outlet 208 positioned on or near the PCM heat accumulation structure 240 .
[0066] FIG. 8 is a cross-sectional view of an alternate cooling system in accordance with embodiments of the present invention. In this embodiment, an ECA 10 c includes a cooling fan 90 disposed to remove thermal energy, similar to the embodiment illustrated in FIG. 2 . However, in FIG. 8 , the ECA 10 c comprises a housing 82 with a larger diameter than the housing shown in FIG. 2 . This expanded housing and additional vents 84 allows for more efficient use of convection air flow to cool the primary coil 30 of the ECA 10 c. The PCM 45 contained in the enclosure may be optionally included or omitted in various embodiments.
[0067] Referring to the exemplary embodiment illustrated in FIG. 8 , the additional vents and the inclusion of a spacing between the exterior of the coil and the inside of the expanded housing advantageously allows the cooling fluid to simultaneously circulate about the interior and exterior of the coil. As can be appreciated, the flow of the cooling fluid can be directed to first pass through the interior of the coil and then be directed to change direction to pass over the exterior of the coil. Alternatively, the cooling fluid can be directed to split and simultaneously flow in the same direction over the interior and exterior of the coil.
[0068] In one or more of the embodiments discussed above, the PCM structure can be used as an interlock, so users cannot charge an implanted device without such a PCM structure in place. Such interlocks can be implemented by incorporating a switch into a portion of the ECA, where the switch is actuated when the PCM structure is attached to the ECA.
[0069] Yet another modification which can be made to any of the embodiments discussed herein involves the incorporation of a thermal monitoring capability into a TET charging system, where the thermal monitoring capability is employed to determine when a spent PCM structure (i.e., a structure whose PCM is approaching or has reached its heat capacity, and is about to or has changed state) and should be replaced with a fresh PCM structure (i.e., a structure whose PCM is below the phase change temperature, and is thus ready to absorb thermal energy). Such thermal monitoring can be applied to one or more of the PCM material, the ECA, or tissue proximate the implanted device. Many different types of sensors, including but not limited to infrared thermometers and thermocouples, can be used for such thermal monitoring purposes. Where a temperature of the PCM material is being monitored, note that the PCM will gradually increase in temperature until the temperature required for the phase change is met, will then maintain a generally constant temperature during the phase change, and will experience temperature increases again after the phase change. A rise in temperature after a plateau is thus indicative that a PCM is spent. Where a temperature of the ECA or tissue is being monitored, note that once a normal operating temperature has been reached, the heat absorbing capacity of the PCM will enable the ECA/tissue to maintain a generally constant temperature until the PCM is spent. Thus, a rise in temperature after a plateau is also indicative that a PCM is spent.
[0070] It should also be recognized that while the above description has emphasized that the secondary coil is used to charge a rechargeable energy source (e.g. a rechargeable battery or capacitor), that the concepts disclosed herein can also be employed in connection with implanted medical devices that include no such rechargeable energy source. Such implanted medical devices would only be energized when the ECA is providing energy to the secondary coil, however, such an embodiment would likely be used where the implanted medical device was used infrequently.
[0071] Some of the exemplary embodiments discussed above have emphasized PCM materials that act as a heat sink as the material transitions from a solid to a liquid. It should be recognized that materials transitioning from a liquid to a gas or vapor, or from a solid to a gas or vapor, could also be used as a heat sink, so long as the temperature associated with the phase change was in the desired range. Such materials function as a heat sink due to the latent heat of vaporization, rather than the latent heat of fusion. As can be appreciated, a PCM that undergoes a phase change can produce an increase in volume or pressure (e.g., in a phase change from a liquid to a solid, a solid to a gas, or a liquid to a gas) and any container housing such a PCM must be designed to take into account the increased volumes and pressures that would accompany such a phase change. In any of the embodiments described herein, a vent or pressure-relief valve can be installed in the container housing a PCM to relieve increases in pressure or volume. Likewise, the container housing a PCM can be configured to have an expanding portion of the container that expands to compensate for increases in pressure or volume.
[0072] While the embodiments discussed above have focused on thermally coupling the PCM to the patient's tissue, it should be noted that the concepts disclosed herein also encompass embodiments wherein the PCM is thermally isolated from the patient's tissue, such that the PCM is used as a heat sink only for the ECA. Such an embodiment will prevent thermal energy from the ECA from being absorbed into the patient's tissue, thus enabling the tissue to safely absorb more thermal energy from the implanted medical device during charging or supply of electrical power to the implanted device.
[0073] Although the concepts disclosed herein have been described in connection with the preferred form of practicing them and modifications thereto, those of ordinary skill in the art will understand that many other modifications can be made thereto within the scope of the claims that follow. Accordingly, it is not intended that the scope of these concepts in any way be limited by the above description, but instead be determined entirely by reference to the claims that follow.
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A method and system for management of thermal energy produced during transcutaneous energy transmission to provide power to energize implanted medical devices. A phase changing material (PCM) acts as a heat sink to absorb thermal energy generated during the energy transfer process. The PCM can be thermally coupled to tissue proximate to an implanted medical device, enabling heat generated within the implantable device to be absorbed. The generation of heat during the energy transfer process is primarily caused by eddy currents induced in the implantable device by the magnetic flux produced by the energy transfer system. The PCM can also be used to absorb heat generated by the device producing the magnetic flux that is used to transcutaneously transfer electrical power to recharge a rechargeable power source or energize the implanted medical device.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/460,767, filed Apr. 30, 2012.
[0002] U.S. patent application Ser. No. 13/460,767 claims benefit of U.S. provisional patent application Ser. No. 61/481,220, filed May 1, 2011, both of which applications are incorporated herein in their entireties by this reference thereto.
BACKGROUND
[0003] The following is a tabulation of some of the prior art that appears relevant. Issued U.S. patents:
[0000]
TABLE 1
1,275,507
1918 Aug. 13
Vuilleumier
4,483,143
1984 Nov. 20
Corey
4,490,974
1985 Jan. 1
Colegate
Non-Patent Literature Documents
[0004] The Regenerator and the Stirling Engine, by Allan J. Organ, (Wiley; edition, Mar. 14, 1997, 624 pages); and
Kongtragool B., Wongwises S., Thermodynamic analysis of a Stirling engine including dead volumes of hot space, cold space and regenerator, Renewable Energy, 31 (2006) 345-359.
[0006] Heat pumps and engines of the Stirling and Vuilleumier variety consist of at least two working fluid spaces, usually cylinders, that are held at different temperatures. The working fluid is fully contained within the system and displaced between the spaces either by a piston in each of the cylinders or by one or more separate displacers. In all but the simplest designs, the working fluid passes through a regenerator each time the working fluid is transferred between the spaces, giving up or taking on heat that is stored in the regenerator, from the last cycle, thereby increasing the efficiency of the system. These devices are well known it the art and are described thoroughly in the book The Regenerator and the Stirling Engine, by Allan J. Organ, (Wiley; 1 edition, Mar. 14, 1997, 624 pages). These systems are usually designed with high cycle rates in mind, often in the range of 1200 revolutions or cycles per minute, and therefore have comparatively open passages for fluid flow in order to avoid frictional losses. This approach allows for a high number of power cycles in a short period of time, thereby causing a mechanism of a given size and heat input to pay its way as efficiently as practicable, with regard to the fuel cost, maintenance cost, and the initial construction cost. The continuous motion of the device is usually ensured by phasing the mechanical action within the two spaces, usually at nearly 90 degrees to each other and including a flywheel or other harmonic means of inertially bringing about the next cycle.
[0007] Increased systemic ‘dead volume’, as described in a paper by B. Kongtragool et al (B. Kongtragool, S. Wongwises/Renewable Energy 31 (2006) 345-359), limits the net work and efficiency of these systems by allowing a significant portion of the compression or expansion of the working fluid to occur in that systemic dead volume rather than specifically in the chamber, cylinder or heat transfer area that was designed to do useful work. A change in working fluid pressure taking place within the regenerator or other ducting of a Stirling or Vuilleumier cycle device, will cause a temperature change in that portion of the working fluid, but not allow that temperature change to be communicated to a heat exchanging head in order to do useful work during that particular cycle. While heat energy that changes the pressure of the working fluid in portions of the system other than at the open end of the active cylinder is not necessarily lost, it is not made useful during that particular cycle. The useful work performed during a particular cycle is proportional to the change in pressure within the total system as well as the proportion of the working fluid that is in contact with the heat transfer surface of the open end of the active cylinder. Devices of this variety are notoriously difficult to scale up into larger, more powerful devices because of the difficulty in predicting the loss in power and efficiency due to the increased dead volume and corresponding reduction in the percentage of working fluid that is in contact with the heat transfer area that can make use of the working fluid's temperature difference. Power densities and efficiencies of larger systems usually require increased complexity and cost in order to properly balance dead volume against the system's resistance to the flow of working fluid.
[0008] Materials used for the construction of heat pumps of this variety are chosen for their strength, durability and heat retention and conduction properties as well as their tendency to resist oxidation or otherwise react to the working fluid at the temperatures and pressures of any particular device. Solid conductors, heat sinks and regenerator materials range from stainless steel to cotton and are configured geometrically to transfer heat energy as advantageously as possible for a given configuration while minimizing resistance to the flow of working fluid. Regenerator materials are usually configured into wire matrices that allow for maximal contact of the working fluid with a heat retaining material that will withstand repeated cycling of temperature and flow direction. Stacked screens or other geometric matrices of stainless steel, wire, or pellets are commonly used with the intent of maximizing the heat transfer properties to and from the working fluid without excessively conducting heat between the elements of the regenerator. This is to avoid losses due to systemic longitudinal heat flow within the matrix.
[0009] The objects of the invention are as follows:
To produce more work per unit volume during each cycle of a Stirling or Vuilleumier cycle device. To produce a device that is predictably scalable into larger, more powerful devices, without an unreasonable loss of power or efficiency. To avoid wasting the power invested in the compression and expansion cycles of a Stirling or Vuilleumier cycle system by reducing the dead volume in various areas. In particular, to reduce dead volume in the regenerator to zero, or nearly zero, by placing it within the displacer/regenerator space and causing interstitial spaces of the heat regenerating elements to be fully purged of the working fluid during certain portions of each cycle by collapsing the nesting elements together, thereby forcing all working fluid into the most advantageously conductive portion of the active cylinder at that particular phase and time. To reduce dead volume within the heat transfer areas by providing increased surface areas in each compression or expansion chamber that can be fully purged of the working fluid during each cycle by nesting tapered pins of the heated and cooling heads within tapered holes of the end plates of the displacer/regenerator stack. To allow the end plates of the displacer/regenerator stack to remain in contact with the heated or cooling head while the device opens other areas of the system, thereby transferring heat to or from the end plates' surfaces, making the heating or cooling of the fluid more rapid during the next cycle. To provide for the flexible timing of cycles and phases without requiring the continuous motion of a mechanical linkage that operates at a particular, predetermined frequency or phase angle. To provide for the timing of cycles and phases in a manner that allows for a dwell period during any particular time in the cycle, in order to allow useful work to be accomplished as fully as practicable before proceeding to the next phase of the cycle. To provide for the timing of cycles and phases in a manner that allows for a dwell period during any particular time in the cycle, in order to allow the transfer of heat to or from the head, piston or regenerator elements, to be accomplished as fully as advantageous at any particular temperature, pressure, flow rate and cycle rate before proceeding to the next phase of the cycle. To provide for the timing of cycles and phases in a manner that allows any given chamber to open or close as fully as advantageous before any other chamber begins to open or close. To provide for timing of cycles and phases that allows any given chamber to begin to open or close at the most advantageous time in any given cycle, based on an algorithm that optimizes the timing according to the temperature, pressure, flow rate, cycle rate and positions of various portions of the system, according to sensors in those areas. To reduce fluid frictional losses by cycling at a rate no greater than necessary to accomplish the presently assigned task, thereby allowing the minimization of working fluid passageway cross sectional areas and their associated dead volumes, whether inside or outside the regenerator. To provide for timing of cycles and phases without requiring the addition of dead volume to accommodate the timing mechanism. To reduce mechanical friction and working fluid pressure losses by avoiding the penetration of the sealed system by mechanical shafts or linkages To reduce longitudinal heat conduction through the regenerator elements by interleaving the regenerator elements with insulating material of similar geometry. To prevent eddy currents from forming within the regenerator matrix by purging all working fluid from the matrix during each cycle, thereby stopping the flow of the working fluid at least momentarily, during at least a portion of each cycle. To allow the pressure changes in one, heated/driving system, to be communicated to, and used directly in, another similar driven/cooling system, in order to avoid losses associated with the transformation of energy to and from its various forms, such as thermal, electrical, mechanical and chemical. To allow for multiple heat sources for the heating of the driving portion of the device, including solar thermal heating as well as electrical, gas or waste heat from a process, building or vehicle. To allow for alternative power sources for the mechanism drive, including self-generated internal pressures, an electric motor or solenoid, or a separate heat engine that is also powered by solar thermal, natural gas or waste heat. To allow waste heat from the warm side of both driving and driven cylinders to be reused for other purposes, such as water heating. To allow for the connection of this system's data processing unit to the system control of an associated building or process, to better integrate all systems efficiently. To allow for the operation of the system as a building heating unit by reversing the phase of the second, driven cylinder in relation to the first. To allow for excess power to be used as mechanical power to generate electricity or pump liquid by driving a piston or pistons with the pressure from the driving cylinder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 shows a schematic diagram of the device configured as a heat pump.
[0029] FIG. 2 shows a schematic diagram of the device configured as an engine.
[0030] FIG. 3 shows the driving/heated head and the mating end plate of the displacer/regenerator stack with the individual displacer/regenerator layers below as they are stacked in the cylinder.
[0031] FIG. 4 shows two elements of the displacer/regenerator stack, configured in the form of grids constructed of trapezoidal prisms.
[0032] FIG. 5 shows four elements of the displacer/regenerator stack, configured in the form of grids of trapezoidal prisms, partially nested, but with some interstitial space between them.
[0033] FIG. 6 shows the geometric edge detail of two displacer/regenerator layers nested partially.
[0034] FIG. 7 shows one element of the displacer/regenerator stack with a circumferential skirt that provides a smooth surface to bear against the inner surface of the cylinder wall. This skirt feature is eliminated in other views in order to show the geometry of the layers more clearly.
[0035] FIG. 8 shows a shaded edge detail of four displacer/regenerator elements expanded to better show the nesting geometry of the trapezoidal prism grids.
[0036] FIG. 9 shows the upper surface geometry of another embodiment of one of the nesting elements of the displacer/regenerator in the form of a sheet having truncated conical holes and matching truncated conical bumps in a square pattern. A recess that holds a wave spring washer is also shown.
[0037] FIG. 10 shows the upper surface geometry of another embodiment of one of the nesting elements of the regenerator in the form of a sheet having truncated conical holes and matching truncated conical bumps in a triangular pattern.
[0038] FIGS. 11 , 12 and 13 show another embodiment of one of the nesting elements of the displacer/regenerator in the form of square cupolas and holes matching that shape in a square pattern.
[0039] FIG. 14 shows a diagram of the electronic control system.
[0040] FIGS. 15 and 16 show the nesting of one of the end plates into one of the heads.
[0041] FIG. 17 shows an exploded view of the assembly of the heated head and the plate and adjacent layers into the cylinder, from another angle.
DESCRIPTION
[0042] This invention relates to heat engines and Stirling cycle devices, and more particularly to heat driven duplex Stirling coolers and Vuilleumier heat pumps having regenerators. Existing Stirling cycle engines and heat pumps contain dead volumes, primarily in the heat exchanger and regenerator areas to provide space through which the working fluid may pass on its way to another chamber, while gaining or releasing heat energy. The presence of excess dead volume is undesirable because it dilutes and lowers the extremity of pressure changes in areas of the device that are capable of accomplishing useful work during a given cycle. (Kongtragool B., Wongwises S., Thermodynamic analysis of a Stirling engine including dead volumes of hot space, cold space and regenerator, Renewable Energy, 31 (2006) 345-359) Typically the design of a Stirling cycle device must be a balance of surface areas and volumes, in open areas of the device, to allow for sufficient heat transfer without creating either excessive losses due to restriction of fluid flow or excessive dead volumes in these areas. It has historically been difficult to eliminate much of the dead volume within these fixed, open areas. A further problem associated with regenerators of fixed volume is that standing eddy currents can arise that act as short circuits to the heat cycle and rob the regenerator of its contribution to efficiency by allowing cooled fluid to travel one direction within one area and hot fluid to travel in the opposite direction within another area. This defeats the heat recovery purpose of the regenerator in these areas.
[0043] The present invention involves Stirling cycle related devices, particularly a heat pump that comprises two cylinders. Referring to FIG. 1 , a first, driving/heated cylinder ( 1 ) is heated on one end, through a heated head ( 2 ), and cooled on the other end, through a cooled head ( 3 ). A displacer/regenerator stack ( 4 ), comprising two end plates ( 5 ) and a plurality of nesting inner displacer/regenerator layers ( 6 ), is expanded and collapsed alternately toward opposite ends of the heated cylinder ( 1 ) by one of two timing/actuation means ( 17 ), thereby creating an alternating pressure within the heated cylinder ( 1 ). A second, similar cooling cylinder ( 7 ), is driven by alternating pressure of the first, driving/heated cylinder ( 1 ), and cools a specific living space ( 8 ), or refrigerating compartment, by using the alternating pressure from the driving/heated cylinder ( 1 ) to pump heat from the space to be cooled. The thermal pressurization of working fluid in the heat exchange cavity ( 9 ) of the driving/heated cylinder is used directly, to compress working fluid in the warm end heat exchange cavity ( 10 ) of the driven/cooling cylinder ( 7 ), thereby driving heat off that end. The driven/cooling cylinder ( 7 ) also contains a displacer/regenerator stack ( 11 ) similar to that in the driving/heated cylinder ( 1 ). Displacer/regenerator stacks ( 4 , 11 ) in each of the cylinders, each comprise two end plates ( 5 ) that capture a plurality of nesting displacer/regenerator layers ( 6 ) that are constructed from, or plated with, a heat retaining material such as a metal. Each of the end plates and layers are constructed such that that when the stack is forced together, all interstitial spaces are closed, thereby eliminating what would otherwise be dead volume. This leaves space in only one of each cylinder's heat exchange cavities that usefully transfers heat between the working fluid and a head. Heat in the working fluid is thereby recovered, stored, and regenerated during a subsequent phase of a given cycle without the dilution of compression and the associated loss of power that would usually occur due to the dead volumes that would be left open in traditional heat exchanger passageways and static, porous regenerators.
[0044] Each cylinder assembly ( 1 , 7 ) comprises a cylindrical container with a heat conducting head ( 2 , 3 , 12 , 13 ) on each end. In the preferred embodiment, the heated head ( 2 ) of the driving/heated cylinder ( 1 ) may accommodate external components appropriate to take on heat from radiant heat sources such as the sun, including reflectors that collect and concentrate the radiant heat energy, and insulating windows that prevent radiant and conductive losses. The head may also have geometry to receive supplemental heat from other sources such as hot liquid, a flame, or an electrically heated element for operation during periods that lack sufficient direct solar radiation. The other cylinder heads may have appropriate heat exchange geometry such as finned surfaces ( 14 ), adequate to transfer heat to or from the ambient environment in their immediate areas. The ambient air or other medium may be driven across the fins of these heads by fans or pumps, depending on the necessity to do so at the time.
[0045] An end plate ( 5 ) at each end of each displacer/regenerator stack ( 4 , 11 ), is a piece of heat conductive material that is significantly thicker than the other layers of the stack. It is in contact with a timing/actuation means ( 17 ) that compresses the stack from either end of the associated cylinder at the correct time in the cycle. Each of these end plates ( 5 ) has a plurality of tapered holes ( 15 ). Each of these holes surrounds a similarly shaped pin ( 16 ) that protrudes from its adjacent head, increasing the surface area of the heat exchanger cavity ( 9 , 10 ) compared to its volume when open. The tapered holes ( 15 ) also allow the pins ( 16 ) to protrude through each end plate ( 5 ). The inner side of the end plate that is in contact with the first thin displacer/regenerator layer on that end, is shaped such that it nests against the first displacer/regenerator layer as if it were another layer itself. The ends of the associated head's heat exchanger pins that protrude through the holes of the end plate ( 5 ) are likewise formed to nest with the next thin displacer/regenerator layer. This may be accomplished by nesting a plate ( 5 ) against its associated head and machining the profile of the subsequent layer into the mated head-plate assembly, thereby ensuring proper nesting of all three parts. This allows communication of working fluid from within the regenerator stack to the head's heat exchange area when the timing/actuation means compresses the stack from one end, and allows the working fluid back into the stack when the stack is no longer compressed by the timing/actuating means ( 17 ). The stack is expanded by a spring means that may be the shape preloading of the individual layer elements into a saddle shape similar to the geometry of a potato chip. Another spring means that is easily accommodated by this configuration includes wave spring washers ( 27 ) that nest within circular recesses ( 28 ) in each layer. The timing/actuation means ( 17 ) works against the spring means to compress the head/plate/regenerator engagement to one end of the cylinder, thereby eliminating nearly all dead volume in that area, at that time, and forcing nearly all working fluid into the open area at the other end of the cylinder.
[0046] The inner displacer/regenerator layers ( 6 ) comprise disks of heat retaining materials that are thin enough to take on, and give up heat readily but are not so fragile that they can be damaged by extended exposure to heat and slight bending. An overall thickness of two millimeters is practical in many metals, giving each grid element a cross sectional area of approximately one square millimeter in the trapezoidal prism configuration that is most clearly seen in FIGS. 4 through 8 . Appropriate materials for the construction of these layers include those that would be suitable for high temperature spring materials such as; copper alloys, brass alloys, bronze alloys, stainless steel alloys, titanium alloys, nickel-chromium alloys such as INCONEL, nickel-copper alloys such as MONEL, as well as aluminum alloys, high temperature plastics, fiber reinforced plastics, ceramics, and graphenes. Layers of less conductive materials, such as high temperature plastics, may be interleaved between the conductive layers to offer insulation between them in order to minimize the longitudinal flow of heat through the solid material of the stack while it is nested tightly. High temperature plastics may also be plated with materials of higher conductivity, such as copper or aluminum in order to retain heat at the surface of the layer without drawing heat so far into the structure of the material that it cannot be made useful during the next cycle.
[0047] Each head contains a timing/actuation means ( 17 ). When any constraining force from one of the timing/actuation means is released, the stack in that cylinder expands, due to pressure exerted between the layers by the separate springs ( 27 ) or integral spring properties or features formed into each layer. The stack then fills the cylinder between the two ends of the cylinder, allowing the working fluid to flow back into the interstices of the displacer/regenerator stack. Each time the displacer/regenerator stack is purged or refilled, the flow is stopped, thereby preventing ongoing eddy currents from forming.
[0048] The timing/actuation means ( 17 ) comprises shaft driven cams, sliding plates, memory wire springs, or solenoids that contact each end plate and, when at rest, fill their respective travel volumes, thereby avoiding the creation of dead volume in spaces other than working fluid areas that are in use at a particular time. In one preferred embodiment, the timing/actuation means comprise cams that are driven by shafts that each pass through a seal on each head. In another preferred embodiment, there is provided a timing means, in each head, that is magnetically driven from outside a hermetically sealed system, thereby reducing mechanical losses associated with running seals around drive shafts, and further reducing the loss of working fluids such as helium. In relatively low temperature applications, solenoids may be used within the cylinder. In some rudimentary, low cost embodiments, memory wire such as nickel-titanium alloy may be used to actuate a cycle at the proper time, when the programmed reaction temperature of the memory wire is attained, thereby changing the state of the memory wire to spring mode rather than passive mode and thereby creating a compressing end force on the stack of displacer/regenerator elements.
[0049] In the preferred embodiment, the cycles of the system are actuated by solenoids or linkages which in turn are controlled by an electronic control system ( 18 ) according to algorithms that ensure adequate time for heat transfer in any particular space depending on the particular temperatures and pressures in the system at that particular time. There is no predetermined phase angle between the components as is usually encountered in devices of this variety that are driven by a predetermined harmonic or phased rotational motion.
[0050] The electronic control system ( 18 ) causes each of the timing/actuation means ( 17 ) to bring about a sequence of actions, in the proper order, at the appropriate time and actuation speed to gain efficient performance, at any given set of sensed temperatures and pressures. Appropriate dwell times, between actions, allow for adequate and efficient heat transfer. The effect of the sequence of commands from the electronic control system ( 18 ) to the timing/actuation means ( 17 ) is to;
[0000] 1. Push the displacer/regenerator stack ( 11 ) away from the warm head ( 12 ) of the driven/cooling cylinder ( 7 ), opening a heat exchange cavity ( 10 ) to receive pressurization. 2. Push the displacer/regenerator stack ( 4 ) away from the heated head ( 2 ) of the driving/heated cylinder ( 1 ), opening a heat exchange cavity ( 10 ) to accommodate working fluid that will be heated to create pressurization. (This heats working fluid that has come in contact with the heated head and the holes of the end plate adjacent to the headed head, pressurizing the system, causing heat to be driven from the warm head ( 12 ) of the driven/cooling cylinder ( 7 ).) 3. Relax both displacer/regenerator stacks ( 4 , 11 ), filling both cylinders with expanded displacer/regenerator stacks and the interstitial spaces between regenerator elements, thereby drawing the working fluid into the interstices of the displacer/regenerator stacks. 4. Push displacer/regenerator stack ( 11 ) away from cooling head ( 13 ) of the driven/cooling cylinder ( 7 ), opening a space that will allow working fluid in that space to experience de-pressurization in order to take on heat from the living space ( 8 ) or a cooling appliance. 5. Push the displacer/regenerator stack away from cooled head ( 3 ) of the driving/heated cylinder ( 1 ), opening a space to produce the de-pressurization that will be used to cool the cooling head ( 13 ) of the driven/cooling cylinder ( 7 ). (The cylinders now communicate their pressures. The hot cylinder cools the working fluid that has come in contact with its cooled head, de-pressurizing the system, causing heat to be pulled from the cooling head ( 13 ) of the cooling cylinder ( 7 ), thereby cooling the living space ( 8 ) or cooling appliance.) 6. Relax both displacer/regenerator stacks ( 4 , 11 ), filling both cylinders with expanded displacer/regenerator elements, thereby drawing the working fluid into the interstices of the regenerator layers. 7. Repeat cycles 1-6 while adjusting for any changes in temperatures, pressures and load.
[0051] Referring now to FIG. 2 , the heated/driving cylinder ( 1 ) is shown schematically driving a motor rather than a heat pump. The driving/heated cylinder charges two tanks ( 19 ). One is pressurized and the other is depressurized through the use of two check valves ( 20 ). A pressure motor ( 21 ), of any appropriate variety, is driven by the pressure difference between the tanks. The motor's speed is controlled by valve ( 22 ), which may be driven by cam, solenoid, governor or other means. Appropriate tanks, valves and pressure engines are well known in the art.
[0052] Referring now to FIGS. 3 and 4 , two layers ( 6 a , 6 b ) of a displacer/regenerator stack ( 4 , 11 ) are shown in a position further apart than they would normally occupy in the assembly. A plurality of trapezoidal prisms ( 23 ) make up each side of each layer. The prisms on one side of a layer are oriented at 90 degrees to the prisms on the other side, leaving square openings through which working fluid will pass during operation. In low quantities, these layers are manufactured by machining grooves half way through a thermally conductive material of a certain thickness, and then turning the layer over and machining similar grooves on the other side, at right angles to the grooves on the first side, half way through the material, leaving the square openings when the tool breaks through into the grooves of the first side. These layers can also be made by other processes such as etching, electroforming, molding, coining, furnace brazing of preformed wire, or sintering from powdered materials.
[0053] Referring now to FIG. 5 , four layers at the displacer/regenerator stack ( 4 , 11 ) are shown in a position of nearly full engagement. The trapezoidal prisms of any given layer are occupying the spaces between the trapezoidal prisms on the adjacent layer. Working fluid continues to flow through the matrix until the nesting layers are fully engaged. At full engagement, flow of the working fluid stops, except for minor flow due to some continuing pressure changes and slight leakage.
[0054] Referring now to FIG. 6 , a detail of two layers is shown. As in most other views, no outer ring, skirt or flange is shown for purposes of clarity.
[0055] Referring now to FIG. 7 ; In production devices, each layer ( 6 ) has a circumferential skirt ( 24 ) that is half as thick as the overall thickness of the layer itself, for the purpose of protecting the ends of the individual prisms, or other geometry, and providing a smooth surface to bear against the inner surface of the cylinder wall. This skirt is also an area that can contain the spring means for the separation of the layers when the timing/actuation means ( 17 ) is relaxed.
[0056] Referring now to FIG. 8 , four layers are shown exploded apart and shaded to show the nesting geometry. Again the circumferential skirt is eliminated to better show the nesting geometry.
[0057] Referring now to FIG. 9 , the partial surface of another displacer/regenerator layer geometry is shown that comprises truncated conical bumps ( 25 ) that are oriented in a square pattern. Conical holes ( 26 ) on the lower surface of layers of this embodiment accommodate similar bumps on the top of the adjacent layer below, allowing for working fluid flow until fully engaged, at which time all working fluid is purged from the interstices of the stack. A wave spring washer ( 27 ) is shown in a circular recess ( 28 ). This is one means of separating the layers when the timing/actuation means releases pressure on the stack.
[0058] Referring now to FIG. 10 , a similar geometry is shown depicting truncated conical bumps and holes in a triangular pattern.
[0059] Referring now to FIG. 11 , a similar geometry is shown in which the bumps and holes are in the form of square cupolas ( 29 ), and holes ( 30 ) matching that shape, in an offset square pattern. The black areas depict the open areas that will be plugged by the tops of the square cupolas that reside on the adjacent layer below and rise into the square cupola shaped holes in the far side of the visible part.
[0060] Referring now to FIG. 12 , a cross section of the square cupola geometry is shown as cut through the section A-A in FIG. 11 .
[0061] Referring now to FIG. 13 , an isometric view of the square cupola geometry is shown.
[0062] Other geometries may be used such as sheets of nesting louvers. The requirement is that the geometry of the top side of one layer fully fills the complementary geometry of the bottom side of the adjacent layer leaving holes that allow working fluid to flow through the stack until full engagement of the nesting layers is complete.
[0063] Referring now to FIG. 14 , a diagram of the electronic control system ( 18 ) is shown in which a central processing unit controls the timing/actuation means. Times and rates of actuation are calculated for optimum performance based upon data from temperature and pressure sensors mounted in various areas of the system and in the ambient environment. The history of operation is recorded regarding time, date, load requirement, and previous actions used to meet those needs. This data is used for efficiency decisions made by the CPU and to aid in troubleshooting and reprogramming by service personnel.
[0064] In FIGS. 15 and 16 the head ( 2 ) and plate ( 5 ) are shown, first apart in FIG. 15 , and then fully nested in FIG. 16 . The continuous grooves formed by the profile of the ends of the tapered pins protruding through the similarly shaped surface of the plate will fully nest with the next thin layer ( 6 ) of the stack. FIG. 17 offers an exploded view of the heated head side of the plate, showing the other side of the holes in the plate that nest with the pins in the head.
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A method and apparatus that reduces the dead volume in a heat engine or heat pump, such as a duplex Stirling or Vuilleumier cycle device, by nesting the components of the displacer and regenerator such that nearly all working fluid is purged from the interstices of the regenerator elements and all other working fluid spaces that are not involved in doing useful work at each portion of the cycle. Particularly, a more scalable and efficient method and apparatus for providing solar air conditioning or refrigeration by means of a heated cylinder that alternately pressurizes and depressurizes a separate cooling cylinder by directly transferring thermally induced pressure changes to that cooling cylinder at optimized times in the cycle, under the control of a numerically controlled actuation system that can cycle at a much lower rate than mechanically coupled or harmonically phased systems.
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This is a continuation-in-part of application Ser. No. 08/542,780 filed on Oct. 13, 1995 now U.S. Pat. No. 5,671,961 which is hereby incorporated by reference into this application.
BACKGROUND OF INVENTION
This invention relates generally to devices which grip tubular members, such as drill pipe. More particularly, this invention relates to devices which hold one segment of pipe immobile while another segment of pipe is connected or disconnected. These latter devices are often referred to as back-up power tongs.
Pipe tongs are often employed in the oil and gas industry, particularly to break apart or tighten together threaded pipe connections. It is generally required that one set of pipe tongs grip and rotate one section of pipe and one set of pipe tongs grip and hold stationary the other section of pipe. Modem drilling operations usually employ powered pipe tongs or power tongs. The first set of tongs rotating the pipe are typically referred to simply as power tongs. The second set of tongs holding the pipe stationary are typically referred to as the "back-up" power tongs.
Power tongs generally comprise a body with a passage leading to a central opening such that a section of pipe may be inserted through the passage and positioned in the central opening. Jaw members that are positioned inside the body of the power tongs will selectively move toward and away from the central opening in order to engage and disengage the pipe. The jaw members will usually include dies which will provide the surface actually contacting the pipe. These dies typically have a rough surface or "teeth" to insure the pipe is firmly gripped between the jaws.
Power tongs require a means of maintaining the jaws against the pipe without slippage while considerable rotational forces are applied to the pipe. To accomplish this, the prior art has generally relied on cam surfaces or pistons as a means for closing the jaws against the pipe. It is also preferable to have the jaws contact the pipe around as much of the pipe's circumference as possible. Therefore the closing means is typically positioned around the central opening to grip the pipe from all sides.
U.S. Pat. No 4,649,777 to Buck illustrates three hydraulic cylinders positioned around the central opening. U.S. Pat. No. 4,290,304 shows the positioning era cam surface about the central opening which allows the jaws to tighten as they rotate against the cam surface. While supplying sufficient gripping force, these arrangements result in the closing means being positioned on all sides of the central opening and the power tong body having to virtually enclose the pipe. This inherently leads to the body of the power tong being large and bulky. Incidental to the size of these back-up power tongs is the associated costs from having to use a comparatively large amount of materials in constructing the tongs. Additionally, the greater the size of the tongs, the more limited their use since many applications may require the power tongs operate in areas where there is not sufficient side clearance.
What is needed in the art is improved back-up power tongs which will overcome these disadvantages. The improved back-up tongs should not require that the tong body to virtually enclose the pipe and thus will allow the improved back-up tongs to be considerably smaller. The smaller size of the tongs will allow more versatile use since the tongs can operate in areas with less clearance than prior art tongs. The improved back-up tongs should also be less costly as they will require a considerably smaller amount of material to construct.
Additionally, the improved back-up power tongs will be adaptable to many uses other than breaking pipe in conjunction with conventional power tongs. The present invention also may have application as a gripping device positioned on cranes or other lifting means.
SUMMARY OF INVENTION
Therefore, it is an object of this invention to provide back-up power tongs that are less expensive to build and maintain than hereto known in the art.
It is another object of this invention to provide back-up power tongs that are smaller and can therefore operate in smaller confines than hereto known in the art.
It is still another object of this invention to provide hack-up power tongs that may grip a substantial circumferential portion of a pipe without the body of the back-up tongs having to enclose the pipe.
It is also an object to provide a locking mechanism such that the jaws of the tongs are securely interlocked when the tongs close.
Accordingly the present invention provides back-up power tongs for holding a tubular member against rotation of a connected tubular member. The back-up power tongs comprise a body with a front section for receiving the tubular member and a plurality of jaw members for engaging the tubular member. The jaw members are positioned to form a substantially closed perimeter around the tubular member and at least one of the jaw members is a pivotal jaw, moving in a pivotal path to engage the tubular member.
An alternate embodiment provides two pivoting jaws and a locking mechanism attached to the end of the pivoting jaws such that the pivoting jaws can be securely interlocked.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of the back-up power tongs with the top plate removed and the pivoting jaws in the fully open position.
FIG. 2 is a top view of the back-up power tongs with the top plate removed and the pivoting jaws in a partially closed position.
FIG. 3 is a top view of the back-up power tongs with the top plate removed and the pivoting jaws in a fully closed position.
FIG. 4 is a side view of the back-up power tongs illustrating the back-up power tongs use in conjunction with conventional power tongs.
FIG. 5 is a top view of a second embodiment of the back-up power tongs which has interlocking pivoting jaws.
FIG. 6 is a top view of the back-up tongs with the axial jaw partially cut away in order to illustrate the biasing means between the roller surfaces.
FIG. 7 is a top view of a third embodiment of the back-up power tongs which has cam surfaces with different angle of inclination.
FIG. 8 is a top view of a fourth embodiment of the back-up power tongs which has linear actuators closing the pivoting jaws.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In a preferred embodiment illustrated in FIG. 1, the basic components of improved back-up power tongs 1 comprise a tong body 3, an axial jaw member 5 and two pivoting jaw members 7. Tong body 3 also includes top plate 9 and a bottom plate 10. While top plate 9 has been removed from FIGS. 1-3 in order to show the internal components of back-up tongs 1, top plate 9 and a bottom plate 10 may be seen from the side in FIG. 4. Bolts 30 will be used to secure top plate 9 and a bottom plate 10 to body 3.
FIG. 4 also illustrates how back-up tongs 1 will typically be employed in conjunction with conventional power tongs 129. Both the conventional power tongs 129 and the back-up power tongs 1 will be connected to a common support 126. Back-up power tongs 1 are connected to common support 126 via frame member 125 located on the rear portion of tong body 3. Additionally, legs 127 will extend between conventional power tongs 129 and the back-up power tongs 1 in order to maintain alignment of the tongs. Legs 127 will engage tong body 3 by way of leg flanges 128 and leg apertures 130 (best seen in FIG. 3).
Viewing FIGS. 1-3, it can be seen that the basic function of back-up tongs 1 is to employ axial jaw member 5 and pivoting jaw members 7 to form a substantially closed perimeter around pipe 2. While the gap seen in FIG. 3 existing between the closed pivoting jaw members 7 may vary, those skilled in the are will recognize that the more complete perimeter formed by the jaw members, the greater the gripping capacity of the power tongs.
Viewing FIG. 1, pivoting jaw members 7 will be mounted on the front section 4 of tong body 3 by way of pins 12 which will act as pivot points 13 for pivoting jaws 7. A first end of pivoting jaw 7 will consist of an arcuate segment 7a. Both arcuate segments 7a and axial jaw 5 will have a concave surface 35 with grooves 36 milled therein. Correspondingly, a die 15 is provided having a convex surface with splines 37 milled therein. The splines 37 are milled to matingly slide into the grooves 36 so as to hold die 15 in place. The spline and groove combination provides the necessary torque resistance to the high rotational forces generated when assembling or disassembling pipe segments. Die 15 is held vertically in place by any conventional means such as screw 38 and a lip 35 (not shown) which will allow for easy installation and removal of die 15. Die 15 will have a concave wearing surface 16 which corresponds to the radial curvature of the pipe to be gripped. Wearing surface 16 typically will have a plurality of teeth formed thereon to aid in gripping the pipe. Removable dies 15 may vary in size in order to accommodate different diameters of pipe 2. A more detailed description of die 15 is disclosed in U.S. Pat. No. 4,649,777 to Buck, which is incorporated by reference herein.
Still viewing FIG. 1, a second end of pivoting jaws 7 will consist of rolling surface 7b which operates in conjunction with axial jaw 5 as explained below. Pivoting jaws 7 will have an apertures 11 located between arcuate segment 7a and roller surface 7b. The apertures 11 will in turn pivotally engage pins 12 which will be located at pivot points 13.
Axial jaw 5 will be positioned between and generally to the rear of pivot points 13. As mentioned above, axial jaw 5 also has a arcuate die 15 for engaging the pipe 2. Additionally, each side of axial jaw 5 has an inclined cam surface 18 and locking surface 18a for engaging rolling surfaces 7b of pivoting jaw 7. The operation of inclined cam surface 18 and locking surface 18a will be explained in further detail below.
It can be seen from FIGS. 1-3 that axial jaw 5 is integrally attached to piston and cylinder assembly 20. As most clearly seen in FIG. 2, piston and cylinder assembly 20 generally comprise a cylinder body 23 which is formed with axial jaw 5. Engaging cylinder body 23 will be piston rod 22 having a piston head 21. The end of piston rod 22 opposite piston head 21 is connected to piston backplate 24. Piston backplate 24 is secured in tong body 3 such that operation of piston and cylinder assembly 20 causes cylinder body 23 to move relative to tong body 3 rather than piston rod 22 moving relative to tong body 3.
As best seen in FIG. 2, two sealed cavities are formed between the walls of cylinder body 23 and piston head 21. Forward cavity 25 is formed between the face 26 of piston head 21 and the front walls 27 of cylinder body 23. A central passage 28 is formed through piston rod 22 and communicates with forward cavity 25. Behind piston head 21 is a second cavity, rearward cavity 29 formed by the back of piston head 21 and the rearward portions of cylinder body 23. An offset passage 31 also communicates through piston rod 22, offset and separated from central passage 28. Offset passage 31 is in fluid connection with rearward cavity 29. Both central passage 28 and offset passage 31 are connected to a source of hydraulic fluid which is not shown. A more detailed description of hydraulic piston and cylinder assembly 20 is disclosed in U.S. Pat. No. 4,649,777 to Buck, which is incorporated by reference herein.
In operation, the movement of cylinder body 23 (and thus axial jaw 5) is controlled by the selective filling of cavities 25 or 29. To move jaw 5 forward to engage pipe 2, hydraulic fluid is pumped into forward cavity 25, causing cylinder body 23 to move forward relative to tong body 3. To disengage pipe 2, hydraulic fluid is pumped into rearward cavity 29 while fluid is allowed to simultaneously drain from forward cavity 25. Cylinder body 23 moves rearward relative to tong body 3 and pipe 2 is released.
The movement of axial jaw 5 to engage and disengage pipe 2 also operates to cause pivoting jaws 7 to engage and disengage pipe 2. When axial jaw 5 is fully in the rearward position, pivoting jaws 7 are fully open as seen in FIG. 1. As axial jaw 5 moves forward, inclined cam surfaces 18 will begin to engage roller surfaces 7b of pivoting jaws 7. As roller surfaces 7b are forced outward, pivoting jaw 7 begins to rotate around pivot points 13. This rotational movement then causes arcuate segments 7a of pivoting jaws 7 to begin to close on pipe 2 as seen in FIG. 2. As the pivoting jaws 7 completely close on pipe 2, locking surface 18a will engage roller surfaces 7b and hold pivoting jaws 7 firmly in place as seen in FIG. 3. It can be seen that the simultaneous closing of pivoting jaws 7 and axial jaw 5 will substantially enclose pipe 2.
To release pipe 2, axial jaw 5 is moved to a rearward position and locking surfaces 18a and cam surfaces 18 are removed from engagement with roller surfaces 7b. As best seen in FIG. 6 through the cutaway section of jaw 5, biasing device 19 will be connected to and between the two roller surfaces 7b in order to bias the roller surfaces 7b toward each other when cam surfaces 18 are not engaging roller surfaces 7b. While biasing device 19 is positioned beneath axial jaw 5 in the embodiment shown, any manner of connecting biasing device 19 to the cam surfaces 18 may be used as long as cam surfaces 18 are biased together and axial jaw 5 may engage pipe 2. In the embodiment shown, biasing device 19 is a spring 33.
An alternate embodiment of the present invention is shown in FIG. 5. In this embodiment, arcuate jaws 107a and 107b will have a locking mechanism 100 to securely lock jaws 107a and 107b together. The locking mechanism shown in the figures is locking hooks 101a and 10lb. Locking hooks 101a and 10lb are positioned so as to face in opposing directions from each other so as to lock when arcuate jaws 107a and 107b are brought together.
In order for locking hooks 101a and 10lb to matingly engage, locking hook 101a must pass center line C prior to locking hook 10lb reaching center line C. This is accomplished by having movable cam surface 118a engage roller surface 109a prior to cam surface 118b engaging roller surface 109b. As seen in FIG. 5, both cam surfaces 118a and 118b are connected to axial jaw 105 by bolts 120. However, the side of axial jaw 105 to which movable cam surface 118a is attached further has a counter bored recessed area 121 around bolt 120 and a biasing member, such as spring 122, positioned in recessed area 121 and around bolt 120.
In its relaxed position, spring 122 biases movable cam surface 118a in an outward direction toward roller surface 109a. As described earlier, when the power tongs are to be closed, axial jaw member 105 begins to move forward. Because movable cam surface 118a extends outward further that cam surface 118b, movable cam surface 118a engages roller surface 109a prior to cam surface 118b engaging roller surface 109b. Thus arcuate jaw 107a proceeds toward center line C slightly ahead of arcuate jaw 107b. As locking hook 101a passes center line C, it is in a position slightly lower than locking hook 101b, which allows locking hook 101b to overlap locking hook 101a.
Simultaneously with the overlapping movement of locking hooks 101a and 101b, axial jaw 105 is causing pipe 2 to move towards arcuate jaws 107. As pipe 2 presses against arcuate jaws 107, locking hooks 101 are urged to matingly engage each other. To properly engage locking hooks 101 in the final locking position, roller surfaces 109 must both be displaced outwardly an equal distance by cam surfaces 118. This is accomplished by spring 122 being compressed and allowing movable cam surface 118a to be pushed against axial jaw 105 when the arcuate jaws 107 are completely closed. Thus cam surfaces 118a and 118b are applying equal closing force to jaws 107a and 107b respectively. As with the previously described embodiment, the pipe 2 may be released by the rearward movement of axial jaw 105.
A third embodiment of the invention is seen in FIG. 7. In this embodiment, the cam surfaces 218a and 218b provide different degrees of inclination as represented by angles α and β. It will be understood that the height a of both cam surfaces is equal. However, the length b of cam surface 218a is less than the length d of cam surface 218b. It will be readily apparent that these dimensions dictate that angle α of cam surface 218a will be greater than angle β of cam surface 218b.
The result of this difference in angles α and β is that pivoting jaw 207a will move toward center line C more quickly than pivoting jaw 207b. However, because the height a of cam surface 218a is equal to the height a of cam surface 218b, neither pivoting jaw will cross center line C to any greater degree than tho other.
Those skilled in the art will recognize that because pivoting jaws 207 are moving in an arcuate path, the travel of locking hooks 201 has both a horizontal and vertical component. Since pivoting jaw 207a moves toward center fine C ahead of pivoting jaw 207b, locking hook 201a will be in a lower position than locking hook 201b as both pivoting jaws 207 approach center line C. This allows the farthermost tip of locking hook 201b to extend over and engage the farthermost tip of locking hook 201a as pivoting jaws 207 close on center line C. At this point, roller surfaces 209 have engaged locking surfaces 219 and there will be no further pivoting motion by pivoting jaws 207. However, the pressure of pipe 2 moving against pivoting jaws 207 will typically cause some further engagement of locking hooks 201 as materials undergo the normal strain caused by the large forces associated with gripping pipe 2.
Those skilled in the art will readily see the many advantages presented in these latter two embodiments. In the first embodiment, all forces tending to spread the arcuate jaws 7a had to be born by the roller surfaces 7b acting against cam surface 18. To the contrary, in the last two embodiments just described, locking hooks 101 and 201 bear the majority of the spreading forces acting on arcuate jaws 107 and 207 and thereby provide a considerably stronger tool.
A fourth embodiment can be seen in FIG. 8. This embodiment operates on a somewhat different principle than the previously discussed embodiments. In FIG. 8, the pivoting jaws 302 are closed by the operation of linear actuators such as hydraulic piston assemblies 306a and 306b. While the linear actuators shown are hydraulic piston assemblies, the linear actuators could be any other device, such as powers screws, that will impose a linear force on pivoting jaws 302.
Each of the pivoting jaws 302 will have an external surface 310 and a bracket 305 attached to external surface 310. The hydraulic rams 308 of hydraulic piston assemblies 306a and 306b will be pivotally attached to brackets 305. The hydraulic cylinders 307 of hydraulic piston assemblies 306a and 306b will be attached to the tong body 3.
In operation, the piston assemblies 306a and 306b will exert a linear force on pivoting jaws 302. Because the brackets 305 provide a pivotal connection, the linear force causes pivoting jaws 302 to rotate on pivot points 313 and to close the jaws as illustrated in the previous embodiments. Also as shown in the previous embodiments, it is necessary that locking hook 301a move into a closed position slightly ahead of locking hook 301b. This may be accomplished by causing piston assembly 306a to extend ram 308 at a faster rate than piston assembly 306b or by causing piston assembly 306a to begin extending ram 308 at an earlier point in time than piston assembly 306b begin to extend ram 308. Either of these methods may be accomplished by any conventional means for controlling the relative flow of hydraulic fluid into piston assemblies 306a and 306b.
While many parts of the present invention have been described in terms of specific embodiments, it is anticipated that still further alterations and modifications thereof will no doubt become apparent to those skilled in the art. It is therefore intended that the following claims be interpreted as covering all such alterations and modifications as fall within the true spirit and scope of the invention.
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The present invention provides back-up power tongs for holding a tubular member against rotation of a connected tubular member. The back-up power tongs comprise a body with a front section for receiving the tubular member and a plurality of jaw members for engaging the tubular member. The jaw members are positioned to form a substantially closed perimeter around the tubular member and at least one of the jaw members is a pivotal jaw, moving in a pivotal path to engage the tubular member. An alternate embodiment provides two pivoting jaws and a locking mechanism attached to the end of the pivoting jaws such that the pivoting jaws can be securely interlocked. The improved back-up tongs should not require that the tong body to virtually enclose the pipe and thus will allow the improved back-up tongs to be considerably smaller. The smaller size of the tongs will allow more versatile use since the tongs can operate in areas with less clearance than prior art tongs. The improved back-up tongs should also be less costly as they will require a considerably smaller amount of material to construct. Additionally, the improved back-up power tongs will be adaptable to many uses other than breaking pipe in conjunction with conventional power tongs. The present invention also may have application as a gripping device positioned on cranes or other lifting apparatus.
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BACKGROUND OF THE INVENTION
The present invention relates to an automatic accompaniment apparatus, such as an auto-rhythm machine, auto-bass machine, and the like and, more particularly, to an automatic accompaniment apparatus for receiving a plurality of arbitrary tones and generating musical tones in accordance with an accompaniment pattern.
In a known conventional auto-rhythm apparatus, a waveshape of a tone signal input therein through, e.g., a microphone, is stored in a RAM (Random Access Memory), and the input tone waveshape is read out from the RAM in accordance with a rhythm pattern, thereby generating a rhythm tone (e.g., Japanese Utility Model Laid-Open No. 60-145497).
With the conventional apparatus, however, a waveshape for only one tone can be stored in the RAM. Therefore, the rhythm performance becomes monotonous.
In order to provide various rhythm performance modes, a plurality of input tone waveshapes have to be stored. As a method to do it, it can be considered that a plurality of RAMs are arranged, or an address of a single RAM is divided to determine a plurality of memory areas which can be independently accessed, and that, thus, different input tone waveshapes are stored in each RAM or in each memory area.
However, with this arrangement, each RAM or memory area must have a capacity capable of storing a waveshape corresponding to a maximum data volume among input tone waveshapes. Therefore, the total memory capacity of a waveshape memory is increased, and for a waveshape having a small data volume, the corresponding memory space becomes nonusable.
SUMMARY OF THE INVENTION
It is, therefore, a principle object of the present invention to provide an automatic accompaniment apparatus which can realize various accompaniment tone modes.
It is another object of the present invention to provide an automatic accompaniment apparatus which can eliminate a nonusable memory space, and needs only a small memory capacity.
In order to achieve the above objects, there is provided an automatic accompaniment apparatus, comprising: accompaniment pattern generation means for generating a plurality of accompaniment patterns which represent timing of generation of a plurality of accompaniment tones to be generated respectively, the accompaniment patterns corresponding to the accompaniment tones; tone input means for inputting the accompaniment tones to be generated and for changing the accompaniment tones into a plurality of tone date respectively; first memory means; second memory means having a plurality of storage locations corresponding to the accompaniment patterns respectively; writing means for writing sequentially the tone data in the first memory means and for writing a plurality of area information identifying respectively storage areas of the first memory means in which the tone data are stored, into corresponding ones of the storage locations; and reading out means for reading out the area information from the storage locations corresponding to the accompaniment patterns and for reading out the tone data from the storage area identified by the area information read out whereby accompaniment tones can be produced in accordance with the tone data read out.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a circuit arrangement of an auto-rhythm apparatus according to an embodiment of the present invention;
FIG. 2 is a circuit diagram showing an arrangement of a lower address, data generator shown in FIG. 1;
FIG. 3 is a circuit diagram showing an arrangement of a start/end address data generator shown in FIG. 1;
FIG. 4 is a circuit diagram showing a modification of a memory selection controller; and
FIG. 5 is a block diagram showing a circuit arrangement of an electronic musical instrument comprising an automatic accompaniment apparatus according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an auto-rhythm apparatus according to an embodiment of the present invention. The auto-rhythm apparatus has a rhythm tone generator RTG having time-divisional 12 tone generation channels. More specifically, the rhythm tone generator RTG includes a first waveshape memory 10 comprising a RAM to which waveshape data for 12 tones can be written, and a second waveshape memory 12 comprising a ROM (Read-Only Memory) in which waveshape data for 12 tones have been factory-set in advance. The waveshape data is read out from either of the waveshape memories (10 or 12) in a time-divisional manner in accordance with a selected rhythm, thereby achieving an auto-rhythm performance.
Waveshape Data Write Access to First Waveshape Memory 10 (FIG. 1)
In the circuit shown in FIG. 1, when waveshape data is written in the first waveshape memory 10, a write/read control switch 14 is turned on. Then, a write/read control signal W/R goes to logic level "1", and the first waveshape memory 10 and a lower address data generator 16 are set in a write mode. In this case, since a gate circuit 18 is enabled, a channel number is displayed on a channel display 20 in accordance with channel number data CH. In addition, since a gate circuit 22 is enabled, a lower address is displayed on an address display 24 in accordance with write lower address data WAD.
Upon write access of waveshape data, a RAM/ROM switch 26 is set in an ON state in advance. A memory selection signal RA/RO goes to logic level "1", and a start address memory 28B comprising a RAM in a start/end address data generator 28 is enabled.
An input terminal 30 is connected to a microphone 32 or an external machine 34 such as a tape recorder, so as to input an arbitrary tone signal (e.g., a percussive tone signal, a human or animal voice signal, and the like). Assuming that a desired tone signal is input, the input tone signal is supplied to a loudspeaker 38 through an input amplifier 36 and a resistor R 1 to generate a corresponding tone, and is also supplied to a level detector 40 through the input amplifier 36.
The level detector 40 sets an R-S flip-flop 42 substantially in synchronism with the leading edge of the input signal. For this reason, an output Q from the flip-flop 42 goes to logic level "1". In response to this, a write instruction pulse WI S for a start address is sent out from a rise differentiator 44, and is supplied to the start/end address data generator 28.
In the start/end address data generator 28, when the write/read control signal W/R goes to logic level "1", a channel counter 28A consisting of a duodecimal counter is reset. The channel counter generates channel number data CH representing a channel number "0", and the channel display 20 displays the channel number "0" accordingly. In the generator 28, start address data indicating a start address "0" of a first tone is stored in a memory area corresponding to the channel number "0" of the start address memory 28B in accordance with the write instruction pulse WI S . The start address data is read out immediately after it is written, and is supplied to an adder 46 as upper address data UAD.
When the output Q from the flip-flop 42 goes to logic level "1", the output from an OR gate 48 goes to logic level "1", and the "1" output is supplied to an AND gate 50. The AND gate 50 also receives the write instruction pulse WI S through an inverter 52. For this reason, the output from the AND gate 50 goes to logic level "1" to be delayed by an interval corresponding to the pulse width of the write instruction pulse WI S after the output Q from the flip-flop 42 goes to logic level "1". The "1" output from the AND gate 50 is supplied to the lower address data generator 16 as a write enable signal WEN.
The lower address data generator 16 has a write address counter 16A. The counter 16A counts a clock signal φ when the write enable signal WEN goes to logic level "1", so as to generate write lower address data WAD, and the address display 24 displays the lower address accordingly. The lower address data WAD is supplied to the adder 46, and is added to the upper address data UAD. The sum output from the adder 46 is supplied to the first waveshape memory 10 as address data AD.
An A/D (analog-to-digital) converter 54 A/D converts an input tone signal from the input amplifier 36 for each sample point, and supplies digital waveshape data TWD representing an amplitude to the first waveshape memory 10 for each sample point.
In the first waveshape memory 10, a memory area M 1 corresponding to the channel number "0" is designated in accordance with the address data AD, and the waveshape data TWD for the first tone is written in the area M 1 . In this case, a start address S 1 of the memory area M 1 is "0", as described above, and an end address E 1 is determined as follows.
More specifically, when the level detector 40 resets the flip-flop 42 substantially in synchronism with completion of decay of the first tone, the output Q from the flip-flop 42 goes to logic level "0", and an output Q goes to logic level "1". A delay circuit 56 is adopted to delay the output Q from the flip-flop 42 by several periods of the clock signal φ. When the output Q from the flip-flop 42 goes to logic level "0", the output from the delay circuit 56 goes to logic level "0" to be delayed therefrom by the several periods, and the write enable signal WEN also goes to "0" in response to this. For this reason, in the lower address data generator 16, the write address counter 16A stops counting of the clock signal φ, and the count value at this time is used as the end address E 1 . In this manner, when the end address is determined to be slightly delayed from the completion of decay of the first tone, the memory area M 1 for the first tone can have a certain margin. Note that the end address E 1 can be confirmed using the address display 24.
The rise differentiator 58 synchronously generates a write instruction pulse WI E when the output from the delay circuit 56 goes from logic level "1" to "0", and supplies it to the start/end address data generator 28. In the generator 28, end address data indicating the end address E 1 is written in a memory area corresponding to the channel number "0" of an end address memory 28C comprising a RAM. The written end address data is used for stop-controlling waveshape data read access from the first waveshape memory 10.
After waveshape data write access for the first tone is completed as described above, a counter reset switch 60 is turned on. In response to this, a counter reset signal ACR goes to logic level "1", and the write address counter 16A in the lower address data generator 16 is reset to a count value "0". The output from an AND gate 62, which receives the output Q="1", goes to logic level "1" in accordance with the counter reset signal ACR="1", and a light-emitting diode 64 is turned on accordingly. The ON state of the light-emitting diode 64 indicates that waveshape data write access for a second tone is allowed.
Thereafter, when a step switch 66 is turned on once to generate a step signal SS, the count value of the channel counter 28A in the generator 28 is incremented by one. More specifically, channel number data CH representing a channel number "1" is generated from the channel counter, and the channel display 20 displays the channel number "1" accordingly.
Assuming that a second tone signal is input through the input terminal 30, the write instruction pulse WI S is generated in the same manner as described above, and in the generator 28, the start address data for the second tone is written in a memory area corresponding to the channel number "1" of the start address memory 28B. The start address data for the second tone represents a start address S 2 obtained by adding 1 to the end address E 1 of the first tone. The start address data for the second tone is supplied to the adder 46 as the upper address data UAD.
The AND gate 50 generates the write enable signal WEN in the same manner as described above, and the write address counter in the generator 16 supplies the write lower address data WAD to the adder 46 in response to this. Therefore, waveshape data TWD for the second tone is written in a memory area M 2 corresponding to the channel number "1" of the first waveshape memory 10 in accordance with the address data AD from the adder 46 in the same manner as described above.
When the output from the AND gate 50 goes from logic level "1" to "0" to be slightly delayed from the completion of decay of the second input tone, the write address counter 16A in the generator 16 stops counting in the same manner as described above, and the count value at the time is used as an end address E 2 for the second tone. The rise differentiator 58 generates the write instruction pulse WI E , and in the generator 28, end address data indicating the end address E 2 is written in a memory area corresponding to the channel number "1" of the end address memory 28C accordingly.
Thereafter, the above-mentioned processing is repeated such that after the counter reset switch 60 is turned on, the channel number is incremented by one by the step switch 66, and a desired tone signal is input. In this manner, waveshape data for a maximum of 12 tones can be written in the first waveshape memory 10, and 12 rhythm tone generators can be assigned to 12 tone generation channels. With this sequential write method, the number of addresses of the memory areas M 1 to M 12 is determined in accordance with a waveshape data volume of the corresponding input tone, and cannot become constant as long as different tones are input.
When waveshape data written in the first waveshape memory 10 is to be erased, an erase switch 65 is turned on. In response to this, an erase instruction signal ER as an output from an inverter 67 connected to the erase switch 65 goes to logic level "0", and the waveshape data in the first waveshape memory 10 is erased. In addition, the address data in the start address memory 28B and the end address memory 28C are erased.
Auto-Rhythm Performance Based on Storage Data (FIG. 1)
Upon auto-rhythm performance, storage data in either of the first or second waveshape memory 10 or 12 is used.
A case will be described wherein storage data in the first waveshape memory 10 is used. In this case, when the write/read control switch 14 is turned off, the write/read control signal W/R goes to logic level "0", and the first waveshape memory 10 and the lower address data generator 16 are set in a read mode. Since the gate circuits 18 and 22 are disabled, the channel display 20 and the address display 24 do not perform a display operation.
In the start/end address data generator 28, when the write/read control signal W/R goes to logic level "0", the channel counter 28A counts the clock signal φ, and generates the channel number data CH. Since the channel counter 28A comprises the duodecimal counter, data representing channel numbers "0" to "11" are sequentially and repetitively sent as the channel number data CH.
When the first waveshape memory 10 is used, since the RAM/ROM switch 26 is turned on in advance, the start address memory 28B and the end address memory 28C each comprising the RAMs in the generator 28 can be used. Start address data for 12 channels (12 tones) are sequentially read out from the start address memory 28B in accordance with the channel number data, and are supplied to the adder 46 as the upper address data UAD. End address data for 12 channels are sequentially read out from the end address memory 28C in accordance with the channel number data CH, and each end address data EAD is supplied to a comparator 68 as a comparison input B.
A rhythm pattern pulse generator 70 includes a rhythm pattern memory in which a large number of rhythm patterns corresponding to a large number of types of rhythm, such as "march", "waltz", "swing", and the like, are factory-set. A rhythm pattern read out from the rhythm pattern memory can be designated by rhythm selection data SEL from a rhythm selector 72.
A rhythm pattern corresponding to each type of rhythm consists of pattern data for one measure corresponding to count values "0" to "95" of tempo clock pulses. The pattern data corresponding to each count value represents a channel to be subjected to tone generation of the 12 tone generation channels at a tone generation timing corresponding to the count value.
When a rhythm start/stop switch 74 is turned on, a start/stop control signal ST/SP goes to logic level "1", and the rhythm pattern generator 70 sends out rhythm pattern pulses RP in a time-divisional manner in accordance with a rhythm pattern corresponding to the selected type of rhythm. More specifically, each rhythm pattern pulse is supplied to the lower address data generator 16 in a time slot corresponding to a channel to be subjected to tone generation of 12 time slots in accordance with the channel number data CH, and is used as a tone generation instruction signal for each channel.
The lower address data generator 16 has a read address counter 16B which can count the clock signal φ in a time-divisional manner. The counter 16B counts the clock signal φ at the timing corresponding to a channel to be subjected to tone generation according to the rhythm pattern pulse, and supplies its count output to the adder 46 as lower address data RAD. The lower address data RAD is also supplied to the comparator 68 as a comparison input A.
The adder 46 adds the start address data as the upper address data UAD and the read lower address data RAD, and supplies the sum output to the first waveshape memory 10 as the address data AD. As a result, waveshape data can be time-divisionally read out from the first waveshape memory 10 in accordance with the address data AD. For example, when the rhythm pattern RP is generated so as to instruct tone generation at channels of the channels numbers "0" and "2" in association with a given tone generation timing, waveshape data stored in the memory areas M 1 and M 3 are time-divisionally read out from the first waveshape memory 10. When the read access of the waveshape data is completed for each memory area, the comparator 68 generates an equal signal EQ upon detecting coincidence between the comparison inputs A and B. In response to this, a count value corresponding to the channel of the read address counter 16B associated with the coincidence is reset to "0".
A selector 76 can select the input A since the memory selection signal RA/RO is at logic level "1". For this reason, the waveshape data read out from the first waveshape memory 10 is supplied to an accumulator 78 through the selector 76.
The accumulator 78 accumulates readout data for a plurality of channels based on the channel number data CH and outputs waveshape data representing a composite waveform. The output data from the accumulator 78 is converted to an analog signal by a D/A (digital-to-analog) converter 80. The analog signal from the D/A converter 80 is supplied to the loudspeaker 38 through an output amplifier 82 and a resistor R 2 , and is converted to an acoustic sound.
As described above, when waveshape data is time-divisionally read out from the first waveshape memory 10 in accordance with the selected rhythm pattern, an auto-rhythm performance can be performed. In this case, when the waveshape data stored in the first waveshape memory 10 is rewritten, an arbitrary rhythm tone generator group can be set. Therefore, various rhythm performance modes can be enjoyed.
When the auto-rhythm performance is to be stopped, the rhythm start/stop switch 74 can be turned off.
A case will be described wherein storage data in the second waveshape memory 12 is used. In this case, the write/read control switch 74 is turned off in the same manner as described above. In addition, the RAM/ROM switch 26 is also turned off. In response to this, the memory selection signal RA/RO goes to logic level "0", and a start address memory 28D and an end address memory 28E in the generator 28 are enabled. In response to the memory selection signal RA/RO="0", the selector 76 is allowed to select the input B as the readout data from the second waveshape memory 12.
Thereafter, when the rhythm start/stop switch 74 is turned on, the auto-rhythm performance can be made by the same time-divisional readout operation as described above, except that the memories 12, 28D, and 28E are used instead of the memories 10, 28B and 28C.
Lower Address Data Generator (FIG. 2)
FIG. 2 shows the arrangement of the lower address data generator 16.
In the write mode, an AND gate 90 is enabled in response to the write enable signal WEN="1", and supplies the clock signal φ to the write address counter 16A. The counter 16A counts the clock signal φ, and supplies the write lower address data WAD as its count output to the selector 92 as the input A. The counter 16A also supplies the data WAD to the start/end address data generator 28 and the gate circuit 22, as shown in FIG. 1.
The selector 92 selects the input A in the write mode in which the write/read control signal W/R is at logic level "1". For this reason, the write lower address data WAD from the counter 16A is supplied to the adder 46 shown in FIG. 1 through the selector 92.
When the write enable signal WEN goes to logic level "0" after decay of the input tone is ended, the AND gate 90 is disabled and the counter 16A stops counting.
The counter 16A is reset in response to the counter reset signal ACR.
In the read mode, a time-divisional latch circuit 94 and the read address counter 16B can be used. The rhythm pattern RP is input to a 12-stage/1-bit shift register (S/R) 96 which is operated in response to the clock signal φ. The rhythm pattern pulse RP output from the shift register 96 is input to a 12-stage/1-bit shift register (S/R) 100 through an OR gate 98, and is shifted in accordance with the clock signal φ. The rhythm pattern pulse sent out from the shift register 100 is input again to the shift register 100 through an AND gate 102 and the OR gate 98, and thereafter, is cyclically stored in this closed loop.
The rhythm pattern pulse sent out from the shift register 100 is also supplied to a gate circuit 104. The gate circuit 104 is arranged along a data path extending from an adder 106 to a 12-stage/m-bit (m corresponds to the number of bits of the counter 16A) shift register (S/R) 108. The adder 106 adds "1" to the least significant bit of the output data from the shift register 108 and outputs it. The shift register 108 performs a shift operation in response to the clock signal φ. Therefore, the gate circuit 104, the adder 106, and the shift register 108 constitute a time-divisional counter which is operated synchronously with the shift registers 96 and 100.
For example, when the shift register 100 sends out the rhythm pattern pulse at every timing of a 0th channel, the time-divisional counter is incremented by one at every timing corresponding to the 0th channel. This also applies to timings for first to 11th channels. In the counter 16B, the time-divisional count operation for 12 channels can be performed in this manner.
The count output from the counter 16B is sent out as the read lower address data RAD, and is input to the selector 92 as the input B. The selector 92 is allowed to select the input B in the read mode in response to the write/read control signal W/R="0". Therefore, the read lower address RAD is supplied to the adder 46 and the comparator 68 shown in FIG. 1 through the selector 92.
When the equal signal EQ is output from the comparator 68 upon completion of read access of waveshape data for one tone, the equal signal is supplied to an inverter 112 through an OR gate 110. The AND gate 102 is disabled since the output from the inverter 112 is at logic level "0", and the rhythm pattern pulse which is cyclically stored is erased. Therefore, the gate circuit 104 is disabled at a timing of a channel associated with a detected coincidence, and the count value corresponding to the channel is reset to "0".
If the rhythm pattern pulse RP of the same channel as that of the rhythm pattern pulse which is cyclically stored arrives before the equal signal EQ is generated, the rhythm pattern pulse disables the AND gate 102 through the OR gate 110 and the inverter 112. Therefore, the count value of the counter 16B is reset in the same manner as in the case of the equal signal EQ. The rhythm pattern pulse at this time is input to the shift register 100 through the shift register 96 and the OR gate 98, and is cyclically stored in the same manner as described above. The counter 16B starts counting for the reset channel. As a result, during read access of waveshape data for one tone, when a rhythm pattern pulse is generated for the same tone, the waveshape data can be read out from the start address.
Start/End Address Data Generator (FIG. 3)
FIG. 3 shows the arrangement of the start/end address generator 28.
In the write mode, a selector 110 selects the step signal SS from the step switch 66 shown in FIG. 1 in response to the write/read control signal W/R="1" and to supply it to the channel counter 28B.
When the write/read control signal W/R goes to logic level "1", the channel counter 28B is reset in accordance with the output from a rise differentiator 112 which receives the signal W/R. The channel number data CH representing the count value (channel number) "0" at this time is supplied to the gate circuit 18 shown in FIG. 1, and is also supplied to a comparator 114 as an input A. Data representing a numerical value "1" is input to a data source 116 as an input B of the comparator 114.
The comparator 114 compares the inputs A and B. and generates an output "1" if A≧B. When the count value of the counter 28A is "0" as described above, the comparator 114 generates an output "0". For this reason, a selector 118 selects data indicating numerical value "0" (data of all "0" bits) from a data source 120, and supplies the selected data to the start address memory 28B. At this time, in the memory 28B, the memory area corresponding to the channel number "0" is selected in accordance with the channel number data CH.
When the write instruction pulse WI S is generated in response to the first input tone, start address data indicating "0" is written in a memory area corresponding to the channel number "0" of the memory 28 in accordance with this pulse. The start address data is read out from the memory 28B when the write instruction pulse WI S is disabled, and is supplied to a selector 122 as an input A.
In the write mode, the selector 122 selects the input A in accordance with the memory selection signal RA/RO="1". Therefore, the start address data read out from the memory 28B is supplied to the adder 46 shown in FIG. 1 as the upper address data UAD through the selector 122.
When decay of the first input tone is ended and the counter 16A shown in FIG. 2 stops counting, the write lower address data WAD indicating the count value at this time is supplied to the end address memory 28C. At this time, in the memory 28C, a memory area corresponding to the channel number "0" is selected in accordance with the channel number data CH. When the write instruction pulse WI E is generated in synchronism with the count stop of the counter 16A, the lower address data WAD representing the count value when the counter 16A is stopped is written as end address data in a memory area corresponding to the channel number "0" of the memory 28C in accordance with this pulse. The same lower address data WAD (end address data) as that written in the memory 28C is latched by a latch 124 in accordance with the write instruction pulse WI E .
Thereafter, when the step signal SS is generated, the count value of the counter 28A becomes "1", and a memory area corresponding to the channel number "1" is selected in each of the memories 28B and 28C accordingly. When the count value of the counter 28A becomes "1", the output from the comparator 114 also becomes "1", and the selector 118 thus selects the output from an adder 126, and supplies the selected output to the memory 28B.
The adder 126 adds the end address data from the latch 124 and the numerical value "1" from a data source 128, and a start address value that is larger than the end address value by one can be calculated by this addition.
When the write instruction pulse WI S is generated in response to the second input tone, the output data from the adder 126 is written as start address data in a memory area corresponding to the channel number "1" of the memory 28B in accordance with this pulse.
Thereafter, address data for a maximum of 12 channels can be written in the memories 28B and 28C with the same operation as above.
Note that the address data written in the memories 28B and 28C can be erased when the erase switch 65 is turned on so as to set the erase instruction signal ER at logic level "0".
The read mode will be described hereinafter.
In this case, the selector 110 selects the clock signal φ in accordance with the write/read control signal W/R="0", and supplies the selected signal to the counter 28A. The counter 28A counts the clock signal φ, whereby its count value changes like 0, 1, 2, . . . , 11, 0, 1, . . . . Data are read out from the memories 28B, 28C, 28D, and 28E in accordance with the channel number data CH corresponding to the count values.
The start address data read out from the start address memories 28B and 28D are supplied to the selector 122 as the inputs A and B, respectively, and the end address data read out from the end address memories 28C and 28E are supplied to a selector 130 as inputs A and B.
The selection operations of the selectors 122 and 130 are controlled in accordance with the memory selection signal RA/RO. When the first waveshape memory 10 is used, both the selectors 122 and 130 select their inputs A in accordance with RA/RO="1". As the upper address data UAD, the readout data from the memory 28B is supplied, and as the end address data EAD, the readout data from the memory 28C is delivered. When the second waveshape memory 12 is used, both the selectors 122 and 130 select their inputs B in accordance with the RA/RO="0". For this reason, as the upper address data UAD, the readout data from the memory 28D is delivered, and as the end address data EAD, the readout data from the memory 28E is delivered.
Modification of Memory Selection Controller (FIG. 4)
FIG. 4 shows the modified version of the memory selection controller. A memory selection signal RA'/RO' output from the controller is used instead of the memory selection signal RA/RO in the circuit shown in FIG. 1.
When the write/read control signal W/R goes to logic level "1" (the write mode is set), a rise differentiator 132 generates an output pulse to reset a 12-stage/1-bit shift register (S/R) 134, and a selector 136 selects one of its inputs. In this state, when a RAM designating switch 138 is turned on, a signal "1" is input to the shift register 134 through an OR gate 140. As a result, waveshape data stored in the memory area M 1 of the first wave shape memory (RAM) 10 can be used as a rhythm tone generator for the 0th channel. If the switch 138 is not turned on, waveshape data in a memory area corresponding to the channel number "0" of the second waveshape memory (ROM) 12 can be used as a rhythm tone generator for the 0th channel.
When the step switch 66 shown in FIG. 1 is turned on once to generate the step signal SS, the signal SS is supplied to the shift register 134 as a shift pulse SFP through the selector 136, and the shift register 134 performs a shift operation for one stage in response to this. In this state, a rhythm tone generator for the first channel can be selected (i.e., RAM or ROM can be selected in accordance with "1" or "0") in the same manner as described above.
Memory selection of "1" (RAM) or "0" (ROM) is allowed for each channel of the channel numbers "0" to "11". For example, "1" can be selected for the 0th to third channels, and "0" can be selected for the fourth to 11th channels. In this case, since waveshape data stored in the second waveshape memory 12 is used as the rhythm tone generator for the fourth to 11th channels, write access of waveshape data for the fourth tone and thereafter into the first waveshape memory 10 can be omitted. Thus, an input operation can be facilitated as compared to a case wherein waveshape data for 12 tones are written.
In the read mode, the selector 136 selects the clock pulse φ in accordance with the write/read control signal W/R="0", and supplies the selected signal to the shift register 134 as the shift pulse SFP. For this reason, signals "1" or "0" for 12 channels are sequentially read out from the shift register 134, and are input again back to the shift register 134 through the OR gate 140. As a result, the memory selection signal RA'/RO' of a time-divisional multiple format, which represents "1" or "0" for each channel, is repetitively output from the shift register 134.
In the read mode, when the memory selection signal RA'/RO' is used instead of the memory selection signal RA/RO in the circuit shown in FIG. 1, the RAM group including the memories 28B, 28C, and 10 and the RAM group including the memories 28D, 28E, and 12 can be time-divisionally switched. Therefore, the auto-rhythm performance using both the rhythm tone generators of the first and second waveshape memories 10 and 12 can be achieved. When the storage contents of the shift register 134 and the memory 10 are appropriately changed, various rhythm performance modes can be enjoyed.
Another Embodiment (FIG. 5)
FIG. 5 shows the circuit arrangement of an electronic musical instrument comprising an automatic accompaniment apparatus according to another embodiment of the present invention. The same reference numerals in FIG. 5 denote the same parts as in FIG. 1. The characteristic feature of this embodiment is that the present invention is applied to auto-bass tone generation.
A keyboard circuit 150 includes one or a plurality of stages of keyboards each having a first key area for a melody performance and a second key area for an accompaniment performance. A key-depression detector 152 detects key-operation data from the keyboard circuit 150.
The key-operation data detected from the first and second key areas are supplied to a musical tone forming circuit 156. The musical tone forming circuit 156 forms musical tone signals such as a melody tone signal, a chord tone signal, and the like based on the input key-operation data, and supplies the signals to a loudspeaker 38 through a resistor R 3 . Therefore, musical tones corresponding to keys depressed in the first and/or second key areas are generated from the loudspeaker 38.
The key-operation data detected from the second key area is supplied to a bass pattern pulse generator 158. The generator 158 also receives rhythm selection data SEL from a rhythm selector 72.
The bass pattern pulse generator 158 includes a chord name detector, a bass pattern memory, a pitch determination circuit, and the like.
The chord name detector detects a chord name (root and chord type) based on the supplied key-operation data. The base pattern memory stores bass patterns corresponding to chord types, such as major, minor, seventh, and the like for each rhythm pattern. Each bass pattern includes interval data representing an interval with respect to the root of a bass tone to be generated at each tone generation timing. Interval data of a bass pattern corresponding to the selected rhythm type and the detected chord type is read out from the bass pattern memory. The pitch determination circuit determines a pitch of a bass tone to be generated based on the detected root and the readout interval data, and assigns a bass pattern pulse BP in a time slot corresponding to the determined pitch and outputs it.
A bass tone generator BTG has the same arrangement as that of the rhythm tone generator RTG as described above, and can receive 12 arbitrary tones. An input tone signal is supplied to the loudspeaker 38 through a resistor R 4 and is converted to an acoustic sound.
The bass pattern pulse BP is supplied to a lower address data generator 16' having the same arrangement as that of the lower address generator 16 described above instead of the rhythm pattern pulse RP. Waveshape data for 12 tones can be sequentially written in a first waveshape memory (corresponding to the memory 10 in FIG. 1) comprising a RAM in the bass tone generator BTG. For example, waveshape data corresponding to bass tones of G 2 , G.sup.♯ 2 , A 2 , A.sup.♯ 2 , and B 2 , bass guitar tones of C 3 , C.sup.♯ 3 , D 3 , D.sup.♯ 3 , and E 3 , and guitar tones of F 3 and F.sup.♯ 3 can be sequentially written in the first waveshape memory. In this case, if the bass pattern pulse BP is assigned to a time slot corresponding to the 11th channel, a guitar tone signal of F.sup.♯ 3 is sent out from the bass tone generator BTG. The guitar tone signal is supplied to the loudspeaker 38 through a resistor R.sub. 5, and is converted to an acoustic sound.
According to the embodiment shown in FIG. 5, the bass tone generator group used for an auto-bass performance can be desirably set, and various bass performance modes can be enjoyed.
In the above embodiment, factory-set patterns are used as accompaniment patterns such as rhythm patterns, bass patterns, and the like. However, the accompaniment patterns can be set (programmed) by a user.
The present invention can also be applied to auto-arpeggio generation and the like.
According to the present invention as described above, a plurality of arbitrary tones are input, corresponding waveshape data are written in a waveshape memory such as a RAM, and waveshape data for a plurality of tones are selectively read out from the waveshape memory in accordance with an accompaniment pattern. Therefore, various automatic performance modes can be enjoyed by changing input tones or changing an accompaniment pattern.
Since waveshape data for a plurality of tones are written in the waveshape memory, the memory space of the waveshape memory can be effectively used, and the memory capacity can be decreased.
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An automatic accompaniment apparatus includes an accompaniment pattern generation unit for generating a plurality of accompaniment patterns which represent timing of generation of a plurality of accompaniment tones to be generated respectively. The accompaniment patterns correspond to accompaniment tones. The apparatus also includes a tone input unit for inputting the accompaniment tones to be generated and for changing the accompaniment tones into a plurality of tone date respectively, a first memory, second memory having a plurality of storage locations corresponding to the accompaniment patterns respectively, a writing unit for writing sequentially the tone data in the first memory and for writing a plurality of area information identifying respectively storage areas of the first memory in which the tone data are stored, into corresponding ones of the storage locations, and a reading out unit for reading out the area information from the storage locations corresponding to the accompaniment patterns and for reading out the tone data from the storage area identified by the area information read out. The accompaniment tones can be produced in accordance with the tone data read out.
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FIELD OF THE INVENTION
The invention is concerned with local bone regeneration for long bones. More specifically, the invention relates to the use of locally-applied vacuum to stimulate osteoblastic activity in long bones with discontinuity defects.
BACKGROUND OF THE INVENTION
Osteogenesis, the growth of new bone, is a part of the normal healing process, and involves recruiting and activating osteoblast cells in bone. This can be a slow process, particularly in the elderly and after severe trauma to the bone and after disease. The ability to accelerate osteogenesis would speed the healing process after trauma and after orthopedic and dental procedures. Methods to accelerate the process, particularly in local areas of bone, have been a holy grail for scientists for many years.
Current techniques of bone regeneration include: traditional methods such as distraction osteogenesis in which bone is pulled in an appropriate direction to stimulate growth, and bone grafting; and, experimental techniques that include use of drugs such as OP-1 that stimulate osteoblasts, implanting biomaterials laced with molecular signals designed to trigger the body's own repair mechanism, injecting bone marrow stem cells into the affected areas, and, transfusing cells that carry genes that code for bone-repair proteins. None of these methods are yet totally satisfactory, for a host of reasons. For a review of this subject see: Service, Science, 289:1498 (2000)
Distraction osteogenesis requires a bulky device and requires a very long period before positive results are seen. Bone grafting is limited by the quantity and quality of the patient's bone available for grafting. Biocompatible polymeric matrices without or with natural or recombinant bone morphogenic proteins suffer from a need for very large and very expensive quantities of these signal proteins. The gene therapy procedure suffers from the general problems of gene therapy in general. The use of the stem cell approach is greatly limited by the scarcity and expense of such cells; for example, in 50-year olds, there is only one stem cell in 400,000 bone marrow cells (see Service, 2000, above.
Applicant has previously described a device that applies subatmospheric pressures to a fractured or lesioned area of a flat bone (e.g., scapula), and thereby promotes osteogenesis and consequent bone healing in such areas (Lytinas, U.S. Pat. No. 6,491,683, which is incorporated herein by reference). However, for anatomical reasons such a device is not suitable for non-flat long bones of the upper and lower extremities, particulary where blunt trauma from accidents and/or projectiles produces in the long bone discontinuous defects leaving gaps of 2.5 cm and more. In the past such discontinuous defects have been treated orthopedically by grafting into the discontinuity pieces of bone taken from elsewhere in the body. More often than not, such grafting does not completely fill the discontinuity, thereby leading to poor healing (fibrous displacement) and shortened extremities.
Clearly, there is an acute need for a safe, simple, rapid, inexpensive and efficient device and method for producing osteogenesis in discontinuous regions of long bones. Such a device and method, based in principle on the vacuum technique discovered by the applicant (U.S. Pat. No. 6,491,693) has now been discovered, and is described below.
SUMMARY OF THE INVENTION
A device and method for producing bone regeneration (osteogenesis) in a discontinuous local section of a long bone in a subject requiring same, comprising the step of applying to the local section of the bone a vacuum (subatmospheric pressure) for an effective period of time.
In one embodiment, the discontinuous section of the long bone is sealed from the atmosphere with a flexible, sterilizable sleeve or cuff device of a dimension and curvature suitable to enclose and fit sealably tightly over the discontinuous or fractured section of the long bone, the device being connected through a sealable exit port to a source of vacuum, such that the discontinuous section of the long bone can be evacuated for an appropriate length of time.
DESCRIPTION OF THE FIGURES
FIG. 1 is a sketch of the sleeve/cuff device of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The essence of the invention is the production of bone regeneration (osteoblastic cell-induced osteogenesis) in a desired section of a long bone by the application to this section a vacuum (within the context of this specification the term vacuum is to be considered synonymous with subatmospheric pressure) for an effective length of time.
The method can be applied to any long bone in humans or animals. It can be applied to a wide variety of medical conditions, e.g., a bone that has been shattered by such trauma that produces a discontinuous section that requires osteogenesis; a bone that requires lengthening; a bone that needs reshaping, as after an accident; a bone after surgical removal of a cancerous or cystic section of the bone; and, in bone resorption areas (alveolar region).
The device of the invention is suitable for a variety of long bones, including a femur, a clavicle, ribs, humerus, ulna and radius, carpal and metacarpal bones and their phalanges, tibia, fibula, and, tarsal and metatarsal bones and their phalanges, among others.
At the heart of the invention is a device that produces the vacuum on the discontinuous or fractured section of the long bone. A highly preferred device is an evacuatable sleeve or cuff (the two terms are used interchangeably) that can be fitted around the discontinuous section or fracture of the bone and that can be maintained under vacuum through a port. The evacuation port is continuous with both the interior of the sleeve or cuff and the skin surrounding the bone being treated so that repeated re-evacuations may be easily applied by medical personnel.
In FIG. 1 , 1 is a representative example of a long bone being treated; 2 is a representative discontinuity defect; 3 is the sleeve or cuff that encloses the bone both above and below the discontinuity; 4 is the vacuum port that extends from the interior of the sleeve or cuff to outside the skin; 5 is the sealable port orifice that is connected to a vacuum pump or the like; 6 depicts sealant that is placed between the sleeve or cuff and the bone, above and below the discontinuity; and, 7 is the skin.
The sleeve or cuff should be composed of a flexible, sterilizable (e.g., autoclavable) material. It may be made of a light biocompatible metal or plastic, and its walls should be sufficiently thick so as not to collapse under vacuum. Snugness of the sleeve or cuff device is accomplished, in part, by fabricating the device so that the curvature of the portion resting against the bone is designed to fit the particular bone being treated, and, in part, by the flexibility of the sleeve or cuff. Sleeves or cuffs with a wide variety of sizes and shapes may be fabricated by well-known methods and kept on hand under sterile conditions.
The sleeve or cuff of the inventive device is hermetically glued to the bone above and below the discontinuity section with any appropriate surgical glue, e.g., an elastic silicone Nexaband Liquid, VPL, Inc. without or with glues of the type of KRAZY GLUE. It is important that the glue have elastic properties so that the vacuum seal will not be broken if the bone moves in place.
The sleeve or cuff, once attached to the bone, is evacuated by a vacuum pump (e.g., Nalgene vacuum pump, although any other vacuum pump is suitable) by means of the port ( 4 and 5 in FIG. 1 ). Following attainment of the desired degree of vacuum, the connection between the device and the pump is sealed. As the port extends through the skin, it is readily accessible for repeated evacuations of the system. The degree of vacuum is determined by the extent of the discontinuityl. For example, as little as 30 in. Hg is sufficient to induce bone regeneration in a skeletal bone. The vacuum port may also be fitted with an attached vacuum measuring gauge.
The device is maintained in place for an appropriate length of time before being removed. Determination of this appropriate length of time is based on the clinical condition being treated and the degree of regeneration required. This determination does not require undue experimentation by the medical or dental surgeon applying the technique.
The progress of bone regeneration may be followed radiographically, as a plastic version of the inventive device is radiolucent and new bone is not. The osteoid precursor stage of bone regeneration may not, however, always be visible by X-ray. At an appropriate time, the inventive device may be removed surgically, preferably by cutting it away from the bone by, for example, a dental burr.
The following example merely provides an embodiment of the inventive method, and should not be construed as limiting the claims in any way.
EXAMPLE 1
The Surgical Protocol
Under sterile conditions, the bone to be treated is reached surgically. Skin, fat, muscles, etc. are blunt-resected from the bone.
The autoclaved sleeve or cuff device is slipped around the desired discontinuity section of the bone, and sealed to the bone with surgical glue (e.g., Nexaband liquid, Veterinary Products Laboratories, Inc.).
The vacuum port of the device is attached to a vacuum pump, and the device evacuated to the desired pressure, e.g., about 30 in. Hg. At this point the vacuum port is sealed so as to maintain the vacuum. The subcutaneous tissues are closed with sutures, e.g., a 4-0 Dexonsuture, and the skin sutured closed.
The degree of vacuum can be monitored by a vacuum gauge attached to the vacuum port.
At an appropriate length of time, e.g., about four weeks, the device (still well-sealed) is removed from the long bone. An osseoid thickening of the bone at the site of the treatment will be noted.
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A method of stimulating bone regeneration in a discontinuous section of a long bone in a subject requiring same, comprising the step of applying to said discontinuous section of the bone an effective vacuum for an effective length of time. A device for carrying out the method consisting of a sealable tubular-shaped sleeve or cuff that fits snugly and sealably around the bone section to be treated and that can be evacuated via a port that is integral to the sleeve or port.
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BACKGROUND
1. Technical Field
The present invention relates to an electro-optical device such as, for example, a liquid crystal device, and to an electronic apparatus such as, for example, a liquid crystal projector, which incorporates the electro-optical device.
2. Related Art
According to JP-A-10-253990, in an electro-optical device, an electro-optical material is disposed between a pair of substrates, and image signals rather than data signals are supplied to pixel electrodes formed for each pixel of a pixel array region or an image display region on one substrate. An image is displayed by applying a voltage that is defined by a potential between a counter electrode and each of the pixel electrodes formed on the other substrate.
Here, in a peripheral region of the image display region on the one substrate, a sampling circuit for supplying an image signal via an image signal line to a data line by sampling, a data driving circuit for subsequently outputting an output of a shift register as a driving signal to the sampling circuit, and a scanning line driving circuit for subsequently supplying the scanning signals to the scanning lines are provided. The plurality of image signals which have undergone serial-parallel conversion are supplied to the plurality of data lines in units of blocks so as to mainly suppress a driving frequency. In this case, each of the plurality of image signal lines is wired to bypass the data line driving circuit in the vicinity of the data line driving circuit from an external circuit connecting terminal to the sampling circuit. Accordingly, each of the image signal lines has a plurality of bent portions that are vertically bent at the periphery of the data line driving circuit to bypass the data line driving circuit.
Further, vertical conduction terminals are formed, for example, at the periphery of the four corners of the pixel array region so that electrical conduction with the counter substrate, that is, vertical conduction is realized at the peripheral region of the one substrate. In addition, a vertical conduction between the substrates is achieved through a vertical conduction material which includes a conductive paste between a portion opposite to the vertical conduction terminal and the vertical conduction terminal on the counter electrode formed on the one surface of the counter substrate.
However, in the electro-optical device described above, when miniaturization is attempted by changing the size of either side or both sides of the pair of substrates while a current plane layout is maintained for the sampling circuit, the data line driving circuit, the plurality of image signal lines, and, in addition, the vertical conduction terminal, since it is necessary to secure a space for disposing a variety of components described above in the peripheral region of the one substrate, the miniaturization may be difficult. In this case, for example, a substantial design change in the layout of the data line driving circuit may be necessary at the peripheral region of the one substrate, however there may be a possibility of rising in new problems such as an increase in manufacturing cost and a miniaturization which are caused by a change in design.
Further, since noise is generated by an electric field of a vertical bent part being stronger than that of the other linearly wired parts, deterioration of a displayed image quality may occur due to the noise on a display screen.
SUMMARY
An advantage of some aspects of the invention is that it provides an electro-optical device suitable for miniaturization and capable of displaying a high-quality image and an electronic apparatus which incorporates the same.
An electro-optical device according to an aspect of the invention an electro-optical device comprising a first substrate, a second substrate, and an electro-optical material between the first substrate and the second substrate, the first substrate comprising: a plurality of scanning lines and a plurality of data lines that intersect with each other, a plurality of pixel electrodes that are provided so as to correspond to the intersections of the plurality of scanning lines and the plurality of data lines, a sampling circuit that is disposed in a peripheral region positioned around the region in which the plurality of pixel electrodes are arranged, so as to correspond to the plurality of data lines disposed along an extending direction of a first side of the first substrate, a data line driving circuit that is disposed in the peripheral region and closer to the first side than the sampling circuit so as to supply a driving signal to the sampling circuit, at least one image signal terminal disposed in the peripheral region and closer to the first side than the data line driving circuit, the image signal terminal being supplied with a image signal externally, an image signal line that supplies the image signal to the sampling circuit, the image signal line extending from the image signal terminal, bypassing the data line driving circuit, and reaching the sampling circuit, and a vertical conduction terminal disposed near a second side intersecting with the first side of the first substrate, in the peripheral region, vertical conduction terminal enabling electrical conduction between the first substrate and the second substrate, wherein the image signal line has a first straight line portion extending in a direction of the second side and a second straight line portion extending in the direction of the first side, and an intermediate wiring portion connecting the first straight line portion and the second straight line portion, an angle of a corner formed between each of the first straight line portion and the second straight line portion and the intermediate wiring portion is an obtuse angle, and the intermediate wiring portion is wired to pass around the vertical conduction terminal.
According to the electro-optical device of the present invention, during the operation, an image is displayed by applying an applied voltage defined by each pixel potential of the pixel electrodes formed on one substrate such as an element substrate or a TFT array substrate of the pair of substrates and the other counter electrode formed on the other substrate such as the counter substrate, on the electro-optical material (for example, a liquid crystal) which is disposed between the pair of substrates. At this time, for example, each scanning line to which the scanning signal is supplied is selected, and the image signal is supplied to the pixel electrode that is electrically connected to the selected scanning line by interposing the data line and a switching element such as TFT (Thin Film Transistor) intermediated between the data line and the pixel electrode. More specifically, the image signal on the image signal line is sampled by the sampling circuit driven by the data line driving circuit is supplied on the data line, and the image signal is inputted into the pixel electrode at the time when the scanning signal is supplied by interposing, for example, the switching element provided on a pixel unit.
A plurality of external circuit connection terminals are disposed along the first side of the substrate (for example, along an X direction, or an extending direction of the scanning line, i.e. along the direction in which the plurality of data lines are arranged). The plurality of external circuit connection terminals include at least one image signal terminal to which the image signal is inputted externally or from an external circuit. Further, the data line driving circuit or the sampling circuit is disposed in the region near by the first side as viewed from the region (that is, for example, the pixel array region or the image display region) in which the pixel electrode is arranged of the peripheral regions or along the first side mentioned above. The data line driving circuit or the sampling circuit has a plane shape extending rectangularly along the first side.
Here, since the image signal line supplying the image signal to the sampling circuit is also wired to the peripheral region, and the image signal line is extended to the sampling circuit by bypassing the periphery of the data line driving circuit from the image signal terminal against a restriction of a wiring layer constituting the peripheral region. On the other hand, the vertical conduction terminal for taking an electrical vertical conduction in the pair of the substrates is disposed close to the second side (for example, of the sides of the substrates, Y direction or extending direction of the data line, i.e. the side near the side of the substrate along the direction in which the plurality of data lines are arranged) that is adjacent to the first side of the substrate as viewed from the sampling circuit of the peripheral regions. Moreover, the vertical conduction terminals are arranged to avoid the image signal line as viewed in plan against the restriction of the wiring layer constituting the same. That is, the image signal line is disposed around the vertical conduction terminal as viewed in plan.
Accordingly, in order to reduce the peripheral region under the request for miniaturizing the electro-optical device, the vertical conduction terminal may be an obstacle to the image signal line for bypassing the data line driving circuit and passing aside the vertical conduction terminal. Meanwhile, in order to reduce the peripheral region, the image signal line bypassing the data line driving circuit and passing aside the vertical conduction terminal may be the obstacle to the vertical conduction terminal. Moreover, as described in the “Technical Field”, since the image signal line passing aside the vertical conduction terminal bypasses with being perpendicularly curved to the straight line portion that is extended in the first side direction from the straight line portion that is extended in the second side direction and the perpendicularly curved portions exist on the aside of the vertical conduction terminals, the degree of interfering each other as described above increases extremely. In addition, the perpendicularly curved portions may cause deterioration in an image display quality since the noise is formed by the relatively strong electric field as described above.
However, in the present invention, in particular, the image signal line has the intermediate wiring portion that is bent twice in obtuse angle when the line is bent from the one straight line portion extended in the second side direction (i.e., along the direction that the second side extends or along the second side) to the other straight line portion extended in the first side direction (i.e., along the direction in which the first side extends or along the first side) in the portions passing the vertical conduction terminals. Accordingly, since it is possible to make the angular portions of the image signal lines, which is perpendicularly angled, not to exist, the space for disposing the vertical conduction terminals can be secured, in a planar layout. On the contrary, since it is possible to wire the image signal line to bypass the data line driving circuit and pass aside the vertical conduction terminal without a perpendicular angular portion, the space for wiring the image signal line can be secured nearby the vertical conduction terminal, in the planar layout. That is, it is possible to reduce the size of the space that is needed when wiring the vertical conduction terminal and the image signal line. Accordingly, each of the pair of substrates can be miniaturized as large as the space reduced in size.
At this time, by changing the curving form relative to a part of the image signal line and disposing position of the vertical conduction terminal, it is possible to miniaturize the electro-optical device by miniaturizing each of the pair of substrates. For example, it is accomplished without performing drastic design change, for example, the changing overall layout of the image signal line besides changing the disposition of a variety of components such as the data line driving circuit.
Further, since the image signal line is bent at the obtuse angle for at least twice when the line is bent from the one of straight line portion extended in the second side direction to the other straight line portion extended in the first side direction, the electric field generated in the portions related to the bent and curved portion, that is, the curved portion, can be reduced compared to the wiring layout that is perpendicularly bent at a time. With this, it is possible to prevent the generation of the noise for the image signal line and perform the image display having high quality for the electro-optical device.
As a result, according to the electro-optical device of the present invention, it is possible to miniaturize the device and in addition to perform image display having the high quality.
In the electro-optical device, the vertical conduction terminal has a planar shape in which a side facing the intermediate wiring portion extends along the intermediate wiring portion as viewed in plan from the first substrate.
According to the aspect of the present invention, the image signal line has the intermediate wiring portion in the parts passing aside the vertical conduction terminal, and the vertical conduction terminal has a planar shape in which the side facing the intermediate wiring portion extends along the intermediate wiring portion. In other words, the vertical conduction terminal has the planar shape in which the corner that is typically or traditionally perpendicular is cut with being slightly oblique in the side facing the intermediate wiring portion. Therefore, since the image signal line has the portion that is closest to the vertical conduction terminal as the line not as the points in the vicinity of the angular portion, it is possible to secure the space for disposing the vertical conduction terminal more effectively. On the contrary, since the image signal line can be wired to pass aside the vertical conduction terminal having the planar shape extending along the intermediate wiring portion in the intermediate wiring portion, the space for wiring the image signal line can be secured near the vertical conduction terminal more effectively in the planar layout.
At this time, since it is possible to miniaturize each of the pair of substrates by changing the vertical conduction terminal, thereby miniaturizing the electro-optical device, it is considerably advantageous for the practical use.
As described above, the meaning of ‘extending along’ according to the present invention is termed with an intention for including the case in which the side facing the intermediate wiring portion of the vertical conduction terminal is formed to be close to the intermediate wiring portion in the at least one portion other than the case having the side portion for being completely perpendicular to the intermediate wiring portion.
In the electro-optical device, the vertical conduction terminal is formed at a position opposite to a corner adjacent to an angular portion formed by the first side and the second side of the four corners of the first substrate.
According to the form described above, since it is possible to secure the space for disposing the vertical conduction terminal effectively on one corner of the one substrate, the space for wiring the image signal line can be secured effectively. Here, since it is possible to miniaturize each of the pair of substrates by changing the wiring layout of the image signal line without changing the conventional disposition of the vertical conduction terminal, thereby miniaturizing the electro-optical device, it is considerably advantageous for the practical use.
In the electro-optical device, the image signal is formed of N image signals that are converted from serial to parallel (N being a natural number greater than or equal to 2), the image signal line is formed of N image signal lines disposed in parallel, which supply each of the N image signals, and each of the N image signal lines has the intermediate wiring portions disposed between the first straight line portion and the second straight line portion.
According to the aspect of the invention, it is possible to supply the image signal corresponding to the plurality of data line simultaneously by using the image signal converted to serial-parallel. That is, it is possible to simultaneously drive the image signal line of N-series, thereby preventing the driving frequency. Here, particularly, since each of the image signal line of N-series has intermediate wiring portions in the portions passing aside the vertical conduction terminal, the operative effect obtainable from the image signal line according to the invention described above occurs more frequently.
As described above, in addition to the image signal line, the wiring for passing aside the vertical conduction terminal with being curved can be formed to have the intermediate wiring portion as that of the case of the image signal line according to the present invention. For example, the same intermediate wiring portion as that of the case of the image signal line is provided on the curved portion such as power source line or feedback wiring, in the space provided by means of that, whereby the vertical conduction terminal may be disposed. Further, even in this case, it is more preferable that the vertical conduction terminal has the planar shape in which the side facing the intermediate wiring portion extends along the intermediate wiring portion as viewed in plan.
An electronic apparatus according to another aspect of the invention comprises the above-described electro-optical device (however, the aspects are included).
Since the electronic apparatus of the invention includes the above-described electro-optical devices of the invention, various electronic apparatuses, such as projection display devices, televisions, cellular phones, electronic diaries, word processors, view-finder or monitor direct-view-type video cassette recorders, workstations, videophones, POS terminals, and touch panels can be achieved, all of which can achieve a high-quality image display as well as miniaturizing the device. Also, the display device using a liquid crystal device, an electrophoretic device such as an electronic paper, and an EL (electroluminescence) device, and the like can be achieved as the electro-optical device of the invention.
Such operations and other advantages according to the invention will be apparent from the embodiments described below.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
FIG. 1 is a plan view showing the overall configuration of an electro-optical device according to this embodiment of the invention.
FIG. 2 is a cross-sectional view taken along line H-H′ shown in FIG. 1 .
FIG. 3 is a block diagram showing an electrical configuration of an electro-optical device.
FIG. 4 is a schematic plan view showing a configuration of a part surrounded by a dotted line AO shown in FIG. 1 .
FIG. 5 is a schematic plan view showing a configuration of a comparative example.
FIG. 6 is a plan view showing a configuration of a projector, which is an example of an electronic apparatus to which a liquid crystal device is applied.
FIG. 7 is a perspective view showing a configuration of a personal computer, which is an example of an electronic apparatus to which a liquid crystal device is applied.
FIG. 8 is a perspective view showing a configuration of a cellular phone, which is an example of an electronic apparatus to which a liquid crystal device is applied.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
Embodiments of the invention will be described with reference to the accompanying drawings. In each of the embodiments, an electro-optical device of the present invention is applied to a liquid crystal device.
First, the whole configuration of a liquid crystal device according to embodiments of the invention will be described with reference to FIGS. 1 to 3 . FIG. 1 is a plan view showing a liquid crystal device as viewed from a counter substrate side, and FIG. 2 is a cross-sectional view taken along the line H-H′ shown in FIG. 1 . Further, FIG. 3 is a block diagram showing an electrical configuration of a liquid crystal device. Moreover, in FIG. 2 , the dimensions of layers and members have been adjusted to make the layers and members recognizable in the drawings.
In FIGS. 1 and 2 , a liquid crystal device comprises a TFT array substrate 10 and a counter substrate 20 which are disposed opposite to each other. Since a liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20 which are, for example, made of a quartz, a glass and silicon, the TFT array substrate 10 and the counter substrate 20 are bonded together with a sealing material 52 provided in a seal region disposed around an image display region 10 a . Further, an example of the position at which the counter substrate 20 is disposed in relation to the TFT array substrate 10 is shown by a dotted line 200 . In this manner, the counter substrate 20 is disposed on the TFT array substrate 10 so that the circumference lies along the periphery of the seal region, and the vertical conduction terminal 106 formed on the TFT array substrate 10 is disposed at each of the four corners of the substrate.
In order to bond the TFT array substrate 10 and the counter substrate 20 together, the sealing material 52 comprises, for example, an ultraviolet curing resin, a thermal curing resin, or the like. The sealing material 52 is coated on at least one of the TFT array substrate 10 or the counter substrate 20 , and then cured by ultraviolet irradiation, heating, or the like in the manufacturing process. Furthermore, the sealing material 52 may comprise gap materials 56 such as glass fibers or glass beads to be dispersed therein, for setting the gap between the TFT array substrate 10 and the counter substrate 20 to a predetermined value.
A light-shielding frame-shaped film 53 which defines the image display region 10 a is provided on the side of counter substrate 20 in parallel with the inner side of the seal region in which the sealing material 52 is disposed. However, the light-shielding frame-shaped film 53 may be provided as a built-in light-shielding film over part of or the entirety of the TFT array substrate 10 .
In the peripheral region of the image display region 10 a on the TFT array substrate 10 , a data line driving circuit 101 and external circuit connection terminals 102 are provided along one side of the TFT array substrate 10 . A scanning line driving circuits 104 are provided along two sides of the TFT array substrate 10 adjacent to the one side of the TFT array substrate 10 so as to be covered by the light-shielding frame-shaped film 53 . In addition, a plurality of wirings 105 are provided on the remaining side of the TFT array substrate 10 to be covered by the light-shielding frame-shaped film 53 so as to connect the scanning line driving circuits 104 provided on the two sides of the image display region 10 a.
Vertical conduction terminals 106 are provided on the TFT array substrate 10 corresponding to at least one end of the two sides of the image display region 10 a . Electrical conduction can be obtained between the TFT array substrate 10 and the counter substrate 20 by means of the vertical conduction terminals 106 . FIG. 1 shows a configuration in which vertical conductive terminals 106 are provided at the four corners of the image display region 10 a.
In FIG. 2 , on the TFT array substrate 10 , a pixel electrode 9 a is formed on the upper layer of each of the pixel switching TFTs or various types of wiring or the like, and an oriented film 16 is formed on the upper layer. Moreover, the pixel switching element may be constituted by various types of transistors or TFDs rather than TFTs.
On the other hand, counter electrodes 21 facing the plurality of pixel electrodes 9 a are formed in the image display region 10 a on the counter substrate 20 through the liquid crystal layer 50 . That is, a liquid-crystal-retaining capacitance is formed between each pair of the pixel electrodes 9 a and the counter electrodes 21 due to the voltage supplied thereto. A light-shielding film 23 having a lattice shape or stripe shape is formed on the lower layer of the counter electrodes 21 (that is, above the counter electrodes 21 in FIG. 2 ), so that the light shielding film 22 covers the counter electrodes 21 .
A light-shielding film 16 or the light-shielding film 22 formed on the TFT array substrate 10 or the counter substrate 20 is composed of an organic material such as polyimide or the like. In this embodiment, the light shielding film may be formed on either the TFT array substrate 10 or the counter substrate 20 , or the light shielding film may be formed of an inorganic material.
The liquid crystal layer 50 is formed of, for example, one type of nematic liquid crystal or several types of nematic liquid crystals mixed together, and a predetermined orientation state is obtained between a pair of the oriented films.
Although not shown in this embodiment, besides the data line driving circuit 101 and the scanning line driving circuits 104 , a pre-charge circuit for supplying a pre-charge signal of a predetermined voltage level to each of the plurality of data lines prior to an image signal, and an inspection circuit for inspecting the quality and defects of the electro-optical device in the course of manufacture and at the time of shipment may be formed on the TFT array substrate 10 .
Next, the electrical configuration of the above-mentioned liquid crystal device will be described with reference to FIG. 3 . In FIG. 3 , the liquid crystal device has a configuration for controlling the voltage applied to the pixel electrodes 9 a that are disposed in an array in the image display region 10 a in which the TFT array substrate 10 and the counter substrate 20 (not shown) are disposed to face each other through the liquid crystal layer, and for modulating the electric field formed on the liquid crystal layer for each pixel. Accordingly, the amount of light transmitted between the substrates is controlled, thereby permitting a gray-scale display of an image. Moreover, in this embodiment, the liquid crystal device uses the TFT active matrix driving system.
A plurality of pixel electrodes 9 a disposed in matrix and a plurality of scanning lines 2 and a plurality of data lines 3 arranged so as to intersect each other are formed on the image display region 10 a in the TFT array substrate 10 , whereby pixel units corresponding to the pixels are provided. Further, although not shown in this embodiment, a TFT as a pixel switching element in which the conduction and non-conduction is controlled in accordance with the scanning signal that is supplied through the scanning line, or a storage capacitance for storing charge corresponding to the voltage applied to the pixel electrode 9 a is formed between each pair of the pixel electrodes 9 a and the data lines 3 . Further, a driving circuit such as the data line driving circuit 101 is formed on the peripheral region of the image display region 10 a.
The data line driving circuit 101 includes a shift register, a buffer, a lever shifter and the like, and sequentially supplies a transmitted signal to a sampling circuit 7 as a sampling circuit driving signal based on an output of the shift register. More specifically, the data line driving circuit 101 is constituted to subsequently produce and output a sampling signal Si (i being from 1 to n) from the each of the stages based on an X side clock signal CLX (and the opposite signal CLXB) and an X start pulse DX.
The sampling circuit 7 includes a plurality of sampling switches 71 provided in the data lines 3 . Each of the sampling switches 71 samples any one of image signals VID 1 to VID 6 supplied from the external circuit connection terminal 102 through the image signal line 6 as shown in FIG. 3 according to the sampling signal Si output from the data line driving circuit 101 , and then supplies the image signal to the corresponding data line 3 . Each of the switches 71 is formed of a fragmentary-type channel TFT such as one of a P channel type or an N channel type, or a complementary-type TFT.
Here, image signals VID 1 to VID 6 undergo serial-parallel conversion in N phases, that is, six phases (N=6) in this embodiment, when supplied from the external circuit not shown in FIG. 3 to the external circuit connection terminal 102 . These six image signals VID 1 to VID 6 are input to the sampling circuit 7 through a corresponding one of six image signal lines 6 formed in accordance with the image signals VID 1 to VID 6 . In addition, the six image signal lines 6 are formed so as to be curved around the data line driving circuit 101 toward the other end that is electrically connected to the data line driving circuit 101 from the one end that is electrically connected to the external circuit connection terminal 102 in the peripheral region on the TFT array substrate 10 .
Accordingly, in this embodiment, the plurality of data lines 3 wired to the image display region 10 a are driven in data line groups each having six data lines based on six image signals VID 1 to VID 6 . Therefore, by simultaneously supplying the parallel image signals obtained by converting the serial image signals to the plurality of image signal lines 6 , the driving frequency is suppressed.
The scanning line driving circuit 104 is configured to sequentially apply the scanning signal generated on the basis of a Y clock signal CLY (and the opposite signal CLYB) that is a reference clock applied to the scanning signal and a Y start pulse DY to the plurality of scanning lines 2 so as to scan the plurality of pixel electrodes 9 a disposed in matrix in the direction in which the scanning lines 2 are disposed with the image signal and the scanning signal. At this time, in FIG. 3 , a voltage from both ends is simultaneously applied to each of the scanning lines 2 .
Accordingly, when the electro-optical device is driven, each of the scanning lines 2 is selected by supplying a scanning signal, and any one of image signals VID 1 to VID 6 rather than the data line 3 is supplied to the pixel electrode 9 a electrically connected to the selected scanning line 2 .
Moreover, various types of timing signals such as the clock signal CLX or CLY are generated in the timing generator formed on the external circuit and supplied through the external circuit connection terminal 102 to each of the circuits on the TFT array substrate 10 . Further, power necessary for driving each driving circuit is also supplied from the external circuit.
Further, the counter electrode potential LCC is supplied from the external circuit to the signal line from the vertical conduction terminal 106 . The vertical conduction material containing a conductive paste is disposed in a position corresponding to the vertical conduction terminal 106 between the counter substrate 20 and TFT array substrate 10 , and the counter electrode potential LCC is supplied to the counter electrode 21 through the vertical conduction material rather than the vertical conduction terminal 106 . The counter electrode potential LCC is a reference potential of the counter electrode 21 for maintaining a constant difference between the counter electrode potential LCC and the potential of the pixel electrodes 9 a and forming the liquid-crystal-retaining capacitance.
Next, the distinctive configuration of the electro-optical device according to the embodiment will be described more specifically. FIG. 4 is a schematic plan view showing a configuration of image signal line 6 and the vertical conduction terminal 106 , and a disposition relation between such components, and the TFT array substrate 10 and the counter substrate 20 in the part surrounded by the dotted line AO in FIG. 1 .
In this embodiment, at least one part of each of the image signal lines 6 is wired around the data line driving circuit 101 from the one end of the image signal line 6 that is electrically connected to the external circuit connection terminal 102 to the other end of the image signal line 6 that is electrically connected to the data line driving circuit 101 with, the image signal line 6 being led from the first direction F 1 extending from one side of the data line driving circuit 101 to the second direction F 2 that is perpendicular to the first direction F 1 , as viewed in plan from the TFT array substrate 10 . That is, each of the image signal lines 6 is led to the sampling circuit 7 (refer to FIG. 3 ) while bypassing the data line driving circuit 101 . In addition, at least one part of the six image signal lines 6 is led to pass the intermediate wiring portion 6 a and be bent in the second direction F 2 .
In this embodiment, the first direction F 1 is designated as the Y direction or the extending direction of data lines 3 , in other words, the direction in which the plurality of scanning lines 2 are arranged, and it corresponds to the second side direction according to the invention. The second direction F 2 is designated as the X direction or the extending direction of the scanning line 2 , in other words, the direction in which the plurality of data lines 3 are arranged, and it corresponds to the first side direction according to the invention. Further, the first side denotes the side toward the bottom of FIGS. 1 , 3 and 4 , and the second side denotes the side on the left in FIGS. 1 , 3 and 4 .
As shown in FIG. 4 , it is preferable that all of six image signal lines 6 is led through the intermediate wiring portion 6 a , which is one example of the wiring portion wired in an oblique direction, and are bent and led in the direction changing from the first direction F 1 to the second direction F 2 . Here, the intermediate wiring portion 6 a is formed so as to be led in the direction forming an acute angle that is an angle θ formed on a part of the image signal lines 6 extending in the first direction F 1 and be connected to the other portion of the image signal lines 6 extending in the second direction F 2 as viewed in plan from the TFT array substrate 10 . Therefore, the image signal lines 6 in the parts passing the vertical conduction terminal 106 are bent twice in an obtuse angle when those are bent to the other straight line portion along the first direction F 1 from the straight line portion along the second direction F 2 .
In other words, the image signal lines 6 comprise the intermediate wiring portion 6 a connecting the straight line portion of the first direction and the straight line portion of the second direction, and the angle of the corner formed by each of the intermediate wiring portions 6 a of the first and the second direction is an obtuse angle.
In addition, in the peripheral region of the TFT array substrate 10 , the vertical conduction terminal 106 disposed at one corner of the image display region 10 a is provided adjacent to one image signal line 6 having the intermediate wiring portion 6 a of six image signal lines 6 . The vertical conduction terminal 106 has a side disposed along the intermediate wiring portion 6 a of the adjacent image signal line 6 adjacent to the TFT array substrate 10 as viewed in plan. In other words, the vertical conduction terminal 106 has a planar shape whose side facing the intermediate wiring portion 6 a extends along the intermediate wiring portion 6 a as viewed in plan. That is, the vertical conduction terminal 106 has a planar shape in which the angular portion that is conventionally perpendicular is cut so as to be slightly tilted on the side facing the intermediate wiring portion 6 a.
That is, in this embodiment, in the periphery of the data line driving circuit 101 , the image signal line 6 adjacent to at least the vertical conduction terminal 106 of six image signal lines 6 is formed to pass the intermediate wiring portion 6 a and be bent in the direction changing from the first direction F 1 to the second direction F 2 , so that the space for disposing the vertical conduction terminal 106 is secured. In addition, in such space, the vertical conduction terminal 106 having the planar shape whose one side extends along the intermediate wiring portion 6 a is disposed.
FIG. 5 is a schematic plan view showing a configuration of a comparative example corresponding to FIG. 4 . In the comparative example, at least a part of each of the image signal lines 6 is wired to be bent and led the periphery of the data line driving circuit 101 in perpendicular to the direction of from the first direction F 1 to the second direction F 2 , from one end to the other end on the TFT array substrate 10 as viewed in plan.
According to the configuration of the embodiment shown in FIG. 4 compared to the configuration of the image signal line 6 shown in FIG. 5 , the space for disposing the vertical conduction terminal 106 and the respective image signal lines 6 can be reduced. Accordingly, each of the TFT array substrate 10 and the counter substrate 20 can be miniaturized as much as the space reduced in size.
That is, in this embodiment, in the periphery region of the TFT array substrate 10 , by changing the curving form relative to a part of the respective image signal lines 6 and disposing position of the vertical conduction terminal 106 , it is possible to miniaturize the each of the TFT array substrate 10 and the counter substrate 20 , without performing drastic design change such as the changing overall layout of the respective image signal lines 6 besides changing the disposition of various kinds of components such as the data line driving circuit 101 .
Since it becomes further possible to provide a space at the periphery of the curved portion that is bent in the direction of from the first direction F 1 to the second direction F 2 in six image signal lines 6 by wiring all of six image signal lines 6 to pass the intermediate wiring portion 6 a and be bent in the direction of from the first direction F 1 to the second direction F 2 , the other wirings which are wired in a peripheral region on the TFT array substrate 10 can be disposed. Therefore, in the periphery region of the TFT array substrate 10 , since it is possible to reduce the space for disposing the vertical conduction terminal 106 or a variety of wirings, each of the TFT array substrate 10 and the counter substrate 20 can be more miniaturized.
Here, the disposing position of the counter substrate 20 in relation to the TFT array substrate 10 is shown in a dotted line 200 in FIGS. 4 and 5 in a same manner to FIG. 1 . In FIG. 5 , in order to dispose the end portion of the counter substrate 20 and the end portion of the TFT array substrate 10 with the distance d 2 of, for example, 400 μm therebetween, and to dispose the vertical conduction 106 on the right portion of the counter substrate 20 , the counter substrate 20 is disposed in relation to the TFT array substrate 20 .
By this configuration, in FIG. 4 in accordance with the configuration shown in FIG. 5 , since it is possible to reduce the size of the TFT array substrate 10 or the counter substrate 20 as well as the TFT array substrate 10 as much as the space for disposing the vertical conduction terminal 106 and wiring the respective image signal lines 6 , the distance d 1 between the end portion of the counter substrate 20 and the end portion of the TFT array substrate 10 can be set to, for example, approximately 300 μm. In this embodiment, it is possible to reduce the size of the counter substrate 20 as well as the TFT array substrate without changing the disposing position of the counter substrate 20 relative to the TFT array substrate 20 . Accordingly, the vertical conduction terminal 106 is disposed still on the right portion of the counter substrate 20 , even after performing the size change as described above.
By configuration shown in FIG. 5 , since a relatively stronger electric field than that of the other straight line wiring portion is generated in the curved portion that is bent perpendicularly in from the first direction F 1 to the second direction F 2 , the noise may occur.
However, in this embodiment, since the respective image signal lines 6 are formed to pass the intermediate wiring portion 6 a and be bent by interposing the angular portion having the obtuse angle formed from the first direction F 1 to the second direction F 2 , it is possible to prevent the generation of the relatively strong electric field in the respective image signal lines 6 . Therefore, the generation of the noise in the respective image signal lines 6 can be prevented.
Accordingly, in this embodiment, it is possible to miniaturize the electro-optical device as well as perform the image display having a high quality.
In this embodiment described above, on the TFT array substrate 10 , it is preferable that each of the vertical conduction terminals 106 disposed at the four corners of the image display region 10 a is formed to have substantially same shape as viewed in plan.
By this configuration, in the peripheral region on the TFT array substrate 10 , it is possible to dispose the other vertical conduction terminal 106 like the vertical conduction terminal 106 disposed close to the image signal line 6 at the periphery of the data line driving circuit 101 , of the vertical conduction terminals 106 disposed at the four corners of the image display region 10 a . That is, the intermediate wiring portion similar to the case of the image signal line 6 , is provided on the other wirings wired adjacent to the other vertical conduction terminals 106 , for example, the curved portion such as a power source line or a feedback wiring, whereby the vertical conduction terminals 106 can be disposed in the space provided by means of that.
Accordingly, in the periphery region of the TFT array substrate 10 , since it is possible to reduce the space for disposing the vertical conduction terminal 106 and wirings, each of the TFT array substrate 10 and the counter substrate 20 can be further miniaturized.
Furthermore, since it is possible to reduce the curved portions bent perpendicularly to the other wirings described above, the relatively stronger electric field can be prevented in such curved portions. Accordingly, it is possible to prevent the generation of the noise in the other wirings.
Next, an embodiment that the electro-optical device according described above is applied to a variety of electronic apparatuses will be described.
Projector
First, a projector which uses the above-mentioned the liquid crystal device as a light valve will be described. FIG. 6 is a plan view showing a configuration of the projector. As shown in FIG. 6 , the projector 1100 is provided with a lamp unit 1102 having a white light source, such as a halogen lamp, therein. Projection light emitted from the lamp unit 1102 is divided into three primary color light components of R, G, and B by four mirrors 1106 and two dichroic mirrors 1108 which are disposed in a light guide 1104 , and the three primary color light components are introduced to light valves 1110 R, 1110 B and 1110 G.
Here, a configuration of a liquid crystal panel 1110 R, 1110 B and 1110 G is the same as that of the above mentioned liquid crystal device and are driven by primary color signals of R, G and B, respectively, which are supplied from the external circuit (not shown) to the external connection terminal 102 . In addition, light components modulated by the liquid crystal panel are incident on a dichroic prism 1112 from the three directions. In the dichroic prism 1112 , the R light component and the B light component are reflected by 90 degrees, while the G light component passes through straight. After a color image is synthesized from these colors, the color image is projected onto a screen through a projection lens 1114 .
Here, considering the display form by the respective liquid crystal panel 1110 R, 1110 B and 1110 G, it is necessary that the display form by the liquid crystal panel 1110 G is mirror-revered with respect to the display form by the liquid crystal panel 1110 R and 1110 B.
Furthermore, since the light components corresponding to the respective colors of R, G and B are incident on the liquid crystal panel 1110 R, 1110 B and 1110 G, respectively, through the dichroic mirrors 1108 , no color filter is provided.
Mobile Computer
Next, an example in which the above-mentioned electro-optical device is applied to a mobile personal computer will be described. FIG. 7 is a perspective view showing a configuration of a personal computer. In FIG. 7 , the computer 1200 is provided with a main body 1204 having a keyboard 1202 and a liquid crystal display unit 1206 . The display panel 1206 is provided with a backlight at the back surface of the above-mentioned liquid crystal device 1005 .
Cellular Phone
In addition, an example in which the above-mentioned liquid crystal panel is applied to a cellular phone will be described. FIG. 8 is a perspective view showing a configuration of a cellular phone. In FIG. 8 , the cellular phone 1300 is provided with a plurality of operation keys 1302 , and a reflective liquid crystal device 1005 . Moreover, the reflective liquid crystal device 1005 is also provided with a front light at the front surface thereof if necessary.
In addition to the apparatuses shown in FIGS. 6 to 8 , examples of electronic apparatuses may include liquid crystal televisions, view-finder-type and monitor-direct-view-type video tape recorders, car navigation systems, pagers, electronic diaries, electronic calculators, word processors, workstations, videophones, POS terminals, and touch panels. Then, it is needless to say that the electro-optical device according to the above embodiment can be applied to these electronic apparatuses.
The present invention is not limited to the above embodiment, and appropriate modification can be made within the scope of the present invention, which can be found from the claims and the specification. The technical field of the present invention also includes an electro-optical device and an electronic apparatus according to modified embodiments.
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An electro-optical device comprising an image signal line that supplies an image signal to a sampling circuit, the image signal line extending from an image signal terminal, bypassing a data line driving circuit, and reaching the sampling circuit. The image signal line has a first straight line portion extending in one direction, a second straight line portion extending in another direction, and an intermediate wiring portion connecting the first straight line portion and the second straight line portion. An angle of a corner formed between the first straight line portion, the second straight line portion, and the intermediate wiring portion is an obtuse angle. The intermediate wiring portion is wired to pass around a vertical conduction terminal. Detailed information on various example embodiments of the inventions are provided in the Description of Exemplary Embodiments below, and the inventions are defined by the appended claims.
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BACKGROUND
1. Field
This invention relates to improvements in ferromagnetic filters and, in particular, to a method for increasing the bandwidth while reducing spurious responses in such filters.
2. Prior Art
A ferromagnetic filter in its rudimentary form, consist of a coupling loop positioned close to a sphere of a ferromagnetic material located in a magnetic field. The ferromagnetic material, usually yttrium-iron-garnet (YIG), can be made to produce a principal resonance at a frequency determined by the strength of the magnetic field. The resonant frequency is given by fo=γHo where Fo is the resonant frequency, γ is the gyromagnetic ratio, 2.8 MHz/oersteds, and Ho is the applied magnetic field in gauss.
Bandwidths of such devices are usually small, typically less than 35 MHz about the center frequency. Increasing the bandwidth of these filters has been a long-standing objective. In prior art approaches to produce wider bandwidths, the coupling between the loop and the sphere has been increased by bringing the loop closer to the sphere or a strap with lower inductance has been substituted for the more commonly used single wire loop. These approaches have resulted in an increase in both crossing and tracking spurious responses. Tracking spurious are spurious responses which follow the principal resonance of the sphere as it is tuned across a frequency range. Crossing spurious are those which do not tune at the same rate as the principal resonance mode and therefore cross through the principal resonance mode as it is tuned through a frequency range.
Prior approaches designed to reduce the spurious responses have included decreasing the unloaded Q of the YIG sphere by means of roughening the surface of the sphere; however, this process increases the insertion loss at the principal resonance.
There are a number of additional problems associated with prior art YIG filters which may be explained with reference to a rudimentary YIG filter, such as that shown in FIG. 4. In this Figure, an input port 401 is connected to an output port 402 by way of a coupling loop 403, which surrounds a YIG sphere 404. Note that in all figures, dots on a line about a YIG sphere represent the initiation or termination of a coupling loop. For example, in FIG. 4B, the dots represent the initiation and termination of loop 403. In the operation of this device, a signal placed on the input port is transmitted to the output port. Signals which are at the principal resonance of the sphere are rejected and returned to the input port. In this mode of operation, the device functions as a band-stop filter.
The length of the line from the input port to the output port forms an inductance that is an integral part of the band-stop filter. This inductance limits the range over which the band-stop filter can operate because it functions as a portion of a separate low-pass filter structure. Increasing the inductance reduces the high frequency cutoff of the low-pass filter which, in turn, limits the high frequency response of the YIG filter.
One prior art approach, intended to increase the bandwidth of the YIG filter at its principal resonance, is to lower the external Q of the sphere and loop by increasing the coupling between the two. This is done by increasing the turns of the coupling loops about the sphere. The disadvantage of this approach is it increases the series inductance of the line between the input and output ports and consequently reduces the high frequency cutoff off the low-pass filter section formed by this line.
The desirability of reducing the line inductance in band-stop filters has been generally recognized; however, it has not been as well recognized for bandpass filter. Attempts to reduce the line inductance by again substituting a wide strap for the usual single wire loop has resulted in the increases spurious response described previously. As an alternative to the strap, a number of parallel, closely spaced or touching wires has also been used with similar unsatisfactory results.
Practical prior art ferromagnetic resonator filters, which have been, for the most part, band-pass filters, usually make use of the same components described in connection with the band-stop filter of FIG. 4. That is, they make use of a coupling wire for coupling to the ferromagnetic material, which is typically in the shape of a sphere. The coupling wire is often formed into a loop around the sphere for increased coupling to the sphere. The coupling loops and spheres are housed in a structure which provides RF shielding between stages, but which allows the coupling wires to pass from stage to stage through the shield. A stage, as used herein is a basic filter section comprising for example one YIG sphere and its associated circuitry which is typically one or more coupling loops positioned about the sphere. In FIG. 2, loop 206 positioned about YIG sphere 201 comprise a first stage, loop 207 and sphere 202 comprise a second, and loop 208 and sphere 203 comprise a third.
Interstage coupling is accomplished with a wire with two loops formed along it, both ends of this wire being electrically connected to the RF housing or ground. Input and output coupling is accomplished with a wire loop connected from the input or output transmission line to the RF housing or ground. The coupling loops in each stage are positioned orthogonally with respect to one another to minimize coupling from one loop to another.
It is generally known that a band-pass filter can be designed by using input and output stage external Q and interstage coupling coefficients because the internal Q is relatively high in comparison to the Q of the external circuitry. The coupling values required are available from published tables and are related to the basic filter network. Thus, it is possible to attain the band-pass filter response desired from a ferromagnetic filter by adjusting the coupling loops close to the sphere, or by using a sphere which is large compared to the diameter of the coupling loop. Unfortunately, the spurious problem encountered with band-stop filters is present in band-pass filters as well. Both of these approaches to wide bandwidths lead to increased coupling to spurious modes. The spurious modes are undesirable in a band-pass filter because the tracking spurious modes produce additional passbands which degrades the filter out-of-band rejection and the crossing spurious modes produce additional passband insertion loss. Coupling to these spurious modes can be reduced by decreasing the unloaded Q of the ferromagnetic sphere, but this also causes increased passband insertion loss and a reduction in filter bandwidth. Thus, increased bandwidth in prior art devices results in degraded filter performance.
SUMMARY
In the present invention, spurious responses have been reduced and bandwidth has been increased in YIG filters without increasing loss by means of a multi-conductor loop in which the multi-conductors are separated from one another.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a single stage ferromagnetic band-stop filter using a multi-conductor coupling loop.
FIG. 2 illustrates a three stage filter using a multi-conductor coupling loop in two of the three stages.
FIG. 3 illustrates a single stage band-pass ferromagnetic filter using multi-conductor coupling loops.
FIG. 4 illustrates a conventional single stage ferromagnetic filter.
FIG. 5 illustrates an equivalent input or output stage of a band-pass filter.
FIG. 6 illustrates an equivalent interstage of a band-pass filter.
DETAILED DESCRIPTION OF THE INVENTION
In the band-stop filter of FIG. 1, a drive circuit 101 supplies a drive signal to a winding 103 located about a core 102, to produce a magnetic field 109 directed to pass through a ferromagnetic sphere 106. An input port 104 is connected to an output port 105, by way of a loop 107 which encircles sphere 106. The sphere and loop are located in a cavity 108 of a frame 109.
FIG. 1A represents a cross sectional view of the side of the band-stop filter, while FIG. 1B represents a top view. It can be seen in FIG. 1B that the coupling loop is divided into two separate conductors, 107A and 107B.
In the operation of the device in FIG. 1, a signal placed on the input port 104 is delivered to the output port 105. Energy at the frequency of the resonant sphere is reflected by the sphere back to the input port, creating a band-stop filter action at the principal resonance frequency of the sphere.
The conductors 107A and 107B are separated by at least the thickness of one of the conductors. The two conductors provide a reduction in the inductance in the line between ports 104 and 105 over a single conductor line, while providing a lower spurious response than is usually encountered with either a strap or a single conductor loop, for the same equivalent coupling bandwidth. The reduced inductance of the multiple conductors produces a lower external Q device and, therefore, increases the bandwidth. With the present invention, bandwidths have been increased by approximately 50 percent over that achieved with prior art devices.
In order to explain the benefit of the invention, the mathematics which describe its operation are introduced below. The external coupling to a YIG shpere is expressed by: ##EQU1## Where: Qe=external Q of the resonator
r=radius of the coupling loop in meters
Ra=external load impedance in ohms
N=number of turns
μ o =permeability of free space, 1.256×10 -6 henries/meter
Vm=volume of the YIG sphere in meters 3
γ=gyromagnetic ratio, 1.759×10 11 (MKS units)
Ms=saturation magnetization of the material (MKS units)
ω o =resonant frequency of the resonator in radians/second
Ls=self inductance of the coupling loop in henries
The derivation of the above expression is based on the representation of the YIG resonator as an equivalent lumped parallel resonate circuit, formed of conventional inductors and capacitors, separate from the coupling loop inductance. The quantity in the first bracket then represents an equivalent circuit for the YIG resonator. The equivalent circuit values for the inductor and capacitors can be obtained by setting L s equal to zero in Equation 1. ##EQU2## An equivalent circuit for an input stage is shown in FIGS. 5A and B, while an equivalent circuit for two YIG resonators coupled by wire loops is shown in FIGS. 6A and B.
The schematic circuit of FIG. 5A comprises a generator 501, a generator source impedance 502, a ferromagnetic sphere 504, and a loop 503 coupled to the ferromagnetic sphere.
FIG. 5B is a lumped element equivalent of the circuit shown in FIG. 5A. This circuit comprises a generator 501, a generator source impedance 502, a self-inductance of the loop 504, an equivalent inductance of the ferromagnetic sphere 506, and an equivalent capacitance of the ferromagnetic sphere 505.
FIG. 6A is a schematic of the interstage coupling of a band-pass filter. This circuit comprises a first loop 601, a first ferromagnetic sphere 602, a second loop 604, and a second ferromagnetic sphere 603.
FIG. 6B is a lumped element equivalent circuit for the circuit of FIG. 6A, wherein inductor 605 and capacitor 606 represent the resonance of sphere 602 and the inductor 608 and capacitor 609 represents the resonant circuit of sphere 604. The inductance 607 represents the combined series inductance of loops 601 and 604.
It can be seen that the equivalent circuit for a YIG band-pass filter is an inductively coupled filter. The coupling between stages of an inductively coupled filter is given by: ##EQU3## Where: L i , i+1 =coupling inductance between stages i and i+1
L i =inductance of the inductor in the i th stage
L i+1 =inductance of the inductor in the i th +1 stage
BW=bandwidth of the filter in radians/second
The inductance L i , i+1 is the self inductance of the coupling wire. At microwave frequencies this coupling wire has electrical length and its inductance is expressed by:
L.sub.i, i+1 =(Zo/χ.sub.o) sin (βλ) Equation (4)
Where:
Zo=equivalent characteristic impedance of the coupling wire within the structure chosen
β=propagation constant in radians/meter
λ=length of the coupling wire in meters
It now becomes apparent that the interstage coupling in a loop coupled YIG filter is highly dependent upon the characteristic impedance and length of the coupling loop. Prior art devices typically use a single 0.003 inch diameter wire in a 0.060 inch diameter cavity, and this structure has a characteristic impedance of approximately 160 ohms. Attempts to increase the coupling in prior art devices consisted of bringing the coupling wire closer to the sphere. This resulted in increased coupling to spurious responses. Since the above mathematical explanation of the parameters involved in the coupling to YIG resonators is not generally available, designs of prior art devices have not made use of all of the coupling parameters involved. In fact, most prior art design practice is based, primarily, upon previous experience of the practitioner and upon an empirical approach, rather than a mathematical or quantitive one. The mathematics presented provides a method for designing the filter input and output couplings, as well as interstage couplings which are required for a particular filter passband response. These equations show the importance of the coupling loop length and characteristic impedance on filter bandwidth.
This invention effectively increases the coupling to YIG resonators by providing a decrease in the characteristic impedance of the coupling structure. This is accomplished through a construction which uses multiple and parallel conductors. These conductors are spread apart, which further reduces the characteristic impedance, but with an accompanying decrease in the coupling to spurious modes compared to close space conductors.
It is now believed that coupling to spurious modes is enhanced by a conductive surface near the YIG sphere, such that an image of the YIG sphere can exist in this conductor. Crossing spurious responses are observed only at the main resonance. That is, they are not excited at frequencies away from the main resonance. It would appear that the main resonance mode couples to the spurious responses, rather than the coupling loop itself coupling directly to the spurious modes. An explanation for this phenomenon is provided by an image surface which allows an image resonator to exist. It is generally known that an additional sphere in a coupling structure will cause coupling to spurious modes. This explains why prior art devices, which use coupling ribbons, straps, large diameter wire, or other large conductors, also have strong coupling to crossing spurious modes.
This invention effectively reduces or eliminates coupling to crossing spurious modes, as well as other spurious modes. The use of multiple conductors spread apart, in effect, breaks up the image plane and reduces the coupling to spurious modes.
The benefit of the invention is apparent in the design and performance of YIG band-pass filters. Prior art devices, using single wire conductors, and doped material to avoid low-level coincidence limiting provide a maximum filter bandwidth of 25 to 4 MHz over a 2 to 18 GHz tuning range. With the present invention, filter bandwidths of greater than 50 MHz are consistently attained, along with reduced spurious responses.
The new invention is also a benefit in the performance of YIG band-stop filters. The coupling to a YIG band-stop filter section is also given by equation 1, but the term Ra becomes equal to twice the system impedance because the coupling loop is in series with the source and load impedance. Since the coupling loop self-inductance is in series with the transmission path, one of the primary design problems is the attainment of a wide impedance match in a band-stop filter. In general, this requires coupling loops with less self-inductance, and a lower characteristic impedance for the coupling loop structure than is used in band-pass filters. Prior art devices typically use a large conductor cross-section, such as relatively large diameter wire, for the coupling loop, but this approach contributes to the coupling to spurious modes, as explained by the image surface concept.
The use of the multiple, and separated, conductor coupling loop structure provides the reduced coupling loop self-inductance required in a band-stop filter along with reduced coupling to spurious responses.
FIG. 2 is a drawing of a multistage band-stop filter in which FIG. 2A illustrates a side view of this filter, while FIG. 2B illustrates a top view. In these figures, an input port 204 is coupled to an output port 205 by means of cascaded coupling loops 206, 207, and 208, which encircle ferromagnetic spheres 201, 202, and 203, respectively. It can be seen in FIG. 2B that loop 207 is comprised of conductors 207A and 207B, and coupling loop 208 is comprised of conductors 208A and 208B.
In the operation of this filter, a signal placed on port 204 arrives at port 205, except for power reflected at the resonant frequency of three spheres.
It is possible to combine single solid wire loops with multiple conductor loops, as can be seen in this Figure. The use of different number of conductors in a loop varies the inductance of the loop. This adjustment in the inductance can be used as an aid in varying the impedance of each section as required.
FIG. 3A illustrates a side view of a simple bandpass filter employing the present invention, while FIG. 3B illustrates a top view of this filter. In these Figures, input port 301 is connected to ground by way of loop 302, which encircles YIG sphere 305. Output port 303 is connected to ground by way of loop 304. In FIG. 3B, it can be seen that both loops 304 and 302 each comprise two conductors, A and B, and that loop 302 passes over the top of the sphere, while loop 304 passes beneath the sphere. The two loops are oriented in a generally orthogonal manner. A signal supplied to input port 301 is fed to loop 302 where it is coupled through the sphere at the principal resonance frequency to the output loop 304 and then is fed to the output port 303. Typically two conductor loops are used and the conductors are spaced apart by at least the thickness of one of the conductors. A method for predictably producing the proper spacing in production is to use a strip conductor and by means of photo etching techniques divide the strip into multiple conductors.
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Ferromagnetic resonant devices include special coupling loops formed of multi-conductor transmission lines to increase the RF electromagnetic coupling to the ferromagnetic resonators, while decreasing coupling to spurious resonant modes.
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BACKGROUND OF THE INVENTION
1. Field Of The Invention.
This invention relates to a method for the chemical purification of enzymatic proteins. Known chemical separation methods for enzymatic proteins are usually based upon differential precipitation of the preferred enzyme from other undesirable enzymes and impurities which contaminate the mixture. Where an enzyme is not separable from other impurities found in the enzyme mixture, in many cases this renders it useless in particular applications. For example, the enzyme, glucose oxidase, is usually found in the presence of the enzyme catalase. Glucose oxidase contains a carbohydrate moiety and is thus a carbohydrate containing enzyme. Glucose oxidase catalyzes the reaction of glucose to form gluconic acid and hydrogen peroxide. Catalase catalyzes the degradation of hydrogen peroxide. In many applications glucose oxidase is used to generate hydrogen peroxide to quantify the glucose substrate. When catalase is present the hydrogen peroxide generated by the glucose oxidase is partially destroyed. The method is thus less accurate and in many cases totally ineffective. Other examples are known where one enzyme is extremely difficult to separate from another and this inability to separate the enzymes limits the utility of the preferred enzyme.
Additionally, presently known methods of separating enzymes are time consuming, possibly on the order of hours, usually require a number of different reagents to complete the separations process, and result in a low yield of the separated preferred enzyme. These drawbacks in the cases where separation is possible as well as the circumstance where separation is not completely possible, or possible only with very undesirable levels of contaminants, are overcome by the present invention.
2. Description Of The Prior Art.
Most of the known prior art relating to the chemical separation of enzymes from other enzymes or other chemical impurities in a mixture are concerned primarily with three methods of separation. The first method is differential precipitation, using water-miscible solvents. U.S. Pat. No. 3,616,232 discloses the use of water-miscible alkanols, alkylketones, and cyclic ethers as precipitating agents to separate proteins. The solution containing the proteins is mixed with the water-miscible solvents, in which the enzymes themselves are not soluble, in a particular volume to volume fraction. After the solvents are added, the mixture is shaken, and at particular volume to volume fractions different proteins fractionate from the mixture. Similarly, U.S. Pat. Nos. 3,645,851 and 2,926,122 disclose the use of low molecular weight alcohols to differentially precipitate proteins from an aqueous solution, and then collect the precipitated proteins. Most of these differential solvent precipitation methods require precise balancing of solvent volumes, solution temperatures, and the time the solutions are allowed to stand. These methods always involve the inherent risk of solvent denaturation of the enzyme or protein which is preferred and is being recovered. Additionally, these methods usually take long periods of time and in many cases have low yields of the preferred enzyme.
The second commonly used separation method of enzyme or protein purifcation involves differential precipitation without the use of solvents. In these methods, generally speaking, an inorganic salt or organic base is added to a solution of the preferred enzyme. The preferred enzyme or the contaminating enzymes are differentially precipitated from the solution. The precipitate or the supernatant liquid, whichever contains the preferred enzyme, is then processed by known chemical methods, for example, gel filtration. These methods also usually require long periods of time, the separation and handling of precipitates, and generally use a number of reagents. For example, U.S. Pat. No. 3,930,953 discloses the precipitation of glucose oxidase from an aqueous solution by mixing the glucose oxidase solution with diaminoethoxyacridine lactate. The lactate forms a precipitate with the glucose oxidase. The solution is allowed to stand for as long as twenty-four hours at low temperatures, whereupon the lactate-protein complex precipitates out of solution. The complex is then recovered and destroyed by the addition of large quantities of chloride salts and the resultant free glucose oxidase is separated by conventional chemical methods. Similarly with U.S. Pat. Nos. 3,265,587 and 3,269,918 the desired protein is precipitated or the impurities are precipitated and the fraction containing the desired protein is further processed by conventional chemical methods. Typical precipitating reagents are calcium, barium, and ammonium sulfates.
The third type of known separation method comprises contacting the enzyme mixture with a solution containing an insolublized coenzyme, which is reacted with respect to one or more of the enzymes in the mixture. The enzyme in the mixture becomes attached to the insolubilization support through the coenzyme. The support is removed from the mixture with the enzyme attached thereto, and the enzyme is eluted from the support for further processing.
None of the prior art discussed above discloses a method for the separation of carbohydrate containing proteins wherein the carbohydrate portion of the carbohydrate containing preferred enzyme is modified. The process, according to the present invention, is very rapid compared to methods known in the art. Also, the method is relatively inexpensive and has a very high yield of the preferred enzyme. In many cases, substantially all of the preferred enzyme is isolated from impurities, with yields of the preferred enzyme on the order of 90% recovery and above.
Additional references to precipitation methods of purification of proteins of enzymatic types are: "The Oxidation of Glucose and Related Compounds by Glucose Oxidase from Aspergillus niger". John H. Pazur and Kjell Kleppe, Biochemistry, Vol. 3, pp. 578-83 (1964); "Purification and Properties of the Glucose Oxidase from Aspergillus niger" Bennett E. P. Swoboda and Vincent Massey, Journal of Biological Chemistry, Vol. 240, pp. 2209-15 (1965); "Comparative Studies on the Glucose Oxidase of Aspergillus niger and Penicelium amagasakiense" Satoshi Nakamura and Smiko Fujiki, Journal of Biochemistry, Vol. 63, pp. 51-8 (1968); and "The Glucose Oxidase Mechanism, Interpretation of the pH Dependence", Michael K. Weibel and Harold J. Bright, Journal of Biological Chemistry, Vol. 246, pp. 2734-44 (1971).
It has been recognized that carbohydrate moieties on carbohydrate containing enzymes can be treated with oxidizing agents preparatory to immobilization by covalent bonding to supports. See, "The Immobilization of Glucose Oxidase. Activation of its Carbohydrate Residues", O. R. Zaborsky and J. Ogletree, Biochem. Biophys. Res. Commun., Vol. 61, pp. 210-16 (1974).
Also, the oxidation of carbohydrate moities on proteins has been accomplished in order to determine kinetic and structural properties of proteins in solution. For examples of such determinations see, "A Role of the Carbohydrate Moiety of Glucose Oxidase: Kinetic Evidence for Protection of the Enzyme from Thermal Inactivation in the Presence of Sodium Dodecyl Sulfate", S. Kakamura and S. Hayashi, FEBS Letters, Vol. 41, pp. 327-9 (1974), and "The Composition and Structure of Carbohydrate Moiety of Stem Bromelain", Y. Yasuda, N. Takahashi, and T. Murachi, Biochemistry, Vol. 9, pp. 25-32 (1970).
Based on the above discussed art, no method is believed known for the separation of a carbohydrate containing enzymatically active protein from a contaminating protein or enzyme by the modification of the carbohydrate moiety according to the method of the present invention.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a method to separate carbohydrates containing enzymes from contaminating enzymes and in particular, the enzyme catalase.
Another object of this invention is to provide an enzyme separation method whereby carbohydrate containing enzymes may be rapidly separated from contaminating enzymes.
A further object of this invention is to provide a method for separating carbohydrate containing enzymes from contaminating enzymes using a minimum of externally supplied reagents.
An additional object of this invention is to provide the rapid low cost method described above which is capable of producing high yields of the carbohydrate containing enzyme with high activities in the final isolated enzymes.
These and other objects are accomplished by a method for separating a carbohydrate containing enzyme from a contaminating enzyme, particularly catalase, comprising the steps of, mixing the solution containing the carbohydrate containing enzyme with a carbohydrate modifying reagent. The solution is allowed to react for a period of time sufficient to allow the modifying reagent to modify the carbohydrate attached to the enzyme. The modified carbohydrate containing enzyme and contaminating enzyme are then subjected to conventional method of chemical separation. Particularly preferred is gel filtration chromatography, which has been demonstrated to give very high yields of the preferred protein at high activity levels.
Note that a feature of this invention is that certain carbohydrate containing enzymes (or proteins which are nonenzymatic), for example, glucose oxidase, have been discovered by this method to be more readily separable from contaminating enzymes such as catalase when the carbohydrate moiety is modified.
The method according to the present invention shows excellent reproducibility over wide ranges of catalase and glucose oxidase concentrations, and can be used with relatively inexpensive, readily available laboratory reagents.
DETAILED DESCRIPTION OF THE INVENTION
The present method is particularly useful and successful in the separation of glucose oxidase, a carbohydrate containing enzyme, in impure form from contaminating catalase. The discussion will be directed particularly toward experimental results and information concerning the proteins glucose oxidase and catalase, but it is to be understood that the method of the present invention is equally applicable to any carbohydrate containing enzymatic protein or nonenzymatic protein which can be treated in accordance with the method of the invention.
Glucose oxidase has a carbohydrate moiety which is approximately 16% by weight of the glucose oxidase molecule in its native state.
It has been discovered in the present invention that there seems to be some form of molecular interaction between the glucose oxidase/carbohydrate molecule and the enzyme catalase. It is believed that this interaction causes much of the difficulty which is traditionally encountered when attempting to purify glucose oxidase from catalase. While not being bound by any theory, it is clear from the experimental evidence presented hereinafter that glucose oxidase when treated according to the method of the present invention is more effectively separable from catalase than by previous methods. The method of the present invention works equally well with members of the enzyme class known as dehydrogenases.
In a preferred embodiment of the invention a solution of the glucose oxidase is treated with a hydrolytic enzyme which is capable of at least partially hydrolyzing the carbohydrate moiety attached to the main body of the glucose oxidase molecule. In any case, the hydrolytic enzyme reacts with the carbohydrate moiety for a controlled period of time. If the reaction time is extended long enough the entire carbohydrate moiety can be removed from the carbohydrate containing enzyme. However, in other instances, the time may be shortened to a time that allows only sufficient enzymatic modification of the carbohydrate moiety to achieve the results of facilitating separation of the glucose oxidase from the catalase. Enzymes which have shown good results, as hydrolytic enzymes to hydrolyze the carbohydrate moiety are dextranase, amylase, glucoamylase and cellulase. Dextranase has been shown particularly useful in the preferred embodiment and will be exemplified hereinafter.
To employ the method, a solution of the glucose oxidase is incubated with a solution containing dextranase or one of the other enzymes capable of at least partially hydrolyzing the carbohydrate moiety of the glucose oxidase, for example, an amylase, cellulase or glucoamylase. The incubation solution is typically at about pH 3.8 and between 35° and 40° C. After the reaction is started the mixture may be allowed to stand overnight unattended and processed the next day. After the incubation is completed the solution containing the glucose oxidase, now having a modified carbohydrate moiety, is applied to a gel filtration chromatography column and fractions eluted from the column are analyzed at 254 nm to detect the glucose oxidase fraction. It has been demonstrated that glucose oxidase on the order of 95% purity may be obtained using conventionally available Sephadex or Sepharose columns. Sephadex and Sepharose gels are cross-linked highly hydrated polymeric dextran gels.
In an alternative embodiment of the present invention, the carbohydrate moiety on the glucose oxidase is treated with sodium periodate. The sodium periodate is believed to partially oxidize the carbohydrate moiety, thereby, it is assumed, reducing its role in causing the catalase to interact with the glucose oxidase.
In the alternative embodiment a solution of the glucose oxidase with the carbohydrate moiety attached is mixed with sodium periodate until the periodate concentration is approximately 1/10th molar. The solution is stirred for about two hours at approximately 0° C. The reaction is quenched by the addition of 15 ml of ethylene glycol. The reaction may be quenched in any acceptable fashion. The resultant solution is believed to contain glucose oxidase with its carbohydrate moiety partially oxidized. This mixture is eluted from a Sephadex or Sepharose column as is the material from the enzymatic hydrolysis embodiment. The material thus eluted was found to be on the order of 90% pure with respect to glucose oxidase.
To demonstrate the effectiveness of the present method in separating a carbohydrate containing protein, such as glucose oxidase from catalase, reference is made to Tables I, II and III. The Tables each show the number of fractions collected upon elution of the material from the designated procedures from a gel filtration chromatography column. The first column of each Table indicates the fraction number which is received from the column. The second column indicates the absolute absorbance value for each fraction, the third column indicates the activity level of the glucose oxidase for each fraction, and the fourth column indicates the catalase activity for each fraction.
The materials used in Table I were a column packed with Sepharose 4 B gel onto which was applied approximately 5 ml of glucose oxidase solution (Miles-Servac, Aspergillus niger). The enzyme was eluted using 5×10 -3 molar succinic acid buffer and 5×10 -3 molar EDTA, at about pH 5. The fractions are collected by allowing the fluids placed on the column to elute and collect separate fractions in separate analysis tubes.
Table I shows the results of the chromatography of glucose oxidase which is contaminated with catalase when the solution has not been treated according to either embodiment of the present invention. The data shows that there is a very inefficient separation of the glucose oxidase from the catalase using conventional gel chromatography alone. Each fraction of Table I represents 10 ml of eluent from the column. As indicated by Table I, 3 fractions are found to contain substantial amounts of glucose oxidase. Each of these fractions also has substantial amounts of contaminating catalase. Fraction 3, the fraction lowest in catalase activity, shows approximately 20% of the total enzymatic activity as being due to catalase. This high catalase contamination value is typical of the level of catalase contamination when normal gel chromatography methods are used. This Table serves to show that glucose oxidase purified using gel chromatography is not effectively purified, and not suitable for many uses.
TABLE I______________________________________GEL FILTRATION WITHOUT MODIFICATION Absorbance Glucose Oxidase CatalaseFraction at 254 nm U/mg Protein U/mg Protein______________________________________1 0.010 47 142 0.030 18 143 2.0 19 5______________________________________
The materials and methods used to generate Table II include the use of 10 ml fractions of glucose oxidase (Miles-Servac, Aspergillus niger) which are added to 3 to 5 ml of dextranase solution (5 mg per ml, Dextranase Products, Ltd.). The pH of the solution was adjusted to about 3.8 and was allowed to incubate overnight at a temperature of between 35° and 40° C. The reaction was monitored by an oxygen monitoring electrode. As the carbohydrate is hydrolyzed by the dextranase free glucose is liberated. The glucose oxidase then degrades the glucose to form gluconic acid and hydrogen peroxide, using molecular oxygen found in the solution. As the oxygen concentration decreases this indicates hydrolysis of the carbohydrate and indicates approximately when the reaction has gone to completion. Approximately 5 ml of the glucose oxidase solution was applied to a column containing Sepharose 4 B material. As indicated by the results the improved separation of glucose oxidase is substantial.
Table II shows the effect on gel filtration purification of the modification of the carbohydrate containing enzyme which has been incubated with a dextranase enzyme to at least partially hydrolyze the carbohydrate moiety on the glucose oxidase. The fractions in Table II are again 10 ml fractions, with the same column headings as Table I. The difference between the experiments represented by Tables I and II is that the dextranase treatment sample shows very much better separation of the glucose oxidase from the catalase. Notice that fractions 2, 3 and 4 are extremely high in glucose oxidase activity while being extremely low in catalase activity. Based on activity measurements, the fraction collected in tubes 2 and 4 are about 95% pure in glucose oxidase, while the fraction collected in tube 3 is about 94% pure in glucose oxidase. This indicates that the dextranase treatment according to the present invention does in fact substantially increase not only the yield of glucose oxidase, which may be gained from purification process, but also substantially increases the relative purity of the glucose oxidase isolated. Notice that the improvement over the results of Table I is approximately 15%, representing a substantial advantage over the known methods.
TABLE II______________________________________GEL FILTRATION WITHDEXTRANASE MODIFICATION(CARBOHYDRATE HYDROLYSIS) Absorbance Glucose Oxidase CatalaseFraction At 254 nm U/mg Protein U/mg Protein______________________________________1 .003 74 552 .021 38 1.83 .019 48 34 .009 99 4.95 .008 63 51______________________________________
The materials and methods used to generate Table III include the use of about 30 ml of glucose oxidase solution, to which is added enough sodium periodate to bring the solution to 0.1 M in periodate. The solution is allowed to react for about two hours at about 0° C. and then applied to the column.
Table III represents the alternative embodiment of the present invention, using an inorganic oxidizing agent as the chemical oxidant, in this case sodium periodate. The headings of each column are the same as Tables I and II with the exception that the adsorbance is measured at 280 nm and the fraction size is 13 ml. As indicated by fractions 4, 5 and 6, glucose oxidase may be obtained which is approximately 91%, 89%, 86% pure as compared to the maximum results of approximately 80% using standard gel filtration techniques. This indicates again the substantial increase in the purity of glucose oxidase when processed according to the methods of the present invention.
TABLE III______________________________________ GEL FILTRATION WITHSODIUM PERIODATEMODIFICATION (PARTIALOXIDATION) Absorbance Glucose Oxidase CatalaseFraction at 280 nm U/mg Protein U/mg Protein______________________________________ 1 0.165 18 502 0.360 21 293 0.340 31 184 0.300 77 85 0.250 46 66 0.190 60 107 0.200 39 108 0.260 30 89 0.130 56 1910 0.10 59 22______________________________________
The following Examples illustrate the procedures used to produce the purified glucose oxidase according to the methods of the present invention.
EXAMPLE I
Ten ml of glucose oxidase (Miles-Servac, Aspergillus niger) solution was added to 3 to 5 ml of dextranase solution (5 mg per ml, Dextran Products, Ltd.). The pH of the solution is adjusted to approximately 3.8 and the temperature adjusted to between 35° and 40° C. The oxygen concentration of the reaction mixture is monitored overnight and when the oxygen concentration has decreased to a significant level, 5 ml of the glucose oxidase solution is applied to a Sepharose 4 B column. The column is eluted with 5×10 -3 molar succinic acid buffer and 5×10 -3 molar EDTA, at about pH 5. The material effluent from the column is represented in Table II. The identical procedure may be performed with glucoamylase, amylase, or cellulase, with substantially identical results being produced.
EXAMPLE 2
Thirty ml of a solution of glucose oxidase (Miles-Servac, Aspergillus niger) is placed in a clean dry beaker. Enough solid sodium periodate (reagent grade) is added to the 30 ml of glucose oxidase solution to bring the concentration of the periodate to 0.1 molar. The solution is stirred for approximately 2 hours at about 0° C. The reaction is quenched with the addition of 15 ml of ethylene glycol, and 5 ml of the solution is applied to a Sepharose 4B column. The column is eluted with 5×10 -3 molar succinic acid buffer and 5×10 -3 molar EDTA, at about pH 5. The material eluted from the column produced the results shown in Table III.
In accordance with the provisions of the patent statutes the principles and mode of operation of the invention has been illustrated and described in what is considered to be its best embodiments. It is understood that, within the scope of the appended claims, the invention may be practiced otherwise than specifically illustrated, and described in the typical embodiments and accompanying alternatives herein.
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This invention relates to a method for purifying a carbohydrate containing enzyme which is a desired enzyme preferred to be separated from a mixture. The method comprises the steps of mixing a solution containing the carbohydrate containing enzyme with a carbohydrate modifying reagent. The carbohydrate modifying reagent reacts with the carbohydrate attached to the enzyme, thereby modifying its chemical structure. The modified enzyme is then separated from the other undesirable enzymes or proteins in the mixture by a suitable chemical separation method, for example, gel filtration chromatography. The method was used in the separation of glucose oxidase from catalase, a separation which by previous methods was very inefficient.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a division of co-pending application Ser. No. 185,090, filed Sept. 8, 1980, which in turn is a division of application Ser. No. 039,539, filed May 16, 1979, and now U.S. Pat. No. 4,244,951.
BACKGROUND OF THE INVENTION
This invention relates to new chemical compounds. More particularly it relates to new chemical compounds which are of value as antibacterial agents. These new antibacterial agents are bis-esters of methanediol, in which one hydroxy group of the methanediol has been esterified with the carboxy group of a 6-acylaminopenicillanic acid compound, and the other hydroxy group of the methanediol has been esterified with the carboxy group of penicillanic acid 1,1-dioxide.
In addition, this invention relates to the 6'-aminopenicillanoyloxymethyl ester, halomethyl esters, alkylsulfonyloxymethyl esters and arylsulfonyloxymethyl esters of penicillanic acid 1,1-dioxide. The latter compounds are useful intermediates to the antibacterial agents of this invention.
West German Offenlegungsschrift No. 2,824,535, published Dec. 14, 1978, and Iranian Patent No. 19,601, granted July 12, 1978, disclose penicillanic acid 1,1-dioxide, and esters thereof readily hydrolyzable in vivo, as antibacterial agents and as beta-lactamase inhibitors. Penicillanic acid 1,1-dioxide and esters thereof readily hydrolyzable in vivo increase the antibacterial effectiveness of certain penicillin and cephalosporin compounds against certain bacteria.
Belgian Patent No. 764,688, granted Mar. 23, 1971, discloses: (a) certain 6'-acylaminopenicillanoyloxymethyl 6-acylaminopenicillanates; (b) certain 6'-acylaminopenicillanoyloxymethyl 6-aminopenicillanates; (c) 6'-aminopenicillanoyloxymethyl 6-aminopenicillanate; and (d) chloromethyl 6-aminopenicillanate. U.S. Pat. No. 3,850,908 discloses chloromethyl esters of several natural, biosynthetic and semi-synthetic penicillin compounds.
The antibacterial agents of the present invention are efficiently absorbed from the gastrointestinal tract of mammals, and after absorption they are transformed into a 6-acylaminopenicillanic acid and penicillanic acid 1,1-dioxide.
SUMMARY OF THE INVENTION
This invention provides new antibacterial agents of the formula ##STR1## and the pharmaceutically-acceptable salts thereof, wherein R 1 is an acyl group of an organic carboxylic acid. However, preferred compounds of the formula I are those in which R 1 is an acyl group known from a natural, biosynthetic or semisynthetic penicillin compound. Especially preferred compounds of the formula I are those in which R 1 is selected from the group consisting of 2-phenylacetyl, 2-phenoxyacetyl, 2-amino-2-phenylacetyl, 2-amino-2-[4-hydroxyphenyl]acetyl, 2-carboxy-2-phenylacetyl, 2-carboxy-2-[2-thienyl]acetyl, 2-carboxy-2-[3-thienyl]acetyl, 2-[4-ethyl-2,3-dioxopiperazinocarbonylamino]-2-phenylacetyl and a group of the formula ##STR2## wherein R 3 is selected from the group consisting of hydrogen, alkanoyl having from two to four carbons and alkylsulfonyl having from one to three carbons.
Preferred individual compounds of formula I are:
6'-(2-phenylacetamido)penicillanoyloxymethyl penicillanate, 1,1-dioxide,
6'-(2-phenoxyacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide,
6'-(2-amino-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide and
6-(2-amino-2-[4-hydroxyphenyl]acetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide.
This invention also provides compounds of the formula: ##STR3## and the salts thereof, wherein X is a good leaving group. Examples of X are chloro, bromo, iodo, alkylsulfonyloxy having from one to four carbon atoms, benzenesulfonyloxy and toluenesulfonyloxy. The compounds of formulae III and IV are useful as intermediates to the antibacterial agents of the invention.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to derivatives of penicillanic acid, which is represented by the following structural formula ##STR4## In formula V, broken line attachment of a substituent to the bicyclic nucleus indicates that the substituent is below the plane of the bicyclic nucleus. Such a substituent is said to be in the alpha-configuration. Conversely, solid line attachment of a substituent to the bicyclic nucleus indicates that the substituent is attached above the plane of the nucleus. This latter configuration is referred to as the beta-configuration.
Using this system, the compounds of formulae I and III are named as derivatives of penicillanoyloxymethyl penicillanate (VA), in which primed and unprimed locants are used to distinguish between the two ring systems, viz: ##STR5##
Additionally, throughout this specification, whenever reference is made to a compound which has a 2-amino-2-(substituted)acetamido or 2-(substituted amino)-2-(substituted)acetamido group at the 6-position of a penicillanic acid derivative, it is to be understood that this refers to a compound in which said 2-amino-2-(substituted)acetamido or 2-(substituted amino)-2-(substituted)acetamido has the D-configuration.
In one method according to the invention a compound of formula I can be prepared by reacting a carboxylate salt of the formula ##STR6## with a compound of the formula ##STR7## wherein R 1 and X are as previously defined; and M is a carboxylate salt forming cation. A variety of cations can be used to form the carboxylate salt in the compound of formula VI, but salts which are commonly used include: alkali metal salts, such as sodium and potassium salts; alkaline earth metal salts, such as calcium and barium salts; and tertiary amine salts, such as trimethylamine, triethylamine, tributylamine, diisopropylethylamine, N-methylmorpholine, N-methylpiperidine, N-methylpyrrolidine, N,N'-dimethylpiperazine and 1,2,3,4-tetrahydroquinoline.
The reaction between a compound of formula VI and a compound of formula VII is usually carried out by contacting the reagents in a polar, organic solvent, at a temperature in the range from about 0° to about 80° C., and preferably from 25° to 50° C. The compounds of formula VI and VII are usually contacted in substantially equimolar proportions, but an excess of either reagent, for example up to a ten-fold excess, can be used. A wide variety of solvents can be used, but it is usually advantageous to use a relatively polar solvent, since this has the effect of speeding up the reaction. Typical solvents which can be used include N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide and hexamethylphosphoramide. The reaction time varies according to a number of factors, but at about 25° C. reaction times of several hours, e.g. 12 to 24 hours, are commonly used. When X is chloro or bromo, it is sometimes advantageous to add up to about one molar equivalent of an alkali metal iodide, which has the effect of speeding up the reaction.
The compound of formula I is isolated in conventional fashion. When a water-miscible solvent is used, it is usually sufficient simply to dilute the reaction medium with an excess of water. The product is then extracted into a water immiscible solvent, such as ethyl acetate, and then the product is recovered by solvent evaporation. When a water immiscible solvent is used, it is usually sufficient to wash the solvent with water, and then recover the product by solvent evaporation. The compound of formula I can be purified by well-known methods, such as recrystallization or chromatography, but due regard must be given to the lability of the beta-lactam ring system.
When the group R 1 in a compound of formula VI contains a basic group, such as a primary amino group, this group can interfere during the reaction with the ester VII. In this case it is usually advantageous to protect the amino group in R 1 before contacting the compound of formula VI with the compound of formula VII. A variety of conventional amino protecting groups can be used for this purpose. The only requirements for such a group are that: (a) it can be affixed to the compound of formula VI under conditions which do not adversely affect the compound of formula VI; (b) it is stable under the conditions under which the compound of formula VI reacts with the compound of formula VII; and (c) it can be removed after the reaction with the compound of formula VII is complete, using conditions which do not adversely affect the compound of formula I. Typical amino protecting groups which can be used are benzyloxycarbonyl, substituted benzyloxycarbonyl, 2-nitrophenylsulfenyl and 2,2,2-trichloroethoxycarbonyl. Benzyloxycarbonyl and 4-nitrobenzyloxycarbonyl are particularly convenient groups.
When the group R 1 in a compound of formula VI contains a carboxy group, it is usual to protect this carboxy group before the reaction with the compound of formula VII, particularly when the carboxy group is subject to ready decarboxylation. In this case it is advantageous to start with a compound of formula VI in which the carboxy group in R 1 is in the form of a readily hydrolyzable ester, e.g. a phenyl or substituted phenyl ester. After the coupling with the compound of formula VII is complete, the free carboxy group in R 1 is liberated by mild, alkaline hydrolysis, e.g. using the technique disclosed in U.S. Pat. No. 3,679,801. This methodology is especially useful when R 1 is a group such as 2-carboxy-2-phenylacetyl, 2-carboxy-2-[thienyl]acetyl, etc.
A variation of the foregoing method of preparing a compound of formula I involves reaction of a compound of the formula ##STR8## with a compound of the formula ##STR9## wherein M and X are as defined previously, and R 2 is the group R 1 , but with any free amino groups and/or carboxy groups protected, followed if necessary by removal of any amino or carboxy protecting group. In the compounds of formula IX, the free amino groups and the carboxy groups are protected with exactly the same protecting groups as described earlier for the compound of formula VI. The reaction between a compound of formula VIII and IX is carried out in exactly the same manner that is used for the reaction of a compound of formula VI with a compound of formula VII. Finally, any amino and/or carboxy protecting groups are removed, and these are removed in conventional manner for the group involved.
In another method according to the invention, a compound of formula I can be prepared by acylation of the compound of formula III with an activated derivative of an acid of the formula R 2 --COOH, wherein R 2 is as previously defined, followed if necessary by removal of any amino and/or carboxy protecting groups from R 2 . This converts the moiety R 2 --CO into the moiety R 1 --CO.
The acylation reaction is usually conducted in a reaction-inert solvent system. In a typical acylation procedure, from about 0.5 to about three molar equivalents of the activated derivative of the acid of formula R 2 --COOH is contacted with the compound of formula III, in a reaction-inert solvent system, at a temperature in the range from about -40° to about 30° C., and preferably from about -10° to about 10° C. The preferred ratio of activated derivative to compound of formula III is 1.0:1.0 to 1.2:1.0. Reaction-inert solvents which are commonly used in this acylation are: chlorinated hydrocarbons, such as chloroform and dichloromethane; ethers, such as diethyl ether and tetrahydrofuran; low molecular weight esters, such as ethyl acetate and butyl acetate; low molecular weight aliphatic ketones, such as acetone and methyl ethyl ketone; tertiary amides, such as N,N-dimethylformamide and N-methylpyrrolidone; acetonitrile; water; and mixtures thereof. When aqueous or partially aqueous solvent systems are used, the pH should be maintained in the range from about 4 to about 9, and preferably about 7.
An activated derivative of the acid of the formula R 2 --COOH which is commonly used is an acid halide, e.g. the acid chloride. In this instance it is preferable, though not essential, to carry out the acylation in the presence of an acid binder. Suitable acid binders are tertiary amines such as trialkylamines, e.g. triethylamine, N-methylmorpholine, N,N-dimethylaniline, pyridine and the like, or bicarbonates such as potassium bicarbonate or sodium bicarbonate. Buffer systems such as phosphate buffers can also be used.
Other activated derivatives of the acid of formula R 2 --COOH which can be used are active esters. Examples of active esters are phenyl esters, such as 4-nitrophenyl and 2,4,5-trichlorophenyl esters; thio esters, such as thiol methyl and thiol phenyl esters; and N-hydroxy esters, such as N-hydroxysuccinimide and N-hydroxyphthalimide esters. These active esters are prepared by methods well-known in the art. In many cases, the active ester can be replaced by the corresponding acid azide, or by the imidazole or triazole amide.
Another method for activation of the acid of formula R 2 --COOH involves mixed anhydride formation, i.e. mixed carboxylic-carbonic and mixed dicarboxylic anhydride formation. In the case of mixed carboxylic carbonic anhydrides, a carboxylate salt of the acid of formula R 2 --COOH is usually reacted with a lower-alkyl chloroformate, e.g. ethyl chloroformate; in the case of a mixed dicarboxylic anhydride, a carboxylate salt of the acid of formula R 2 --COOH is usually reacted with a hindered lower-alkanoyl chloride, e.g. pivaloyl chloride.
In addition to the above, the acid of formula R 2 --COOH can be activated by contacting the acid with a peptide coupling agent, according to standard procedures. Such agents include carbodiimides, for example dicyclohexylcarbodiimide, alkoxyacetylenes, for example methoxyacetylene and ethoxyacetylene, and N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline.
The protecting groups used to protect amino or carboxy groups in a compound of formula R 2 --COOH are those conventionally used during acylation of a 6-aminopenicillanic acid derivative. Protecting groups which are particularly useful for amino groups are the benzyloxycarbonyl group, the 4-nitrobenzyloxycarbonyl group and the enamines formed by condensation with a beta-dicarbonyl compound such as an alkyl acetoacetate. After the acylation step, the amino protecting group is removed in conventional fashion. When the acid of formula R 2 --COOH is to be activated as an acid halide e.g. acid chloride, an especially convenient manner of protecting an amino group involves salt formation, e.g. formation of a hydrochloride salt.
The compounds of formula VI are known antibiotics, which are prepared by the published procedures.
The compounds of formula VII are prepared from the compounds of formula VIII by reaction with a compound of formula Y--CH 2 --X, wherein X and Y are each good leaving groups, e.g. chloro, bromo, iodo, alkylsulfonyloxy, benenesulfonyloxy or toluenesulfonyloxy. The same conditions that were described previously for reaction of a compound of formula VII with a compound of formula VI are used for this reaction, except that it is preferable to use an excess of the compound of formula X--CH 2 --Y (e.g. a four-fold excess).
In like manner, the compounds of formula IX are prepared by reaction of a compound of formula ##STR10## with a compound of formula Y--CH 2 --X, wherein R 2 , M, Y and X are as previously defined. The conditions used are the same as those described previously for reaction of a compound of formula VIII with a compound of formula X--CH 2 --Y.
The compound of formula III can be prepared by a three-step procedure which comprises: (a) conversion of 6-aminopenicillanic acid into a 6-(protected amino)penicillanic acid; (b) reaction of a salt of the 6-(protected amino)penicillanic acid with a compound of formula VII; and (c) removal of the amino protecting group. A wide variety of amino protecting groups can be used for this purpose, and typical examples are benzyloxycarbonyl, 4-nitrobenzyloxycarbonyl and 2,2,2-trichloroethoxycarbonyl. Steps (a) and (c) are carried out in conventional fashion, and step (b) is carried out in exactly the same manner that was described previously for reaction of a compound of formula VII with a compound of formula VI.
Alternatively, the compound of formula III can be prepared by a four-step procedure which comprises (i) conversion of 6-aminopenicillanic acid into a 6-(protected amino)penicillanic acid; (ii) reaction of a salt of the 6-(protected amino)penicillanic acid with a compound of formula X--CH 2 --Y, wherein X and Y are as previously defined; (iii) reaction of the product of step (ii) with a compound of formula VIII; and (iv) removal of the amino protecting group. A wide variety of amino protecting groups can be used for this purpose, and typical examples are benzyloxycarbonyl, 4-nitrobenzyloxycarbonyl and 2,2,2-trichloroethoxycarbonyl. Steps (i) and (iv) are carried out in conventional fashion; step (ii) is carried out in exactly the same manner that was described previously for reaction of a compound of formula VIII with a compound of formula X--CH 2 --Y; and step (iii) is carried out in exactly the same manner that was described previously for reaction of a compound of formula VI with a compound of formula VII.
Penicillanic acid 1,1-dioxide and the salts thereof are prepared by published procedures (see West German Offenlegungsschrift No. 2,824,535).
Those compounds of formula I which have a basic function, e.g. an amino group, in the group R 1 will form acid addition salts, and these acid addition salts are considered to be within the scope and purview of this invention. Said acid addition salts are prepared by standard methods for penicillin compounds, for example by combining a solution of the compound of formula I in a suitable solvent (e.g. water, acetone, methanol, ethanol or butanol) with a solution containing a stoichiometric equivalent of the appropriate acid. If the salt precipitates, it is recovered by filtration. Alternatively, it can be recovered by evaporation of the solvent, or, in the case of aqueous solutions, by lyophilization. Of particular value are the sulfate, hydrochloride, hydrobromide, nitrate, phosphate, citrate, tartrate, pamoate, perchlorate, sulfosalicylate and 4-toluenesulfonate salts.
Those compounds of formula I which have an acidic function, e.g. a carboxyl group, in the group R 1 will form base salts, and these base salts are to be considered within the scope and purview of this invention. The base salts are prepared by standard methods for penicillin compounds, for example by contacting the acidic and basic components in a stoichiometric ratio, in an aqueous, non-aqueous or partially aqueous medium, as appropriate. they are then recovered by filtration, by precipitation with a non-solvent followed by filtration, by evaporation of the solvent, or, in the case of aqueous solutions, by lyophilization, as appropriate. Basic agents which are suitably employed in salt formation belong to both the organic and inorganic types, and they include ammonia, organic amines, alkaline metal hydroxides, carbonates, bicarbonates, hydrides and alkoxides, as well as alkaline earth metal hydroxides, carbonates, hydrides and alkoxides. Representative examples of such bases are primary amines, such as n-propylamine, n-butylamine, aniline, cyclohexylamine, benzylamine, p-toluidine and octylamine; secondary amines, such as diethylamine, N-methylaniline, morpholine, pyrrolidine and piperidine; tertiary amines, such as triethylamine, N,N-dimethylaniline, N-ethylpiperidine, N-methylmorpholine and 1,5-diazabicyclo[4.3.0]non-5-ene; hydroxides, such as sodium hydroxide, potassium hydroxide, ammonium hydroxide and barium hydroxide; alkoxides, such as sodium ethoxide and potassium ethoxide; hydrides, such as calcium hydride and sodium hydride; carbonates, such as potassium carbonate and sodium carbonate; and bicarbonates, such as sodium bicarbonate and potassium bicarbonate.
When contemplating therapeutic use for a salt of an antibacterial compound of this invention, it is necessary to use a pharmaceutically-acceptable salt; however, salts other than these can be used for a variety of purposes. Such purposes include isolating and purifying particular compounds, and interconverting pharmaceutically-acceptable salts and their non-salt counterparts.
The compounds of formula I possess in vivo antibacterial activity in mammals, and this activity can be demonstrated by standard techniques for penicillin compounds. For example, the compound of formula I is administered to mice in which acute infections have been established by intraperitoneal inoculation with a standardized culture of a pathogenic bacterium. Infection severity is standardized such that the mice receive one to ten times the LD 100 (LD 100 : the minimum inoculation required to consistently kill 100 percent of control mice). At the end of the test, the activity of the compound is assessed by counting the number of survivors which have been challenged by the bacterium and also have received the compound of formula I. The compounds of formula I can be administered by both the oral (p.o.) and subcutaneous (s.c.) route.
The in vitro activity of the antibacterial compounds of this invention makes them suitable for the control of bacterial infections in mammals, including man, by both the oral and parenteral modes of administration. The compounds are useful in the control of infections caused by susceptible bacteria in human subjects. In general, it is the substituent R 1 which determines whether a given bacterium will be susceptible to a given compound of formula I. A compound of formula I breaks down to the corresponding compound of formula VI (or free acid thereof) and penicillanic acid 1,1-dioxide after administration to a mammalian subject by both the oral and parenteral route. Penicillanic acid 1,1-dioxide then functions as a beta-lactamase inhibitor, and it increases the antibacterial effectiveness of the compound of formula VI (or free acid thereof). For example, when R 1 is 2-phenylacetyl or 2-phenoxyacetyl, the compounds will find use in the control of infections caused by susceptible strains of Straphylococcus aureus; when R 1 is D-2-amino-2-phenylacetyl, D-2-amino-2-[4-hydroxyphenyl]acetyl, 2-carboxy-2-phenylacetyl, 3-carboxy-2 -[2-thienyl]acetyl, 2-carboxy-2-[3-thienyl]acetyl, 2-[4-ethyl-2,3-dioxopiperazinocarbonylamino]-2-phenylacetyl or a group of formula II, the compounds are useful in the control of infections caused by susceptible strains of Escherichia coli.
In determining whether a particular strain of Staphylococcus aureus or Escherichia coli is sensitive to a particular compound of formula I, the in vivo test described earlier can be used. Alternatively, the minimum inhibitory concentration (MIC) of a 1:1 mixture of the compound of formula VI (or its corresponding free acid) and the compound of formula VIII (or its corresponding free acid) can be measured. The MIC's can be measured by the procedure recommended by the International Collaborative Study on Antibiotic Sensitivity Testing (Ericcson and Sherris, Acta. Pathologica et Microbiologia Scandinav, Supp. 217, Section B: 64-68 [1971]), which employs brain heart infusion (BHI) agar and the inocula replicating device. Overnight growth tubes are diluted 100 fold for use as the standard inoculum (20,000-10,000 cells in approximately 0.002 ml. are placed on the agar surface; 20 ml. of BHI agar/dish). Twelve 2 fold dilutions of the test compound are employed, with initial concentration of the test drug being 200 mcg./ml. Single colonies are disregarded when reading plates after 18 hrs. at 37° C. The susceptibility (MIC) of the test organism is accepted as the lowest concentration of compound capable of producing complete inhibition of growth as judged by the naked eye.
When using an antibacterial compound of this invention, or a salt thereof, in a mammal, particularly man, the compound can be administered alone, or it can be mixed with other antibiotic substances and/or pharmaceutically-acceptable carriers or diluents. Said carrier or diluent is chosen on the basis of the intended mode of administration. For example, when considering the oral mode of administration, an antibacterial compound of this invention can be used in the form of tablets, capsules, lozenges, troches, powders, syrups, elixirs, aqueous solutions and suspensions, and the like, in accordance with standard pharmaceutical practice. The proportional ratio of active ingredient to carrier will naturally depend on the chemical nature, solubility and stability of the active ingredient, as well as the dosage contemplated. In the case of tablets for oral use, carriers which are commonly used include lactose, sodium citrate and salts of phosphoric acid. Various disintegrants such as starch, and lubricating agents, such as magnesium stearate, sodium lauryl sulfate and talc, are commonly used in tablets. For oral administration in capsule form, useful diluents are lactose and high molecular weight polyethylene glycols, e.g. polyethylene glycols having molecular weights of from 2000 to 4000. When aqueous suspensions are required for oral use, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening and/or flavoring agents can be added. For parenteral administration, which includes intramuscular, intraperitoneal, subcutaneous, and intravenous use, sterile solutions of the active ingredient are usually prepared, and the pH of the solutions are suitably adjusted and buffered. For intravenous use, the total concentration of solutes should be controlled to render the preparation isotonic.
As indicated earlier, the antibacterial compounds of this invention are of use in human subjects and the daily dosages to be used will not differ significantly from other, clinically-used, penicillin antibiotics. The prescribing physician will ultimately determine the appropriate dose for a given human subject, and this can be expected to vary according to the age, weight, and response of the individual patient as well as the nature and the severity of the patient's symptoms. The compounds of this invention will normally be used orally at dosages in the range from about 20 to about 100 mg. per kilogram of body weight per day, and parenterally at dosages from about 10 to about 100 mg. per kilogram of body weight per day, usually in divided doses. In some instances it may be necessary to use doses outside these ranges.
The following examples and preparations are provided solely for further illustration. Infrared (IR) spectra were measured as potassium bromide discs (KBr discs) and diagnostic absorption bands are reported in wave numbers (cm -1 ). Nuclear magnetic resonance spectra (NMR) were measured at 60 MHz for solutions in deuterated chloroform (CDCl 3 ) or deuterated dimethyl sulfoxide (DMSO-d 6 ), and peak positions are reported in parts per million downfield from tetramethylsilane. The following abbreviations for peak shapes are used: s, singlet; d, doublet; t, triplet; q, quartet, m, multiplet.
EXAMPLE 1
6'-(2-Phenylacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
To a stirred solution of 1.3 g. of potassium 6-(2-phenylacetamido)penicillanate in 20 ml. of dimethyl sulfoxide was added 845 mg. of chloromethyl penicillanate 1,1-dioxide followed by a few milligrams of sodium iodide. Stirring was continued overnight at ca. 25° C., and then the reaction mixture was poured into 140 ml. of ice-water. The pH was raised to 8.5, and then the mixture was extracted with ethyl acetate. The combined ethyl acetate extracts were washed with water, dried (Na 2 SO 4 ) and evaporated in vacuo. This afforded 600 mg. of crude material.
The crude material was chromatographed on silica gel, eluting with a 1:1 mixture of ethyl acetate and hexane, and this afforded 200 mg. of the title compound (12% yield). The IR spectrum (KBr disc) showed an absorption at 1783 cm -1 . The NMR spectrum (CDCl 3 ) showed absorptions at 7.4 (s), 6.3 (d), 5.9 (s), 5.8-5.3 (m), 4.65 (t), 4.45 (s), 3.65 (s), 3.45 (d), 1.62 (s) and 1.48-1.4 (m) ppm.
EXAMPLE 2
6'-(2-Phenoxyacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
A mixture of 1.4 g. of potassium 6-(2-phenoxyacetamido)penicillanate, 845 mg. of chloromethyl penicillanate 1,1-dioxide, 20 ml. of dimethyl sulfoxide and a few milligrams of sodium iodide was stirred at ca. 25° C. overnight. The mixture was poured into 140 ml. of ice-water and the pH was adjusted to 8.5. The resultant aqueous system was extracted with ethyl acetate, and the extracts were combined, washed with water, dried (Na 2 SO 4 ) and evaporated in vacuo. This afforded 660 mg. of crude material.
The crude material was chromatographed on silica gel, using a 1:1 mixture of ethyl acetate and hexane as eluant, and this afforded 230 mg. of the title product (13% yield). The IR spectrum (KBr disc) showed an absorption at 1786 cm -1 . The NMR spectrum (CDCl 3 ) showed absorptions at 7.4 (s), 5.85 (s), 5.45 (s), 5.05 (s), 4.6 (t), 4.43 (s), 4.4 (s), 3.45 (d), 1.62 (s), 1.48 (s), 1.44 (s) and 1.4 (s) ppm.
EXAMPLE 3
6'-(2-Amino-2-phenylacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
To a solution of 1.6 g. of 6'-(2-benzyloxycarbonylamino-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide in 100 ml. of tetrahydrofuran and 80 ml. of water was added 0.12 ml. of glacial acetic acid followed by 1.6 g. of 10% palladium-on-carbon. The mixture was shaken under an atmosphere of hydrogen at a pressure of ca. 50 psig for 1.5 hours. At this point the catalyst was removed by filtration and 1.6 g. of fresh catalyst was added. The mixture was shaken under hydrogen at ca. 50 psig for a further 1 hour. The catalyst was removed by filtration and the bulk of the tetrahydrofuran was removed by evaporation in vacuo. The pH of the residual aqueous phase was lowered to 2.0 using 6 N hydrochloric acid and the acidified solution was extracted with ethyl acetate. The extracts were dried (Na 2 SO 4 ) and evaporated in vacuo to give 500 mg. of impure starting material. The pH of the above acidified solution was raised to 8.5 and then it was further extracted with ethyl acetate. The latter extracts were combined, dried (Na 2 SO 4 ) and evaporated in vacuo to give 500 mg. of the title compound (38% yield).
EXAMPLE 4
6'-(2-Benzyloxycarbonylamino-2-phenylacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
To a stirred solution of 1.9 g. of potassium 6-(2-benzyloxycarbonylamino-2-phenylacetamido)penicillanate in 30 ml. of dimethyl sulfoxide was added 930 mg. of chloromethyl penicillanate 1,1-dioxide followed by a few milligrams of sodium iodide. Stirring was continued at ambient temperature overnight, and then the reaction mixture was poured into 60 ml. of water. The pH was raised to 8.5 and the product was extracted into ethyl acetate. The extracts were washed with water and with saturated sodium chloride solution, and then they were dried (Na 2 SO 4 ). Evaporation of the ethyl acetate in vacuo gave 800 mg. of crude product.
The crude product was purified by chromatography on silica gel, using 1:1 ethyl acetate-hexane as eluant, to give 440 mg. of the title compound (18% yield). The NMR spectrum of the product (CDCl 3 ) showed absorptions at 7.4 (m, 10H), 7.1 (d, 1H, J=8 Hz), 6.2 (d, 1H, J=8 Hz), 5.9 (s, 2H), 5.7-5.2 (m, 3H), 5.1 (s, 2H), 4.6 (t, 1H), 4.4 (s, 2H), 3.4 (d, 2H) and 1.7-1.2 (m, 12H) ppm.
EXAMPLE 5
6'-(2-Amino-2-phenylacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
6'-(2-[4-Nitrobenzyloxycarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate, 1,1-dioxide was hydrogenated in the presence of 10% palladium-on-carbon, according to the procedure of Example 3. After the hydrogenation, the catalyst was removed by filtration and the pH was raised to 8.5. The resulting mixture was extracted with ethyl acetate, and then the extracts were combined, dried using sodium sulfate and evaporated in vacuo. The residue was dissolved in 3 ml. of ethyl acetate, and the resulting solution was added dropwise to 40 ml. of hexane. The solid which precipitated was recovered by filtration to give 500 mg. of crude product.
The crude product was purified by chromatography on silica gel, using ethyl acetate as eluant, to give a 40% yield of the title compound. The IR spectrum (KBr disc) showed an absorption at 1802 cm -1 . The NMR spectrum (CDCl 3 ) showed absorptions at 8.1 (d, 1H, J=6 Hz), 7.4 (s, 4H), 5.9 (q, 2H), 5.7-5.5 (m, 2H), 4.75-4.6 (m, 2H), 4.55 (s, 1H), 4.45 (s, 1H), 3.55 (d, 2H), 1.6 (d, 6H) and 1.5 (d, 6H) ppm.
EXAMPLE 6
6'-(2-[4-Nitrobenzyloxycarbonylamino]-2-phenylacetamido)-penicillanoyloxymethyl Penicillanate 1,1-Dioxide
The title compound was prepared from potassium 6-(2-[4-nitrobenzyloxycarbonylamino]-2-phenylacetamido)penicillanate and chloromethyl penicillanate 1,1-dioxide using the procedure of Example 4, except that the reaction mixture was heated at 45° C. for 3 hours after being allowed to stir overnight at ambient temperature. After chromatography on silica gel, a 24% yield of product was obtained. The NMR spectrum (CDCl 3 ) showed absorptions at 8.2 (d, 2H, J=8 Hz), 7.7-7.4 (m, 7H), 6.9 (d, 2H, J=8 Hz), 5.9 (s, 2H), 5.8-5.3 (m, 3H), 5.2 (s, 2H), 4.7 (t, 1H), 4.5 (s, 2H), 3.5 (d, 2H) and 1.7-1.4 (m, 12H) ppm.
EXAMPLE 7
6'-(2-Amino-2-[4-Hydroxyphenyl]acetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
To a solution of 700 mg. of 6'-(2-[4-nitrobenzyloxycarbonylamino]-2-[4-hydroxyphenyl]acetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide in 25 ml. of water and 35 ml. of tetrahydrofuran was added 700 mg. of 10% palladium-on-carbon. This mixture was shaken under an atmosphere of hydrogen at ca. 50 psig for 70 minutes. The catalyst was removed by filtration and then the bulk of the tetrahydrofuran was removed by evaporation in vacuo. The remaining aqueous phase was basified to pH 8.5, and then it was extracted with ethyl acetate. The extracts were washed with water and with saturated sodium chloride solution, and then they were dried (Na 2 SO 4 ) and evaporated in vacuo. The residue was dissolved in 3 ml. of ethyl acetate, and this solution was added dropwise to an excess of hexane. The solid which precipitated was recovered by filtration and dried to give 300 mg. of the title compound (56% yield).
The above product was combined with additional material of similar purity and chromatographed on silica gel using ethyl acetate as the eluant. The appropriate column fractions were combined and evaporated in vacuo, and the residue was dissolved in a small volume of ethyl acetate. The latter solution was then added dropwise to an excess of hexane, and the solid which precipitated was recovered by filtration. The IR spectrum (KBr disc) of the material so obtained showed an absorption at 1786 cm -1 . The NMR spectrum (CDCl 3 /DMSO-d 6 ) showed absorptions at 7.4-6.6 (m, 4H), 5.9 (s, 1H), 5.8-5.4 (m, 2H), 4.8-4.3 (m, 4H), 3.5 (d, 2H) and 1.5 (m, 12H) ppm.
EXAMPLE 8
6'-(2-[4-Nitrobenzyloxycarbonylamino]-2-[4-hydroxyphenyl]acetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
A solution of 7.0 g. of potassium 6-(2-[4-nitrobenzyloxycarbonylamino]-2-[4-hydroxyphenyl]acetamido)penicillanate and 3.0 g. of chloromethyl penicillanate 1,1-dioxide in 40 ml. of dimethyl sulfoxide was heated at 45° C. for 4.5 hours. The solution was the poured into 120 ml. of water and the pH was adjusted to 8.5. The resulting mixture was extracted with ethyl acetate, and the combined extracts were washed with water and with saturated sodium chloride solution and then they were dried (Na 2 SO 4 ). The dried solution was evaporated in vacuo to give 2.0 g. of crude product.
The crude product was purified by chromatography on silica gel using 1.5:1 ethyl acetate-hexane as eluant. This afforded 720 mg. (9% yield) of material which showed only a single spot when assayed by thin-layer chromatography.
EXAMPLE 9
The procedure of Example 1 is repeated, except that the potassium 6-(2-phenylacetamido)penicillanate is replaced by:
potassium 6-(2-[4-ethyl-2,3-dioxopiperazinocarbonylamino]-2-phenylacetamido)penicillanate,
potassium 6-(2-[2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanate,
potassium 6-(2-[3-acetyl-2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanate,
potassium 6-(2-[3-butyryl-2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanate,
potassium 6-(2-[3-methylsulfonyl-2-oximidazolidinocarbonylamino]-2-phenylacetamido)penicillanate and
potassium 6-(2-[3-isopropylsulfonyl-2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanate, respectively. This affords:
6'-(2-[4-ethyl-2,3-dioxopiperazinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide,
6'-(2-[2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide,
6'-(2-[3-acetyl-2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide,
6'-(2-[3-butyryl-2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide,
6'-(2-[3-methylsulfonyl-2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide and
6'-(2-[3-isopropylsulfonyl-2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide, respectively.
EXAMPLE 10
The procedure of Example 2 is repeated, except that the chloromethyl penicillanate 1,1-dioxide used therein is replaced by an equimolar amount of:
bromomethyl penicillanate 1,1-dioxide,
iodomethyl penicillanate 1,1-dioxide,
methylsulfonyloxymethyl penicillanate, 1,1-dioxide,
isobutylsulfonyloxymethyl penicillanate 1,1-dioxide,
benzenesulfonyloxymethyl penicillanate 1,1-dioxide and
4-toluenesulfonyloxymethyl penicillanate 1,1-dioxide, respectively. In each case, this affords 6'-(2-phenoxyacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide.
EXAMPLE 11
6'-(2-Benzyloxycarbonylamino-2-phenylacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
A mixture of 570 mg. of chloromethyl 6-(2-benzyloxycarbonylamino-2-phenylacetamido)penicillanate, 324 mg. of sodium penicillanate 1,1-dioxide, a few milligrams of sodium iodide and 20 ml. of dimethyl sulfoxide was stirred at room temperature overnight. The reaction mixture was added to 80 ml. of water, and the pH was raised to 8.5. The product was extracted into ethyl acetate. The extract was washed with water and with saturated sodium chloride solution, and then it was dried (Na 2 SO 4 ). Evaporation in vacuo then afforded 360 mg. of the title compound.
EXAMPLE 12
6'-(2-[4-Nitrobenzyloxycarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
A mixture of 500 mg. of chloromethyl 6-(2-[4-nitrobenzyloxycarbonylamino]-2-phenylacetamido)penicillanate, 245 mg. of sodium penicillanate 1,1-dioxide, a few milligrams of sodium iodide and 10 ml. of dimethyl sulfoxide was stirred at room temperature overnight. At this point, an additional 83 mg. of sodium penicillanate 1,1-dioxide was added. Stirring was continued for 4 hours, and then the reaction mixture was poured into water. The aqueous system was basified to pH 8.5, and then it was extracted with ethyl acetate. The extracts were combined, washed with water and with saturated sodium chloride solution, and then they were dried (Na 2 SO 4 ). Evaporation in vacuo then afforded 430 mg. of the title compound, contaminated with some chloromethyl 6-(2-[4-nitrobenzyloxycarbonylamino]-2-phenylacetamido)penicillanate.
EXAMPLE 13
6'-(2-[4-Nitrobenzyloxycarbonylamino]-2-[4-hydroxyphenyl]-acetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
A solution of 2.07 g. of chloromethyl 6-(2-[4-nitrobenzyloxycarbonylamino]-2-[4-hydroxyphenyl]acetamido)penicillanate, 1.1 g. of sodium penicillanate 1,1-dioxide, and a few milligrams of sodium iodide in 30 ml. of dimethyl sulfoxide was maintained at 45° C. for 5 hours. The reaction mixture was added to 100 ml. of water and the pH was raised to 8.5. The product was extracted into ethyl acetate. The extracts were combined, washed with water and with saturated sodium chloride solution, and then they were dried (Na 2 SO 4 ). Evaporation in vacuo then afforded 1.6 g. of crude product.
The crude product was chromatographed on silica gel using 1.5:1 ethyl acetate-hexane as eluant, to give 550 mg. (18% yield) of the title compound. The NMR spectrum (CDCl 3 /DMSO-d 6 ) showed absorptions at 8.4 (d, 1H, J=8 Hz), 8.1 (d, 2H, J=8 Hz), 7.7-6.6 (m, 7H), 5.9 (s, 2H), 5.7-5.2 (m, 3H), 5.2 (s, 2H), 4.7 (t, 1H), 4.4 (d, 2H) and 1.5 (d, 12H) ppm.
EXAMPLE 14
Chloromethyl 6-(2-phenylacetamido)penicillanate and chloromethyl 6-(2-phenoxyacetamido)penicillanate are reacted with sodium penicillanate 1,1-dioxide, according to the procedure of Example 11. This affords:
6'-(2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide and
6'-(2-phenoxyacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide, respectively.
EXAMPLE 15
6'-(2-Phenylacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
To a stirred solution of 4.62 g. of 6'-aminopenicillanoyloxymethyl penicillanate 1,1-dioxide in 25 ml. of chloroform is added 1.50 ml. of triethylamine. The mixture is cooled to 0° C., and a solution of 1.55 g. of 2-phenylacetyl chloride in 10 ml. of chloroform is added dropwise at 0° C. The resulting mixture is stirred for 5 minutes at 0° C. and then for 30 minutes at 25° C. The solvent is removed by evaporation in vacuo and the residue is partitioned between ethyl acetate and water at pH 8. The ethyl acetate layer is removed, washed with water, dried (Na 2 SO 4 ) and evaporated in vacuo, to give the title compound.
EXAMPLE 16
6'-(2-Phenoxyacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
The title compound is prepared by acylation of 6'-aminopenicillanoyloxymethyl penicillanate 1,1-dioxide with 2-phenoxyacetyl chloride, according to the procedure of Example 15.
EXAMPLE 17
6'-(2-Amino-2-phenylacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
To a stirred solution of 155.2 g. of potassium N-(1-methyl-2-ethoxycarbonylvinyl)-D-2-amino-2-phenylacetate hemihydrate (Chem. Ber., 98, 789 [1965]) in 2,000 ml. of ethyl acetate is added 2.5 ml. of N-methylmorpholine and 70 ml. of isobutyl chloroformate, at -15° C. Stirring is continued at -15° C. for 15 minutes, an then a solution of 231 g. of 6'-aminopenicillanoyloxymethyl penicillanate 1,1-dioxide in 1,000 ml. of ethyl acetate is added, dropwise, at -15° C., over a period of 15 minutes. Stirring is continued at 15° C. for 1 hour and then the reaction mixture is allowed to warm to room temperature. At this point the reaction mixture is washed with water, aqueous sodium bicarbonate (0.5 M) and again with water. The ethyl acetate solution is then dried and evaporated in vacuo. The residue is dissolved in 2,000 ml. of 1:1 tetrahydrofuran-water and the pH is adjusted to 2.5. The solution is stirred at a pH of 2.5 for 1 hour, and then the bulk of the tetrahydrofuran is removed by evaporation in vacuo. The pH of the aqueous phase is adjusted to 8.5, and then the aqueous phase is extracted with ethyl acetate. The extracts are washed with water, dried (Na 2 SO 4 ) and evaporated in vacuo to give the title compound.
EXAMPLE 18
6'-(2-Amino-2-[4-hydroxyphenyl]acetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
The title compound is prepared from 6'-aminopenicillanoyloxymethyl penicillanate 1,1-dioxide and sodium N-(1-methyl-2-methoxycarbonylvinyl)-D-2-amino-2-(4-hydroxyphenyl)acetate (Journal of the Chemical Society [London] Part C, 1920 [1971]), using the procedure of Example 17.
EXAMPLE 19
6'-(2-Carboxy-2-phenylacetamido)penicillanoyloxymethyl Penicillanate, 1,1-Dioxide
To a stirred solution of 2.31 g. of 6'-aminopenicillanoyloxymethyl penicillanate 1,1-dioxide in 15 ml. of ethyl acetate is added 0.605 g. of N,N-dimethylaniline at 0° C. The temperature is maintained at 0° C., and 30 ml. of a 0.2 molar solution of phenylmalonyl chloride trimethylsilyl ester is added dropwise during 5 minutes. The reaction mixture is washed with water, and then an equal volume of fresh water is added. The pH of the aqueous phase is adjusted to 7.0 with saturated sodium bicarbonate and the layers are separated. The organic layer is discarded, and fresh ethyl acetate is added to the aqueous layer. The pH of the aqueous layer is lowered to 3.5, and again the layers are separated. The ethyl acetate layer is dried (Na 2 SO 4 ) and evaporated in vacuo to give the title compound.
The 0.2 molar solution of phenylmalonyl chloride trimethylsilyl ester is prepared according to Preparation A of U.S. Pat. No. 3,862,933.
EXAMPLE 20
6'-(2-Carboxy-2-[3-thienyl]acetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
The title compound is prepared by acylation of 6'-aminopenicillanoyloxymethyl penicillanate 1,1-dioxide with [3-thienyl]malonyl chloride trimethylsilyl ester, following the procedure of Example 19. [3-Thienyl]-malonyl chloride trimethylsilyl ester is prepared accordin to the method of U.S. Pat. No. 3,862,933.
EXAMPLE 21
6°-(2-Carboxy-2-[2-thienyl]acetamido)penicillanoyloxymethyl Penicillanate, 1,1-Dioxide
The pH of a stirred suspension of 372 mg. of 2-[2-thienyl]malonic acid in 10 ml. of water and 5 ml. of tetrahydrofuran is adjusted to 6.0 by the addition of saturated sodium bicarbonate solution. To the resulting solution is added 923 mg. of 6'-aminopenicillanoyloxymethyl penicillanate 1,1-dioxide. The mixture is cooled to ca. 0° C., and 402 mg. of N-ethyl-N'-3-(dimethylamino)propylcarbodiimide hydrochloride is added, with stirring. Stirring is continued at ca 0° C. for 5 minutes and at 25° C. for 2 hours, the pH continuously being maintained between 5.8 and 6.0. At this point, the bulk of the tetrahydrofuran is removed by evaporation in vacuo, ethyl acetate and additional water are added and the pH is raised to 8.0. The layers are separated and the organic layer is discarded. Fresh ethyl acetate is added, and the pH is lowered to 3.0. Again the layers are separated, and the ethyl acetate layer is dried (Na 2 SO 4 ) and evaporated in vacuo. This affords the title compound.
EXAMPLE 22
6'-(2-[4-Ethyl-2,3-dioxopiperazinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
To a stirred mixture of 3.19 g. of 2-(4-ethyl-2,3-dioxopiperazinocarbonylamino)-2-phenylacetic acid in 50 ml. of acetone is added 1.2 ml. of N-methylmorpholine. The resulting mixture is cooled to -20° C., and a solution of 1.09 g. of ethyl chloroformate in 20 ml. of acetone is added dropwise during 10 minutes. Stirring is continued at -20° C. for 60 minutes, and then a solution of 4.61 g. of 6'-aminopenicillanoyloxymethyl penicillanate 1,1-dioxide in 50 ml. of acetone is added dropwise at -20° C. Stirring is continued at -20° C. for 60 minutes, at 0° C. for 30 minutes and at 25° C. for 30 minutes. At this point the solvent is removed by evaporation in vacuo, and the residue is partitioned between ethyl acetate and water at pH 2.5. The layers are separated and the aqueous layer is discarded. Fresh water is added and the pH is raised to 8.5. The layers are shaken and separated, and then the organic layer is discarded. Fresh ethyl acetate is added and the pH is again adjusted to 2.5. The layers are shaken and separated. The ethyl acetate layer is washed with water, and then it is dried. Evaporation of the ethyl acetate layer in vacuo affords the title compound.
EXAMPLE 23
The procedure of Example 22 is repeated, except that the 2-(4-ethyl-2,3-dioxopiperazinocarbonylamino)-2-phenylacetic acid is replaced by:
2-(2-oxoimidazolidinocarbonylamino)-2-phenylacetic acid,
2-(3-acetyl-2-oxoimidazolidinocarbonylamino)-2-phenylacetic acid,
2-(3-butyryl-2-oxoimidazolidinocarbonylamino)-2-phenylacetic acid,
2-(3-methylsulfonyl-2-oxoimidazolidinocarbonylamino)-2-phenylacetic acid and
2-(3-isopropylsulfonyl-2-oxoimidazolidinocarbonylamino)-2-phenylacetic acid, respectively. This affords:
6'-(2-[2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide,
6'-(2-[3-acetyl-2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide,
6'-(2-[3-butyryl-2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide,
6'-(2-[3-methylsulfonyl-2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide and
6'-(2-[3-isopropylsulfonyl-2-oxoimidazolidinocarbonylamino]-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide, respectively.
EXAMPLE 24
6'-Aminopenicillanoyloxymethyl Penicillanate 1,1-Dioxide
To a solution of 1.2 g. of 6'-nitrobenzyloxycarbonylamino)penicillanoyloxymethyl penicillanate 1,1-dioxide in a mixture of 30 ml. of water and 50 ml. of tetrahydrofuran was added 1 drop of acetic acid (pH dropped to 4.5), followed by 1.2 g. of 10% palladium-on-carbon. The mixture was shaken under an atmosphere of hydrogen, at ca. 50 psig pressure, for 1.5 hours. The mixture was then filtered and the residue was washed with water and with tetrahydrofuran. The tetrahydrofuran-water, water and tetrahydrofuran solutions were combined and the pH was adjusted to 8.5. The resulting solution was extracted with ethyl acetate, and the ethyl acetate extract was dried (Na 2 SO 4 ). The dried solution was evaporated in vacuo giving 600 mg. of crude material.
The crude material was chromatographed on silica gel, eluting with 3:1 ethyl acetate-hexane, which afforded 200 mg. of the title compound (23% yield). The IR spectrum (KBr disc) showed an absorption at 1783 cm -1 . The NMR spectrum (CDCl 3 ) showed absorptions at 5.9 (s), 5.5 (m), 4.63 (m,), 4.5 (s), 3.5 (d), 1.7 (s), 1.6 (s), 1.5 (s) and 1.45 (s) ppm.
6'-Aminopenicillanoyloxymethyl penicillanate 1,1-dioxide will form acid-addition salts. The salts are prepared in conventional fashion, i.e. using the methods described earlier for the formation of acid-addition salts of those compounds of formula I which have an amino group as part of the group R 1 .
EXAMPLE 25
Chloromethyl Penicillanate 1,1-Dioxide
To a stirred solution of 24 g. of penicillanic acid 1,1-dioxide in 125 ml. of N,N-dimethylformamide was added 9.5 ml. of diisopropylethylamine, followed by 45 ml. of chloroiodomethane. Stirring was continued overnight and then the reaction mixture was added to 300 ml. of water. The pH was adjusted to 8.5, and then the mixture was extracted with ethyl acetate. The extract was washed with water, followed by saturated sodium chloride solution, and then it was dried over sodium sulfate. The dried extract was concentrated to dryness in vacuo to give the crude product as a gum (8.9 g.).
The crude product was combined with some additional material of comparable quality, and it was chromatographed on silica gel eluting with 1:1 ethyl acetate-hexane. This afforded the title compound which showed only a single spot when assayed by thin-layer chromatography. The IR spectrum (KBr disc) showed an absorption at 1801 cm -1 . The NMR spectrum (CDCl 3 ) showed absorptions at 6.0 (d, 1H, J=6 Hz), 5.7 (d, 1H, J=6 Hz), 4.7 (t, 1H, J=3.5 Hz), 4.5 (s, 1H), 3.55 (d, 2H, J=3.5 Hz), 1.7 (s, 3H) and 1.5 (s, 3H) ppm.
EXAMPLE 26
The procedure of Example 25 is repeated, except that the chloroiodomethane used therein is replaced by an equimolar amount of bromoiodomethane, diiodomethane, di(methylsulfonyloxy)methane, di(isobutylsulfonyloxy)methane, di(benzenesulfonyloxy)methane and di(4-toluenesulfonyloxy)methane. This affords:
bromomethyl penicillanate 1,1-dioxide,
iodomethyl penicillanate 1,1-dioxide,
methylsulfonyloxymethyl penicillanate 1,1-dioxide,
isobutylsulfonyloxymethyl penicillanate 1,1-dioxide,
benzenesulfonyloxymethyl penicillanate 1,1-dioxide and
4-toluenesulfonyloxymethyl penicillanate 1,1-dioxide, respectively.
EXAMPLE 27
Chloromethyl 6-(2-Benzyloxycarbonylamino-2-phenylacetamido)penicillanate
To a 1 liter 3-neck round bottom flask equpped with a magnetic stirrer and containing 6-(2-benzyloxycarbonylamino-2-phenylacetamido)penicillanic acid (99.30 g.) in dimethylsulfoxide (500 ml.) cooled to 15° C. was added dropwise over a 15 minute period triethylamine (28.5 ml.). To this solution was added potassium iodide (2.0 g.) followed by the dropwise addition of iodochloromethane (143 g.) over a 15 minute period. The reaction was stirred at room temperature overnight. To this solution was added ethyl acetate (1 liter). The resultant organic layer was washed with brine (3×300 ml.) and water (1×300 ml.). The combined aqueous wash was reextracted with ethyl acetate (300 ml.). The ethyl acetate extracts were dried over magnesium sulfate, filtered and concentrated to afford 116 g. of crude product. Silica gel (1 kg.) chromatography using chloroform afforded 24.6 g. (23%) of the title compound as a light yellow foam, m.p. 75°-77° C.
EXAMPLE 28
6'-(2-Benzyloxycarbonylamino-2-phenylacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
To a 500 ml. round bottom flask equipped with a paddle stirrer and containing chloromethyl 6-(2-benzyloxycarbonylamino-2-phenylacetamido)penicillanate (20 g.) in dimethylsulfoxide (120 ml.) at room temperature was added sodium penicillanate 1,1-dioxide (9.6 g.) followed by potassium iodide (600 mg.). The reaction was allowed to stir overnight. An additional charge (2.4 g.) of sodium penicillanate 1,1-dioxide was added and the reaction mixture was stirred for an additional 6 hours. The crude reaction mixture was then poured into ice water (600 ml.) and extracted with ethyl acetate (1×500 ml., 3×200 ml.). The organic extracts were backwashed with water (2×500 ml.) and brine (1×500 ml.) and dried over magnesium sulfate in the presence of activated carbon. The solution was filtered and concentrated in vacuo to afford 23.9 g. of crude product. Silica gel (250 g.) chromatography using chloroform afforded 14.5 g. (53%) of the title product, m.p. 80°-112° C.
EXAMPLE 29
6'-(2-Amino-2-phenylacetamido)penicillanoyloxymethyl Penicillanate 1,1-Dioxide Hydrochloride
To a 500 ml. hydrogenation flask, containing 6'-(2-benzyloxycarbonylamino-2-phenylacetamido)penicillanoyloxymethyl penicillanate 1,1-dioxide (5.50 g.) in tetrahydrofuran (75 ml.) were added water (75 ml.) acetic acid (1 drop) and 10% palladium on carbon (13.75 g.). The mixture was purged with nitrogen and then it was shaken under an atmosphere of hydrogen at 47 psig pressure for 30 minutes. An additional catalyst charge (3.00 g.) was added and the mixture was hydrogenated for an additional 15 minutes. The mixture was purged with nitrogen and filtered through a celite pad. The catalyst was washed with tetrahydrofuran (50 ml.) and water (30 ml.). The black solution was refiltered. 1.0 N Hydrochloric acid (7.54 ml.) was then added to the aqueous solution which was cooled to 0° C. The pH of this yellow solution was 1.7. Tetrahydrofuran was then removed in vacuo and the resultant aqueous solution was saturated with sodium chloride and extracted with ether (2×100 ml.). The aqueous solution was then reextracted with methylene chloride (5×50 ml.). The organic extracts were backwashed with saturated brine (2×50 ml.), dried over magnesium sulfate and concentrated to ca. 100 ml. The crude product was precipitated with hexane (100 ml.) and filtered to afford 3.2 g. of a cream colored solid. The crude product was redissolved in methylene chloride (50 ml.) and precipitated slowly with hexane (40 ml.) to afford after drying (23°/1.6 mm.) 2.78 g. (58%) of the title product, m.p. 190° C.
PREPARATION 1
6-(2-Benzyloxycarbonylamino-2-phenylacetamido)penicillanic Acid
To a mixture of 100 ml. of water and 50 ml. of tetrahydrofuran was added 10.1 g. of 6-(2-amino-2-phenylacetamido)penicillanic acid trihydrate and then the pH was adjusted to 8.0. To the solution so obtained was added benzyl chloroformate (3.6 ml.), dropwise, with stirring, at a pH of 8.0-8.5. Stirring was continued until the pH became stable, and then the solution was extracted with ethyl acetate. The ethyl acetate extract was discarded, and the pH of the aqueous phase was lowered to 2.0. The acidified aqueous phase was extracted with ethyl acetate, and the latter organic phase was dried and evaporated in vacuo. This afforded 11.4 g. of the title compound (94% yield). The NMR spectrum (CDCl 3 /DMSO-d 6 ) showed absorptions at 8.2 (d, 1H), 7.6-7.2 (m, 10H), 7.0-6.6 (m, 1H), 5.6-5.3 (m, 3H), 5.1 (s, 2H), 4.3 (s, 1H) and 1.5 (2 s's, 6H) ppm.
PREPARATION 2
6-(2-Benzyloxycarbonylamino-2-[4-hydroxyphenyl]acetamido)penicillanic Acid
The title compound was prepared from 6-(2-amino-2-[4-hydroxyphenyl]acetamido)penicillanic acid and benzyl chloroformate, using the procedure of Preparation 1. Yield 97%. The NMR spectrum of the product (CDCl 3 /DMSO-d 6 ) showed absorptions at 7.6-7.0 (m, 8H), 7.0-6.6 (d, 2H, J=8 Hz), 5.6-5.2 (m, 3H), 5.2-5.0 (s, 2H) and 1.5 (broad s, 6H) ppm.
PREPARATION 3
6-(2-[4-Nitrobenzyloxycarbonylamino]-2-phenylacetamido)penicillanic Acid
The title compound was prepared from 6-(2-amino-2-phenylacetamido)penicillanic acid and 4-nitrobenzyl chloroformate, using the procedure of Preparation 1.
The product thus obtained was partitioned between ethyl acetate and water and the pH was adjusted to 8.5 using potassium hydroxide. The ethyl acetate layer was removed and discarded, and the aqueous phase was lyophilized. This afforded the potassium salt of the title compound. Yield 82%. The NMR spectrum (CDCl 3 /DMSO-d 6 ) showed absorptions at 8.2 (d, 2H, J=8 Hz), 7.8-7.2 (m, 7H), 5.8-5.4 (m, 3H), 5.2 (s, 2H), 4.2 (s, 1H), 4.0-3.6 (broad s, 2H) and 1.8-1.2 (m, 6H) ppm.
PREPARATION 4
6-(2-[4-Nitrobenzyloxycarbonylamino]-2-[4-hydroxyphenyl]acetamido)penicillanic Acid
The title compound was prepared from 6-(2-amino-2-[4-hydroxyphenyl]acetamido)penicillanic acid and 4-nitrobenzyl chloroformate, using the procedure of Preparation 1. The product was converted into its potassium salt using the method described in Preparation 3.
PREPARATION 5
Chloromethyl 6-(2-Benzyloxycarbonylamino-2-phenylacetamido)penicillanate
A mixture of 1.04 g. of potassium 6-(2-benzyloxycarbonylamino-2-phenylacetamido)penicillanate, 0.87 ml. of chloroiodomethane and 10 ml. of N,N-dimethylformamide was stirred at ambient temperature overnight. The reaction mixture was poured into 50 ml. of water, and the pH was raised to 8.5. The acidified mixture was extracted with ethyl acetate. The extracts were combined, washed with water and then with saturated sodium chloride solution, and then they were dried (Na 2 SO 4 ). Evaporation in vacuo gave 650 mg. (61% yield) of the title compound. The IR spectrum (KBr disc) showed an absorption at 1802 cm -1 . The NMR spectrum (CDCl 3 ) showed absorptions at 7.4 (s, 10H), 7.3-7.0 (m, 2H), 6.3 (d, 1H, J=7 Hz), 6.0-5.2 (m, 5H), 5.1 (s, 1H), 4.4 (s, 1H) and 1.5 (m, 6) ppm.
PREPARATION 6
Chloromethyl 6-(2-[4-Nitrobenzyloxycarbonylamino]-2-phenylacetamido)penicillanate
The title compound was prepared from potassium 6-(2-[4-nitrobenzyloxycarbonylamino]-2-phenylacetamido)penicillanate and chloroiodomethane according to the procedure of Preparation 5. The yield of crude product was 68%.
A quantity (2.1 g.) of the above crude product was chromatographed on silica gel using 1:1 ethyl acetate-hexane as eluant, to give material showing only one spot when assayed by thin-layer chromatography.
PREPARATION 7
Chloromethyl 6-(2-[4-Nitrobenzyloxycarbonylamino]-2-[4-hydroxyphenyl]acetamido)penicillanate
The title compound was prepared from potassium 6-(2-[4-nitrobenzyloxycarbonylamino]-2-[4-hydroxyphenyl]-acetamido)penicillanate and chloroiodomethane according to the procedure of Preparation 5. The yield of crude product was 68%.
The crude product was chromatographed on silica gel using 2:1 ethyl acetate-hexane as eluant, to give a 29% yield of material showing only one spot when assayed by thin-layer chromatography. The NMR spectrum (CDCl 3 ) showed absorptions at 8.2 (d, 2H, J=8 Hz), 7.7-7.0 (m, 6H), 6.9-6.3 (m, 3H), 6.0-5.3 (m, 5H), 5.2 (s, 2H), 4.4 (s, 1H) and 1.5 (d, 6H) ppm.
PREPARATION 8
6'-(4-Nitrobenzyloxycarbonylamino)penicillanoyloxymethyl Penicillanate 1,1-Dioxide
To a stirred solution of 4.32 g. of potassium 6-(4-nitrobenzyloxycarbonylamino)penicillanate in 60 ml. of dimethyl sulfoxide was added 2.53 g. of chloromethyl penicillanate 1,1-dioxide, followed by a few milligrams of sodium iodide. Stirring was continued for 16 hours, and then the mixture was poured in 200 ml. of water. The pH was adjusted to 8.5, and the resulting mixture was extracted with ethyl acetate. The ethyl acetate extracts were washed with water followed by saturated sodium chloride solution. The resulting solution was evaporated in vacuo to give 1.57 g. of crude material.
The crude material was chromatographed on silica gel, eluting with ethyl acetate, to give 1.2 g. of the title compound. The NMR spectrum showed absorptions at 8.25 (d), 7.50 (d), 5.95 (s), 5.73 (m), 5.55 (broad s), 5.23 (s), 4.75 (t), 4.46 (s), 4.44 (s), 3.46 (s), 3.44 (s), 1.72 (s), 1.65 (s), 1.52 (s) and 1.40 (s) ppm.
PREPARATION 9
6-(2-Benzyloxycarbonylamino-2-phenylacetamido)penicillanic Acid
To a 3 liter 3-neck round bottom flask equipped with a paddle stirrer and containing 6-(2-amino-2-phenylacetamido)penicillanic acid trihydrate (121.04 g.), tetrahydrofuran (550 ml.), and water (1000 ml.) cooled to 5° C. was added 10% sodium hydroxide (˜108 ml.) until the pH was ˜7.7. Over a 45 minute period with cooling, benzylchloroformate (53.87 g.) and 10% sodium hydroxide (˜108 ml.) were simultaneously added while the pH was maintained between 8.0-8.5. The reaction mixture was stirred with cooling for an additional hour after completion of the addition. The crude reaction mixture was concentrated in vacuo to remove the tetrahydrofuran. The aqueous solution was extracted with ethyl acetate (2×250 ml.). This organic extract was discarded. The aqueous solution was cooled to 5° C., ethyl acetate (500 ml.) was added, and the pH was adjusted to 2.0 using 6 N hydrochloric acid (50 ml.). The organic layer was separated and the aqueous was reextracted with ethyl acetate (3×250 ml.). The combined organic extracts were washd with brine (100 ml.), dried over magnesium sulfate, filtered and concentrated to afford crude product which was slurried with ether and filtered. The ether filtrate was concentrated to afford a white foam which was slurried with hexane and also filtered. The combined crude products were dried in vacuo overnight to yield 137.8 g. (95%) of the title compound, m.p. 144°-145° C.
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6'-Acylaminopenicillanoyloxymethyl esters of penicillanic acid 1,1-dioxide and useful as antibacterial agents. The 6'-aminopenicillanoyloxymethyl ester, halomethyl esters, alkylsulfonyloxymethyl esters and arylsulfonyloxymethyl esters of penicillanic acid 1,1-dioxide are all useful intermediates for the aforesaid antibacterial agents.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a coupling lens forming an optical system of a device, such as an optical information recording/reproducing device for recording information to and/or reproducing information from an optical disc.
[0002] In general, an optical information recording/reproducing device is configured such that the degree of divergence of a light beam emitted by a light source is converted by a coupling lens and the converted light beam is converged by an objective lens onto a record surface of an optical disc, such as a CD or a DVD, being used. Incidentally, in this specification, the “optical information recording/reproducing devices” include devices for both information reproducing and information recording, devices exclusively for information reproducing, and devices exclusively for information recording. In the following, the term “compatibility” is used to mean that the optical information recording/reproducing device ensures the information reproducing and/or information recording with no need of component replacement even when the optical disc being used is switched.
[0003] In most cases, lenses of the above described types provided in optical information recording/reproducing devices are made of resin. Therefore, the refractive index of such a lens varies depending on change in environmental conditions, such as temperature variations. More specifically, the actual refractive index may change from a design refractive index defined when the lens is designed. The change in refractive index of a lens leads to change of a positional relationship between an object point and an image point with respect to the position of the lens.
[0004] It is noted that a lens made of resin has a linear expansion coefficient larger than that of a lens made of glass. Such a property of a lens made of resin causes a considerable amount of change of the positional relationship between an object point and an image point with respect to the position of the lens.
[0005] Even if change of the positional relationship between an object point and an image point with respect to the position of the objective lens is caused due to change of the refractive index of the objective lens, the optical information recording/reproducing device is able to cancel the effect of the change in refractive index by executing a focusing function which is one of primary functions of the optical information recording/reproducing device.
[0006] However, if change in refractive index of the coupling lens which is placed only on an approaching optical path of a light beam proceeding to an optical disc (but is not placed on a returning optical path of the light beam returning from the optical disc) occurs, the following problems occur.
[0007] First, the light beam emerging from the coupling lens may have an unintended degree of divergence. If the degree of divergence of the light beam emerging from the coupling lens changes, the spherical aberration is caused. In this case, it becomes difficult to form a suitable beam spot for information recording or information reproducing on a record surface of the optical disc. Second, since typically a photoreceptor for receiving light reflected from the record surface of the optical disc is placed at a position having a conjugate relationship with an image point of the coupling lens, the conjugate relationship is lost if the image point of the coupling lens changes due to change in refractive index or linear expansion and thereby it may become difficult for the photoreceptor to execute an accurate detecting operation.
[0008] Examples of configurations for solving the above described problems are discussed in Japanese Patent Provisional Publications Nos. 2001-159731A (hereafter, referred to as JP2001-159731A) and 2003-114382A (hereafter, referred to as JP 2003-114382A).
[0009] The coupling lens disclosed in JP2001-159731A is provided with a diffraction structure so that the problem that the degree of divergence of a light beam emerging from a coupling lens changes due to change in refractive index can be solved. The coupling lens disclosed in JP 2003-114382A is also provided with a diffraction structure so that the problem that an image point relative to an object point changes due to change in refractive index can be solved. However, it is noted that the diffraction structure increases the manufacturing difficulty of the coupling lens and thereby increases the manufacturing cost of the coupling lens.
SUMMARY OF THE INVENTION
[0010] The present invention is advantageous in that it provides at least one of a coupling lens capable of suppressing change of a relative positional relationship between an object point and an image point due to change in refractive index while achieving a low cost and a simple structure, and an optical information recording/reproducing device in which such a coupling lens is employed.
[0011] According to an aspect of the invention, there is provided a coupling lens used in an optical information recording/reproducing device for recording information to and/or reproducing information from an optical disc. The coupling lens includes a first surface and a second surface, wherein the coupling lens is configured to satisfy a following condition (1):
[0000] −0.80 ≦Z≦ 0.40 (1),
[0012] wherein a value Z is obtained from a following equation (E1):
[0000]
Z
=
n
(
L
′
)
L
′
=
(
A
-
B
)
(
D
-
E
)
-
(
F
-
G
)
(
H
-
I
)
.
where
,
A
=
t
n
2
B
=
tL
n
2
r
1
D
=
-
t
n
E
=
(
1
-
1
n
)
tL
r
1
-
L
F
=
t
n
2
r
2
G
=
-
(
r
2
-
r
1
)
+
(
1
-
1
n
2
)
t
r
1
r
2
L
H
=
1
-
(
1
n
-
1
)
t
r
2
I
=
-
(
r
2
-
r
1
)
(
n
-
1
)
+
(
n
+
1
n
-
2
)
t
r
1
r
2
L
(
E1
)
[0013] r1 denotes a curvature radius of the first surface the coupling lens, r2 denotes a curvature radius of the second surface of the coupling lens, n denotes a design refractive index of the coupling lens, L denotes a working distance defined for an object point, and L′ denotes an working distance defined for an image point.
[0014] By configuring the coupling lens such that the value Z satisfy the above described condition, it becomes possible to maintain a relative positional relationship between an object point and an image point at a suitable state without using a diffraction structure.
[0015] In at least one aspect, the coupling lens may further satisfy a following condition:
[0000] −0.41 ≦Z≦ 0.23 (2).
[0016] According to another aspect of the invention, there is provided an optical information recording/reproducing device for recording information to and/or reproducing information from an optical disc, which includes a light source that emits a light beam, the above described coupling lens that changes a degree of divergence of the light beam emitted by the light source, and an objective lens that converges the light beam passed through the coupling lens onto a record surface of the optical disc.
[0017] In at least one aspect, the light source may be located at a position corresponding to the object point of the coupling lens.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0018] FIG. 1 illustrates a general configuration of an optical information recording/reproducing device according to an embodiment.
[0019] FIG. 2 is an enlarged view illustrating an optical path from a light source to a coupling lens.
[0020] FIG. 3 is an explanatory illustration for explaining a configuration of the coupling lens.
[0021] FIG. 4 is a graph illustrating the relationship between change in refractive index and the image working distance for each of first and second examples and a comparative example.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] Hereinafter, an embodiment according to the invention is described with reference to the accompanying drawings.
[0023] In the following, an optical information recording/reproducing device 100 (see FIG. 1 ) according to an embodiment is described. The optical information recording/reproducing device 100 according to the embodiment has the compatibility with three types of optical discs of different standards concerning optical properties, such as protective layer thicknesses and recording densities.
[0024] In the following explanation, an optical disc of a type (one of the three types) having the highest recording density (e.g., a new-standard optical disc such as HD DVD or BD) will be referred to as an “optical disc D1”, an optical disc of a type having a relatively low recording density compared to the optical disc D 1 (DVD, DVD-R, etc.) will be referred to as an “optical disc D2”, and an optical disc of a type having the lowest recording density (CD, CD-R, etc.) will be referred to as an “optical disc D3” for convenience of explanation.
[0025] If the protective layer thicknesses of the optical discs D 1 -D 3 are defined as t 1 , t 2 , t 3 , respectively, the protective layer thicknesses satisfy a following relationship.
[0000] t1≦t2<t3
[0026] In order to carry out the information reproducing/recording on each of the optical discs D 1 -D 3 , the NA (Numerical Aperture) required for the information reproducing/recording has to be varied properly so that a beam spot suitable for a particular recording density of each optical disc can be formed. When the optimum design numerical apertures required for the information reproducing/recording on the three types of optical discs D 1 , D 2 and D 3 are defined as NA 1 , NA 2 and NA 3 , respectively, the numerical apertures (NA 1 , NA 2 , NA 3 ) satisfy the following relationships:
[0000] (NA1>NA3) and (NA2>NA3)
[0027] Specifically, for the information recording/reproducing on the optical discs D 1 and D 2 having high recording densities, a relatively large NA is required since a relatively small spot has to be formed. On the other hand, for the information recording/reproducing on the optical disc D 3 having the lowest recording density, the required NA is relatively small. Incidentally, each optical disc is set on a turntable (not shown) and rotated at high speed when the information recording/reproducing is carried out.
[0028] In cases where three types of optical discs D 1 -D 3 (having different recording densities) are used as above, multiple laser beams having different wavelengths are selectively used by the optical information recording/reproducing device so that a beam spot suitable for each recording density can be formed on the record surface of the optical disc being used.
[0029] Specifically, for the information recording/reproducing on the optical disc D 1 , a “first laser beam” having the shortest wavelength is emitted from a light source so as to form the smallest beam spot on the record surface of the optical disc D 1 . On the other hand, for the information recording/reproducing on the optical disc D 3 , a “third laser beam” having the longest wavelength is emitted from a light source so as to form the largest beam spot on the record surface of the optical disc D 3 . For the information recording/reproducing on the optical disc D 2 , a “second laser beam” having a wavelength longer than that of the first laser beam and shorter than that of the third laser beam is emitted from a light source so as to form a relatively small beam spot on the record surface of the optical disc D 2 .
[0030] FIG. 1 illustrates a general configuration of the optical information recording/reproducing device 100 according to the embodiment. As shown in FIG. 1 , the optical information recording/reproducing device 100 includes a light source 1 A which emits the first laser beam, a light source 2 A which emits the second laser beam, a light source 3 A which emits the third laser beam, a coupling lens CL, a collimator lens 20 , beam splitters 41 and 42 , a half mirror 43 , a photoreceptor 44 , and an objective lens 10 .
[0031] Since numerical apertures for the three types of optical discs are different from each other, the optical information recording/reproducing device 100 needs to change the numerical aperture depending on the type of the optical disc being used. Therefore, the optical information recording/reproducing device 100 may be provided with an aperture stop for limiting the beam diameter of the third laser beam on an optical path from the light source 3 A to the objective lens 10 .
[0032] As shown in FIG. 1 , for information recording or the information reproducing for each of the optical discs D 1 and D 2 , the laser beam emitted from each of the light sources 1 A and 2 A is directed to a common path through the beam splitter 42 and the half mirror 43 , and is converted into a collimated beam by the collimator lens 20 . The laser beam which passed through the collimator lens 20 is then incident on the objective lens 10 .
[0033] When the information recording or the information reproducing for the optical disc D 3 is performed, the third laser beam emitted from the light source 3 A is incident on the coupling lens CL. FIG. 2 is an enlarged view illustrating an optical path from the light source 3 A to the coupling lens CL. In FIG. 2 , the beam splitters 41 and 42 are omitted for the sake of simplicity. The coupling lens CL changes the degree of divergence of the third laser beam. The third laser beam which emerged from the coupling lens is deflected by the beam splitter 41 , and is then incident on the collimator lens 20 . The third laser beam collimated by the collimator lens 29 is then incident on the objective lens 10 .
[0034] Since the first to third laser beams having different wavelengths are selectively used for the optical discs D 1 -D 3 in the optical information recording/reproducing device 100 , the spherical aberration varies depending on change in refractive index of the objective lens 10 and the difference between protective layer thicknesses of the optical discs D 1 -D 3 .
[0035] The optical information recording/reproducing device 100 is configured to achieve the compatibility with the three types of optical discs D 1 -D 3 by correcting the spherical aberration caused when the optical discs is switched between the three types of optical discs. For example, at least one of surfaces of the objective lens 10 is provided with a diffraction structure having diffraction effects on each of the three types of laser beams. The diffraction structure has a plurality of refractive surface zones (annular zones) concentrically formed about an optical axis AX (see FIG. 1 ). The plurality of annular zones are divided by minute steps formed between adjacent ones of the plurality of annular zones. Each step is designed to add a predetermined optical path length to the first laser beam.
[0036] The laser beam which passed through the objective lens 10 converges onto the optical disc being used. Each laser beam reflecting from the record surface of the optical disc being used passes through the half mirror 43 , and is then detected by the photoreceptor 44 .
[0037] By converting each laser beam to be incident on the objective lens 10 into the collimated beam, it becomes possible to suppress the occurrence of off-axis aberration, such as a coma, due to shifting of the objective lens 10 during a tracking operation.
[0038] FIG. 3 is an explanatory illustration for explaining a configuration of the coupling lens CL. As shown in FIG. 3 , the coupling lens CL has a first surface CL 1 and a second surface CL 2 . In this embodiment, the coupling lens CL is designed such that at least one of the first and second surfaces CL 1 and CL 2 is an aspherical surface to suitably correct aberrations. It should be understood that both of the first and surfaces CL 1 CL 2 may be formed to be aspherical surfaces. If one of the first and the second surfaces CL 1 and CL 2 is formed to be an aspherical surface, one of the spherical aberration and offense against the sine condition can be corrected. If both of the first and second surfaces CL 1 and CL 2 are formed to be aspherical surfaces, both of the spherical aberration and offense against the sine condition can be properly corrected.
[0039] A shape of an aspherical surface is expressed by a following equation:
[0000]
X
(
h
)
=
ch
2
1
+
1
-
(
1
+
K
)
c
2
h
2
+
∑
i
=
2
A
2
i
h
2
i
[0040] where, X(h) represents a SAG amount which is a distance between a point on the aspherical surface at a height of h from the optical axis and a plane tangential to the aspherical surface at the optical axis, symbol c represents curvature (1/r) on the optical axis, K is a conical coefficient, and A 2i represents an aspherical coefficient of an even order larger than or equal to the fourth order.
[0041] Hereafter, “r1” denotes a curvature radius of the first surface CL 1 of the coupling lens CL, “r2” denotes a curvature radius of the second surface CL 2 of the coupling lens CL, “n” represents a design refractive index of the coupling lens CL, and “L” denotes a working distance defined for an object point (hereafter, frequently referred to as an object working distance). Actually, in the optical information recording/reproducing device 100 , a light source is located and fixed at the object point of the first surface CL 1 . Therefore, in the following, a distance between the object point and a lens surface (i.e., an incident side surface CL 1 ) facing the object point is regarded as a constant value. That is, change of a relative positional relationship between the object point and the image point is regarded as change of a distance L′ (a working distance defined for an image point) between the image point and the exit side surface CL 2 of the coupling lens CL. Hereafter, the distance L′ is frequently referred to as an image working distance.
[0042] The coupling lens CL is arranged in the optical information recording/reproducing device 100 such that a value Z obtained from the following equation (E1) satisfies a predetermined condition.
[0000]
Z
=
n
(
L
′
)
L
′
=
(
A
-
B
)
(
D
-
E
)
-
(
F
-
G
)
(
H
-
I
)
.
where
,
A
=
t
n
2
B
=
tL
n
2
r
1
D
=
-
t
n
E
=
(
1
-
1
n
)
tL
r
1
-
L
F
=
t
n
2
r
2
G
=
-
(
r
2
-
r
1
)
+
(
1
-
1
n
2
)
t
r
1
r
2
L
H
=
1
-
(
1
n
-
1
)
t
r
2
I
=
-
(
r
2
-
r
1
)
(
n
-
1
)
+
(
n
+
1
n
-
2
)
t
r
1
r
2
L
(
E1
)
[0043] The value Z obtained from the above described equation corresponds to a value obtained by formulating the image working distance L′ with the above described parameters r1, r2, t, n and L, differentiating the formulated value with the design refractive index n, and then normalizing the differentiated value by dividing the differentiated value with the image working distance L′.
[0044] In this embodiment, the value Z satisfies the following condition (1). The following condition (2) may be satisfied.
[0000] −0.80≦ Z≦ 0.40 (1)
[0000] −0.41≦ Z≦ 0.23 (2)
[0045] By designing the coupling lens CL to satisfy the condition (1), it is possible to maintain the suitable positional relationship between the object point and the image point even when change in refractive index occurs, without arranging a diffraction structure on the coupling lens. By appropriately controlling the value of each parameter, it is possible to satisfy required specifications including a focal length and magnification. Such advantages become more noticeable when the condition (2) is satisfied.
[0046] If a coupling lens having the value Z outside the range defined in the condition (1) is employed in the optical information recording/reproducing device 100 , the image working distance largely changes to the extent that the accurate information recording/reproducing is badly affected.
[0047] Hereafter, two concrete examples of the coupling lens CL according to the embodiment are described.
FIRST EXAMPLE
[0048] Table 1 shows a concrete numerical configuration of the coupling lens CL according to a first example. Table 2 shows values of Z and the parameters concerning the above described equation (E1) of the coupling lens shown in Table 1.
[0000]
TABLE 1
focal length
5.761
magnification
1.262
r1
3.240
r2
−116.800
t
1.700
L
−1.166
L′
−2.581
n
1.550
[0000]
TABLE 2
A
0.708
B
−0.255
C
−1.097
D
0.949
E
−0.006
F
0.367
G
0.995
H
0.202
Z
0.000
[0049] The image working distance L′ shown in Table 1 is a design value. As shown in Table 2, the coupling lens CL according to the first example satisfies the conditions (1) and (2).
SECOND EXAMPLE
[0050] The coupling lens CL according to a second example is designed such that both of the first and second surfaces CL 1 and CL 2 are aspherical surfaces. Table 3 shows a concrete numerical configuration of the coupling lens CL according to the second example. Table 4 shows the conical coefficient and aspherical coefficients defining the first surface CL 1 of the coupling lens CL. Table 5 shows the conical coefficient and aspherical coefficients defining the second surface CL 2 of the coupling lens CL.
[0000]
TABLE 3
focal length
189.049
magnification
1.125
effective diameter (h)
3.000
of CL 1
r1
−11.500
r2
−10.834
t
1.500
L
−11.779
L′
−14.959
n
1.550
[0000]
TABLE 4
K
0.00000
A4
1.3780E−04
A6
2.4020E−06
[0000]
TABLE 5
K
0.00000
A4
8.2210E−05
A6
1.5340E−06
[0051] Table 6 shows values of Z and the parameters concerning the above described equation (E1) of the coupling lens CL shown in Table 3.
[0000]
TABLE 6
A
0.624
B
0.639
C
−0.968
D
12.324
E
−0.058
F
0.146
G
0.951
H
0.062
Z
0.230
[0052] As shown in Table 6, the coupling lens CL according to the second example satisfies the conditions (1) and (2).
COMPARATIVE EXAMPLE
[0053] Hereafter, a coupling lens according to a comparative example is described. The coupling lens according to the comparative example is configured to suppress the spherical aberration and offense against the sine condition as low as possible without using an aspherical surface. That is, the design of the comparative example is based on a conventional technique.
[0054] Table 7 shows a concrete numerical configuration of the coupling lens CL according to the comparative example. Table 8 shows values of Z and the parameters concerning the above described equation (E1) of the coupling lens shown in Table 7.
[0000]
TABLE 7
focal length
17.995
magnification
2.000
r1
−6.743
r2
−3.579
t
1.000
L
−5.000
L′
−11.817
n
1.550
[0000]
TABLE 8
A
0.416
B
0.309
C
−0.645
D
5.263
E
−0.116
F
0.776
G
0.901
H
0.401
Z
1.768
[0055] FIG. 4 is a graph illustrating the relationship between change in refractive index and the image working distance L′ for each of the first and second examples and the comparative example. As shown in FIG. 4 , the coupling lens CL according to each of the first and second examples satisfying the conditions (1) and (2) has the change rate of the image working distance with respect to the change in refractive index being approximately equal to zero. That is, by employing the coupling lens CL according to each of the first and second examples in the optical information recording/reproducing device 100 , even if the refractive index of the coupling lens CL changes due to, for example, temperature variations during use of the optical disc D 3 , the photoreceptor 44 is able to constantly execute a suitable detection operation without being affected by the change in refractive index.
[0056] By contrast, the image working distance L′ of the coupling lens according to the comparative examples changes largely with the change in refractive index. That is, the coupling lens according to the comparative example shows the large change rate of the image working distance L′.
[0057] As described above, one of factors causing change in refractive index is temperature variation. If temperature changes, the linear expansion may occur in the coupling lens CL. In this regard, the coupling lens according to the embodiment is able to maintain the relative positional relationship between the object point and the image point even if such an undesirable phenomenon occurs.
[0058] Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, other embodiments are possible.
[0059] In the above described embodiment, the coupling lens is formed to be a biconvex lens. However, the coupling lens according to the embodiment may have various types of shapes while satisfying the above described conditions (1) and (2). For example, the coupling lens may have a meniscus shape depending on magnification, the lens thickness or a temperature change property of the object image distance.
[0060] This application claims priority of Japanese Patent Application No. P2007-276441, filed on Oct. 24, 2007. The entire subject matter of the applications is incorporated herein by reference.
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There is provided a coupling lens used in an optical information recording/reproducing device for recording information to and/or reproducing information from an optical disc. The coupling lens includes a first surface and a second surface, wherein the coupling lens is configured to satisfy a following condition (1):
−0.80≦ Z≦ 0.40 (1), wherein a value Z is obtained from a following equation (E1):
Z
=
n
(
L
′
)
L
′
=
(
A
-
B
)
(
D
-
E
)
-
(
F
-
G
)
(
H
-
I
)
.
(
E1
)
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BACKGROUND OF THE INVENTION
This invention relates to a simple method and control for identifying a low charge of refrigerant in a refrigerant system.
Refrigerant systems are utilized to condition an environment and may include air conditioners or heat pumps. In a traditional refrigerant system, refrigerant is routed between several components through sealed connections. Over time, and for various reasons, some of the refrigerant may escape the sealed system. This can result in there being a lower charge of refrigerant than would be desirable.
When there is a low charge of refrigerant, it becomes more difficult for the system to provide its function such as cooling air being directed into an environment. Additional load is put on the compressor, and the compressor may fail, or the system may not adequately condition the air being directed into the environment.
Thus, various methods have been utilized to identify a low charge of refrigerant. One simple method looks at whether the refrigerant from an evaporator being directed to a compressor, has excessively high super heat. A high super heat value is indicative of a low charge of refrigerant.
However, with modern refrigerant systems, the expansion valves directing the refrigerant to the evaporator are controlled electronically in response to the amount of super heat upon sensing high super heat, the control adjusts the expansion valve to result in the amount of super heat being moved downwardly. Such control can mask the low charge.
Thus, a simplified method of identifying a low charge of refrigerant that would be useful in complex refrigerant systems is desired.
SUMMARY OF THE INVENTION
In a disclosed embodiment of this invention, a method and a control programmed to perform the method take in various standard variables from a refrigerant system. As is known, and for various diagnostic purposes, pressure and temperature readings are taken at various points within a refrigerant system. These standard readings are utilized with this invention to determine the mass flow rate of refrigerant. The mass flow rate of refrigerant can be calculated in any one of several manners, and utilizing different ones of the standard variables. By comparing two of these mass flow calculations, the method determines whether the calculations are within a margin of error of each other. In a low charge situation, the mass flow rate calculations would be inaccurate, and thus different from each other. When a sufficient difference in calculated mass flow rates is identified, the control identifies the system as having a low charge.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a refrigerant system for performing the present invention.
FIG. 2 is a flow chart of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a refrigerant system 20 incorporating a compressor 22 for compressing refrigerant and delivering it to a condenser 24 . A fan 26 drives air over the condenser, and in an air conditioning mode, removes heat from the refrigerant in the condenser. Downstream of the condenser 24 is an expansion device 28 . In complex systems, this expansion device may be electronically controlled with a closed feedback loop based upon a super heat temperature of the refrigerant approaching the compressor 22 .
Downstream of the expansion device 28 is an evaporator 30 having a fan 32 for pulling air over the evaporator 30 and into an environment to be conditioned. Temperature readings may be taken on the air approaching the evaporator by sensor 50 , the air having passed over the evaporator by sensor 52 , the refrigerant approaching the evaporator by sensor 54 , the refrigerant downstream of the evaporator by sensor 56 , the pressure of the refrigerant approaching the compressor by sensor 58 , the temperature of the refrigerant approaching the compressor 22 by sensor 60 , and the pressure (sensor 62 ) and temperature (sensor 64 ) of the refrigerant downstream of the compressor. Such readings are already taken by many modern refrigerant systems and utilized for various diagnostic purposes.
A refrigerant mass flow rate for refrigerant passing through the expansion valve 28 may be calculated by a known equation such as:
m r1 =% C v √{square root over (Δp)} (1)
The refrigerant mass flow rate is a function of a differential pressure the valve (Δp) and the percentage of valve opening (%). C v is a characteristic constant of the valve. Using this predetermined valve characteristic, the refrigerant flow rate can be metered if the differential pressure is measurable.
It is possible that a constant differential pressure valve be used for refrigerant flow regulation, and in such a case, there is no need for the measurement of differential pressure across the valve. Other types of regulating valve require the direct measurement or indirect estimation of the differential pressure across the valve for flow rate calculation.
Shown in FIG. 1 are four sensors ( 50 , 52 , 54 , 56 ) monitoring the evaporator operation. The heat transfer equations for counter flow heat exchangers are:
Air side:
Q
=
m
a
c
p
1
(
T
1
in
-
T
1
out
)
SHR
(
2
)
Refrigerant side:
Q=m r1 ( h r1 −h r2 ) (3)
where
Q=rate of heat transfer, W
m a =mass flow rate of air kg/s
m r1 =mass flow rate of refrigerant kg/s
c p1 =specific heats of dry air, J/kgK
T 1 in/out=air temperature (sensors 50 , 52 ), ° C.
SHR=sensible heat ratio determined from the inlet and outlet air conditions
h r1 , h r2 =specific enthalpies of refrigerant vapor at inlet and outlet of evaporator, J/Kg
Refrigerant enthalpies h r1 , h r2 can be obtained from the refrigerant properties using the temperature and pressure measurement. Under the condition that SHR and air mass flow rate are known, the refrigerant flow rate can be solved from equations (2) and (3):
m
r
=
m
a
c
p
1
(
T
1
in
-
T
1
out
)
SHR
(
h
r
1
-
h
r
2
)
(
4
)
The refrigerant mass flow rate can also be estimated using the compressor model, obtained from the manufacturer data. A three-term model to approximate the theoretical model of volumetric flow rate of a compressor is given as:
V suc =( a−bP r c ) (5)
where a, b, c are constants estimated from the manufacturer calorimeter data
P
r
=
P
dis
P
suc
is the compressor pressure ratio, which is the ratio between discharge pressure (P dis , sensor 62 ) and suction pressure (P suc , sensor 58 ).
The volumetric flow rate is obtained using the density of refrigerant according to:
m r2 =V suc ρ (6)
where ρ is the density of refrigerant
For those who are skilled in this art, the refrigerant flow rate may also be calculated using a compressor model of a different format from (5).
The refrigerant flow rate estimated according to the compressor model in (6) should be close to the value calculated using either (1) or (4) under normal conditions. Under low charge conditions, large discrepancies between these two flow rate values will occur.
Consequently, an alarm indicator is defined as the difference, or residue (Θ) between two flow rate values:
Θ=| m r1 −m r2 | (7)
When the residue value exceeds a predetermined threshold, a decision is made that the charge is low. Tracking the estimated residue values over time also helps in predicting a gradual leaking of charge.
This technique can be extended to more complex systems that have multiple evaporators known as the multi-air conditioning systems. The extended low charge indicator is written as the compressor flow rate and the total of flow rates passing individual evaporators:
Θ = m r 1 - ∑ i m r 2 i ( 8 )
where i is the index number of evaporators in the system, and m r2 i is the refrigerant air flow rate through the i th heat evaporator.
Thus, the present invention utilizes existing sensors to provide an indication of a low charge.
Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
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A refrigerant system is provided with a method and a control programmed to perform the method, in which a low charge of refrigerant is identified. The mass flow of refrigerant through the system is calculated utilizing at least two different methods. The two calculated mass flow rates are compared, and if they differ by more than predetermined amount, a determination is made that there is a low charge of refrigerant within the system.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of provisional patent application Ser. No. 60/736,895 filed Nov. 16, 2005, which is incorporated herein by reference and is a continuation in part of patent application Ser. No. 11/377,839 filed Mar. 16, 2006.
TECHNICAL FIELD
[0002] This invention relates to the repair of boiler tubes. More specifically, it relates to a system for removing heat transfer fins from a section of boiler tube and for preparing the tube end to facilitate the repair of the boiler tube.
BACKGROUND OF THE INVENTION
[0003] Steam-generating boilers are generally large structures containing numerous boiler tubes, usually made of steel, that are in thermal contact with a burning fuel, such as coal. The burning fuel heats water circulating through the boiler tubes. The heated water, or more usually the resulting steam, is used to drive turbines for generation of electricity or other purposes. In order to facilitate thermal transfer to the water in a boiler tube, heat transfer fins are placed around the boiler tube. They are typically brazed or welded to the boiler tube by high frequency welding. Because of deterioration due to corrosion and the like, boiler tubes may require replacement. Ordinarily repair of a damaged boiler tube involves cutting and removal of the damaged section of the tube and replacement with a new section. The section of boiler tube to be replaced is generally cut out using a power saw or cutting torch. However, heat transfer fins on the boiler tube must first be removed to gain access to the boiler tube. Removal of the heat transfer fins from the boiler tube has, before the present invention, been done with portable power tools such as a grinding tool having a rotary abrasive wheel or with air chisels. These techniques are at best time consuming.
[0004] In addition, after removal of the damaged section of boiler tube, it may be necessary to remove heat transfer fins at or near the end of the remaining tube ends and to prepare the tube ends for welding to a new section of boiler tube. Proper preparation of the exposed tube ends requires beveling of the exposed tube ends for a good weld. More specifically, the exposed tube ends should have a frustoconical bevel to facilitate a good weld. It is highly desirable that this be done as quickly as possible.
[0005] It is, therefor, an object of the present invention to remove heat transfer fins from boiler tubes, more quickly and efficiently, and at the same time to bevel the exposed tube ends.
SUMMARY OF THE INVENTION
[0006] The present invention is a system for breaking or cutting the bonds holding a heat transfer fin base to a boiler tube and for concurrently beveling the exposed end of the boiler tube. It includes a first rotary milling head that has a cutting tip that traverses a circular path slightly larger than the outer diameter of the boiler tube. The cutting tip extends between adjacent windings of the heat transfer fin base. As the first rotary milling head is rotated, the cutting tip cuts or breaks the bonds of the heat transfer fin base by exerting forces both in the direction of rotation of the first rotary milling head and in the direction toward the first rotary milling head. It also includes a second rotary milling head that bevel the exposed end of the boiler tube. The rotary milling heads are guided and stabilized by a mandrel that fits on the inside of the boiler tube.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features and advantages of the present invention will be better understood by reading the following detailed description, taken together with the drawings wherein preferred embodiments as shown as follows:
[0008] FIG. 1 is a schematic diagram of a heat transfer base as it is wound around a boiler tube.
[0009] FIG. 2 is a schematic diagram of the first rotary milling head of the present invention.
[0010] FIG. 3 is a diagram of another view of the first rotary milling head of the present invention.
[0011] FIG. 4 is a diagram of the first rotary milling head of the present invention with a pneumatic means of rotation.
[0012] FIG. 5 is a diagram of the first rotary milling head of the present invention with a manual means of rotation.
[0013] FIG. 6 is a schematic diagram of the second rotary milling head of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] FIG. 1 shows a boiler tube 2 with inner diameter 3 , an outer diameter 4 and a circumference 5 . Heat transfer fins 6 are attached to a heat transfer fin base 7 that is wound around the tube 2 in a corkscrew fashion. The base 7 is then bonded to the boiler tube, typically by brazing or welding. Thus, one winding 8 of the base 7 is adjacent to another winding 9 of the base 7 .
[0015] The present invention includes a system for removing the heat transfer fins from the boiler tube 2 by cutting or breaking the bonds holding the heat transfer fin base 7 to the boiler tube 2 . As shown in FIG. 2 and 3 , a preferred embodiment of the first rotary milling head 30 of the present invention includes a first milling head base 32 rotatable around a center of rotation 33 extending through a first side 34 and a second side 35 with the first side 34 adapted to be connected to a second rotary milling head described below. This embodiment has three holes 37 extending through the first side 34 and the second side 35 to allow it to be attached to the second rotary milling head.
[0016] A cutting tool 40 has a cutting end 41 and a mounting end 42 with the mounting end 42 attached to the second side 35 of the first milling head base 32 . The cutting end 41 of the cutting tool 40 is attached to a cutting tip 43 that comprises an upper cutting surface 44 and a lower cutting surface 45 that intersect at a cutting angle 46 . The cutting tip 43 is oriented to move in the direction of rotation of the first milling head base 32 .
[0017] The mounting end 42 of the cutting tool 40 is attached to the second side 35 of the first milling head base 32 a distance from the center of rotation 33 of the first milling head base 32 such that the cutting tip 43 traverse a circular path whose diameter 47 is slightly larger than the outside diameter 4 of a boiler tube 2 when the first milling head base 32 is rotated. The first milling head base 32 also has a hole 49 of diameter 47 , which is slightly larger than the outside diameter 4 of a boiler tube 2 , extending through the first milling head base 32 from the first side 34 through the second side 35 . It is to be understood that both the means for attaching mounting end 42 of the cutting tool 40 to the second side 35 of the first milling head base 32 and the means for attaching the cutting end 41 of the cutting tool 40 to the cutting tip 43 include manufacturing cutting tip 43 , the cutting tool 40 , and the first milling head base 32 out of one piece of metal, as well as other means known to those skilled in the art.
[0018] Also, as shown in FIGS. 2, 3 and 5 , in operation, another preferred embodiment of the present invention, has a cutting tip 43 that extends between adjacent windings 8 , 9 of the heat transfer fin base 7 . The bond of the base 7 to the boiler tube 2 in one of the windings 8 , 9 is cut or broken by forces exerted by the cutting tip 43 both in the direction of rotation of the first milling head base 32 and in the direction toward the first milling head base 32 as the cutting tool 40 is rotated around the boiler tube 2 . In this preferred embodiment, the cutting angle 46 formed by the upper cutting surface 44 and the lower cutting surface 45 of the cutting tip 43 is chosen based on the spacing of the rows 8 , 9 of the heat transfer fin base 7 . The cutting tip 43 may be constructed of S 7 steel or other steels known to those skilled in the art.
[0019] Further, as shown in FIG. 5 , in operation, the cutting tool 40 is rotated around the boiler tube 2 and the cutting tip 43 breaks or cuts the bond of the heat transfer fin base 7 to the boiler tube 2 . The cutting tool 40 can be rotated manually as shown in FIG. 5 or through the use of other means of rotation, including an electric or pneumatic power tool. In another preferred embodiment of the present invention, the cutting angle 46 is such that it causes the cutting tip 43 to advance or self-feed as the cutting tool 40 is rotated around the boiler tube 2 . In another embodiment, gravity may be utilized to cause such an advance.
[0020] In another embodiment of the present invention, as shown in FIG. 4 , a power tool 10 is used to rotate the rotary milling head 30 . The power tool 10 also has a means to guide and stabilize the first rotary milling head 30 , which in this embodiment is a mandrel 14 , but which may be other means known to those skilled in the art. The mandrel 14 fits on the inside of the boiler tube 2 to guide and stabilize the first rotary milling head 30 during operation. The mandrel 14 has three clamp fingers 16 to lock against the inner diameter 3 of the boiler tube. The clamp fingers 16 are extended by turning the nut 18 on an extension of the mandrel 20 extending out of the back of the power tool 10 . In yet another embodiment of the present invention, the cutting tip 43 can be advanced by a feed mechanism, not here shown but known to those skilled in the art, on the extension of the mandrel 20 .
[0021] A second rotary milling head 100 of one embodiment of the present invention is shown in FIG. 6 . The second rotary milling head has a first side 110 and a second side 111 and is used to form a frustoconical bevel on the end of the tube 2 . The second rotary milling head 100 has a plurality of openings 101 on the second side 111 to receive cutting blades 102 . Each cutting blade 102 has a securing portion 103 that fits into opening 101 and is secured therein by securing element 104 . The first side 110 of the second rotary milling head 100 is mounted coaxially with the mandrel 14 to the output shaft of the power tool 10 . There are a number of different methods known to those skilled in the art for mounting the first side 110 of the second rotary milling head to 100 to the output shaft of the power tool 10 , including tool chucks.
[0022] In this embodiment, the first side 34 of the first rotary milling head 12 is then attached to the second side 111 of the second rotary milling head 100 by any one of a number of means known to those skilled in the art including using bolts from the second rotary milling head extending through the holes 37 in the first rotary milling head 12 so that the tube 2 extends through the hole 49 in the first milling head base 32 . While the first rotary milling head 12 is removing the heat transfer fin 6 , the second rotary milling head 100 is concurrently beveling the end of tube 2 . The desired length of fin removal is determined by the length of the first cutting head 12 .
[0023] The cutting blades 102 in the second rotary milling head 100 have cutting edges 105 that are angled at an approximate angle for producing the desired frustoconical bevel on the end of tube 2 . The first rotary milling head 12 and second rotary milling head 100 are advanced or retracted by the feed mechanism of the present invention.
[0024] While the principles of the invention have been described herein, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation as to the scope of the invention. Other embodiments are contemplated within the scope of the present invention in addition to the exemplary embodiments shown and described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention, which is not to be limited except by the following claims.
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A system is disclosed to use a first rotary milling head to break or cut the bond of a heat transfer fin base to a boiler tube, thereby removing the heat transfer fins from the boiler tube, and a second rotary milling head to bevel the exposed end of the boiler tube, thereby facilitating the more efficient repair of the boiler tube.
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RELATED APPLICATIONS
[0001] This application claims the benefit of 60/686,508, filed May 31, 2005, which application is fully incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a graphical user interface that assists a user in viewing, navigating and using online documents, and more particularly to a graphical user interface that is represented as an online line guide or copyholder, a graphical frame displayed around the active text of the document.
[0004] 2. Description of the Related Art
[0005] The continued growth of online documentation and applications for performing daily tasks has led to the need for an easier user interface for navigating and using these documents. In today's environment, people are less likely to use hard copies of documents to get their work done; documents are primarily available to users online. By way of example, and without limitation, in the area of procedure management, company procedures and processes which define the set of steps or instructions that must be followed to accomplish a task may be available to users online. The ability for a user to see what step of the procedure they are working on, to take action on a step of a procedure and to have the last step worked on recalled when a procedure document is suspended and reopened would be of great benefit to the user. Users need a better way to navigate and use online documents.
[0006] There is a need for a user interface that guides a user through use of online documents. There is a need for a visual representation of a users' current location in a document. If a user closes a document that they are working on, there is a need to reopen the document at this last location worked on.
SUMMARY OF THE INVENTION
[0007] Accordingly, an object of the present invention is to provide an improved graphical user interface.
[0008] Another object of the present invention is to provide a graphical user interface that guides a user through the use of online documents.
[0009] Yet another object of the present invention is to provide a graphical user interface that provides a visual representation of a users' current location in a document.
[0010] A further object of the present invention is to provide a graphical user interface that enable a user to close a document it is working on and then reopen the document at this last location worked on.
[0011] These and other objects of the present invention are achieved in, a user interface for viewing, navigating and using online procedure documents. Each procedure document has a set of well defined steps that define procedure content. A copyholder is provided that is a sliding window. The copyholder surrounds a step in the procedure document. The step enclosed by the copyholder is an active step. A representation of the copyholder is a line guide that slides across document text and guides a user through the set of steps of the document. A toolbar is provided on the copyholder. The toolbar has toolbar icons that represent actions to be performed on the active step of the document. An auto advance feature of the copyholder advances the copyholder to a subsequent next step in the document. At least one navigation icon on the copyholder enables the user to drag and drop the copyholder to any step defined in the document.
[0012] In another embodiment of the present invention, a user interface for viewing and navigating an online document that includes sections has a copyholder that is a sliding window. The copyholder surrounds a section of the document. The surrounded section is an active section. A representation of the copyholder is a line guide that slides across text of the online document and guides a user through the sections of the online document. The copyholder includes an auto advance that provides advancement to a next section in the document. The copyholder has navigation icons that permit the user to drag and drop the copyholder to any section in the document. A toolbar on the copyholder has toolbar icons that represent actions to be performed on the active section of the document.
[0013] In another embodiment of the present invention, a method is provided for navigating and using online procedure documents that include a set of well defined steps which define procedure content of a procedure document. A copyholder that is a sliding window is used to surround a step in the procedure document. A representation of the copyholder is sued as a line guide to slide across text of the procedure document and guide a user through the set of steps of the procedure document. A toolbar on the copyholder is used that includes toolbar icons representing actions to be performed on the active step of the procedure document. The copyholder is advanced to a subsequent next step in the procedure document. At least one navigation icon is sued on the copyholder to drag and drop the copyholder to any step defined in the procedure document.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is one representation of a copyholder interface.
[0015] FIG. 2 is a representation of a copyholder interface with navigation capability.
[0016] FIG. 3 is another representation of a copyholder with navigation displayed as a handle on the copyholder.
[0017] FIG. 4 is a representation of a copyholder interface with actions on the toolbar.
[0018] FIG. 5 is one representation of an opaque copyholder.
[0019] FIG. 6 is a representation of a collapsed copyholder. Navigation and action capabilities are provided.
[0020] FIG. 7 displays an expanded copyholder; the length of the copyholder is calculated based on the size of the active step in a document.
[0021] FIG. 8 is a representation of a docked view of the copyholder.
[0022] FIG. 9 is a representation of a docked view of a copyholder with action and navigation capability.
[0023] FIG. 10 is a representation of a copyholder with the ability to switch to a docked view.
[0024] FIG. 11 is a representation of a copyholder with step actions.
[0025] FIG. 12 displays the auto advance capability of a copyholder once a step is marked as completed.
DETAILED DESCRIPTION
[0026] In one embodiment of the present invention, a graphical user interface is provided that guides a user through the use of online documents. In one embodiment, if a user closes a document that it is working on, the graphical user interface permits a reopening of the document at this last location worked on. A line guide that highlights the users' current location in a document; remembers this location if the document is closed and enables document specific actions to be performed on the text at this location is needed. In one embodiment, the present invention defines a user interface that enables users to use online documents and permits the user to be interactively guided through using these documents and enables the user to suspend its work knowing that the line guide will remember where the user left off when the user reopens its document.
[0027] In one specific embodiment, the graphical user interface of the present invention is utilized in the area of procedure management. Each procedure is defined to contain a set of steps needed to accomplish the procedure or process in a system.
[0028] In one embodiment of the present invention, a graphical interface is defined that assists a user in viewing, navigating and using a procedure management document. By way of illustration, and referring now to FIG. 1 , an example of this interface is displayed. The copyholder interface 10 appears as a sliding window on top of the document text. By way of example, and without limitation, the document text 11 can be plain or structured text. The text 11 that is within the frame of the copyholder is considered the active text. The copyholder looks like a framed window 10 that appears to slide on top of the document text. By way of example, and without limitation, the copyholder extends the width of the document page and seems like a line guide attached to the edge of the document. The copyholder tracks the current active location as it moves through the document. The underlying document will define the text 11 that displays inside the copyholder. Referring again to FIG.1 , a step of the procedure document is highlighted by the copyholder and the text of the step is the active text.
[0029] In another embodiment of the invention, the user interface of the copyholder is expanded to include a navigation capability. The copyholder can be moved around the document text. The copyholder is expanded to include a navigation ability to slide the copyholder across the document. By way of example, and without limitation, the navigation can be represented as navigation icons on the copyholder or as a navigation bar on the navigation window that appears to clip the copyholder to the document text. The copyholder looks as if it slides over the document text once navigation is selected and can be viewed as a line guide moving through the document. The underlying document page will implement the next and previous navigation points, the copyholder will move to the specific location in the document as defined for previous and next points. Referring now to FIG. 2 , by way of illustration and without limitation, scroll icons 21 have been added to the copyholder. In this specific example, each step of the illustrated document is considered a navigation point and the navigable window will be moved to the next or previous step each time the scroll up or down arrows are selected. The text inside the copyholder is the active text, while the rest of the document text is visible to the user of the document. By way of another example, and without limitation, navigation can also be achieved by selecting the copyholder and dragging it to a new location in the document. The copyholder will slide across the document and anchor to the closest navigation point once released. Referring again to FIG. 2 , by way of illustration, each step in the document is considered a navigation point. The navigable window will be moved to the step closest to where the copyholder was dropped.
[0030] Referring to FIG. 3 , another example of how the navigation can be represented on the copyholder is shown. In this example, the navigation bar looks like a handle or clip 31 on the copyholder. The user can drag this handle to a new location in the document, or select the navigation arrows on the handle to move the copyholder to the next navigation point as defined by the underlying document page. The copyholder will appear to slide over the document text to its new location.
[0031] In another embodiment of the present invention, the sliding navigable copyholder is expanded to include a toolbar. The toolbar defines a set of actions to be performed on the text within the copyholder. By way of illustration, in this example the navigable window can select the text of a single step in a document. The toolbar will define the actions that can be performed on the active step. By way of example, and without limitation, action 1 could be to mark the step as read or to add a note to the step. Referring now to FIG. 4 , the navigable window has been expanded to include a set of toolbar actions 41 . By way of example, and without limitation, the toolbar actions can be displayed as buttons 41 or links 42 . The actions defined in each of these action buttons 41 or links 42 will be performed on the text 43 that is displayed within the sliding navigable copyholder. The toolbar actions defined will be related to the underlying document text.
[0032] In each embodiment of the current invention, the copyholder is displayed as a frame that seems to slide on top of the document text. The copyholder can be represented to have either a solid or transparent border on the window frame. By way of example, and without limitation, if the border is defined as transparent any text that appears to be under the frame would be visible to the user. Referring now to FIG. 5 , an example of what a transparent copyholder would look like is displayed. In this specific example, the text of the first sentence in step 3 is visible through the frame 52 . By way of illustration, the frame of the copyholder is equivalent to a clear line guide that moves across the document.
[0033] In another embodiment of the current invention, the ability to collapse the copyholder is defined. The copyholder that surrounds the active text can be collapsed and displayed as a copyholder clip with the embedded toolbar actions. The collapsed copyholder looks as if it is attached to the edge of the document page. The slider clip will appear to slide up and down the edge of the document opposite the active text. Referring now to FIG. 6 , an example of a collapsed copyholder is displayed 61 . The ability to navigate the window to the previous or next navigation point 62 in the document and to select actions to be performed 63 on the active step is available. In this example, the window frame that surrounded the active text has been removed. The ability to expand the copyholder 64 and collapse it down, are provided. By way of example, and without limitation, this can be achieved by adding an icon to the copyholder toolbar to collapse or expand copyholder 64 . Referring again to FIG. 6 , in this example the collapsed copyholder has a right arrow icon that will expand the copyholder to full size 64 .
[0034] In each embodiment of the current invention, the navigable sliding window will resize to enable the text of the current step to be viewed. By way of example, and without limitation, the step is defined by the underlying document text and could be a step within a document or a paragraph within a document. The underlying document will determine the height of the next component to be selected as active text and the copyholder will resize to enable display of this component. Referring now to FIG. 7 , an example of a larger active step is displayed 71 . By way of illustration, in this specific example, the height of the copyholder is calculated to enable the text of this step to display within the copyholder 71 .
[0035] In yet another embodiment of the invention, the copyholder is presented to the user in a workspace that is isolated from the user's desktop. In this embodiment, the copyholder will appear as a fixed window on the user's screen, and the text of the document will appear to scroll through the fixed copyholder. By way of illustration, this can be viewed as equivalent to a user pulling a document through a document holder. By way of example, and without limitation, a portion of the user's screen can be reserved to display the copyholder and make it appear to the user that it is docked here. The user can define where on their desktop they want to dock the window. By way of example, and without limitation, this could be the top, bottom or side of their screen. In this embodiment, a workspace is created on the user's screen that is isolated from the rest of the user's desktop. The workspace remains visible on the user's screen to provide for the user to see the location in the document that is currently active. The text that is within the docked copyholder is the active text; no other text of the document is visible on the user's screen. In this embodiment of the invention, the docked copyholder is defined as a fixed size. The underlying document will scroll through this fixed copyholder when the navigation arrows on the window are selected. The amount of text that scrolls is dependent on the underlying document and how the next and previous navigation points are defined.
[0036] Referring now to FIG. 8 , an example of a docked view of the copyholder is displayed. The copyholder appears docked at the top of the user's desktop 81 —the rest of the desktop 82 is available to the user to run other applications. The copyholder will not be overwritten with data from any other applications and will appear always at the location defined on the user's screen for the docked copyholder view.
[0037] In another embodiment of the current invention, the ability to expand the docked copyholder to include a toolbar of actions is defined. Similar to what was defined with the sliding copyholder, this toolbar can define actions to be performed on the text within the window. As illustrated in FIG. 9 , the docked window toolbar defines a set of actions 92 that can be applied to the text in the docked copyholder. By way of example, and without limitation, this could be the ability to mark the outcome of the active step or to add comments to the step.
[0038] In another embodiment of the current invention, the ability to switch between the sliding copyholder and the docked copyholder is defined. By way of example, this can be achieved by a link on the sliding copyholder which will switch to a docked view, and conversely by a link on the docked view which will switch back to the sliding navigable view. Users can determine which copyholder user interface works best for viewing and navigating through their document. They can switch between the two modes by selecting the appropriate link on the copyholder. Referring again to FIG. 9 , an example of what the docked view 91 with a link 93 to the sliding navigable window may look like is displayed. By way of illustration, and without limitation, a link to switch to a full page view is added to the toolbar 93 . By selecting this link or the arrow displayed next to it, the user's copyholder view will switch from docked mode back to the full mode display of the sliding copyholder. Referring now to FIG. 10 , an example of the full mode display of the sliding copyholder is shown 100 . By way of illustration, and without limitation, this example shows an arrow on the toolbar 101 that will switch the user back to the docked mode.
[0039] As indicated previously, the copyholder will advance through each navigation stop within a document. By way of illustration, in a procedure management document each step would be considered a navigation stop. The copyholder will initially display at the first step of a document when it is initially opened. The first step will be determined by the underlying document text. By way of example, and referring now to FIG. 11 , in a procedure document this would be the first step of the procedure 110 . The copyholder will automatically advance to the next step in a document if a step completion action is selected from the action toolbar. By way of example, this could be to mark the step as completed 111 , skipped 111 or stalled 111 . Referring now to FIG.12 , the copyholder has advanced to the next step in the procedure document 120 . The underlying system will implement methods to remember the current step in a document. If the document is closed and later reopened, the copyholder will initialize to correct step and scroll text on the page if necessary.
[0040] While the above is a description of the preferred embodiments of the invention, various alternatives, substitutions and modifications may be made without departing from the scope thereof, which is defined by the following claims. Thus, the preferred embodiments should not be taken as limiting the scope of the invention. Furthermore, the present invention is directed to a number of separate inventions and each of these inventions may be claimed independently of one another. Each feature, aspect and advantage of the invention may be claimed independent of one another without departing from the scope of the invention. Thus, the invention does not include a single essential feature, aspect or advantage and the invention should not be limited as such. It is intended, therefore, that the invention be defined by the scope of the claims which follow and that such claims be interpreted as broadly as is reasonable.
[0041] While the invention will be described in conjunction with a procedure management application, it is understood that it is not intended to limit the invention to this one application. To the contrary, it is intended to cover alternatives, modifications and equivalents as may be included within the scope of the invention as defined by the appended claims. It will be apparent to one skilled in the art that the implementation of such a user interface can be achieved in a variety of ways.
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A user interface is provided that enables a user to view, navigate and perform actions on an online document. The user interface is represented as a sliding window which appears to move smoothly across the document text. The sliding window, from herein referred to as the copyholder, moves across the document to locations in the document text that are defined by the underlying document. The copyholder size is determined by the underlying document, it can expand the width of the document text and the length of an active section or it can appear as a clip attached to the edge of the document. The copyholder contains an action bar with icons representing actions that can be performed on the document text. The current location of the copyholder in a document is saved when the document is closed. The copyholder will move to the saved location in the document text when the document is resumed and display the copyholder around the active document text.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/295,221 filed on Jan. 15, 2010, and of allowed U.S. patent application Ser. No. 13/006,672 filed on Jan. 14, 2011, both entitled “Valves,” the contents of both of which are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to valves and more particularly, although not necessarily exclusively, to check valves designed to accommodate fluids having, e.g., low pH or high salt content.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 6,247,489 to Maskell, et al., discloses an exemplary check valve especially useful as part of the water-recirculation system of a swimming pool, spa, or hot tub. The check valve includes a housing and a cover removably attached thereto. The housing may include coupling portions defining ports through which fluid may enter and exit the housing.
Pivotally attached to the cover of the check valve of the Maskell patent is a flapper assembly. The flapper assembly may comprise a diverter member having a body and two attachment arms. Pins are inserted through bores in the arms and the cover to attach the diverter member of the flapper assembly to the cover.
A spring (or other biasing member) may be positioned between the cover and the flapper assembly of the valve of the Maskell patent. The spring functions to bias the flapper assembly “into sealing engagement” with seats associated with the housing. Hence, when fluid flows through a conduit and into the entry port of the valve,
it contacts the flapper assembly and pivots it to an open position . . . wherein fluid is permitted to enter the central area of the valve and exit through the [exit] port. However, should the fluid . . . be discontinued or otherwise attempt to flow out from the central area through the [entry] port, the flapper assembly is pivoted by virtue of contact with such fluid and by the biasing force of the spring [which] serves to bias [the flapper assembly] into contact with the seat to achieve a fluid-tight seal therebetween.
The contents of the Maskell patent are incorporated herein in their entirety by this reference.
SUMMARY OF THE INVENTION
The check valve of the Maskell patent is a commercially useful product. However, when subjected to certain harsh environments, the valve may become less effective or fail sooner than desired. This is a particular risk when water flowing through the valve has low pH or high salt concentration, for example, as the water may cause pitting of the (typically stainless steel) biasing spring.
Accordingly, the present invention provides a check valve in which the biasing spring (which may be adjustable) is isolated from the flowing water. The valve may include a cover having a dry cavity in which the spring is positioned and a separate covering section for the cavity. Attachment arms of a diverter member (flapper) may receive a pivot pin to which a pivot link is pinned. Water-tight seals additionally may receive the pivot pin and prevent water from entering the cavity. Further, a bail may firmly receive ends of the pivot pin to facilitate transfer of motion of the flapper into extension of the spring.
The result is an assembly in which water flow against the (closed) flapper in one direction causes it to pivot against the bail (and thus to open), in turn causing rotation of the pivot pin. Rotation of the pivot pin, in its turn, causes rotation (or other movement) of the pivot link, which extends the biasing spring. Should the water flow cease (or reverse direction), the spring will tend to contract to its normal length and the flapper will return to its closed position. Alternatively, the assembly may be configured so that the flapper is normally open and closes as a function of water flow.
It thus is an optional, non-exclusive object of the present invention to provide a valve in which a biasing member is isolated from fluid flowing through the valve.
It is another optional, non-exclusive object of the present invention to provide a valve especially useful in certain harsh environments.
It is also an optional, non-exclusive object of the present invention to provide a check valve including a flapper configured to pivot about a pin.
It is a further optional, non-exclusive object of the present invention to provide a check valve in which a spring is positioned within a cover of the valve.
It is an additional optional, non-exclusive object of the present invention to provide a check valve in which a bail, attached to a pivot pin, facilitates transfer of motion of a flapper into extension or compression of a spring.
Other objects, features, and advantages of the present invention will be apparent to those skilled in the relevant art with reference to the remaining text and the drawings of this application.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective, partially-exploded view of portions of a check valve of the present invention.
FIG. 2 is a perspective view of portions of a first alternate version of the check valve of FIG. 1 .
FIGS. 3A-B are perspective views of portions of a second alternate version of the check valve of FIG. 1 .
DETAILED DESCRIPTION
Illustrated in FIG. 1 is cover 10 of an exemplary check valve of the present invention. Cover 10 may be similar to the covers described in the Maskell patent. Indeed, cover 10 may substitute for those covers if desired. In use, cover 10 is intended to be (removably) attached to a housing and, together with the housing, to form part of a valve assembly.
Cover 10 typically (although not necessarily) has generally circular cross-section with protrusions 14 extending outward about its periphery 18 . Consistent with the description in the Maskell patent, each protrusion 14 contains a bore 22 for receiving a screw or other fastener to attachment to the housing of the valve.
Again similar to the valve of the Maskell patent, that of the present invention may incorporate pin-receiving bores at or adjacent periphery 18 of cover 10 . Such bores receive pin 26 , connecting the pin 26 to cover 10 . Pin 26 preferably is cylindrical in central part 28 , albeit with D-shaped ends 30 . Pin 26 may, however, assume other shapes, as may its ends 30 . If ends 30 indeed are D-shaped, the flat portions of the “Ds” preferably face downward toward the housing when the valve is upright with cover 10 at its top.
Cover 10 may include cavity 34 in which (coil) spring 38 may be placed. A first end 42 of spring 38 may be anchored within cavity 34 in any suitable manner so that its second end 46 extends toward pin 26 . Rather than being connected directly to pin 26 outside cover 10 , however, second end 46 remains within cavity 34 and is connected to link 50 . Link 50 , in turn, is connected to central part 28 of pin 26 within cavity 34 . Annular (or other) seals 54 receive pin 26 to either side of link 50 , sealing boundaries of cavity 34 from fluid flowing through the valve.
Covering section 58 may function to cover cavity 34 to complete the isolation of spring 38 and link 50 . Section 58 preferably snap-fits onto cavity 34 to provide a generally continuous upper surface 62 of cover 10 . Section 58 may attach to cover 10 in other ways, however, if appropriate or desired.
Also illustrated in FIG. 1 is bail 66 , preferably (although not necessarily) made of plastic or other non-metallic material. Bail 66 may comprise elongated central portion 70 from which legs 74 A and 74 B extend. Each leg 74 A and 74 B may define a D-shaped bore 78 adapted snugly to receive a corresponding D-shaped end 30 of pin 26 .
Finally, depicted in FIG. 1 is flapper 82 , which may if desired be similar to the diverter member of the flapper assembly of the Maskell patent. Extending from flapper 82 are one or more arms 86 . In use, each arm 86 includes a bore 90 that receives pin 26 —preferably between a seal 54 and a leg 74 A or 74 B.
Flapper 82 typically is two-sided, with first side 94 shown in FIG. 1 . Fluid impinging sufficiently on first side 94 will tend to rotate flapper 82 (generally “into” the paper of FIG. 1 ) about pin 26 into an “open” position. This rotation itself may induce rotation of pin 26 depending on the amount of frictional contact between pin 26 and arms 86 . Otherwise, flapper 82 will rotate into contact with central portion 70 of bail 66 ; because of the keyed connection of D-shaped bores 78 and D-shaped ends 30 , such contact will cause bail 66 to induce rotation of pin 26 . In either circumstance (or via a combination of the two circumstances), rotation of pin 26 will cause movement of link 50 , which in turn will cause second end 46 to move away from first end 42 , hence extending spring 38 . Should the fluid impingement thereafter subside so as to be insufficient to overcome the contraction force of spring 38 , the spring 38 indeed will contract, moving link 50 and causing pin 26 to rotate in the opposite direction, and returning flapper 82 to the “closed” position illustrated in FIG. 1 . In the “closed” position, flapper 82 generally is seated (as described, for example, in the Maskell patent) so as to preclude further rotation (i.e. “out of” the paper of FIG. 1 ) and hence preclude any fluid impinging on the second side (not shown) of flapper 82 from exiting the valve via its entrance.
FIG. 2 illustrates cover 10 and spring 38 as part of a first alternate version of a check valve of the present invention. Second end 46 of spring 38 may be installed as shown in FIG. 1 . First end 42 , however, may be moveable within cavity 34 so as to adjust the bias provided by spring 38 . One such movement means is depicted in FIG. 2 : As shown, first end 42 connects to anchor 100 , whose position within rack 104 may be changed. Manual movement of anchor 100 between recesses 108 A-C of rack 104 thus changes the normal (resting) length of spring 38 , thereby changing the bias it may provide. Those skilled in the art will, of course, recognize that mechanisms other than as shown in FIG. 2 may be employed to effect changes in bias.
FIG. 3B illustrates cover 10 as well as anchor 100 , rack 104 , and recesses 108 A-C. Spring 38 ′ of FIGS. 3A-B is not an extension spring such as spring 38 , however. Instead, spring 38 ′ may be a compression spring. In this second alternate version of a check valve, the assembly may be reconfigured so that flapper 82 is normally open and designed to close as a consequence of sufficient fluid flow.
The assembly of the present invention thus provides a valve structure in which a biasing member, such as spring 38 or 38 ′, is isolated from fluid flowing through the valve. Although part of presently-preferred versions of the invention, bail 66 is optional and may, in some cases, be omitted. The foregoing thus is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of the invention.
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Valves, and particularly check valves, are detailed. The valves may isolate a spring or other biasing member from flowing fluid so as to reduce the possibility of damage to the spring caused, for example, by chemicals contained in the fluid. In some versions of the valves, the spring may be positioned within a cavity of a cover sealed from the fluid.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to application and verb resource management in systems that use Remote Direct Memory Access (RDMA) protocol.
BACKGROUND OF THE INVENTION
[0002] Remote Direct Memory Access (RDMA) is a technique for efficient movement of data over high-speed transports. RDMA enables a computer to directly place information in another computer's memory with minimal demands on memory bus bandwidth and CPU processing overhead, while preserving memory protection semantics. It facilitates data movement via direct memory access by hardware, yielding faster transfers of data over a network while reducing host CPU overhead.
[0003] Different forms of RDMA are known and used (all of which are referred to herein as RDMA), such as but not limited to, VIA (Virtual Interface Architecture), InfiniBand, iWARP and RNIC. In simplistic terms, VIA specifies RDMA capabilities without specifying underlying transport. InfiniBand specifies an underlying transport and a physical layer. RDMA over TCP/IP (transport control protocol/Internet protocol) specifies an RDMA layer that interoperates over a standard TCP/IP transport layer. RDMA over TCP does not specify a physical layer; and works over Ethernet, wide area networks (WAN) or any other network where TCP/IP is used. RNIC is an RDMA-enabled NIC (Network Interface Controller). The RNIC provides support for the RDMA over TCP and can include a combination of TCP offload and RDMA functions in the same network adapter.
[0004] RDMA protocols allow a direct access to the application buffers. Hardware interfaces with software using so-called Work Queues (WQ). Work queues are created in pairs, called a Queue Pair (QP), one for send operations (Send Queue) and one for receive operations (Receive Queue). The send work queue (SWQ) holds instructions that cause data to be transferred between one consumer's memory and another consumer's memory, and the receive work queue (RWQ) holds instructions about where to place data that is received from another consumer. The consumer submits a work request, which a Work Queue Element (WQE) to be placed on the appropriate work queue. A channel adapter executes WQEs in the order that they were placed on the work queue.
[0005] The abovementioned queues are managed by a so-called verb layer. This layer is a software library residing in the consumer memory space, and providing different RDMA services, like post send and receive request.
[0006] Application (wherein the term application encompasses, but is not limited to, user and kernel space; the term “consumer” is also used to denote “application”) posts its buffers for RDMA NIC processing using PostSend/PostRecv verbs. Once the buffers are posted by an application, ownership of the buffers passes to the RDMA NIC. An application is prohibited from accessing the buffers after they have been posted for RDMA processing. Application buffers remain in RDMA NIC possession till RDMA NIC completes their processing (finishes sending the data posted in those buffers, or receives the data destined for those buffers). RDMA NIC provides a way for an application to query for completed requests, herein referred to as a PollCompletion verb.
[0007] The prior art has different approaches to the problem of managing application buffers posted via Work Requests (WR) and verb resources (WQs).
[0008] Once the RDMA NIC has completed processing the posted WR, the application buffers consumed by this request can be reused by an application and WQEs can be reused by the verb layer.
[0009] An application uses PollCompletion verb to query the next completed WR (if any), and given information provided by this verb, the application can manage the buffers consumed by this WR. The decisions how to manage the buffers and when to query for completion of posted requests depend upon the application.
[0010] Not every posted request requires report of its completion. It is up to the application to select requests requiring completion report, so-called signaled requests.
[0011] There are several completion-reporting mechanisms used in the prior art, two basic ones being described with reference to FIGS. 1A-2B .
[0012] Reference is now made to FIGS. 1A and 1B , which illustrate a Write-back Status Approach used in the prior art to report completion of a WR.
[0013] As shown in FIG. 1A , a PostSend verb uses a send queue element SQE 10 for a send WR, and a PostReceive verb uses a receive queue element RQE 12 for a receive WR. When a WR is completed, an indication of the WR completion is written in a status field 14 of the WQE (i.e., SQE 10 or RQE 12 ). A PollCompletion verb is used to query the status field 14 of the WQE to found out if the corresponding WR is completed. Update of the status field in the WQE not only indicates completion of the consumer WR, but also indicates that this WQE can be reused by the verb layer.
[0014] It is noted that the PostSend/PostRecv and PollCompletion verbs all operate on the same WQ structure. The same status field 14 of the WQE is used for management of the application layer and the verb layer resources.
[0015] As shown in FIG. 1B , the verb layer can reuse a particular WQE only after the application layer has been informed that the status field of that WQE is checked as completed.
[0016] The Write-back Status Approach for querying completed requests by the application assumes use of the same data structure for posting new requests, deallocation of completed WQEs, and query on completed requests. In this approach, the application manages its own and verb layer resources.
[0017] Reference is now made to FIGS. 2A and 2B , which illustrate a Completion Queue Approach used in the prior art to report completion of a WR. For example, protocols like InfiniBand and iWARP use a completion queue approach. This approach introduces a new term of completion queue (CQ), wherein each entry of such a queue describes a single signaled WR that has been completed.
[0018] When the channel adapter completes a WR, a Completion Queue Element (CQE) 16 is placed on the CQ. Each CQE 16 specifies all the information necessary for a work completion, and either contains that information directly or points to other structures, for example, the associated WQE, that contain the information. In this approach, the PollCompletion verb is used to query the CQE 16 to found out if a particular WQE is now available.
[0019] As shown in FIG. 2B , the verb layer can reuse a particular WQE only after the application layer has queried the CQE 16 and been informed that the corresponding WR is completed.
[0020] This method allows much more flexible mechanism for managing of application resources:
a. sharing of the same completion queue between different WQs b. use a different data structures to post requests, and poll for completions
[0023] A disadvantage of this approach is that the release of WQEs is done again upon poll for completion. This forces the application protocol from time to time to post signaled WQEs to the CQE 16 allow WQE deallocation, even if their completion is not important from the protocol perspective. Another disadvantage is that the WQ address space must be accessible by the PollCompletion verb, and the CQ and QP must reside in the same memory space. Another disadvantage is the need to synchronize between PollCompletion and PostSend execution. For example, since PostSend consumes WQEs and PollCompletion releases WQEs, the update of the total number of WQEs needs to be synchronized.
SUMMARY OF THE INVENTION
[0024] The present invention seeks to provide improved methods for application and verb resource management in systems that use RDMA protocol. As described hereinbelow, the present invention may decouple the verb resource management from the application management.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the appended drawings in which:
[0026] FIGS. 1A and 1B are simplified illustrations of a Write-back Status Approach used in the prior art to report completion of a WR;
[0027] FIGS. 2A and 2B are simplified illustrations of a Completion Queue Approach used in the prior art to report completion of a WR; and
[0028] FIGS. 3A and 3B are simplified illustrations of a method for application and verb resource management in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0029] Reference is now made to FIGS. 3A and 3B , which illustrate a method for application and verb resource management in accordance with an embodiment of the present invention. The present invention may be used in a system 100 that uses RDMA protocol, such as but not limited to, RNIC.
[0030] As shown in FIG. 3A , a PostSend verb may use a send queue element SQE 10 for a post send WR, and a PostReceive verb may use a receive queue element RQE 12 for a post receive WR. Each posted request may comprise two bits. One bit, called an application request bit 18 , may indicate an application request for completion notification. Another bit, called a verb request bit 20 , may indicate a verb request for completion notification.
[0031] When the RDMA completes processing the posted request, it may check both the application request bit 18 and the verb request bit 20 . If the application request bit 18 is set (e.g., equals a logical ‘1’), then the RDMA may add a CQE 16 to the corresponding completion queue, indicating that that particular WR is completed (as indicated by arrow 23 in FIG. 3A ). The application may query this CQE 16 using a PollCompletion verb to find out if the particular WR is completed. This verb may retrieve an available CQE without any additional processing of the WQ, and may provide the application with sufficient information to manage the application buffers.
[0032] If the verb request bit 20 is set (e.g., equals a logical ‘1’), then the RDMA may update the WQE status field 14 of the particular SQE 10 or RQE 12 , thereby indicating that the particular WQE has been completed (as indicated by arrows 25 in FIG. 3A ). When the verb layer is requested to post a new request, it may check the WQE status field 14 of a particular WQE to found if the particular WQE is completed and is thus available for further use.
[0033] The method of the present invention may thus decouple management of verb resources from the management of application resources, and may enable efficient and flexible management of both the application and verb resources.
[0034] As shown in FIG. 3B , the application layer may decide when and why it wants to get an indication that particular WR has been completed. In other words, the application may decide when it needs to query completion information by using a PollCompletion verb to find out if the particular WR is completed. The application may share a common completion queue between several WQs, to simplify application resource management. None of those application decisions has any influence on the verb resources management. This method permits WQ and CQ to be located in different address spaces, not necessarily accessible one from another.
[0035] Independently of the application layer, the verb layer may decide when and why it wants to get an indication that particular WQE has been completed, by checking the status field 14 in a particular WQE. The WQ and CQ do not necessarily have to be in the same memory space, and do not necessarily have to be accessible by common software components.
[0036] It is noted that the methods shown in FIGS. 3A and 3B and described hereinabove, may be carried out by a computer program product, such as but not limited to, Network Interface Card (NIC), Host Bus Adapter (HBA), a floppy disk, hard disk, optical disk, memory device and the like, which may include instructions for carrying out the methods described hereinabove.
[0037] The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
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A method for controlling access to computer memory, the method including communicating work queue elements with an application layer and with a verb layer, and indicating completion of the work queue elements, wherein both the application layer and the verb layer are capable of checking if at least one of the work queue elements is completed, independently of each other.
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CROSS-REFERENCE TO RELATED APPLICATIONS
None
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A MICROFICHE APPENDIX
Not applicable
BACKGROUND OF THE INVENTION
This invention relates to methods of efficiently applying low temperature heat to absorption refrigeration cycles and absorption power cycles. In conventional absorption cycles, high temperature heat is applied to a high-pressure desorber or generator, where high-pressure vapor is desorbed from the absorbent solution. When the resulting vapor is pure refrigerant, as with LiBr—H 2 O absorption cycles, no further treatment is necessary. When the resulting vapor has appreciable absorbent content, as with NH 3 —H 2 O absorption cycles, it is necessary to distill, analyze, or rectify the vapor to higher refrigerant purity by contacting it with lower temperature absorbent. That distillation may be done either adiabatically or diabatically. The external heat addition portion of the desorber is customarily termed the generator, and the distillation portion may have internal heat addition.
When the external heat source is at relatively low temperature, for example only modestly above the generator temperature, and when it has a temperature glide, then very little of the heat content of the source can be effectively transferred to the generator using conventional techniques. Consider for example a combustion exhaust stream at 270° C., and an absorption cycle generator at 170° C. Given a 30° C. minimum temperature difference for heat transfer, it is only possible to cool the heat source from 270° C. to 200° C. by transferring heat to the generator. This is only on the order of 30% of the available heat content of that source.
Two other possible problems arise when supplying low temperature waste heat such as combustion exhaust gas to an absorption cycle. With one approach, the combustion exhaust directly contacts the heat transfer surface of the generator. However, there are usually stringent limitations on the allowable pressure drop of the exhaust gas. For example, the backpressure for a combustion turbine is typically specified at no more than six to ten inches water column. The generator which satisfies both this criterion and also the specialized mass transfer criteria of the absorbent solution will be very large and costly. That is, the transfer geometry necessary for effective desorption is very different from that necessary for low Δp extraction of heat from combustion gas. Alternatively a closed cycle heat transfer fluid can be circulated between the heat source and the generator, such that the geometry of each heat exchanger is free to be optimized for the respective requirements. This has the disadvantage that two separate heat exchanger temperature differentials are interposed between the waste heat and the absorbent solution in the generator. For example, the heat transfer fluid must be heated to well above the generator peak temperature. If water is the heat transfer fluid, it will have to be at a much higher pressure than the generator.
There are a variety of hydrocarbon-fueled prime movers which exhaust a combustion gas, including gas turbines, microturbines, reciprocating engines, and fuel cells. Depending upon the prime mover, the exhaust temperature varies from 200° C. to 550° C. There is increasing need and desire to convert that exhaust heat to useful purpose, such as cooling, refrigeration, shaft power, or electricity. It is one objective of the present invention to convert greater fractions of waste heat to useful purpose than has heretofore been possible. It is another objective to avoid the prior art disadvantages of applying waste heat to absorption cycles, i.e., the high backpressure associated with direct contact heat transfer, and the high temperature differentials associated with pump-around loops. That is, there is a need for a method of transferring heat from a low temperature sensible heat source to an absorption cycle which avoids the Δp and ΔT and high pressure penalties associated with traditional methods, while achieving greater utilization of the heat source, i.e., more useful result.
BRIEF SUMMARY OF THE INVENTION
The above and other useful objects are achieved by apparatus wherein thermal energy is converted into at least one of refrigeration, cooling, and shaft power comprising:
a) an absorbent solution comprised of sorbate plus absorbent;
b) a desorber comprised of:
i) an entry port for sorbate-rich liquid absorbent;
ii) a means for separating said sorbate-rich absorbent into sorbate vapor and sorbate-lean absorbent;
iii) an exit port for said sorbate vapor; and
iv) an internal heat exchanger which has an entry port in communication with said sorbate-lean absorbent;
c) an external heat exchanger which is in thermal contact with said thermal energy;
d) a first flowpath from an exit port of said internal heat exchanger to said external heat exchanger; and
e) a second flowpath from said external heat exchanger to said desorber;
and also by process comprising:
a) circulating an absorbent solution successively through absorbing and desorbing steps;
b) desorbing the absorbent solution into high-pressure sorbate vapor and heated strong absorbent by heating it;
c) using the heated strong absorbent as the heating agent in step b);
d) reheating said heating agent by thermally contacting it with said thermal energy; and
e) combining said reheated heating agent with said heated strong absorbent.
The greater utilization of the thermal energy in the waste heat or other low temperature heat source is accomplished by applying it to a heat transfer agent, and then applying the heat transfer agent heat to at least part of a distillation step, (when present) which is at lower temperature, and/or by applying it to an intermediate-pressure desorber which is at lower temperature. Either or both of these steps further reduce the heat transfer agent temperature to below the high-pressure generator temperature, and in turn make it possible to reclaim lower temperature heat from the heat source. With this technique, the heat transfer agent can be routinely cooled to approximately 80° C. or lower, which means the combustion gas can be cooled to approximately 100° C. or lower.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 depicts one embodiment of the integrated heating system constituent parts and their arrangement.
FIG. 2 depicts a two-pressure single-effect absorption cycle with co-current mass exchangers which produces cooling from low temperature waste heat using the integrated heating system.
FIG. 3 depicts a three-pressure absorption cycle for a volatile absorbent such as NH 3 —H 2 O which is adapted to produce shaft power from waste heat using an integrated heating system.
FIG. 4 depicts a two-pressure absorption cycle adapted to produce both power and cooling from combustion turbine exhaust via an integrated heating system.
FIG. 5 depicts a three-pressure absorption refrigeration cycle powered by low temperature heat via an integrated heating system.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a low temperature sensible heat stream such as combustion exhaust gas is supplied to heat reclaimer 1 through inlet 2 , where it contacts the external heat exchanger 3 . Pump 4 circulates a heat transfer fluid through heat exchanger 3 , in direction overall counter-current to the flow direction of the exhaust gas. By having the heat reclaimer 1 vertically oriented as shown, any condensate formed on the cooler bottom coils drains away, and also the coils can be adapted to be self-draining should pump 4 fail, thus preventing over-pressurization. The heated heat transfer fluid exits reclaimer 1 preferably as a two-phase mixture and is routed to desorber 5 , where phase separation occurs. The resulting liquid phase comprised of both liquid from the reclaimer and also sorbate-lean absorbent solution (i.e. “weak” absorbent) from the remainder of the desorber, is routed through pipe 6 into internal heat exchanger 7 which supplies heat to colder portions of the desorber, for example, by means of a succession of vertically stacked diabatic trays 49 . The hot vapor also traverses up through the desorber, on the other side of internal heat exchanger 7 . The purified vapor exits the generator through pipe 8 and is routed to the remainder portion of the absorption cycle 9 . The heat transfer fluid exits the internal heat exchanger 7 and desorber 5 through pipe 10 , and is split at splitter 12 , with part going via pressure letdown valve 13 to the absorption step in portion 9 , and the remainder to pump 4 for recycle to reclaimer 1 . The high-pressure vapor from pipe 8 is converted in portion 9 to a low-pressure vapor, via a condenser and evaporator so as to produce cooling, and/or via a work expander to produce shaft power. The resulting low-pressure vapor and absorbent from pipe 10 are subsequently recombined in portion 9 and pumped back to the entry port for sorbate-rich absorbent of desorber 5 via pipe 11 . The heat exchanger in reclaimer 1 can be comprised of concentric tube coils, pancake tube coils, or any other known geometry, e.g., fin tubes, folded plates, or others such as those used for steam cycle economizers. Particularly pertinent are the steaming type of economizers which ordinarily produce a two-phase mixture. With ammonia-water cycles, the heat transfer fluid will usually be nearly pure water, and the pressure will be essentially the generator pressure, since the two fluids combine at the generator. With LiBr—H 2 O absorption cycles, the circulating heat transfer fluid will be concentrated LiBr solution.
By integrating the heat transfer fluid directly into the absorption cycle, the advantage is retained that the reclaimer can be optimized for the necessary low pressure drop, and yet there is no additional temperature differential penalty because the heating fluid temperature never increases to appreciably above the hottest generator temperature. Since most of the heating duty in the heat reclaimer is sensible heating of the heating agent, the temperature difference between the heating agent and the combustion exhaust can be relatively constant, resulting in highly efficient heat exchange, i.e., avoiding the pinch temperature associated with constant temperature boilers.
In FIG. 2 and succeeding figures, objects with similar descriptions are afforded the same number in each sequence, e.g., object 201 of FIG. 2 is described similarly as object 101 of FIG. 1 .
Referring to FIG. 2, low temperature sensible heat is supplied to heat reclaimer 201 via entry port 202 . Pump 204 circulates heat transfer agent through reclaimer 201 counter-currently to the exhaust flow direction. Two-phase heat transfer agent is then routed to the hot end of generator 205 (also called a desorber). Vapor is withdrawn via pipe 208 , and hot liquid is supplied to an internal heat exchanger in generator 205 via pipe 206 . That liquid exits at pipe 210 , is split at splitter 212 , with part being recycled via pump 204 , and the remainder supplied to low-pressure absorber 217 via pressure letdown valve 213 . High-pressure vapor in pipe 208 is condensed in condenser 214 , subcooled in subcooler 215 , reduced in pressure in pressure letdown 219 , and evaporated in evaporator 216 . The resulting low-pressure vapor is absorber into sorbate-lean (“strong”) absorbent 217 , which is cooled by coolant 220 , and the resulting sorbate-rich (“weak”) absorbent is pumped by pump 218 back to desorber 205 . The various exchanges may be shell and tube, coil in shell, or other known types.
Referring to FIG. 3, waste heat enters reclaimer 301 through entry port 302 . Heat transfer fluid is counter-currently circulated through steaming economizer 303 via pump 304 , and thence to the bottom of desorber column 305 , where phase separation occurs. The liquid phase enters internal heating coils 307 via inlet pipe 306 . Part of the IIliquid phase is split off at splitter 312 and routed to pressure letdown 313 via solution heat exchanger 326 . The remainder heats the colder top end of column 305 , then supplies lower temperature heat to intermediate pressure desorber 323 , and then is recycled by pump 304 . Desorber vapor in pipe 308 is superheated in superheater 321 by counter-current heat exchange with the source heat, in parallel with exchanger 303 . Then the superheated vapor is work-expanded in expander 322 . The resulting low-pressure vapor is absorbed in low-pressure absorber 317 into the strong absorbent from letdown 313 , while absorption heat is removed
By integrating the heat transfer fluid directly into the absorption cycle, the advantage is retained that the reclaimer can be optimized for the necessary low pressure drop, and yet there is no additional temperature differential penalty because the heating fluid temperature never increases to appreciably above the hottest generator temperature. Since most of the heating duty in the heat reclaimer is sensible heating of the heating agent, the temperature difference between the heating agent and the combustion exhaust can be relatively constant, resulting in highly efficient heat exchange, i.e., avoiding the pinch temperature associated with constant temperature boilers.
In FIG. 2 and succeeding figures, objects with similar descriptions are afforded the same number in each sequence, e.g., object 201 of FIG. 2 is described similarly as object 101 of FIG. 1 .
Referring to FIG. 2, low temperature sensible heat is supplied to heat reclaimer 201 via entry port 202 . Pump 204 circulates heat transfer agent through reclaimer 201 counter-currently to the exhaust flow direction. Two-phase heat transfer agent is then routed to the hot end of generator 205 (also called a desorber). Vapor is withdrawn via pipe 208 , and hot liquid is supplied to an internal heat exchanger in generator 205 via pipe 206 . That liquid exits at pipe 210 , is split at splitter 212 , with part being recycled via pump 204 , and the remainder supplied to low-pressure absorber 217 via pressure letdown valve 213 . High-pressure vapor in pipe 208 is condensed in condenser 214 , subcooled in subcooler 215 , reduced in pressure in pressure letdown 219 , and evaporated in evaporator 216 . The resulting low-pressure vapor is absorber into sorbate-lean (“strong”) absorbent 217 , which is cooled by coolant 220 , and the resulting sorbate-rich (“weak”) absorbent is pumped by pump 218 back to desorber 205 . The various exchanges may be shell and tube, coil in shell, or other known types.
Referring to FIG. 3, waste heat enters reclaimer 301 through entry port 302 . Heat transfer fluid is counter-currently circulated through steaming economizer 303 via pump 304 , and thence to the bottom of desorber column 305 , where phase separation occurs. The liquid phase enters internal heating coils 307 via inlet pipe 306 . Part of the IIliquid phase is split off at splitter 312 and routed to pressure letdown 313 via solution heat exchanger 326 . The remainder heats the colder top end of column 305 , then supplies lower temperature heat to intermediate pressure desorber 323 , and then is recycled by pump 304 . Desorber vapor in pipe 308 is superheated in superheater 321 by counter-current heat exchange with the source heat, in parallel with exchanger 303 . Then the superheated vapor is work-expanded in expander 322 . The resulting low-pressure vapor is absorbed in low-pressure absorber 317 into the strong absorbent from letdown 313 , while absorption heat is removed by cooling heat transfer stream 320 . The resulting absorbent is pumped to intermediate-pressure in pump 318 , then split into a feed to intermediate-pressure desorber 323 and to intermediate-pressure absorber 324 . Vapor from intermediate-pressure desorber 323 is separated at separator 327 and then absorbed in intermediate-pressure absorber 324 . Pump 325 pumps the resulting weak absorbent back to high pressure for re-entry into column 307 . The FIG. 3 cycle incorporates both counter-current mass exchange columns ( 305 and 317 ) and co-current mass exchangers ( 323 and 324 ). Branch pump 328 improves the linearity of the temperature glide in column 307 .
Referring to FIG. 4, a two-pressure absorption cycle for a volatile absorbent such as aqua ammonia is depicted, adapted to be powered by combustion turbine waste heat, and further adapted to co-produce both shaft power and also refrigeration, for cooling the turbine inlet air or other cooling loads. Air compressor 451 is supplied air through filter 452 and cooling coil 453 . The compressed air supports combustion in combustor 454 , and the resulting hot pressurized combustion gas is work-expanded in turbine 455 . The combustion exhaust is ducted through exhaust duct 456 to optional heat recovery steam generator (HRSG) 457 , and thence to heat reclaiming section 401 , comprised of heating agent heater 403 , superheater 421 , and HRSG economizer 458 . The heating agent is supplied to the sump of column 405 where it phase separates. The liquid fraction enters internal exchanger 407 through entry port 406 , and part is split off at splitter 412 , and sent to letdown valve 413 , thence to low-pressure absorber column 417 . Low-pressure vapor from turbine 422 , evaporator 416 , and inlet cooler 453 is absorbed in low-pressure absorber 417 , with the colder portion of the heat of absorption removed by cooling stream 420 , and the warmer portion by high-pressure GAX (generator absorber heat eXchange) desorption coil 459 , from which the two-phase mixture is routed to a mid-height of column 405 . Part of the pumped weak absorbent from pump 418 is routed to GAX coil 459 , through split control valve 460 , and the remainder is routed through split controller 461 to solution-cooled rectifier 462 , and then sprayed into the top portion of column 405 . Pump 404 circulates the heating agent. The vapor split between turbine 422 and coolers 416 and 453 is controlled by valves 463 and 464 , respectively. As shown, those two vapors can be of differing purity, governed by the height of column 405 from which they are withdrawn. It is desirable to send quite high purity vapor to condenser 414 , for example at least 95% purity ammonia.
Referring to FIG. 5, low temperature heat supplied to reclaimer 501 heats heating agent in fin coils 503 . Then the two-phase heating agent is routed to the sump region of desorption column 505 , where the phases separate. The liquid phase enters entry port 506 of internal heat exchanger 507 , a succession of coils on vertically stacked vapor-liquid contact trays 549 . High-pressure vapor from column 505 is condensed in condenser 514 , subcooled in subcooler 515 , expanded in pressure letdown 519 , and evaporated in evaporator 516 , thus producing refrigeration and low-pressure vapor. That vapor is absorbed into the strong absorbent from splitter 512 and pressure letdown 513 , in low-pressure absorber column 517 . Column 517 has three sets of cooling coils, in top to bottom (hot to cold) order: High-pressure GAX desorption coil 559 (shown as occupying two trays 548 ); intermediate-pressure GAX desorption coil 547 , (shown as a occupying single tray 546 ); and the bottom coils for external cooling agent 520 , shown as occupying two trays 545 . The absorbent from low-pressure absorber 517 is pumped to intermediate-pressure by pump 518 , then split by valves 544 and 543 into feeds to an intermediate pressure GAX absorber 547 and the intermediate-pressure absorber 524 . The weak absorbent (water with high ammonia content) from intermediate-pressure absorber 524 is pumped to high pressure by pump 525 , and split into two streams by valves 542 and 541 ; the former stream being supplied sequentially to solution-cooled rectifier coil 540 and then to high-pressure GAX desorber coil 559 , and finally to column 505 as two-phase; and the latter directly injected into column 505 . Branch pump 528 supplies a mid-height of column 505 , thereby providing a more linear temperature glide in that column.
The three pressure cycles have similarity to prior art disclosures such as U.S. Pat. No. 5,097,676. The diabatic counter-current columns such as the desorber (distillation column) and low-pressure absorber (reverse distillation column) may be any known geometry. One preferred geometry is the diabatic multi-tray design with contact coils, such as disclosed in U.S. Pat. No. 5,798,086. Particularly preferred are those diabatic trays with same-direction liquid flow and minimal vapor mixing, as disclosed in International Publication No. WO 00/10696, dated Mar. 2, 2000.
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An absorption system powered by low temperature heat for producing at least one of refrigeration and power is disclosed, wherein a low-pressure drop heat reclaimer 1 reclaims heat from the source into a heating agent, which in turn supplies heat to the absorption cycle desorber 5 via internal coils 7. The extra temperature differential normally present in closed cycle heating systems is avoided by using the absorption working fluid as the heating agent, in an integrated system.
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[0001] In general, the present invention relates to firearms and particularly, the present invention relates to an adjustable rear iron sight for firearms including height adjustment compensation for projectile drop.
BACKGROUND OF THE INVENTION
[0002] Virtually all firearms are equipped with some type of sighting system to facilitate aiming the weapon. Examples of these sighting systems include telescopic sights, holographic sights, laser sights and iron sights. Iron sights also called open sights, consist of a front sight and a rear sight that the shooter aligns together onto the target he/she is aiming at. Iron sights can be either fixed or adjustable and made from iron or any other material
[0003] Adjustable iron sights allow for vertical adjustment called elevation and horizontal adjustment called windage. In use the sight is adjusted so that projectiles fired from the firearm will hit the target at the same point that is seen by aligning the sights to the target. This distance from the firearm to the target is known as the zero range. At distances in front of the zero range the projectile will hit the target above the line of sight and at distances beyond the zero range the projectile will hit the target below the line of sight, due of course the projectile drop caused by gravity and changes in velocity.
[0004] Typically firearms use an adjustable rear iron sight to compensate for projectile drop and these often use a fine adjustment screw for accurate adjustment. However the fine threads of the vertical adjustment screw often required multiple complete and partial turns to get to the correct setting, with the likelihood of making a mistake in counting that would result in an incorrect setting and also losing the initial zero range setting. Even when the sights have markings these are often difficult to read and generic, that is they require knowledge of the trajectory of the firearm/load combination in order to adjust the single elevation screw to the correct setting.
[0005] Some military iron sights from the prior art allow for projectile drop compensation but only for a standardized military load. The increments of elevation are also too large to be useful for hunting.
SUMMARY OF THE INVENTION
[0006] It is one object of the invention to provide an improved adjustable rear iron sight for a fire arm.
[0007] According to one aspect of the invention there is provided an adjustable rear iron sight for a firearm comprising:
[0008] a rear sighting element for mounting at a rear of the fire arm and defining a visible alignment portion for visual alignment by the user with a front sighting element;
[0009] a mounting member having mounting elements for attachment of the mounting member to the firearm;
[0010] an adjustable member carried on the mounting member and adjustably movable upwardly and downwardly relative thereto;
[0011] the sighting element being mounted on the adjustable member so that the upward and downward adjustment acts to change the height of the sighting element on the firearm so as to compensate for projectile drop over different distances;
[0012] a manually rotatable wheel mounted on the mounting member for manual rotation by the user about an axis of the wheel;
[0013] the wheel carrying a cam for rotation therewith having a generally spiral cam surface defining a spirally changing radius from the axis for engaging an abutment on the adjustable member and moving the adjustable member to a height determined by the radius at any selected position on the spiral cam surface;
[0014] the wheel having a plurality of distance markings on a visible surface thereof angularly spaced around the axis for selection by the user of a required distance marking by rotating the wheel to a selected angular position determined by selection of the required distance marking;
[0015] the spiral cam surface having a profile of radius changes calibrated such that the distance markings are each associated with a respective required height of the adjustable member.
[0016] Preferably there is provided with the mounting member, sighting element and adjustable member a plurality of wheels each having a cam with a different profile of the cam surface where the cam spiral cam surface of each wheel has a profile of radius changes calibrated relative to a different shot load for the fire arm.
[0017] Preferably the wheel is readily removable and replaceable for replacement with a second wheel having a cam with a different profile of the cam surface where the cam spiral cam surface of each wheel has a profile of radius changes calibrated relative to a different shot load.
[0018] Preferably the wheel is readily removable and replaceable for replacement with a second wheel having a cam with a different profile of the cam surface where the cam spiral cam surface of each wheel has a profile of radius changes calibrated relative to a different fire arm.
[0019] Preferably the wheel is attached to the mounting member by a single screw extending along the axis and defining a shaft for rotation of the wheel.
[0020] Preferably the rear sighting element is mounted on the adjustable member for side to side movement for adjustment of the rear sighting element to compensate for windage.
[0021] Preferably the rear sighting element is mounted on the adjustable member by an adjustment screw.
[0022] Preferably the adjustable member is mounted on the mounting member by a pair of upstanding pins allowing sliding movement of the adjustable member on the mounting member.
[0023] Preferably the pins carry springs for biasing the adjustable member onto the cam surface.
[0024] Preferably the wheel is mounted between the pins below the adjustable member and the springs bias the adjustable member downwardly onto the cam surface.
[0025] Preferably the wheel and the mounting member include cooperating elements for restraining the wheel in a plurality of angular positions corresponding to the distance markings on the wheel.
[0026] Preferably the cooperating elements comprise series of recesses in one of the mounting member or the wheel and a spring biased ball for engaging into the recesses and carried on the other of the mounting member or the wheel.
[0027] Preferably the mounting member comprises an upstanding block with a first upstanding side surface having the mounting elements for attachment of the mounting member to the firearm and a second parallel upstanding side surface carrying the wheel.
[0028] According to a second aspect of the invention there is provided an adjustable rear iron sight for use with different firearms having different available shot loads comprising:
[0029] a rear sighting element for mounting at a rear of the fire arm and defining a visible alignment portion for visual alignment by the user with a front sighting element;
[0030] a mounting member having mounting elements for attachment of the mounting member to the firearm;
[0031] an adjustable member carried on the mounting member and adjustably movable upwardly and downwardly relative thereto;
[0032] the sighting element being mounted on the adjustable member so that the upward and downward adjustment acts to change the height of the sighting element on the firearm so as to compensate for projectile drop over different distances;
[0033] and a plurality of manually rotatable wheels each arranged to be readily removably mounted on the mounting member;
[0034] each wheel being arranged, when mounted, for manual rotation by the user about an axis of the wheel;
[0035] each wheel carrying a cam for rotation therewith having a generally spiral cam surface defining a spirally changing radius from the axis for engaging an abutment on the adjustable member and moving the adjustable member to a height determined by the radius at any selected position on the spiral cam surface;
[0036] each wheel having a plurality of distance markings on a visible surface thereof angularly spaced around the axis for selection by the user of a required distance marking by rotating the wheel to a selected angular position determined by selection of the required distance marking;
[0037] each spiral cam surface having a profile of radius changes different from that of the other cam surfaces of the different wheels and calibrated such that the distance markings are each associated with a respective required height of the adjustable member relative to a different shot load for a selected fire arm.
[0038] According to a third aspect of the invention there is provided an adjustable rear iron sight for a firearm comprising:
[0039] a rear sighting element for mounting at a rear of the fire arm and defining a visible alignment portion for visual alignment by the user with a front sighting element;
[0040] an upstanding mounting block with a first upstanding side surface having mounting elements for attachment of the upstanding mounting block to the firearm and a second parallel upstanding side surface;
[0041] an adjustable member carried on a top of the upstanding mounting block and adjustably movable upwardly and downwardly relative thereto;
[0042] the sighting element being mounted on the adjustable member so that the upward and downward adjustment acts to change the height of the sighting element on the firearm so as to compensate for projectile drop over different distances;
[0043] a manually rotatable wheel mounted on the second side surface of the upstanding mounting block for manual rotation by the user about an axis of the wheel extending at right angles to the second side surface;
[0044] the wheel carrying a cam for rotation therewith having a generally spiral cam surface defining a spirally changing radius from the axis for engaging an abutment on the adjustable member and moving the adjustable member to a height determined by the radius at any selected position on the spiral cam surface;
[0045] the wheel having a plurality of distance markings on a visible surface thereof angularly spaced around the axis for selection by the user of a required distance marking by rotating the wheel to a selected angular position determined by selection of the required distance marking;
[0046] the wheel and the mounting member include cooperating elements for restraining the wheel in a plurality of angular positions corresponding to the distance markings on the wheel;
[0047] the spiral cam surface having a profile of radius changes calibrated such that the distance markings are each associated with a respective required height of the adjustable member.
[0048] The invention also provides a method of adjusting the rear iron sight of a firearm as described above in which the wheel is selected from a plurality of wheels each having a cam with a different profile of the cam surface where the cam spiral cam surface of each wheel has a profile of radius changes calibrated relative to a different shot load for a selected fire arm.
[0049] The adjustable rear sight described herein may have one or more of the following features:
[0050] allowance to adjust windage and elevation for a zero range;
[0051] projectile drop compensation to allow a “dead on” hold at any selected distance;
[0052] projectile drop compensation interchangeable to allow using non-standardized loads;
[0053] multi-position stops at useful distance intervals;
[0054] positive stops to prevent accidental movement;
[0055] easy to see markings indicating distance interval;
[0056] quick adjustment without needing to use tools.
[0057] To attain these features, the arrangement described hereinafter provides a sight mounting block which mounts the sight to said firearm, said sight mounting block containing mounting holes to allow attachment to said firearm, a threaded mounting hole to allow for attaching the projectile drop compensation mechanism, a spring and ball that apply force to maintain the position of the interchangeable multi-position cam and cavities being dimensioned to cooperate with the springs and modified shoulder bolts that control the vertical motion of the aperture mounting block; a projectile drop compensation mechanism which comprises a mounting shoulder screw and an interchangeable multi-position cam that raises the aperture mounting block via the vertical elevation screw, said cam profile to match the trajectory of the particular firearm and load; an aperture mounting block containing threaded holes for fastening the shoulder bolts that control its vertical motion, a vertical elevation screw, a horizontal windage screw, a threaded aperture block and an aperture.
[0058] To provide allowance to adjust windage, a horizontal windage screw is contained in the aperture mounting block. Turning the screw clockwise causes the aperture block and aperture to move to the right as a result moving the point of impact to the right and turning the screw counter-clockwise causes the aperture block and aperture to move to the left as a result moving the point of impact to the left
[0059] To provide allowance to adjust elevation for the zero range, a vertical elevation screw is contained in the aperture mounting block. The point of the vertical elevation screw rests on the profiled section of the interchangeable multi position cam. With the cam set to its lowest setting, adjusting elevation for the zero range can be performed. Turning the screw clockwise causes the aperture mounting block to raise (containing the aperture block and aperture) as a result moving the point of impact higher. Turning the screw counter-clockwise causes the aperture mounting block to lower (containing the aperture block and aperture) as a result moving the point of impact lower.
[0060] Projectile drop compensation is achieved by adjusting the interchangeable multi position cam to the desired distance setting that is the closest match to the distance from the target. The profiled section adds the necessary increase in elevation to the zero range due to its direct contact with the point of the vertical elevation screw. The profile which has been machined into the cam has been determined using ballistic data calculated from customer supplied load information and the spacing between the front and rear sight. If the customer wishes, additional interchangeable multi position cams can be purchased and the customer only needs to install the correct cam to be able to aim “dead on” at any distance selected between the minimum and maximum distance settings.
[0061] The front face of the interchangeable multi position cam displays distance settings in large easy to read numbers and lines. The distance intervals are close enough to allow the average point of impact to be will be within 1″ of the zero range at every setting. The circumference is knurled to provide ease of adjustment. Cam position is maintained by pressure of the spring loaded ball located in the sight mounting block engaging depressions in the rear surface of the cam.
[0062] Quick adjustments to the desired distance setting are ensured by fact that the sight is always ready to be adjusted. The precision fit of the parts controlling the linear vertical movement prevent any looseness that require additional parts to control in some designs of the prior art. Adjustment to any setting is always less than 1 turn.
BRIEF DESCRIPTION OF THE DRAWINGS
[0063] One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:
[0064] FIG. 1 is a rear elevational view of an apparatus according to the present invention shown mounted to the rear of a fire arm shown is shown schematically only in part cross-section.
[0065] FIG. 2 is a side elevational view of the apparatus of FIG. 1 .
[0066] FIG. 3 is a top plan view of the apparatus of FIG. 1 .
[0067] FIG. 4 is a rear elevational view along the lines 4 - 4 of the wheel and cam of the apparatus of FIG. 1 .
[0068] FIG. 5 is a rear elevational view along the lines 4 - 4 of the wheel and cam of the apparatus of FIG. 1 .
[0069] FIG. 6 is an exploded rear view taken in the same direction as FIG. 1 of the apparatus of FIG. 1 .
[0070] FIG. 7 is an exploded rear view taken in the same direction as FIG. 2 of the apparatus of FIG. 1 .
[0071] In the drawings like characters of reference indicate corresponding parts in the different figures.
DETAILED DESCRIPTION
[0072] An adjustable rear iron sight 10 is provided for a firearm 11 for cooperation with a fixed front sight (not shown) where the user aligns the front and rear sights to aim the fire arm in a required direction.
[0073] The sight comprises a rear sighting element 12 which is shown in the form of an aperture 13 carried in a screw-in insert portion 14 for mounting in a housing 15 . This is mounted generally at a rear of the fire arm and defines a visible alignment portion defined by the aperture for visual alignment by the user with the front sighting element (not shown). Other types of sighting elements can be used which allow the user to locate the rear sight relative to the front sight as are well known in the industry.
[0074] In general, the element 12 is carried on an a mounting member in the form of a mounting block 16 having mounting elements 17 for attachment of the mounting member 16 to the firearm 11 . An adjustable member 18 is carried on the mounting member 16 and is adjustably movable upwardly and downwardly relative thereto.
[0075] The sighting element 12 is mounted on the adjustable member 18 so that the upward and downward adjustment of the adjustable member 18 acts to change the height of the sighting element 12 on the firearm 11 so as to compensate for projectile drop over different distances.
[0076] A manually rotatable wheel 19 is mounted on the mounting member 16 for manual rotation by the user about an axis 20 of the wheel. The wheel 19 carries a snail cam 21 for rotation therewith having a generally spiral snail cam surface 22 defining a spirally changing radius from the axis 20 for engaging an abutment on the adjustable member 16 and moving the adjustable member 16 to a height determined by the radius at any selected position on the spiral cam surface 22 .
[0077] The wheel 19 has a plurality of distance markings 19 A on an outer circular visible surface 19 B thereof angularly spaced around the axis 20 for selection by the user of a required distance marking by rotating the wheel to a selected angular position determined by selection of the required distance marking. The markings are shown as 100 to 200 yards but can vary depending on the parameters of the fire are concerned.
[0078] The spiral cam surface has a profile of radius changes calibrated such that the distance markings 19 A are each associated with a respective required height of the adjustable member and therefore of the sight 12 carried by it.
[0079] The wheel 19 is cylindrical with an outer circular surface carrying the markings. A peripheral surface 19 C is knurled for finger adjustment. The wheel is readily removable and replaceable for replacement with a second wheel 19 D ( FIG. 4 ) having a cam 20 with a different profile 22 of the cam surface where the cam spiral cam surface of that wheel has a profile of radius changes calibrated relative to a different fire arm and/or to a different shot load.
[0080] The wheel 19 is attached to the mounting block 16 by a single screw 25 extending along the axis 20 and threaded into the block 16 at female thread 26 . The screw 25 defines a cylindrical surface forming a shaft 25 A for rotation of the wheel. The block 16 is mounted on the fire arm by pins 17 A passing through holes 17 forming the mounting elements. It will be appreciated that the block must be manufactured to accommodate the different mounting pin arrangements required for different fire arms. This mounts the block upstanding along the side of the fire arm with a side surface 16 A immediately adjacent the side of the fire arm and an opposed upstanding parallel surface 16 B adjacent the wheel 19 .
[0081] The rear sighting element 12 is mounted on the adjustable member 18 for side to side movement for adjustment of the rear sighting element to compensate for windage. This is effected by providing a thread 12 B on the sight 12 to cooperate with a screw 12 A mounted across an outwardly projecting portion 18 A of the adjustable member 18 . The screw 12 A is operable by a head not shown for fine screw adjustment across the portion 18 A of the sight 12 .
[0082] The adjustable member includes a main body portion 18 B mounted on top of the mounting block by a pair of upstanding pins 28 and 29 allowing vertical sliding movement of the adjustable member 18 along bores 31 and 32 in the mounting block 16 on the pins. The pins are attached by a threaded connection 33 A, 33 B at the upper end to the main portion 18 B of the adjustable member 18 . The pins 28 , 29 carry springs 34 , 35 for biasing the adjustable member onto the cam surface 22 of the cam 20 . The springs apply a downward force on shoulders 28 A and 29 A of the pins relative to shoulders 31 A and 32 A in the block 16 . Downward movement of the portion 18 B is limited by an adjustable screw stop 38 in a bore 39 which buts against the top surface of the block 16 . The pins 28 and 29 are held in place in the bores 31 , 32 by end caps which close the bores and allow the pins to slide though while locating the pin against side to side movement.
[0083] The wheel shaft 25 A is mounted between the pins 28 , 29 below the adjustable member 18 and the springs bias the adjustable member downwardly onto the cam surface so that the cam surface when rotated lifts the adjustable member 18 off the stop 38 .
[0084] The wheel and the mounting member include cooperating elements 40 for restraining the wheel in a plurality of angular positions corresponding to the distance markings on the wheel. The cooperating elements comprise a series of recesses 40 A in the surface 19 C of the wheel 19 and a ball 40 B biased by a spring 40 C for engaging into the recesses 40 A. The ball 40 B is held in place by a screw 40 D engaged into a bore 40 E in the block 16 .
[0085] Thus the upstanding block 16 includes the first upstanding side surface 16 A having the mounting pins 17 A for attachment of the mounting member to the firearm and the second parallel upstanding side surface 16 B immediately adjacent and carrying the wheel 19 .
[0086] Thus the apparatus includes the sight mounting block 16 which mounts the sight to said firearm 11 , said sight mounting block containing mounting holes 17 to allow attachment to said firearm. The spring and ball 40 apply force to maintain the position of the interchangeable multi-position cam 20 and cavities 40 A. The block 16 cooperates with the springs 34 , 35 and modified shoulder bolts 28 , 29 that control the vertical motion of the aperture mounting block 18 . The projectile drop compensation mechanism further comprises the mounting shoulder screw 38 and an interchangeable multi-position cam and wheel assembly 19 that raises the aperture mounting block 18 via the vertical elevation screw 38 against which it abuts. The cam profile is arranged to match the trajectory of the particular firearm and load. The aperture mounting block 18 contains threaded holes 39 for fastening the shoulder bolts 28 , 29 that control its vertical motion. The sight finally includes the horizontal windage screw 12 A, the threaded aperture block 12 and the aperture 13 .
[0087] To provide allowance to adjust windage, the horizontal windage screw is contained in the aperture mounting block 18 . Turning the screw clockwise causes the aperture block and aperture to move to the right as a result moving the point of impact to the right and turning the screw counter-clockwise causes the aperture block and aperture to move to the left as a result moving the point of impact to the left
[0088] To provide allowance to adjust elevation for the zero range, the vertical elevation screw 38 is contained in the aperture mounting block 18 . The point of the vertical elevation screw 38 rests on the profiled section 22 of the interchangeable multi position cam 20 . With the cam 20 set to its lowest setting, adjusting elevation for the zero range can be performed. Turning the screw 38 clockwise causes the aperture mounting block 18 to raise (containing the aperture block and aperture) as a result moving the point of impact higher. Turning the screw counter-clockwise causes the aperture mounting block 18 to lower (containing the aperture block and aperture) as a result moving the point of impact lower.
[0089] Projectile drop compensation is achieved by adjusting the interchangeable multi position cam 20 to the desired distance setting that is the closest match to the distance from the target. The profiled section 22 adds the necessary increase in elevation to the zero range due to its direct contact with the point of the vertical elevation screw 38 . The profile which has been machined into the cam 20 has been determined using ballistic data calculated from customer supplied load information and the spacing between the front and rear sight. If the customer wishes, additional interchangeable multi position cams can be purchased and the customer only needs to install the correct cam to be able to aim “dead on” at any distance selected between the minimum and maximum distance settings.
[0090] The front face 19 B of the wheel 19 of the interchangeable multi position cam displays distance settings in large easy to read numbers and lines. The distance intervals are close enough to allow the average point of impact to be will be within 1″ of the zero range at every setting. The circumference is knurled at 19 C to provide ease of adjustment. Cam position is maintained by pressure of the spring 40 C against the loaded ball 40 B located in the sight mounting block engaging the depressions 40 A in the rear surface 19 C of the wheel 19 of the cam.
[0091] Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.
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An adjustable iron sight for firearms includes compensation for projectile drop. The projectile drop compensation moves the sight aperture to compensate for projectile drop. Use of the compensation will allow aiming directly at the target without having to visually compensate for projectile drop. The projectile drop compensation mechanism includes a multi-position manually operable wheel and cam that is profiled to match the trajectory of the particular firearm and load. As there are many possible loads that could be used with a particular firearm, the multi-position cam is interchangeable to allow changing to a cam that is matched to the specific load that is desired.
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FIELD OF THE INVENTION
The invention concerns a storage box for doctor blades employed in servicing of the face of a roll in a paper/board machine.
BACKGROUND OF THE INVENTION
In prior-art solutions, the doctor blades have been stored in paper mills as straight blades in storage shelves for doctor blades. In such a case, there is a risk that a blade that is constantly exposed is damaged. Even a small dent in the blade face makes the blade unusable.
OBJECTS AND SUMMARY OF THE INVENTION
In the present patent application, an entirely novel solution for storage of blades is suggested. In the present patent application, it is suggested that a storage box be used for doctor blades. The doctor blades have been joined together from their ends, and the blades have been wound onto a reel. Said reel of doctor blades has been inserted into a storage box, and the doctor blades can be taken/pulled out of said storage box by unwinding the reel of doctor blades.
In accordance with the present invention, the storage box consists of two parts: a cover part and a bottom part. The cover part is fitted so that the edges of the cover are placed around the edges of the bottom part. The box is favourably of octagonal shape. According to the invention, separate bearing means which promote the rotation of the reel of doctor blades have been fitted inside the cover part and the bottom part of the box. Since the storage box is favourably made of cardboard, the bearing part has preferably also been made of cardboard. The bearing means preferably comprise two circular disks, against which the side faces of the reel R of doctor blades are placed. One of the circular disks has been fitted freely against one side face of the reel of doctor blades, and the other disk against the other side face. Further, one of the circular disks has been fitted to be placed against a backup bearing part, which is also made of cardboard. Favourably, both faces of both of the circular disks have been treated with a coating which reduces the friction. The coated bearing face of the circular disk is placed against a preferably likewise coated backup bearing face. One preferably silicon-coated backup bearing face for the circular disk 10 a 3 ′ is the plane face of a backup bearing part 10 a 3 ″, and a second preferably silicon-coated backup bearing face for the other circular disk 10 a 30 ′ is the inside plane face of the bottom part 10 a 1 .
The backup bearing part 10 a 3 ″ has been formed out of an octagonal plate so that the fold parts of the plate have been bent into an angle of 90° against the bottom face of the middle area of the plate. Said folded edges form a bearing face at the outer circumference of the reel R of doctor blades. Thus, the friction between the side face of the reel of doctor blades and the outer circumference is reduced. The other circular disk 10 a 30 ′ has been fitted between the other side face of the reel R of doctor blades and the inner face of the bottom 10 a 1 .
Thus, the storage box is provided with inside bearing means, which permit easy rotation of the reel of doctor blades and easy discharge of the reel, i.e. easy pulling of blades out of the interior of the box. The box operates all the time as a storage box until the last doctor blade has been pulled out of the interior of the box.
The storage box in accordance with the invention for doctor blades is characterized in what is stated in the patent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in the following with reference to some preferred embodiments of the invention illustrated in the figures in the accompanying drawings, the invention being, yet, not supposed to be confined to said embodiments alone.
FIG. 1A shows a storage box 10 in accordance with the invention for doctor blades as assembled. In its interior the storage box 10 includes a reel R composed of doctor blades t 1 , t 2 . . . , which can be discharged through an opening provided in the side face of the storage box.
FIG. 1B illustrates a reel R of doctor blades consisting of doctor blades t 1 , t 2 .
FIG. 1C is an exploded view of a storage box for doctor blades.
FIG. 2A shows the bottom/cover part of the storage box as spread out.
FIG. 2B illustrates folding of the edges of the bottom/cover part along the creases so that the edge parts are formed perpendicularly to the middle area while the edge parts are locked in slots placed at the edges of the middle area.
FIG. 2C shows the second stage of folding, i.e. interlocking of adjacent edge parts with each other.
FIG. 3A illustrates formation of the bearing part out of two jointly operative structural components. The illustration in the figure is an axonometric view in part.
FIG. 3B is a spread-out illustration of a backup bearing part.
FIG. 3C illustrates folding of the edges of the backup bearing part perpendicularly to the middle area in order to form the edge portion of the bearing arrangement.
FIG. 3D shows a bearing part, favourably a circular disk.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A is an axonometric view of a storage box 10 in accordance with the invention. The storage box 10 is favourably octagonal, and the material is corrugated board, cardboard, relatively stiff plastic, or equivalent. As is shown in the figure, the reel R of doctor blades can be discharged out of the storage box 10 through the discharge opening 11 .
FIG. 1B is an illustration of principle of formation of a reel R of doctor blades so that the doctor blades t 1 , t 2 . . . are joined together by means of a binding strap from their ends while the blade ends overlap each other.
FIG. 1C shows the storage box 10 as disassembled into its parts 10 a 1 , 10 a 2 and 10 a 3 . The storage box 10 comprises a bottom part 10 a 1 , a cover part 10 a 2 , and bearing means 10 a 3 placed in the interior of the box, which bearing means consist of a first bearing disk 10 a 3 ′, preferably a circular disk, and of a backup bearing part 10 a 3 ″, and of a second bearing disk 10 a 30 ′, preferably a circular disk. The disk faces of both circular disks 10 a 3 ′, 10 a 30 ′ have been coated with a material that reduces friction, favourably silicon. Similarly, the face planes of the backup bearing part 10 a 3 ″ and of the bottom part 10 a 1 , against which the circular disks 10 a 3 ′, 10 a 30 ′ will be placed, have been coated with a material that reduces friction, favourably silicon. As is shown in the figure, the storage box 10 is favourably octagonal, and so it can be placed readily on support of one of its side faces, in which case the doctor blades can be discharged from the reel R of doctor blades placed in the interior of the box through the through opening 11 provided in the side face of the storage box. The through openings 11 are placed in the same locations one above the other in the parts 10 a 2 , 10 a 1 and 10 a 3 ″, so that the doctor blades t 1 , t 2 . . . can be discharged from the reel R through the openings 11 provided in the parts 10 a 2 , 10 a 1 and 10 a 3 ″ of the storage box 10 .
FIG. 2A is a spread-out illustration of the bottom part 10 a 1 and the cover part 10 a 2 of the storage box. The bottom part 10 a 1 and the cover part 10 a 2 comprise eight edge parts, i.e. the edge parts P 1 , P 2 , P 3 , P 4 , P 5 , P 6 , P 7 , and P 8 . The edge parts are provided with creases D 1 , D 2 , D 3 . . . D 8 . The fold lines of the creases D 1 , D 2 , D 3 . . . D 8 ; D 2 ′, D 4 ′ . . . D 8 ′ form an octagon when the spread-out illustration of the part is viewed from above. At the edges of the bottom area e of the box, in connection with every second edge part P 2 , P 4 , P 6 . . . , there are corresponding slots f 1 , f 2 , and the fold edge P 2 ′ connected with the edge part P 2 related to said slots f 1 , f 2 . . . can be folded so that the locking tongues c 1 , c 2 . . . connected with said fold edge are inserted in the slots f 1 , f 2 .
When the box is assembled, the edge parts P 1 , P 2 . . . P 8 are raised so that they are perpendicular to the face plane of the bottom area e. Every second edge part P 1 , P 3 is folded so that, for example, the ends P 1a , P 3a . . . , which are inclined in relation to the directions or lines of the creases D 1 , D 3 , are placed between the edge parts P 2 , P 2 ′; P 4 , P 4 ′ . . . of the adjacent edge sectors. The edge tongues c 1 , c 2 of the fold edge P 2 ′ are locked in the corresponding slots f 1 , f 2 in the middle part e. The inclined end P 1A of the edge part P 1 is locked between the edge parts P 2 , P 2 ′.
FIG. 2B illustrates the formation of the bottom part 10 a 1 , and so also of the cover part 10 a 2 , of the storage box 10 for doctor blades so that the edge parts P 1 , P 2 , P 2 ′ are folded in the way described above so that the edge tongues c 1 , c 2 of the edge parts P 2 ′ are fitted into the corresponding slots f 1 , f 2 in the bottom area e. The construction of the cover part 10 a 2 is equal to the construction of the bottom part 10 a 1 . The cover part 10 a 2 has larger measures than the part 10 a 1 , and so the cover part 10 a 2 is fitted around the bottom part 10 a 1 .
FIG. 2C illustrates the part 10 a 1 , 10 a 2 as folded together, i.e. the ultimate stage of folding following after the stage shown in FIG. 2 B.
FIG. 3A illustrates formation of the bearing part 10 a ′ 3 . The bearing part 10 a 3 comprises a bearing part 10 a 3 ′, which is placed against the backup bearing part 10 a 3 ″. The part 10 a 3 ′ is a circular disk, whose outer face is provided with a coating, preferably a silicon coating, which reduces the friction. The outer face of the circular disk 10 a 3 ′ enters into contact with the backup bearing face N of the backup bearing part 10 a 3 ″. Said face N has also been treated favourably with a material that reduces friction, preferably provided with a coating, preferably a silicon coating.
FIG. 3B is a spread-out illustration of the part 10 a 3 ″. The part 10 a 3 ″ is likewise made of an octagonal construction, and it comprises eight edge parts M 1 , M 2 , M 3 . . . M 8 . The edge parts M 1 . . . M 8 are placed at the outer edge of the middle area e 2 of the plate part 10 a 3 ″, and they are provided with creases or crease lines n 1 , n 2 . . . n 8 . The edge part M 1 , M 2 . . . is provided with end edges i, which are placed perpendicularly to the creases n 1 , n 2 . . . , and with second end edges i′, which are placed as inclined in relation to said crease lines n 1 , n 2 . . . .
As is shown in FIG. 3C, the edge parts M 1 , M 2 . . . of the part 10 a 3 ″ are folded so that they are perpendicular to the plane of the middle area e 2 , in which case, for example, the inclined end edge i′ of the edge part M 1 is placed underneath the end edge i of the adjacent edge part M 8 .
FIG. 3D shows the bearing disk 10 a 3 ′ or 10 a 30 ′ as a separate illustration.
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The invention concerns a storage box A 0 ( 10 ) for doctor blades employed in servicing of the face of a roll in a paper/board machine. The box is a polygon construction, in whose interior the reel (R) formed by doctor blades (t 1 , t 2 ) has been fitted. Through an opening ( 11 ) in a side face of the storage box, the doctor blades (t 1 , t 2 , . . . ) can be discharged from the reel (R) placed inside the storage box ( 10 ). In its interior, the storage box ( 10 ) comprises bearing means, preferably at least one separate disk ( 10 a 3 ′), which has been fitted to revolve freely on the side face of the reel (R) formed by the doctor blades.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of U.S. patent application Ser. No. 08/992,235 which was filed on Dec. 17, 1997 now U.S. Pat. No. 6,009,941.
TECHNICAL FIELD
This invention relates to the handling of downhole well tools and tubing strings, and in particular to an apparatus for axially displacing a downhole well tool or tubing string in a well bore equipped with a wellhead, the downhole well tool being supported by a tubing string in the well which includes a telescoping joint to permit the axial displacement of the downhole well tool and the tubing string. As well as any downhole operation in which well tubulars or downhole equipment is manipulated or downhole operations are performed in which pressure containment is necessary.
BACKGROUND OF THE INVENTION
Downhole operations and the handling of downhole well tools in completed wells has always presented a certain challenge, especially when working in wells having a natural pressure that exceeds atmospheric pressure, necessitating the containment of the well at all times. A further challenge has been the maintenance of well bores which pass through production zones that are not well suited to continuous production. For example, a production zone which yields both water and oil or gas or any combination thereof may require relatively frequent repositioning of a lower end of a production tubing in order to recover oil or gas efficiently. Production zones which produce crude oil high in waxy compounds or asphaltines, or laden with salts, which tend to plug casing perforations and therefore require frequent treatment to maintain an economic flow of hydrocarbon are further examples of such production zones.
To date, the maintenance of such wells has proven time-consuming and expensive. For example, in wells which produce both oil, water and gas and/or water and gas and have a mobile water/hydrocarbon interface, the production of hydrocarbon gradually decreases over time until only water or gas is produced from the well. Relocation of the bottom end of the production tubing string is then required to recommence oil production. The relocation of the tubing string has been a complex process which involved many time-consuming and expensive steps that are well known in the art. It is not difficult to appreciate that there is a need for a more efficient and less costly system for producing oil or gas from such wells. Such a system is described in applicant's copending patent application incorporated herein by reference. The apparatus described in that patent application eliminates many of the shortcomings of prior art procedures for selectively producing fluids from wells, performing barefoot completions of well bores in sensitive zones, and other downhole operations using production tubing and tools that require axial displacement within a limited range in a well bore. At the time of filing that patent application, it was considered that the apparatus described in U.S. Pat. No. 4,867,243 which issued on Sep. 19, 1989 to Garner et al. would be suitable for effecting the axial displacement of the downhole well tools. It has now been recognized that such prior art tools for inserting mandrels through wellheads is not necessarily adequate or optimal for performing the axial displacement of such downhole well tools.
There are several reasons why such prior art tools are not optimal tools for this purpose. First, they are designed for inserting wellhead isolation mandrels into wellheads and withdrawing them from the wellheads after the well is serviced. Since wellhead isolation mandrels are of inconsequential weight, they are stroked through a wellhead relatively easily. Moving a tubing string of 4,500′ (1,500 meters), which is not uncommonly encountered in handling downhole well tools, may require a force in excess of 50 tons. The force required is due not only to the considerable weight to be lifted but also to the extra force required to unseat anchors and/or packers supporting the tubing string. Such forces may subject the wellhead to potentially damaging stresses. Second, wellhead isolation tools provide no mechanism for rotating a downhole tubing string since rotation is not required for the insertion or withdrawal of a wellhead isolation mandrel. When manipulating a downhole tubing string, however, rotational movement is often required in order to release or set components such as packers, anchors, hangers and the like. Considerable rotational force may be required to accomplish the release of such components and it is therefore desirable to provide a mechanism for selectively rotating the downhole string as required.
It has also now been recognized that certain downhole operations can be more economically performed through the wellhead with pressure containment than performing those operations using a rig, for example. It is also known that certain near-surface operations such as the drilling out of permanent bridge plugs, cement plugs or any other obstruction in the casing column during re-entries require pressure containment in order to avoid the escape of hydrocarbons to atmosphere and potentially dangerous releases of contained pressure. There therefore exists a need for an apparatus which is adapted to provide pressure containment while enabling downhole manipulations to move production tubing, and remove near-surface obstructions with or without the use of a telescoping joint in a tubing string.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an apparatus for axially displacing a downhole tool or tubing string in a well bore equipped with a wellhead which is robust enough to permit a lengthy tubing string to be displaced in the well bore.
It is a further object of the invention to provide an apparatus for axially displacing a downhole tool or tubing string in a well bore equipped with a wellhead which permits a tubing string alone or a tubing string supporting the downhole tool to be rotated, if required.
It is yet a further object of the invention to provide an apparatus for axially displacing a downhole tool or tubing string in a well bore equipped with a wellhead which is stabilized to reduce stress on the wellhead.
It is yet a further object of the invention to provide an apparatus for axially displacing a downhole tool or tubing string in a well bore equipped with a wellhead which is safe to use.
It is also an object of the invention to provide an apparatus for axially displacing a downhole tool or tubing string in a well bore equipped with a wellhead which is readily transported from one well bore to another.
It is a further object of the invention to provide an apparatus for performing downhole operations which require pressure containment at the wellhead.
These and other objects of the invention are realized in an apparatus for axially displacing a downhole tool or tubing string in a well bore equipped with a wellhead, the downhole tool being supported by a tubing string in the well which includes a telescoping joint to permit the axial displacement of the tool, comprising:
a lift rod string;
a tool entry spool adapted to be mounted to a top of the wellhead;
at least one annular seal for containing well pressure mounted above the tool entry spool, the annular seal providing a fluid seal around a periphery of the lift rod string;
means for axially displacing the lift rod string;
means for selectively rotating the lift rod string; and
a swivel joint for enabling free rotational movement in a link rod between the means for axially displacing the lift rod string and the means for selectively rotating the lift rod string.
The apparatus in accordance with the invention includes a lift rod string which is equipped with a releasable latch tool for connecting a free end of the lift rod string to a latch point in or near a telescoping joint described in applicant's copending patent application, or connected directly to a tubing string. The lift rod string is supported on its top end by a stem which is connected to the means for selectively rotating the lift rod string. The means for selectively rotating the lift rod string is preferably a motor. A hydraulic or an electric motor or a mechanical rotational device can be used. Attached to the stem for supporting the lift rod string is a link rod that includes a swivel joint for enabling free rotational movement between the stem for supporting the lift rod string and the means for axially displacing the lift rod string. The means for axially displacing the lift rod string is preferably a hydraulic cylinder or a mechanical jack, but any other hoisting mechanism may be used.
In preferred embodiments of the apparatus designed for use on deep wells, the apparatus is supported and stabilized by adjustably extendible support posts designed to rest on a ground surface surrounding the wellhead. The support posts help bear the weight of heavy tubing strings and stabilize the apparatus to reduce torsional stress on the wellhead.
The apparatus preferably includes a tool entry spool adapted to be mounted to a top of the wellhead. The tool entry spool provides a space for accommodating a latch tool such as a spear, key, collet, slip or friction type tool, attached to the bottom end of the lift rod string. Mounted above the tool entry spool is at least one annular seal for containment of well pressure. The annular seal may be a stuffing box, but it is preferably one or more blowout preventers. Desirably, a spool which includes at least one tool window is provided above the blowout preventer. The tool window provides access to the lift rod string with gripping or locking devices useful for inhibiting axial or rotational movement while lift rod joints are being inserted or removed. Alternatively, a pair of oppositely oriented well slip assemblies such as described in U.S. Pat. No. 3,846,877 which issued on Nov. 12, 1974 to Spiri, the entire specification of which is incorporated herein by reference, can be used in place of the tool access spool to selectively inhibit axial or rotational movement of the lift rod string.
Each joint of the lift rod string may include axial bores which permit fluid to be circulated or pumped straight through the lift rod string, if required. For example, conditions are sometimes encountered in wells such as gas wells where hydrating frequently occurs at or near the well surface. Such hydrates can prevent entry or retrieval, or foul or seize latch tools such as spears, keys, collets, slips type or friction type tools and prevent their release or proper functioning. If the lift rod string includes axial bores to permit the circulation of hot fluid, the string can be heated to melt ice or paraffins, etc. and free up the seized component to effect the desired release. One way of circulating fluid through the lift rod string is to use aligned bores that extend through the means for axially displacing the lift rod string so that a fluid connection can be made at the top of the apparatus. If a hydraulic cylinder is used for axially displacing the lift rod string, the hydraulic cylinder is provided with a polished rod that extends through a top of the cylinder. A free end of the polished rod is equipped with threaded connectors for the attachment of fluid circulation hoses which are in turn connected to a pump and a heated reservoir. It may also be desirable to pump fluid straight through a lift rod string. This can be advantageous for clearing hydrates or paraffin buildup from a production tubing. One way of accomplishing this is by modifying the spear, collet, slip or friction type tool to let fluid flow out a bottom end of the lift rod string, or to run in the lift rod string without a tool on its bottom end so that fluid can be pumped through one or both axial bores.
The apparatus in accordance with the invention may also be used to axially or rotationally displace tubulars in a well bore that are not equipped with telescoping joints. If slip or spear latch tools, for example, are used, a production tubing, or the like, can be repositioned in a well without killing the well or removing the wellhead. Depending on the downhole components associated with the tubing string, it is possible and practical to remove an entire production tubing string from a well without removing the wellhead.
The apparatus in accordance with the invention also enables downhole operations, in particular near-surface operations which require pressure containment. Such operations include the drilling out of permanent bridge plugs, cement plugs or any other obstruction in the casing column near the surface during re-entries to a well bore.
Although the apparatus in accordance with the invention is versatile and robust, it may be easily disassembled for transport to another well site. It can also be transported without disassembly, permitting well bores to be readily serviced at minimal cost.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be explained by way of example only, and with reference to the following drawings wherein:
FIG. 1 is a cross-sectional view of a first preferred embodiment of the apparatus in accordance with the invention connected to a wellhead of a well bore;
FIG. 2 is an elevational view of the apparatus shown in FIG. 1;
FIG. 3 is an elevational view of a second preferred embodiment of an apparatus in accordance with the invention;
FIG. 3 a is an enlarged cross-sectional view of a connection between a stem and a lift rod joint in accordance with the invention, showing the arrangement of fluid circulation bores in each;
FIG. 4 is an elevational view of another preferred embodiment of the apparatus in accordance with the invention;
FIG. 5 is an elevational view of yet a further preferred embodiment of the invention suitable for use in shallow wells where production tubing string weights are moderate; and
FIG. 6 is a cross-sectional view of the apparatus shown in FIG. 1 connected to a telescoping joint described in applicant's copending patent application.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
This invention relates to an apparatus for axially displacing a downhole tool or a tubing string in a well bore equipped with a wellhead, the downhole tool being supported by the tubing string in a well to permit axial displacement of the downhole tool or tubing string. The apparatus in accordance with the invention may also be used for performing downhole operations that require pressure containment to ensure that hydrocarbons are not released to atmosphere and concessive pressure releases do not occur during such operations.
FIG. 1 shows a cross-sectional view of a first preferred embodiment of an apparatus in accordance with the invention, generally indicated by the reference 10 . The apparatus is mounted to a top of a wellhead generally indicated by reference 12 . Typically, the wellhead 12 includes a surface spool 14 and a master valve spool 16 , the structure of each being well known in the art. Some wellheads do not include master valves. Mounted to a top of the master valve spool 16 or an uppermost part of the wellhead is a tool entry spool 18 , which is the lowermost component of the apparatus 10 . The tool entry spool 18 accommodates a latch tool 96 (see FIG. 6) for connecting a lift rod string 20 to a latch point 94 of a telescoping joint 90 or directly to a downhole tubular when the lift rod string 20 is run into the well bore, as well as when it is removed from the well bore, as will be explained in detail with reference to FIG. 6 . Mounted to a top flange 19 of the tool entry spool 18 is an annular seal for containing well pressure, such as a blowout preventer 22 . As will be understood by those skilled in the art, other annular seals for containing well pressure can be adapted for use with the apparatus 10 . For example, certain stuffing box structures or multiple ram type or annular preventers can be adapted for such use. The blowout preventer 22 is preferred, however, because of the ease of use and the security of the seal it provides. Preferably, the apparatus includes two blowout preventers 22 connected in sequence in order to increase the safety of the apparatus and to provide extra room between the master valve spool 16 and the uppermost blowout preventer 22 to accommodate latch tools 96 of different lengths. With two or more blowout preventers safety is increased because the preventers can be opened and closed in sequence at each lift rod joint connector in the lift rod string to prevent tears in sealing surfaces which can result from forcing rough surfaces at the connectors through a closed preventer. For this reason, it is preferable that the adjacent preventers be spaced about 10-13 cm (4″-5″) apart to accommodate a lift rod joint connector between them.
Mounted to a top of the uppermost blowout preventer 22 is a tool access spool 24 having at least one tool window 26 or an integral locking mechanism (not illustrated). The tool window 26 permits gripping or locking devices to be inserted for engaging the lift rod string. As will be explained below in some detail, the tool window 26 permits the lift rod string 20 to be gripped to permit joints to be added to, or removed from, the lift rod string 20 . It also permits the lift rod string 20 to be locked against axial movement when joints are being added to, or removed from, the lift rod string 20 . For example, the weight of the tubing string 94 can be supported at the tool window 26 in low pressure wells while lift rod string joints are being added, or removed. If wells with exceptionally high pressure are being worked, a lock inserted through the tool window 26 prevents the lift rod string 20 from being forced up out of the well bore while joints are being added to, or removed from, the lift rod string.
The tool access spool can be replaced by a pair of oppositely oriented well slip assemblies described in U.S. Pat. No. 3,846,877 to Spiri. Preferably, two oppositely oriented slip tools are mounted to a top of the uppermost blowout preventer 22 . They may be operated separately, or in unison, to control axial or rotational movement of the lift rod string 20 , as required by well and/or operating conditions.
Bolted to the top flange 25 of the tool access spool 24 is a lower support plate 28 which is preferably supported by a plurality of support posts 30 a to reduce compressive and torsional forces on the wellhead which may be induced by the lifting and manipulation of heavy production tubing strings. The number of support posts 30 a is a matter of design choice. Preferably at least three are provided and four support posts 30 a are considered more appropriate for supporting the lower support plate 28 . Located above the lower support plate 28 is an upper support plate 32 which is supported by support posts 30 b . The support posts 30 b may be integral extensions of support posts 30 a or may be separate posts which threadably engage threaded bores in the lower support plate 28 . For the sake of rigidity and optimal support, it is preferable that the support posts 30 a and 30 b be integral and that the support posts 30 a,b pass through bores in the lower support plate 28 . The support posts 30 a,b may be secured to the lower support plate 28 in any one of several ways well known in the art, such as pins, wedges, set screws or the like.
Reciprocally moveable between the lower support plate 28 and the upper support plate 32 is a travelling support plate 34 . The travelling support plate 34 includes bores 37 which receive the upper support posts 30 b with adequate clearance to permit the travelling support plate 34 to move reciprocally between the upper support plate 32 and the lower support plate 28 without undue resistance. The support posts 30 b stabilize the travelling support plate 34 and inhibit it from rotational movement when a motor 36 is operated to rotate the lift rod string 20 . Affixed to the travelling support plate 34 is the motor 36 for selectively rotating the lift rod string 20 . The stator 38 of the motor 36 is mounted to the travelling support plate 34 and the rotor 40 is attached to a link rod 42 . The link rod 42 connects the lift rod string 20 with a piston rod 44 of a hydraulic cylinder 46 , which provides the motive of force for axially displacing the lift rod string 20 and the tubing string 94 to which it is attached, as will be explained below in more detail with reference to FIG. 6 . The motor 36 may be a hydraulic motor or an electric motor, for example. A hydraulic motor such as the Bowen PS-60 Power Sub available from Bowen Tools, Inc., a division of IRI International Corporation, is suitable for most applications. An electric motor with equivalent torque can also be used.
Interconnecting the link rod 42 and the piston rod 44 is a swivel joint 48 which permits free rotation of the link rod 42 with respect to the piston rod 44 to permit the lift rod string 20 to be selectively rotated without causing damage or wear in the hydraulic cylinder 46 . The hydraulic cylinder 46 is mounted to a top surface 56 of the upper support plate 32 by one or more mounting brackets 50 in a manner well understood in the art.
FIG. 2 shows an elevational view of the apparatus 10 shown in FIG. 1 . As described above, four supports posts 30 a,b preferably support the lower support plate 28 , the upper support plate 32 and stabilize the travelling support plate 34 . In plan view, the respective support plates 28 , 32 and 34 may be square, circular, hexagonal or any other convenient shape. The travelling support plate 34 is shown in a position in which the piston rod 44 is nearing an end of its stroke. As described above, the travelling support plate 34 freely reciprocates between the lower support plate 28 and the upper support plate 32 with the extension and retraction of the piston rod 44 . The only other component of the apparatus shown in FIG. 2 which was not described above is a valve 52 preferably provided on the tool entry spool 18 . The valve 52 permits the release of well pressure after the lift rod string 20 has been withdrawn from a well and the master valve 16 has been closed but before the BOPs 22 are opened. Each BOP 22 also includes one or more of bleed off or equalization valves 54 , which are well known in the art. The operation of the apparatus shown in FIG. 2 will be described below with reference to FIG. 6 .
FIG. 3 shows an elevational view of another preferred embodiment of the apparatus in accordance with the invention. The apparatus shown in FIG. 3 is similar to that shown in FIGS. 1 and 2 with the exception that the travelling support plate 34 is eliminated and the stator 38 of the motor 36 is mounted to a top surface 56 of the upper support plate 32 . As shown in dotted lines, the upper support plate includes a guide roller assembly 58 through which a splined link rod 60 extends. The splined link rod meshes with a splined hub (not illustrated) of the rotor 40 (see FIG. 1) of the motor 36 . The splined link rod 60 reciprocates through the splined hub to permit the lift rod string 20 to be axially displaced. A swivel joint 48 connects the piston rod 44 to the splined link rod 60 as described above with reference to FIG. 1 . The mounting brackets 50 which support the hydraulic cylinder 46 are elongated to support the hydraulic cylinder about the length of its stroke above the upper support plate 32 .
The embodiment shown in FIG. 3 also illustrates a further feature of the invention which may be implemented in the embodiments shown in FIGS. 1, 4 or 5 as well. In the embodiment shown in FIG. 3, a polished rod 62 extends through a top end of the hydraulic cylinder 46 . The polished rod 62 is attached to the piston of the hydraulic cylinder 46 and reciprocates with the piston through seals in a top wall of the hydraulic cylinder 46 in a manner well known in the art. A top end of the polished rod 62 includes connectors 64 to which fluid circulation hoses may be attached. The fluid circulation hoses permit fluids to be circulated through axial bores in the polish rod 62 , the piston of the hydraulic cylinder 46 , the cylinder rod 44 , the swivel joint 48 , the splined link rod 60 and each joint of the lift rod string 20 . The fluid circulation bores are useful in certain instances where it is advantageous to circulate fluid through the lift rod string 20 . For example, in certain gas wells it is not unusual to have hydrate conditions near the top of the well bore in which ice accumulates on tools and connections. In oil wells, paraffins accumulate on tools and connectors. Under either of these conditions, it is possible for a latch tool 96 (FIG. 6) such as a spear, key, collet, friction or slip type connector to freeze or become clogged with hydrates or paraffins. If that happens, it may not be possible to release the latch tool 96 or move the lift rod string 20 unless the latch tool 96 can be heated to melt accumulated hydrate or paraffin deposits. It is therefore advantageous to circulate heated fluid such as heated oil through the lift rod string 20 when this occurs.
FIG. 3 a shows an enlarged cross-sectional view of the connection between the lift rod string 20 and the splined link rod 60 . Joints in lift rod string 20 have similar connectors. A fluid circulation bore 66 is an axial bore which extends through each lift rod string joint 20 and the splined link rod 60 so that the ends of the bores are connected when the two are securely screwed together. A recirculation bore 68 is radially offset from the fluid circulation bore 66 . Since the recirculation bore 68 in one component may not align with the recirculation bore 68 in the other component when two joints are connected, a recirculation chamber 70 is machined in the bottom of each female component of the joint so that a fluid recirculation path is enabled even though the two recirculation bores 68 are not aligned when the components are securely connected. The swivel joint 48 is constructed in the same manner to permit the swivel joint to freely turn while ensuring that fluid circulation is not inhibited.
FIG. 3 a also shows a further feature of the invention in which each joint of the lift rod string 20 includes opposed peripheral areas of reduced diameter to provide parallel tool gripping surfaces 72 that are adapted to be engaged by a clamping or securing device to permit joints to be added to, or removed from, the lift rod string 20 and to permit the lift rod string 20 to be secured to prevent axial movement when joints are added or removed. Clamping or securing devices used for this purpose are well known in the art and may include wrenches or hydraulic or mechanical clamps, all of which are commercially available.
FIG. 4 shows yet another embodiment of the apparatus 10 in accordance with the invention. The embodiment shown in FIG. 4 is identical to the embodiment shown in FIG. 1 with the exception that the hydraulic cylinder 46 is replaced with a mechanical jack 74 that has an axially displaceable jackpost 76 , such as a ball jack which is well known in the art. A lower end of the jackpost 76 is affixed to the swivel joint 48 which is in turn affixed to the link rod 42 . Reciprocal movement of the jackpost 76 is effected by rotation of a drive shaft 78 . The drive shaft 78 may be rotated by a hydraulic motor, an electric motor or the like, as appropriate. A mechanical jack such as the ball jack 74 is capable of securely moving significant loads and provides a safe mechanism for shifting the position of very long tubing strings in deep wells.
FIG. 5 shows another preferred embodiment of the invention principally intended for use on shallow wells where production tubing strings are of a weight that is safely supported directly by the wellhead. In this embodiment, support posts 80 are bolted directly to a top flange 25 of the tool access spool 24 . The number of support posts 80 is a matter of design choice but at least three are required and preferably at least four are used. The top end of the support posts 80 are bolted directly to a bottom flange 82 of a hydraulic cylinder 46 and supports the hydraulic cylinder 46 above the tool access spool 24 . A smaller version of the travelling support plate indicated by reference 84 reciprocates with movement of the piston rod 44 as explained above with reference to FIG. 1 . The stator 38 of the motor 36 is mounted to the travelling support plate 84 , as also explained with reference to FIG. 1 . In operation, the apparatus shown in FIG. 5 functions the same as the apparatus described above with reference to FIGS. 1-4. The apparatus is somewhat lighter and easier to handle, which makes it ideal for use in areas where there are an abundance of shallow wells that require service.
FIG. 6 is a cross-sectional view of the apparatus 10 described above with reference to FIGS. 1 and 2 mounted to a wellhead in which a production tubing 94 produces oil from a formation B that bears gas, oil and water. As is understood by those skilled in the art, such wells may require frequent service in order to maintain oil production as the gas/oil/water interface moves upwardly or downwardly with the production of hydrocarbons from the well. In certain areas, the gas/oil/water interface may move upwards several feet annually. In order to produce principally a selected fluid from such formations, the applicant has invented an apparatus generally indicated by reference 86 for isolating fluid zones in a casing 88 of a well bore. Periodically, the apparatus 86 must be repositioned within the casing 88 . This is accomplished using one of the preferred embodiments of the apparatus 10 in accordance with the invention. In an initial step in the process, the apparatus 10 is attached to the top of the wellhead 12 as described above with reference to FIGS. 1-5. If the well is a deep well, the apparatus is preferably one of those described with reference to FIGS. 1-4. If the well is a shallow well, any one of the apparatus shown in FIGS. 1-5 may be used.
After the apparatus 10 is bolted to a top of the wellhead 12 , the adjustable support pads 31 located respectively at the base of each support leg 30 a are adjusted so that the apparatus 10 is level and the support legs 30 a will share the load to be placed on the apparatus 10 when the lift rod string 20 supports the tubing string 94 . Once the apparatus 10 is properly set up, the lift rod string 20 is assembled using a plurality of joints which are interconnected. Attached to a free end of the first joint is a latch tool 96 for releasably connecting to a latch point 92 of a telescoping joint 90 described in applicant's copending patent application. The telescoping joint 90 permits the tubing string 94 and the apparatus for isolating fluid zones 86 to be axially displaced in the casing 88 . The latch point 92 is engaged by any one of a number of well known latch tools 96 which may include quick-disconnect threads, spears, keys, collets, friction or slip type tools, releasable packers or rotary taper taps, each of which is commercially available from several manufacturers and well known in the art. The latch tool 96 is shown in an engaged position with the latch point 92 at the bottom of the telescoping joint 90 . After the lift rod string 20 has been extended down through the telescoping joint 90 and a connection with the latch point 92 has been effected, the downhole tool 86 may be raised or lowered within the range of the telescoping joint 90 . This permits a variety of downhole tool manipulations to accomplish tasks such as those described in applicant's copending patent application without setting up a derrick or bringing in a crane, killing the well or performing many of the other steps required using prior art methods.
To run the lift rod string 20 into the well, a latch tool 96 is attached to a first joint of the lift rod string 20 and the joint is connected to the stem 41 at the end of the link rod 42 . The hydraulic cylinder is extended until the tool grip surfaces 72 are in the tool window 26 of the tool access spool 24 . The tool grip surfaces 72 are then engaged using a locking tool inserted through the tool window 26 , the motor 36 is operated to release the stem 41 from the first joint of the lift rod string 20 , the piston of the hydraulic cylinder is stroked back to the top of the cylinder 46 and another lift rod joint is added between the first joint and the stem 41 . The hydraulic motor 36 is operated to make the connection between the first and second joints of the lift rod string 20 and the stem 41 . The locking tool is then released from its grip on the tool grip surfaces 72 of the lift rod string 20 , the hydraulic cylinder 46 is stroked downwards until the tool grip surfaces 72 of the second joint appear in the tool window 26 , and the process is repeated until the latch tool 96 engages the latch point 92 of the telescoping joint 90 . After engagement of the latch tool 96 with the latch point 92 , the lift rod string 20 is tensioned to remove weight from compression anchors, hangers or packers 98 which support the tubing string 94 in the casing 88 , and the motor 36 is operated to rotate the tubing string 94 by rotation of the lift rod string 20 to release the anchors, hangers or packers 98 . A production packer 100 is released in the same way. Once the anchors, hangers or packers 98 and the production packer 100 are released, the tubing string may be raised or lowered in the casing 88 by adding or removing joints of the lift rod string 20 as described above. When the downhole tool 86 has been repositioned to a new location in the well bore, the motor 36 is operated to reset the anchors, hangers or packers 98 and the production packer 100 .
After the anchors, hangers or packers 98 and the production packer 100 are reset, the latch tool 96 may be released from the latch point 92 using methods well known in the art. For example, if the latch tool 96 is a releasing spear, release is accomplished using a “bump down” to break the attachment. The releasing spear is then rotated two or three times to the right. The rotation moves a releasing spear mandrel up through a grapple of the releasing spear, forcing the grapple against a release ring and putting the spear in the released position. A straight upward pull will then generally free the spear, however, it is recommended that the spear be rotated slowly to the right when coming out. The motor 36 is operated to accomplish the rotation. The lift rod string 20 is then disassembled in reverse order of the process described above for adding joints to the lift rod string 20 . After the latch tool 96 is withdrawn above the wellhead 12 , the master valve in master valve spool 16 (see FIGS. 1-4) is closed and well pressure is bled off through the release valve 52 in the tool entry spool 18 . The BOPs 22 are fully opened after the well pressure is bled off through the release valve 52 , the latch tool 96 is stroked up through the BOPs and the last joint of the lift rod string 20 is removed. The apparatus 10 may then be disconnected from the top of the wellhead 12 and the well may be put back into production.
As will be understood by persons skilled in the art, the apparatus in accordance with the invention may be used to displace tubulars in a well bore that are not equipped with a telescoping joint. Spears, friction or slip type tools may be used as latch tools to grip downhole tubulars for displacing the tubulars to add or remove joints, as required. Because of the structure of the apparatus in accordance with the invention, this can be accomplished while well pressure is contained, as is well understood in the art.
The apparatus in accordance with the invention can also be used for downhole operations which require pressure containment. Such operations include the drilling out of permanent bridge plugs, cement plugs or any other obstruction in the casing. Normally, such operations are required when abandoned well bores must be re-entered. Consequently, the permanent bridge plugs, cement plugs or other obstruction in the casing are generally near the surface. In order to re-enter an abandoned well, the apparatus 10 in accordance with the invention is connected to a wellhead of the abandoned well bore. If the well bore is not equipped with a wellhead, a wellhead is installed before re-entry operations are begun.
After the apparatus is set up, a hydraulically driven bit is connected to the bottom of the tubular which is ran down through the apparatus and fluids are pumped through the tubular to operate the bit while the BOPs 22 contain any potential pressure release from the re-entered well bore. Consequently, the removal of permanent bridge plugs, cement plugs, or any other obstruction in the casing can be safely and economically performed without danger of release of concessive pressures or hydrocarbons from the re-entered well bore.
Although only a few processes for the relocation of a downhole tool has been described, it will be understood by those skilled in the art that the apparatus in accordance with the invention can be used for any of the processes described in applicant's copending application as well as processes that have yet to be discovered. For example, it can also be used to accomplish such tasks as setting plugs, packers or subsurface safety control valves in a production tubing string using the lift rod string 20 for running those components into the tubing string. As will be understood by those skilled in the art, there is no practical limit to the length of a lift rod string 20 , so even deep well operations can be accomplished, if required. The light weight and versatility of the apparatus make it ideal for many operations now accomplished using much heavier rigs which are more expensive to construct and maintain.
Changes and modifications to the embodiments described above will no doubt become apparent to those skilled in the art. The scope of this invention is therefore intended to be limited solely by the scope of the appended claims.
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An apparatus for axially displacing a downhole tool or a tubular in a well bore equipped with a wellhead is described. The apparatus includes a lifting mechanism such as an hydraulic cylinder or a mechanical jack that is connected to a lift rod string. The lift rod string includes a latch for engaging the tubular or the downhole tool. The apparatus further preferably includes a motor for rotating the lift rod string to permit rotationally releasable downhole equipment to be released by rotational movement of the lift rod string. The apparatus is also useful for removing obstructions in a casing of the well bore, and for removing soluble solids from a tubular in the well bore. The advantage is a simple, light weight, lifting apparatus that is versatile, yet inexpensively manufactured and readily transported from one wellhead to another.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method of operating service provider management systems using a content-control and nudging based process to ensure quality and facilitate knowledge build-up. Further, the invention relates to a computer-based service provider management system configured to support such a method.
BACKGROUND OF THE INVENTION
[0002] Before the method and computer based system of the present invention there was no method or computer-based system using a content-controlled and nudging based process to ensure quality and knowledge build-up that is independent of subsequent quality control and knowledge collection within service provider management organizations. Conventionally such systems has been developed based on best practice frame processes to create an environment of processes and systems for carrying out case management in the best possible way. However, such systems lack the ability to effectively control the system of the case management based on effective processes based on competences and experience due to the complexity of such systems. Thus a need exists to provide a case management system with improved process control to ensure high quality management of service requests in service provider management organizations.
DISCLOSURE OF THE INVENTION
[0003] On this background, it is an object of the present application to provide a method of operating a service provider management system wherein the workflow when handling a service request is controlled through a set of operational standard processes prompted systematically in a specific order to ensure that users of the service provider management system provides the information intended in the design of the system to achieve the highest possible quality of the service requests handled by the service provider management system.
[0004] This object is achieved by providing a method of operating a service provider management system having an operator interface and an input component, said method comprising the steps of:
receiving a service request in the system from a requestor being serviced by a service provider; allocating a portion of the operator interface to a set of predefined logging input fields comprising a set of mandatory logging input fields; prompting an operator to input or select facts relating to the service request in the logging input fields; verifying that mandatory logging input fields has been completed before allowing the next step to be initiated; thereafter allocating said portion of the operator interface to a set of predefined initial diagnosis input fields, said set of predefined initial diagnosis input fields comprising mandatory initial diagnosis input fields; prompting an operator to input or select an initial diagnosis in the set of initial diagnosis input fields; verifying that the mandatory initial diagnosis input fields have been completed; thereafter allocating said portion of the operator interface to a set of predefined diagnosis output fields, said set of predefined diagnosis output fields comprising mandatory diagnosis output fields; prompting an operator to input or select a diagnosis output in the set of diagnosis output fields; verifying that the mandatory diagnosis output fields have been completed; issuing a service request reply comprising the diagnosis output; thereafter allocating the portion of the operator interface to a set of closure fields comprising mandatory closure fields; prompting an operator to input or select facts relating to closure in the set of closure fields; verifying that the mandatory closure fields have been completed; closing the service request; and outputting the facts from the mandatory closure fields to a database.
[0021] In an embodiment of the method according to the invention, the step of allocating a portion of the operator interface to a set of predefined logging input fields comprising a set of mandatory logging input fields further comprises the steps of:
prompting an operator to input or select a service request category; verifying that the service request category has been input or selected, and defining a sequence of the set of predefined logging input fields based on the service request category.
[0025] By initially selecting a service request category the workflow may be tailored to the exact service request type, such that the user only has to acknowledge the relevant input fields or have access to additional tools such as category specific dropdown lists or search tools.
[0026] In an embodiment the method according to the invention, the service request category is an incident management, a transition management, knowledge management, change management or a request management.
[0027] In an embodiment the method according to the invention, the service request category is a change management, a request fulfillment management or an access management.
[0028] In an embodiment of the method according to the invention, one or more of the steps of prompting an operator to input or select facts, an initial diagnosis, a diagnosis output or facts relating to closure further comprises the step of:
nudging the operator to input or select one or more mandatory or optional fields.
[0030] The mandatory input fields required by the system to be input may be further supported to achieve the highest possible quality of the service request management and therefore the method may also comprise a step of nudging the user to input optional fields to increase the quality. Even the step of inputting mandatory input fields may comprise a step of nudging the user e.g. to a specific type of input again to increase the quality of the handling of the service request or to improve the efficiency by which service requests are handled by the method according to the invention.
[0031] In an embodiment of the method according to the invention, the step of nudging the operator to input or select one or more optional fields comprises prompting the operator with information from earlier similar service requests to lessen the burden of inputting or selecting one or more optional fields thereby improving quality of the operator input.
[0032] An effective nudging step is the prompting of one or more earlier inputs in a specific input field to allow the user to get an idea of the type of input relevant in the input field e.g. length and content of the input.
[0033] In an embodiment of the method according to the invention, the step of nudging the operator to input or select one or more mandatory or optional fields comprises prompting the operator with a direct link to a knowledge database to allow the operator quickly to seek information to lessen the burden of inputting or selecting one or more optional fields thereby improving quality of the operator input.
[0034] Quick access to a knowledge database may nudge the user to seek information from earlier or similar service requests, which in effect again increases the quality in the handling of the service request.
[0035] In an embodiment of the method according to the invention, the step of nudging the operator to input or select one or more mandatory or optional fields comprises prompting the operator with information from earlier service requests to lessen the burden of inputting or selecting one or more optional fields thereby improving quality of the operator input.
[0036] In an embodiment of the method according to the invention, the step of allocating a portion of the operator interface to a set of predefined logging input fields comprising a set of mandatory logging input fields further comprises the step of:
displaying in the central portion facts from one or more similar service requests in the same service request category.
[0038] In an embodiment of the method according to the invention, the method further comprises the steps of:
prioritizing the service request by a service request priority; forwarding the service request to a buffer list of service requests; displaying a service request having the highest priority in the central portion.
[0042] In an embodiment of the method according to the invention, the step of allocating said portion of the operator interface to a set of predefined initial diagnosis input fields comprises the steps of:
allocating a field for a symptom associated with a problem of the service request; allocating a field for a triggering factor of the symptom associated with the problem.
[0045] In an embodiment of the method according to the invention, the method further comprises the step of prompting the operator to input or select which inputting fields associated with logging, initial diagnosis, diagnosis output or closure are relevant to future service requests such that the input or selected information from the operator may be made available in a knowledge database.
[0046] In an embodiment of the method according to the invention, the operator is prompted to tick off fields of relevance in a tick box associated with each fields, thereby indicating fields which are relevant to future service requests such that the ticked input from the operator may be made available a knowledge database.
[0047] In an embodiment of the method according to the invention, the step of allocating said portion of the operator interface to a set of predefined diagnosis output fields further comprises the step of:
allocating a direct link to a knowledge database in the portion of the operator interface.
[0049] In an embodiment of the method according to the invention, the step of allocating the portion of the operator interface to a set of closure fields comprising mandatory closure fields further comprises the step:
allocating a field for a case summary.
[0051] In an embodiment of the method according to the invention, the steps of verifying that the mandatory logging fields, mandatory initial diagnosis fields, diagnosis output fields has been completed comprises a step of prompting to the operator that the service request cannot be issued before the mandatory fields has been completed.
[0052] In an embodiment of the method according to the invention, the step of allocating the portion of the operator interface to a set of closure fields comprises the step of:
allocating a field for a list of open service request having matching or near matching symptoms or triggering factors of the symptoms of a problem of the service request for allowing the operator to solve similar service requests while having the service request and diagnosis steps fresh in mind.
[0054] In an embodiment of the method according to the invention, the allocation of said portion of the operator interface is shown on a graphical user interface on a computer screen and said operator input component comprises a keyboard.
[0055] In an embodiment of the method according to the invention, the input or selection values of a service request already known in the service management system are automatically discarded and thus not prompted to be input by the operator.
[0056] The object above is also achieved by providing a computer-based service provider management system comprising:
[0057] an operator interface and an input component;
[0058] a processor being configured to control operation of said system including being configured to receive input from an operator through the input component, and to run an application on said system;
[0059] said processor further being configured to receive a service request in the system from a requestor being serviced by a service provider;
[0060] said processor further being configured to allocate a portion of the operator interface to a set of predefined logging input fields comprising a set of mandatory logging input fields;
[0061] said processor further being configured to prompt an operator to input or select facts relating to the service request in the logging input fields;
[0062] said processor further being configured to verify that mandatory logging input fields has been completed before allowing the next step to be initiated;
[0063] said processor further being configured to thereafter allocate said portion of the operator interface to a set of predefined initial diagnosis input fields, said set of predefined initial diagnosis input fields comprising mandatory initial diagnosis input fields;
[0064] said processor further being configured to prompt an operator to input or select an initial diagnosis in the set of initial diagnosis input fields;
[0065] said processor further being configured to verify that the mandatory initial diagnosis input fields have been completed;
[0000] said processor further being configured to thereafter allocate said portion of the operator interface to a set of predefined diagnosis output fields, said set of predefined diagnosis output fields comprising mandatory diagnosis output fields;
[0066] said processor further being configured to prompt an operator to input or select a diagnosis output in the set of diagnosis output fields;
[0067] said processor further being configured to verify that the mandatory diagnosis output fields have been completed;
[0068] said processor further being configured to issue a service request reply comprising the diagnosis output;
[0069] said processor further being configured to thereafter allocate the portion of the operator interface to a set of closure fields comprising mandatory closure fields;
[0070] said processor further being configured to prompt an operator to input or select facts relating to closure in the set of closure fields;
[0071] said processor further being configured to verify that the mandatory closure fields has been completed;
[0072] said processor further being configured to close the service request.
[0073] The invention also relates to a computer-based service provider management system comprising a processor configured to control a set of service requests.
[0074] Also, in an embodiment of the system according to the invention, the processor is furthermore configured to categorize the service request by a service request category and configured to define a sequence of the set of predefined logging input fields based on the service request category.
[0075] Also, in an embodiment of the system according to the invention, the processor is furthermore configured to display in the central portion facts from one or more similar service requests in the same service request category during allocation of the central portion of the predefined area of the operator interface to the set of predefined logging input fields.
[0076] Also, in an embodiment of the system according to the invention, the processor is configured to prioritize the service request by a service request priority, forward the service request to a buffer list of service requests and display a service request having the highest priority in the central portion.
[0077] Also, in an embodiment of the system according to the invention, processor is configured to prioritize the service request by a service request priority, forward the service request to a buffer list of service requests and display a service request having the highest priority in the central portion.
[0078] Also, in an embodiment of the system according to the invention, the processor is configured to allocate a field for a symptom of a problem of the service request and allocate a field for a triggering factor of the symptom of the problem during allocation of the central portion to the set of predefined initial diagnosis input fields.
[0079] Also, in an embodiment of the system according to the invention, the processor furthermore is configured to receive inputs from of the operator, when the operator is inputting in fields associated with logging, initial diagnosis, diagnosis output or closure, the inputs indicating fields which are relevant to future service requests such that the indicated input from the operator may automatically enter a knowledge database.
[0080] Also, in an embodiment of the system according to the invention, the processor furthermore is configured to receive inputs from of the operator, when the operator is inputting in fields associated with logging, initial diagnosis, diagnosis output or closure, said processor being configured to receive an operator ticking off fields indicating fields which are relevant to future service requests in a ticking box associated with each field such that the ticked input from the operator may automatically enter a knowledge database.
[0081] Also, in an embodiment of the system according to the invention, the processor is configured to allocate a direct link to a knowledge database in the central portion during allocation of the central portion to a set of diagnosis output fields.
[0082] Also, in an embodiment of the system according to the invention, the processor is configured to allocate a field for a case summary during allocation of the central portion to a set of diagnosis output fields.
[0083] Also, in an embodiment of the system according to the invention, the processor is configured to allocate a field for a list of open service request having matching or near matching symptoms or triggering factors of the symptoms of a problem of the service request during allocation of the central portion to a set of closure fields.
[0084] Also, in an embodiment of the system according to the invention, the processor is configured to give access to input data from a set of fields having been recognized by a control procedure during subsequent steps.
[0085] Further objects, features, advantages and properties of the engine and method of operating an engine according to the present disclosure will become apparent from the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0086] In the following detailed portion of the present description, the invention will be explained in more detail with reference to the exemplary embodiments shown in the drawings, in which:
[0087] FIG. 1 depicts a flow-chart diagram of an embodiment of a process flow of processing a service request,
[0088] FIG. 2 a is a flow-chart diagram of a subroutine of the method shown in FIG. 1 ,
[0089] FIG. 2 b is a flow-chart diagram of a subroutine of the method shown in FIG. 1 ,
[0090] FIG. 2 c is a flow-chart diagram of a subroutine of the method shown in FIG. 1 ,
[0091] FIG. 2 d is a flow-chart diagram of a subroutine of the method shown in FIG. 1 ,
[0092] FIG. 3 is a flow-chart diagram of a subroutine,
[0093] FIG. 4 is a flow-chart diagram of a subroutine,
[0094] FIG. 5 is a schematic overview of a service provider management system,
[0095] FIG. 6 is a screen shot of an operator interface having a central portion display allocated to a set of predefined logging input fields of an electronic processing unit,
[0096] FIG. 7 is a screen shot of an operator interface having a central portion display allocated to a set of predefined initial diagnosis input fields of a processing unit,
[0097] FIG. 8 is a screen shot of an operator interface having a central portion display allocated to a set of predefined diagnosis output fields of a processing unit, and
[0098] FIG. 9 is a screen shot of an operator interface having a central portion display allocated to a set of set of closure fields of a processing unit.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0099] FIG. 1 is a flow-chart diagram of an embodiment of the present invention. FIG. 1 shows a preferred embodiment of the invention wherein the sequence created is preferably created for processing a service request using a service provider management system.
[0100] Initially a requestor transmits a service request to the service provider management system. The service request may be any type of service request managed by service provider management systems such as incident managements e.g. software failures, hardware failures, network problems etc. Incident refers to a problem in an existing IT solution. IT departments typically follow more or less the same procedures or lack of procedures when dealing with incidents irrespective of the type of incident, since the process is set out by the service provider management system of the IT or managing departments. Other types of service requests may relate to transition management i.e. the change of existing settings, hardware etc. and the deployment of such. Specific requests in transition management are requests related to release management e.g. related to release, deployment or roll-out of new software or hardware solutions. Other Specific requests in transition management are requests related to changes in standards e.g. related to release, deployment or roll-out of new software or hardware solutions according to new standards. The service request may also relate to knowledge management i.e. the request of a known knowledge item based on prior experience or the request of providing a new knowledge item to solve e.g. a recurring problem etc. The service request may also relate to request management i.e. procedures around the request of new items e.g. new hardware, new software etc. According to the method of the current invention all types of service requests are dealt with using the same generic approach, but the specific handling of different types of service requests may of course be made to depend on the specific type of service request using different subroutines or skipping steps of the method not appropriate to the specific service request.
[0101] The service request is received at an operator interface, the service provider management system typically a service provider management system application running on a computer. When the service request is received at the operator interface a set of predefined logging input fields comprising a set of mandatory logging input fields are allocated on a portion of the operator interface. By allocating a portion of the operator interface, the attention of the operator is directed towards a specific set of fields requiring input. The operator is subsequently prompted to input or select facts relating to the service request in the logging input fields. It is an essential aspect of the method, that the operator is prompted to input the facts relating to the current step in the method, to ensure that the service provider management system supports the operator in achieving a specific focus on the current step rather than a later step e.g. showing fields for inputting the solution to the problem. By allocating a portion and preferably a large and central portion of the operator interface to fields of the current logging step i.e. the logging input fields and prompting the operator to input or select facts from the service request in the logging input fields, the quality of the logging of the service request may be controlled. By adding furthermore a step verifying that mandatory logging input fields has been completed before allowing the next step to be initiated, the service provider management system is setup to ensure that the quality of the logging of the facts of the service request is always performed to a required extent. This logging subroutine also shown in FIG. 2 a shows the generic approach of the method i.e. to encourage and nudge the operator to always fill out mandatory operator input, by sequencing the subroutines in an allocation step, a prompting step and a verification step.
[0102] Following the logging subroutine (see FIG. 2 a ) are an Initial diagnosis subroutine (see FIG. 2 b ), a Diagnosis output subroutine (see FIG. 2 c ) and a Closure subroutine (see FIG. 2 d ) all having the same structure as the logging subroutine shown in FIG. 2 a of an allocation step, a prompting step and verification step. When the operator is prompted to input or select certain types of information into a set of fields allocated in a portion of the operator interface and the next set of input fields only may be allocated after the fulfillment of at least the mandatory fields, the working process of the operator may be controlled by the service provider management system and not the individual routines of the operator. This significantly enhances the quality of the handling of service requests. Furthermore, the operator may be prompted to use existing knowledge of earlier service requests based on prior input in the service provider management system. Also, the operator may be nudged to fill out non-mandatory fields to improve the quality of the handling of the service request e.g. if the service request regards a computer break down, it might be mandatory to the operator to provide the requestor with a recovery procedure to recover the computer, but the operator may be nudged to inform the requestor of improved back-up procedures to avoid data loss during future computer break downs. This type of nudge may be based on earlier and similar service requests being prompted to the operator, while being prompted to fill out any mandatory fields.
[0103] Referring now to FIG. 1 again the portion of the operator interface is subsequent to the verification of the filling of mandatory logging fields allocated to a set of predefined initial diagnosis input fields. When handling service requests of different types in a service provider management system the step of performing an initial diagnosis is very important. The initial diagnosis ensures that the type of service request is determined.
[0104] As a result of the input in the initial diagnosis fields the service request may be in some instances be treated as a quick case i.e. a service request which might be dealt with very quickly e.g. due to a prior solution to precisely the same type of service request or if the service request based on the input is found to be very minor. In such cases subsequent steps or input may be automatically input or automatically skipped to reduce time consumption of such cases. Also steps later in the method e.g. diagnosis output steps or closure steps may be automatically input or automatically skipped based on earlier input in order to handle such service requests as quick cases.
[0105] Service request management may be improved by requiring prioritization input e.g. during the initial diagnosis or diagnosis output steps. Prioritization of the service requests may in some cases be handled well by an operator performing the initial diagnosis, however, in some cases the severity of the service request are not properly assessed before an expert handles the request later in the process. Therefore, prioritization of the service requests may be performed advantageously during one or more subroutines to ensure an optimal prioritization if initial prioritizations are inadequate.
[0106] Prioritizations may be used to escalate processes or routines and operators inputting complementary information may also be viewed as a prioritizing step since the input may escalate the processes or routines based on the input.
[0107] The operator is not necessarily a person but may be a group of persons. The work flow for the operators may be such that all operators participate in the initial logging steps i.e. inputting or selecting the facts related to the service request, whereas the initial diagnosis and subsequent steps may only be dealt with by operators handling a specific type of service requests.
[0108] The operator may during the logging subroutine or the initial diagnosis subroutine accept the task of handling the service request if he feels competent. Also, the initial diagnosis may be performed by an operator executive of a group of operators and comprise a step of selecting a specific operator to handle the service request.
[0109] The basic work of handling the service request to be able to provide the requestor with a service request reply is carried out during the Diagnosis output routine. The diagnosis output fields comprise the mandatory diagnosis output fields which are essential when making a reply to the service request e.g. in a request management examples of mandatory diagnosis output fields could be: is the request of the requested item granted, is the requested item ordered, when is the expected delivery of the requested item etc. When all mandatory diagnosis output fields have been input or selected by the operator, a service request reply may be issued to the requestor.
[0110] When the service request reply has been issued to the user to the requestor the portion of the operator interface is allocated to a set of closure fields comprising mandatory closure fields. The operator is prompted to input or select facts relating to closure in the set of closure fields. This step of handling service requests is often neglected since the requestor has already received a response. In periods of high activity the operator therefore tends to neglect the closure of the handling of the service request. However, for the service provider the closure step is often essential to ensure a high level of quality in the handling of service requests and furthermore from a system point of view a time saver since future service requests are better and quicker handled if relevant details on solutions or problems are well handled in the closure steps. When the operator has input or selected at least the mandatory closure fields the mandatory closure fields are verified by the system and the service request is finally closed.
[0111] As shown in FIG. 2 a - 2 d the method shown in FIG. 1 comprise four different generic subroutines: Logging FIG. 2 a , Initial diagnosis FIG. 2 b , Diagnosis Output FIG. 2 c and Closure FIG. 2 d . Each of these subroutines comprises at least the same generic steps of allocating a set of input fields in a portion of the operator interface, prompting the operator to input and select facts and subsequently verifying that the mandatory fields have been completed. This construction of the subroutines provides a method of operating a service provider management system, where the operator is continuously prompted to have the “right mindset” of his current task. Furthermore, is he not only prompted continuously to have the “right mindset”, but the subroutine also verifies if the operator made the required input in at least the mandatory fields to ensure a high quality in the handling of service requests. The steps of consecutively going through such subroutines as shown in FIGS. 2 a - d resemble a user interface of a GPS device used in cars for determining the route of travel. The user interface keeps changing view to be exactly the extract of the route directly in front of you. The mindset of the driver is controlled by only showing the upcoming part of the route and only indicating when and where the next turn is located. In this way the mindset of the driver is controlled to focus only on the upcoming navigation and not give the next navigation command until the driver carried out the former.
[0112] Initially an operator inputs or selects a set of facts relating to the service request e.g. facts of an incident or transition. The input to the logging routine as shown in FIG. 1 is typically performed by the operator of the service provider management system, since the operator is the professional compared to the requestor. The requestor may however be forced to input the service request in a specific form to ease the work of the operator, where after the operator checks the input or selection of the requestor.
[0113] FIG. 3 shows an embodiment according to the invention wherein the step of allocating logging input fields comprises three steps in order to specifically base the input fields and the sequence of the input fields using a specific subroutine. When allocating the logging input fields according to this embodiment the operator is initially prompted to select the service request category, the selection is subsequently verified and the sequence of the logging input fields is thereafter defined based on the service request category. To allow the method of operating the service provider management system to be able to operate various categories of service requests within the same system and still maintain tailored processes and subroutines for different categories of service requests, the service request category may be required as input during the initial logging of the service request. Same approach may be used to differentiate different subcategories of service requests in any other step of the method, e.g. when the service request regards an incident management, the service request category may be chosen during the step of allocating the logging input fields to be in an “incident management” category, and then subsequently the system may require the operator to input a subcategory during the initial diagnosis step e.g. handling of a “hardware failure” subcategory and maybe even further categorized e.g. during the diagnosis output step to a more narrow subcategory e.g. “switch failure”, “hard disc failure” etc.
[0114] In some service request management systems operators inputting e.g. the initial diagnosis may not have sufficient knowledge to reach the conclusions or even the right field of the diagnosis output resolution, since these may require deeper insights into some details not available to all operators. However, to minimize non-productive time of the operators any early assessments or speculations of operators handling the initial diagnosis may be input as hypothesis input to improve the speed of the operator handling a subsequent step e.g. the diagnosis output.
[0115] As described the steps of the method according to the invention may comprise further steps to increase the quality of the handling of service requests by certain subroutines. FIG. 4 shows an embodiment according to the invention wherein the step of allocating initial diagnosis input fields comprises two steps in order to force or nudge the operator to handle the initial diagnosis by indicating the symptom associated with a problem e.g. a user requesting help with his computer, since the computer keeps crashing. The problem of the service request is evidently a computer not working optimally, the symptom is that the computer keeps crashing. Since such problem and symptom may cover a wide variety of triggering factors, the operator may already in the initial diagnosis have information about a triggering factor of the symptom e.g. the user may have provided information on a specific software program associated with the crashes or loud sound indicating hardware failures etc. If the operator is able to indicate a triggering factor already in the initial diagnosis step, the handling of the service request may be sub-optimized since a given operator handling the diagnosis output may be handed only service requests requiring the specific expertise of this operator. Same approach may be used to optimize other steps or sub routines of the method.
[0116] During an operators input of the initial diagnosis input fields a specific resolution of the output may be requested and a qualified resolution may be searched to accommodate the request. Iterations may be required to achieve the requested specific resolution if the accessible resolution is inadequate e.g. maybe the generic problem was solved earlier, but the specific problem is different and must be handled differently than the accessible resolution. In such cases the operator is then required to input a qualified resolution to the specific problem or in case the problem is not solvable inputs a “no-resolution”, which may be communicated back to the requestor of the service request. This approach may furthermore be used to set up a well-organized hierarchy of qualified resolutions, which may be used systematically in future handlings of service requests.
[0117] FIG. 5 is a schematic overview of a service provider management system comprising four different service request categories i.e. incident, transition, knowledge and request managements. These are not to be considered limiting to the scope of the invention, but are examples of typical categories of service requests handled in service provider management systems. Even more categories may be handled using the same method and service provider management system. Since the operator interface is controlled to primarily comprise fields intended to be handled by the operator in that particular part of the process, the operator is not affected by the system handling a wide variety of service request categories. If the operator is not well suited to fill out the required input he may forward it to the relevant operators or send it back for re-categorization. In this way the daily work of the operator may also be more convenient since stressful tasks relating to the handling of service requests outside the competences of the operator may be more or less avoided.
[0118] FIGS. 6-9 shows a series of screen shots of an operator interface having a central portion allocated to specific fields of interest during the process thereby controlling the operator to fill in the needed information to ensure a good, thorough and consistent processing of service requests by a service provider and a controlled collection of the knowledge build-up by earlier inquiries.
[0119] In some methods of operating service request management systems specific steps of the method may involve the requestor to input additional information required to solve certain issues with respect to the service request.
[0120] Reminders may be used in the method or systems according to the invention to remind operators or requestors to input a certain mandatory or non-mandatory input. Especially mandatory input may be ensured be specific subroutines reminding of missing input.
[0121] In some embodiments of the invention the requestor may act as operator.
[0122] The term “comprising” as used in the claims does not exclude other elements or steps. The term “a” or “an” as used in the claims does not exclude a plurality. The single processor, device or other unit may fulfill the functions of several means recited in the claims.
[0123] The reference signs used in the claims shall not be construed as limiting the scope.
[0124] Although the present invention has been described in detail for purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the scope of the invention.
[0125] While the preferred embodiments of the devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the inventions. The elements of the various embodiments may be incorporated into each of the other species to obtain the benefits of those elements in combination with such other species, and the various beneficial features may be employed in embodiments alone or in combination with each other. Other embodiments and configurations may be devised without departing from the spirit of the inventions and the scope of the appended claims.
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A method of operating service provider management systems using a content-control and nudging based process to ensure quality and facilitate knowledge build-up and a computer-based service provider management system configured to support the method.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon U.S. provisional patent application No. 61/176,441, filed on May 7, 2009, the priority of which is claimed.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a system and method of using same to seal a well bore such that the production of hydrocarbons may be safely controlled. More specifically, the invention relates to a multi-piece stacked sealing system and method for using same to seal the annulus between a production casing and a tubing hanger.
[0004] 2. Description of the Related Art
[0005] A typical subsea wellhead assembly includes a wellhead housing installed at the sea floor. With a drilling blowout preventer (BOP) stack installed on the wellhead housing, the well bore is drilled while successively installing concentric casing strings in the well bore. Typically, each successive casing string is cemented at its lower end and includes a casing hanger sealed with a mechanical seal assembly at its upper end in the wellhead housing.
[0006] In order to produce the cased well, a production tubing string and tubing hanger are typically run into the well bore through the BOP stack and the tubing hanger is landed, sealed and locked in the wellhead housing and/or casing hanger. Upon sealing the bore(s) extending through the tubing hanger, the BOP stack is removed and a Christmas tree is lowered onto the wellhead housing. A Christmas tree is an oilfield term understood to include the control valves and chokes assembled at the top of a well to control the flow of oil and gas. It is vitally important to the operation and safety of the well that the proper connections are remotely formed between the Christmas tree, the wellhead housing, and the tubing hanger.
[0007] In a conventional completed well system, the Christmas tree is connected to the top of the wellhead housing over the tubing hanger. The tubing hanger supports at least one production tubing string which extends into the well bore. The tubing hanger provides a production bore within the tubing string and a conduit that communicates with the annulus surrounding the tubing string and inside the innermost or production casing string. In addition, the tubing hanger comprises at least one vertical production bore for communicating fluid between the tubing string and a corresponding production bore in the Christmas tree, and typically at least one vertical annulus bore for communicating fluid between the tubing annulus and a corresponding annulus bore in the Christmas tree. The tubing hanger may additionally include one or more service and control conduits for communicating control fluids and well chemicals through the tubing hanger or electrical power to devices or positions located in or below the tubing hanger.
[0008] A tubing hanger conventionally is sealed and rigidly locked into the wellhead housing or component in which it is landed. In a well having a conventional Christmas tree, the tubing hanger is landed in the wellhead housing. The tubing hanger typically includes an integral locking mechanism which, when activated, secures the tubing hanger to the wellhead housing or a profile in the casing hanger. The locking mechanism ensures that any subsequent pressure from within the well acting on the tubing hanger will not cause the tubing hanger to lift from the wellhead housing thereby resulting in an unsafe condition.
[0009] There are a limited number of subsea wellhead equipment manufacturers worldwide. Currently, the primary manufacturers of subsea wellhead housings are ABB Vetco Gray, Cooper Cameron Corp., Dril-Quip, FMC, and Kvaerner. Each of the primary manufacturers has its own proprietary wellhead housing and casing hanger designs, dimensions, and details. Quite frequently, a well is completed on Manufacturer A's wellhead housing and casing hangers using a tubing hanger and/or Christmas tree from Manufacturer B. However, since Manufacturer A's housing and casing hanger design are proprietary, Manufacturer B may not be able to connect its Christmas tree to Manufacturer A's housing without a license from Manufacturer A at a fee in order to design Manufacturer B's equipment to properly interconnect and mate with Manufacturer A's wellhead housing and casing hanger. This results in a substantial amount of additional engineering and costs or additional equipment (such as a tubing spool) when electing to purchase Manufacturer B's equipment for use with Manufacturer A's wellhead housing. Since each wellhead housing/system manufacturer has multiple models of housings and casing hangers with different proprietary details, it is not practical or economical for other manufacturers to build up an inventory of equipment for installation on other manufacturers' wellhead equipment. In addition to the added costs, it also increases, the delivery time which is often vitally important to the well owner.
[0010] A tubing hanger assembly adapted for positioning in the wellhead housing independently of any proprietary details of the wellhead housing has recently been disclosed by Broussard in U.S. Pat. No. 7,419,001, which is incorporated herein by reference. The tubing hanger suspension assembly disclosed in U.S. Pat. No. 7,419,001 includes a tubing hanger housing which is positioned in the wellhead housing and further includes a sealing and lockdown mechanism capable of providing sealing and load support of the production tubing in the production casing string.
[0011] FIG. 1 shows a universal tubing hanger suspension assembly 80 according to a preferred embodiment of U.S. Pat. No. 7,419,001. The tubing hanger suspension assembly 80 includes a string of production tubing 122 connected to a tubing hanger housing 124 . The production tubing 122 defines a production tubing bore 122 a extending axially through the tubing 122 . The tubing hanger housing 124 includes production bore 124 a in fluid communication with the production tubing bore 122 a . The production bore 124 a extends substantially vertically through the tubing hanger housing 124 . The production tubing string 122 typically extends down to the production zone Z. The production tubing string 122 includes a subsurface safety valve 126 at a desired depth with the well bore B. The tubing hanger housing 124 also includes an annulus passageway 124 b extending through the tubing housing hanger 124 . Included in the tubing housing assembly 124 is an annulus isolation valve 128 arranged and designed to seal and close off the annulus passageway 124 b.
[0012] The universal tubing hanger suspension assembly 80 includes a tubing hanger lower assembly 82 at a lower end of the tubing hanger housing 124 . The lower assembly 82 may be connected to or integral with the tubing hanger housing 124 . The lower assembly 82 includes a sealing and lockdown assembly 134 . The lower assembly 82 is preferably a tubular member having a throughbore, such as a pipe or a mandrel having a bore therethrough. The tubing hanger lower assembly 82 extends around the production tubing string 122 with a production annulus 132 a defined therebetween. While production string 122 preferably has a length such that its lower end extends approximately to the production zone Z, the tubing hanger lower assembly 82 preferably has a length substantially less than the length of the tubing string 122 .
[0013] The sealing and lockdown assembly 134 is carried by the tubing hanger lower member 82 . The sealing/lockdown assembly 134 is located near the lower end of the tubing hanger lower member 82 . An enlarged view of the sealing/lockdown assembly 134 is shown in FIG. 1A . The sealing/lockdown assembly 134 includes an enlarged outside diameter tubular portion 136 which is slightly less than the inside diameter of the production casing 118 . The sealing/lockdown assembly 134 includes a sealing apparatus 138 and a movement prevention locking apparatus or lockdown apparatus 140 . The sealing apparatus 138 and the lockdown apparatus 140 may be contained within a unitary assembly or may be separate assemblies. In wells having a subsurface safety valve 126 ( FIG. 1 ), the sealing apparatus 138 is positioned in the casing string 118 above the subsurface safety valve 126 and the lockdown apparatus 140 will also be above the subsurface safety valve 126 .
[0014] The lockdown apparatus 140 includes elements or slips, which may be metallic or nonmetallic, adapted to engage the interior of the production casing 118 . When engaged, the lockdown apparatus 140 engages the interior of the casing 118 and “fixes” or prevents axial (i.e., vertical or up and down) movement of the tubing hanger suspension assembly 80 ( FIG. 1 ) relative to the production casing 118 .
[0015] The sealing apparatus 138 includes a sealing element, which may be made of elastomers or other elastic materials (including composites) or a metal seal, adapted to form an annular seal between the production casing 118 and the tubular portion 136 , as for example, by compression. The sealing apparatus 138 and the lockdown apparatus 140 may be independently activated or jointly activated. As shown in FIG. 1A , the activation and de-activation of the lockdown apparatus 140 and the sealing apparatus 138 is hydraulically controlled through ports 142 a and 142 b . However, the activation and de-activation may also be accomplished electronically, mechanically, or electrically.
[0016] The sealing and lockdown assembly 134 is activated, preferably hydraulically, via the hydraulic control lines to force the lockdown apparatus 140 into tight locked engagement with the production casing 118 . The engaged lockdown apparatus 140 prevents or substantially prevents relative vertical movement between the lower tubular member 82 and the production casing 118 . The sealing and lockdown assembly 134 may comprise a set of slips having metal elements which grip the production casing 118 . An elastomeric or other elastic-type seal is compressed by the set slips to form a fluid-tight seal. Typically, the sealing and lockdown assembly 134 is a modified packer assembly of the type conventionally used in wells to isolate production zones, etc. However, disclosed hereinafter are implementations of a multi-piece stacked sealing system designed to be used in place of the sealing apparatus 138 disclosed in U.S. Pat. No. 7,419,001, to compliment the tubing hanger lockdown and seal assembly 134 disclosed therein, or to provide independent annular sealing between tubulars, i.e., in a well bore. U.S. provisional patent application No. 61/176,441, upon which this application is based, is incorporated herein by reference.
BRIEF SUMMARY OF THE INVENTION
[0017] A multi-piece stacked sealing system (i.e., a multi-piece stacked seal system) arranged and designed to seal the annulus between tubular members, and more preferably, between production casing (i.e., outer tubular) and a tubing hanger (i.e., inner tubular) is disclosed. The system is preferably carried by a tubing hanger assembly and can either be a stand alone system or comprise a part of a sealing and locking mechanism assembly typically associated with a tubing hanger assembly. However, the system may also be used to seal annular spaces between a variety of tubulars. In a preferred implementation, the system comprises a plurality of rigid members (i.e., tapered rings composed of a rigid material), a plurality of elastic members (i.e., tapered rings composed of an elastic or elastomeric material), an upper support ring, and a lower support ring, each positioned around the circumference of the tubing hanger assembly. The plurality of rigid members are preferably stacked between the upper and lower support rings with the plurality of elastic members interposed therebetween such that the tapered surfaces of the rigid members, the elastic members, and the upper and lower support rings compliment each other.
[0018] The system is activated by applying an axial downward force on the upper support ring by several methods including, but not limited to, hydraulic, mechanical, electronic, or electrical methods. This compressive force in turn compresses the spaces between the rigid members (i.e., rigid tapered rings) stacked around the tubing hanger and further compresses the elastic members (i.e., elastic tapered rings) disposed there in between. Compression of the elastic members causes their temporary deformation and forces the elastic members into sealing contact with the inner wall of the production casing, thereby sealing the annulus between the tubing hanger and the production casing. Once compressed, the rigid members are physically stopped by each other (i.e., they will not travel past each other), therefore, the system cannot be over-compressed. Similarly, the compressed elastic members are prevented from being extruded through any space between the inner wall of the production casing and the rigid members during activation/compression of the system by the counteracting compression forces that are imparted to the elastic members disposed between adjacent rigid members. De-activation of the system may be accomplished by removing or reducing the downward axial force applied to the upper support ring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] By way of illustration and not limitation, the invention is described in detail hereinafter on the basis of the implementations represented in the accompanying figures, in which:
[0020] FIG. 1 is a schematic sectional elevation view illustrating a universal tubing hanger suspension assembly comprising a tubing hanger lower assembly which carries a sealing and lockdown assembly;
[0021] FIG. 1A is an enlarged schematic sectional elevation view of the sealing and lockdown assembly of the tubing hanger suspension assembly of FIG. 1 ;
[0022] FIG. 2 is an enlarged schematic sectional elevation view illustrating a preferred implementation of the multi-piece stacked sealing system, in an non-actuated or non-sealing state, carried by the tubing hanger lower assembly and disposed between the tubing hanger lower assembly and production tubing;
[0023] FIG. 3 is an enlarged schematic sectional elevation view illustrating a preferred implementation of the multi-piece stacked sealing system of FIG. 2 in which the multi-piece stacked sealing system has been actuated to seal the annulus between the tubing hanger lower assembly and the production tubing; and
[0024] FIG. 4 illustrates an enlarged schematic sectional view of the multi-piece stacked sealing system of FIG. 2 illustrating the elastic member disposed adjacent to a top rigid member.
DETAILED DESCRIPTION OF THE INVENTION
[0025] As generally shown in FIG. 2 , a preferred implementation of the invention is a multi-piece stacked sealing system 10 (i.e., a multi-piece stacked seal system) carried by a tubing hanger lower assembly 82 of a universal tubing hanger suspension assembly 80 ( FIG. 1 ). The multi-piece stacked sealing system 10 is preferably arranged and designed to seal the annulus between the tubing hanger lower assembly 82 and the production casing 118 . The multi-piece stacked sealing system 10 preferably comprises a plurality of rigid rings or members 20 , a plurality of elastic rings or members 40 , 44 , 46 , coiled springs 60 , 62 , an upper support ring 22 carrying a U-cup seal 70 , and a lower support ring 24 carrying a U-cup seal 70 . The plurality of rigid members 20 , the upper support ring 22 , and the lower support ring 24 are preferably composed of a metallic material such as, but not limited to, steel; however various rigid nonmetallic and composite/mixed composition materials known to those of skill in the art may also be used.
[0026] Each of the rigid members 20 is a ring-like structure designed with an inner wall 26 having an inner diameter slightly larger than the outer diameter of the tubing hanger lower assembly 82 such that the rigid members 20 may be carried by the tubing hanger lower assembly 82 . The rigid members 20 preferably have an outer diameter slightly smaller than the inner diameter of the production casing 118 ; however, the outer diameter of the rigid members 20 may be designed to contact the inner wall 92 of the production casing 118 regardless of whether the multi-piece stacked sealing system 10 is actuated or as a direct result of the actuation of the multi-piece stacked sealing system 10 . Rigid members 20 are preferably designed such that in cross-section, as shown in FIG. 2 , the members 20 have a generally triangular shape (i.e., tapered on its top (upper) and bottom (lower) sides to form an outwardly distal apex/vertex) with each vertex preferably being flat (i.e., not pointed).
[0027] The rigid members 20 are preferably stacked or disposed around the tubing hanger lower assembly 82 between an upper support ring 22 and a lower support ring 24 such that the inner wall 26 of the rigid members 20 is disposed adjacent to the outer surface 86 of the tubing hanger lower assembly 82 . The rigid members 20 are preferably designed to move/slide axially about the outer surface 86 of the tubing hanger lower assembly 82 . As previously discussed, the rigid members 20 have a generally triangular shape in cross-section and it is preferred to have the rigid members 20 oriented about the tubing hanger lower assembly 82 such that the apex 28 of this generally triangular shape in cross section is disposed towards the production casing 118 . In other words, rigid rings or members 20 each have a top (upper) surface and a bottom (lower) surface that are tapered toward a common circular (i.e., circumferential) apex 28 . When viewed in cross-section, this apex 28 may have a shape that is pointed (not shown) or flat ( FIGS. 2-4 ). There are two rigid members 20 shown in FIG. 2 , however, additional rigid members (not shown) may be stacked above or below but between the upper 22 and lower 24 support rings. A space 30 is preferably disposed between each of the rigid members 20 and between the rigid members 20 and the upper 22 and lower 24 support rings.
[0028] The upper support ring 22 , positioned around the circumference of the tubing hanger lower assembly 82 (i.e., inner tubular), has a U-cup seal 70 disposed in its inner wall 32 ( FIG. 4 ), which is arranged and designed to seal between the upper support ring 22 and the tubing hanger lower assembly 82 . Similarly, the lower support ring 24 , also positioned around the circumference of the tubing hanger lower assembly 82 (i.e., inner tubular), has a U-cup seal 70 disposed in its inner wall 34 , which is arranged and designed to seal between the lower support ring 24 and the tubing hanger lower assembly 82 . These top and bottom [ ]-cup seals 70 are preferably interchangeable and replaceable. While a U-cup seal is one preferred type of seal, other types of seals well known to those skilled in the art, including but not limited to O-ring and polypack seals, may also be preferably used. When viewed in cross-section ( FIGS. 2-3 ), the upper support ring 22 preferably has a tapered lower surface and the lower support ring 24 preferably has a tapered upper surface. As viewed in cross-section, the respective vertices of the upper and lower support rings, which are adjacent to the outer surface 86 of the tubing hanger lower assembly 82 and elastic member 44 , 46 , are preferably flat (i.e., not pointed) so as to compliment the vertices of the elastic members 44 , 46 .
[0029] The elastic members 40 , 44 , 46 are preferably composed of a thermoplastic elastomer such as, but not limited to, an engineering thermoplastic elastomer. The thermoplastic elastomer is selected such that: (1) it is rigid under no axial loading and has a durometer between Shore 30D to 82D, more preferably between Shore 40D and 60D and most preferably between Shore 52D to 55D, and (2) under axial loading greater than approximately 50,000 lbf, but more preferably under axial loading greater than approximately 15,000 lbf, it becomes more fluid-like and capable of being deformed. Engineering thermoplastic elastomers composed, at least in part, of polyester, such as DuPont Hytrel® (thermoplastic polyester elastomer), and more specifically Dupont Hytrel® 5555HS, are a preferred material for constructing the elastic members 40 , 44 , 46 . However, other thermoplastic polyester elastomers may also be used. A preferred material may also have some or all of the following characteristics:
[0000] Characteristic Range Hardness (Shore D) 40 to 72 Specific Gravity 1.17 to 1.25 T m (° C.) 170 to 232 Vicat Softening Point 112 to 203 Tensile Strength (MPa) 30 to 52 Flexural Modulus (MPa) 48 to 517 Elongation (%) 420 to 560
An advantage of using a preferred elastomeric material is that the multi-piece stacked sealing system 10 may be activated or energized to deform the elastic members 40 , 44 , 46 at a much lower axial compression force.
[0030] As shown in FIG. 2 , the elastic members 40 , 44 , 46 are ring-like structures designed with an outer wall 42 having an outer diameter slightly smaller than the inner diameter of the inner wall 92 of the production casing 118 . The elastic members 40 , 44 , 46 are preferably designed such that in cross-section, as shown in FIG. 2 , the elastic members 40 , 44 , 46 have a generally triangular shape (i.e., tapered on its top and bottom sides to form an inwardly distal apex). It is preferred to have the elastic members 40 , 44 , 46 oriented about the tubing hanger lower assembly 82 such that the apex 48 of this generally triangular shape in cross section is disposed towards the tubing hanger lower assembly 82 . In other words, elastic rings or members 40 , 44 , 46 each have a top (upper) surface and a bottom (lower) surface that are tapered toward a common circular (i.e., circumferential) apex 48 . When viewed in cross-section, this apex 48 may have a shape that is pointed (not shown) or flat ( FIGS. 2-4 ). While the elastic members 40 , 44 , 46 are interposed to compliment the tapered surfaces of the rigid members 20 and the upper 22 and lower 24 support rings, the elastic members 40 , 44 , 46 are preferably designed not to be flush with the tubing hanger lower assembly 82 so as to provide the space 30 previously described. As shown, the elastic members 40 , 44 , 46 are designed to be interposed between rigid members 20 and between the rigid members 20 and the upper 22 and lower 24 support rings, such that the elastic members 40 , 44 , 46 are also carried by the tubing hanger lower assembly 82 . Preferably, the plurality of rigid members 20 are stacked between the upper 22 and lower 24 support rings (and around the circumference of the tubing hanger) with the plurality of elastic members 40 , 44 , 46 interposed therebetween such that the tapered surfaces of the rigid members 20 and the elastic members 40 , 44 , 46 compliment each other.
[0031] The ring-like elastic member 44 disposed adjacent to the upper support ring 22 has an upper spring 60 that is shaped in the form of a ring and disposed therein preferably within a notch or recessed groove 64 formed in an upper most surface 52 . Similarly, the ring-like elastic member 46 disposed adjacent to the lower support ring 24 has a lower spring 62 that is shaped in the form of a ring and disposed therein preferably within a notch or recessed groove 66 formed in a lower most surface 54 . An enlarged schematic sectional elevation view of the elastic member 44 disposed adjacent to the upper support ring 22 is shown in FIG. 4 . The notch 64 formed in the upper most surface 52 of the elastic member 44 provides integral structures to elastic member 44 , similar to lips, on either side of the notch 64 . As shown in FIG. 4 , the integral structure of the elastic member 44 closest to the tubing hanger lower assembly 82 forms an upper inner lip 58 and the integral structure of the elastic member 44 closest to the production casing 118 forms an upper outer lip 56 . An unactuated, ring-shaped spring 60 is disposed in the notch 64 . The upper spring 60 is designed to move radially outwardly in response to pressure applied axially to the upper support ring 22 . The outward radial movement of the spring 60 is further designed to apply pressure and thereby move the upper outer lip 56 radially outwardly and into sealing contact with the inner wall 92 of production casing 118 . While a close-up illustration of the elastic member 46 disposed adjacent to the lower support ring 24 is not shown, one skilled in the art will recognize that it would appear similar to that shown in FIG. 4 except flipped top to bottom.
[0032] In a preferred method of using the invention, a universal tubing hanger suspension assembly 80 ( FIG. 1 ) is placed within the wellhead housing such that the multi-piece stacked sealing system 10 carried by the tubing hanger lower assembly 82 is positioned proximate to the portion of the production tubing 118 (i.e., outer tubular) to be annularly sealed. FIG. 2 shows the multi-piece stacked sealing system 10 prior to activation and FIG. 3 shows the multi-piece stacked sealing system 10 after activation. The multi-piece stacked sealing system 10 may be activated/actuated hydraulically by applying hydraulic fluid into a cavity (not shown) arranged and designed to exert a downward axial force against the upper support ring 22 , e.g., through downward axial movement of ring-like member 76 . As shown in FIGS. 2-4 , ring-like member 76 is representative of a hydraulically-actuated piston-type device. Such hydraulic mechanisms and actions are well known to those skilled in the art and several hydraulic actuators are known that may be equally employed to activate/actuate the multi-piece stacked sealing system 10 . Those skilled in the art will readily recognize that activation/actuation may also be effected electronically, mechanically, or electrically through a variety of methods and devices arranged and designed to apply a downward axial force upon the multi-piece stacked sealing system 10 .
[0033] Starting with FIG. 2 , upon activation/actuation, the upper support ring 22 of the multi-piece stacked sealing system 10 is forced downwardly in an axial direction by the downward axial movement of ring-like member 76 toward the rigid members 20 and the lower support ring 24 , thereby compressing the upper support ring 22 , the rigid members 20 , and the lower support ring 24 together. The compression of these members 20 and rings 22 , 24 closes the spaces 30 therebetween such that they contact each other but are positively stopped by each other (i.e., there is no over travel). Thus, the multi-piece stacked sealing system 10 is preferably activated or energized (and unlocked) by axially moved internal components but the system 10 cannot be over compressed. It should be noted that lower support ring 24 is preferably designed to move/slide axially about the outer surface 86 of the tubing hanger lower assembly 82 . However, as shown in FIGS. 2 and 3 , the downward axial movement of lower support ring 24 is stopped by tubing hanger lower assembly 82 . This permits the members 20 and rings 22 , 24 to be compressed together via the downward axial force applied to upper support ring 22 , e.g., by ring-like member 76 . Alternatively, but not shown, the downward axial movement of lower support ring 24 may be stopped by an actuated element or slip of lockdown apparatus 140 , such as that shown in and described in relation to FIGS. 1 and 1A . Further still, lower support ring 24 may be coupled to tubing hanger lower assembly 82 so as to prevent any downward axial movement.
[0034] As shown in FIG. 3 , the compression of these member(s) 20 and rings 22 , 24 also compresses the plurality of elastic members 40 , 44 , 46 interposed therebetween, which in turn forces these elastic members 40 , 44 , 46 to deform into sealing contact with the inner wall 92 of the production casing 118 . This deformation and general outward radial movement of elastic members 40 , 44 , 46 , caused by their compression between the tapered surfaces of the rigid members 20 (and upper/lower support rings 22 , 24 ), creates the spaces 38 as shown in FIG. 3 . The composition of the elastic members 40 , 44 , 46 is selected to ensure deformation of the elastic members 40 , 44 , 46 into sealing contact with the inner wall 92 of production casing 118 , including production casing having an irregular surface, such as one marred, gashed, pitted, or out of round. The elastic member 44 adjacent to the upper support ring 22 is prevented from being extruded downwardly between the inner wall 92 of production casing 118 and the rigid member 20 by an equal or near equal counter force provided by the compressed, adjacently positioned elastic member 40 . Similarly, the elastic member 46 adjacent to the lower support ring 24 is prevented from being extruded upwardly between the inner wall 92 of production casing 118 and the rigid member 20 by an equal or near equal counter force provided by the compressed, adjacently positioned elastic member 40 . While FIGS. 2 and 3 show only one elastic member 40 between rigid members 20 , additional elastic members 40 could be positioned between additional rigid members 20 in a similar alternating arrangement. The compression of these additional elastic members (not shown) would similarly prevent, by providing an equal or near equal counter force, the extrusion of adjacently positioned elastic members between the inner wall 92 of production casing 118 and the additional rigid members (not shown).
[0035] As best shown in FIG. 3 , compression of elastic member 44 by upper support ring 22 causes upper inner lip 58 ( FIG. 4 ) to compress and move upper spring 60 radially outward toward the inner wall 92 of the production casing 118 . The radial outward movement of spring 60 forces upper outer lip 56 ( FIG. 4 ) into sealing contact with the inner wall 92 of the production casing 118 . An advantage of the spring 60 is that it stores the kinetic energy of the axial compression of multi-piece stacked sealing system 10 ; thereby retaining the compression force against upper outer lip 56 ( FIG. 4 ) in sealing contact with the inner wall 92 and preventing or minimizing further deformation or creep of the elastic member 44 . As best shown in FIG. 3 , compression of elastic member 46 by lower support ring 24 causes lower inner lip 59 to compress and move lower spring 62 radially outward toward the inner wall 92 of the production casing 118 . The radial outward movement of spring 62 forces lower outer lip 57 into sealing contact with the inner wall 92 of the production casing 118 . The spring 62 also retains the compression force against lower outer lip 57 in sealing contact with the inner wall 92 ; thereby preventing or minimizing further deformation or creep of the elastic member 46 . As will be readily apparent to one skilled in the art, when additional axial pressure is applied to the multi-piece stacked sealing system 10 either upwardly or downwardly, the compression of the elastic members 40 , 44 , 46 between the inner wall 92 of the production casing 118 and the tubing hanger lower assembly 82 increases, thereby improving the leak resistance of the multi-piece stacked sealing system 10 .
[0036] As will be readily recognized by those skilled in the art, deactivation or unlocking of the multi-piece stacked sealing system 10 is accomplished by removing the downward axial force caused to be exerted upon the upper support ring 22 , e.g., by member 76 . The absence of this downward axial force will allow the elastic members 40 , 44 , 46 to resume their former shape, thereby expanding the rigid members 20 (and upper support ring 22 ) axially. While the previous implementations generally describe the activation/actuation of the system 10 using an axial downward force applied to the upper support ring 22 with the lower support ring 24 held stationary, an alternative implementation may activate/actuate the system 10 using an axial upward force applied to the lower support ring 24 with the upper support ring 22 held stationary. Based on the disclosure herein, such alternative implementation is within the knowledge of those skilled in the art.
[0037] The Abstract of the disclosure is written solely for providing the United States Patent and Trademark Office and the public at large with a means by which to determine quickly from a cursory inspection the nature and gist of the technical disclosure, and it represents solely a preferred implementation and is not indicative of the nature of the invention as a whole.
[0038] While some implementations of the invention have been illustrated in detail, the invention is not limited to the implementations shown; modifications and adaptations of the above implementations may occur to those skilled in the art. Such modifications and adaptations are in the spirit and scope of the invention as set forth in the claims:
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Subsea wells have a variety of proprietary well head configurations that require sophisticated locking and sealing profiles that allow the well bore to be sealed off and the production of hydrocarbons to be safely controlled. A universal tubing hanger and lockdown assembly uses a sealing apparatus to annularly seal the well bore. When compressed, a multi-piece stacked sealing system employs rigid and elastic members to seal the well bore annulus in both the top-down and bottom-up directions. Top-down pressure containment is needed for appropriate well system testing and bottom-up pressure containment is necessary to control the internal pressure of the well.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to lifting devices and more particularly to devices employed in removing and installing rotating conveyor rolls in a continuously operating conveying system.
2. Description of the Prior Art
In the production of glass, it is customary to produce a continuous ribbon of glass from a molten mass and pass this plastic ribbon through an annealing lehr which operates continuously with a melting furnace producing the molten mass of glass. It is well known that in passing the continuous glass ribbon through the lehr, that it is conveyed on rolls that are commonly driven from a continuously operating drive train. Customarily, each roll in the conveying system is driven by a worm gear connected to a mechanical line shaft extending the length of the lehr. Since the lehr must be operated continuously in producing the glass ribbon, the replacement of defective conveyor rolls, for example those requiring grinding, is a problem as they are heavy and of large size and must be replaced while the lehr is operating.
Heretofore, a defective conveyor roll was replaced by first inserting a bar into the driven open end of the roll, which is normally hollow, and a jack having an appropriate extension was placed on the floor in position to engage the bar. The jack was then raised to lift the bar, and thus the end of the conveyor roll, just enough to remove a shim from beneath the bearing housing journalling the end of the roll. The jack was then lowered which, of course, disengaged the worm wheel from the rotating worm on the line shaft, and the disconnected conveyor roll was removed from the conveying system of the lehr. Of course, a conveyor roll was installed in the conveying system by reversing the above-described procedure.
However, this procedure has not been entirely satisfactory in that damage to the drive train may occur because of the small amount of clearance provided between the worm wheel and the driving worm and the inability to precisely lift the bar and firmly hold the end of the conveyor roll with a floor supported jack. In accordance with the present invention, the movement of the end of the roll having a worm wheel can be precisely controlled and the end of the conveyor roll firmly held to prevent damage to the drive train while it is in operation.
SUMMARY OF THE INVENTION
Generally stated, the present invention contemplates providing devices for lifting and lowering the bearing housings mounting the bearings journalling the driven ends of rotating conveyor rolls wherein shims disposed between the bearing houses and a stationary surface support the rolls in a common planar position. The devices are supported from a stationary surface and have portions engaging the bearing housings, which portions are precisely lifted and lowered by rotating threaded lifting members, thus permitting the shims to be inserted and/or removed from beneath the bearing housings. The ends of the conveyor rolls are firmly held by assuring that a certain amount of force is maintained on the bearing housings. This is accomplished by tightening or loosening the bearing housing bolts while simultaneously operating the lifting member to snugly hold the bearing housings relative to the stationary surface.
OBJECTS AND ADVANTAGES
An object of this invention is to provide a lifting and lowering device whose movements can be precisely controlled.
Another object of this invention is to provide a lifting and lowering device that snugly engages the members being moved.
Yet another object of this invention is to provide a lifting and lowering device that is simple in construction, easy to manufacture and efficient in operation.
Other objects and advantages will become more apparent during the course of the following description, when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, wherein like numerals are employed to designate like parts throughout the same:
FIG. 1 is a fragmentary perspective view of a glass annealing lehr and its conveying system wherein the present invention is employed;
FIG. 2 is an enlarged perspective view, taken in the direction of arrow A in FIG. 1, of a lifting device constructed in accordance with the present invention;
FIG. 3 is an enlarged, front elevational view of the lifting device illustrated in FIGS. 1 and 2 and shown in its lowermost position;
FIG. 4 is an enlarged view similar to FIG. 3 but with the lifting device shown in its raised position;
FIG. 5 is an enlarged perspective view, taken in the direction of arrow B in FIG. 1, of another embodiment of a lifting device constructed in accordance with the invention;
FIG. 6 is an enlarged perspective view of the lifting device illustrated in FIG. 5;
FIG. 7 is an enlarged front elevational view of the lifting device as illustrated in FIG. 5; and
FIG. 8 is a fragmentary cross sectional view taken substantially along line 8--8 of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 there is illustrated a portion of an annealing lehr 10 customarily employed in the manufacture of a continuous ribbon of glass R. The lehr 10 generally comprises a closed refractory structure (not shown) and a conveying system comprising a plurality of longitudinally spaced driven conveyor rolls 11 extending transversely of the closed structure for conveying the glass ribbon R therethrough. One end 12 of each roll 11 projects through a sidewall 13 forming part of the closed structure. The end 12 of each roll 11 is journalled in a bearing 14 mounted in a housing 15 affixed by a bolt 16 (see FIGS. 3, 4 and 7) to a horizontally disposed rail 17 extending longitudinally along the length of the lehr 10, which rail 17 is supported in spaced relation above the floor 18 on upstanding legs 19. A shim 20 located beneath each of the bearing housings 15 supports the end 12 and thus the surface of each roll 11 in a spaced, planar position above the rail 17. Each shim 20 (see FIG. 2) is provided with an open end slot 21 which surrounds the bolts 16 so that it may be removed or installed beneath the bearing housing 15 without removing the bolt 16 from the bearing housing 15 for a purpose to be described hereinafter.
As best illustrated in FIG. 1, the conveyor rolls 11 are commonly driven by a mechanical line shaft 22 extending longitudinally along the length of the lehr 10 which is drivingly connected to a motor (not shown). More particularly, the end 12 of each roll 11 is provided with a driven worm wheel 23 which meshes with a worm 24 affixed to the driven line shaft 22 for rotation therewith. The line shaft 22, of course, is supported in spaced relation above the ends 12 of the rolls 11 so as to provide the proper clearance between the meshing worm wheel 23 and the worm 24. Specifically, the free end 25 of the line shaft 22 is journalled in a pair of bearings 26, one on each side of the worm 24, which are mounted in a saddle-type supporting bracket 27 secured to the rail 17 by bolts 28. Intermediate sections of the line shaft 22 are journalled in coupling-type bearings 29 (only one shown) supported by U-shaped brackets 30 also secured to the rail 17 by bolts 28.
The present invention contemplates providing two types of lifting devices, each designated in its entirety by the reference numerals 31a and 31b, by which an operator can precisely lift and firmly hold the end 12 of any conveyor roll 11 in an operating conveying system to remove and/or replace the roll 11 therein. Briefly, each lifting device 31a and 31b generally comprises a rigid member having portions for engaging the bearing housing 15 and means for raising and lowering the engaging portions whereby an operator can remove or place the shim 20 beneath the bearing housing 15 to engage or disengage the worm wheel 23 with the worm 24.
In the embodiment of the invention illustrated in FIGS. 2, 3 and 4 and shown in a working position in FIG. 1, the lifting device 31a is constructed to be used with any intermediate conveyor roll 11. The lifting device 31a includes a U-shaped bracket 32 that is adapted to surround the bearing housing 15, and wherein the legs of the bracket 32 have portions 33 engaging the bearing housing 15. More specifically, each of the legs of the U-shaped bracket 32 comprises an angle member 34 having a horizontal flange portion 35 and an upstanding portion 36 which are rigidly connected together at one of their ends by a tie bar 37. The inner top edges of the upstanding portions 36 are chamfered to provide the engaging portions 33 previously described. Each horizontal flange portion 35 of the angle members 34 is provided with at least one central aperture 38 for rotatably receiving a jack screw 39.
When an intermediate conveyor roll 11 is to be removed from the conveying system, for example, the device 31a is placed on the rail 17 so that it surrounds the bearing housing 15 with its tie bar 37 adjacent the rear of the housing 15 (see FIGS. 1 and 3). The jacking screws 39 on each side of the bracket 30 are then rotated to first raise the rigid U-shaped bracket 30 and its chamfered engaging portions 33 snugly against the bearing housing 15 and then lift the housing from the shim 20. The clearance between the worm gear 23 and its meshing worm 24 is sufficient to permit the housing 15 to move off the shim 20.
In order to prevent any damage from occurring to the worm gear and/or line shaft, it is desirable to confine the movement of the end 12 of the conveyor roll 11 only to a vertical path. Accordingly, the jacking screws 39 are equally rotated on each side of the bracket 30 to keep the engaging portions 33 thereof snugly engaged with the bearing housing 15 while loosening the housing bolt 16 an equal amount. This procedure is continued until the bearing housing 15 is moved off the shim 20 as illustrated in FIG. 4, at which time the operator can slide the shim from beneath the housing 15.
After the shim 20 is removed, the above-described procedure is reversed; that is, the jacking screws 39 are rotated in a direction to lower the bearing housing 15 while the housing bolt 16 is tightened to draw the housing 15 towards the rail 17, whereby the housing is firmly held on the rail while the worm wheel 23 is smoothly disengaged from the rotating worm 24. The conveyor roll 11 is then removed endwise from the conveying system in a customary manner.
When a conveyor roll 11 is to be installed in an operating conveyor system, the above-described procedure is reversed.
The embodiment of the invention illustrated in FIGS. 6 through 8, and shown in a working position in FIG. 5, is adapted to be used in removing and installing conveyor rolls 11 where the bearing housing 15 is surrounded by the saddle bracket 27. Accordingly, the lifting device 31b is constructed to rest on the top surface of the bracket 27, and generally includes an anchor member 40 and a lifting pin 41 movably mounted thereon. The lifting pin 41 is provided with an engaging portion 42 that is adapted to engage a bolt 43 which is threaded into the tapped aperture from which the customary lubrication fitting (not shown) provided in the housing for lubricating the bearings 14 has been removed.
Referring particularly to FIGS. 5 and 6, the anchor member 40 is constructed to be detachably mounted on the top surface 44 of the bracket 27, and includes a plate 45 having a pair of legs 46 depending from one end thereof. Each leg 46 is provided with a lug 47 which engages the undersurface of flanges 48 projecting outwardly from the bracket 27. Each side of the plate 45 is provided with a depending tang 49 which engages the outer adjacent side of the corresponding flange 48 to prevent longitudinal movement of the plate 45 with respect to the bracket 27.
As illustrated in FIGS. 5 and 8, a portion of the plate 45 extends beyond the flanges 48 of the bracket 27 and above the bearing housing 15. This portion of the plate 45 is provided with a counterbored aperture 50 in which is disposed a thrust bearing 51 which receives the lifting pin 41 for axial movement relative thereto.
The lifting pin 41 is elongated and has a threaded shank 52 which extends through the bearing 51, and its lower end is provided with a slotted shoe 53 securely attached thereto, wherein the surface defining the slot forms the engaging portion 42. A nut 54 constituting the rotatable member, threaded on the shank 52 and abutting a washer 55 lying on the exposed end of the thrust bearing 51, moves the lifting pin relative to the anchor member 40.
When a conveying roll 11 whose supporting bearing housing 15 is surrounded by the saddle bracket 27 is to be removed from or installed in an operating conveying system, the lifting device 31b is employed. In use, the device 31b is placed on the top surface 44 of the bracket 27 with its anchor lugs 47 engaging the underside of the flanges 48, and with the slot in the shoe 53 on the lifting pin 41 surrounding the shank of the bolt 43 as shown in FIGS. 5 and 8. The nut 54 is then rotated in a direction to raise the engaging portion 42 on the shoe 53 snugly against the head of the bolt 43. The bearing housing bolt 16 (see FIG. 7) is then loosened while the shoe 53 is raised to lift the bearing housing 15 off the shim 20, at which time an operator can remove the shim 20 from beneath the housing 15. After the shim 20 is removed, the above-described procedure is reversed; that is, the nut 54 is rotated in a direction to lower the bearing housing 15 while the housing bolt 16 is tightened to draw the housing towards the rail 17 to prevent damage to the end of the roll 11 and/or its rotating mechanism. Of course, when a conveyor roll 11 is to be installed by the lifting device 31b, the above-described procedure is reversed.
It is to be understood that the forms of the invention herewith shown and described are to be taken as illustrative embodiments only of the same, and that various changes in the shape, size and arrangement of the parts may be resorted to without departing from the spirit of the invention.
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Devices for lifting and lowering the driven ends of large, heavy rotating conveyor rolls and having a rigid member provided with portions engaging bearing housings journalling the driven ends of the rolls. Rotatable members, operatively connected to the rigid member, lift and lower the engaging portions in a vertical path relative to a stationary surface mounting the bearing housings so that shims supporting the conveyor rolls in a common planar position may be removed or placed therebeneath, whereby conveyor rolls in the conveying system can be removed and installed.
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This application is a continuation-in-part of U.S. Ser. No. 08/500,878, filed May 13, 1994, now abandoned, which is a national stage of PCT/JP94/00779 filed May 13, 1994 the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to a method for examining tumor tissues. More specifically, the invention provides a method for the simultaneous diagnosis of the presence or absence of (a) hormone-dependent proliferation, and (b) a hormone synthetase in tissues and tumors. In particular, the invention provides methods for the diagnosis and treatment of hormone-dependent tumors and diseases.
BACKGROUND OF THE INVENTION
There is a class of tumors called "hormone-dependent" tumors, which generally occur in the target organs of hormones, and their growth can be promoted by or dependent on the presence of those hormones. For example, the growth of some mammary cancers is promoted by estrogen, the growth of some prostate cancers is promoted by androgen, and the growth of some thyroid cancers is promoted by thyroid stimulating hormone (TSH). Hormonal endocrine therapies are widely used for the treatment of such hormone-dependent tumors. For example, excision of estrogen-producing ovaries has been employed as an endocrine therapy for some estrogen-dependent mammary cancers. In addition, a widely used treatment for mammary cancer is the administration of an anti-estrogenic agent such as tamoxifen, which competes with estrogen for binding to the estrogen receptor, thereby exerting an antitumor effect. A biopsy of a mammary cancer is generally examined for the presence or absence of estrogen receptors in the cancerous tissue, in order to determine whether administration of an anti-estrogenic agent is indicated. In practice, a correlation between the presence of estrogen receptors and the clinical effectiveness of the anti-estrogenic agent is clinically significant. However, a positive estrogen receptor test can be misleading if the estrogen receptor is physiologically and functionally inactive. Tumors having estrogen receptors therefore do not necessarily exhibit estrogen-dependent proliferation.
Recent studies show that some tumors and other diseased tissues are capable of producing hormones which cause them to proliferate or cause the diseased tissue to be further aggravated. For example, some mammary cancers produce an enzyme called aromatase which converts androgens, such as testosterone, into estrogen. High estrogen levels in such cancer tissues have been reported. Uchimi et al., 90 J. JPN. SURG. SOC. 920-927(1989). An effective treatment for a tumor having aromatase activity and exhibiting estrogen-dependent proliferation is to administer an aromatase inhibitor. However, aromatase activity tests are rarely carried out on tumor tissue because of the difficulty in sampling the diseased tissue and in obtaining an adequate amount of tissue for determining enzymatic activity. Tumors are therefore usually only screened for the presence of estrogen receptors as an indication for aromatase inhibitor therapy. However, this test does not confirm the presence of aromatase activity, and may result in misdiagnosis because not all tumors having estrogen receptors exhibit aromatase activity, nor do all tumors having estrogen receptors necessarily exhibit estrogen-dependent proliferation. These problems are not only encountered in estrogen-related cancers, but also in other hormone-dependent cancers and diseases, and may involve one or more hormones.
SUMMARY OF THE INVENTION
The present invention provides a convenient method for the simultaneous determination of the presence or absence of a hormone synthetase and hormone-dependent proliferation in tumor cells. The method comprises culturing a tissue sample in a substrate for the hormone synthetase and comparing the growth of the tissue cells to growth in a control medium or in a medium containing the hormone synthetase substrate and an inhibitor for the hormone synthetase. The method thereby provides a classification system for tumors suspected of exhibiting hormone dependent growth and/or hormone synthetase activity. The invention further provides a method for diagnosing tumors and indicating the appropriateness of hormone synthetase inhibitor therapy.
DETAILED DESCRIPTION OF THE INVENTION
An important object of the present invention is to provide a method for the simultaneous diagnosis of hormone-dependent growth of tumor tissue and the presence of a hormone synthetase in the tissue. Another object of the invention is to provide an easy method for distinguishing a tumor type which has a hormone synthetase and proliferates hormone-dependantly (Type 1 from Table 1, below) from tumor types that do not contain hormone synthetases and/or are not hormone-dependent (Types 2, 3 and 4 from Table 1, below). Further, tumors can be classified into hormone-dependent proliferation types 1 and 2, and non-dependent proliferation types 3 and 4 as shown in Table 1.
TABLE 1______________________________________Tumor Hormone Hormone dependentType synthetase proliferation______________________________________1 + +2 - +3 + -4 - -______________________________________
The examination method of the present invention comprises the following steps:
(1) Preparing a test sample by excision or biopsy of a tissue;
(2) Culturing portions of the tissue sample for 1-14 days in each of three different media--(a) a control medium, (b) a medium containing a hormone synthetase substrate, and (c) a medium containing a hormone synthetase substrate and an inhibitor of the hormone synthetase;
(3) Measuring the proliferation of the tissue sample cells in each of the three media; and
(4) Determining the relative proliferation of the tumor cells. Tumor proliferation is determined by comparing (i) the growth of the tumor cells in the medium containing a hormone synthetase substrate (medium b) to the growth of the tumor cells in the control medium (medium a); and (ii) the growth of tumor cells in the medium containing a hormone synthetase substrate and an inhibitor for the hormone synthetase (medium c) to the growth of the tumor cells in the control medium (medium a). Thus, hormone-dependent growth of tumor tissue and the presence of a hormone synthetase can be determined simultaneously.
Tissue samples may be collected, for example, during an operation or a biopsy. The tissue sample is aseptically cut into small pieces and cultured in a medium suitable for the culture of the particular sample tissue (e.g., DMEM, Eagle, RPMI, (Gibco Co. Ltd.), soft agar or collagen matrix), according to standard methods of tissue culture (See, Nakai et al. (eds.) TISSUE CULTURE (1976)).
Any tissue which is a target for a hormone (e.g., it contains a hormone receptor and is capable of responding to the hormone by modulating its growth) may be useful for practicing the present invention. Preferred tissues for use in practicing the present invention include, but are not limited to, tumors found in mammary, endometrial, ovarian, and prostate cancers. Preferred cancer tissues for determining estrogen-dependent growth and/or the presence of aromatase activity are mammary, endometrial and ovarian cancers. A preferred cancer tissue for determining androgen-dependent growth and/or the presence of 5α-reductase activity is prostate cancer. Heretofore, only the presence of hormone receptors in these cancers has been widely investigated.
Any hormone synthetase substrate and inhibitor combination may be used in practicing the present invention, provided they are capable of stimulating cell growth and inhibiting it, respectively. A preferred hormone synthetase substrate of the present invention is the androgen testosterone, a substrate for aromatase. Accordingly, a preferred hormone synthetase inhibitor of the present invention is an aromatase inhibitor for example, 4-hydroxy-4-androsten-3,17-dione (generic name: formestane, Ciba-Geigy), 4-(5,6,7,8-tetrahydroimidazol 1,5a!pyridin-5-yl)benzonitrile monohydrochloride (generic name: fadorazole, Ciba Geigy); 14α-hydroxy-4-androsten-3,6,17-trione (code name: NKSO1, Snow Brand Milk Products, Co., Ltd.), shown in Japanese Laid-open (KOKAI) Patent Application No. 192794 (1988), 4-(5,6,7,8-tetrahydroimidazo- 1,5-α!-pyridin-5-yl)benzonitrile monohydrochloride hemihydrate (generic name: CGS16949A, product name: Afema, Novartis Co., Ltd).
Testosterone is also the substrate for the hormone synthetase 5α-reductase, by which it is converted to the androgen dihydrotestosterone. A preferred inhibitor of 5α-reductase is 17β-N,N-diethylcarbamoyl-4-aza-5α-androstan-3-one (generic name: 4MA, Merck Co., Ltd).
The above inhibitors are hereinafter referred to by their generic names.
Tissue proliferation can be determined by any art known method such as, for example, incorporation by the cells of a radiolabelled amino acid. Generally, measurement of 3 H-hymldine uptake is chosen for its simplicity and convenience. To obtain an estimate of tissue growth 3 H-thymidine is added to the culture media where appropriate, 3-4 days prior to the end of the treatment period, and is measured at the end of the culture period using liquid scintillation counting. The dpm emitted by the 3 H-thymidine is divided by the DNA content in the tissue as an internal control for differences between the tissues in each treatment medium. The growth rate is calculated from the rate of growth in the control medium relative to the rates of growth in the medium containing a hormone synthetase substrate, or in the medium containing the hormone synthetase substrate and a synthetase inhibitor. The growth rate is estimated by the following equation: Growth rate (%)=100× (the amount of incorporated 3 H-thymidine in the respective additive-containing medium/the concentration of DNA in the tissue)/(the amount of incorporated 3 H-thymidine in the additive-free medium/the concentration of DNA in the tissue)!.
The present invention further provides a new method for classifying the tissue lesions of patients with certain estrogen-dependent cancers, for example, mammary, endometrial or ovarian cancers. For example, if the growth of a cancer is estrogen-dependent and the cancer tissue contains the estrogen synthetase, aromatase, which converts testosterone to estrogen, then the tissue will grow in a medium with added testosterone. The promoted growth is suppressed by an aromatase inhibitor such as, for example, formestane, fadorazole, NKSO1 and CGS16949A. Thus, the excised tissue would be classified as a Type 1 hormone-dependent tumor (see Table 1 above). If the cancer tissue lacks estrogen-dependent growth and aromatase, then no stimulation of growth rate will be observed in the presence of testosterone and it would be classified as a Type 4 tumor.
The present invention also provides a new method for classifying the tissue lesions of patients with androgen-dependent cancers. For example, if the growth of a prostate cancer tumor is androgen-dependent and contains the dihydrotestosterone synthetase, 5α-reductase, which converts testosterone to dihydrotestosterone, then the tissue will grow in a medium with added testosterone. The promoted growth is suppressed by an 5α-reductase inhibitor, such as 4MA. Thus the excised tissue would be classified as a Type 1 hormone-dependent tumor (see Table 1 above). If the prostate cancer tissue lacks androgen-dependent growth and 5α-reductase, then no stimulation of growth rate will be observed in the presence of testosterone and it would be classified as a Type 4 tumor.
It is an important object of the invention to provide a method for the easy and simultaneous diagnosis of the presence or absence of a hormone synthetase and hormone-dependent proliferation in hormone-dependent tissues, such as tumors. It is contemplated that the present invention will provide new guidelines for the classification of tumors and the selection of medical treatment for patients, in particular cancer patients. For example, a Type 1 tumor of Table 1 is presumed to be treatable with a hormone synthetase inhibitor but Types 2, 3 or 4 would not. The present invention therefore provides a suitable medical treatment course for patients with these types of tumors.
In the method of the invention, testosterone is generally added to culture medium to a concentration of about 1-1,000 nM, preferably about 1-100 nM. The concentration of aromatase inhibitor used in the present invention depends upon its inhibitory activity and toxicity and is generally about 0.01-100 μM for NKSO1, CGS16949A or 4MA. The concentration of hormone synthetase inhibitor used in practicing the present invention must be non-toxic to the sample tissue and to the patient, if it is to be subsequently used as a treatment.
Practice of the invention will be still more fully understood from the following examples, which are presented herein below for illustration only and should not be considered as limiting the invention in any way.
EXAMPLE 1
The effects of hormone synthetase substrate and hormone synthetase inhibitor in mammary cancer tissue
Biopsies from 21 patients with mammary cancer were obtained and a tissue section of 10×10 mm was excised from the center of each mammary tumor. The necrotic portion was removed and transferred aseptically to Hanks' solution (Gibco Co., Ltd.) containing 100 U/ml each of penicillin and streptomycin (Gibco Co., Ltd.), and the tissue was then cut into pieces of 0.5-1×0.5-1 mm with a scalpel. Four to five pieces of tissue were placed on collagen matrices in a 24-well microtiter plate. The collagen matrices were prepared as follows: Spongy collagen matrix (Spongostan Co., Ltd.) was aseptically cut into pieces of 1 cm 3 , each placed into a well of a 24 well microtiter plate, and covered with phenol red-free modified Eagle MEM (Gibco Co., Ltd.) containing 10% fetal calf serum (FCS, Gibco Co., Ltd.) and 100 U/ml each of penicillin and streptomycin.
The prepared 24 well microtiter plate was placed in an atmosphere of 5% CO 2 and cultured at 37° C. for seven days. The culture medium was prepared using FCS treated with charcoal dextran and replaced every other day to keep the medium steroid-free.
Mammary cancer cells were given one of the following treatments: (1) the control group was grown in culture medium only, (2) the substrate group was grown in a medium with 10 nM testosterone added, and (3) the substrate and enzyme inhibitor group was grown in medium with 10 nM testosterone and 1 μM NKSO1 added. After seven days of culture, the culture media was changed to a media containing 0.67 μCi of 3 H-thymidine and the cells were cultured for another three days. After culturing for three days, tissue tips on the collagen sponge in each well were transferred into tubes containing 1 ml of Hanks' solution containing 0.1 mg/ml of collagenase and incubated at 37° C. for a further eight hours. The cell mass was dispersed by pipetting and then centrifuged at 3,000 rpm for 10 minutes. The precipitates formed were mixed with 1 ml of 100 mM Tris buffer, pH 7.5, containing 1% sodium dodecylsulfate and 200 μg/ml of proteinase and incubated further at 50° C. for three hours. The resultant solution was mixed with 1 ml of a mixture of phenol/chloroform/isoamyl alcohol (25:24:1) for a few minutes. The mixture was centrifuged at 3,000 rpm for 10 minutes and the upper aqueous layer was removed and mixed with 100 μl of 3M sodium acetate and 2.5 ml of cold ethyl alcohol. Precipitated DNA was gathered round a glass rod and soaked in 70%, 80% and 90% aqueous ethyl alcohol, successively, and air dried. The dried DNA was resuspended in 1 ml of 100 mM Tris buffer, pH 7.5.
The concentration of DNA in the solution was determined by the Absorbance at 260 nm and the 3 H-thymidine content of the solution was measured by liquid scintillation counting and expressed as dpm/μg DNA. The method of determining cell growth by 3 H-thymidine incorporated per weight of DNA is widely used and can be performed by conventional methods such as those described by Fukuoka et al. 43, ACTA OBST. GYNAEC. JPN, 1667, (1973). The results are shown in Table 2. A tumor was deemed "antitumor effect positive" when there was a statistical significance in the volume of the tumor in the control group compared to that in the aromatase inhibitor treated group. There are several methods available for measuring the statistical significance of the effects and a T-test with a significance level of 5% or less was chosen.
TABLE 2______________________________________Growth Rate (%) Medium with Medium withPatient Testosterone Inhibitor (NKSO1) Diagnosis______________________________________A 114.4 104.1B 96.9 95.0C 167.1 114.8D 100.7 97.7E 102.3 98.1F 114.6 98.6 Type 1G 104.0 107.4H 117.5 126.8I 120.5 99.8 Type 1J 101.2 117.7K 88.4 97.9L 120.9 97.2 Type 1M 129.7 77.4 Type 1N 100.3 95.2O 97.4 98.4P 156.4 101.3 Type 1Q 92.9 98.8R 108.8 95.2S 160.7 103.3 Type 1T 98.9 92.4U 92.6 93.6______________________________________
Mammary cancer tissues exhibiting estrogen-dependent proliferation and having aromatase activity were found in six out of 21 patients by the examination method of the present invention. The proliferation of these mammary cancer cells was hormone-dependent and was presumed to be regulated by hormones synthesized in their tumor tissues.
EXAMPLE 2
The effects of hormone synthetase substrate and hormone synthetase inhibitor on cell lines in vitro and tumor tissue derived from those cell lines in vivo
The effectiveness of using an aromatase inhibitor to inhibit cell proliferation according to the present invention was examined using four tumor cell lines of human origin (Table 3). These cell lines were examined for the expression of estrogen receptor according to standard methods well known in the art and the results are summarized in Table 3.
TABLE 3______________________________________ Presence ofTumor Cell line Tissue Source Estrogen Receptor______________________________________MCF-7 Human mammary cancer YesBG-1 Human ovarian cancer YesR-27 Human mammary cancer YesISHIKAWA Human endometrial cancer Yes______________________________________
Each of the above cell lines was inoculated subcutaneously into the axillary fossa of 7-week-old female nude mice at 1×10 5 cells/0.1 ml/mouse to give solid tumors. The tumors were grown to approximately 1 cm diameter and resected and cultured according to the procedure described in Example 1. The cultured tumor cells were given one of the following treatments: (1) the control group was grown in medium only, (2) the substrate group was grown in medium with 10 nM testosterone added, and (3) the substrate and enzyme inhibitor group was grown in medium with 10 nM testosterone and 1 μM NKSO1 added. The cells were cultured and cell growth measured as described in Example 1. The results are shown in Table 4. A tumor was deemed "Type 1" according to the statistical method described in Example 1.
TABLE 4______________________________________ Growth rate (%)Tumor Cell line Testosterone Inhibitor (NKSO1) Diagnosis______________________________________MCF-7 635.3 102.0 Type 1BG-1 288.7 117.6 Type 1R-27 106.7 102.9 Type 2ISHIKAWA 307.0 279.2 Type 2______________________________________
These tumor-derived cell lines were re-inoculated subcutaneously into the axillary fossa of 7-week-old female nude mice at 1×10 5 cells/0.1 ml/mouse to form solid tumors. The mice were divided into two groups each containing 10 mice and treated as follows until the tumor mass became approximately 3 mm in diameter: (1) a control group, to which an aromatase inhibitor was not administered, and (b) a test group to which an aromatase inhibitor was administered every day until the test was over.
The aromatase inhibitors administered included NKSO1, formestane, and fadorazole. NKSO1 was administered orally at a dosage of 100 mg/kg/day and formestane was administered subcutaneously at a dosage of 50 mg/kg/day. Fadorazole was administered orally at a dosage of 25 mg/kg/day for MCF-7 tumor injected mice, 60 mg/kg/day for BG-1 tumor injected mice, and 3 mg/kg/day for R-27 tumor injected mice. The administration period of the inhibitors depended upon the proliferation rates of the respective tumors in the nude mice, and was 28 days for BG-1, R-27 and ISHIKAWA, and 42 days for MCF-7. The longer and shorter axes of the tumors were determined on the next day after the final administration using a vernier caliper. The volume of the tumors was calculated using the following equation: Estimated volume of tumor=(longer axis)×(shorter axis) 2 ×0.5.
The antitumor effects of the aromatase inhibitors on mice injected with the tumor cells derived from the four tumor cell lines are shown in Table 5.
TABLE 5______________________________________Tumor Control Aromatase InhibitorCell line Group NKSO1 Formestane Fadorazole______________________________________MCF-7 635 ± 89.sup.1) 339 ± 46 289 ± 68 255 ± 41 (p < 0.05).sup.2) (p < .05) (p < 0.05) Effective Effective EffectiveBG-1 1,022 ± 309 394 ± 78 ND 401 ± 86 (p < 0.05) (p < 0.05) Effective EffectiveR-27 1,298 ± 266 1,145 ± 245 ND 1,321 ± 564 Not Effective Not effectiveISHIKAWA 1,357 ± 576 1,435 ± 746 ND ND Not Effective______________________________________ 1): Estimated volume of tumor Average ± SD (mm.sup.3) 2): Ttest result with those of the control group. ND: No experiment was performed.
The results obtained in the treatment of the tumor derived-cells with the aromatase inhibitor using the method of the present invention correlated with the practical therapeutic effect of aromatase inhibitor treatment as shown in Table 6 below. As shown by the above mentioned examples, the examination method of the present invention clearly distinguished the indications of aromatase inhibitor therapy for mice with an estrogen dependent tumor.
TABLE 6______________________________________IndicationforaromataseTumor inihibitor Tumor Aromatase InhibitorCell Line therapy Type NKSO1 Formestane Fadorazole______________________________________MCF-7 Indicated 1 Effective Effective EffectiveBG-1 Indicated 1 Effective ND EffectiveR-27 Not 2 Not ND Not inicated Effective EffectiveISHI- Not 2 Not ND NDKAWA indicated Effective______________________________________ ND: No experiment was performed
EXAMPLE 3
The effects of a hormone synthetase substrate and hormone synthetase inhibitor on endometrial cancer tissue
Biopsies from 15 patients with endometrial cancer were obtained and cultured according to Example 1. The cultured endometrial cancer cells were given one of the following treatments: (1) the control group was grown in medium only, (2) the substrate group was grown in a medium with 10 nM testosterone added, or (3) the substrate and enzyme inhibitor group was grown in a medium with 10 nM testosterone, 1 μM NKSO1 and 10 nM CGS16949A added. The cells were cultured and cell growth measured as described in Example 1. The results are shown in Table 7. A tumor was deemed "Type 1" according to the statistical method described in Example 1.
TABLE 7______________________________________Growth Rate (%)Patient Testosterone Inhibitor.sup.a,b Diagnosis______________________________________A 102.3% 102.8%.sup.aB 143.6% 105.7%.sup.a TYPE 1C 102.1% 98.9%.sup.aD 110.8% 105.8%.sup.aE 106.0% 100.4%.sup.aF 156.5% 108.6%.sup.a TYPE 1G 104.4% 105.3%.sup.aH 109.2% 100.9%.sup.aI 107.8% 104.4%.sup.aJ 105.5% 99.1%.sup.a 98.2%.sup.bK 107.9% 109.6%.sup.a 108.9%.sup.bL 145.1% 108.1%.sup.a 109.7%.sup.b TYPE 1M 187.7% 110.5%.sup.a 109.9%.sup.b TYPE 1N 101.1% 106.4%.sup.a 105.5%.sup.bO 103.6% 104.0%.sup.a 103.6%.sup.b______________________________________ .sup.a NKSO1 .sup.b CG516949A
As shown in Table 7, four of the fifteen cancers were determined to be Type 1 tumors.
EXAMPLE 5
The effects of hormone synthetase substrate and hormone synthetase inhibitor on ovarian cancer tissue
Biopsies from 9 patients with ovarian cancer were obtained and cultured according to Example 1. The cultured ovarian cancer cells were given one of the following treatments: (1) the control group was grown in medium only, (2) the substrate group was grown in a medium with 10 nM testosterone added, or (3) the substrate and enzyme inhibitor group was grown in a medium with 10 nM testosterone, 1 μM NKSO1 and 10 nM CGS16949A added. The cells were cultured and cell growth measured as described in Example 1. The results are shown in Table 8. A tumor was deemed "Type 1" according to the statistical method described in Example 1.
TABLE 8______________________________________Growth Rate (%)Patient Testosterone Inhibitor.sup.a,b Diagnosis______________________________________A 141.2% 105.2%.sup.a TYPE 1B 133.0% 102.1%.sup.a TYPE 1C 101.8% 94.6%.sup.aD 103.4% 100.7%.sup.aE 142.9% 106.5%.sup.a TYPE 1F 102.1% 103.3%.sup.a 99.1%.sup.aG 107.1% 101.2%.sup.a 99.5%.sup.aH 103.7% 97.1%.sup.a 102.7%.sup.aI 144.2% 105.5%.sup.a 110.3%.sup.a TYPE 1______________________________________ .sup.a NKSO1 .sup.b CGS16949A
As shown in Table 8, four of the nine cancers were determined to be Type 1 tumors.
EXAMPLE 6
The effects of hormone synthetase substrate and hormone synthetase inhibitor on prostate cancer tissue
Biopsies from 8 patients with prostate cancer were obtained and cultured according to Example 1. The cultured prostate cancer cells were given one of the following treatments: (1) the control group was grown in medium only, (2) the substrate group was grown in medium with 10 nM testosterone added, and (3) the substrate and enzyme inhibitor group was grown in a medium with 10 nM testosterone and 1 μM 4MA added. The cells were cultured and cell growth measured as described in Example 1. The results are shown in Table 9. A tumor was deemed "Type 1" according to the statistical method described in Example 1.
TABLE 9______________________________________Growth rate (%)Patient Testosterone Inhibitor (4MA) Diagnosis______________________________________A 101.1% 97.8%B 173.1% 107.0% TYPE 1C 167.2% 105.6% TYPE 1D 111.6% 104.4%E 191.2% 112.5% TYPE 1F 161.0% 102.8% TYPE 1G 104.1% 102.2%H 172.5% 107.9% TYPE 1______________________________________
As shown in Table 9, five of the nine cancers were determined to be Type 1 tumors.
Equivalents
Those skilled in the art will be able to ascertain many equivalents to the specific embodiments described herein. Such equivalents are intended to be encompassed by the scope of the following claims.
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The invention relates to an examination method of hormone-dependent tissue, more particularly to a method for examining hormone-dependent tumors by culturing a tumor tissue in (a) a control culture medium, (b) a culture medium containing a hormone synthetase substrate, and (c) a culture medium containing a hormone synthetase substrate and a hormone synthetase inhibitor, and determining the relative growth ratios of tumor cells of (b) to (a), and (c) to (a) for diagnosing a tumor as being hormone dependent.
This invention provides a method for the simultaneous and easy determination of hormone dependent tumors and the presence of hormone synthetic enzymes. Further, this invention provides a new classification system for tumors and means for indicating medical treatment for a cancer patient.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part application of U.S. patent application Ser. No. 09/685,818, filed Oct. 10, 2000, which was itself a continuation-in-part application of U.S. patent application Ser. No. 09/411,295 filed Oct. 4, 1999.
BACKGROUND OF THE INVENTION
[0002] This invention relates to heat exchangers, and in particular, to plate and fin type heat exchangers such as the type used with internal combustion engines for cooling engine coolant.
[0003] In the past, engine coolant heat exchangers, such as radiators, have been made by providing a plurality of parallel, spaced-apart flat tubes with cooling fins located therebetween to form a core. Opposed ends of the tubes pass through openings formed in manifolds or headers located on each side of the core at the respective ends of the tubes. A difficulty with this type of construction is that the tube to header joints are difficult to fabricate and prone to leakage.
[0004] A method of overcoming these difficulties is shown in U.S. Pat. No. 3,265,126 issued to D. M. Donaldson. In this patent, headers are provided with a continuous longitudinal opening, and the tubes are formed with specially shaped ends to fit into this continuous opening, thus simplifying the assembly and reducing the leakage problem. A difficulty with the Donaldson structure, however, is that the shape of the various components is quite complex resulting in high tooling costs.
[0005] The present invention is a heat exchanger of universal application where relatively simple and inexpensive tooling is required to make heat exchangers of different types and even with differing sizes and configurations.
SUMMARY OF THE INVENTION
[0006] According to one aspect of the invention, there is provided a heat exchanger comprising a plurality of stacked plate pairs formed of mating plates having central planar portions and raised peripheral edge portions. The edge portions are joined together in mating plates to define a flow channel between the plates. The plates have offset end flanges, the respective flanges at each end of each plate pair diverging. The flanges have lateral edge portions extending from root areas located at the joined peripheral edge portions. The end flanges also have transverse distal edge portions joined together in back-to-back stacked plate pairs to space the plate pairs apart and form transverse flow passages between the plate pairs. Opposed U-shaped channels enclose the respective end flanges of the plate pairs. The channels have rear walls spaced from the plate end flanges and side walls joined to the flange lateral edge portions covering the root areas. The U-shaped channels have open ends. End plates close the U-shaped channel open ends to form manifolds. Also, the manifolds define inlet and outlet openings therein for the flow of fluid through the plate pairs.
[0007] According to another aspect of the invention, there is provided a method of making a heat exchanger comprising the steps of providing an elongate strip of plate material having a planar central portion and raised peripheral edge portions. The plate material is cut into predetermined lengths. The plate lengths are formed with offset end flanges extending in a direction away from the peripheral edge portions. The plate lengths are arranged into plate pairs with the offset end flanges diverging and the plate peripheral edge portions in contact. The plate pairs are stacked so that the end flanges engage to space the plate pairs apart. U-shaped channels are provided to enclose the plate offset end flanges, the channels having open ends. The channel open ends are closed to form manifolds, and inlet and outlet openings are formed in the manifolds. The plates and manifolds are joined together to form a sealed heat exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0009] [0009]FIG. 1 is a top, left perspective view of a preferred embodiment of a heat exchanger made in accordance with the present invention;
[0010] [0010]FIG. 2 is a bottom left perspective view of the lower corner of the heat exchanger shown in FIG. 1 as viewed in the direction of arrow 2 ;
[0011] [0011]FIG. 3 is an enlarged perspective view taken in the direction of arrow 3 of FIG. 1 showing a portion of the heat exchanger of FIG. 1 being assembled;
[0012] [0012]FIG. 4 is a plan view taken along lines 4 - 4 of FIG. 3;
[0013] [0013]FIG. 5 is an enlarged scrap view of the area of FIG. 4 indicated by circle 5 ;
[0014] [0014]FIG. 6 is a plan view similar to FIG. 4 showing the addition of a baffle in one of the manifolds;
[0015] [0015]FIG. 7 is a plan view similar to FIGS. 4 and 6 but showing another preferred embodiment of the present invention;
[0016] [0016]FIG. 8 is a vertical sectional view taken along lines 8 - 8 of FIG. 6 showing various types of baffles that could be used in the manifolds of the present invention;
[0017] [0017]FIG. 9 is a plan view similar to FIG. 4 but showing another preferred embodiment of the invention;
[0018] [0018]FIG. 10 is a plan view similar to FIGS. 4 and 9, but showing a modification to the embodiment of FIG. 9;
[0019] [0019]FIG. 11 is a plan view similar to FIG. 4, but showing a modification to the flange extensions;
[0020] [0020]FIG. 12 is a vertical sectional view taken along lines 12 - 12 of FIG. 11;
[0021] [0021]FIG. 13 is a vertical sectional view similar to FIG. 12 but showing a modified form of flange extension;
[0022] [0022]FIG. 14 is a bottom left perspective view of similar to FIG. 2 but showing a modification for locking the plate pairs together;
[0023] [0023]FIG. 15 is a top, left perspective view of another preferred embodiment of a heat exchanger made in accordance with the present invention;
[0024] [0024]FIG. 16 is an enlarged vertical sectional view taken along lines 16 - 16 of FIG. 15 showing the lower left corner of the heat exchanger of FIG. 15;
[0025] [0025]FIG. 17 is a bottom left perspective view similar to FIG. 2 but showing another preferred embodiment of an end bracket;
[0026] [0026]FIG. 18 is an enlarged view similar to FIG. 8 showing various types of baffles and turbulizing enhancements that could be used in the heat exchangers of the present invention;
[0027] [0027]FIG. 19 is a view similar to FIG. 9 showing a plate formed with dimples;
[0028] [0028]FIG. 20 is a view similar to FIG. 9 showing a plate formed with ribs;
[0029] [0029]FIG. 21 is a perspective view of the turbulizer of FIG. 18; and
[0030] [0030]FIG. 22 is a perspective view similar to FIG. 3 illustrating a strengthening element.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] Referring firstly to FIG. 1, a preferred embodiment of a heat exchanger according to the present invention is generally indicated by reference numeral 10 . Heat exchanger 10 is in the form of a radiator for cooling the coolant of an internal combustion engine, such as is typically found in an automotive vehicle. Heat exchanger 10 includes a filler cap 12 mounted in a suitable fitting 14 having an overflow or pressure relief outlet 16 . Heat exchanger 10 has a core 18 formed of a plurality of spaced-apart plate pairs 20 with cooling fins 22 located therebetween. Cooling fins 22 are the usual type of corrugated cooling fins having transverse undulations or louvres 24 formed therein to increase heat transfer (see FIGS. 3 and 8). Any type of cooling fin could be used in the present invention, or even no cooling fin at all, if desired.
[0032] Heat exchanger 10 has a pair of manifolds 26 , 28 located at the respective ends of plate pairs 20 . Inlet and outlet nipples or fittings 30 , 32 are mounted in one of the manifolds 26 , 28 for the flow of coolant into and out of heat exchanger 10 , as will be described further below. An optional temperature sensor 34 can also be mounted in one of the manifolds 26 , 28 to sense the temperature of the coolant inside heat exchanger 10 .
[0033] A top end plate 36 closes the upper ends of manifolds 26 , 28 and provides a location for mounting the filler cap fitting 14 and also a bracket 38 for mounting heat exchanger 10 in a desired located. A bottom end plate 40 is also provided to close the lower ends of manifolds 26 , 28 and provide a location for the attachment of another mounting bracket 42 for mounting heat exchanger 10 in a desired location. If desired, filler cap 12 could be mounted in or attached to the walls of either manifold 26 or 28 instead of end plate 36 .
[0034] Referring next to FIGS. 3 and 8, plate pairs 20 are formed of top and bottom mating plates 44 , 46 . Each plate 44 , 46 has a central planar portion 48 and raised peripheral edge portions 50 , 52 , so that when the plates 44 , 46 are put together face-to-face, the peripheral edge portions 50 , 52 are joined together and the planar central portions 48 are spaced apart to define a flow channel 54 (see FIG. 8) between the plates.
[0035] As seen best in FIGS. 3 and 8, plates 44 , 46 have offset end flanges 56 , 58 . The respective end flanges 56 , 58 at each end of each plate pair 20 diverge from a root area 60 where the raised peripheral edge portions 50 , 52 are still joined together, to transverse distal edge portions or flange extensions 62 . The offset end flanges 58 also have lateral edge portions 64 that extend from root areas 60 to transverse distal edge portions 62 . It will be noted that transverse distal edge portions or flange extensions 62 are joined together in back-to-back stacked plate pairs 20 . This spaces the plate pairs 20 apart to provide transverse flow passages 66 between the plate pairs where cooling fins 22 are located.
[0036] Manifolds 26 , 28 are formed of opposed, U-shaped channels having rear walls spaced from the plate offset end flanges 56 , 58 , and side walls 70 , 72 joined to the flange lateral edge portions 64 . The channel side walls 70 , 72 actually cover the root areas 60 where the peripheral flanges 50 , 52 are still joined together, and since the lateral edge portions 64 of offset end flanges 56 , 58 are joined to the inside walls of channel side walls 70 , 72 , a fluid tight seal is provided, so that fluid inside manifolds 26 , 28 can only flow through the flow channels 54 inside plate pairs 20 .
[0037] The U-shaped channels or manifolds 26 , 28 are formed from folded or formed aluminum sheet or an aluminum extrusion cut to a desired length and thus have open ends 74 . Top end plate 36 closes the open ends 74 at the top of manifolds 26 , 28 and bottom end plate 40 closes the bottom open ends 74 of manifolds 26 , 28 . As seen best in FIGS. 2 and 8, bottom end plate 40 also has offset end flanges 76 that fit snugly inside the U-shaped channels or manifolds 26 and 28 and engage the flange extension 62 formed on the adjacent bottom plate 46 . Bottom end plate 40 is actually an inverted U-shaped member having side skirts 78 with distal extensions 80 that wrap around manifolds 26 , 28 to help hold heat exchanger 10 together during assembly. If desired, top end plate 36 could be the same configuration as bottom end plate 40 .
[0038] It will be appreciated that U-shaped manifolds 26 , 28 could have other cross-sectional configurations, such as trapezoidal, or hemispheroidal. For the purposes of this disclosure, the term “U-shaped” is intended to include any cross-sectional configuration that is capable of enclosing offset end flanges 56 , 58 .
[0039] Referring next to FIGS. 3 to 5 , it will be seen that raised peripheral edge portions 50 , 52 are formed with fingers 82 spaced from the flange lateral edge portions 64 to define slots 84 to accommodate the U-shaped channel side walls 70 , 72 . As seen best in FIG. 5, slots 84 are slightly tapered inwardly to urge the U-shaped channel side walls 70 , 72 into tight engagement with lateral edge portions 64 . This provides a snug fit, so that manifolds 26 , 28 actually clip on and are retained in position during the assembly of heat exchanger 10 . If desired, fingers 82 could be twisted 90 degrees during assembly to help lock the manifold walls 70 , 72 against lateral edge portions 64 . Slots 84 are slightly deeper or longer than the length of side walls 70 , 72 that extend into the slots for purpose which will be described further below.
[0040] [0040]FIG. 6 shows the use of a baffle 86 attached to one of the flange extensions 62 and extending between the U-shaped channel rear wall 68 and side walls 70 , 72 to divide manifold 26 into separate compartments above and below baffle 86 . Baffle 86 would be used in a location, for example, such as is shown by chain dotted lines 88 in FIG. 1 to divide manifold 26 into a lower compartment 90 communicating with inlet fitting or opening 30 , and an upper compartment 92 communicating with outlet fitting or opening 32 . In this way, fluid entering inlet 30 would pass through the plate pairs 20 located below baffle 86 , enter manifold 28 and flow upwardly to pass back through the plate pairs located above baffle 86 to exit through outlet 32 . Baffle 86 could be located at any plate pair between inlet 30 and outlet 32 to balance the cooling inside heat exchanger 10 .
[0041] [0041]FIG. 8 shows various types of baffles that could be used in heat exchanger 10 . This is for illustration only, because normally there would only be one baffle used in heat exchanger 10 . However, if it were desired to divide heat exchanger 10 into multiple discrete heat exchangers or zones, each having its own inlet and outlet, then any number of baffles could be used to divide up heat exchanger 10 into separate heat exchangers. Also, the baffles could be used selectively in both the manifolds 26 , 28 to cause the coolant to flow in a serpentine path through the heat exchanger, if desired.
[0042] In FIG. 8, baffles 86 , 93 , 94 and 95 are shown having bifurcated inner ends to engage the mating flange extensions 62 . These bifurcated ends 96 also help hold flange extensions 62 together during assembly of heat exchanger 10 . Baffles 86 , 94 and 97 also have resilient wall portions 98 to act as springs to ensure a good seal against the U-shaped channel rear wall 68 , and to accommodate any movement of the heat exchanger components while they are being joined together, such as by brazing.
[0043] It is also possible to fasten baffles to the rear wall 68 of the U-shaped channel 26 by mechanical fasteners, as illustrated in FIG. 18, wherein an illustrative baffle 200 is shown as affixed to the manifold 26 by a rivet 202 .
[0044] [0044]FIG. 7 shows another preferred embodiment wherein the plate raised peripheral edge portions 50 , 52 are formed with transverse notches 100 instead of slots 84 as in the embodiment of FIG. 6. Notches 100 are located inwardly of but adjacent to the lateral edge portions 64 and root areas 60 where offset end flange 58 start to diverge. Channel side walls 70 , 72 are formed with inwardly disposed peripheral flanges 102 that are located in notches 100 . Notches 100 are deeper than flanges 102 , and side walls 70 , 72 are somewhat resilient, so peripheral flanges 102 snap into notches 100 allowing the U-shaped channels to clip on to the core assembly and lock the assembly together.
[0045] Plates 44 , 46 in FIG. 7 are also formed with longitudinal, inwardly disposed matching ribs 104 which strengthen the plate pairs and keep the planar central portions 48 from sagging during the brazing process to complete heat exchanger 10 . If desired, longitudinal ribs 104 could also be employed in the embodiment shown in FIGS. 2 to 6 . Multiple ribs 104 could be provided as well. Also, instead of ribs 104 , central portions 48 could be formed with dimples 204 that extend inwardly in mating engagement in the plate pairs as illustrated in FIGS. 18 and 19, thereby to define flow restrictions in the flow channels 54 , to increase turbulence. Another possibility is to provide a flow enhancing turbulizer 208 in the flow channels 54 , between the plates of the plate pairs 20 , as illustrated in FIGS. 18 and 21. The turbulizer 208 illustrated in FIGS. 18 and 21 is of the expanded metal variety, although other turbulizers may be utilized. Instead of turbulizers it is also possible to form the plates with raised ribs or ridges 206 to project into the flow channels, as illustrated in FIGS. 18 and 20, thereby to provide for increased turbulence. The ribs 206 illustrated in FIG. 20 are arranged at an angle, preferably in a herringbone pattern, with one of the mating plates 44 , 46 turned end for end, so that the ribs 206 engage in a crossing fashion, although other arrangements are possible. The ribs 206 can also be of shortened height, so that they do not engage in mating plates, if desired.
[0046] Referring next to FIG. 9, another preferred embodiment of the invention is shown where peripheral edge portions 50 , 52 are formed with necked-in portions 106 instead of slots 84 as in the embodiment of FIG. 6. Necked-in portions 106 extend inwardly beyond lateral edge portions 64 and root areas 60 where offset end flanges 58 start to diverge, so that channel side walls 70 , 72 provide a sealed enclosure communicating with the flow passages between the plates of the plate pairs 20 .
[0047] [0047]FIG. 10 is similar to FIG. 9, but shows side walls 70 , 72 having outwardly disposed peripheral flanges 108 . Flanges 108 provide a surface upon which a fixture can press to urge manifolds inwardly to hold the components of heat exchanger 10 together during the assembly and brazing process.
[0048] In the embodiments shown in FIGS. 9 and 10, manifolds 26 , 28 are still considered to “clip on” for the purposes of the present invention, since the manifold side walls 70 , 72 would be somewhat resilient and would frictionally engage lateral edge portions 64 to hold the manifolds in place, at least during the initial assembly of the components of the heat exchangers of the invention.
[0049] [0049]FIGS. 11 and 12 show a further modification which is applicable to any of the embodiments described above. In the FIGS. 11 and 12 embodiment, the transverse distal edge portions or flange extensions 62 are formed with cutouts or notches 110 . Flange extensions 62 can be made with different widths to adjust the flow through manifolds 26 , 28 and notches 110 can be used to further refine or fine tune the flow patterns inside the manifolds. As seen best in FIG. 12, flange extensions 62 are curved to ensure a good seal therebetween, in case the notches 110 do not line up perfectly in the assembly of heat exchanger 10 .
[0050] [0050]FIG. 13 is a view similar to FIG. 12, but it shows a further modification of flange extensions 62 in that they extend inwardly instead of outwardly as in the previous embodiments. Again, this configuration could be used in any of the embodiments described above. The inwardly directed flanges 62 give the maximum unobstructed flow through manifolds 26 , 28 .
[0051] [0051]FIG. 14 is a view similar to FIG. 2, but it shows a modification to end plate 40 where distal extensions 80 have been eliminated. Instead of distal extensions 80 to help hold the heat exchanger components together during the assembly process, manifold rear walls 68 are formed with tabs 112 that are bent over to engage offset end flanges 76 of end plate 40 . Tabs 112 help hold the stack of plate pairs 20 together while the heat exchanger is being set up for brazing. If desired, however, both tabs 112 and the distal extensions 80 of the FIG. 2 embodiment could be used together in the same heat exchanger.
[0052] Referring next to FIGS. 15 and 16, another preferred embodiment of a heat exchanger 112 is shown, which has top and bottom manifolds 28 and 26 instead of side mounted manifolds as in FIG. 1. In heat exchanger 112 , the U-shaped channels or manifolds 26 , 28 are formed with parallel, U-shaped, inwardly disposed ribs 114 , 116 adjacent to their ends to accommodate and act as locating guides for the offset end flanges 76 of end plates 40 . It will be noted that rib 116 is shorter than rib 114 to accommodate the adjacent plate flange extension 62 . The ribs engage and locate the end plates to ensure that good brazing joints are achieved between end plate offset end flanges 76 and manifolds 26 , 28 .
[0053] [0053]FIGS. 15 and 16 also show some additional optional guide and braze enhancing means for the plate flange extensions 62 . One option is to use parallel, inwardly disposed, closely spaced-apart, short ribs 118 to sandwich therebetween the peripheral edges of flange extensions 62 . Another option is to use inwardly disposed bosses 120 that appear as dimples from the outside of manifolds 26 , 28 . The bosses could be U-shaped as indicated by U-shaped dimples 122 in FIG. 15 (not shown in FIG. 16). These U-shaped bosses or dimples 122 would be particularly useful where a baffle is employed in manifolds 26 , 28 .
[0054] [0054]FIG. 16 also shows a couple of other modifications to the preferred embodiments, such as an extended distal flange extension 124 on one of the plates of a plate pair 20 . Extended flange extension 124 extends fully between the U-shaped channel or manifold rear and side walls to form a baffle inside manifolds 26 , 28 . A further modification is illustrated in FIG. 22, wherein the extended distal flange extension 124 on one of the plates of a plate pair 20 is provided with an aperture 216 so as to permit fluid flow. In this latter modification, the extended distal flange extension 124 is a strengthening element for the manifold 26 . As another embodiment, illustrated in FIG. 18, the extended distal flange extension 124 can have a resilient end portion 212 to act as a spring to ensure a good seal against the U-shaped channel rear wall 68 .
[0055] [0055]FIG. 16 also shows that lateral or side flanges 126 could be provided on the plate offset end flanges 56 , 58 to help ensure good brazing joints between end flanges 56 , 58 and the adjacent walls of the manifolds 26 , 28 . Also shown are transverse, distal, offset flanges 128 that could be added to flange extensions 62 to keep flange extensions 62 straight during the brazing process and help provide good bonds therebetween.
[0056] Referring next to FIG. 17, a modification to the end plates is shown where end plate 130 side skirts 78 extend integrally around offset end flange 76 to form a pan type end portion that engages the bottom walls of the manifolds 26 , 28 .
[0057] In a typical application, the components of heat exchanger 10 are made of brazing clad aluminum (except for the peripheral components such as fittings 30 , 32 , filler cap and fitting 12 , 14 and mounting brackets 38 , 42 ). The brazing clad aluminum for core plates 44 , 46 typically have a metal thickness between 0.3 and 1 mm (0.012 and 0.040 inches). End plates 36 and 40 have a thickness between 0.6 and 3 mm (0.024 and 0.120 inches), and baffles 86 , 93 , 94 , 95 and 97 have a thickness between 0.25 and 3 mm (0.010 and 0.120 inches). However, it will be appreciated that materials other than aluminum can be used for the heat exchangers of the present invention, even plastic for some of the components, if desired.
[0058] The preferred method of making heat exchanger 10 is to roll form an elongate strip of plate material having planar central portion 48 and raised peripheral edge portions 50 , 52 . Preferably, the plates are formed of brazing clad aluminum. The plate material is then cut into predetermined lengths to determine the desired width of heat exchanger 10 . The ends of the plates are then formed, such as by stamping, to create offset end flanges 58 and either slots 84 , notches 100 or necked-in portions 106 . The plates are then arranged into plate pairs with the offset end flanges 58 diverging or extending in a direction away from peripheral edge portions 50 , 52 . The peripheral edge portions 50 , 52 are thus engaged or in contact. The plate pairs are then stacked together in any desired number. Cooling fins 22 are located between the plate pairs during the stacking process. U-shaped channels 26 , 28 are then cut to length to match the height of the stacked plate pairs. Any desired baffles are attached to the plate pairs at selected locations, and the U-shaped channels are then pressed, slid or clipped onto the ends of the stacked plate pairs enclosing the offset end flanges 58 . Top and bottom end plates 36 , 40 are then located to close the open ends of the U-shaped channels. Any other fittings or attachments, such as inlet and outlet fittings 30 , 32 , filler cap fitting 14 or brackets 38 , 42 can be located on the assembly, and the entire assembly is then placed into a brazing furnace to braze the components together and complete the heat exchanger.
[0059] Having described preferred embodiments of the invention, it will be appreciated that various modifications may be made to the structures described above. Other types of cooling fins could be used, or no fins at all. The heat exchangers could be made of other materials than brazing clad aluminum such as plastic. Also, the manifolds could have other shapes, if desired.
[0060] As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.
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A plate and fin type heat exchanger is disclosed which can be made in any convenient size with minimum tooling required. The heat exchanger is made from a plurality of stacked plate pairs having raised peripheral edge portions to define flow channels inside the plate pairs. The plates of the plate pairs are formed with offset, diverging end flanges that space the plate pairs apart. A U-shaped channel envelops the plate end flanges to form part of a manifold at each end of the plate pairs. End caps or plates close the open ends of the U-shaped channels to complete the manifolds, and inlet and outlet openings are formed in the manifolds as desired to complete the heat exchanger.
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TECHNICAL FIELD
[0001] The present invention relates to the field of organic synthesis. More particularly it provides a process for making an indenol ester or ether from an α-substituted cinnamic aldehyde derivative such as an acetal or an acylal. This reaction is promoted by the use of strong mineral acids, sulphonic acids, acidic zeolites or Lewis acids.
BACKGROUND
[0002] The organic compounds of formula (I), as defined below, can be useful as perfuming ingredients or as starting material for the synthesis of compounds having a more complex skeleton. The methods of preparation of such compounds as reported in the prior art are in general quite long and/or expensive. Thus, there is a need for improved processes for preparing such compounds.
[0003] It would be highly desirable to access such compounds by means of a simple and efficient isomerization process wherein the starting material is an easily accessible material. To the best of our knowledge, there is no report in the prior art of an isomerization process giving a direct access to compounds of formula (I) from the compound of formula (II).
SUMMARY OF THE INVENTION
[0004] In order to solve the problems aforementioned, a first embodiment of the present invention provides a process for making a compound of formula
wherein m is 0, 1 or 2;
R 1 represents a formyl group, a —COCOOH group or a group of formula —(CO) n —R-T, in which n is 0 or 1, R is a C 6 H 4 group, C 1-5 alkanediyl or alkenediyl group and T is OH, COOH or a hydrogen atom; R 2 represents a C 1-6 alkyl or alkenyl group; at least one R 3 represents a hydrogen atom and the other R 3 represent each a hydrogen atom or a C 1-5 alkyl, alkenyl or alkoxy group; and R 4 represents a hydrogen atom, a phenyl group or a R 2 group;
comprising the cyclization, at a temperature above 10° C. of the corresponding compound of formula
wherein each R 5 , taken separately, represents a formyl group or a —(CO) n —R—H group, or the R 5 , taken together, represent a —(CO) n —R—(CO) n — group or a —COCO— group; the wavy line indicates that the configuration of the carbon-carbon double bond is E or Z or a mixture thereof; and m, n, R, R 2 , R 3 and R 4 have the meaning as indicated above;
in the presence of a catalyst selected from the group consisting of strong mineral protic acids, sulphonic acids, acidic zeolites and Lewis acids.
[0012] For the invention purpose, it is important that R 2 is not a hydrogen atom, indeed if R 2 is H then the reaction does not take place.
[0013] According to an embodiment of the present invention, m is preferably 0 or 1, or even more preferably 0.
[0014] Furthermore, according to one of the above-described embodiments, R 1 may also represent a group of formula —(CO) n —R-T, in which n is 0 or 1, R is a C 6 H 4 group or a C 1 -C (5-n) alkanediyl or alkenediyl group and T is OH, COOH or a hydrogen atom. Alternatively R 1 may also represent a group of formula —(CO) n —R-T, in which n is 0 or 1, R is a C 1 -C (3-n) alkanediyl group and T is OH, COOH or a hydrogen atom.
[0015] According to these embodiments R 2 may represent a C 1-6 alkyl group.
[0016] Moreover, in such embodiments, at least two R 3 may represent a hydrogen atom and the other R 3 may represent each a hydrogen atom or a C 1-5 alkyl or alkoxy group.
[0017] Furthermore, R 4 may represent a hydrogen atom or a C 1-6 alkyl group, and preferably is a hydrogen atom.
[0018] The invention also relates to certain compounds that are made by these processes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] According to a particular embodiment of the invention the compounds of formula (1) are of formula
and are obtained by cyclization of the corresponding compounds of formula
wherein R 1 , R 2 , R 3 and R 5 have the same meaning as indicated above.
[0020] The compounds of formula (I′) wherein one R 3 is a hydrogen atom and the other R 3 is a C 1-5 alkyl group are new compounds and can be used as starting compounds for the synthesis of indenols. Amongst these compounds can be cited the 2-methyl, the 2,5-dimethyl or the 2,6-dimethyl derivatives of formula (I′).
[0021] The catalyst, which can be used in the invention's process, is a strong mineral protic acid, a suphonic acid, an acidic zeolite or a Lewis acid. By “mineral” we mean here an acid having an anion which does not contain a carbon atom. By “strong” we mean here a protic acid having a pK AB <3, preferably below 2.
[0022] The catalyst can be in the anhydrous form or also in the hydrate form, except for those acids which are unstable in the presence of water.
[0023] According to another particular embodiment of the invention, the catalyst is selected from the group consisting of H 2 SO 4 , p-toluenesulphonic acid, NaHSO 4 , KHSO 4 , H 3 PO 4 , HCl, HNO 3 , BF 3 and its adducts with C 2-6 ethers or with C 2-6 carboxylic acids, poly(styrene sulphonic acid) based resins, K-10 Clay, SnX 4 , FeX 3 and ZnX 2 , X representing a halogen atom, such as Cl or Br, or a C 1-6 carboxylate, such as acetate or trifluoroacetate, or a C 1-7 sulphonate, such as a triflate or tosylate.
[0024] Preferably, the catalyst is H 3 PO 4 , FeX 3 or ZnX 2 .
[0025] The catalyst can be added to the reaction medium in a large range of concentrations. As non-limiting examples, one can cite catalyst concentrations ranging from 0.001 to 0.30 molar equivalents, relative to the molar amount of the starting compound (II). Preferably, the catalyst concentrations will be comprised between 0.005 and 0.15 molar equivalents. It goes without saying that the optimum concentration of catalyst will depend on the nature of the catalyst and on the desired reaction time.
[0026] Another parameter of the invention's process is the temperature. In order to allow the cyclization to occur, it is useful to carry out the invention's process at a temperature of at least 10° C. Below this temperature the speed of the reaction decreases quite rapidly. The upper limit of temperature range is fixed by the reflux temperature of the reaction mixture that, as skilled persons know, depends on the exact nature of the starting and final product and optionally, as explained below, of the solvent. However, as non-limiting example, one can cite a preferred temperature ranging between 60° C. and 180° C. Of course, a person skilled in the art is also able to select the preferred temperature as a function of the melting and boiling point of the starting and final products as well as of the solvent.
[0027] The process of the invention can be carried out in the presence or in the absence of solvent. As a person skilled in the art can anticipate, the presence of a solvent is mandatory only in the case in which the starting compound is a solid compound under the reaction conditions.
[0028] According to a preferred embodiment of the invention, and independently of the physical state of the starting compound, the process is advantageously carried out in the presence of a solvent. Preferably, the solvent is anhydrous or does not contain more than 5% w/w water.
[0029] Non-limiting examples of such a solvent are C 4 -C 8 ethers, C 3 -C 6 esters, C 3 -C 6 amides, C 6 -C 9 aromatic solvents, C 5 -C 7 linear or branched or cyclic hydrocarbons, C 1 -C 2 chlorinated solvents and mixtures thereof.
[0030] Furthermore, the reaction can also be carried out in the presence of a solvent belonging to the family of carboxylic anhydride of formula R 2 C(O)O(O)CR 2 , R 2 being defined as above, optionally containing the corresponding carboxylic acid R 2 COOH.
[0031] The compound of formula (II) can be made and isolated according to any prior art method. Alternatively, compound (II) can be also generated in situ, i.e. in the reaction medium just before its use, according to any know prior art method. In particular, preferably the compound of formula (II) is made or generated by a method using the corresponding enal as starting material. Indeed, the enal can be easily obtained by an aldolic condensation, as a person skilled in the art knows well.
[0032] Therefore, another object of the present invention is an invention's process, as defined above, further comprising the step of generating in situ the compound of formula (II) starting from the corresponding enal of formula
wherein R 2 , R 3 , R 4 and R 5 have the same meaning indicated above.
[0033] A process comprising the in situ generation of the compound of formula (II) is particularly useful when the compound (II) is an acetal or an acylal, the latter being a geminal dicarboxylate.
[0034] Now, when the compound of formula (II) is an acylal, we have also noticed that the catalysts that are able to promote the cyclization of the acylal are also useful to promote the conversion of the enal into the corresponding acylal.
[0035] Therefore, another object of the present invention, and in fact a particular embodiment of the above-mentioned process, is a process for making an ester of formula (I), as defined above, comprising the step of reacting, in the presence of a catalyst as defined for the cyclization step, an enal of formula (III), as defined above, with a carboxylic anhydride of formula R 7 C(O)O(O)CR 7 , wherein R 7 , taken separately, represents a R 2 group as defined above or the R 7 , taken together, represent a R group as defined above.
EXAMPLES
[0036] The invention will now be described in further detail by way of the following examples, wherein the abbreviations have the usual meaning in the art, the temperatures are indicated in degrees centigrade (° C.). The NMR spectral data were recorded in CDCl 3 at 400 MHz or 100 MHz for 1 H or 13 C, respectively, the chemical displacements 8 are indicated in ppm with respect to TMS as standard, and the coupling constants J are expressed in Hz. All the abbreviations have the usual meaning in the art.
Example 1
Cyclization of 2-alkylcinnamic aldehyde via the acylal derivative
a) Preparation of 2-pentyl-1H-inden-1-yl acetate
[0037] 4.13 ml of a 0.25 M solution of FeCl 3 , 6H 2 O in Ac 2 O (1.03 mmol) where diluted into Ac 2 O (30.2 g) and the resulting solution was added dropwise during 1 hour to a stirred solution of 2-pentylcinnamaldehyde (20 g, 99 mmol) in AcOH (18.5 g) at reflux. After a further 2 hours at reflux the cooled mixture was poured into a mixture of H 2 O and Et 2 O. Then, solid Na 2 CO 3 (44.7 g) was added portionwise to the stirred mixture. After one hour stirring the aqueous phase was saturated with NaCl and extracted with Et 2 O. The organic layers were dried over anhydrous Na 2 SO 4 , and the solvent evaporated to afford a crude product, which was further purified by distillation in vacuum to give the desired compound (yield=87%).
[0038] B.p. 86-93°/0.05 mbar
[0039] 1 H-NMR: 0.90 (br.t, J=7, 3H); 1.35 (4H); 1.58 (m, 2H); 2.17 (s, 3H); 2.29 (m, 2H); 6.21 (s, 1H); 6.43 (s, 1H); 7.09 (dd, J=7, J=7, 1H); 7.13 (d, J=7, 1H); 7.23 (m, 1H); 7.37 (d, J=7, 1H)
[0040] 13 C-NMR: 171.4(s); 149.2(s); 143.7(s); 142.0(s); 128.9(d); 128.2(d); 125.1(d); 124.2(d); 120.4(d); 77.5(d); 31.6(t); 28.2(t); 27.7(t); 22.5(t); 21.1(q); 14.0(q)
b) Preparation of 2-hexyl-1H-inden-1-yl acetate
[0041] Using the same experimental procedure as under a), 2-hexylcinnamaldehyde (20 g, 92.6 mmol), FeCl 3 , 6H 2 O (3.85 ml of a 0.25 M solution in Ac 2 O, 0.96 mmol), Ac 2 O (28.3 g, 0.28 mol) in AcOH (17.4 g) were reacted together. After a further 3 hours at reflux the cooled mixture was treated to the same workup as before to provide the title compound (yield=83%)
[0042] B.p. 89-101°/0.035 mbar
[0043] 1 H-NMR: 0.89 (t, J=7, 3H); 1.25-1.40 (6H); 1.58(m, 2H); 2.17 (s, 3H); 2.29 (m, 2H); 6.21 (s, 1H); 6.43 (s, 1H); 7.09 (dd, J=7, J=7, 1H); 7.13 (d, J=7, 1H); 7.22 (m, 1H); 7.36 (d, J=7, 1H)
[0044] 13 C-NMR: 171.4(s); 149.3(s); 143.7(s); 142.0(s); 128.9(d); 128.2(d); 125.1(d); 124.2(d); 120.4(d); 77.5(d); 31.7(t); 29.1(t); 28.3(t); 28.0(t); 22.6(t); 21.1(q); 14.1(q)
c) Preparation of 2-methyl-1H-inden-1-yl acetate
[0045] Using the same experimental procedure as under a), 2-methylcinnamaldehyde (21 g, 0.14 mol) in AcOH (27 g), FeCl 3 -6H 2 O (6 ml of a 0.25 M solution in Ac 2 O, 1.5 mmol) in Ac 2 O (53 g) were reacted together. After a further 2 hours at reflux the cooled mixture was treated to the same workup and purification as before to provide the title compound (yield=70%)
[0046] B.p. 70-95°/0.04 mbar.
[0047] 1 H-NMR: 1.98 (s, 3H); 2.18 (s, 3H); 6.15 (s, 1H); 6.41 (s, 1H); 7.09 (dd, J=7, 7, 1H); 7.12 (d, J=7, 1H); 7.23 (m, 1H); 7.37 (d, J=7, 1H)
[0048] 13 C-NMR: 171.5(s); 144.4(s); 143.7(s); 142.1(s); 129.3(d); 128.9(d); 125.1(d); 124.2(d); 120.3(d); 78.4(d); 21.1 (q); 14.0(q)
Example 2
a) Preparation of 1-methoxy-2-methyl-1H-indene via cyclization of the acetal
[0049] A solution of FeCl 3 anhydrous (42 mg, 0.25 mmol) in BuOAc (4 ml) was added dropwise during 10 minutes to a stirred solution of the 3,3-dimethoxy-2-methyl-1-phenyl-1-propene (5 g, 24.7 mmol) in BuOAc (13 ml) at 123° C. After 3 hours the cooled mixture was diluted with Et 2 O (50 ml) and washed with saturated aqueous NaHCO 3 and brine. Extraction, drying over anhydrous Na 2 SO 4 , concentration and fractional distillation in vacuum gave a crude product that was further purified by chromatography (SiO 2 , cyclohexane/AcOEt 95:5 then AcOEt/Et 2 O 1:1). There was thus obtained the title compound with a yield of 33%.
[0050] B.p. 32-43° 0.07 mbar
[0051] 1 H-NMR: 2.03 (s, 3H); 3.03 (s, 2H); 4.85 (s, 1H); 6.44 (s, 1H); 7.09 (dd, J=7, J=7, 1H); 7.11 (d, J=7, 1H); 7.22 (m, 1H) 7.41 (d, J=7, 1H)
[0052] 13 C-NMR: 145.9(s); 143.9(s); 141.8(s); 128.7(d); 128.4(d); 124.6(d); 123.7(d); 120.1(d); 84.9(d); 51.8(q); 14.1(q)
b) Preparation of 2-methyl-1H-inden-1-yl acetate via cyclization of the acylal
[0053] A solution of FeCl 3 anhydrous (21 mg, 0.125 mmol) in BuOAc (2 ml) was added dropwise during 5 minutes to a stirred solution of the 2-methyl-3-phenyl-2-propenylidene diacetate (3.1 g, 12.5 mmol) in BuOAc (8 ml) at 123°. After 2 h at 123° the reaction was stopped and worked-up as above. Chromatography (SiO 2 , cyclohex/AcOEt 9:1) of the crude product allowed the isolation of the title acetate (62% yield). Identical spectra as previously described.
Example 3
Synthesis of 2,6-dimethyl-1H-inden-1-yl acetate from the corresponding aldehyde
[0054] A solution of (2E)-2-methyl-3-(4-methylphenyl)-2-propenal (100.0 g, 0.62 mol) in cyclohexane (300.0 g) was added dropwise in 2 hours to a stirred solution of zinc chloride (3.1 g, 22 mmol) in acetic anhydride (188.4 g, 1.85 mol) at 80° C. The reaction mixture was stirred further at 80° C. for 18 hours and then cooled to 25° C. The mixture was washed twice with water (100.0 g) and a 5% aqueous solution of sodium carbonate (100.0 g) and concentrated under reduced pressure. The crude product was flash-distilled (B.p.: 75-90° C./0.1 mbar) affording 88.5 g of the desired acetate (69%) as a yellow liquid (purity: 97.1% GC).
[0055] 1 H-NMR: 7.19 (s, H); 7.03 (d, J=7.9, H); 6.99 (d, J=7.9, H); 6.37 (s, H); 6.11 (s, H); 2.31 (s, 3H); 2.17 (s, 3H); 1.95 (s, 3H).
[0056] 13 C-NMR: 171.5 (s); 143.3 (s); 142.3 (s); 141.0 (s); 134.8 (s); 143.3 (s); 129.2 (d); 125.2 (d); 120.0 (d); 78.4 (d); 21.3 (q); 21.1 (q); 14.0 (q).
Example 4
Synthesis of 2,6-dimethyl-1H-inden-1-yl acetate from the corresponding aldehyde
[0000] General Procedure
[0057] A solution of (2E)-2-methyl-3-(4-methylphenyl)-2-propenal (100.0 g, 0.62 mol) in acetic anhydride (100.0 g) was added dropwise in 2 hours to a stirred solution of the catalyst in acetic anhydride (88.4 g, 1.85 mol in total) at 80° C. The reaction mixture was stirred further at 80° C. until the complete conversion of the starting material and then cooled to 25° C. The mixture was diluted with methyl tert-butyl ether (300.0 g), washed successively with water (twice 100.0 g) and a 5% aqueous solution of sodium carbonate-(100.0 g) and concentrated under reduced pressure. The crude product was flash-distilled (B.p.: 75-90° C./0.1 mbar) affording the desired acetate as a yellow liquid.
[0058] The results obtained are listed in the following table:
Catalyst Reaction time Isolated yield H 3 PO 4 (0.072 eq.) 22 h. 51% BF 3 .OEt 2 (0.036 eq.) 19 h. 37% ZnBr 2 (0.036 eq.) 5 h. 55% eq. = molar equivalents in respect to the starting material h = hours
Example 5
Synthesis of 1-ethoxy-2-butyl-1H-indene from the corresponding aldehyde
[0059] A mixture of 2-butylcinnamic aldehyde (5 g, 26.7 mmol.), triethyl orthoformate (5.9 g, 40 mmol.), absolute ethanol (10 g, 217 mmol.) and Amberlyst® 15 (0.52 g) was heated at reflux (85° C. oil bath). After three days, the mixture was filtered and concentrated under vacuum. The residue % as subjected to silica gel flash chromatography (hexane/ethyl acetate 98:2), yielding 3.8 g (17.6 mmol., 66% yield) of the indenyl ethyl ether.
[0060] 1 H-NMR: 0.95 (t, J=7.4, 3H), 1.15 (t, J=6.9, 3H), 1.46-1.36 (m, 2H), 1.70-1.50 (m, 2H), 2.45-2.30 (m, 2H), 3.27-3.15 (m, 2H), 4.95 (s, 1H), 6.41 (s, 1H), 7.1 (t, J=7.2, 1H), 7.13 (d, J=7.2, 1H), 7.21 (t, J=7.2, 1H), 7.42 (d, J=7.2, 1H).
[0061] 13 C-NMR: 14.0 (q), 15.7 (q), 22.7 (t), 28.1 (t), 30.5 (t), 60.0 (t), 83.4 (d), 120.2 (d), 123.7(d), 124.6 (d), 126.9 (d), 128.3 (d), 142.5 (s), 143.6 (s), 151.3 (s).
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The present invention relates to a process for making indenol esters or ether from an α-substituted cinnamic aldehyde derivative such as an acetal or an acylal. This reaction is promoted by the use of strong mineral acids, sulphonic acids, acidic zeolites or Lewis acids.
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This is a divisional application of Ser. No. 10/453,214, filed Jun. 3, 2003, entitled PRESSURE MONITORING TECHNIQUE AND APPLICATIONS INVOLVING WELLS, now U.S. Pat. No. 6,910,375.
This invention relates to a method and apparatus for monitoring pressure and, more particularly, to applications of pressure monitoring in hydrocarbon wells.
BACKGROUND OF THE INVENTION
The equipment used in drilling, completion and working over of hydrocarbon wells in the past has almost entirely been a matter of brute force rather than finesse. Drilling rigs in particular and workover rigs to a lesser extent are characterized by massive machinery, high horsepower pumps and a brute force approach to problems. In contrast, coiled or spooled tubing units are much more finesse oriented because the pipe that comprises the work string is much smaller, much thinner and much less capable of accommodating large forces. At one time, coiled tubing units were widely known as an invitation to a fishing job because there were so many mechanical failures of the work string or the loss of bottom hole components in wells.
It is a tribute to the manufacturers of coiled tubing and coiled tubing equipment and a tribute to operators of coiled tubing equipment that the reliability of coiled tubing operations has increased dramatically over the years. In addition, the relative attractiveness of coiled tubing operations as compared to conventional workover rig operations has improved substantially to the extent that coiled tubing units have taken considerable market share from workover rigs in the completion and reworking of hydrocarbon wells.
So called pressure snubbers are known in the art and are used between a fluctuating pressure source and a gauge to protect the gauge from pressure spikes and to damp pressure fluctuations. These devices comprise a fitting having a porous metal insert or a single perforation. A gauge or pressure sensor is threaded into the fitting.
Relevant to this invention are the disclosures in U.S. Pat. Nos. 3,749,185; 4,297,880; 6,109,367 and 6,421,298.
SUMMARY OF THE INVENTION
In one aspect of this invention, a pressure source, such as a pump, provides an output pressure that fluctuates widely and rapidly. In order to provide pressure sensings that are meaningful, a pressure measuring conduit connects to the pressure source and includes a damper, leaving the main flow line of the pressure source undamped. The damper reduces the fluctuations of the output pressure to less than 1% of the average outlet pressure and preferably much less. The damped pressure is sensed by a conventional sensor and displayed on a screen in real time so the user can make decisions based on the damped pressure sensings. The values are preferably displayed as time versus damped pressure so the trends may be readily seen and action taken in response to the trends seen. This is particularly important when actions occur in response to pressure differentials that are smaller than or masked by the pressure fluctuations. This situation may occur in many environments, such as in the use of downhole tools in hydrocarbon wells which are powered or manipulated by hydraulic pressure supplied from the surface. Many other applications will become apparent to those skilled in the art.
In another aspect of this invention, a particularly effective and inexpensive damper is described, comprising a pair of needle valves in series. It is not clear exactly why a pair of needle valves are so effective in damping pressure fluctuations. Although not wishing to be bound by any theory of operation, a theory will be advanced hereinafter. Because the needle valves are adjustable, the size and shape of openings are adjustable. It is clear that opening the needle valves completely reduces their damping effectiveness.
In another aspect of this invention, operation of a downhole motor is monitored and decisions made in response to a pressure differential between the pump pressure supplied at a time when the motor is idling and when the motor is under load. In a typical situation, the motor is equipped with a bit or mill for drilling. When the motor is approaching a stall, or being significantly overloaded, this pressure differential increases in a manner that is recognizable. Stalling a turbine type liquid driven motor is never desirable for a variety of reasons, including wear on resilient parts on the inside of the motor or, as described more fully below, the fatigue on a coiled tubing work string.
It is an object of this invention to provide an improved method and apparatus for monitoring pressure.
Another object of this invention is to provide a method and apparatus for sensing pressure of a source which fluctuates widely and rapidly.
A further object of this invention is to provide applications for pressure monitoring techniques that involve operating downhole tools and equipment in hydrocarbon wells.
These and other objects of this invention will become more fully apparent as this description proceeds, reference being made to the accompanying drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified prior art chart of time versus pressure showing the fluctuation of conventional high pressure multiplex pumps;
FIG. 2 is a schematic view of the pressure monitoring system of this invention;
FIG. 3 is an exploded view of the pressure damper and pressure sensor;
FIG. 4 is a schematic view relating to a theory of operation of the pressure damper;
FIGS. 5 and 6 are pictorial views of a display of this invention; and
FIG. 7 is a graph illustrating the effectiveness of this invention.
DETAILED DESCRIPTION
The discharge pressure of high pressure multiplex pumps used to power or manipulate downhole tools in hydrocarbon wells fluctuates so widely and so rapidly that pertinent pressure changes are often masked by, or are smaller than, the fluctuations. This is illustrated in FIG. 1 which is a graph of time versus pressure taken downstream of a conventional pressure snubber that is supposed to damp pressure fluctuations. Every pump acts slightly differently and the fluctuations vary with the operating speed of the pump and other factors. Basically, however, every time the discharge valve of a high pressure multiplex pump opens, a surge of high pressure liquid leaves the pump producing an upward pressure spike. Because most liquids range from mainly incompressible to slightly incompressible, the pressure surges dissipate as the liquid moves down the flow line into which it is discharged. This causes a reduction in pressure at the pump outlet until the next discharge valve opens.
This invention was developed, and will be described, in conjunction with the operation of so called mud motors, i.e. downhole motors operated by high pressure liquids, gases or mixtures pumped through a work string extending into a hydrocarbon well. These motors will be described using a liquid but it will be understood that gases or mixtures are equally useable. The term mud motor is often misleading because, except in a drilling rig, it is not mud that is pumped down the work string but a liquid, gas or mixture that is clearly not drilling mud. A better name is a hydraulic motor.
It is recognized that this invention has considerable utility in other applications, particularly the operation of other downhole tools, such as the setting of whipstocks, setting of packers, pumping wiper plugs during cementing operations, setting of liners and other situations where downhole tools are operated or manipulated by hydraulic pressure delivered from the surface. In addition, the invention is useful in other operations relating to hydrocarbon wells such as the monitoring of flow from a well which has been recently stimulated. Other applications outside the field of hydrocarbon wells will be apparent to those skilled in the art.
Hydraulic motors are widely used in drilling deviated wells, in completing hydrocarbon wells and in reworking hydrocarbon wells. Many of such motors are of a size and operated on the end of such robust work strings that they and the work strings can take considerable abuse. Hydraulic motors used on coiled or spooled tubing units are in a different category because the coiled tubing work strings are not robust and must be handled with care for a variety of reasons, one of which is to prevent failure due to fatiguing of the metal from which the tubing is made. In addition, mud motors used on coiled tubing strings are usually used inside casing and therefore are typically of smaller diameter and therefore less robust than motors used on drilling rigs.
Referring to FIGS. 2–5 , this invention is described in conjunction with a coiled tubing unit being used to drill out a bridge plug, which is a common application of this invention. A typical hydrocarbon well 10 comprises a bore hole 12 drilled into the earth to penetrate one or more hydrocarbon bearing formations 14 , 16 . A pipe string 18 is cemented in the earth by a cement annulus 20 . Perforations 22 , 24 have been created to communicate the formations 14 , 16 with the inside of the pipe string 18 . A bridge plug 26 , cement plug 28 and sand bridge 30 have been placed between the formations 14 , 16 to isolate them temporarily, as is commonly done during completion of the well 10 where the formations 14 , 16 are separately fraced.
A coiled tubing unit 32 of any suitable type is illustrated as suspending a string of coiled tubing 34 in the well providing a hydraulic motor 36 and a bit or mill 38 on the lower end for circulating out the sand bridge 30 and drilling up the cement plug 28 and the bridge plug 26 . The coiled tubing 34 is taken off a spool 40 and run over a wheel or arc support 42 and guided by an arcuate support (not shown) and forced into the well 10 by a conventional injection head 44 . A typical example of the care given to the treatment of coiled tubing 34 is that the tubing is allowed to cycle over the wheel or arc support 42 only a small number of times because experience has shown this is the location where fatiguing of the metal occurs. The number of cycles before failure is largely a function of pressure inside the coiled tubing and, for example, above 7000 psi, the number of cycles is limited by safety considerations to between ten and twenty. If a cycle limit is reached, the coiled tubing 34 is pulled from the well 10 and a quantity of tubing is cut off the lower end so the next time the tubing is run into the well, a different section of tubing is supported on the wheel 42 .
All of this activity is expensive, partly due to the pricing policy of coiled tubing unit owners justified by wear and tear on the coiled tubing 34 and partly due to the time and effort necessary to pull the tubing from the well, detach the bottom hole assembly 36 , 38 , cut the tubing, reattach the bottom hole assembly and run back into the well. In any event, it is highly desirable to minimize the number of times the coiled tubing 34 is moved over the wheel 42 .
When a motor 36 is used on the end of a coiled tubing string 34 to drill up a downhole component in a hydrocarbon well, there are many times when the coiled tubing must be pulled up and down, or cycled, over the wheel 42 . A very common occurrence is when too much weight is applied to the motor, as may occur when trying to washout the sand bridge 30 or drill the plugs 26 , 28 too rapidly. Relying on conventional pressure readings shown in FIG. 1 is useless either because pertinent pressure information is masked by the fluctuations or because the time delay of prior art equipment results in a tool operating before pressure readings are obtained. Thus, prior art operation of hydraulic motors on the end of coiled tubing is largely a matter of feel, experience and intuition, all of which are difficult and expensive to teach and learn. Much learning comes from failures but failure to pick up the coiled tubing 34 and applying too much weight stalls the motor and potentially damages or ruins it. The lesser evil, i.e. picking up too often on the coiled tubing 34 to slow down drilling, cycles the tubing over the arc support 42 too frequently and fatigues the coiled tubing which must be removed from the well, cut off and run back into the well, at great expense.
As shown in FIG. 2 , a pump 46 delivers high pressure liquid through a main flow line 48 into the coiled tubing 34 in a conventional manner. Pressure in the flow line 48 is undamped and fluctuates as shown in FIG. 1 . A pressure fitting 50 on the flow line 48 connects to a damper 52 which connects to a suitable pressure sensor 54 . The function of the damper 52 is to damp the pressure fluctuations shown in FIG. 1 to an extent that pertinent pump pressure changes are not masked by the fluctuations. Because the damper 52 is not in the main flow line 48 , there is no energy loss in the damping process which is typical of situations where the entire flow stream is damped, as in the case of mud pumps on drilling rigs.
To this end, the damper 52 is of a type that damps the fluctuations so they do not exceed 1% of the average pump pressure, preferably so they do not exceed ½ of 1% of the average pump pressure and ideally so they do not exceed 0.2% of the average pump pressure. Thus, on a typical drilling job with a coiled tubing unit where pump pressure may be on the order of 10,000 psi, the fluctuations are damped to be less than 100 psi, preferably less than 50 psi and ideally less than 20 psi.
Although many designs of dampers may be effective to this extent, a preferred approach is shown in FIGS. 3 and 4 where the damper 52 comprises a pair of conventional needle valves 56 placed in series. The needle valves 56 each comprise a valve body 58 having a rotatable handle 60 for advancing a pointed valve element into and through a passage 62 . The housing 58 typically has a male end 64 at one end and female threads in the other end.
Although not being bound by any particular theory of operation, FIG. 4 illustrates what is thought to be happening. On the left or upstream end of FIG. 4 , there are large pressure waves suggesting the fluctuations shown in FIG. 1 . Between the valve bodies 58 in the flow passage or cavity between the needle valves 56 , there is a reduction in the magnitude of pressure waves because the waves have to pass through the small opening 62 of the upstream valve body 58 . Downstream of the right or downstream valve body, there are smaller pressure waves than in the cavity between the valve bodies 58 because the pressure waves have to travel through the small opening 62 in the downstream valve body 58 . In this fashion, the wildly fluctuating pump pressure of FIG. 1 is damped so substantially that no comparable fluctuations are apparent on the display screen used to show a trace of pump pressure. The effect of the second flow restriction is seen most clearly by reducing the flow passage through the upstream valve, viewing the pressure fluctuations and then reducing the flow passage through the downstream valve. When the first valve is restricted, the pressure pulses seen by the sensor 54 are smaller but still pronounced. Restricting the downstream valve reduces the pressure pulses dramatically to a range of 3–20 psi.
The pressure sensor 54 may be of any suitable type and is conveniently Model MSP-300 obtained from Measurement Specialties, Valley Forge, Pa. This particular sensor is an analog sensor which necessitates the user of an analog-to-digital converter as will be more fully apparent hereinafter.
Referring to FIG. 2 , an output 66 from the pressure sensor 54 connects to a data logger assembly 68 which is conveniently portable. The data logger assembly 68 includes an analog-to-digital converter 70 connected to a microprocessor 72 . A real time clock 74 provides another input to the microprocessor 72 so that pressure readings obtained from the sensor 54 can be matched with the time when they are taken. The microprocessor 72 may be controlled by suitable software to accept pressure data at predetermined intervals, such as one second or any other suitable interval. A memory device 76 is provided to temporarily store data. An output 78 from the microprocessor 72 operates a transmitter 80 to deliver time/pressure data to a graphical display assembly 82 . The transmitter 80 is preferably wireless using convenient technology such as a low power radio frequency approach.
The graphical display assembly 82 may be of any suitable type, such as a computer screen or a special purpose, display of a size small enough to carry easily. The display assembly 82 comprises a receiver 84 receiving communication from the transmitter 80 , a microprocessor 86 , a memory device 88 , a user input 90 and a display 92 . The display 92 is typically a computer monitor or other suitable electronically manipulated screen. It will accordingly be seen that time/pressure data from the transmitter 80 passes through the receiver 84 into the microprocessor 86 and is stored in the memory device 88 . The microprocessor 86 delivers data to the display 92 at suitable intervals to construct a time/pressure trace 94 , as shown in FIG. 5 , indicative of damped pressure readings from the sensor 54 .
In coiled tubing operations of the type described, it is often desirable to know the pressure at the surface in the annulus between the coiled tubing 34 and the pipe string 18 . To this end, a pressure fitting 96 is attached to the wellhead 98 and provides a pressure sensor 100 having an output 102 connected to an analog-to-digital converter 104 in the data logger assembly 68 . Pressure in the annulus measured by the sensor 100 typically does not fluctuate significantly so no damper is necessary. The components of the assembly 68 are sufficiently capable to accommodate additional data, so the data transmitted to the graphical display device assembly 82 includes a stream of time/pressure information indicating pressure in the annulus. This data is stored in the memory device 88 and shown on the display 92 as a second trace 101 , as shown in FIG. 5 .
The absolute value of the pressure in the annulus normally depends on the size of the choke (not shown) used to control flow from the well 10 . The absolute value of the pressure in the annulus, unless the well is blowing out, is typically less than the pump pressure measured by the sensor 54 . The scale of the pressure trace 101 is thus typically much lower than the scale of the trace 94 , meaning that the display 92 may simultaneously show two separate pressure scales. In a typical bridge plug drilling operation, the pressure trace 94 may be shown on a scale of 6000–8000 psi while the pressure trace 101 may be on a scale of 1000–3000 psi as shown by suitable lines and/or indicia (not shown) on the display 92 . The microprocessor 86 detects when pressure readings rise above or below the scale being used on the display 92 and adjusts the scale accordingly by shifting the scale up or down to make room for the trace. Similarly, when the traces 94 , 101 approach the right side of the display 92 , the pressure traces 94 , 101 are shifted to the left to provide room for additional data.
The display 92 , as shown in FIG. 5 , also preferably provides a series of boxes on one side. The box 106 conveniently shows the last pump pressure reading, the box 108 shows the last annulus pressure reading, the box 110 shows the last pressure differential reading as will be explained more fully hereinafter and the box 112 shows a voltage reading of the battery (not shown) used to operate the graphical display assembly 82 and thus suggests when the battery needs to be replaced.
An important feature of this invention is that the pressure traces 94 , 101 and the values in the boxes 106 – 112 are in real time, i.e. current time/pressure data being captured by the microprocessor 72 shows up as an addition to the traces 94 , 101 in short order, typically in a second or two. Thus, the person in charge of the operation and the person controlling the pump 46 and the injection head 44 have the capability of watching real pump and return pressures in real time and adjust operation of the pump 46 and or the coiled tubing unit 32 in response to events as they occur. Often, the trend of the pressure curves provides important clues about what is happening in the well 10 and allows the users to adjust in response to conditions as they occur and are reflected in pump and return pressure. For example, if coiled tubing 34 is being fed into the well 10 at the depth of the sand bridge 30 , a rise in pump pressure at 114 indicates that the torque on the motor has increased and, in this context, typically means that weight is being applied to the bit 38 and the subsequent fall in pump pressure at 116 indicates that the sand bridge 38 is being washed away or being drilled.
Often, the relationship between the trends in pump and return pressure suggests an explanation for events that are occurring in the well 10 . For example, if both pressure traces 94 , 101 are falling slightly at a time when washing or drilling a plug, it likely means a lower pressure zone has been exposed. The exact meaning of any pressure changes seen on the display 92 will always depend on the context of what is happening.
As suggested previously, an important application of this invention is in operating a hydraulic motor used in a drilling application, such as shown in FIG. 2 . As mentioned previously, too much weight on the bit 38 causes increased load on the motor 36 and ultimately causes it to stall. In the prior art, when the motor is in the process of stalling, it is not apparent until the pump outlet pressure rises dramatically which occurs well after the motor has stalled. What is difficult is detecting when the motor is beginning to stall. The delay in realizing the motor has stalled is aggravated because the fluctuations in pump pressure are greater than the pressure variation that indicates the motor has stalled. For example, the fluctuations shown in FIG. 1 can easily be 300–500 psi when the average pump pressure is 7000 psi, i.e. the fluctuations can easily be in the range of 5–10% of the average pump pressure.
When a hydraulic motor goes from an idling condition to a loaded condition, there is a pressure increase on the inlet side of the motor because the motor is loaded and the force generated by the motor is converted from the pressure drop across the motor. When a hydraulic motor stalls, the pressure at the motor inlet increases further. The motor inlet pressure that signals stalling depends on the size of the motor, how much the motor is worn and a variety of other factors, many of which change while a motor is being used and before it is retrieved from a well.
Referring to FIG. 6 , a pressure trace 118 is a typical example of what happens to pump pressure as the bit 38 is lowered onto a solid drillable object, such as the cement plug 28 or the bridge plug 26 . At the outset, as at 120 , the motor 36 is idling and the pump pressure is relatively stable over time. As the bit 38 is lowered onto the cement plug 28 , the pump pressure rises as shown at 122 suggesting the bit 38 is loaded and drilling on the cement plug 28 . Often, the bit 38 will drill off, i.e. it will drill faster than it is being lowered, and the pump pressure will decline slightly as shown at 124 and ultimately stabilize at 126 where the coiled tubing 34 is being lowered at the same rate as the cement plug 28 is being drilled. It will be seen that the absolute pressure in the region 126 is higher than in the region 124 indicating that the motor 36 is under load, which is what one would expect when the motor 36 goes from idling to under load.
In the event the coiled tubing 34 is lowered too rapidly, the pump pressure rises as at 128 , suggesting an imminent stalling of the motor 36 . At this time, the coiled tubing operator would manipulate the injection head 44 to either quit lowering the coiled tubing 34 or raise the coiled tubing 34 to quit drilling. The pressure necessary to stall a motor 36 of the type used on coiled tubing units 32 varies somewhat but a 200 psi pressure rise would be sufficient in many cases to stall the motor. Such a pressure rise is well below the fluctuations inherent in a high pressure multiplex pump so it would be completely masked to the coiled tubing unit operator.
In one aspect of this invention, the differential pressure is displayed in box 110 or a trace 130 of differential pressure is provided to assist in detecting an incipient stall of the motor 34 . The differential pressure displayed in box 110 or the trace 130 is a pressure differential P 2 −P 1 where P 1 is the pressure when the motor 36 is idling and P 2 is the instantaneous pressure of the motor 36 . To set the differential pressure trace 130 and to zero the instantaneous pressure differential shown in box, the user input 90 , shown as a depressible button in FIGS. 5 and 6 , is depressed at a time when the motor 36 is idling, i.e. during the interval 120 on trace 118 . This sets a value for P 1 until the next time the user input 90 is actuated.
The pressure trace 130 will be seen to be an exaggeration of the pressure trace 118 over short intervals of time unless the scale of the trace 118 is itself exaggerated. Thus, experienced users of this invention are capable of using the pressure traces 94 , 118 to determine the onset of motor stall and take appropriate action without use of the trace 130 .
Typically however, when the motor 36 begins to stall, for whatever reason but typically due to too much weight on the bit 38 , the coiled tubing operator makes decisions based on the trace 118 or the trace 130 to take weight off the bit 38 either by stopping or slowing the lowering of the coiled tubing 34 into the well or by raising the coiled tubing 34 if necessary. It will be seen that using the trace 118 or the trace 130 allows the coiled tubing operator to reduce the number of times the coiled tubing 34 is raised, thereby reducing the cycling of the coiled tubing over the wheel 42 .
This is an important advance in the operation of coiled tubing units because it reduces cycling of the coiled tubing and reducing unnecessary wear on downhole hydraulic motors thereby reducing the costs of coiled tubing operations.
Referring to FIG. 7 , there is illustrated a test of a turbine motor drilling a window in casing after a whipstock was set. This test was conducted in a test jig located at the surface so the absolute pressure values are much lower than would be expected in a downhole application where the surface pump has to overcome the hydrostatic pressure of the motive fluid. A characteristic of a turbine motor is that when it stalls, the motive fluid basically bypasses the turbine so the surface pump pressure falls off substantially. The pump was run continuously for slightly more than eight minutes.
FIG. 7 provides a single trace 132 of pump pressure and illustrates several areas 134 where the damping valves 56 of this invention have been intentionally opened so the damping system is not operative and several areas 136 where the damping valves 56 have been manipulated to provide substantial damping. It will be seen that the pressure fluctuations in the undamped areas 134 is in the neighborhood of 600 psi and the pressure fluctuations in the areas 136 are barely discernable on the scale shown and are in the range of 3–20 psi. Just after the turbine motor stalls, the pump pressure falls off. When weight is taken off the bit, the turbine begins drilling and the pressure returns to a more normal value, as shown at area 138 .
Although this invention has been disclosed and described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms is only by way of example and that numerous changes in the details of construction and operation and in the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.
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The outlet pressure of a pump that fluctuates rapidly, as is typical of high pressure multiplex pumps, is sensed in a pressure line leading from the main flow line to a damping mechanism. The damping mechanism comprises a pair of small spaced openings, which are preferably adjustable in size. The damping mechanism is ideally a pair of needle valves placed in series so the pressure downstream of the second needle valve fluctuates considerably less than upstream of the first needle valve. The damped pressure is sensed to provide an input to real time graphs showing various pertinent pressure measurements involving the application of pressure, e.g. to monitor downhole tools in hydrocarbon wells. The downhole tools may be fluid driven motors, whipstocks, packers, wiper plugs and the like. In the case of fluid driven or mud motors, a base line pressure taken when the motor is idling is compared to the pressure when the motor is drilling to detect the onset of motor stall.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
This application is a National Phase Patent Application and claims priority to and benefit of International Application Number PCT/CN2011/076876, filed on Jul. 5, 2011, the entire disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to a method for desorbing and regenerating a butanol-adsorbing resin, especially to a method for desorbing and regenerating a resin with butanol fermentation broth adsorbed therein, and belongs to the technical field of the extraction and purification.
BACKGROUND
Diversification of the country's energy supply is an important aspect of the national energy policy, and the renewable bioenergy will be one of the main energy sources for use in the world's future energy structure. As a new biofuel, butanol has huge market potential with the perfection of upstream and downstream engineering technology for acetone-butanol fermentation industry.
Butanol (n-butanol and 1-butanol) is a four-carbon primary alcohol, with molecular formula of C 4 H 9 OH and molecular weight of 74.12. Butanol is a colorless liquid with a distinct odor, and its vapor exerts an irritative effect on mucous membranes and has anesthetic effects at high concentrations. Butanol is mainly used for manufacture of plasticizers such as dibutyl phthalate and aliphatic dibasic acid butyl ester, and is widely used for manufacture of a variety of plastic and rubber products. Butanol can also be used to produce butyraldehyde, butyric acid, butylamine and butyl acetate, which can be used as solvents of resins, paints and adhesives and can also be used as extractants of oils and fats, drugs and spices and additives of alkyd resin paints. In addition, butanol is also a new biofuel with tremendous potential.
However, there are still many problems with the traditional butanol fermentation industries in terms of large-scale industrial application. Wherein a key problem is the low final concentration of the solvent in the fermentation broth. In the ordinary biological methods for preparing butanol, since butanol has toxic effects on bacteria, the mass concentration of butanol is less than 13 g/L, and the yield of butanol is less than 0.29 g/(L·h), and the output of butanol is less than 25% (by mass), resulting in the total mass percent of the solvent in the fermentation broth less than or equal to 2% accordingly. In order to obtain commercial butanol, it is required to use conventional distillation methods, leading to consumption of large quantities of energy.
In order to solve this critical problem, it is necessary to remove the products of ABE (acetone-butanol-ethanol) from the fermentation broth with an effective method, so as to reduce inhibition on product, thereby enhancing fermentation yield and reducing industrial costs.
Currently, the main techniques for separating fermentation products of ABE include gas stripping (GS), liquid-liquid extraction, pervaporation (PV) and adsorption. Meagher (U.S. Pat. No. 5,755,967) et al. separate acetone and butanol by developing a zeolite membrane filled with silicone rubber according to the pervaporation method. The zeolite membrane has excellent selective adsorption on acetone and butanol relative to the adsorption of ethanol, acetic acid and butyric acid. This patent also reports the thermal analytical method, in which the silicalite is heated to 78° C., and the recovery rate of butanol, acetone and ethanol are 100%, 95.5% and 80% respectively, but there are not reports related to test on solubility of ABE in the elution phase. Qureshi, N. et al. (Qureshi, N. et al, 2005, Bioprocess and Biosystems Engineering, 27(4):215-222) recover biobutanol by the adsorption-desorption method, which is the best recovery process when it comes to energy consumption. DIJK (WO 2008/095896 A1) et al. separate biobutanol using a microporous resin with ultra-high crosslinking degree, however the resin has a certain adsorption capacity for ethanol and acetone, increasing the cost of post-separation process. Arjan Oudshoorn et al. (Arjan Oudshoorn et al, 2009, Biochemical Engineering Journal, 48:99-103) adsorb and separate biobutanol by using a zeolite, and investigate adsorption properties of three zeolites (that is, BV28014, CBV811, CBV901) on biobutanol, however, there are problems that the adsorption capacity of the zeolite on biobutanol is not high and the zeolite also adsorbs acetone and ethanol while adsorbing butanol, resulting in increased cost on separation in later stage. David R. Nielsen et al. (David R. Nielsen et al, 2009, Biotechnology and Bioengineering, 102(3):811-821) recover biobutanol in-situ using a polymer resin and investigate the adsorption property of the polymer resin on biobutanol, but there exists following problems: the resin contacts with the fermentation broth directly, resulting in pollution of the resin; the biocompatibilities of some resins are not good; some resins can absorb the substrate of glucose and fermentation reaction intermediates; the adsorption capacities of some resins are low; although some resins have high adsorption capacity on butanol, they also adsorb a great deal of acetone, ethanol and other substances. Milestone et al. (Milestone, N. B. et al, 1981, J Chem Technol Biotechnol, 31:732-736) desorb butanol from the siliceous rock according to the thermal desorption method in which the siliceous rock is first heated to 40° C. to remove water from the siliceous rock, and then heated to 150° C. to recover butanol with the concentration of butanol in the eluent reaching 790-810 g/L, however, it does not involve report on problems of butanol recovery rate and regeneration method. Das et al. (Das, K. et al, 1987, In: Proceedings 4th European congress on biotechnol, 1: 76-78) realize butanol recovery rate of 60-65%, 75-85% and 75-85% respectively by using 120° C. heated steam through the activated carbon, IRC-50 resin bed and XAD-2 resin bed, wherein the outlet gas is condensed using 0° C. water. In summary, there usually exists two main problems with the current adsorbents for butanol fermentation broth: firstly, the absorption capacity of the adsorbent is low, for example, the absorption capacity is less than 100 mg butanol/g adsorbent; secondly, butanol cannot be desorbed from the adsorbent effectively, resulting in lower overall recovery rate of butanol.
SUMMARY
The first technical problem to be solved by the present invention is: in the prior art, the adsorption capacity of the adsorbent for adsorbing butanol fermentation broth is not high, and the washing solvent used in the desorption method cannot effectively implement dissolving and removing of butanol and other substances in the adsorbent, therefore it is needed to provide a desorption and regeneration method where butanol and other substances in the adsorbent (such as resin) with butanol fermentation broth adsorbed therein can be dissolved effectively and thoroughly through a suitable washing solvent.
The second technical problem to be solved by the present invention is: in the prior art, the adsorbent needs to be taken out from a adsorption-desorption column during regeneration of the resin with butanol fermentation broth adsorbed therein and then loaded into the adsorption-desorption column after regeneration, resulting to in consumption of time and low production efficiency, therefore it is needed to provide a regeneration method suitable for large-scale industrial production where the resin with saturated adsorption of butanol fermentation broth therein can be desorbed directly without taking it out from the adsorption-desorption column.
The third technical problem to be solved by the present invention is: it is needed to consume large quantities of solutions such as organic solvent, acid and base during the regeneration of adsorbents in the prior art, leading to serious pollution and high cost, therefore it is needed to provide a regeneration method where the fixed-bed is eluted with water directly after desorption of the resin with butanol fermentation broth adsorbed therein in the adsorption-desorption column directly to recover the adsorption property of the resin.
In order to solve the above problems, the object of the present invention is to provide a method for desorbing and regenerating a butanol-adsorbing adsorbent to recover butanol and regenerate the adsorbent economically and effectively.
The object of the present invention is implemented by the following technical solution.
In one aspect, the present invention provides a method for desorbing and regenerating a butanol-adsorbing hydrophobic macroporous polymer adsorbent, the method comprises: eluting a hydrophobic macroporous polymer adsorbent with butanol adsorbed therein using a water soluble low-boiling-point polar solvent and water successively. Wherein butanol in the hydrophobic macroporous polymer adsorbent can be desorbed by the water soluble low-boiling-point polar solvent, and then the residual water soluble low-boiling-point polar solvent can be removed by eluting with water, so that the hydrophobic macroporous polymer adsorbent with butanol adsorbed therein can be desorbed and regenerated so as to be continually used for the adsorption of butanol.
Wherein the hydrophobic macroporous polymer adsorbent with butanol adsorbed therein may be a hydrophobic macroporous polymer adsorbent with butanol fermentation broth adsorbed therein, that is, butanol is adsorbed by adsorption of the butanol fermentation broth. The adsorption may be saturated adsorption or may be adsorbed to a certain extent.
Preferably, the method may further comprise: eluting the hydrophobic macroporous polymer adsorbent with water before eluting it with the water soluble low-boiling-point polar solvent. Preferably, eluting the hydrophobic macroporous polymer adsorbent with water is performed at room temperature, preferably 20-25° C., wherein water for elution is used in an amount of 1-2 bed volumes and at a flow rate of 0.5-0.8 bed volumes/hour. In the case that the hydrophobic macroporous polymer adsorbent adsorbs butanol fermentation broth, the residual butanol fermentation broth which is not adsorbed by the adsorbent or some impurities in the fermentation broth can be washed off by this operation.
Preferably, the adsorbent used in the method is a non-polar and/or weak-polar hydrophobic macroporous polymer adsorbent; more preferably, the non-polar hydrophobic macroporous polymer adsorbent has a skeleton of styrene diethylbenzene; the weak-polar hydrophobic macroporous polymer adsorbent has a skeleton of polyacrylamide or styrene diethylbenzene, and has a polar functional group containing nitrogen, oxygen or sulfur.
The adsorbent used in the present invention may comprise the following performances:
the inner surface of the hydrophobic macroporous polymer adsorbent is 100-2000 m 2 /g;
the particle size of the hydrophobic macroporous polymer adsorbent is 20-60 mesh;
the pore diameter of the hydrophobic macroporous polymer adsorbent is 1-180 nm;
the pore volume of the hydrophobic macroporous polymer adsorbent is 0.4-3 cm 3 /g;
the wet apparent density of the hydrophobic macroporous polymer adsorbent is 590-750 g/L;
the water-containing content of the hydrophobic macroporous polymer adsorbent is 40-80%.
In a preferred embodiment of the present invention, butanol is separated by using the following two hydrophobic macroporous resins: one is a non-polar resin, which has a skeleton structure of styrene diethylbenzene without any functional groups, and exerts hydrophobic effect (that is, hydrophobic force) mainly depending on the n-alkyl side chain of butanol and the benzene ring of the skeleton of styrene diethylbenzene; the other is a weak-polar resin, which has a skeleton of polyacrylamide or styrene diethylbenzene and generally has polar functional groups containing nitrogen, oxygen or sulfur such as an amide, cyano or phenolic hydroxyl group, and generates hydrogen bonding force mainly depending on the alcohol hydroxyl group of butanol and the hydroxyl group of the polar functional group in the polar adsorption resin. After the hydrophobic macroporous resin adsorbs the butanol fermentation broth to achieve saturation, the residual unabsorbed liquid is first washed off with water, and then butanol is desorbed from the adsorbent to regenerate the adsorbent according to the desorption and regeneration method of the present invention.
Butanol or butanol fermentation broth is adsorbed by the hydrophobic macroporous polymer adsorbent at a temperature of 10-37° C., preferably 30-37° C. The initial concentration of butanol in the butanol fermentation broth containing butanol is 5-400 g/L.
Furthermore, the butanol used in the method of the present invention is preferably n-butanol.
Preferably, the water soluble low-boiling-point polar solvent used in the method is lower alcohol, ketone, ether, ethyl benzene or ethyl acetate, or a mixture of any two or more solvents selected from the group consisting of lower alcohol, ketone, ether, ethyl benzene and ethyl acetate in any proportion, or a mixture of water with any one or more solvents selected from the group consisting of lower alcohol, ketone, ether, ethyl benzene and ethyl acetate in any proportion;
more preferably, the water soluble low-boiling-point polar solvent is methanol, ethanol, propanol, acetone, ethyl acetate or ethyl benzene, or a mixture of any two or more solvents selected from the group consisting of methanol, ethanol, propanol, acetone, ethyl acetate and ethyl benzene in any proportion, or a mixture of water with any one or more solvents selected from the group consisting of methanol, ethanol, propanol, acetone, ethyl acetate and ethyl benzene in any proportion.
Preferably, in the method, the hydrophobic macroporous polymer adsorbent is eluted with the water soluble low-boiling-point polar solvent at a flow rate of 0.5-10 bed volumes/hour, more preferably 0.6-1.5 bed volumes/hour and in amount of 0.5-10 bed volumes, more preferably 1-4 bed volumes. Moreover, the elution temperature is preferably 10-50° C.; more preferably, the desorption temperature is 20-40° C.
Furthermore, after being eluted with the water soluble low-boiling-point polar solvent, the hydrophobic macroporous polymer adsorbent is eluted with water in amount of 1-2 bed volumes and at a water flow rate of 0.5-1 bed volumes/hour at room temperature.
According to specific embodiments of the present invention, the specific process of the desorption and regeneration method in the present invention may include: first, adsorbing the butanol fermentation broth by a hydrophobic macroporous polymer adsorption resin column to a certain extent (e.g., achieving saturation), then eluting the adsorption bed with a washing agent (water) to remove the unabsorbed fermentation broth at the surface of or in the pore channels of the adsorbents, and draining the washing agent in the adsorption bed, then adding a certain volume of desorbent (i.e. the water soluble low-boiling-point polar solvent of the present invention), and infiltrating for 5 min first, and then desorbing the butanol in the resin phase by the desorbent, and finally eluting the desorbed bed with a regenerate (water) until there is no desorbent in the effluent, then the regeneration is completed, and the next stage of adsorption-desorption operation can be carried out.
The butanol-containing effluent obtained by the desorption and regeneration method of the present invention mainly contains desorbent, butanol and so on, the desorbent with low-boiling-point can be first distilled by distillation to be recycled, and then butanol is distilled at elevated temperature, so that butanol can be obtained by recovery.
Butanol is a hydrophobic and volatile substance, which generates adsorption force mainly by van der Waals forces and hydrogen bond to combine with the adsorbent. In the desorption and regeneration method of the present invention, a water soluble low-boiling-point polar organic solvent is selected to wash the saturated adsorption resin, wherein the polar solvent is selected based on the principle of “like dissolves like”, then butanol and other substances in the saturated adsorption resin are dissolved by washing with a polar organic solvent; a water soluble solvent is selected based on the fact that the water solubility of the solvent enables the residual eluent within the adsorption resin after elution to be easily taken out by water; and use of a low-boiling-point solvent enables the solvent to be recovered easily by distillation; and a polar solvent is selected based on the fact that it not only can dissolve butanol, but also can swell the hydrophobic macroporous adsorption resin so that the adsorption force between the adsorbent and solute (i.e. butanol) can be weakened. Furthermore, different adsorbents have different skeleton structures and functional groups, resulting in different hydrophobic force between the resin and butanol, which affects the adsorption and desorption of the resin. The desorption rate of the hydrophobic macroporous polymer adsorbent obtained by screening in the present invention can reach above 99.3%, while the highest desorption rate of the resin reported is only 85%.
In summary, the main advantages of the present invention are as follows:
(1) a special L-15 resin is used to adsorb butanol in the present invention, the experiments prove that the absorption capacity of the resin on butanol is very high with no by-products such as acetone and ethanol adsorbed.
(2) in the method for desorbing and regenerating a butanol-adsorbing hydrophobic macroporous polymer adsorbent of the present invention, by using a water soluble low-boiling-point polar solvent such as lower alcohol, ketone, ether, ethyl benzene, ethyl acetate, or the mixed solution of the above substances in any proportion, or the mixed solution of the above substance(s) with water in any proportion, fully dissolution and removal of butanol and other substances adsorbed inside the adsorbent (e.g. saturated adsorption resin) can be realized, and the desorbent can be recovered by distillation to be recycled; in addition, by elution of the residual desorbent inside the adsorbent with water, the processing of the residual desorbent in the resin can be realized, and therefore the adsorbent is regenerated.
(3) in the method for desorbing and regenerating a butanol-adsorbing hydrophobic macroporous polymer adsorbent of the present invention, the desorption and regeneration of the adsorbent (such as butanol-adsorbing resin) can be carried out directly in the butanol-adsorbing adsorption-desorption column without taking out the adsorbent from the adsorption-desorption column, saving a great deal of time and improving the regeneration efficiency.
(4) in the desorption and regeneration method of the present invention, the desorbed bed is eluted with water to recover the adsorption property of the resin, saving large quantities of solutions such as organic solvent, acid and base, with little pollution and low cost, and also saving a lot of time and improving the regeneration efficiency.
A water soluble low-boiling-point polar organic solvent is used to desorb butanol from the adsorbent more effectively, and a small amount of 2-3 bed volumes of water is used to regenerate the adsorbent, and according to the difference in affinities of the macroporous polymer adsorbent on the target substance of butanol and on the impurities such as acetone and ethanol, a hydrophobic macroporous polymer adsorbent with functional groups only adsorbing butanol but not adsorbing/adsorbing little acetone and ethanol is used to further achieve efficient separation of butanol from acetone and ethanol. Thus it can be seen that, the method of the present invention is novel and advantaged in simple process, short separation time, high recovery efficiency of butanol, easy, fast and complete desorption and regeneration, low investment in equipment and production costs, little pollution, reduced energy consumption, and is therefore easy for scale production with great promotion prospects. Experiments show that, with the method of the present invention, the yield of butanol can reach up to 99.8% and the adsorption capacity of the hydrophobic macroporous adsorption resin on butanol keeps basically unchanged through 30 cycles.
BRIEF DESCRIPTION OF THE DRAWINGS
Hereinafter, the embodiments of the present invention will be described in detail in combination with the accompanying drawings, wherein:
FIG. 1 shows results of adsorption capacities of various macroporous adsorption resins measured in Example 1 of the present invention.
FIG. 2 shows the adsorption-desorption apparatus used in the examples of the present invention.
FIG. 3 shows a GC chromatogram of supernatant in the broth after 48 hours of anaerobic fermentation with Clostridium acetobutylicum , wherein isobutanol is used as the internal standard.
FIG. 4 shows an outflow curve measured at the outlet of the resin column after butanol fermentation broth is adsorbed according to Example 2 of the present invention.
FIG. 5 shows a desorption curve measured at the outlet of the resin column during desorption of butanol adsorbed by the resin column according to Example 2 of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The present invention will be described with reference to specific examples. Those skilled in the art will appreciate that these examples are only intended to illustrate the present invention, rather than limit the scope of the present invention in any way.
The experimental methods in the following examples are all conventional methods unless expressly stated; and the experimental materials used in the examples were all purchased from conventional biochemical reagents store unless expressly stated. In the examples, the concentrations of the mixed solution (ABE) containing acetone, butanol and ethanol are detected by gas phase chromatography, and the instruments and conditions for measurement are as follows:
Agilent 7890 gas chromatography, HP-INNOWAX (19091N-236) capillary chromatography column (60 m×0.251 mm×0.50 μm).
Temperature programming: keeping at the initial temperature of 70° C. for 1 min, and then increasing the temperature to 190° C. at the rate of 20° C./min, and keeping at 190° C. for 2 min, with the total running time of 9 min.
Total flow is 100 mL/min, the flow rate of the carrier gas (N 2 ) is 90 mL/min; the column flow is 1 mL/min; the flow rate of H 2 is 30 mL/min; and the flow rate of air is 300 mL/min.
Temperature of the injection port is 180° C., temperature of FID detector is 220° C., injection volume is 1.0 μL, and split ratio is 90:1.
Quantitative analysis is performed by the internal standard method, and the internal standard is isobutanol.
In the following examples, the adsorption capacity of the macroporous adsorption resin is calculated according to the following formula:
q
e
=
(
C
0
-
C
e
)
V
W
wherein, C 0 represents the initial solubility (g/L) of butanol; C e represents the balanced solubility (g/L) of butanol; V represents the volume (L) of the butanol-containing solution; and W represents the mass (g) of the macroporous polymer adsorbent.
After adsorption equilibrium is reached, the residual adsorption solution is removed, and the saturated adsorption resin is desorbed by a water soluble low-boiling-point polar organic solvent, the desorption rate of the resin (i.e. desorption rate of butanol) is calculated according to the following formula:
D % =C x V 2 /( C 0 −C e ) V 1
wherein, C x represents the concentration (g/L) of butanol in the desorption solution after completion of desorption, V 2 represents the volume (L) of the desorption solution; and V 1 represents the total volume (L) of the absorption solution.
Example 1
In the present example, the adsorption capacities of different hydrophobic macroporous polymer adsorbents on acetone, butanol and ethanol in the mixed solution were measured, and the specific process was as follows.
A certain concentration of ABE mixed solution was prepared, wherein the concentration of butanol is 15 g/L, and the mass ratio of acetone, butanol and ethanol is 3:6:1, that is, the mass concentration of the three components in ABE is 3:6:1. 1 g macroporous polymer adsorbent (L 1-19 shown in FIG. 1 , which are respectively Amberlite series resins, Diaion series resins and D series resins) dried by suction was added into the above ABE mixed solution respectively, after saturated absorption is reached, the adsorption capacities and separation factors of the macroporous polymer adsorbents on ABE are calculated according to the GC method.
Results of separation factors are shown in Table 1.
TABLE 1
Model of resins
α ethanol butanol
α acetone butanol
L-1
2.31
1.59
L-2
0.89
35.6
L-3
0.95
1.67
L-4
8.33
14.56
L-5
0.20
0.42
L-6
7.22
110.83
L-7
2.73
1.17
L-8
2.10
4.80
L-9
2.68
0.72
L-10
1.89
66.19
L-11
1.89
13.54
L-12
0.76
0.62
L-13
1.75
33.57
L-14
5.19
3.49
L-15
943.51
297.93
L-16
2.02
12.79
L-17
124.18
4.03
L-18
2.66
3.09
L-19
165.48
52.25
The experimental results of adsorption capacities are shown in FIG. 1 . As can be seen from FIG. 1 , Diaion series resins (L-2, L-3, L-4, L-13, L-17) have relatively small adsorption capacity of butanol, and L-17 resin also adsorbs a small amount of byproducts such as acetone while adsorbing butanol; D series resins (L-1, L-5, L-6, L-7, L-8, L-9, L-10, L-11, L-12, L-14, L-16, L-18) have a slightly higher adsorption capacity of butanol, but they also absorb byproducts such as acetone and ethanol; Amberlite series resins (L-15, L-19) have a very high adsorption capacity of butanol, and they do not absorb byproducts such as acetone and ethanol. Wherein L-15 resin is a weak-polarity hydrophobic macroporous polymer adsorbent, which has a skeleton of styrene diethylbenzene and is an adsorption resin which has polar functional groups containing nitrogen, oxygen, sulfur, such as amide, cyano, phenolic hydroxyl group.
Methods for measuring various parameter of the resin are as follows:
The water content of the resin is measured according to the method disclosed in the literature (GB5757-86[S]); the content of active groups and apparent density (r a ) of the resin are measured by referring to the method disclosed in the literature (Binglin H E, Wenqiang Huang, Ion exchange and adsorption resin [M]. Shanghai: Shanghai Scientific and Technological Education Press, 1995); the specific surface area of the resin is measured by referring to the method disclosed in the literature (Qiming Tan, Zuoqing Shi, Measuring specific surface of porous resin with simple nitrogen adsorption method[J]. Ion Exchange and Adsorption, 1987, 3(1):30) through a simple BET instrument; the pore volume (V pore volume ) is calculated according to the formula V pore volume =1/r T ; and the average pore diameter is calculated according to the formula r=2V pore volume /S.
Example 2
In the present example, dynamic column adsorption was carried out using the L-15 macroporous adsorption resin (50 g) in Example 1, wherein the used butanol fermentation broth containing acetone, butanol and ethanol, was prepared as follows:
Anaerobic fermentation (nitrogen was bubbled into the fermentor before fermentation to maintain anaerobic environment, and the temperature was kept at 37° C.) was carried out using Clostridium acetobutylicum strain (provided by State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology) according to the conventional method in the art, and the fermentation broth was obtained after 48 hours, and then the supernatant (GC chromatogram is shown in FIG. 3 ) was obtained through centrifugation, the measurements show that the supernatant of the fermentation broth contains 4.56 g/L acetone, 11.91 g/L butanol, 1.40 g/L ethanol, 0.60 g/L butyric acid, 0.80 g/L acetic acid and 10.0 g/L glucose. The supernatant of this fermentation broth is used as the butanol fermentation broth for experiments in this and the following examples.
Dynamic adsorption of the supernatant of the butanol fermentation broth above was carried out by using the experiment apparatus shown in FIG. 2 , which specifically includes:
1) 1 L butanol fermentation broth containing acetone, butanol and ethanol was input into an adsorption-desorption column at a certain flow rate using a peristaltic pump. At the outlet of the column, samples were taken at regular time and the concentrations of acetone, butanol and ethanol were measured to obtain outflow curves (shown in FIG. 4 );
2) after 10 hours, the unabsorbed fermentation broth at the surface of the adsorbent or in the pore channels of the adsorbent was washed with no less than 1 times the amount of resin (V/V) and then water was emptied from the absorbed bed;
3) a certain volume of methanol was added as a desorbent, and infiltration was first carried out for 5 min, and then butanol in the resin phase was desorbed, samples were taken at regular time at the outlet of the column and the concentrations of the target substances were measured to obtain the desorption curves (shown in FIG. 5 );
4) finally, the desorbed bed was eluted with the regenerant (water) until there is no desorbent of methanol in the effluent, then the regeneration is completed, and the next stage of adsorption-desorption operation can be carried out.
It is proved through the above experiment that, L-15 resin can effectively adsorb butanol, and butanol can be effectively desorbed from L-15 resin with butanol adsorbed therein by using a water soluble low-boiling-point polar solvent of methanol.
Example 3
50 g L-15 resin was packed into a fixed bed, 1 L butanol fermentation broth (containing 4.56 g/L acetone, 11.91 g/L butanol, 1.40 g/L ethanol, 0.60 g/L butyric acid, 0.80 g/L acetic acid, 10.0 g/L glucose) was passed through the L-15 resin fixed bed at a flow rate of 1 BV/h, after 10 hours, measurements show that the volume of the remaining adsorption solution is 0.96 L, and the remaining adsorption solution contains 4.26 g/L acetone, 3.88 g/L butanol, 1.30 g/L ethanol, 0.56 g/L butyric acid, 0.72 g/L acetic acid and 9.6 g/L glucose.
The adsorption bed was washed with 2 BV water (until drying up), measurements show that the volume of the washing liquid is 0.2 L and the washing liquid contains 1.60 g/L acetone, 10.93 g/L butanol, 0.76 g/L ethanol, 0.312 g/L butyric acid, 0.294 g/L acetic acid and 3.92 g/L glucose. According to the mass conservation principle of each component, the saturated adsorption capacity of per gram of resin on each component calculated according to the following formula
q e = ( C 0 - C e ) V W
is: acetone 3 mg, butanol 120 mg, ethanol 0 mg, butyric acid 1 mg, acetic acid 0 mg, glucose 0 mg.
At 20° C., 1 BV methanol aqueous solution (85% V/V) was passed through the L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 0.6 BV/h to perform desorption. The volume of the elution effluent is 0.098 L, and the measurements show that the effluent contains 1.53 g/L acetone, 61.1 g/L butanol, 0.51 g/L butyric acid. Wherein the concentration of butanol in the eluent is 5.13 times the concentration of butanol in the fermentation broth.
The desorption rate of butanol is calculated to be 99.8% according to the formula
D % =C x V 2 /( C 0 −C e ) V 1 .
Methanol with low-boiling-point point was first distilled off by atmospheric rectification of the elution effluent, with recovery rate reaching 97.6%, and the resulting methanol can enter into the desorption liquid of next elution process; and then high concentration of butanol can be obtained by increasing temperature to above 120° C. under normal pressure or by reduced pressure distillation.
Example 4
At 20° C., 2 BV methanol aqueous solution (85% V/V) was passed through 50 g L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 1 BV/h.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 2 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.6 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.4%.
Example 5
At 20° C., 2 BV methanol aqueous solution (85% V/V) was passed through 50 g L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 0.8 BV/h to perform desorption of the resin.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 2 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.6 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.7%.
Example 6
At 40° C., 2 BV methanol aqueous solution (85% V/V) was passed through 50 g L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 1.2 BV/h to perform desorption of the resin.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 1 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.5 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.1%.
Example 7
At 30° C., 2 BV ethanol was passed through 50 g L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 0.8 BV/h to perform desorption of the resin.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 2 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.8 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.3%.
Example 8
At 30° C., 2 BV mixed solution of water, methanol and ethanol (water:methanol:ethanol=1:16:3 (volume ratio)) was passed through 50 g L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 1 BV/h to perform desorption of the resin.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 2 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.8 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.4%.
Example 9
At 30° C., 2 BV mixed solution of methanol and ethanol (methanol:ethanol=1:1 (volume ratio)) was passed through 50 g L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 1 BV/h to perform desorption of the resin.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 2 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.5 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.4%.
Example 10
At 30° C., 4 BV propanol was passed through 100 g L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 1.5 BV/h to perform desorption of the resin.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 2 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.6 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.2%.
Example 11
At 30° C., 2 BV ethyl acetate was passed through 50 g L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 0.8 BV/h to perform desorption of the resin.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 2 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.6 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.1%.
Example 12
At 30° C., 2 BV acetone was passed through 50 g L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 1 BV/h to perform desorption of the resin.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 2 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.6 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.1%.
Example 13
At 25° C., 3 BV ethyl ether was passed through 50 g L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 1.2 BV/h to perform desorption of the resin.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 2 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.6 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.0%.
Example 14
At 30° C., 2 BV ethyl benzene was passed through 50 g L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 0.8 BV/h to perform desorption of the resin.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 2 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.6 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.3%.
Example 15
50 g L-15 resin was made to adsorb butanol fermentation broth to achieve saturation using the adsorption-desorption apparatus shown in FIG. 2 according to the operation of Example 3, and the saturated adsorption capacity of the resin is 120 mg/g.
At 30° C., 2 BV methanol aqueous solution (85% V/V) was passed through the L-15 resin fixed bed with saturated adsorption of butanol fermentation broth at a flow rate of 1 BV/h to perform desorption of the resin.
When measurements show that there was no butanol in the desorption effluent, the remaining desorption solution was emptied from the bed, and 2 BV water was passed through the L-15 resin fixed bed at a flow rate of 0.6 BV/h.
According to the operation of Example 3, the amount of butanol in the desorption effluent was detected by GC, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.6%.
The above adsorption-desorption-regeneration operation was cycled 30 times using the adsorption-desorption apparatus (shown in FIG. 3 ), and the adsorption capacity and desorption rate of the resin were measured, and the measurements show that the adsorption capacity of L-15 resin on butanol is 120 mg/g, which keeps basically unchanged, and the desorption rate of each operation is higher than 99.3%.
Example 16
At 20° C., 3 BV methanol was successively passed through four fixed bed columns connected in series which were respectively filled with 50 g L-15 resin achieving saturated adsorption of butanol fermentation broth at a flow rate of 0.5 BV/h, to perform desorption of the resin, the effluent after the fourth column was collected and mixed, and then the amount of butanol in the desorption effluent was detected by GC according to the operation of Example 3, it is obtained through calculation that the desorption rate of butanol in the L-15 resin is 99.5%, and the concentration of butanol reaches 81.47 g/L, which is 6.84 times the concentration of butanol in the feed liquid.
When measurements show that there was no butanol in the desorption effluent from the fourth column, the remaining desorption solution was emptied from the bed, and 3 BV water was passed through four L-15 resin fixed bed columns connected in series at a flow rate of 0.6 BV/h to perform desorption of the resin.
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The present invention provides a method for desorbing and regenerating a butanol-adsorbing hydrophobic macroporous polymer adsorbent, comprising: successively eluting the hydrophobic macroporous polymer adsorbent with butanol adsorbed therein using a water soluble low-boiling-point polar solvent and water. The method provided in the present invention has a simple process, a short separation time, easy, fast and complete desorption and regeneration, low equipment investment and pollution, and reduced energy consumption, and therefore production is easy on a large scale.
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BACKGROUND OF THE INVENTION
The invention concerns a steering column switch with a housing, in which at least one operating lever is slewably and/or displaceably retained.
Steering column units of this type are customarily used in autmotive vehicles for operation or activation of light, window wiper, turn signal and similar.
The to be controlled functions, such as for example additional rear window wiper, interval circuits etc. depend upon type of vehicle and equipment. Since the consumer, for reasons of operating ease, cannot be expected to put up with idle switching positions, the steering column switching units had to be adapted to the respectively existing operating scope. This individual adjustment was done, for example, by means of exchange of contacts, flat pieces, etc. and thus required different construction of the major component of the steering column switching unit.
The present invention is therefore based on the object of creating a reasonably priced steering column switch unit, which comprises a multitude of functional- and application possibilities and, concurrently, offers high user convenience.
BRIEF SUMMARY OF THE INVENTION
The object is solved according to the invention by providing a steering column switch unit having a housing into which at least one operating lever is tiltably and/or displaceably retained. During assembly of the steering column switch unit, different operating lever types are installable with respective contact devices associated therewith. The housing in turn has a reverse contact device with a predefined maximum number of switching functions whereby the utilized selections of switching functions depends on the type of installable operating lever and their respective contact devices.
By means of the modular construction of a steering column switch unit, which, based upon application profile, differs only by differently mounted activation lever types, manufacturing costs can be significantly lowered as a result of the, except for the activation lever, constant design. However, in order to nevertheless cover all application possibilities, the steering column switch unit includes in the housing a reverse contact device, by means of which provision is made for all potential switching functions. The steering column switch unit installed in different vehicle types and, based upon equipment, thus only still differs in that it has different activation levers, which, depending upon type and equipment guaranty a consumer-friendly selection from the entire functional scope.
In a preferred embodiment of the invention, the mechanical operation of the lever path can also be adapted to the respective vehicle type. Thus, for example, the usual interaction between stop element and stop curve can be defined by means of added stops, which are located at the terminal region of the lever installed in the housing, the lever path [limited] along the stop curve to a pre-definable region, and also to a movement cross-wise to the stop curve. In this fashion, the operating lever can, for example, be made secure from any pull-out, from any movement towards or away from the operator by stops arranged at the different levers. Thus, in vehicles with less extensive functions, for example, without a rear window wiper, no undesirably long lever paths or idle positions are created.
Potentially lacking functions of the radial positions or positions of the operating lever, such as for example lacking interval circuit of a window wiper or lacking additional stages, can be compensated for, in a consumer-friendly manner, by limitation, to a given range of the stop curve, by at least one limit stop.
An otherwise identically designed steering column switch unit can be kept particularly variable if the stop curve at the lever end and the corresponding stop element is located in the housing in fixed manner. With this arrangement, the added possibility is afforded of limitation by stops, to change via simple exchange of an operating lever the entire stop curve characteristic. In such an arrangement, stop curve and stop element can also be located at the end of the lever whereby the entire bearing mechanism is designed at the end of the lever, and, after installation, one component, i.e. stop curve or stop element, is connected in fixed manner with the housing.
In a preferred embodiment of the invention, the operating lever has, preferably in its terminal region, an additional switching device. Said switching device, which consists, for example, of switches with two or more positions, potentiometers, etc. is connected via a connection line with a contact plug located at the installation end of the operating lever. Said contact plug can then be connected in the housing with a connection device, which fully comprises the maximum number of possible tie-ins. Thus, not only can operation levers with different switch devices be connected with the same tie-in device, but also operating levers with identical switch devices can be connected to different tie-ins of the connection device. A multitude of different functional possibilities can thus be beneficially realized.
The contact device and the corresponding reverse contact device, which serve for position registration of the operating lever, can be designed in the steering column switch unit according to the invention like customary electro-mechanical or electrical contacts. The state of the art provides for a multitude of realization possibilities like closing and opening of electrical contacts, conductor tracks, activation of switches and similar.
In the preferred embodiment of the invention, the contact device is designed as at least one magnet and the corresponding reverse contact device as at least one Hall-sensor. Said variation beneficially functions without mechanical friction, free from wear and tear.
In another embodiment of the invention, the steering column switch unit comprises in its housing an evaluation unit with pre-defined maximum operating range for transformation of signals, contacts and/or switch devices into control signals for corresponding vehicle functions. On this type of evaluation device, different signals can, for example, be linked with each other. It is also conceivable to house thereon the conversion of analog signals into control signals such as, for example, the Hall-sensor values or the resistance values of switches, rotary switches and potentiometers, for example for a window wiper motor.
For the realization of these electronic tasks, the evaluation unit may be hard-wired or constructed of programmable logic units, whereby the use of even a micro-processor with firmware is conceivable.
Selection of the complete functional range of the evaluation unit with respect to the invention can, in turn, be influenced by the respectively installed lever. The already described possibility of differing contact device, connection device as well as mechanical movement characteristic can hereby serve in selecting a certain total functional range of the evaluation unit. It is, however, also conceivable to also arrange at or in the lever an identification, which interacts as additional mechanical, electrical or electronic contact with a corresponding reverse contact in the housing and selects, in this manner, the functional scope of the evaluation unit. To that end, it is also conceivable to affix in or at the lever an electronic chip, similar to a phone card chip, which serves, via the connection device or an electronic scanning device for selecting the functional scope of the evaluation unit.
By the present invention, manufacturing costs of the except for the operating lever unchanging unit can be significantly lowered through mass production without limiting user comfort. Different operating levers can be beneficially employed by means of standardized mechanical and electrical connection devices during installation in the remaining part of the steering column switch unit. It is hereby even possible, by means of automatic recognition with respect as to which type of lever was installed, to precisely define the accurate function of the steering column switch unit during production of the levers.
Further specific embodiments of the invention become apparent from the sub-claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention is explained in more detail based on an embodiment represented in the drawing. The drawing depicts in
FIG. 1 a cross-section view of a steering column switch unit with installed operating lever;
FIG. 2 an exploded drawing in perspective view of an operating lever according to FIG. 1 before installation and
FIG. 3 an exploded drawing in perspective view of another specific embodiment of an operating lever.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Known steering column switch units customarily comprise two or three operating levers for different functions, such as for indicator lights and flasher lights, window wiper functions and, perhaps, illumination. The steering column switch unit 1, represented schematically in FIG. 1, comprises a housing 3, which concentrically envelops a steering post 5 of a motor vehicle. In the interior of the housing 3 is represented a head 7 of a single engaging operating lever 9, without going more specifically into further details of any other possibly existing operating levers. The following explanations regarding an operating lever 9 therefore apply with respect to such additional levers.
The operating lever, arranged cross-wise vis-a-vis the longitudinal axis of the steering column 5 is tiltably supported, via an axis 11, arranged paraxially relative to the longitudinal axis, in known, not more closely represented fashion, in housing 3 in a plane vertical vis-a-vis the longitudinal axis of the steering column 5. Three-dimensional bearing devices, employed for this purpose, which permit cross- and longitudinal tilting as well as out-pulling and in-pushing of the operating lever are well known in the state of the art and are represented here, since not essential to the invention, only schematically by means of bearing of axis 11.
Operating lever 9 has, at the frontal end of its head, a stop element 13, which is, in not more closely represented manner, stressed with a force in the direction of a stop curve 15, for example by means of a pressure spring arranged in head 7. Head 7 of the operating lever 9 has at a lateral wall, magnets 17 (for example 2) positioned vertically vis-a-vis axis 11. These magnets 17, as represented in FIG. 1, can be arranged at varying distances vis-a-vis axis 11, whereby, of course, magnets 17 may also be arranged next to each other at the same distance from axis 11, along the same circumferential line.
Opposite magnets 17, on the side wall of head 7, there are located in the interior of housing 3, Hall-sensors 21 on a flat piece 19, co-planar and at a distance to the side wall, so that a small space remains between the Hall-sensors 21 and the magnets 17. The Hall-sensors 19 have already been adjusted in number and position (in example three) to all contemplated operating lever types with varying movement characteristics and their differently positioned magnets 17. In the example schematically represented in FIG. 1 there are located on flat piece 19, at different radial distances vis-a-vis axis 11, three Hall-sensors 21, which may, however, in a plane vertical to the drawing plane, be arranged laterally staggered. Needless to say, several Hall-sensors 21 may also be arranged next to each other in this plane on the same circumferential line.
By providing a previously defined maximum number of Hall-sensor positions, it is possible to install different operating levers 9 for different functions without exchange of flat piece 19.
The movement characteristic of an operating lever 9 depends hereby upon the interaction between a stop curve 15 and a stop element 13, as well as upon possible mechanical stops. In such arrangement, one component of the interacting components is respectively arranged stationary in housing 3, and its complementary component at the head 7 of the operating lever 9.
In FIG. 1, shown schematically, the stop element 13 is for example, located at head 7 of the operating lever 9 and its complementary component, i.e. the concave stop curve 15, stationary in the interior of housing 3. Of course, the kinematic reverse is also possible, whereby the stop element 13 is then arranged in the interior of housing 3 and the stop curve 15 convex at the frontal side of head 7 of the operating lever 9 (embodiment according to FIG. 3).
FIG. 2 depicts in an exploded drawing the operating lever 9 as non-installed single component. The end of the operating lever 9 positioned opposite head 7 is designed as enlarged grip region 23, on which can be arranged activation elements. In FIG. 2 are arranged, for example, at the underside of the grip region 23, a push switch 25 and at the anterior side a toggle switch 27.
By operating the push switch 25, a contact 29 is closed and opened and by operating toggle switch 27, contacts 30 and 31 are closed and opened via a not represented mechanism. These contacts 29, 30, 31 are arranged, for that purpose, on a flat piece 33, located in the interior of grip region 23 of the operating lever 9.
The contacts 29, 30, 31 are electrically connected via a connection line 35, which extends inside the operating lever 9, with a plug 37, or its not represented contact pins.
During the installation of the steering column switch unit 1, said plug 37 is plugged into a connection device located on the flat piece 19 or connected with it. The connection device not shown in FIG. 1 can be designed, for example as universal coupling, whereby same already holds available all contacts for the most diverse lever types. The complementary plug 37 can then correspond in its exterior dimensions precisely to the interior dimensions of the connection device, so that installation-simplifying, standardized connection is guaranteed. In this case, the different operating lever types have plugs 37 of identical dimensions, whereby not all contact pins need then be occupied or present. It is, however, also conceivable to design the connection device in form of several connection couplings, whereby a different functional scope can be then chosen, depending upon into which connection coupling plug 37 is plugged in.
The operating lever 9, depicted in FIG. 3, points out the possibility of designing the head 7 of the operating lever 9 frontally as convex stop curve 15. Needless to say, as described above, the stop element 13 must then be arranged accordingly in the interior of housing 3. The stop curve 15 has two laterial walls 39, 40 which, in cooperation with the stop element 13 prevent any movement cross-wise vis-a-vis the radial movement along the stop curve 15. Such a lever with lateral walls 39, 40 serving as stop could, for example, find application as window wiper operating lever in vehicles without rear window wiper and avoid, in this manner, unwelcome mechanical idle positions. Furthermore, the under and upper side of head 7 of the operating lever 9, in cooperation with the for said purpose complementary components in or at housing 3, can serve as stop for limiting the lever path along the stop curve 15.
On the flat piece 19 (in FIG. 1), there may also be located, in unrepresented fashion, electronics, which not only transmits the individual contact conditions and Hall-sensor values, but also analyzes, interconnects and processes them. It is thus, for example, conceivable that switches arranged in grip region 23 transmit analog signals in form of varying resistance values, which must first be converted into control signals by means of electronic logic. The exact function selection of such evaluation unit, which basically makes available the maximum number of needed functions or signal processings, can, in turn, then be selected based upon employed lever type. It is, for example, conceivable to affix on the flat piece 35, within the operating lever 9, a circuit, which is in communication via connection line 35 with the electronics on the flat piece 19. In this manner, a certain lever type could be electronically recognized and, in addition, also influence the scope of function or the processing of signals for variation in contact seizure and mechanical movement characteristic.
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A steering column switch unit (1) includes a housing (3) in which at least one operating lever (9) is tiltably and/or displaceably retained, for which, during installation, different operating lever types with respective contact device are installable, whereby the steering column switch unit (1) in housing (3) has a reverse contact device with a pre-defined maximum number of switching functions, and whereby the employed choice of switching functions depends upon the type of the installable operating lever (9) and its contact device.
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BACKGROUND OF THE INVENTION
The invention relates to polyurethane molding compositions, such as polyurethane casting compositions, which are prepared by the polyaddition of diisocyanates to polyols or from prepolymers with appropriate end groups. More specifically, the invention relates to polyurethane molding compositions containing catalysts which aid such compositions in passing from the liquid to the solid state and in setting in economically justifiable times.
Polyurethane molding compositions, such as casting compositions, are utilized in medical technology, for example, in dialysis and diafiltration equipment for the treatment of blood and blood fluids. Since these blood and blood fluids are returned to the blood flow after dialysis or diafiltration, it is necessary that all components of casting compositions, which come into contact with the blood or blood fluids, are absolutely safe physiologically and completely nonpoisonous.
For this reason, polyurethane molding compositions, when used in medical applications, cannot be hardened with many well-known catalysts, since these catalysts either must be avoided for toxicological reasons and/or have other disadvantages. Accordingly, organic tin compounds and tertiary amines are not absolutely safe for toxicological reasons. Moreover, the tertiary amines also have the disadvantage that they lead to the formation of bubbles in many systems, especially if the work is not conducted with the complete exclusion of moisture.
Other well-known, especially salt-like catalysts, have only limited solubility in the polyol component and, being a solid substance, are not readily measured out. When dissolved in the diiscyonate component, they lead to undesirable side effects, and decomposition and resinification are observed on storage.
For toxicological reasons, acids, such as hydrochloric acid, acetic acid and trichloroacetic acid, also may not be used in medical technology, for example, when casting hollow-fiber or flat-film dialyzers.
For this reason, a catalyst-free polyurethane molding composition is suggested by German Offenlegungsschrift No. 2,340,661, so that this molding composition contains no toxicologically doubtful components. However, such casting compositions have a disadvantage in that they require a relatively long period of setting, that the setting must be carried out at comparatively high temperatures and that the catalyst-free setting can only be carried out with specific compositions of the molding material.
It is well known that certain physiologically absolutely safe carboxylic acids may be used as catalysts for polyurethane molding compositions. According to the U.S. Patent, oleic acid is used for this purpose, according to Chemical Abstracts, vol. 84, 1976, reference 61474p, octanoic acid is used, and according to the British Pat. No. 1,453,152, an alkyl or alkoxy-substituted benzoic acid is used. Such catalysts, however, give relatively long mold-release times, which lead to a decreased output per day.
Thus, polyurethane molding compositions and processes for making molding compositions which are not poisonous, which are physiologically absolutely safe, which do not give off any physiologically doubtful material on contact with blood or other body fluids, and which provide an accelerated mold-release time, i.e., to reach as quickly as possible a degree of hardness which will permit the molding to be taken from the mold without danger of deformation, are highly desirable.
SUMMARY OF THE INVENTION
It has now been found that these advantages can be provided by catalytically set polyurethane molding compositions containing as a catalyst setting agent a member from the group consisting of sorbic acid, parasorbic acid, cinnamic acid and mixtures thereof. These compositions can be prepared by the catalytic setting of polyurethane molding compositions, which contain diisocyanates and polyols and/or polyurethane prepolymers with isocyanate or hydroxyl groups, with at least one physiologically safe carboxylic acid selected from the group consisting of sorbic acid, parasorbic acid, and cinnamic acid.
In a preferred embodiment the catalytically set polyurethane molding compositions are prepared by reacting polyisocyanate with polyol in the presence of a setting agent selected from the group consisting of sorbic acid, parasorbic acid, cinnamic acid and mixtures thereof at a temperature and for a time sufficient to achieve a Shore A hardness of at least about 25.
In another preferred embodiment of the present invention, the carboxylic acid setting agent is used in mixture with a physiologically safe heavy metal containing catalyst.
The setting agent in the catalytically set polyurethane molding compositions of the present invention can comprise from about 0.1 to about 3.0 weight percent of said composition. Preferably, the setting agent comprises from about 0.4 to about 1.0 weight percent of the composition.
DETAILED DESCRIPTION OF THE INVENTION
The setting agents for the polyurethane molding compositions of the present invention include sorbic acid, i.e., 2,4-hexadienoic acid, parasorbic acid, cinnamic acid and mixtures thereof. These carboxylic acids are not poisonous, are odorless and do not form foam. By way of example, sorbic acid is used as a food additive. These carboxylic acids are also soluble in the polyol component, which simplifies their processing.
Setting with the help of sorbic acid or cinnamic acid can be carried out at room temperature, for example, at from about 18° to about 24° C., or at elevated temperatures, for example, between room temperature and 70° C.
The sorbic acid, parasorbic acid or cinnamic acid may either be used alone or together with heavy metal containing catalysts, provided that the mixtures of carboxylic acids with these heavy metal containing catalysts are physiologically safe. Suitable heavy metal containing catalyst include, for example, iron acetyl acetonate or di-N-octyl-di-(thioglycollic acid octyl ester). Surprisingly, there is a synergistic effect between the carboxylic acids and such heavy metal containing catalysts, in that the setting proceeds more rapidly than would have been expected by the additive effect of both components individually.
The term polyurethane prepolymer is used herein in the conventional sense. Such polyurethane prepolymers are usually prepared by the reaction of an excess of an organic diisocyanate of the general formula
OCN--B--NCO,
in which B is a divalent organic residue, with a polyether or polyester polyol with a molecular weight of 400 to 10,000, usually of 600 to 7,000 and preferably of 1,000 to 6,000, a prepolymer with --NCO end groups being obtained. The equivalent ratio of diisocyanate to polyol should be greater than 1 and, preferably, is large enough so that the polyurethane prepolymer melts below 80° C., and most preferably, so that the prepolymer is liquid at room temperature.
Suitable polyfunctional polyols for use in the preparation of the polyurethane prepolymers by reactions with a suitable isocyanate compound include polyalkylene ether glycols of the general formula
HO--(RX).sub.n --H
in which R represents the same or different alkylene residues with up to about 10 carbon atoms, X represents oxygen or sulfur and n is an integer such that the molecular weight of the polyakylene ether glycol is at least about 400 and, by way of example, lies somewhere in the range of 400 to about 10,000. Preferred polyalkylene ether glycols of this general formula include polyethylene glycols, polypropylene glycols, polybutylene glycols, polytetramethylene glycols, polyhexamethylene glycols and the like. These glycols can be obtained, for example, by the acid catalyzed condensation of the corresponding monomeric glycols or by the condensation of low molecular weight alkylene oxides, such as ethylene oxide, propylene oxide and the like, either with themselves or with glycols such as ethylene glycol, propylene glycol or the like.
Other suitable polyol reactants comprise polyalkylenearylene ether glycols, which also have high molecular weights in the range of about 400 to about 10,000. The polyalkylenearylene ether glycols differ from the above-described polyalkylene glycols in that they have arylene residues, such as phenyl residues or naphthyl residues, or optionally, substituted arylene residues such as, for example, arylene residues substituted by alkyl groups or aryl groups or the like, instead of some of the alkylene residues in the polyalkylene glycols. Polyalkylenearylene glycols of the type conventionally used for this purpose usually contain at least one alkylene ether residue with a molecular weight of about 500 for every aryl residue present.
Essentially linear polyesters, which contain several isocyanate reactive hydroxyl groups, represent another class of reactive, organic, polyfunctional polyols which may be employed in the preparation of the polyurethanes useful in the present invention. Although the state of the art of the preparation of polyesters suitable for this purpose has already been described in great detail and actually is not a part of the present invention, it is nevertheless mentioned here for the purpose of explanation that polyesters of this type can be produced by the combination of multivalent alcohols, generally a saturated aliphatic diol, with a polycarboxylic acid or anhydride thereof. Suitable multivalent alcohols comprise ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,3-hexanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol and the like. Mixtures of such diols can also be used with one another or with smaller amounts of polyols having more than two hydroxyl groups, preferably saturated aliphatic polyols, such as glycerol, trimethylol methane, trimethylol propane, pentaerithritol, sorbitol and the like. The polycarboxylic acids or anydrides thereof are generally dicarboxylic acids or their anhydrides. Preferably, the polycarboxylic acid or anhydride is either a saturated one or one which contains only benzenoid unsaturation, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, malic acid, azelaic acid, sebacic acid, phthalic acid, cyclohexane dicarboxylic acid and endomethylenetetrahydrophthalic acids and the like, as well as their isomers, homologs and other substituted derivatives, such as the chloro derivatives. Mixtures of such acids can also be either with themselves or with unsaturated carboxylic acids or anhydrides of the same, such as maleic acid, fumaric acid, citraconic acid, and itaconic acid or the like, as well as with the polycarboxylic acids with 3 or more carboxyl groups, such as aconitic acid and the like.
The essentially linear or branched polyesters, which are usually employed in the preparation of polyurethane resins, preferably have molecular weights in the range of about 750 to 3000. In addition, they generally have relatively low acid numbers, preferably below about 60 and most preferably, as low as can be obtained under practical conditions, for example, 2 or less. Correspondingly, they generally have relatively high hydroxyl numbers, preferably, from about 30 to about 700. In the preparation of these polyesters, an excess of polyol over polycarboxylic acid is generally used in order to ensure that the resultant, essentially linear polyester chains contain a sufficient number of reactive hydroxyl groups.
Still another class of suitable organic, polyfunctional polyol reactants includes polyalkylene ether polyols with more than two reactive hydroxyl groups, such as polyalkylene ether triols, tetrols and the like. Such polyfunctional polyols are prepared, for example, by the reaction of polyols, such as glycerol, trimethylol ethane, trimethylol propane, pentaerithritol, dipentaerithritol, sorbitol and the like with low molecular alkylene oxides, such as ethylene oxide, propylene oxide and the like.
Castor oils and polyols based on castor oils, obtained from castor oil by, for example, chemical modification (see Patton et al., Gummi, Asbest, Kunststoffe, 14 (1961), pages 918 ff.), also can be used as the polyol component in the present invention.
As can be seen from the above description, mixtures of the various reactive, polyfunctional polyols can also be employed in the preparation of polyurethane prepolymers useful in the present invention.
The polyester polyols or polyether polyols, which were described above, can be combined with a slight excess of anyone of a large number of polyisocyanates in order to form a polyurethane prepolymer. As stated above, the polyisocyanate can conveniently be expressed by the formula
OCN--B--NCO
in which B represents a divalent organic residue and may be aliphatic, aromatic or aliphatic-aromatic in nature. Accordingly, the divalent or double-bonding residue B may be a phenyl residue, which is unsubstituted or substituted by chlorine atoms, nitro groups, low molecular alkoxy groups, low molecular alkyl groups, phenoxy groups or phenyl residues; a diphenylene residue which can be unsubstituted or substituted by low molecular weight alkyl groups or low molecular weight alkoxy groups; a bisphenylene lower alkylene residue, which may be unsubstituted or substituted by low molecular weight alkoxy groups; a halogenated alkyl residue with 2 to 8 carbon atoms, which may be unsubstituted or substituted by low molecular weight alkoxy groups; a cycloalkylene residue with 4 to 8 carbon atoms, which may be unsubstituted or substituted by low molecular weight alkyl groups; or a bis-cyclohexylene lower alkyl residue.
Divalent organic residues B may be substituted by various substituents, such as, for example, by low molecular weight alkoxy groups, by low molecular weight alkyl groups, phenyl residues or phenoxy residues. Representative polyisocyanates are, for example: 1-methoxyphenyl-2,4-diisocyanate, 1-methyl-4-methoxyphenyl-2,5-diisocyanate, 1-ethoxyphenyl-2,4-diisocyanate, 1,3-dimethoxyphenyl-4,6-diisocyanate, 1,4-dimethylphenyl-2,5-diisocyanate, 1-propoxyphenyl-2,4-diisocyanate, 1-isobutoxyphenyl-2,4-diisocyanate, 1,4-diethoxyphenyl-2,5-diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, diphenylether-2,4-diisocyanate, naphthalene-1,4-diisocyanate, 1,1'-dinaphthalene-2,2-diisocyanate, biphenyl-2,4-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, diphenyl-methane-2,2'-diisocyanate, 3,3'-dimethoxydiphenylmethane-4,4'-diisocyanate, benzophenone-3,3'-diisocyanate, ethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, pentylene diisocyanate, methylbutylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dipropyl diisocyanate ether, heptamethylene diisocyanate, 2,2-dimethylpentylene diisocyanate, 3-methoxy-hexamethylene-diisocyanate, octamethylene diisocyanate, 2,2,4-trimethylpentylene diisocyanate, 3-butoxyhexamethylene diisocyanate, 1,3-dimethylbenzene diisocyanate, 1,4-dimethylbenzene diisocyanate, 1,2-dimethyl cyclohexane diisocyanate, 1,4-dimethylcyclohexane diisocyanate, 1,4-diethylbenzene diisocyanate, 1,4-dimethylnaphthalene diisocyanate, 1,5-dimethylnaphthalene diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 1-methylcyclohexane-2,4-diisocyanate, 1-methylcyclohexane-2,5-diisocyanate, 1-ethylcyclohexane-2,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethylmethane-4,4'-diisocyanate, dicyclohexyldimethylmethane-4,4'-diisocyanate, 2,2-dimethyldicyclohexylmethane-4,4'-diisocyanate, 3,3', 5,5'-tetramethyldicyclohexylmethane-4,4'-diisocyanate, 4,4'-methylene-bis-cyclohexyl isocyanate, ethylidine diisocyanate, 1,2-propylene diisocyanate, 4,4'-diphenyl diisocyanate, dianisidine diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenyl ether diisocyanate, m- and p-phenylene diisocyanate, 4,4'-toluidine diisocyanate, isopropylene-bis-(phenyl or cyclohexyl isocyanate), 1,3-cyclopentylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, chlorodiphenyl diisocyanate, 4,4',4"-triphenylmethane triisocyanate, 1,3,5-benzene triisocyanate or phenylethylene diisocyanate.
The amounts of setting catalysts used in the present invention can vary from about 0.1 to about 3.0 percent by weight, and preferably from about 0.4 to about 1.0 percent by weight of the molding composition. The time needed to obtain a hardened mixture having a "Shore A hardness" of between 20 to 30, which can be removed from the mold, varies depending upon the temperature of setting, the catalyst concentration, and the amount and type of the polyurethane system. The temperature for setting the composition can vary from ambient temperatures to elevated temperatures of about 40° C. or up to 70° C. For small amounts between 10 and 50 g., the setting time lies between a few minutes and 2 hours, for example, between 15 and 30 minutes. At room temperature, the final hardness of these castings is reached at times between several hours and several days.
The composition and process of the present invention can be used for the production of objects usable in medical science, for example, for casing and connecting the various parts of dialysis and diafiltration equipment. Since the hardness required for mold release is reached relatively rapidly, a high production output can be achieved with the present composition and process.
The following examples are presented for the purposes of illustrating, but not limiting, the process of the present invention.
EXAMPLE
A catalyst-containing polyol component (64 parts), consisting of 90 percent castor oil, 10 percent polyether (molecular weight 2600) and 0.5 percent of the acid to be tested, were mixed with 36 parts of diphenylmethane-4,4'-diisocyanate polyether prepolymer. The mixture was degassed under vacuum. Samples of this mixture (40 g) were poured into paper cups and hardened at 40° C. At this temperature, the Shore A hardness was measured after 30 minutes. A Shore A hardness was regarded as critical for the mold release. This procedure was carried out with sorbic acid, cinnamic acid, oleic acid, octanoic acid, 2-methoxy benzoic acid, o-tolyl acid, m-tolyl acid and p-tolyl acid, respectively. The results are set forth below in the Table.
TABLE______________________________________ Shore A. HardnessCatalyst after 30 minutes______________________________________sorbic acid 27cinnamic acid 25oleic acid not measurableoctanoic acid 152-methoxybenzoic acid not measurableo-tolyl acid 22m-tolyl acid 20p-tolyl acid 15______________________________________
The values in the Table show that only sorbic acid and cinnamic acid have reached the value of 25 after 30 minutes, which is critical for mold release.
Heavy foam formation was observed in the case of octanoic acid and oleic acid. This also explains the low final hardness. There was hardly any bubble formation with sorbic acid or o-tolyl acid.
It will be understood that the embodiments described above are merely exemplary and that persons skilled in the art may make many variations and modifications without department from the spirit and scope of the invention. All such modifications and variations are intended to be included within the scope of the invention as defined by the appended claims.
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Polyurethane molding compositions are disclosed which contain diisocyanates and polyols and/or polyurethane prepolymers and sorbic acid or cinnamic as a setting catalyst. A process for preparing such compositions is also disclosed. These compositions give a rapid initial hardening and therefore mold release properties, which contribute to increased production speeds. Moreover, the acids used are physiologically safe, so that the process may be used for the production of objects used in medical science. The acids may also be used in a physiologically safe mixture with a heavy-metal containing catalyst.
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This application is the U.S. national phase of International Application No. PCT/GB2007/050443, filed 26 Jul. 2007, which designated the U.S. and claims priority to Great Britain Application No. 0615389.4, filed 3 Aug. 2006, the entire contents of each of which are hereby incorporated by reference.
FIELD
This invention is concerned with alleviating the need for high power transmit/receive modules in phased array antennas and therefore reducing the cost of such array antennas.
BACKGROUND
The general trend in the art, when constructing phased array antennas, is to determine the highest operating frequency of an antenna to be constructed and, based on the requirements for spacing the radiating elements that result from this selected operating frequency, placing radiating elements coupled to transmit/receive modules at exactly this spacing to minimise the number of transmit/receive modules used. However, to obtain high-powered phased array antennas using this methodology, the skilled person is inclined to utilise the highest powered transmit/receive modules available. However, this is not a very cost-effective method of constructing a phased array antenna, as high power transmit/receive modules are usually very expensive.
SUMMARY
Accordingly, the present invention provides a phased array antenna comprising: a plurality of communication modules; wherein a power density of said phased array antenna is equivalent to a power density of a second antenna that has fewer, higher power communication modules than the said phased array antenna.
Preferably, each antenna element is connected to a communication module implemented as a highly integrated unit using a very small number, ideally one or two, integrated circuits.
The communication module is preferably a transmit and/or receive module.
The advantage of the present invention is that, by increasing the number of transmit/receive modules at the same time as increasing their density over the array face, less powerful modules can be used, which significantly reduces the cost of the array in total as each module becomes significantly simpler and cheaper, and the same or comparable power can be maintained per unit area of the array face.
DESCRIPTION OF THE DRAWING
Specific embodiments of the invention will now be described, by way of example only and with reference to the accompanying drawings that have like reference numerals, wherein:
FIG. 1 is a schematic showing the basic structure of the array antenna;
FIG. 2 is a diagram illustrating an exemplary structure of an array antenna face;
FIG. 3 is a diagram illustrating another example of a structure of an array antenna face;
FIG. 4 is a diagram showing the configuration behind the elements of the array face; and
FIG. 5 is a diagram illustrating a possible two-chip transmit/receive module for use with an array antenna.
A specific embodiment of the present invention is shown in FIGS. 1 to 5 and will now be described with reference to these Figures in more detail below.
DETAILED DESCRIPTION
FIG. 1 is a schematic diagram of an antenna apparatus according to the specific embodiment of the present invention. The antenna apparatus 100 has a processing portion 200 in communication (as shown by arrow 20 ) with an array portion 300 . Processing portion 200 is, in turn, in communication (as shown by arrow 10 ) with an external system (not shown). Further, the array portion 300 has an array face 400 that is shown in FIGS. 2 . and 3 and described in more detail below with reference to these figures.
FIG. 2 shows the array face 400 of the specific embodiment of the invention. The array face 400 is made up of a grid of radiating elements 410 , spaced equally with a width D 1 between each radiating element 410 in the horizontal direction and a width D 2 between each radiating element 410 in the vertical direction. This arrangement is facilitated by providing each row of the radiating elements 410 along linear structures 420 a to 420 f . The linear structures 420 a to 420 f are stacked so that each row of radiating elements 410 are in parallel with one another. Width D 1 may be equal to, or different from, width D 2 .
FIG. 3 shows an array face 400 ′ according to an alternative embodiment of the invention. The array face 400 is made up of an offset grid of radiating elements 410 . Here, the radiating elements 410 are spaced equally with a width D 1 between each radiating element 410 in the horizontal direction. The difference from the specific embodiment shown in FIG. 2 is that, while there is a width D 2 between each row of radiating elements 410 in the vertical direction, adjacent rows of radiating elements are not aligned in the vertical direction. The arrangement is facilitated by providing each row of the radiating elements 410 along linear structures 420 a′ and 420 f′ which are stacked in parallel to one another but offset in the horizontal direction by half of width D 1 such that every other linear structure 420 a′ , 420 c′ , 420 e′ , and 420 b′ , 420 d′ of radiating elements 410 are aligned in the vertical direction. As with the specific embodiment shown in FIG. 2 , the width D 1 may be equal to, or different from, width D 2 .
In further alternative embodiments, as the offset of half of width D 1 between linear structures is an arbitrary choice, the skilled person would understand that many different offset arrangements could be used to implement the present invention.
Referring now to FIG. 4 , which shows the configuration of the array antenna 100 behind the array face 400 on which the radiating elements 410 are located. This shows that each radiating element 410 , 410 ′, 410 ″ is in communication with a transmit/receive module 500 , 500 ′, 500 ″ (as shown by arrows 34 , 34 ′, 34 ″) which is in turn in communication with combining element 450 (as shown by arrows 32 , 32 ′, 32 ″). Each combining element 450 is in turn in communication (as shown by arrow 36 ) with the main array portion 300 . A plurality of transmit/receive modules 500 may be in communication with one combining element 450 . Alternatively more than one combining element is then combined.
In the specific embodiment, with reference to FIG. 5 , the transmit/receive module 500 takes the form of a two-chip solution. The transmit/receive module 500 comprises a Radio Frequency (RF) chip 510 , preferably implemented in Gallium Arsenide or Gallium Nitride, connected by wire bonds 540 to Silicon chip 520 . The chips 510 , 520 are separated from each other by a ceramic shelf 530 . The Gallium-Arsenide chip 510 is responsible for the radio frequency amplification, power generation and phase control while the Silicon chip 520 is responsible for any necessary digital control and housekeeping functions. In this arrangement, the RF chip 510 is mounted on a base plate (not shown) to dissipate any heat generated. An advantage of this solution is that each chip is suited to its application, whereas a single chip solution would compromise performance in either the digital control (if a Gallium-Arsenide chip) or radio frequency gain, amplification, power generation and phase control (if a Silicon chip).
Any solution a skilled person appreciates is relatively easy to manufacture can be used as an alternative to the above two-chip solution of the specific embodiment of the invention. For example, a one-chip solution may be preferred by the skilled person.
The method of configuring the layout of radiating elements on 410 on the array face 400 is determined by, firstly, the required power from the array antenna, and secondly, the required power per unit area that is required to accomplish this.
The required spacing D of the radiating elements 410 can therefore be determined from this calculation, in order to give the appropriate power per unit area needed by the antenna.
Using the determined value for the required power per unit area and required spacing D of the radiating elements, and with knowledge of the power of each transmit/receive module to be used, a suitable density of transmit/receive modules can be determined.
The skilled person will appreciate that, by not using a low density of very high power transmit/receive modules, which are each very expensive, and instead using a higher density of low to medium power transmit/receive modules, which are comparably much cheaper, the overall cost of the antenna can be reduced without compromising the power rating of the antenna as a whole.
A skilled person will also appreciate that the above is only possible with physically compact transmit/receive modules and radiating elements, which is provided in the two-chip solution suggested above. The design of a suitable compact radiating element is the subject of GB patent application no. 0523818.3 entitled “Antennas”.
The skilled person would readily appreciate that the above embodiment can be altered without departing from the scope of the planned invention defined by the claims. For instance, various radiating elements, transmit/receive modules and array phased configurations can be utilised whilst falling within the scope of the present invention.
Further, the array may be configured such that the radiating elements 410 are based on linear structures that are aligned vertically or in any other suitable arrangement.
The skilled person will appreciate that the dimensions of spacing D between each radiating element are not necessarily the same in both the vertical and horizontal dimensions.
Further, the skilled person would also appreciate that the exact construction of the radiating elements connections to the transmit/receive modules can be altered whilst still utilising the solution of the present invention, which is to reduce the cost of the transmit/receive modules such that it is possible to utilise a larger concentration of these modules to achieve the same overall power per unit area of an array antenna.
An important aspect of the present invention is that the cost reductions achievable by the use of highly integrated, low power transmit/receive modules (even in the larger numbers required) are significant compared to conventional techniques based on smaller numbers of high power modules, due principally to the disproportionately high cost of high power modules.
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This invention relates to utilizing a larger number of lower power transmit/receive modules in a phased antenna array in order to utilize cheaper and simpler transmit/receive modules whilst retaining comparable power per unit area as can be achieved through using conventional high powered transmit/receive modules. The advantage of this arrangement is that cheaper antenna arrays can be constructed without limiting the capability and/or performance of a system incorporating such an array when compared to a conventional solution.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention concerns a wind-power system with a tower built from several tower segments, with a generator for generating power arranged in the region of the tower head, with a power module, and with current-carrying means for carrying the generated current from the tower head.
[0003] 2. Description of the Related Art
[0004] In known wind-power systems, the electrical power module of a wind-power system, which includes electrical units, such as transformers, service cabinets, optionally, rectifiers, medium-voltage networks, low-voltage distribution devices, etc., is arranged underneath the level of the generator and frequently in the region of the tower base of the wind-power system. For all or some of these components, usually a small, separate building is provided outside of the wind-power system.
[0005] In order to transmit the electrical energy generated by the generator, which is arranged within a gondola in the region of the top of the tower, to the power module, there are current-carrying means, which run for the most part within the tower and which are embodied in the form of cables. These cables are mounted in the tower after it has been erected. This is a costly process, because the cables must be installed in a separate procedure over the entire height of the tower. Furthermore, this procedure is dependent on the tower already being erected.
[0006] However, it is not absolutely necessary to arrange the power module completely in the region of the tower base. In principle, other positions are also conceivable. The current-carrying means therefore must essentially fulfill the purpose of carrying the current generated and possibly preprocessed in the region of the tower head away from the tower head.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention provides a wind-power system, which can be erected more easily and thus also more economically and more quickly, and in which the power module is not absolutely necessarily in the region of the tower base.
[0008] According to the invention, the current-carrying means are premounted in a segmented way into the tower segments and in that the power module is arranged at least partially in the region of the tower head and/or at a distance from the tower base.
[0009] The segments of the current-carrying means are thus prefabricated and preferably attached to the tower segments before the tower is erected from the individual tower segments. Thus, it is no longer necessary to draw cables through the tower in a complicated process after erecting the tower. Due to the means according to the invention, the total erection time of the wind-power system can be shortened and the costs for the erection reduced, without having to take into account any technical disadvantages.
[0010] To avoid arranging a power module in the region of the tower base, it is also proposed that the power module be arranged at least partially in the region of the tower head and/or at a distance from the tower base. Preferably, the power module is mounted—partially or completely—within or outside the gondola. In contrast, in off-shore wind-power systems, preferably the power module is arranged—partially or completely—on land, for example, in the closest area of solid ground or on a nearby island and to connect the wind-power system to the power module through underwater cables.
[0011] In another preferred configuration, the power module has at least two power module units, one of which is arranged in the region of the tower head and the other underneath the tower head, thus in the region of the tower base or at a distance from the tower base. The current-carrying means are then provided essentially to connect the two power module units.
[0012] Additional advantageous configurations of the wind-power system according to the invention are given in the subordinate claims. Preferably, the segments of the current-carrying means are rigidly connected in the assembled state to the associated tower segment only in one region, preferably in the uppermost region. This attachment to the tower segment is realized preferably before the tower is erected, so that the tower segments, including the attached segments of the current-carrying means, are prefabricated. Because the segment of the current-carrying means is attached rigidly to the tower only at one point, it is suspended tightly but does move within certain limits on the inner wall of the tower segment and thus can also be aligned in order to form as good and easy a connection as possible to the next segments of the current-carrying means of the next tower segment.
[0013] For additional attachment of the segments of the current-carrying means within the tower segment, additional holding elements can also be provided on the inner wall of the tower, with which the segments of the current-carrying means are rigidly connected before or after the tower is erected in order to fix these as well as possible.
[0014] If the current-carrying means are formed as cables, for bypassing flanges or parts projecting from the tower inner wall, the lengths of the cable sections can be dimensioned in the tower segments so that bypassing these areas is possible without a problem.
[0015] For the use of busbars as current-carrying means, preferably flexible connecting bars are provided for bypassing parts projecting from the inner wall of the tower and/or for connecting busbar segments. These are used after the tower is erected to connect the busbar segments, if these do not reach each other directly or if gaps or other obstacles between the busbar segments, for example, a flange on the tower bar segment, must be bypassed.
[0016] In order, on the one hand, to protect service personnel from contacting the busbars when climbing through the interior of the tower and to guarantee electrical insulation and, on the other hand, to protect the current-carrying means from damage, in another configuration, a protective sleeve, especially a protective sheet, is provided, which is rigidly connected, for example, to the inner wall of the tower and protects the current-carrying means completely from touch. This protective sleeve can also be split into individual segments, which are premounted to the tower segments just like the segments of the current-carrying means. This configuration further shortens the time and simplifies the construction of the wind-power system.
[0017] The invention also concerns a tower segment for a tower of a wind-power system, which is built from several tower segments and which has a generator for generating power in the region of the tower head. The tower segment is characterized in that a current-carrying means segment for carrying the generated current from the tower head is premounted in the segment.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0018] The invention is explained in more detail below with reference to the drawings.
[0019] Shown are:
[0020] FIG. 1 , a representation of a wind-power system,
[0021] FIG. 2 , a section of such a wind-power system with two tower segments,
[0022] FIG. 3 , a perspective representation of busbars provided according to the invention,
[0023] FIG. 4 , a representation of a first wind-power system according to the invention,
[0024] FIG. 5 , a representation of a second wind-power system according to the invention, and
[0025] FIG. 6 , a representation of a third wind-power system according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The wind-power system 1 shown schematically in FIG. 1 and described in German Pat. No. 10 152 557 has a tower 2 with a foundation 3 , a gondola 4 supported so that it can rotate in the region of the top of the tower, as well as a power module 7 arranged in the region of the tower base, for example, in a small, separate housing. Within the gondola 4 , there is a rotor supported so that it can rotate about a horizontal axis with several rotor blades 5 , as well as an electrical generator 6 . The rotor is set in rotation by the force of wind acting on the rotor blades 5 and drives the generator 6 for generating electrical power.
[0027] For transmitting the energy generated by the generator 6 to the power module 7 , which has numerous electrical units, such as a transformer or optionally a rectifier for further processing of the electrical power before it is fed into the power network or transmitted to a load, according to the invention, there are busbars, preferably two busbars, attached to the wall by means of attachment elements 10 in the interior 8 of the tower 2 . These are electrically conductive and connected electrically to the power module 7 by means of a cable 11 to the generator, as well as by means of a connecting line 12 , which preferably leads through the foundation 3 and the subsoil.
[0028] The busbars 9 are rigid and preferably comprise individual busbar segments, as shown in more detail, for example, in FIG. 2 . There, two tower segments 21 , 22 are shown, from which the tower 2 is preferably built. Such tower segments 21 , 22 can be composed of, for example, steel or also concrete.
[0029] These tower segments 21 , 22 are prefabricated and joined to the tower at the site of the wind-power system. In order to shorten the erection time even more and to simplify the work and thus also to reduce the costs of the entire wind-power system, preferably the busbar segments 91 , 92 are rigidly attached to the corresponding locations of the individual tower segments 21 , 22 just before the tower 2 is erected. Preferably, the attachment of the busbar segments 91 , 92 is realized only in the upper region of the associated tower segment 21 , 22 by means of an attachment device 10 , while the remaining part of the busbar segments 91 , 92 is still movable within certain limits in order to simplify the connection to subsequent busbar segments. Through this construction, relative movements between the tower 2 and the busbars 91 , 92 , e.g., due to different expansion coefficients, can also be equalized. However, it can also be provided that additional holding elements 14 are used, which guide the busbar segments 91 , 92 over their entire length. For this purpose, the cross section of the opening for the busbar segments 91 , 92 can be dimensioned larger in the holding elements 14 than the cross section of the busbar segments 91 , 92 themselves. In this way, a relative movement of the busbar segments 91 , 92 into the holding elements 14 is enabled and simultaneously, the busbars 91 , 92 are guided and limited in their movements.
[0030] In order to connect the busbar segments 91 , 92 electrically and to bypass optional parts projecting into the interior, for example, flanges 211 , 212 at the lower and upper edge of the tower segments 21 , 22 , and insulated, flexible connecting bars 13 are used, whose shape can be changed by hand when attaching to the two busbar segments 91 , 92 . These connecting bars 13 can compensate for material expansions or contractions, e.g., due to temperature fluctuations.
[0031] In FIG. 3 , a perspective illustration of two parallel busbar segments 911 , 912 is shown. These are screwed tightly to the holding device 14 by means of screws 15 . Here, insulation means can be provided in order to insulate the busbar segments 911 , 912 from the holding devices 14 . Alternatively, the holding devices 14 themselves can also, of course, be produced from an insulating material. The holding device 14 itself is screwed tightly to the inner wall of the tower segment.
[0032] To protect the busbars 911 , 912 from contact when the wind-power system is in operation, a protective sheet 16 is also provided, which can be installed already in the individual tower segments just like the busbar segments 911 , 912 before the tower 2 is erected. By means of a guide bar 17 , which can be composed of, for example, a rigid rubber, on the one hand this protective sleeve is fixed and on the other hand it is insulated from the tower segment. However, for attaching the protective sheet 16 , other means, which are not shown here, can also be provided.
[0033] Furthermore, other devices, such as outlets, lights, etc., can also be attached in and/or on these protective sheets 16 provided as protective sleeves, so that these can be premounted also in a simple way. In addition, building these devices into the protective sleeve 16 prevents exposed mounting on the tower inner wall and thus leads to reduced risk of damage, e.g., due to falling objects when the tower is being erected and after it has been erected.
[0034] FIG. 4 shows a first configuration of a wind-power system according to the invention. Here, the power module 7 is preferably arranged within the gondola 4 and connected directly to the generator 6 by means of cables 18 . After the generated power has been processed in the power module 7 , it is led via another cable 19 to the busbars 9 , there guided through the tower to the tower base, from where it is discharged outwards via a connecting line 12 , for example, to a substation 40 , which can lie close to or far removed from the wind-power system. An alternative position of the power module 7 ′, indicated by dashed lines, can also be attached to the gondola 4 on the outside. Connecting cables from the generator 6 to the power module 7 ′, as well as from there to the busbars 9 , are left out for reasons of clarity.
[0035] FIG. 5 shows another configuration of a wind-power system according to the invention. Here, the power module comprises at least two power module units 71 , 72 . The first power module unit 71 is in turn arranged within the gondola 4 and performs initial processing of the generated power, for example, initial conversion to a different voltage range. Further processing of the generated power is then performed in the second power module unit 72 , which is arranged underneath the tower head, for example, as shown in the region of the tower base. However, the second power module unit 72 can also be arranged vertically underneath the tower 2 on the foundation 3 or far removed from the tower base. Likewise, naturally the first power module unit 71 can also be arranged outside on the gondola 4 , as shown in FIG. 4 .
[0036] FIG. 6 shows a configuration of a wind-power system according to the invention, which is formed as a so-called off-shore wind-power system. Here, this wind-power system 1 stands on another foundation 3 ′ anchored on the sea floor 25 . Indeed, in such off-shore wind-power systems, the power module can also be arranged in the region of the tower head or within the tower in the region of the tower base. However, preferably the power module 7 is arranged on land 30 and the power discharged from the tower head by means of the busbars. 9 is transmitted via underwater cables 12 ′ to the power module 7 . This has the advantage that the power module 7 does not require extra protection from negative effects of seawater and that maintenance on the power module 7 is significantly simpler.
[0037] All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety.
[0038] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
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The invention concerns a wind-power system for generating alternating current with a tower built from several tower segments, with a generator arranged in the region of the tower head, with a power module, and with current-carrying means for carrying the generated power from the tower head. In order to enable quicker, simpler, and thus more economical construction of the wind-power system, according to the invention, the current-carrying means are premounted in a segmented way in the tower segments and the power module is arranged at least partially in the region of the tower head and/or removed from the tower base.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation application of application Ser. No. 10/616,984, filed on Jul. 11, 2003, now abandoned the contents of which are hereby incorporated by reference in their entirety for all purposes.
FIELD OF THE INVENTION
This invention relates to golf club heads for golf clubs such as drivers, irons and putters.
BACKGROUND OF THE INVENTION
Many proposals have been made to design golf clubs which provide improved control over, and feel for, the golf ball, for example by providing grooves on the impact face of the golf club head. Reference may be made, for example, to U.S. Pat. Nos. 1,383,654, 1,452,695, 1,494,494, 5,176,384, 5,358,249, 5,405,136, 5,542,675, 5,766,093, 5,807,190 and 6,007,435. The disclosure of each of those patents is incorporated herein by reference for all purposes. Not all of the proposals comply with the USGA Rules of Golf, Rule 4 and Appendix II, which require that, for clubs other than putters, “the whole of the impact area” of the club face “must be of the same material” and that impact area markings, such as grooves, should comply with certain requirements. The “impact area” of a club head is referred to herein as the “impact face”.
SUMMARY OF THE INVENTION
In a first preferred aspect, this invention provides golf club head comprising
(1) a club head body, and
(2) a faceplate which
(i) provides an impact face and (ii) comprises a plurality of bars which can be individually deflected, without permanent damage, in a direction perpendicular to the impact face when the impact face strikes a golf ball.
In a second preferred aspect, this invention provides a method of making a golf club head, for example a golf club head according to the first preferred aspect of the invention, the method comprising
(A) providing a club head body; and
(B) forming an impact face on the club head body, the impact face comprising, after step (B), a plurality of bars which can be individually deflected, without permanent damage, in a direction perpendicular to the impact face when the impact face strikes a golf ball.
The composition, dimensions and arrangement of the bars are preferably chosen so that the impact face has a desired response when a golf ball impacts it at different positions across the insert. In some embodiments, the sidewalls of the bars are pre-shaped so that adjacent sidewalls provide grooves of desired dimensions on the impact face. For example, half grooves are machined onto the appropriate sidewalls so that, when the bars are incorporated into the faceplate, the adjacent half grooves form grooves on the impact face. This allows individual bars to be economically mass produced before being incorporated into an inset in the face of a club head. In some embodiments, the bars are retained in the recess by a dovetail geometry on the ends of the bars. In a preferred embodiment, a top and/or bottom retainer element is pressed into place in the dovetail in order to lock the bars into position.
Preferred club heads of the invention can provide important advantages by comparison with conventional golf clubs in which the impact face is provided by a single piece of material (and, therefore, has a “trampoline” geometry with a centroidal sweet spot outside of which performance drops off quickly). Such advantages can include:
a more desirable feel and larger “sweet spot” which results in improved uniformity of response upon impact for off-center hits and a reduction in the effect of off-center hits on the path of the struck ball, and a desired balance between maximized distance and control.
Preferred club heads of the invention, particularly club heads for irons and drivers, conform with the USGA Rules of Golf with respect to grooves on, and uniformity of material of, the impact face.
Preferred embodiments of the method of the invention provide an improved method of manufacturing a club head having grooves in its impact face.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically an exploded view of a golf club head incorporating a plurality of bars in accordance with the invention.
FIG. 2 shows a detail section view of the edge of the recess of FIG. 1 at area II including a dovetail mating surface.
FIG. 3 shows a detail view of two adjacent bars in cross section.
FIG. 4 shows an exemplary embodiment of an assembled “bars” iron.
FIG. 5 shows a cross-section through the line V-V of FIG. 4 .
FIG. 6 shows a cross-section through the line VI-VI of FIG. 4 .
FIG. 7 shows an expanded view of two bars in area VII of FIG. 6 .
FIGS. 8-10 show exemplary alternative embodiments according to the invention wherein the bars are “V” shaped and form a chevron pattern.
FIGS. 11-12 show two exemplary “V” shaped bars.
FIGS. 13-14 show alternative embodiments wherein the bars are inserted by a relieved end slot and retained by a single press-fit bar.
FIGS. 15-16 show an example of a multi-layer bar in two views in accordance with the invention.
FIG. 17 shows, in detail, a bar end design according to a preferred embodiment of the invention.
FIGS. 18-22 show various exemplary bar end sections in perspective wherein the bar thickness is varied across the width of the bar.
FIGS. 23-28 show various exemplary bars in accordance with the invention wherein the bar cross section is varied along the long dimension.
FIGS. 29-32 show in cross section several exemplary embodiments of iron type clubs according to the invention incorporating stacked bars of varied thickness.
DETAILED DESCRIPTION OF THE INVENTION
Referring for example to FIGS. 1-14 , the club head body 1 , 21 , 31 , 42 may be made of any material suitable for the construction of golf clubs and may include additional features such as a sole-plate on wood type clubs as are known in the art. The club head body 1 has a recess 2 in its front face 3 , 23 , 33 , 45 and optionally a cavity 4 , 24 or through hole within the recess, behind the impact face. A plurality of machined or otherwise formed bars 8 , 28 , 39 , 40 , 48 , 49 are fit contiguously into the recess in the face of the club head to form a faceplate having an impact face. The bars have three primary dimensions, length, width, and depth, with a frontwall 13 bounded by the two largest dimensions, length and width, sidewalls 12 bounded by the length and depth, and endwalls bounded by the width and depth. The depth dimension may be uniform or variable lengthwise as may the thickness of the material. Each endwall 11 may comprise a single surface which is perpendicular or angled with respect to the frontwall, e.g., the endwall can be shaped to form an interlocking surface which can engage a surface 5 , 25 cast or machined into the edge of the recess in the club head body thereby retaining the bars in the recess. The bars can be individually deflected in the direction perpendicular to the impact face when the impact face impacts a golf ball, and are preferably assembled in the recess with the sidewalls 12 in contact with each other. The frontwalls may be polished or treated mechanically or chemically to provide a textured impact face. The bars may fill the recess or be bordered by retainers which can be shaped to match the unfilled portion of the recess. If desired, a closed cavity may be provided beneath the bars, or the backside of the bars may be partially exposed through an opening in the rear surface of the club head.
The side edges 6 of the bars' frontwalls 13 may be machined before assembly such that a groove 10 , 26 is formed between adjacent bars and/or between the bars and any retainers 7 , 9 , 27 , 29 , 34 , 35 , 44 , 47 . A bar 37 , 48 side edge may be machined to provide a full length groove between adjacent bars. Alternatively, the bars 38 , 49 may be machined to provide a less than full length groove between adjacent bars. The bars may also be machined to form grooves in the frontwalls between the edges. The groves may be any shape (e.g., V shaped, square, or round); although, the V shaped grooves formed by two adjacent beveled edges are preferred. This allows for the economical production of precision machined grooves on a golf club face.
The bars may be retained in position in a club head by an interlocking arrangement, by bonding such as metallurgical or adhesive bonding or a combination thereof. For example, the bars may be retained in the club face by mating edges 5 forming a dovetail or other suitable geometry cast or machined into the recess 2 in the club head, e.g., spaced apart vertically or horizontally extending mating surfaces at opposed edges of the recess. In a preferred embodiment, the assembly of a “bars” iron is as illustrated in FIGS. 1-3 . A dovetail slot at opposed ends of a recess is machined into the heel 15 and toe 14 of the club head face 3 . A bottom retainer 9 , shaped at the bottom edge 19 to match the geometry of the bottom 17 of the club and having an interlocking surface at each end shaped to engage the dovetail slot, is press fit into the bottom of the dovetail. Typically six to eight bars 8 with the adjacent edges 6 machined at a 45 degree angle to a depth of 0.01 to 0.02 inches are stacked tightly in the dovetail slot. A retainer 7 shaped at the top edge 18 to match the geometry at the top 16 of the club head and having an interlocking surface at each end shaped to engage the dovetail slot is press fit into place above the stack securing the bars in position.
As illustrated in FIG. 4 , a bars iron may present the appearance of a conventional iron with horizontal grooves 26 formed at the contiguous edges of adjacent bars 28 . The club head body 21 is connected to a shaft 22 in the manner well understood in the art. The top and bottom retainers 27 , 29 may be of material similar to the body or may be chosen for aesthetic or mechanical properties. As seen in sectional views ( FIGS. 5-7 ), the bars 28 are backed by a small cavity 24 to permit deflection of the bars upon impact. The mating of the angled bar ends with the dovetail slot 25 at the edges of the recess securely retains the bars in the club head body.
A further feature of the “bars” approach to providing an insert for a golf club having an impact face is that the bars can be of any desirable material. For example, in putters it is desirable to achieve a soft feel so a polymeric material with a low modulus of elasticity may be selected for the bars. In an iron type club a highly elastic material with a non-linear modulus like NiTi may be selected for its ability to absorb and recover from high energy impacts. In a wood type club, materials of the highest hardness may be used to maximize flight distance.
The mechanical properties of the impact face may be influenced by varying the length, width, and arrangement of the bars. The bars may be rectilinear (i.e. straight) as in FIGS. 1 , 4 , 13 - 14 or shaped with a curve or bend as illustrated in FIGS. 8-10 . Straight bars may be arranged to extend horizontally as in FIGS. 4 , 13 vertically as in FIG. 14 , or at an angle relative to the plane of the ground when the club head is properly swung. As seen in FIGS. 8-10 , “V” shaped bars 37 - 41 , which may be symmetric 39 , 40 ( FIGS. 8-9 ) or asymmetric 41 ( FIG. 10 ), may be assembled in a V-down (FIGS. 8 , 10 ) or V-up ( FIG. 9 ) chevron pattern. As illustrated in FIG. 10 , retainers 35 may be secured by pins 36 .
As illustrated in FIGS. 13-14 , a retaining dovetail recess need not open to any one side, top, or bottom, of the club head face 45 . Rather, bars 48 , 49 may be inserted via a relieved end slot 43 and retained by a press-fit or pinned final retainer bar 44 , 47 . Vertical bars, as illustrated in FIG. 14 may be chosen to be uniform or vary in thickness and/or width towards the toe and heel. Thicker bars at outer ends of the club face may be used to provide hook and slice correction.
As illustrated in FIGS. 15-16 , the bars may be formed of uniform material or of laminated layers 52 , 53 , 54 . Laminated bars 50 may be designed to combine various material properties such as a hard surface with vibration damping, and shape memory. For example a beta titanium front surface layer 52 may be machined with groove forming indentations 55 . This provides the surface with high hardness, abrasion resistance and good strain recovery. This layer 52 may be bonded to a second layer 53 of polyurethane elastomer to provide vibration damping. A third layer 54 of super-elastic NiTi provides the bar 50 with a high degree of strain recovery from deflection and further vibration damping. As another example, thin layers of stainless steel or Beta Titanium may be laminated to provide a bar capable of much higher deflection without permanent damage. Such a bar will maintain contact with the ball longer for energy transfer and enhanced transfer of spin upon impact. Any number of layers may be laminated to form a single bar. The layers may or may not be the same thickness. The front surface layer of all the bars can be of the same material across an impact face to satisfy present USGA rules.
As illustrated in FIG. 17 , in a preferred embodiment of the invention, a bar 61 endwall is angled to form an interlocking surface which can engage the dovetail geometry of the spaced apart edges of the recess. The top may be machined at the side-edge to form a half-groove 62 . Preferably, a small chamfer 168 at the tip of the dove-tail wedge allows the bars to be more easily assembled in the recess and allows greater flexure of the bars at impact.
As illustrated in FIGS. 18-22 the bars 61 , 161 may have a uniform thickness ( FIG. 18 ) or varied thickness across the width of the bars ( FIGS. 19-22 ). The cross section thickness may vary linearly 162 or non-linearly in concave 164 , convex 165 , or stepped 166 shapes. The bar ends 163 are preferably the full uniform thickness in order to engage the club head body at the edges of the recess. Groups of such bars may be chosen for example to vary the thickness profile across the stack as illustrated in FIGS. 29-32 .
As illustrated in FIGS. 23-28 the bars 61 , 63 , 66 , 67 , 68 may have a uniform ( FIG. 23 ) or varied thickness ( FIGS. 24-28 ) lengthwise linearly or non-linearly. Thinner bars will feel softer and provide a larger zone of uniform response than thicker bars. A bar with a thinner center 67 , 68 will exhibit a larger sweet spot and directional correction for off center impacts. A continuous curve 68 provides a uniform stress distribution across the face while a stepped profile 67 creates discrete zones of response. A bar with a thin profile except a central bump 63 will provide a softened feel with controlled face deflection while retaining a stiff follow-on for distance. A bar with thin outer sections 66 reduces harsh feel of toe and heel impacts. A bar with an asymmetric thickness profile 64 will provide asymmetric response to impact. The thicker end of the bar will be stiffer, thus a golf ball is directed toward the thinner bar end. This design may be used for correction of a chronic hook or slice. Similar considerations apply to the design of stacks of bars such as illustrated in FIGS. 29-32 . By application of these principles in choosing and stacking bars in a club face, many different golf ball impact responses can be achieved.
The invention can be implemented in variations of the foregoing embodiments. For example, the length and direction of the bars could be varied as well within a single club face and/or a configuration of variously treated short bars could be bonded to backing bars and/or provided with mating surfaces in adjacent endwalls. Further, bars of uniform but differently processed (e.g. heat treated) material may used to provide a more even impact response across an impact face and/or smaller bars might be used to heighten this effect, e.g., short bars may be machined to provide mating surfaces at the end walls. Alternatively, short bars may have flat end walls and rely solely on adhesion to a backing bar for retention in the club head. The directions of bars may change one or more times across the impact face. In arrangements of this type, the adjacent endwalls and sidewalls of orthogonal bars may be shaped to provide mating surfaces to retain bars not in contact with the edges of the recess. Bars of mixed shape and orientation may be combined in various arrangements to provide desired properties such as differing groove and surface deflection directions as a function of the impact position on the impact face. Multiple layers of individual bars may be inserted in a club head recess, e.g., an outer layer of bars may be retained in the recess over a backing plate comprising an inner layer of backing bars to provide a fine tuned surface response. The exposed layer may be of a thin, uniform, and elastic material such as NiTi. Backing layers may be of any hardness, cross-section, and arrangement. In a preferred embodiment, the surface bars mate with edges of the recess for purposes of retention.
An advantage of preferred embodiments of the invention is the ability to provide a more uniform response to off-center hits. This can be accomplished with the “bars” approach by varying the thickness of the material of the bars over the impact face. Also, the mechanical properties may vary at different points in the impact face while presenting a uniform material surface. For example, bars heat-treated or otherwise processed in different ways either uniformly lengthwise or variably along a bar's length would allow the impact face to be fine tuned for its response characteristics. Multi-layer bars may incorporate several laminations of different materials specifically chosen for vibration dampening properties or elastic response or both. The various configurations of shape, orientation, and thickness of can be used to offset inherent imbalance and inertia effects in a club when hit off-center or to help compensate an inherently faulty swing. The back-face of the bars may comprise structural features such as a bump or island for the purpose of limiting the travel of a deflected bar upon impact with a ball.
Any of the previous examples might be used in conjunction. For example, alternating layers of vertical and horizontal bars might be used to fine tune the response of the impact face. Likewise, any other combination of the exemplary designs might be implemented varying the thickness, width, length, material, properties, and direction.
In addition to the forgoing description, the invention and preferred embodiments thereof may be further understood by consideration of the following examples.
EXAMPLES
Iron with Enhanced Off-Center Impact Response
Any of the long (i.e., irons numbered 1 to 5) type clubs may be enhanced for distance with consistency of control by providing an impact face with a larger area of uniform impact response. To this end, a club head body is provided with a recess in the form of a vertical dovetail slot in the face. A polished steel retainer, flat on top with the top front edge machined at a 45 degree angle to a depth of 0.02 inches, contoured on the bottom to match the bottom and sole of the club face, and machined into a dovetail wedge at each end, is press fit into the bottom of the dovetail slot. A series of 10 NiTi bars, about 0.13 inches wide, machined to a 10 degree angle at each end (with a 0.015 inch 45 degree chamfer at the wedge tip) are sized to fit snugly in the dovetail slot. The bars are about 0.1 inches deep at the ends of the frontwall. The side-edges of the front wall are machined at a 45 degree angle to a depth of 0.02 inches. The back side of each bar is machined in a parabolic contour lengthwise with the center of the 6 th bar machined to approximately half its depth; upper bars are machined more deeply than lower bars in sequence stepwise such that a rear view of the bars stacked in order shows a smooth parabolic contour along the heel to toe direction of the bars and a step-wise linear progression from top to bottom of the stack. The bars are stacked tightly together in the slot forming a precision V shaped groove at each adjacent edge. A top retainer of polished steel, flat on the bottom with the bottom front edge machined at a 45 degree angle to a depth of 0.02 inches, contoured on the top to match the top of the club face, and machined into a wedge at each end to fit tightly in the dovetail slot, is press fit into the top of the dovetail slot. In an on-center impact, the shaped impact deflection focuses energy otherwise dispersed across the face to a center line of thrust. In the case of a slightly off-center impact the shaped deflection of the face re-focuses the flight of ball in the intended direction with minimal loss of distance. The top to bottom thickness progression smooths and expands the sweet spot vertically for high and low impacts. Balls struck at the bottom of the impact face are increasingly directed upward to the desired loft and balls struck near the top of the impact face have a softer feel and longer contact time with the impact face.
Irons with Enhanced Spin and Directional Control.
An iron type club is provided with an insert of pointing “V” shaped bars as illustrated in FIGS. 8-10 . The V shape of the bars and grooves control the spin imparted to a golf ball upon impact. Upward pointing V bars ( FIG. 8 ) impart top-spin. Top-spin may be desired to keep a ball's trajectory low, for example when hitting against the wind, and to increase forward fairway bounce and roll. Downward pointing V bars ( FIG. 9 ) impart backspin. Backspin may be desired to increase aerodynamic lift of a ball in flight or to limit a ball's forward roll in chip-shots. The V shaped bars are inherently stiffer near the heel and toe, thus directing a ball hit on the heel or toe of the club toward center. An asymmetric chevron can be arranged to stiffen the toe or heel thus selectively shifting the sweet-spot.
The various illustrations demonstrate the potential to change properties across the club face while still conforming, if desired, with the one material constraint of the USGA rules. Numerous alternative arrangements, bar treatments, shapes, materials, and retaining arrangements may be imagined.
The foregoing has described the principles, preferred embodiments and mode of operation of the present invention. However, the invention should not be construed as being limited to the particular embodiments discussed. Thus the above-described embodiments should be regarded as illustrative rather than restrictive, and it should be appreciated that variations may be made in those embodiments by those skilled in the art without departing from the scope of the present invention as defined by the following claims.
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A striking face for golf clubs, such as a driver, iron or putter comprising a plurality of bars retained in the club head body and forming the striking surface. The bars which comprise the striking face according to the invention may be designed and arranged to provide enhanced performance of a golf club. The bars may also be machined economically before assembly of the golf club head to provide a precision grooved striking face at reduced cost.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to communications systems. More specifically, the present invention relates to systems and techniques for providing conference calling in digital telephone systems.
2. Description of the Related Art
Generally, communications systems transmit voice, video and/or data from one point to another. In certain applications, it is desirable to communicate between multiple points. In a voice context, this is achieved by `conference calling`. Conference calling allows each of a plurality of spatially separated participants to communicate contemporaneously with each other as though present in a shared environment.
In a conventional (land line) telephone system, voice quality for conference calls is maintained through the use of switches and amplifiers which sum and distribute the speech of those speaking to the participants in the conference call.
However, in digital wireless communication systems such as cellular telephone systems, conference calling is somewhat more problematic. This is due to the fact that speech in these systems is generally compressed at some point in transmission. Conference calling in this context conventionally requires decompression of compressed speech so that the signals may be summed as analog signals prior to any re-transmission to conference participants. This is due to the cost and complexity associated with digital signal summing schemes. Unfortunately, the compression, decompression, recompression and re-decompression of speech significantly degrades the quality thereof at the receiver. An excellent illustration of this problem may be found in a CDMA conference bridging system.
CDMA (Code Division Multiple Access) modulation is one of several techniques for facilitating communications in which a large number of system users are present. CDMA offers several advantages over other techniques known in the art such as TDMA (Time Division Multiple Access), FDMA (Frequency Division Multiple Access), and AM (Amplitude Modulation) schemes such as ACSSB (Amplitude Companded Single Sideband). The use of CDMA techniques in a multiple access communication system is disclosed in U.S. Pat. No. 4,901,307, entitled "SPREAD SPECTRUM MULTIPLE ACCESS COMMUNICATION SYSTEM USING SATELLITE OR TERRESTRIAL REPEATERS", the teachings of which are incorporated herein by reference. The use of CDMA techniques in a multiple access communication system is further disclosed in U.S. Pat. No. 5,103,459, entitled "SYSTEM AND METHOD FOR GENERATING SIGNAL WAVEFORMS IN A CDMA CELLULAR TELEPHONE SYSTEM", the teachings of which are also incorporated herein by reference.
CDMA systems often employ a variable rate vocoder to encode data so that the data rate can be varied from one data frame to another. An exemplary embodiment of a variable rate vocoder is described in U.S. Pat. No. 5,414,796, entitled "VARIABLE RATE VOCODER", the teachings of which are incorporated herein by reference. The use of a variable rate communications channel reduces mutual interference by eliminating unnecessary transmissions when there is no useful speech to be transmitted. Algorithms are utilized within the vocoder for generating a varying number of information bits in each frame in accordance with variations in speech activity. For example, a vocoder with a rate set comprising four rates may provide 20 millisecond data frames containing 20, 40, 80, or 160 bits, depending on the activity of the speaker. It is desired to transmit each data frame in a fixed amount of time by varying the transmission rate of communication. Additional details on the formatting of the vocoder data into data frames are described in U.S. Pat. No. 5,511,073, entitled "METHOD AND APPARATUS FOR THE FORMATTING OF DATA FOR TRANSMISSION", the teachings of which are incorporated herein by reference.
In a conventional CDMA conference bridging arrangement, the speech signals received from each of the participants are devocoded, summed then revocoded and re-transmitted to the participants. Devocoding involves detecting the rate of the received vocoded signal and decoding it accordingly. One technique for determining the rate of a received frame of vocoded data is disclosed and claimed in copending U.S. patent application Ser. No. 08/233,570, filed Apr. 26, 1994, U.S. Pat. No. 5,566,206, and entitled "METHOD AND APPARATUS FOR DETERMINING DATA RATE OF TRANSMITTED VARIABLE RATE DATA IN A COMMUNICATIONS RECEIVER", and U.S. patent application Ser. No. 08/126,477, entitled "MULTIRATE SERIAL VITERBI DECODER FOR CODE DIVISION MULTIPLE ACCESS SYSTEM APPLICATIONS", filed Sep. 24, 1993, abandoned, the teachings of both of which are incorporated herein by reference. According to these techniques, each received data frame is decoded at each of the possible rates. Error metrics, which describe the quality of the decoded symbols for each frame decoded at each rate, are provided to a processor. The error metrics may include Cyclic Redundancy Check (CRC) results, Yamamoto Quality Metrics, and Symbol Error Rates all of which are well-known in the art. A processor analyzes the error metrics and determines the most probable rate at which the incoming symbols were transmitted. This rate is used to decode the received signal.
In a conference bridging arrangement, the speech and/or background noise from each conference participant is vocoded and transmitted to a base station by a transmitter at each subscriber station. At the base station, the vocoded signals are received, devocoded, summed, revocoded and re-transmitted to the conference participants. At each subscriber location, the revocoded signals are re-devocoded. As mentioned above, this vocoding, devocoding, revocoding and re-devocoding severely degrades the quality of the received signals.
Hence there is a need in the art for a system and/or technique for maintaining voice quality in wireless digital conference calling systems.
SUMMARY OF THE INVENTION
The need in the art is addressed by the present invention which provides a conference calling system for a wireless communications channel. The invention is adapted for use with a channel having first, second and third participants communicating via first, second and third transmitters and receivers respectively. The inventive system includes a circuit for receiving an encoded signal from at least one of the transmitters. A second circuit determines which of the participants is speaking from the received encoded signal. A third circuit is provided for re-transmitting an encoded signal received from the speaking participant to the other participants. It should be noted that the exemplary embodiment for providing conference calling to three participants can easily be generalized to any number of participants and can include land-line participants.
In an illustrative implementation, the encoded signals are variable rate speech vocoded signals in which speech is vocoded at full rate, silence is vocoded at 1/8th rate and the 1/2 and 1/4 rates are used as transitional rates. In the illustrative implementation, the contents of the speaker's signal is identified by examining the rate of the received vocoded signals. When the speaker's vocoded signal is identified, it is re-transmitted without devocoding to the non-speaking participants in the conference call.
By re-transmitting the speaker's signal without de-vocoding, the quality of the received signal is preserved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the conference calling system of the present invention.
FIG. 2 is a block diagram illustrating the components of the base station of the conference calling system of the present invention.
FIG. 3 is a flow diagram illustrating the method of providing conference calling services in a wireless environment in accordance with the teachings of the present invention.
FIG. 4 is a block diagram of the control processor.
DESCRIPTION OF THE INVENTION
Illustrative embodiments and exemplary applications will now be described with reference to the accompanying drawings to disclose the advantageous teachings of the present invention.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
FIG. 1 is a block diagram of the conference calling system of the present invention. The system 10 includes first, second and third subscriber stations 12, 14 and 16, respectively, which communicate with a base station 18. (Those skilled in the art will appreciate that the invention is not limited to the number of subscriber stations shown.) In the exemplary embodiment, each of the subscriber stations includes an identical transmitter system 20 and a receiver system 40. In the illustrative embodiment, the user of the first subscriber station 12 is speaking and the users of the second and third stations (14 and 16) are listening. The transmitter system 20 is illustrated in FIG. 1 with respect to the first subscriber station 12. Speech data frames from s the user of the first subscriber station 12 are provided to a variable rate vocoder 22. In the exemplary embodiment, the variable rate vocoder 22 is implemented in the manner described in U.S. Pat. No. 5,414,796, the teachings of which have been incorporated herein by reference. The vocoder 22 processes the input speech data frame to provide a vocoded frame. The vocoder 22 provides frames of speech coded data at four different rates, referred to as full rate, half rate, quarter rate and eighth rate. A half rate packet contains approximately half the number of bits as a full rate packet, a quarter rate packet contains approximately one quarter the number of bits as a full rate packet and an eighth rate packet contains approximately one eighth the number of bits of a full rate packet.
The vocoded frame is then provided to a packetizer 24 which, in the illustrative embodiment, generates a set of cyclic redundancy check (CRC) bits for the frame and appends the CRC bits and a set of tail bits to the frame. In the illustrative embodiment, the packetizer 24 operates in accordance with the Telecommunications Industry Association's standard TIA/EIA/IS95-A Mobile Station-Base Station Compatibility for Dual Mode Wideband Spread Spectrum Cellular System.
The frame from the packetizer 24 is then provided to an encoder 26. The encoder 26 encodes the speech for error detection and correction. In the exemplary embodiment, the encoder 26 is a convolutional encoder, the design and implementation of which is well known in the art. The frame of encoded symbols is then provided to an interleaver 28.
The interleaver 28 reorders the encoded symbols of the frame in accordance with a predetermined reordering format. In the illustrative embodiment, for packets of less than full rate, the interleaver 28 generates duplicates of the reordered symbols in the packets to provide packets of a constant data rate. When the variable rate packet is half rate, the interleaver 28 introduces a factor of two redundancy, i.e., each symbol is repeated twice within the output packet. When the variable rate packet is quarter rate, the interleaver 28 introduces a factor of four redundancy. When the variable rate packet is eighth rate, the interleaver 28 introduces a factor of eight redundancy.
The packets are then provided to a data burst randomizer (DBR) 30. The data burst randomizer 30 removes the redundancy from the packets in accordance with a pseudo-random process as described in U.S. Pat. No. 5,535,239, the teachings of which are incorporated herein by reference. The data burst randomizer 30 selects one copy of the interleaved data symbols for transmission in accordance with a pseudo-random selection process and gates the other redundant copies of those symbols.
The selectively gated frame is then provided to a modulator 32 which modulates the frame for transmission. In the illustrative embodiment, the modulator 32 is a spread spectrum modulator as described in detail in the aforementioned U.S. Pat. Nos. 4,901,307 and 5,103,459, the teachings of which have been incorporated herein by reference. The modulated frame is then provided to an RF transmitter (TMTR) 34. The transmitter 34 upconverts and amplifies the signal for transmission through a duplexer 36 to an antenna 38.
The signal is transmitted by the first subscriber station 12 and received by the base station 18. In accordance with the present teachings, the signal received by the base station 18 is transmitted to the second and third subscriber stations 14 and 16, respectively, without devocoding if it is transmitted as a full rate speech signal.
FIG. 2 is a block diagram of the base station of the conference calling system of the present invention. As illustrated in FIG. 2, the signal is received by an antenna 42 of the base station and provided thereby to a receiver system 44 which processes the received signal. The receiver system 44 includes an RF receiver 46 which downconverts the received signals. The base station 18 does not know a priori which of the subscriber station users will be actively talking and which will be listening. Thus, the receiver 46 processes data frames received from the subscriber stations 12, 14 and 16 and passes the processed signals to first, second and third demodulators 47, 48 and 49, respectively, of multiple access receive subsystem 50. The demodulators 47, 48 and 49 demodulate the downconverted signals in accordance with the modulation scheme of the modulator 32 of the transmitter section 20 of the corresponding subscriber station. In the illustrative embodiment, the demodulators 47, 48 and 49 are CDMA demodulators as described in detail in the aforementioned U.S. Pat. Nos. 4,901,307 and 5,103,459.
The multiple access receive subsystem 50 further includes first, second and third combiners 51, 52 and 53, respectively, which receive input from the first, second and third demodulators 47, 48 and 49, respectively. The demodulated signal from the demodulators 47, 48 and 49 and other demodulators (not shown) which demodulate the same signal which traveled through different propagation paths to the base station 18 are shown as "Other Fingers" and provided to the associated diversity combiners 51, 52 or 53.
CDMA, by its inherent nature of being a wideband signal offers a form of frequency diversity by spreading the signal energy over a wide bandwidth. Therefore, frequency selective fading affects only a small part of the CDMA signal bandwidth. Space or path diversity is obtained by providing multiple signal paths through simultaneous links from a mobile user through two or more cell-sites. Furthermore, path diversity may be obtained by exploiting the multipath environment through spread spectrum processing by allowing a signal arriving with different propagation delays to be received and processed separately. Examples of path diversity are illustrated in U.S. Pat. No. 5,101,501 entitled "METHOD AND SYSTEM FOR PROVIDING A SOFT HANDOFF IN COMMUNICATIONS IN A CDMA CELLULAR TELEPHONE SYSTEM", and U.S. Pat. No. 5,109,390 entitled "DIVERSITY RECEIVER IN A CDMA CELLULAR TELEPHONE SYSTEM", the teachings of which are incorporated herein by reference.
The diversity combiners 51, 52 and 53 combine the signals to provide an improved estimate of the demodulated signal. In the illustrative embodiment, the diversity combiners 51, 52 and 53 are designed and constructed in accordance with the teachings of the above-reference U.S. Pat. No. 5,109,390, the teachings of which have been incorporated herein by reference.
The output of the first, second and third combiners 51, 52 and 53 is provided to first, second and third de-interleavers 54, 55, and 56, respectively. The de-interleavers re-order the demodulated symbols data in accordance with the predetermined re-ordering format as set by the interleaver 28 of each transmitter section 20 of each subscriber station.
The frames from the first, second and third de-interleavers 54, 55, and 56, respectively, are then provided to first, second and third decoders 57, 58 and 59, respectively, which decode the data. In the illustrative embodiment, the first, second and third decoders 57, 58 and 59 are multi-rate trellis decoders as described in detail in the aforementioned U.S. patent application Ser. No. 08/126,477.
In the illustrative embodiment, the receiver system 44 determines the rate of the received frame as an artifact of the decoding process which is performed, in the illustrative embodiment, by the multi-rate trellis decoders. Hence, a rate detector 60 is shown in the drawings as being provided by the trellis decoders 57, 58 and 59. The rate detector 60 determines an estimate of the rate of the signals sent by each of the subscriber stations. In an alternative embodiment, the rate detector can be a separate processor which estimates the rate of the received signal based on the energy of the received frame or on the energy of the received frame normalized by the energy of a pilot signal or by looking at gaps in the incoming signal or by a simple algorithm based on which of the users was speaking last.
The rate estimates are provided to a control processor 62. In the first example, the rate detector 60 provides a signal to the control processor 62 which indicates that the frame from the first subscriber station 12 was of a rate higher than the frames from the second and third subscriber stations 14 and 16. For example, the frame from the first subscriber station 12 may be a full rate frame and the frames from second and third subscriber stations 14 and 16 may be eighth rate frames, indicating that the user of the first station 12 is speaking and the users of the second and third stations 14 and 16 are listening. In response to this signal, the control processor 62 sends a signal to a switch 64 and a transmission system 66 which indicates that the signal from the first subscriber station 12 is to be sent to the second and third subscriber stations 14 and 16. The switch 64 then provides the trellis decoded signal received from the subscriber station having the highest rate frame (the first subscriber station 12 in the illustrative example) to an encoder 68 of the transmission system 66. Note that a significant feature of the present teachings is that the signal packet received at the highest rate is not speech (vocode) decoded. This eliminates the steps of devocoding the speech to analog, summing with other received signals, then revocoding prior to re-transmission thereby providing significant improvements in the quality of the speech signal received by the other stations in the conference.
The encoder 68 encodes the speech signal received from the switch 64 for error detection and correction. In the exemplary embodiment, the encoder 68 is a convolutional encoder, the design and implementation of which is well known in the art. The frame of encoded symbols is then provided to an interleaver 70.
The interleaver 70 reorders the encoded symbols of the frame in accordance with the reordering format as described above with respect to the interleaver 28 of the transmitter 20 of each base station. The output of the interleaver 70 is provided to a modulator 72.
The modulator 72 may be implemented in the same manner as the modulator 32 of the transmitter section 20 described above. The modulator 72 receives a `subscriber select` signal via a Walsh code from the control processor 62. In response to the subscriber select signal, the modulator 72 modulates the interleaved encoded signal to be received by the second and third subscriber stations 14 and 16 for the illustrative example of the user of the first subscriber station 12 (User #1) speaking. Walsh codes are known in the art. See for example, above-referenced U.S. Pat. No. 5,103,459, the teachings of which have been incorporated herein by reference.
The output of the modulator 72 is input to a transmitter 74. The transmitter 74 is an RF transmitter such as the transmitter 34 of FIG. 1. The output of the transmitter 74 is provided to an antenna 76 for transmission to the second and third subscriber stations 14 and 16.
In the event that there is a tie for the rate of the highest rate frame, switch 64 provides the decoded packet of the speaker that has tied for highest rate who was speaking last. For example, if the frames from first subscriber station 12 and second subscriber station 14 were both full rate frames. Then, control processor 62 would select the frame of the speaker who was last speaking and provide a signal to switch 64 indicating the selection. The output of the switch 64 is provided to the encoder 68 of the transmission system 66 and transmitted to the subscriber stations 12, 14 and 16 in the manner set forth above.
Returning to FIG. 1, the signal transmitted by the base station 18 is received by the second and third subscriber stations 14 and 16, respectively. Although receipt by the second station 14 is described in detail, it is understood that the design, construction and operation of the receiver sections of the first and third stations 12 and 16, respectively, with respect to the signal transmitted by the base station 18 is identical to that of the second station 14.
The signal transmitted by the base station 18 is received by the second subscriber station 14 by an antenna 38 and provided through a duplexer 36 to a receiver (RCVR) 84. The receiver 84 downconverts and amplifies the received signal and provides it to a demodulator 86. The demodulator 86 demodulates the received signal in accordance with modulation format of the modulator 72 of the base station 18. In the illustrative embodiment, the demodulator 86 is a CDMA demodulator as described in detail in the aforementioned U.S. Pat. Nos. 4,901,307 and 5,103,459.
The diversity combiner 88 is implemented in the same manner as the combiners 51, 52 and 53 of the base station 18 as described above and as disclosed by the above-reference U.S. Pat. No. 5,109,390, the teachings of which have been incorporated herein by reference.
The demodulated signal from the diversity combiner 88 is provided to a de-interleaver 90. The de-interleaver 90 re-orders the demodulated symbol data in accordance with a predetermined re-ordering format as set by the interleaver 70 of the base station 18.
The frame from the de-interleaver 90 is then provided to a decoder 92 which decodes the data. In the illustrative embodiment, the decoder 92 is a multi-rate trellis decoder as described in detail in the aforementioned U.S. patent application Ser. No. 08/126,477. The decoded data is then provided to a variable rate vocoder 94. The variable rate vocoder 94 reconstructs the speech data from the decoded bit data and provides it to the user of the second subscriber station 14 (User #2).
The third subscriber station is not described in detail as the transmitter section of each station is as described above with respect to that of the first subscriber station 12 and the receiver section of each station is as described above with respect to the second subscriber station 14.
FIG. 3 is a flow diagram 100 illustrating a method of providing conference calling services in a wireless environment in accordance with the teachings of the present invention. As illustrated in FIG. 3, at step 102, the base station 18 receives signals from all subscriber stations in a conference call. At step 104, the received signals are processed and, at step 106, the rates of the received signals are determined. At step 108, the control processor 62 checks to determine whether the rate of one of the frames is higher than the other two frames. If yes, then at steps 109 and 110, the highest rate frame is selected for transmission to the subscriber stations not selected for transmission.
As mentioned above, this is a significant feature of the present invention in that the signal packet received at full rate is not speech (vocode) decoded. This eliminates the steps of devocoding the speech to analog, summing with other received signals, then revocoding prior to re-transmission thereby providing significant improvements in the quality of the speech signal received by the other stations in the conference.
If there is a tie between the highest rate frames, the control processor 62 selects the tied highest rate frame belonging to the subscriber station which has spoken most recently in block 112 and is transmitted as described previously in block 110.
FIG. 4 illustrates an improved implementation of the control processor of the present invention. Control processor 200 could be substituted for control processor 62 of FIG. 2. In control processor 200 the rates of the frames determined by the decoder are filtered by low pass filters 202, 204 and 206. This prevents switch 64 from switching unnecessarily. For example if one speaker pauses momentarily in his discourse and during that pause a second speaker moves his chair, then without this filtering the switch would result in the undesirable transmission switching from the first speaker to the second speaker, followed by a switching back to the first speaker when he resumes his discourse. Low pass filters 202, 204 and 206 can be implemented by methods that are well known in the art.
The filtered rates from low pass filters 202, 204 and 206 are provided to decision means 208 which operates as described in FIG. 3 except the decision is based on the filtered rate and not on the current rate alone.
Thus, the present invention has been described herein with reference to a particular embodiment for a particular application. Those having ordinary skill in the art and access to the present teachings will recognize additional modifications applications and embodiments within the scope thereof. It is therefore intended by the appended claims to cover any and all such applications, modifications and embodiments within the scope of the present invention.
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A conference calling system for a wireless communications channel. The system is adapted for use with a channel having first, second and third participants communicating via first, second and third transmitters and receivers respectively. The system includes a circuit for receiving an encoded signal from at least one of the transmitters. A second circuit determines which of the participants is speaking from the received encoded signal. A third circuit is provided for re-transmitting an encoded signal received from the speaking participant to the other participants. In the illustrative implementation, the encoded signals are variable rate speech vocoded signals in which speech is vocoded at full rate, silence is vocoded at 1/8th rate and the 1/2 and 1/4 rates are used as transitional rates. In the illustrative implementation, the speaker's signal is identified by examining the rate of the received vocoded signals. When the speaker's vocoded signal is identified, it is re-transmitted without de-vocoding to the non-speaking participants in the conference call. By re-transmitting the speaker's signal without de-vocoding, the quality of the received signal is preserved.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to a gas spring, and more particularly to a gas spring which is applied to a hatch type door of a vehicle for keeping the door opened unless an external force to close the door is applied thereto.
2. Description of the Prior Art
In order to keep the hatch type door opened against the weight of the door itself, there has been proposed a telescopically movable gas spring which generally comprises a cylinder body pivotally connected to the vehicle body, a free-piston sealingly and slidably disposed in the cylinder body to divide it into a gas chamber and a liquid chamber, a main piston slidably disposed in the liquid chamber to divide it into first and second liquid chamber sections which are communicated with each other by only an orifice formed in the main piston, and a piston rod secured at its one end to the main piston and projecting axially from the cylinder body, the other end of the rod being pivotally connected to the door. When the door is under manual opening operation and the opening movement of its exceeds a predetermined degree, it is forced to open automatically against its own weight and keeps its full open position. This operation is achieved by a repelling force which is accumulated by the gas chamber when it is compressed upon closing of the door. Thus, in a cold season such as winter, there may occur a problem in that the gas volume in the gas chamber reduces considerably as compared with that in other seasons, thereby lowering the repelling force, so that the desirable operation of the gas spring is not achieved. In fact, it sometimes happens that the door closes spontaneously by its own weight after the door is manually opened to the fully open position.
SUMMARY OF THE INVENTION
Therefore, it is an essential object of the present invention to provide a gas spring which is free of the above-mentioned problem.
According to the present invention, there is provided a gas spring which comprises a cylinder, a piston axially slidably received in the cylinder to divide the interior of the cylinder into first and second chambers, a piston rod connected at its one end to the piston and extending therefrom through the second chamber to project axially outwardly from the cylinder, first means for providing a passage between the first and second chambers only when the piston moves in a direction to contract the second chamber, second means for providing a passage between the first and second chambers only when the piston rod is pushed in a direction against the piston by a force greater than a predetermined degree, and third means for providing a passage between the first and second chambers only when the piston is positioned within a predetermined area in the cylinder.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will become clear from the following description when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a rear view of a motor vehicle having a hatch type door which employs gas springs according to the present invention,
FIG. 2 is a sectional view of a gas spring according to the present invention,
FIG. 3 is an exploded view of an essential portion of the gas spring of the present invention; and
FIGS. 4A, 4B, 4C and 4D are partial enlarged sectional views of the gas spring of the invention, respectively showing operating conditions of the gas spring.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, there is illustrated a rear view of a motor vehicle M having a hatch type door D which is hinged to the vehicle body. Two gas springs 10 according to the present invention are mounted to the vehicle M.
Referring to FIG. 2, there is shown the gas spring 10 of the pesent invention. The gas spring 10 comprises a cylinder body 12 having a cylindrical chamber 14 formed therein. An open end of the cylinder body 12 is plugged with a cap member 16 to which a joint member 18 is fixed. The joint member 18 is pivotally connected to its counterpart (not shown) mounted on the vehicle body for achieving pivotal movement of the gas spring 10 relative to the vehicle body. A free-piston 20 is axially slidably and sealingly received in the cylindrical chamber 14 to divide the same into a gas chamber 22 and a liquid chamber 24. Within the gas chamber 22 is contained a highly compressed gas, such as a nitrogen gas, while within the liquid chamber 24 is contained a working liquid. An O-ring 26 is mounted to the free-piston 20 to assure isolation between these two chambers 22 and 24. A main piston 28 is axially slidably received in the liquid chamber 24 to divide the same into first and second liquid chamber sections 24a and 24b. The cylinder body 12 is slightly expanded at a portion defining the first liquid chamber section 24a to provide an axially extending groove 24c merged with the section 24a. The main piston 28 is formed with a first orifice means 30 which can provide a communication between the first and second liquid chamber sections 24a and 24b. As will become clear from the following description, the first orifice means 30 is closable by an O-ring 32.
As is clearly shown in FIG. 3, the main piston 28 is formed with axially spaced first and second land portions 34 and 36 between which a port portion 38 is formed. The first land portion 34 is formed with a plurality of equally spaced openings 34a which communicate the first liquid chamber section 24a (see FIG. 2) with the port portion 38, and the second land portion 36 is formed with a plurality of axially extending grooves 36a which communicate the port portion 38 with the second liquid chamber section 24b (see FIG. 2). Thus, it will be seen that the openings 34a, the port portion 38 and the grooves 36a constitute the above-mentioned first orifice means 30. The O-ring 32 is loosely coupled in the port portion 38, but it is capable of closing the grooves 36a when brought into contact with the second land portion 36.
The main piston 28 is formed with a splined center hole 40 into which a splined base portion 42a of a piston rod 42 is axially movably received. As is seen from FIG. 2, the piston rod 42 extends axially outwardly from the cylinder body 12 and terminates at a portion to which a joint member 41 is fixed. The joint member 41 is pivotally connected to its counterpart (not shown) mounted on the hinged door D for achieving pivotal movement of the gas spring 10 relative to the door D. The spline connection between the hole 40 of the main piston 28 and the base portion 42a of the piston rod 42 is loosely made so as to define a second orifice means 44 which can provide a communication between the first and second liquid chamber sections 24a and 24b. As will become clear as the description proceeds, the second orifice means 44 is also closable by an annular valve member 46. The base portion 42a of the piston rod 42 is formed at its axially extream end with a threaded bolt portion 42b which is projected into the first liquid chamber section 24a when the base portion 42a is properly held in the splined hole 40 of the main piston 28.
As will be seen from FIG. 2, a nut 48 is secured to the bolt portion 42b for holding the annular valve member 46 between the nut 48 and the main piston 28. An annular spring seat 50 is securely mounted on the piston rod 42 at a position within the second liquid chamber section 24b. A coil spring 52 is compressed between the spring seat 50 and the main piston 28 so as to bias the piston 28 toward the nut 48, that is, in a direction to allow the annular valve member 46 to assume its close position.
A stopper member 54 for the spring seat 50, a sealing member 56 for sealing the second liquid chamber section 24b and a guiding bush 58 for the piston rod 58 are stationarily held in the other open end of the cylinder body, in a manner as best shown in FIG. 2.
Operation of the gas spring 10 will be described with reference to the drawings, especially FIGS. 4A to 4D. For easy understanding of the operation, the explanation of it will be made in accordance with the movement of the hinged door D to which the gas spring 10 is connected.
When the door D is under opening operation and comes into a position where the door D is almost full opened, the gas spring 10 shows a state as depicted by FIG. 4A. As will be seen from this drawing, as the hatch door D is moved to its full open position, the piston rod 42 moves rightward together with the main piston 28. During the rightward (or upward in actual use) movement of the piston 28, the O-ring 32 opens the first orifice means 30 causing the working liquid in the second liquid chamber section 24b to flow into the first liquid chamber section 24a as indicated by arrows. However, during this movement, the annular valve member 46 is kept closing the second orifice means 44 by the action of the biasing force applied thereto by the spring 52 and the liquid pressure in the reducing second liquid chamber section 24b. Thus, at the final stage of the opening operation of the hatch door D, it is compelled to move slowly.
When the hatch type door D is swung up to its full open position, it begins closing movement by its own weight. In this initial stage of the closing movement of the door D, the gas spring 10 shows a state as depicted by FIG. 4B. As will be seen from this drawing, with the door D beginning to close, the piston rod 42 moves slightly in the leftward direction inducing a slight leftward movement of the main piston 28 by the action of the spring 52. Thus, in this condition, the O-ring 32 comes into contact with the second land portion 36 of the main piston 28 thereby to block the first orifice means 30. Further in this condition, the annular valve member 46 keeps its close position by the action of the biasing spring 52 and the liquid pressure in the second liquid chamber section 24b. With these manners, the first and second liquid chamber sections 24a and 24b becomes isolated from each other. With no passage between these sections, the leftward movement (or downward movement in actual use) of the main piston 28 and thus that of the piston rod 42, which would be induced by the weight of the door D, are stopped. Thus, the door is left at the substantially full open position. Now, it is to be noted that keeping the door D in its full open position is assuredly made irrespective of condition of the gas chamber 22. Thus, the above-mentioned problem encountered in the conventional gas spring does not occur.
When, in order to close the door D, an external force greater than a predetermined degree is applied to the door D, it begins closing movement. With this, as will be seen from FIG. 4C, a leftward displacement of the piston rod 42 relative to the main piston 28 occurs thereby to open the second orifice means. Thus, during the closing movement of the door D, the piston rod 42 and thus the main piston 28 moves leftward allowing the working liquid in the first liquid chamber section 24a to flow into the second liquid chamber section 24b as indicated by arrows. Thus, the closing movement of the door D is smoothly made.
When, now, the door D comes into a position where the door D is almost full closed, the gas spring 10 shows a state as depicted by FIG. 4D. In this condition, the main piston 28 comes to the area where the axially extending groove 24c is located. With the groove 24c thus communicating the first and second liquid chamber sections 24a and 24b, the main piston 28 is leftwardly shifted and brought into contact with the annular valve member 46 to close the second orifice means 44 by the action of the spring 52. Thus, during the closing movement of the door D at its final stage, the main piston 28 moves leftward together with the piston rod 42 causing the working liquid in the first liquid chamber section 24a to flow into the second liquid chamber section 24b as indicated by arrows. It is to be noted that the final stage closing movement of the door D can be quickly made if the groove 24c has a larger size.
As has been mentioned hereinabove, since the gas spring 10 according to the present invention is constructed to have a state, as depicted by FIG. 4B, in which two liquid chamber sections 24a and 24b divided by a piston 28 to which a piston rod 42 is connected are isolated from each other, the door D can keep its full open position irrespective of the condition of the gas chamber 22. Thus, the before-mentioned problem encountered in the conventional gas spring originating from the pressure shortage in the gas chamber in a cold season does not occur in the present invention.
Although, in the above, description is made with respect to a construction having a free-piston 20 by which the gas chamber 22 and the liquid chamber 24 are bounded, it is also available to fill the entire of the cylinder proper 12 with a compressed gas without using such free-piston. In this construction, similar function to that mentioned above is achieved as will be easily understood by those skilled in the art.
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A gas spring for a hatch type door is disclosed, which comprises a cylinder, a piston received in the cylinder to divide the same into first and second chambers, a piston rod connected to the piston, a first device for providing a passage between the first and second chambers only when the piston moves in a direction to contract the second chamber, a second device for providing a passage between these chambers only when the piston rod is pushed against the piston by a force greater than a predetermined degree, and a third device for providing a passage between these chambers only when the piston is positioned within a predetermined area in the cylinder.
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This is a division, of application, Ser. No. 560,348 U.S. Pat. No. 4,520,176 filed Dec. 12, 1983 which is a continuation-in-part of application Ser. No. 430,187, filed on Sept. 30, 1982, abandoned.
The present invention relates to textile finishing compositions, particularly to textile finishing compositions for imparting durable press properties to treated textile materials and more particularly to a process for treating textile materials to impart durable press properties thereto.
BACKGROUND OF THE INVENTION
Durable press resins, also known as "aminoplast resins", have been described in U.S. Pat. No. 4,300,898 to North, for treating textile materials to impart durable press properties and dimensional stability to treated textile materials. These durable press resins, such as methylolated ureas or methylolated urea based derivatives which are obtained from the reaction of formaldehyde and urea or urea based derivatives generally contain 2.2 to 4.2 weight percent of formaldehyde.
Textile materials treated with the durable press resins generally release formaldehyde either present in the durable press resin and/or through the hydrolysis of unreacted methylol groups. The formaldehyde causes unpleasant odors and is a suspected health hazard. Therefore, it is preferred that textile materials finished with durable press resins be free of formaldehyde or at least have very low levels of formaldehyde and have as few as possible unreacted methylol groups.
In order to reduce the formaldehyde level on treated fabrics, scavengers such as cyclic ethylene urea, propylene urea and certain nitrogen-containing heterocyclic compounds have been employed. Also, U.S. Pat. No. 3,723,058 discloses reacting formaldehyde with phthalimide to remove the formaldehyde.
Another possible method of reducing the formaldehyde level is to apply a conventional aminoplast resin to textile materials at low levels; however, it does not give satisfactory durable press properties.
Surprisingly, it has been found that satisfactory durable press properties may be achieved if an aldehyde is added to a low level of aminoplast resin. Moreover, it has been found that the addition of the aldehyde does not substantially increase the amount of free formaldehyde on the textile materials. In addition, durable press properties can be achieved at lower costs and with less potential toxicological problems in the work environment as well as for the consumer.
Therefore, it is an object of the present invention to provide textile finishing compositions for treating textile materials. Another object of this invention is to provide textile finishing compositions which impart softening and durable press properties to textile materials. A further object of this invention is to provide a textile material having low formaldehyde levels, a soft hand, durable press properties and dimensional stability characteristics.
SUMMARY OF THE INVENTION
The foregoing objects and others which will become apparent from the following description are accomplished in accordance with this invention, generally speaking, by providing a textile finishing composition comprising (1) a diluent and (2) a durable press resin composition in an amount of at least 0.18 percent by weight based on the weight of the diluent and durable press resin composition, said durable press resin composition consisting of (a) an aminoplast resin and (b) an aldehyde, in which the weight ratio of aldehyde to aminoplast resin is from about 0.05 to 0.6. The textile finishing composition is combined with an acid catalyst and applied to textile materials to impart durable press and dimensional stability properties thereto. In addition to providing improved durable press properties and dimensional stability characteristics, the treated textile materials have a low level of formaldehyde and a soft hand.
DETAILED DESCRIPTION OF THE INVENTION
The aminoplast resins which are used in the durable press resin compositions of this invention are well known in the art. Suitable examples of aminoplast resins are the urea formaldehydes, e.g., propylene urea formaldehyde, and dimethylol urea formaldehyde; melamine formaldehyde, e.g., tetramethylol melamines, and pentamethylol melamines; ethylene ureas, e.g., dimethylol ethylene urea, dihydroxy dimethylol ethylene urea, ethylene urea formaldehyde, hydroxy ethylene urea formaldehyde; carbamates, e.g., alkyl carbamate formaldehydes; formaldehyde-acrolein condensation products; formaldehyde-acetone condensation products; alkylol amides, e.g., methylol formamide, methylol acetamide; acrylamides, e.g., N-methylol acrylamide, N-methylol methacrylamide, N-methylol-N-methacrylamide, N-methylmethylol acrylamide, N-methylol methylene-bis(acrylamide), methylene-bis(N-methylol acrylamide); chloroethylene acrylamides; diureas, e.g., trimethylol acetylene diurea, tetramethylol-acetylene diurea; triazones, e.g., dimethylol-N-ethyl triazone, N,N'-ethylene-bis dimethylol triazone, halotriazones; haloacetamides, e.g., N-methylol-N-methylchloroacetamide; urons, e.g., dimethylol uron, dihydroxy dimethylol uron; and the like.
Other aminoplast resins which may be used in the compositions of this invention may be represented by the formulas: ##STR1## wherein R 1 is hydrogen, a lower alkyl radical or a radical from a saturated or unsaturated aldehyde, R 2 is hydrogen, a lower alkyl radical or a radical represented by the formula ##STR2## R 3 is hydrogen or a methyl radical, R 4 is hydrogen or a lower alkyl radical, R 5 is hydrogen, a lower alkyl radical or CHR 1 OR 4 , with at least one R 5 being CHR 1 OR 4 , R 6 is a lower alkyl radical or hydroxy alkyl radical, R 7 is hydrogen, hydroxy radical, or lower alkyl radical, R 8 is hydrogen, a lower alkyl radical, an alkanol radical, or an alkenol radical, X is oxygen or sulfur, and a is a number of from 1 to 6. Sulfur containing groups such as ##STR3## or sulfonium radical may be substituted for the ##STR4## group. Mixtures of two or more aminoplast resins may be employed in the compositions of this invention.
Suitable examples of aldehydes which may be used in the compositions of this invention are saturated and unsaturated aliphatic aldehydes having from 1 to 20 carbon atoms, such as formaldehyde, ethanal, propanal, propenal, propynal; isomers of butanal, pentanal, hexanal, heptanal, octanal, nonanal, decanal, undecanal, dodecanal, tridecanal, tetradecanal, pentadecanal, hexadecanal, heptadecanal, octadecanal, nonadecanal, ecosanal, butenal, hexenal, undecenal, furfural and the like. Other examples of substituted saturated and unsaturated aldehydes having from 1 to 20 carbon atoms are haloalkanals, such as chloroethanal, dichloroethanal, bromal, chloral, 2-bromopropanal, 2-chloropropanal, 3-chloropropanal, 2-chloro-2-methylpropanal, 2,3-dibromopropanal, 2,3-dichloropropanal, 2,2,3-trichloropropanal, 4-chlorobutanal, 2,3-dichlorobutanal, 2,2,3-trichlorobutanal and the like; hydroxyalkanals such as glycolaldehyde, 2,3-dihydroxypropanal, 3-hydroxybutanal, 4-hydroxypentanal, 3-hydroxy-2-methylpentanal and the like; alkylalkanals such as 2,2-dimethylpropanal, 2-ethylbutanal, 2-methylbutanal, 3-methylbutanal, 2-ethylhexanal, and the like; alkoxyalkanals such as ethoxyethanal, methoxyethanal and the like; oxoalkanals such as glyoxal, methylglyoxal, 2-phenoxypropanal, 4-methyl-2-oxopentanal, 2-oxopentanal, 4-oxopentanal and the like; haloalkenals such as 2-chloropropenal, 2-chlorobutenal and the like; and alkoxyalkenals such as 3-ethoxybutenal. Examples of aromatic substituted or unsubstituted aldehydes are benzaldehyde, tolualdehydes, salicylaldehyde, 1-phenylpropynal, 2-benzylidenebutanal, 2-benzylideneheptanal, hydroxybenzaldehydes, anisaldehyde, vanillin, piperanal, cinnamaldehyde, carboxybenzaldehydes and the like.
Diluents which are employed in the textile finishing compositions of this invention are water and aliphatic alcohols having up to 8 carbon atoms. Examples of suitable aliphatic alcohols are methanol, ethanol, propanol, butanol, hexanol and octanol.
The amount of durable press resin composition present in the textile finishing composition is not critical and may range from about 0.18 percent by weight up to about 72 percent by weight and more preferably from about 0.2 percent by weight to about 65 percent by weight based on the weight of the diluent and the durable press resin composition.
Preferably, the weight ratio of aldehyde to aminoplast resin present in the durable press resin composition ranges from about 0.05 to 0.6 and more preferably from about 0.1 to about 0.5.
The amount of diluent present in the textile finishing composition may range from about 99.82 to 28 percent by weight and more particularly from about 99.8 to 35 percent by weight based on the weight of the diluent and the durable press resin composition.
A softening agent or softener may be incorporated in the textile finishing compositions of this invention to impart a soft hand to textile materials treated therewith. The term "softening agent" or "softener" includes any material which may be combined with the composition of this invention to impart a soft hand to treated textile materials.
Softeners which may be added to the compositions of this invention are well known in the art. Examples of suitable softeners are organopolysiloxanes which are capable of being crosslinked. The crosslinkable organopolysiloxane compositions contain organopolysiloxanes having the general formula ##STR5## and a crosslinking agent such as a silane having the general formula
R.sub.m.sup.9 Si(Y).sub.4-m
or siloxanes having --Si--O--Si-- linkages and the remaining valences of the silicon atoms are satisfied by R 9 and Y, in which R 9 is a monovalent hydrocarbon radical having up to 18 carbon atoms and Y is a hydrolyzable group, such as an acyloxy, oximo, alkoxy, aryloxy, halogen, aminoxy, amido or phosphato group, in which the siloxanes have an average of at least 3 hydrolyzable groups per molecule, b is a number of from 1 to 1000, and m is 0 or 1.
Catalysts such as metallic salts of carboxylic acid may be used with organopolysiloxanes to promote crosslinking. Examples of suitable salts are carboxylic acid salts of tin, zirconium or titanium. Specific examples of suitable catalysts are dibutyltin dilaurate, tin octoate, tin oleate and the like.
Further examples of softening agents which may be added to the compositions of this invention are non-crosslinkable polydiorganosiloxanes having the general formula ##STR6## in which R 9 and b are the same as above.
Other softening agents which may be used in the compositions of this invention are those obtained from the addition of organopolysiloxanes having silicon-bonded hydrogen atoms to organopolysiloxanes having silicon-bonded aliphatically unsaturated groups. Organopolysiloxanes containing silicon-bonded hydrogen may be represented by the general formula ##STR7## in which R 9 is the same as above, e has a value of from 1.0 to 2.5, f has a value of from 0.005 to 2.0 and the sum of e+f is equal to from 1.005 to 3.0.
The organopolysiloxanes containing silicon-bonded hydrogen may also be copolymers containing an average of at least one unit per molecule of the formula ##STR8## with the remaining siloxane units of the organopolysiloxane having the average formula ##STR9## where R 9 and e are the same as above, e' has a value of from 0 to 2, f' has a value of from 1 to 2, and the sum of e'+f' is equal to from 1.0 to 3.0.
Generally, the copolymers contain from 0.5 to 99.5 mole percent of siloxane units of the formula ##STR10## and from 0.5 to 99.5 mole percent of siloxane units of the formula ##STR11## where R 9 , e, e' and f' are the same as above.
The organopolysiloxanes containing silicon-bonded aliphatically unsaturated groups may be represented by the formula ##STR12## where R 9 , e and f are the same as above and R 10 represents a silicon-bonded aliphatically unsaturated group such as a vinyl or allyl radical. These organopolysiloxanes containing aliphatically unsaturated groups may also be copolymers having siloxane units of the formula ##STR13## where R 9 , R 10 , e', f' and the sum of e'+f' are the same as above
Generally, the copolymers contain from 0.5 to 99.5 mole percent of units having the formula ##STR14## and from 0.5 to 99.5 mole percent of units having the formula ##STR15## where R 9 , R 10 , e, e' and f' are the same as above.
Any catalyst capable of promoting the addition of silicon-bonded hydrogen to silicon-bonded aliphatically unsaturated groups may be used in preparing these softeners. Preferably, the catalyst is platinum or a platinum compound or complex.
The silicone softeners may also contain other functional groups. Examples of such softeners are copolymers of aminofunctional polysiloxanes containing units of the formula ##STR16## and units of the formula ##STR17## wherein R 10 and e are the same as above, R 11 which may be the same or different is a divalent hydrocarbon radical having from 1 to 10 carbon atoms and g=0, 1, or 2.
Other softeners which may be used are copolymers of ureidofunctional polysiloxanes having unis of the formula ##STR18## and units of the formula ##STR19## where R 9 and R 11 are the same as above.
Softeners containing mercaptofunctional groups such as mercaptofunctional polysiloxanes having units of the formula ##STR20## and units of the formula ##STR21## may be employed, where R 9 , R 11 and e are the same as above and h is a number of from 1 to 3.
Suitable examples of monovalent hydrocarbon radicals represented by R 9 are alkyl radicals having from 1 to 18 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, amyl, hexyl, octyl, decyl, dodecyl, and octadecyl; alkenyl radicals having from 1 to 18 carbon atoms such as vinyl, allyl, butenyl, butadienyl, 1-pentenyl, 1-decenyl, and 1-octadecenyl; aryl radicals such as phenyl, napthyl, and anthryl; aralkyl radicals such as phenylmethyl, phenylethyl, or phenylpropyl, or alkaryl radicals such as tolyl, xylyl, ethylphenyl; hydroxy and carboxy substituted hydrocarbon radicals such as hydroxyphenyl, carboxyphenyl, hydroxybenzyl, carboxybenzyl, hydroxytolyl and hydroxyxylyl, carboxytolyl and carboxyxylyl radicals.
Specific examples of divalent radicals represented by R 11 are ethylene, propylene, butylene, hexylene, octylene, decylene, ethenylene, propenylene, 1-butenylene, 2-butenylene, cyclohexylene, 3-cyclohexen-1,2-xylene and naphthenylene.
Other organofunctional silicone softeners which may be included in the compositions of this invention are the silylated polyethers described in U.S. Pat. Nos. 4,312,993 and 4,331,797 to Martin which are incorporated herein by reference.
Also, compositions containing silanol terminated polyorganosiloxanes and the silylated polyethers described in U.S. Pat. Nos. 4,312,993 and 4,331,797 to Martin can be used as softeners in the compositions of this invention.
Another class of silicone softeners which may be included in the textile finishing compositions of this invention are those described in U.S. Pat. No. 4,184,004 to Pines, which is incorporated herein by reference. These softeners consist of organosilicone terpolymers containing a plurality of reactive epoxy groups and a plurality of polyoxyalkylene groups. These organosilicone terpolymers may be prepared by the platinum catalyzed addition of an ethylenically unsaturated epoxy compound and an ethylenically unsaturated polyoxyalkylene organic radical free of olefinic unsaturation.
Organic softening agents may also be used in the textile finishing compositions of this invention in the presence or absence of the above silicone softeners. Suitable examples of organic softeners are fatty amides, fatty acid amines, and fatty acid amido amines; amido amines with mono- and diglycerides, quaternized ethoxylated fatty acid amines, hydroxyethyldiethylammonium sulfate and stearic quaternary ammonium compounds; fatty acid esters such as stearates, glycerol stearates, diethylene glycol stearates, and sulfonated fatty acid esters of polyethylene glycols and diethylene glycols; oxyalkylene polymers such as oxyethylene polymers, oxypropylene polymers, and copolymers thereof, salts of long-chain alcohols and fatty alcohol/fatty acid amide blends; fatty acids such as lauric, myristic, palmitic, oleic, and stearic acids; diethylene dipropyl benzoates; polyethylene polymers and sodium hydrocarbon sulfates. The softening agent may be added directly to the textile finishing compositions, or they may be emulsified or dissolved in water or organic solvents and then added to the finishing compositions.
When the softening agent is added to the textile finishing compositions, it is preferred that it be present in an amount such that the resultant finishing bath used for treating textile materials will contain from about 0 to about 8 parts by weight of softening agent per 100 parts by weight of finishing composition. The softening agent may be dissolved in aliphatic alcohols such as methanol, ethanol, butanol, hexanol and octanol.
The textile finishing compositions of this invention may be prepared by mixing the diluent with the durable press resin composition, i.e., aminoplast resin and aldehyde, in any order and at temperatures ranging from about 10° to 90° C.
The textile finishing compositions may be applied to any textile materials. Examples of suitable textile materials are cotton, rayon, polyester, polypropylene, polyethylene, polyurethane, polyamide, wool, hemp, natural silk, cellulose acetate and polyacrylonitrile fibers as well as mixtures of these fibers. The textile materials may consist of staple or monofilament fibers and fabrics made thereof.
The textile finishing compositions of this invention may be applied to the textile materials by any means known in the art, such as by spraying, immersion, foaming, padding, calendering or by gliding the fibers across a base which has been saturated with the compositions of this invention.
A preferred method for treating textile materials is to use a finishing bath containing a solution, dispersion or emulsion of the textile finishing compositions, i.e., durable press resin composition, diluent, acid catalyst and softener, if desired. Also, the finishing bath composition may be further diluted with the same diluent or at least a diluent which is compatible with the diluent used in the textile finishing composition. Preferably, the additional diluent is water or an aliphatic alcohol having from 1 to 8 carbon atoms.
The finishing bath preferably contains from 0.1 to about 99 parts by weight, and more preferably from about 5 to 50 parts by weight of the textile finishing composition and from about 1 to 10 parts by weight of acid catalyst per 100 parts by weight of finishing composition. The amount of additional diluent added to the finishing bath may range from 0 to 99.4 parts by weight and more preferably from about 10 to 75 parts by weight per 100 parts by weight of finishing composition and the amount of softening agent, when present, may range from about 0 to about 8 parts by weight and more preferably from about 1 to 5 parts by weight per 100 parts by weight of finishing composition.
When the textile finishing compositions are used in the form of an emulsion, any of the known surfactants can be used as emulsifying agents, including the anionic, cationic, nonionic and amphoteric surfactants.
Suitable examples of acid catalysts which may be used in the finishing bath are water soluble metal salts such as magnesium chloride, magnesium nitrate, magnesium sulfate, magnesium dihydrogen phosphate, zinc nitrate, zinc chloride, zinc tetrafluoroborate, aluminum chlorohydrate, aluminum chloride and mixtures of two of the above salts; water soluble ammonium and amine salts such as ammonium chloride, ammonium sulfate, aminomethylpropanol hydrochloride and aminomethylpropanol nitrate; ammonium and amine salts in combination with the metal salts described above; acids such as oxalic acid, gluconic acid, phosphoric acid, tartaric acid, maleic acid, p-toluenesulfonic acid and acetic acid; and combinations of the above acids with the above described metal salts.
The aminoplast resin component and the water soluble acid catalyst component should be kept separate until ready for use due to the instability of the mixture. The other components of this invention may be combined together in any order. It is, however, preferred that the other components be added to the aminoplast resin component.
The amount of the textile finishing composition of this invention which is applied to the textile material depends on the desired properties of the treated material. Generally, it is preferred that the textile material be treated with from about 0.1 to 25 percent by weight of textile finishing composition, and more preferably from about 0.2 to 20 percent by weight of the textile finishing composition, based on the weight of the textile material.
The textile material treated with the composition of this invention is heated at an elevated temperature, e.g., from about 80° to 200° C. for a brief period of time; e.g., from about 20 seconds to about 15 minutes. Alternatively, the treated textile material can be dried below the above temperature range, e.g., from about 50° to 95° C. for a brief period of time, e.g., from 1 to 10 minutes, and then cured at an elevated temperature, e.g., from 125° to 200° C. for an even briefer period of time, e.g., 15 to 60 seconds.
Textile materials treated with the finishing compositions of this invention exhibit dimensional stability and good durable press properties which are common to textile materials treated heretofore with aminoplast resins. The addition of the aldehyde in the present invention, however, permits a reduction of the aminoplast resin component of from 57 to 95 percent without adversely increasing the amount of formaldehyde present on the treated textile material, and without affecting the durable press properties and dimensional stability characteristics. Heretofore, when the level of aminoplast resin was reduced in conventional systems, in order to lower the formaldehyde levels on the treated fabric, poor durable press properties and dimensional stability characteristics were observed.
The addition of softener to the textile finishing compositions of this invention does not alter the durable press properties and dimensional stability characteristics of the fabric nor formaldehyde levels on the treated textile material. Textile materials treated with the textile finishing compositions of this invention containing softener have a softer hand than those treated with the textile finishing compositions alone or with other conventional aminoplast resins. Furthermore, because the amount of aminoplast resin component required in the present invention to obtain durable press properties is significantly less than that required heretofore, the textile finish is significantly more economical.
Other substances which may be incorporated in the compositions of this invention are agents which improve abrasion resistance of the treated fibers, materials which improve the fragrance of the treated textile materials, antistatic agents, lubricants, fire retardant agents, soil resistant materials, other hydrophilic, oleophilic, or hydrophobic agents and soil release materials such as those described in U.S. Pat. Nos. 3,595,141 and 3,377,249 to Marco.
Specific embodiments of this invention are further illustrated in the following examples in which all parts and percentages are by weight unless otherwise specified. The amount of formaldehyde present on the treated textile materials is determined in accordance with the procedure described in the Technical Manual of the American Association Of Textile Chemists And Colorists (AATCC - Test No. 112-1978). The dimensional stability and durable press ratings are determined in accordance with AATCC test method number 135-1978 and 124-1978, respectively.
EXAMPLE 1
Several compositions are prepared by dispersing the ingredients shown in Table I in water. The compositions are padded onto samples of polyester/cotton (65/35) fabric at 50 percent wet pick-up. The fabric is dried for 60 seconds at 120° and cured for 20 seconds at 204° C. The treated fabric is then evaluated for (a) parts per million formaldehyde; (b) dimensional stability after five home launderings; and (c) durable press properties after five home launderings.
The results show that formaldehyde enhances the durable press ratings and dimensional stability of the fabric through multiple home launderings. In addition, the treated fabric contained less than 200 ppm (parts per million) formaldehyde. Generally, the textile industry requires 500 ppm or less. Furthermore, when the compositions of this invention are compared with a conventional finishing bath containing 6.75 parts of dimethyloldihydroxyethyleneurea resin, equivalent durable press properties and dimensional stability characteristics are obtained with lower parts per million (ppm) of formaldehyde being present on the treated fabric.
TABLE I__________________________________________________________________________ Ratio For- maldehydeDimethylol- Formal- to Di- Magnesium Parts Perdihydroxy- Formal- dehyde Total hydroxy- Chloride- Fifth Millionethylene- dehyde added Formal- ethylene- Aluminum Dimensional Formalde-urea in (A) to (A) dehyde urea Chloride Zinc Fifth Wash Stability hyde on(A) (Parts) (B) (Parts) (C) (Parts) (B + C) (Parts) ##STR22## (9:1) (Parts) Nitrate (Parts) Water (Parts) Durable Press Rating WarpFill (Percent) treated fabric__________________________________________________________________________0.9 0.02 0.185 0.205 0.228 0.9 -- 98.00 3.5 -1.3 -0.6 1680.9 0.02 0.185 0.205 0.228 -- 1.5 97.40 3.5 -1.6 -0.5 48Comparison Examples-- -- -- -- -- -- -- 100.00 3 -2.8 -0.5 126.75 0.15 -- 0.15 0.022 0.9 -- 92.20 3.5 -1.3 -0.1 2750.9 0.02 -- 0.02 0.022 0.9 -- 98.18 3 -1.8 -0.6 76__________________________________________________________________________
EXAMPLE 2
Several compositions are prepared by dispersing the ingredients listed in Table II in water. These compositions are padded onto polyester/cotton (65/35) fabric at 50 percent wet pick-up. The fabric is dried and cured in accordance with the procedure described in Example I. The treated fabric is then evaluated for (a) parts per million formaldehyde; (b) dimensional stability after five home launderings; and (c) durable press properties after five home launderings.
The results show that the presence of formaldehyde in a durable press finish composition enhances the durable press ratings and dimensional stability of the fabric after multiple home launderings while remaining below 500 ppm of formaldehyde.
TABLE II__________________________________________________________________________ Alkylated Ratio Magnesium Parts Per2-Methoxy urea-For- Formalde- Total Formal- Chloride- Fifth Fifth Millioncarbamate maldehyde Formalde- hyde added Formal- dehyde Aluminum Wash Dimensional Formalde-resin resin hyde in (A) to (A) dehyde to resin Chloride Durable Stability hyde on(A) (Parts) (A) (Parts) (B) (Parts) (C) (Parts) (B + C) (Parts) ##STR23## (9:1) (Parts) Water (Parts) Press Rating WarpFill (Percent) treated fabric__________________________________________________________________________-- 0.96 0.018 0.185 0.203 0.211 0.9 97.94 3.5 -1.4 -0.3 3360.92 -- 0.030 0.185 0.215 0.234 0.9 97.96 3.5 -1.6 -0.5 66Comparison Examples-- -- -- -- -- -- -- 100.0 3.0 -2.8 -0.5 12-- 0.96 0.018 -- 0.018 0.019 0.9 98.12 3.5 -1.8 -0.6 1050.92 -- 0.030 -- 0.030 0.033 0.9 98.15 3.0 -1.8 -0.7 44__________________________________________________________________________
EXAMPLE 3
Several compositions are prepared by dispersing the ingredients listed in Table III in water. These compositions are padded onto polyester/cotton (65/35) fabric at 50 percent wet pick-up. The fabric is dried and cured in accordance with the procedure described in Example 1. The treated fabric is then evaluated for (a) parts per million residual formaldehyde; (b) dimensional stability after five home launderings; and (c) durable press properties after five home launderings.
The results show that aldehydes enhance the durable press ratings and dimensional stability of the fabric after multiple home launderings while the formaldehyde levels are acceptable to the textile industry. The comparison example shows that when the aminoplast resin is used alone at low levels, it gives inferior durable press ratings and only marginal dimensional stability. Generally, a durable press rating of 3.5 and a dimensional stability of less than 2 percent shrinkage for a 65/35 polyester/cotton fabric is acceptable to the textile industry.
TABLE III__________________________________________________________________________ Ratio Alde-Di- hyde to Di-methylol- Formal- Acetal- Pro- methylol- Magnesium Parts Perdihydroxy- Formal- dehyde dehyde pional- dihydroxy- Chloride- Fifth Fifth Millionethylene dehyde added added added Total ethylene- Aluminum Wash Dimensional Formal-urea in (A) to (A) to (A) to (A) Aldehyde urea Chloride Durable Stability dehyde on(A) (Parts) (B) (Parts) (C) (Parts) (C) (Parts) (C) (Parts) (B + C) (Parts) ##STR24## (9:1) (Parts) Water (Parts) Press Rating WarpFill (Percent) treated fabric__________________________________________________________________________0.9 0.02 0.185 -- -- 0.205 0.228 0.9 98.00 3.5 -1.4 -0.2 1010.9 0.02 0.244 -- -- 0.264 0.293 0.9 97.94 3.5 -1.4 -0.5 1060.9 0.02 -- 0.185 -- 0.205 0.228 0.9 98.00 3.5 -1.5 -0.5 590.9 0.02 -- -- 0.194 0.214 0.238 0.9 97.99 3.5 -1.8 -0.5 215Comparison Examples-- -- -- -- -- -- -- -- 100.00 3.0 -2.8 -0.5 120.9 0.02 -- -- -- 0.020 0.022 0.9 98.18 3.0 -1.8 -0.6 76__________________________________________________________________________
EXAMPLE 4
Several bath compositions are prepared by dispersing the ingredients listed in Table IV in a water-ethanol solvent. These formulations are padded onto polyester/cotton (65/35) fabric at a 30 percent wet pick-up. The fabric is dried and cured in accordance with the procedure described in Example 1. The treated fabric is then evaluated for (a) parts per million formaldehyde; (b) dimensional stability after five home launderings; and (c) durable press properties after five home launderings.
The results show that the presence of an aromatic aldehyde in a water-ethanol solvent system will improve the durable press ratings and dimensional stability of the fabric after multiple home launderings. Also, the data indicates that the dimethyloldihydroxyethyleneurea contributes to the increased formaldehyde level.
TABLE IV__________________________________________________________________________ Ratio Alde- hyde to Di-Dimethylol- Salicyl- methylol- Magnesium Parts Perdihydroxy- Formal- aldehyde dihydroxy Chloride- Fifth Millionethylene dehyde added Total ethylene Aluminum Fifth Wash Dimensional Formalde-urea in (A) to (A) Aldehyde urea Chloride Durable Stability hyde on(A) (Parts) (B) (Parts) (C) (Parts) (B + C) (Parts) ##STR25## (9:1) (Parts) Water (Parts) Ethanol (Parts) Press Rating WarpFill (Percent) treated fabric__________________________________________________________________________0.9 0.02 0.185 0.205 0.228 0.9 3.80 94.2 3.5 -1.85 -0.3 132Comparison Examples-- -- -- -- -- -- 100.00 -- 3.0 -2.8 -0.5 12-- -- -- -- -- -- 5.5 94.5 3.0 -2.8 -0.5 50.9 0.02 -- 0.02 0.022 0.9 3.68 94.5 3.0 -1.9 -0.1 129__________________________________________________________________________
EXAMPLE 5
Several compositions are prepared by dispersing the ingredients of Table V in water. These compositions are padded onto 100 percent cotton at a 50 percent wet pick-up. The fabric is dried and cured in accordance with the procedure described in Example 1. The treated fabric is then evaluated for (a) parts per million formaldehyde; (b) dimensional stability after five home launderings; and (c) durable press properties after five home launderings.
The results show that a durable press composition containing formaldehyde and dimethyloldihydroxyethyleneurea substantially improves the dimensional stability and durable press properties of 100 percent cotton as compared with a durable press composition containing only dimethyloldihydroxyethyleneurea.
TABLE V__________________________________________________________________________ Ratio For- maldehyde toDimethylol- Dimethyloldi- Magnesium Parts Perdihydroxy- Formal- Formalde- Total hydroxy Chloride- Fifth Wash Millionethylene dehyde hyde added Formalde- ethyleneurea Aluminum Dimensional Formal-urea (A) (Parts) in (A) (B) (Parts) to (A) (C) (Parts) hyde (B + C) (Parts) ##STR26## Chloride (9:1) (Parts) Water (Parts) Fifth Wash Durable Press Stability WarpFill (Percent) dehyde on treated fabric__________________________________________________________________________1.80 0.04 0.185 0.225 0.125 1.2 96.78 2 -1.8 +0.4 2472.25 0.05 0.092 0.142 0.063 1.2 96.41 2 -1.85 +0.4 1922.25 0.05 0.185 0.235 0.104 1.2 96.32 2 -1.6 +0.1 374Comparison Examples-- -- -- -- -- -- 100.0 1 -6.45 +0.35 41.80 0.04 -- 0.04 0.022 1.2 96.96 2 -2.0 +0.25 1032.25 0.05 -- 0.05 0.022 1.2 96.54 2 -2.0 +0.2 357__________________________________________________________________________
EXAMPLE 6
Several compositions are prepared by dispersing the ingredients listed in Table VI in water. These compositions are padded onto polyester/cotton (65/35) fabric at 50 percent wet pick-up. The fabric is dried and cured in accordance with the procedure described in Example 1. The treated fabric is then evaluated for (a) parts per million formaldehyde; (b) dimensional stability after five home launderings; (c) durable press properties after five home launderings; and (d) fabric hand.
The results show that the presence of formaldehyde in a durable press finishing composition containing dimethyloldihydroxyethyleneurea improves the durable press ratings and dimensional stability of the fabric after multiple home launderings while the formaldehyde level is less than 300 ppm. In addition, the presence of the softener has no effect on the amount of formaldehyde present on the fabric, nor the durable press properties and dimensional stability characteristics of the fabric after multiple launderings. Furthermore, all fabrics treated with softeners have a soft, silky hand. The results are shown in Table VI.
The softeners employed in Examples 6(a) to (e) are prepared in the following manner:
(a) A 33 percent aqueous emulsion of a softener is prepared by heating a mixture containing 124 parts of succinic anhydride and 2,278 parts of oxyethylene-oxypropylene triol copolymer, having a molecular weight of 6360 and a weight ratio of oxyethylene to oxypropylene of 7 to 3 at 120° C. for eighteen hours in a reaction vessel. The resultant product is a yellow liquid having a viscosity of 4,168 cs. at 25° C. and an acid content of 0.58 milliequivalents per gram (theoretical 0.5 me/g).
The resultant product is mixed with 238 parts by weight of aminopropyltriethoxysilane at 70° C. for 3.0 hours. This reaction product is a yellow liquid having a viscosity of about 30,000 cs. at 25° C. The reaction product is mixed with 660 parts by weight of hydroxy terminated polydimethylsiloxane at 50° C. for 6 hours. The resultant product is a white, opaque fluid having a viscosity of 1,500,000 cs. at 25° C. The product is then combined with 6,700 parts by weight of water. A white, opaque emulsion having a viscosity of 50 cs. at 25° C. is obtained.
(b) An aqueous emulsion consisting of 16 percent of the polymer prepared in (a) and 25 percent of a polysiloxane represented by the formula ##STR27##
(c) A 33 percent aqueous solution of a polymer is prepared by heating a mixture containing 150 parts of succinic anhydride and 2880 parts of oxyethylene-oxypropylene triol copolymer, having a molecular weight of 6360 and a weight ratio of oxyethylene to oxypropylene of 7 to 3, for eighteen hours at 120° C. The product is a yellow liquid having a viscosity of 4,168 mPa.s at 25° C., and an acid content of 0.58 milliequivalents per gram (theoretical 0.5 me/q).
The resultant product is then mixed with 300 parts of aminopropyltriethoxysilane and heated at 70° C. for 2 hours. The product is a yellow liquid having a viscosity of about 30,000 mPa.s at 25° C. The resultant product is then mixed with 6670 parts of water to form a clear, straw-colored solution having a viscosity of 50 mPa.s at 25° C.
(d) A 25 percent active aqueous emulsion of a fatty acid condensation product. (Ceranine HCA--available from Sandoz Colors and Chemicals).
(e) A 33 percent aqueous solution of a polymer is prepared by heating a mixture containing 124 parts of succinic anhydride, 930 parts of oxyethylene diol having a molecular weight of 1500 at 120° C. for eighteen hours in a reaction vessel. The resultant product is a yellow liquid having an acid content of 1.2 milliequivalents per gram.
The resultant product is mixed with 374 parts of aminopropyltriethoxysilane at 70° C. for 3.0 hours. The reaction product is then mixed with 2702 parts of water. A clear, strawcolored solution is obtained.
TABLE VI__________________________________________________________________________ Ratio For- maldehyde to Di- Dimethyl- Formal- methylol- Magnesium Part Per oldihy- Formal- dehyde Total dihydroxy- Chloride- Fifth Wash Million droxy- dehyde added Formal- ethyl- Aluminum Fifth Wash Dimensional Formal-Softener ethylene- in (A) to (A) dehyde eneurea Chloride Durable Stability dehydeExample 6(Parts) urea (A) (Parts) (B) (Parts) (C) (Parts) (B + C) (Parts) ##STR28## (9:1) (Parts) Water (Parts) Press Rating WarpFill (Percent) on treated__________________________________________________________________________ fabric(a) 0.99 0.9 0.02 0.185 0.205 0.228 0.9 97.00 3.5 -1.5 -0.4 88(b) 0.96 0.9 0.02 0.185 0.205 0.228 0.9 97.04 3.5 - 1.4 -0.3 85(c) 0.99 0.9 0.02 0.185 0.205 0.228 0.9 97.00 3.5 -1.8 -0.6 294(d) 1.17 0.9 0.02 0.185 0.205 0.228 0.9 96.82 3.5 -1.4 -0.3 201(a) 6.01 0.9 0.02 0.185 0.205 0.228 0.9 91.98 3.5 -1.6 -0.4 277(e) 0.82 0.9 0.02 0.185 0.205 0.228 0.9 97.18 3.5 -1.5 -0.5 150Comparison Examples-- -- -- -- -- -- -- -- 100.00 3.0 -2.8 -0.5 12-- -- 0.9 0.02 -- 0.02 0.022 0.9 98.18 3.0 -1.8 -0.6 76(a) 0.99 0.9 0.02 -- 0.02 0.022 0.9 97.19 3.0 -1.9 -0.55 79-- -- 0.9 0.02 0.185 0.205 0.228 0.9 98.00 3.5 -1.3 -0.6 168__________________________________________________________________________
EXAMPLE 7
Several compositions are prepared by dispersing the ingredients shown in Table VII in water. The softener is prepared in accordance with the procedure described in Example 6(a). These compositions are padded onto samples of polyester/cotton (65/35) fabric at a 50 percent wet pick-up. The fabric is dried and cured in accordance with the procedure described in Example 1. The treated fabric is then evaluated for (a) parts per million formaldehyde; (b) dimensional stability after five home launderings; (c) durable press properties after five home launderings; and (d) fabric hand. The results of these evaluations indicate that the presence of formaldehyde in a finishing bath containing varying levels of dimethyloldihydroxyethyleneurea enhance the durable press ratings and dimensional stability of the fabric after multiple home launderings while having less than 300 parts per million of formaldehyde. In addition, the presence of softener has no effect on the amount of formaldehyde present on the fabric nor the durable press ratings and dimensional stability characteristics of the fabric after multiple launderings. Furthermore, all fabrics treated with softeners have a soft, silky hand. The results are shown in Table VII.
TABLE VII__________________________________________________________________________ Ratio For- maldehyde to Di- Dimethyl- Formal- methylol- Magnesium Part Per oldihy- Formal- dehyde Total dihydroxy- Chloride- Fifth Wash Million droxy- dehyde added Formal- ethyl- Aluminum Fifth Wash Dimensional Formal-Softener ethylene- in (A) to (A) dehyde eneurea Chloride Durable Stability dehydeExample 6(a) (Parts) urea (A) (Parts) (B) (Parts) (C) (Parts) (B + C) (Parts) ##STR29## (9:1) (Parts) Water (Parts) Press Rating WarpFill (Percent) on treated__________________________________________________________________________ fabric0.99 0.9 0.02 0.185 0.205 0.228 0.9 97.00 3.5 -1.5 -0.44 880.99 2.25 0.05 0.185 0.235 0.104 0.9 95.62 3.5 -1.2 -0.2 218Comparison Examples-- -- -- -- -- -- -- 100.00 3.0 -2.8 -0.5 12-- 0.9 0.02 -- 0.02 0.022 0.9 98.18 3.0 -1.8 -0.6 76-- 0.9 0.02 0.185 0.205 0.228 0.9 98.00 3.5 -1.3 -0.6 1680.99 0.9 0.02 -- 0.02 0.022 0.9 97.19 3.0 -1.9 -0.55 79-- 2.25 0.05 -- 0.05 0.022 0.9 96.80 3.5 -1.55 -0.4 177-- 2.28 0.05 0.185 0.235 0.104 0.9 96.62 3.5 -1.05 -0.25 2960.99 2.25 0.05 -- 0.05 0.022 0.9 95.81 3.5 -1.45 -0.55 156__________________________________________________________________________
EXAMPLE 8
Several compositions are prepared by dispersing the ingredients listed in Table VIII in water. The softener is prepared in accordance with the procedure described in Example 6(a). These formulations are padded onto samples of polyester/cotton (65/35) fabric at 50 percent wet pick-up. The fabric is dried and cured in accordance with the procedure described in Example 1. The treated fabric is then evaluated for (a) parts per million formaldehyde; (b) dimensional stability after five home launderings; (c) durable press properties after five home launderings; and (d) fabric hand. The results of these evaluations show that the presence of an aldehyde in the formulation can enhance the durable press ratings and dimensional stability of the fabric after multiple home launderings while having formaldehyde levels which are acceptable by the textile industry. Furthermore, all fabrics treated with softeners have a soft, silky hand. The results are shown in Table VIII.
TABLE VIII__________________________________________________________________________ Ratio Alde- hyde to Di- Dimethyl- Formal- Acetal- methylol- Magnesium Parts PerSoften- oldihydrox- Formal- dehyde dehyde Total dihydroxy- Chloride- Fifth Fifth Millioner Ex- yethylene- dehyde added added Alde- ethylene- Aluminum Wash Dimensional Formalde-ample urea in (A) to (A) to (A) hyde urea Chloride Durable Stability hyde on6(a) (Parts) (A) (Parts) (B) (Parts) (C) (Parts) (C) (Parts) (B + C) (Parts) ##STR30## 9:1 (Parts) Water (Parts) Press Rating WarpFill (Percent) treated fabric__________________________________________________________________________0.99 0.9 0.02 0.185 -- 0.205 0.228 0.9 97.00 3.5 -1.5 -0.4 880.99 0.9 0.02 0.418 -- 0.438 0.487 0.9 96.77 3.5 -1.25 -0.2 2830.99 0.9 0.02 -- 0.185 0.205 0.228 0.9 97.00 3.5 -1.5 -0.4 541.32 0.9 0.02 -- 0.244 0.264 0.293 0.9 96.62 3.5 -1.7 -0.4 35Comparison Examples-- -- -- -- -- -- -- -- 100.0 3.0 -2.8 -0.5 12-- 0.9 0.02 -- -- 0.02 0.022 0.9 98.18 3.0 -1.8 -0.6 76__________________________________________________________________________
EXAMPLE 9
Several compositions are prepared by dispersing the ingredients listed in Table IX in water. The softener is prepared in accordance with the procedure in Example 6(a). These formulations are padded onto polyester/cotton (65/35) fabric at 50 percent wet pick-up. The fabric is dried and cured according to the procedure in Example 1. The treated fabric is then evaluated for (a) parts per million formaldehyde; (b) dimensional stability after five home launderings; (c) durable press properties after five home launderings; and (d) fabric hand. The results of these evaluations show that the presence of formaldehyde in the formulation enhances the durable press ratings and dimensional stability of the fabric after multiple launderings while the fabric contains less than 250 parts per million of formaldehyde. In addition, all fabrics treated with softeners have a soft, silky hand. Furthermore, variation of the amount of acid catalyst present in the formulation has no effect on either of the above results. The results are shown in Table IX.
TABLE IX__________________________________________________________________________ Ratio For- maldehyde to Di-Dimethyl- Formal- methylol- Magnesium Part Perdihy- Formal- dehyde Total dihydroxy- Chloride- Fifth Wash MillionSoftenerdroxy- dehyde added Formal- ethyl- Aluminum Fifth Wash Dimensional Formal-Exampleethylene- in (A) to (A) dehyde eneurea Chloride Durable Stability dehyde6(a) (Parts)urea (A) (Parts) (B) (Parts) (C) (Parts) (B + C) (Parts) ##STR31## (9:1) (Parts) Water (Parts) Press Rating WarpFill (Percent) on treated__________________________________________________________________________ fabric0.99 0.9 0.02 0.185 0.205 0.228 0.9 97.00 3.5 -1.5 -0.4 880.99 0.9 0.02 0.185 0.205 0.228 1.5 96.40 3.5 -1.55 -0.35 2330.99 0.9 0.02 0.185 0.205 0.228 3.0 94.90 3.5 -1.5 -0.20 143Comparison Examples-- -- -- -- -- -- -- 100.0 3 -2.8 -0.5 12-- 0.9 0.02 -- 0.02 0.022 0.9 98.18 3 -1.8 -0.6 76__________________________________________________________________________
EXAMPLE 10
Several compositions are prepared by dispersing the ingredients shown in Table X in water. The softener is prepared in accordance with the procedure described in Example 6(a). These compositions are padded onto 100 percent cotton at 50 percent wet pick-up. The fabric is dried and cured in accordance with the procedure described in Example 1. The treated fabric is then evaluated for (a) parts per million formaldehyde; (b) dimensional stability after five home launderings; (c) durable press properties after five home launderings; and (d) fabric hand. The results show that the presence of formaldehyde in a textile finishing composition containing a softener improves dimensional stability and durable press properties of cotton in comparison to that obtained with a composition containing only dimethyldihydroxyethylene urea and a softener. Furthermore, the treated fabric had a soft, silky hand. The results are shown in Table X.
TABLE X__________________________________________________________________________ Ratio For- maldehyde to Di-Dimethyl- Formal- methylol- Magnesium Part Peroldihy- Formal- dehyde Total dihydroxy- Chloride- Fifth Wash MillionSoftenerdroxy- dehyde added Formal- ethyl- Aluminum Fifth Wash Dimensional Formal-Exampleethylene- in (A) to (A) dehyde eneurea Chloride Durable Stability dehyde6(a) (Parts)urea (A) (Parts) (B) (Parts) (C) (Parts) (B + C) (Parts) ##STR32## (9:1) (Parts) Water (Parts) Press Rating WarpFill (Percent) on treated__________________________________________________________________________ fabric0.99 1.80 0.04 0.185 0.225 0.185 1.2 95.78 2 -1.8 +0.6 2020.99 2.25 0.05 0.185 0.235 0.104 1.2 95.32 2 -1.6 +0.1 4840.99 2.25 0.05 0.092 0.142 0.063 1.2 95.42 2 -1.75 +0.3 146Comparison Examples-- -- -- -- -- -- -- 100.00 1 -6.45 +0.35 4-- 1.80 0.04 -- 0.04 0.022 1.2 96.96 2 -2.0 +0.25 103-- 1.80 0.04 0.185 0.225 0.125 1.2 96.78 2 -1.8 +0.4 247-- 2.25 0.05 -- 0.05 0.022 1.2 96.50 2 -2.0 -0.2 357-- 2.25 0.05 0.185 0.235 0.104 1.2 96.32 2 -1.8 0 374-- 2.25 0.05 0.092 0.142 0.063 1.2 96.41 2 -1.85 +0.4 192__________________________________________________________________________
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A textile finishing composition comprising (1) a diluent and (2) a durable press resin composition containing (a) an aminoplast resin and (b) an aldehyde. The textile finishing composition is combined with an acid catalyst and applied to textile materials to impart softness, improved wetting properties and durable press properties.
The textile finishing composition is applied at lower than normal dry add-on levels to textile materials to provide textile materials having lower levels of formaldehyde.
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BACKGROUND OF THE INVENTION
Fires in high-rise, multiple dwelling structures, such as apartment buildings, hotels, motels and office buildings, are a serious source of concern to people who either live in or temporarily reside in such premises. Fires with the resultant intense smoke and fume generation are particularly devasting in high-rise structures in which a large number of people may be entrapped. Furthermore, by their very nature, high-rise structures present physical impediments to rapid rescue attempts, particularly with regard to persons who may be entrapped on the upper levels of such structures. Accordingly, the time elapsing between the initial outbreak of a fire and the arrival of the rescue team at a room on an upper floor may be relatively great.
Most fire-related deaths are not caused by the fire directly, but result from the toxic fumes and smoke generated by the fire. A common procedure for entrapped persons, whose escape has been blocked or the route is unknown, is to await rescue by isolating themselves as much as possible from the fumes and smoke of the fire. This isolation is generally attempted by huddling within a small room (e.g., the bathroom) with the door closed, and for example, by placing wet materials against the bottom of the door and the floor to prevent fumes and smoke from entering. The difficulty resulting from this procedure is that there is only a limited amount of breathable air within the isolated room, and there may be no means for providing fresh air. (For example, there may be no windows in the bathroom or the smoke rising around the building from lower floors may dictate that the bathroom window must remain closed). In spite of the barricading efforts by those who are trapped, smoke and fumes quickly begin seeping into the place of refuge, and thus asphyxiation or smoke poisoning may soon result unless rescuers arrive almost immediately.
Existing fire protection systems do not attempt to solve the above problem. For example, the object of sprinkler systems is to put out the fire, but such systems do not provide fresh air to entrapped persons.
It has also been proposed (Letter to the Editor, New York Times, Feb. 14, 1981, Charles F. Sepsy) to "modify a building's heating and cooling system so that air can be pumped into the area adjacent to the fire" so that "an invisible curtain can be placed around the flames, and smoke as well as gases can be exhausted to the outdoors". Apart from the fact that this proposed system would appear to require a very complicated system of baffles and zones to prevent inadvertent force feeding of oxygen to the fire, its purpose is to isolate the fire to allow entrapped occupants time to escape. This proposed system does not provide fresh air to those unable to escape before rescuers arrive. Furthermore, the large ducts which are characteristic of existing heating and cooling systems tend to serve as channels for conducting hot smoke and fumes into the rooms on the upper floors. Thus, occupants trapped in a bathroom on an upper floor would likely be forced to block the mouth of any air conditioning or heating duct which opened into the bathroom for preventing overheated air, smoke and fumes from flooding into their place of refuge.
It is an object of the present invention to provide a reliable and relatively simple system advantageously utilizing existing small-diameter hot and cold water feed pipes in a building to provide fresh air to occupants entrapped within predetermined rooms of refuge in the building to sustain life and to aid in excluding smoke and fumes from the isolated room until rescuers arrive.
SUMMARY OF THE INVENTION
The present invention provides a method and system for providing fresh air to occupants entrapped within a burning building. The system advantageously utilizes existing hot and cold water supply lines to jet pressurized air to individual predetermined refuge rooms in the respective occupancy units within the premises. Such refuge rooms are usually the bathrooms. The occupants, upon finding themselves trapped, retreat into the predetermined room and take steps to exclude the entry of smoke, fumes or overheated air, usually placing wet towels or wet blankets or drapes against the inside of the door. Pressurized air is fed through the small-diameter water pipes into the refuge room, thereby advantageously raising the pressure within this shelter for aiding in excluding noxious gases and overheated air while replenishing the life-sustaining breathable air in the room. Thus, the occupants are bathed in a life-sustaining, smoke-excluding atmosphere of slightly elevated pressure, until the rescue team can arrive.
In the system as shown there is a source of compressed air and actuator means for automatically commencing the flow from this source. The actuator is connected to a plurality of fire sensors located in the different occupancy units within the building. Upon detection of a fire, the source of pressurized air is actuated to supply such air through the water supply pipes. The pressure of the compressed air is greater than that of the water in either the hot or cold supply line, and as such, there is insignificant water flow through the lines while the compressed air is being jetted through these lines. The system advantageously uses check valves and pressure-sensitive valves to interconnect the hot and cold water supply lines, yet prevents mixing of the hot and cold water. In this manner, compressed air can be provided through both the hot and cold water lines simultaneously via a pipeline from the compressed air source interconnecting the main hot and cold water supply lines.
Pressure-responsive release valves are connected to the hot and cold water lines in the respective bathrooms. These release valves automatically allow the pressurized air to enter the respective rooms of refuge in case the occupants are panicked and forget or do not realize that the hot and cold faucets should be opened to admit breathable pressurized air into their isolated room.
BRIEF DESCRIPTION OF THE DRAWING
The drawing illustrates an elevational sectional view of a high-rise building structure incorporating one embodiment of a system in accordance with the present invention for providing pressurized breathable air to trapped fire victims using existing hot and cold water feed pipes in the existing structure for feeding the pressurized air to the respect rooms of refuge.
DETAILED DESCRIPTION
The drawing illustrates an elevational view, in section, of a high-rise building structure 2, which may be, for example, an apartment house, a motel, a hotel, office building, or the like. For illustrative purposes, three levels or stories of the building are shown by reference numerals 4, 6 and 8. On each level of the building, there are shown two occupancy units i.e., suites or apartments or offices, having bathrooms illustrated by the numbers 10, 12, 14, 16, 18 and 20, respectively. The occupancy units in existing buildings are often arranged so that the bathrooms share a common vertical wall space 21 containing common main hot and cold water feed pipes, 22 and 24, respectively, sometimes called risers, which run up through the common wall 21 separating the occupancy units on each level of the building.
In this embodiment of the invention the predetermined refuge rooms are the bathrooms 10, 12, 14, 16, 18 and 20. Hot and cold water pipes 28 and 30, respectively, branch out from their respective main feed pipes 22 and 24 into the bathroom of each apartment. In the drawing, the pipes 28 and 30 are shown connected to sinks 32 in each bathroom. Each sink has a hot water faucet 34 and a cold water faucet 36.
Water is supplied into the building to the feed lines 22 and 24 from a trunk or main supply inlet line 38. When water is used, the water pressure forces the water past a manually operated main shut-off valve 40 and through a meter 42. A pipe 44 leading to water heating means 46, for example, a water heater, connects with the main supply line 38, so that a portion of the water initially flowing into the supply line 38 may flow through pipe 44 and into the water heater. Water is also fed from the trunk line 38, past a check valve 48, and directly into the cold water feed pipe 24. Water flowing from the water heater 46 flows out an outlet pipe 50 coupled to the water heater, past a check valve 52, and directly into the hot water feed line 22. Shut-off valves 54 and 56, disposed in the inlet pipe 44 and in the outlet pipe 50 leading into and out of the water heater 46, are provided to manually cut off water flow through the heater in case of need to provide maintenance or otherwise service the water heater 46.
A plurality of fire sensors or detectors 58 are positioned throughout the building 2 in the respective occupancy units. For illustrative purposes, each of the occupancy units includes at least one fire detector 58 mounted in a room adjacent to the bathroom in that occupancy unit. Such fire detectors 58 are commercially available and several different types of those detectors are known. Generally speaking, a fire detector or sensor is a device which provide an electrical signal in response to either a threshold level of smoke or ionized particles in its immediate proximity or a threshold level of temperature. The electrical signal actuates alarm means to indicate to occupants the existence of a fire.
In the present embodiment of the invention, the fire detectors 58 in addition to being connected to alarm means (not shown) are electrically coupled to a valve actuator 60 and an air compressor 62. Specifically, each fire detector is connected by wires 64 and 66 to a main control circuit including wires 68 and 70. This control circuit is connected to both the valve actuator and to the air compressor. When one of the detectors 58 provide a signal over the control circuit 68, 70, the valve actuator 60 opens an air valve 76 and the compressor 62 is automatically started. This compressor 62 may be driven by a gasoline or diesel engine. This compressor 62 includes an electrical starter motor and storage batteries for energizing the starter motor. These batteries are always maintained fully charged by a trickle charger, as is known in the storage battery art, so that the compressor is ready to be automatically started at any moment.
An air line 72 connects the compressor 62 to a large compressed air receiver storage tank 74. This storage tank 74 is relatively large and is maintained fully loaded with compressed air at an elevated pressure, for example at a predetermined pressure level in the range from 100 to 300 pounds per square inch (p.s.i.) as indicated by a pressure gage 75. The size of this tank 74 and its pressure gage 75 are sufficient to maintain the compressed air flow through the lines 22 and 24 to the trapped occupants until the compressor 62 has been started and is running at its full rated output. The air line extends from the storage tank 74, through the shut-off valve 76 and through a pressure regulator 77 and through a check valve 78, and intersects with the cold water feed pipe 24 at a connection point designated by numeral 80, and then this air line 72 extends through a pressure-responsive valve 82, and a check valve 84, after which it connects with the main hot water feed pipe 22 at a point designated by numeral 86.
It is to be understood that the compressor 62, the storage tank 74 and the actuator controlled valve 76 and associated components 77 and 78 are housed in a separate or protected location relative to the building structure 2. This separate, protected location may be above or below ground, whichever is more practicable in a particular instance. Thus, any fire in the building 2 cannot affect this source 83 of compressed air. The air control valve 76 has a handle 85 so that it can be turned open manually, if manual actuation should be desired for any reason. The pressure regulator 77 is set at a predetermined level approximately 15 to 35 p.s.i. above the water pressure as shown by a gage 87 connected to the water supply main 38. The exact pressure at which the regulator 77 is set is not critical, except that it should exceed the water pressure 87 by a significant amount so that the water is quickly purged out of the risers 22 and 24 after the air control valve 76 has been opened.
If desired a smaller auxiliary compressor may be provided for maintaining the tank 74 fully charged in spite of any minor leakage.
This auxiliary compressor is associated with a control which continually monitors the pressure in the tank 74 and automatically operates the auxiliary compressor from time to time for maintaining air pressure in tank 74 at the desired pressure level.
Before discussing the operation of the above-described system, it is to be noted that the hot and cold water pipes connected to each sink each include a conventional shut-off valve 88 and also include a pressure-responsive discharge valve 90. The shut-off valve 88 is normally in its open position and is provided for the purpose of manually shutting off the flow of water to the sink faucets during maintenance or repair operations. Likewise, the shut-off valves 40, 54 and 56 are normally in open position to permit water flow therethrough. Valve 76 is normally in a closed position so that compressed air is not introduced into the water supply system during normal operation of the building 2.
In operation of this life-sustaining method and system, a fire in the building 2 will actuate one of the fire detectors 58 which is closest to or most quickly affected by the fire. Actuation of any of the fire detectors 58 causes transmission of an electrical signal through the wires 64 and 66 of the actuated fire detector, and through the control circuit 68 and 70 which are electrically connected to both the air compressor 62 and the valve actuator 60. The electrical signal starts the air compressor running and simultaneously opens the valve 76 to permit pressurized air flow therethrough. The result is that air from the compressed air storage tank flows through the air pipe 72 and through the now open valve 76. Check valve 78 permits air flow in a direction towards the hot and cold water feed pipes 22 and 24, but prevents water from reaching the pressure regulator 77.
When the compressed air reaches the connection point 80 at which pipe 72 intersects the cold water feed pipe 24, a portion of the compressed air forces itself upwardly through the cold water feed pipe 22 as a result of its pressure level as set by the regulator 77. The air pressure is greater than that of the water pressure of the cold water from the trunk line 38, so that cold water is now prevented from travelling through the cold water supply line 38 beyond the check valve 48. The pressure of the air flowing up the cold water feed pipe 24 drives the existing water in that pipe ahead of the air, to effectively eject such water from that pipe through the various pressure-responsive discharge valves 90. These discharge valves 90 may be similar in construction to pressure-relief valves, except that they contain spring biased latches for holding them open, until manually returned to closed position. They are set at a pressure level above the normal pressure of the water in the feed pipes 22 and 24, but they are set at a level below the level of the pressure regulator 77. Thus, these discharge valves 90 normally remain closed. However, when the pressurized air surges up through the line 24 these discharge valves 90 become opened in response to the increased pressure resulting from the pressurized air flow through the water pipes, and they remain open until manually turned off.
The compressed air not travelling up the cold water feed pipe 24 continues to flow through the air pipe 72 towards the hot water feed line 22. The pressure of the compressed air is sufficient to open the pressure-sensitive valve 82, and the check valve 84 permits such air to continue to flow towards the hot water feed pipe 22. The compressed air cannot flow from the air pipe 72 into the outlet pipe 50 and towards the water heater 40, because the other check valve 52 prevents fluid flow in that direction. Accordingly, the compressed air flowing from the air pipe 72 at the connection point 86 must flow into the hot water feed pipe 22.
It is noted that the pressure-sensitive valve 82 normally remains closed, because it is set at a pressure level above the normal pressure level of the water in the hot and cold water pipes. Thus, the cold water cannot normally pass through the valve 82 and mix with the hot water. The check valve 84 in turn prevents the hot water from mixing with the cold water. Therefore, the cold water and hot water are normally isolated from each other. This pressure-sensitive valve 82 is set at a pressure level above the normal pressure of the water in the cold water line 24 and below the pressure of the pressure regulator 77. Thus, the increase in pressure resulting from the entry of pressurized air into the line 72 opens the valve 82. This valve 82 is constructed like a pressure-relief valve with a spring-biased latch which keeps the valve 82 open until the valve is manually reset. This valve 82 opens when the pressure in the line 72 between the connection 80 and the valve 82 exceeds its pre-set level and thereafter it remains open until manually reset.
As described previously, the pressurized air entering the connection 86 cannot flow through the check valve 52. This pressurized air is at a pressure greater than the pressure of the hot water normally flowing from outlet pipe 50. Accordingly, in a manner similar to that discussed above with respect to the cold water pipe, the pressure of the compressed air prevents the flow of the lower pressure hot water past the check valve 52. The air quickly drives the hot water out of the feed pipe 22 through the various discharge valves.
In summary of the above discussion, soon after the pressurized air is started flowing by the valve 76, the cold and hot water feed lines 24 and 22 are purged of their water content and pressurized air begins flowing into the bathrooms 10, 12, 14, 16, 18, 20 which can thereby serve as rooms of refuge for trapped occupants.
When the compressor is actuated, compressed air flowing through the pipes 22 and 24, as discussed above, flows into the individual feed or branch pipes 28 and 30 in each of the bathrooms 10, 12, 14, 16, 18 and 20 of the illustrated occupancy units. Preferably, the faucets 34 and 36 on any sink in a bathroom containing one or more trapped occupants will quickly be opened by the occupants so that the pressurized air can freely flow into the respective bathroom. In this respect, a sign may be provided above each sink instructing the occupants to close the bathroom door and to open the faucets in the event of fire. In any event, the pressure-sensitive discharge valves 90 mounted in the pipes 28 and 30 of each sink 32 are set so that the pressure of the compressed air is sufficient to automatically open these valves. Consequently, pressurized air will flow out the valves 90 even if the faucets on the sink are not opened. In this manner, trapped occupants awaiting rescue will be provided with sufficient air to sustain life and to aid in excluding smoke or noxious fumes or heated air from the bathroom until the arrival of rescuers.
Another advantage of the pressurized air is that upon its release through the faucets 34, 36 and/or its release through the discharge valves 90, the air immediately expands in volume while its pressure drops. Therefore, even though it is being supplied through relatively small-diameter water pipes, it will constitute a significant volume of breathable air flowing into each room of refuge during each second of time as it expands upon entry into the room. Furthermore, the sudden expansion of the compressed air will inherently cause its temperature to decrease, which will provide a welcome cooling effect for the trapped occupants.
Once there is assurance that all of the occupants have been removed from the building, the flow of compressed air may be terminated by deactuating the compressor 62 and closing the valve 76 at the outlet of the air storage tank 74. These operations are performed manually.
The embodiment of the invention as described above is a method and system which advantageously uses existing small-diameter water pipes in a building to provide an emergency air supply system for occupants trapped in a fire. The system itself may be constructed as part of a new building, or may be retrofitted into an existing building. The system uses relatively few components and thus can be quickly and relatively economically installed.
As used herein the term "small-diameter pipes" or "small-diameter piping" is intended to mean the size of piping conventionally used to feed water to the various occupancy units in a building in distinction to the large diameter ducts which would be required to feed conditioned air from a central air conditioning and heating installation to the same occupancy units in that building. As the number of occupancy units in the building is increased, the diameter of the water feed lines is increased to accommodate the increased demand. By the same token, the air conditioning ducts would also be increased in cross-sectional area. Therefore, the water piping is still considered to be "small-diameter piping", because it is small relative to the size of the ducts which would be required to carry conditioned air from a central air conditioning and heating installation to all of the various occupancy units.
The embodiment of the invention discussed above is intended to be illustrative only, and not restrictive of the scope of the invention, that scope being defined by the following claims and all equivalents thereto.
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The present invention provides a method and system for providing air to persons entrapped within a burning structure to sustain life until rescuers arrive. The system advantageously utilizes existing water pipes to feed the air at elevated pressure to the trapped occupants. These persons, upon finding their route of escape blocked by the fire or by smoke, retreat into a predetermined refuge room, a bathroom usually or a washroom, and place wet towels, curtains, blankets, etc. against the door to aid in excluding smoke. The pressurized air being supplied through the pipes into the refuge room advantageously raises the pressure therein and thereby prevents the entry of undue amounts of smoke while at the same time replenishing the breathable air within the room.
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RELATED APPLICATIONS
Benefit is claimed under 35 U.S.C. 119(e) to U.S. Provisional Application Ser. No. 60/700,200, entitled “Field Generation without Magnetic Material for Electronic Stripe” by Narendra et al., filed Jul. 18, 2005, which is herein incorporated in its entirety by reference for all purposes.
Benefit is also claimed under 35 U.S.C. 119(e) to U.S. Provisional Application Ser. No. 60/700,089, entitled “Swipe Sensor for Electronic Stripe Energy Reduction” by Narendra et al., filed Jul. 18, 2005, which is herein incorporated in its entirety by reference for all purposes.
Benefit is also claimed under 35 U.S.C. 119(e) to U.S. Provisional Application Ser. No. 60/700,248, entitled “Interleaved Track Driving” by Narendra et al., filed Jul. 18, 2005, which is herein incorporated in its entirety by reference for all purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 show prior art magnetic field generation;
FIGS. 3 and 4 show diagrams of electronic stripe cards in accordance with various embodiments of the present invention;
FIGS. 5-8 show magnetic field generation in accordance with various embodiments of the present invention;
FIG. 9 shows swipe sensor contacts and a read head in relation to an electronic stripe card;
FIG. 10 shows a plot of swipe sensor impedance; and
FIG. 11 shows a diagram of an electronic stripe card in accordance with various embodiments of the present invention.
FIELD
The present invention relates generally to magnetic field generation, and more specifically to magnetic field generation in cards.
BACKGROUND
As shown in FIGS. 1 and 2 , in the prior art, a coil around a magnetic material is used to generate magnetic field that “adds” up inside the magnetic material by using the same biasing current. The direction of flow of current in the top layer is opposite in the z-axis to that of the bottom layer, but the field lines below the top metal layer and above the bottom metal layer are confined in the magnetic field and will be along the same direction.
SUMMARY
In one embodiment, the invention includes an electronic stripe having a top metal layer without magnetic material therebetween, and a conductive path alternating between the top metal layer and the bottom metal layer, wherein the conductive path on the top metal layer is remote from the conductive path on the bottom metal layer to reduce magnetic flux interference.
In another embodiment, the invention includes an electronic stripe card having a first conductive path to emit a first magnetic field to mimic a first track in a magnetic card, a second conductive path to emit a second magnetic field to mimic a second track in the magnetic card, a swipe sensor to detect when the electronic stripe card is swiped past a read head, and an interleaved track driver circuit responsive to the swipe sensor, to drive the first and second conductive paths one at a time.
DESCRIPTION OF EMBODIMENTS
In the following detailed description, reference is made to the accompanying drawings that show, by way of illustration, various embodiments of an invention. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention, although different, are not necessarily mutually exclusive. For example, a particular feature, structure, or characteristic described in connection with one embodiment may be implemented within other embodiments without departing from the spirit and scope of the invention. In addition, it is to be understood that the location or arrangement of individual elements within each disclosed embodiment may be modified without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense. In the drawings, like numerals refer to the same or similar functionality throughout the several views.
FIGS. 3 and 4 show diagrams of electronic stripe cards in accordance with various embodiments of the present invention. Electronic stripe card 300 ( FIG. 3 ) includes memory and microcontroller 320 , energy source 310 , track drivers 330 , and electronic stripe tracks 340 . Memory and microcontroller 320 may include application software, account data, and any other software and data. Energy source 310 may be any suitable energy source for providing energy to the remaining devices shown in FIG. 3 . Electronic stripe tracks 340 may be implemented using magnetic field generation circuits described with reference to later figures. Further, electronic stripe tracks 340 may include multiple magnetic field generation circuits to generate magnetic fields corresponding to multiple magnetic card tracks. Track drivers 330 provide driving signals to electronic stripe tracks 340 to effect the generation of magnetic fields.
Electronic stripe card 400 ( FIG. 4 ) includes memory and microcontroller 320 , energy source 310 , and electronic stripe tracks 340 , all of which are described in the previous paragraph. Electronic stripe card 400 also includes track drivers 430 and swipe sensor 410 .
Swipe sensor 410 may sense when the card is swiped past a magnetic card reader head, and track drivers 430 may operate in response thereto. For example, with input from swipe sensor 410 , the microcontroller (uC) can sense when the track driving needs to begin and/or end, making the energy consumption much lower. Swipe sensor 410 may be implemented using optical sensors, mechanical sensors or electrical sensors. Example embodiments of swipe sensors are described further below with reference to later figures. Without a swipe sensor, the track drivers continuously drive the electronic stripes. This will consume energy from the energy source irrespective of if the card is being swiped or not.
FIGS. 5-8 show magnetic field generation in accordance with various embodiments of the present invention. As shown in FIGS. 5 and 6 , flux lines spread out due to absence of magnetic material and therefore are in the opposite direction resulting in canceling of the magnetic fields due to current flow in the top with that of the bottom metal layers.
As shown in FIGS. 7 and 8 , in various embodiments of the present invention, the same bias current is used without magnetic material, while preventing the canceling of field lines by re-routing the bottom metal layer further away along the x-axis. Physical separation of the bottom with the top layers ensures that the flux lines do not cancel each other. The flux lines in the top metal layer might also add-up. Note that the metal width along the x-axis for the top and bottom layers do not have to be the same. This design ensures that the metal conductors in one side of the layout carry current in the same direction. Use of more than two layers of metal can help improve this effect.
Various embodiments of the present invention can be used as the design for electronic stripe tracks 340 ( FIGS. 3 , 4 ) to reuse the same bias current and generate magnetic field(s) that mimic the standard magnetic stripe functionality. This solution does not require magnetic material. Further, this solution does not suffer from flux cancellation.
FIG. 9 shows swipe sensor contacts and a read head in relation to an electronic stripe card. Swipe sensor contacts 920 are shown as two metal islands on electronic stripe card 910 . Read head 930 represents a metal read head in a magnetic card reader such as a point-of-sale (POS) card reader. Since the read head is made out of metal, a swipe sensor that resides on the card with two metal islands spaced closely can be effective. When the read head is in between the two metal islands they will be shorted to each other via the read head. Any other position of the read head will leave these two lines open. By sensing the impedance or by measuring corresponding current/voltage between these two metal islands a swipe sensor such as swipe sensor 410 ( FIG. 4 ) may be implemented. During the swiping action of electronic stripe card 910 through a card reader, the sensor is activated when read head 930 is on top of, and in between, the two metal islands shown at 920 .
FIG. 10 shows a plot of swipe sensor impedance. As shown in FIG. 10 , the impedance between the two islands may drop when the read head shorts the two islands together. The sensor may detect this condition and activate track driving to generate magnetic field(s) to mimic a standard magnetic card.
In some embodiments, multiple swipe sensors exist. For example, one swipe sensor may be on each end of electronic stripe card 910 . In these embodiments, track driving may start when the first sensor is activated, and track driving may stop when the second sensor is activated. Alternatively, the activation of the first sensor may trigger the driving of the stripe and the driving is automatically stopped after sending all the data to the electronic stripe a predetermined number of times. In addition, swipe sensors may be on one or both sides of the electronic stripe card.
FIG. 11 shows a diagram of an electronic stripe card in accordance with various embodiments of the present invention. Electronic stripe card 1100 includes memory and microcontroller 320 , energy source 310 , electronic stripe tracks 340 , and swipe sensors 410 , all of which are described above. Electronic stripe card 1100 also includes interleaved track drivers 1130 .
Most financial cards have two tracks of data. The data stored in these two tracks are read by two independent card reader circuits in the card reader. In a traditional magnetic stripe card since the data for the two tracks are physically recorded on the stripes they are read simultaneously. In various electronic stripe embodiments of the present invention, the data is not stored physically in the stripes, but rather electronically programmed one bit at a time. Since the time slot required for a bit is usually much smaller compared to the time it takes to swipe the entire card, it is possible to drive one track at a time. This is accomplished by first sending the entire data for one of the tracks, followed by the entire track data for the next track. When no data is sent, the track does not consume any current. For a two track system, track interleaving reduces the power consumption by a factor of two and completely eliminates any cross-talk between tracks.
Track interleaving can be done with or without swipe sensors. In some embodiments, there are two swipe sensors for the whole card—one on each end. In these embodiments, activation of one of the swipe sensors may lead to driving of the tracks in an interleaved fashion. The driving can stop after driving the tracks for a predetermined number of times or after the activation of the other swipe sensor. In some embodiments, swipe sensors are dedicate to each track. For example, when one swipe sensor is swiped past a read head, a first track may be driven, and when a second swipe sensor is swiped past the read head, a second track may be driven. Track interleaving for power saving is also valid for designs with more than two tracks.
The various embodiments described herein may be applicable to financial cards, credit/debit cards, and other such cards. Further, the various embodiments may be used in merchant point-of-sale retail locations, automatic teller machine (ATM) locations, or wherever such cards may be read. Still further, the various embodiments may be used for purposes other than financial cards. For example, the various embodiments may be used for access control.
Although the present invention has been described in conjunction with certain embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art readily understand. Such modifications and variations are considered to be within the scope of the invention and the appended claims.
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An electronic stripe card senses when it is being swiped passed a read head, and drives a conductive path to mimic a magnetic card track. Multiple conductive paths may be driven in an interleaved fashion one after another. The card may include multiple swipe sensors to detect when to start and stop driving the conductive paths. The conductive paths may include traces on a top metal layer and bottom metal layer without magnetic material therebetween.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is related to:
(1) U.S. application Ser. No. 565,425 filed contemporaneously herewith entitled "Automatic Target Detection Process" and invented by Thomas L. Corwin, Henry R. Richardson, Michael V. Finn, F. Gregory Close Stanley Kuo, Tom A. Stefanick, R. Norris Keeler, Kent Pflibsen and Lonnie Calmes.
(2) U.S. application Ser. No. 565,480 filed contemporaneously herewith entitled "Physical Model for Automatic Detection Process" and invented by Thomas L. Corwin, Henry R. Richardson, Stanley Kuo, Tom A. Stefanick, Norris Keeler, Kent Pflibsen and Lonnie Calmes.
BACKGROUND OF THE INVENTION
This invention relates generally to a process for detecting and locating a target in a series of two-dimensional images generated by an imaging sensor. More particularly, this invention relates to a novel process for the detection and identification of targets through the use of computer image processing of data collected by an imaging sensor. This invention is particularly useful in the detection of underwater targets from an airborne platform.
Various imaging sensors are used to search areas (or volumes) for particular types of targets which may pose a threat. Examples of such targets include mines and submarines in the ocean, fixed-wing and rotary-wing aircraft, cruise missiles, and rockets in the air, and buried land mines under the soil. Such imaging sensors provide target images in two dimensions. Images in two dimensions can be made either using passive radiation or using active illumination at wavelengths ranging from microwaves, millimeter waves, infrared, and invisible to ultraviolet. These two dimensional images display signal intensity and its variation in two spatial dimensions. Gated cameras used to detect signal returns from pulsed sources (imaging radars or visible lidars) can resolve range from the sensor and therefore can spatially sample a volume in three dimensions. Potential targets within this search volume produce characteristic signatures in the series of images. Examples of imaging sensors exhibiting such target images include, for example, the imaging lidar systems described in U.S. Pat. No. 4,862,257 and U.S. application Ser. No. 420,247 filed Oct. 12, 1989 (now U.S. Pat. No. 4,964,721), both of which are assigned to the assignee hereof and incorporated herein by reference.
Imaging sensors of the general type described hereinabove typically have a display screen for viewing the detected images (e.g., targets). While a human operator viewing a display screen may provide a highly sensitive and reliable means of detecting targets, in some cases computer image processing will be superior. This is because the computer does not suffer from fatigue and inattentiveness as will be the case for human operators, especially in the environment of an aircraft such as a helicopter where noise, heat and vibration can distract from constant surveillance of the sensor display screen. Also, with multiple camera sensors, the visual data rate may be too high for a human to absorb and process effectively. Finally, the inherent complexity of spatial correlations and target signature correlations between images made at different times will require computer processing. Hence, there is a perceived need for computerized data processing techniques which will automatically (i.e., without human operator assistance) detect and locate preselected targets, particularly targets submerged underwater.
SUMMARY OF THE INVENTION
In accordance with the present invention, a novel data processing technique is provided for detecting and locating a target from a plurality of two-dimensional images generated by an imaging sensor such as an imaging lidar system. The present invention processes this series of two dimensional images (made with one or more imaging detectors) in an optimal statistical fashion to reliably detect and locate targets. This invention is a process by which the images are mathematically modified to reduce the deleterious effects of noise and thereby provide the highest possible probability of detection while simultaneously maintaining a very low probability of false alarm. The data processing technique described herein also provides an estimate of the reliability of the detection, the target location and an output image to be displayed for visual confirmation and perhaps classification by the operator. The method of the present invention includes some or all of the following steps: noise reduction, spatial filtering, noise parameter extraction, asymmetric threshold detection, contrast stretching, localization, recognition, range or depth determination and subimage mosaic generation.
The present invention is particularly well suited for processing two dimensional images of underwater targets generated by an imaging sensor located on an airborne platform whereby the underwater target is precisely and accurately detected, located and identified.
The above-discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings, wherein like elements are numbered alike in the several FIGURES:
FIG. 1 is a flow chart depicting the image processing technique of the present invention;
FIG. 2 is a flow chart depicting the asymmetric threshold detection system of the present invention;
FIG. 3 is a flow chart depicting a system for determining target depth; and
FIG. 4 is a flow chart depicting a system for generating mosaic subimages.
DESCRIPTION OF THE PREFERRED EMBODIMENT
While not limited thereto in its utility, the image processing techniques of the present invention are particularly well suited for use in conjunction with a novel imaging lidar system disclosed in U.S. patent application Ser. No. 565,631 filed Aug. 9, 1990 entitled "Imaging Lidar System" and invented by Charles H. Kaman, Bobby L. Ulich, Robert Mayerjak and George Schafer, said application being assigned to the assignee hereof and fully incorporated herein by reference. This imaging lidar system utilizes a pair of pulsed laser transmitters for increased power and six gated camera detectors. The multiple lasers and cameras are optically boresighted to a scanning mirror for increased swath width perpendicular to the heading of the airborne platform.
The imaging processing flow chart in accordance with the present invention is shown in FIG. 1. Reference numeral 1 denotes the start or the initialization of the process. Step 2 is the generation of the images by exposing (e.g., gating) the sensor cameras such as are described in detail in the aforementioned patents and applications. In Step 3, the images are digitized and read into a computer. In Step 4, both the average and the peak intensities are determined for each separate camera image. In Step 5, the gains of the cameras are adjusted so that optimum intrascene dynamic range is achieved in the next exposure under the assumption that the scene brightness is unchanged. This prevents lack of sensitivity (e.g., gain too low) or saturation (e.g., gain too high). In Step 6, all images which are of the same scene are coregistered and averaged in order to reduce the background noise level. These multiple images may be derived from multiple exposures in a time series using one camera from simultaneously obtained images using multiple cameras. In Step 7, bandpass spatial filtering in two dimensions is used to enhance the target signature and to suppress unwanted high spatial frequency features (especially noise) and also low spatial frequencies (background signal). The bandpass spatial filtering can be easily implemented in digital form by replacing bipolar each pixel intensity value with the output of a two dimensional convolution calculation. This two-dimensional convolution is determined using the following equation (as described in Pratt, W. K., Digital Image Processing, John Wilex, New York, 1978, pp. 319-323). ##EQU1## Where:
Q=M×M output (convolved) image matrix
m 1 =row number of Q matrix
m 2 =column number of Q matrix
n 1 =row number of F matrix
n 2 =column number of F matrix
F=N×N input image matrix
H=L×L convolution matrix
The convolution array for a spatial bandpass filter is typically of the form: ##EQU2##
In step 8, the mean and the standard deviation about the mean of the filtered intensities are determined using the following formulas (as described in Frieden, B. R. Probability, Statistical Optics, and Data Testing, Springer-Verlag, New York 1983, pp. 234, 246): ##EQU3## Where
<F>≡mean intensity of image matrix F
σ F ≡standard deviation about the mean of image matrix F
The result is a mean <I> and RMS σ for each image over the X and Y axes.
An important feature of this invention is Step 9 where symmetric or asymmetric threshold detection is performed. This process is shown in detail in FIG. 2 with reference to Steps 20-32. Each pixel intensity I is first scanned in Step 20 to see if it is higher (reflection ) or lower (shadow) than the mean intensity value σ. In general, the background intensity level will not be zero. For the shadow case, if the signal l is more than 5σ below the mean, then the shadow is a probable target (Step 23). If the signal I is more than 3σ below the mean but less than 5σ, then there is a possible shadow target (Step 25). If the signal I is found in Step 24 to be less than 3σ below the mean, then the signal I is judged to be due to noise and no detection is declared in Step 26. For signals brighter than the mean from the test in Step 21, a similar set of threshold comparisons is made. If the signal is more than 5σ higher than the mean in Step 27, a probable reflection detection is declared in Step 28. For signals from 3σ to 5σ higher in Step 29, a possible reflection target is declared in Step 30. Finally, if the signal is less than 3σ high in Step 29, it is declared to be noise (no detection) in Step 31. The output of this routine is then made available to the continuing processing of Step 32.
It will be appreciated that the +/-3σ and +/-5σ threshold values used herein as examples can be made asymmetrical (the plus and minus values would be unequal), and should be selected to produce the desired false alarm rate (especially the smaller threshold value). Reducing the threshold value will increase the false alarm rate, and increasing the threshold value will reduce the false alarm rate. Aysmmetrical threshold can in principle reduce the false alarm for asymmetrical noise sources (such as scintillation or other log normal distributions). The probability of false alarm can be calculated from the threshold value if the probability density function of the noise is known a priori using the following formula: ##EQU4## Where
Z 1 =threshold value; and
P(Z/H o )=probability density of photoelectron counts Z given the hypothesis H o that no target is present is true.
The above formula is described in Van Trees, H. L., Detection Estimation, an Modulation Theory, John Wilex, New York, 1968, pp. 23-31. For a gaussian probability distribution, for example ##EQU5##
Referring again to FIG. 1, the subroutine of FIG. 2 terminates at Step 10 which is the target detection test. If no target was detected by the process of FIG. 2, then the data processing method of this invention continues directly with Steps 16-19 which are self-explanatory "housekeeping" tasks including updating the system parameters and status display (Step 16); updating and scrolling the display image (Step 17); transmitting digital data to a recorder and data link encrypter (Step 18); and waiting for the next camera pulse interrupt signal (Step 19). Thereafter, the entire process is repeated when a new set of images has been obtained.
However, if a target was detected in Step 10, (either a probable or possible shadow or a probable or possible reflection), then Step 22 is performed wherein the part of the whole image near the target (hereinafter referred to as a "subimage") is stretched in contrast to provide the maximum amount of visual information when it is displayed to the operator in Step 17. In Step 12, the X and Y coordinates of the target image are determined using either the peak signal pixel location or an intensity centroid calculation. For peak signal location, the subimage matrix area is searched for the largest intensity value, and the row and column numbers of that pixel are used to estimate the target location. A more accurate target location estimate can be made using the following centroid calculations: ##EQU6##
Where
X≡target centroid location in X coordinate
Y≡target centroid location in Y coordinate
Also, in Step 12, the absolute latitude and longitude of the target are calculated using the sensor platform navigation data (e.g., helicopter or other airborne platform navigational instruments) and a correction for the relative target location with respect to the aircraft by knowledge of the aircraft altitude and compass heading, the target depth, the roll and pitch angles of the sensor line of sight, and the angular offsets of the target image within the sensor field of view, the relative latitude and longitude of the target can be calculated with respect to the aircraft.
The target latitude Φ T and longitude θ T can be found from the following equations: ##EQU7## Where:
P≡Sensor lien of sight pitch angle (+ is forward)
R≡Sensor line of slight roll angle (+ is to left)
n≡Sea water index of refraction (1.34295)
N≡Sensor line of slight nadir angle
r≡Horizontal separation of aircraft and target
A≡Aircraft altitude
C≡Aircraft compass heading (+ is clockwise from North)
θ R ≡Angle of plane containing sensor line of sight and nadir with aircraft heading direction (+ is counterclockwise from heading)
Φ A ≡Aircraft latitude
θ A ≡Aircraft longitude, and
R E ≡Radios of Earth.
In Step 13, previous detection records are checked to see if a prior detection was made at the same location (within the accuracy of the navigation system). If such multiple coincidence detections have occurred, then the estimated probability of detection will be increased. Thus, two estimates of "possible" detections may be upgraded to a "probable" detection.
For imaging lidar sensors such at the Imaging Lidar System of U.S. Pat. No. 4,862,257 or U.S. Ser. No. 565,631, the target range of depth may also be determined in Step 14, which is shown in detail in FIG. 3. Referring now to FIG. 3 and beginning with Step 33, each detection is composed of images made in two range gates, one of which is either just above or just below the range gate in which the target is located. Targets in the range gate will generally be brighter than the background (reflection mode). Targets in front of the range gate will be seen in double shadow/obstruction (shadow mode). Targets behind the range gate will of course not be detected. The truth table in Step 17 compares the target modes in two adjacent range gates for consistency and for determining the actual target range or depth. "Fail" means an untypical, inconsistent result which cannot be a real target signature. The numbers inside the boxes in Step 34 represent the target location. The "2" means within Gate #2 (the lower one), "1", is within Gate #1 (the upper one) and "0" means the target is closer to the imaging sensor than either of the two gates. The boxes in the table in Step 34 also indicate the confidence in the reality of the target detection based on the consistency of the shadow/reflection signature observed.
Referring again to FIG. 1, Step 15 has now been reached where subimages are assembled to form a larger montage or composite image for display and transmittal purposes. FIG. 4 (Steps 36-43) is a detailed flow chart of step 15 in FIG. 1. Upon starting in Step 36 in FIG. 4, objects that pass both the temporal correlation tests (e.g., Was it detected more than once?) and the signature tests (e.g., Is it a spurious background feature?) are processed further. The subimages may be enhanced using known false color techniques (Step 38), annotated to indicate whether the computer has determined a possible or a probable detection (Step 39), shown at their proper depth (or range) either using alphanumerics or by use of a pseudo--3 D display (Step 40) and/or enlarged to show details on small objects (such as mines) even through the sensor display may show a very large field of view (Step 41). For instance, small target images can be enlarged by, for example, a factor of 10. That is, the displayed image is "zoomed in" by a factor of 10. Each target, however, is shown at its correct location on the sensor display so that spatial relationships with other image features are maintained correctly. For large targets or for a series of contiguous small targets, Step 42 displays a larger subimage with no magnification. This would be appropriate for a submarine, for instance. Finally in Step 42, a possible target classification is indicated (for instance, mine or submarine) based upon target size and shape.
Returning again to FIG. 1, after creating the mosaic of subimages in Step 15, the data processing techniques of this invention proceed to update the operator display with sensor health and status data (alphanumerics). In Step 17, the mosaic image is added to the display screen and scrolled appropriately if the sensor platform is moving to match the apparent target velocity. In Step 18, the target data (such as processed subimage, two or three dimensional location and estimated Probability of detection) are recorded and also sent over a data link to a remote location for secondary review and classification.
Finally, in Step 19, the progress goes into a "wait" state until the next images are obtained at which time the data processing technique of FIG. 1 is repeated again to process the new images beginning with Step 1.
The data processing technique described herein is readily understandable by those of ordinary skill in the art and can be easily implemented using existing computer technology. It will provide a reliable and robust target detection, location and classification capability for high data rate imaging sensors such as television cameras, forward looking infrared (FLIR) sensors and imagaing lidars.
Additional image processing may allow amelioration of the degrading effects of particle distribution inhomogeneities and surface wave focussing/defocussing of the laser beam as it is transmitted into the water. For instance, one picture obtained just below the water surface could be saved, scaled, spatially smoothed to compensate for multiple scattering effects and subtracted from all images at greater depths to remove the laser irradiance variations which limit the target detectability.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
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A novel data processing technique is provided for detecting and locating a target from a plurality of two-dimensional images generated by an imaging sensor such as an imaging lidar system. The present invention processes this series of two dimensional images (made with one or more imaging detectors) in an optimal statistical fashion to reliably detect and locate targets. This invention is a process by which the images are mathematically modified to reduce the deleterious effects of noise and thereby provide the highest possible probability of detection while simultaneously maintaining a very low probability of false alarm. The data processing technique described herein also provides an estimate of the reliability of the detection, the target location and an output image to be displayed for visual confirmation and perhaps classification by the operator. The method of the present invention includes some or all of the following steps: noise reduction, spatial filtering, noise parameter extraction, asymmetric threshold detection, contrast stretching, localization, recognition, range or depth determination and subimage mosaic generation. The present invention is particularly well suited for processing two dimensional images of underwater targets generated by an imaging sensor located on an airborne platform whereby the underwater target is precisely and accurately detected, located and identified.
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BACKGROUND OF THE INVENTION
The present invention relates to a heating apparatus for a vehicle that heats circulating fluid in a fluid circuit and uses the heated circulating fluid for heating the passenger compartment. More particularly, the present invention relates to a vehicle heating apparatus having a viscous fluid type heater and a control unit for controlling the heater.
A typical vehicle includes a heater core located in a heating duct. After cooling a liquid-cooled engine, coolant is supplied to the heater core. The heater core uses heat from the coolant to warm air in the duct. The warmed air is then supplied to the passenger compartment.
However, diesel engines and lean burn type engines have a relatively low heating value and thus are not able to heat engine coolant to a sufficient level. It is therefore difficult to maintain the temperature of the coolant in the heater core at a predetermined temperature (for example, 80° C.). This may result in insufficient heating of the passenger compartment.
In order to solve this problem, a viscous fluid type heater for heating engine coolant has been proposed. The viscous fluid heater includes a heating chamber and a water jacket (a heat exchange chamber), which are defined in a housing. The heater also includes a drive shaft and a rotor, which are rotated by the drive force of an engine. The rotor rotates to shear the viscous fluid (for example, silicone oil having a high viscosity) thereby generating heat based on fluid friction. The heater uses the generated heat to heat circulating fluid (engine coolant).
The temperature of the viscous fluid in the heating chamber increases as the speed of the engine increases and is not significantly affected by the temperature of the circulating fluid in the fluid circuit. If a highly viscous silicone oil is used as the viscous fluid in the heating chamber, the oil is likely to deteriorate from the heat and the friction of the rotor when the temperature of the oil exceeds 250° C. The deteriorated oil degrades the efficiency of heat production by shearing. Therefore, the passenger compartment may be inadequately heated.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to provide a vehicle heating apparatus that optimizes the actuation conditions of a viscous fluid type heater for preventing viscous fluid in the heater from deteriorating thereby improving the heat production of the heater.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, an improved heating apparatus for a vehicle, which has a fluid circuit, is provided. The apparatus includes a heating chamber, a heat exchange chamber and a rotor. The heating chamber contains viscous fluid. The heat exchange chamber is located adjacent to the heating chamber and communicates with the fluid circuit. The rotor rotates to shear the viscous fluid to produce heat, which is transferred to the exchange chamber. The rotor also rotates at a variable angular velocity that affects the temperature of the viscous fluid. Circulating fluid flowing in the fluid circuit is heated in the heat exchange chamber. The apparatus further includes a reservoir chamber, a valve device, detecting means and a controller. The reservoir chamber communicates with the heating chamber to store a quantity of the viscous fluid. The valve device regulates a flow of viscous fluid between the reservoir chamber and the heating chamber, and regulates the production of heat in the heating chamber accordingly. The detecting means detects a physical characteristic that is indicative of an overheating condition. The controller controls the valve device to reduce heat production in the heating chamber when the detected characteristic fulfills predetermined conditions.
The present invention may also be embodied in a method of heating a vehicle that has a fluid circuit. The method includes storing a quantity of viscous fluid in a reservoir chamber, supplying a heating chamber with viscous fluid from the reservoir chamber and rotating a rotor to shear the viscous fluid to produce heat. The rotor rotates at a variable angular velocity that affects the temperature of the viscous fluid. The method also includes transferring the produced heat to a heat exchange chamber located adjacent to a heating chamber and regulating a flow of viscous fluid between the reservoir chamber and the heating chamber, which regulates the production of heat in the heating chamber accordingly. The heat exchange chamber communicates with the fluid circuit such that circulating fluid flowing in the fluid circuit is heated in the heat exchange chamber. The method further includes detecting a physical characteristic that is indicative of an overheating condition and controlling the valve device to reduce heat production in the heating chamber when the detected characteristic fulfills predetermined conditions under which the viscous fluid is judged to be excessively heated.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings.
FIG. 1 is a schematic diagram illustrating a vehicle air-conditioning system;
FIG. 2 is a cross-sectional view illustrating a viscous fluid type heater when a communicating passage for connecting a heating chamber with a reservoir chamber is closed;
FIG. 3 is a cross-sectional view illustrating the heater of FIG. 2 when the communicating passage is open;
FIG. 4 is a block diagram illustrating the electric structure of a vehicle air conditioning system;
FIG. 5 is a flowchart showing a routing for determining whether to actuate a heater;
FIG. 6 is a flowchart showing a routine for controlling the heat production of a heater;
FIG. 7(A) is a graph showing the relationship between current fed to an electromagnetic valve in a heater and the speed of an engine;
FIG. 7(B) is a graph showing the relationship between current fed to an electromagnetic valve in a heater and the temperature of engine coolant;
FIG. 7(C) is a graph showing the relationship between current fed to an electromagnetic valve in a heater and the temperature of silicone oil in the heater; and
FIG. 8 is a cross-sectional view illustrating a further embodiment, in which a valve for closing the communicating passage is modified.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A vehicle heating apparatus according to one embodiment of the present invention will now be described with reference to FIGS. 1 to 7.
As shown in FIG. 1, an air conditioning system includes a water-cooled engine E located in the engine compartment of a vehicle, a viscous fluid type heater 10 for heating coolant of the engine E, an air conditioner 40 for adjusting the temperature of a passenger compartment and a fluid circuit W for circulating the coolant through the engine E, the heater 10 and the air conditioner 40. As shown in FIG. 4, the air conditioning system also includes an electronic control unit (ECU) 100 that controls the air conditioner 40 and another ECU 200 that chiefly controls the engine E.
A driving pulley 32 is secured to an end of a crankshaft 31 of the engine E. The engine E further includes a water jacket 33 located about its cylinder block and cylinder head. The water jacket 33 constitutes a part of the fluid circuit W. The circuit W also includes a water pump 34 for circulating coolant in the circuit W, a radiator (not shown) for cooling heated coolant by heat exchange between the atmospheric air and the coolant and a heater core 35 for heating air in the passenger compartment. The water pump 34 is located upstream of the water jacket 33 and is driven by the engine E.
The air conditioner 40 includes a duct 41, a blower 42, a refrigeration circuit and the heater core 35. An outside air inlet 43a and an inside air inlet 43b are connected to the upwind side of the duct 41. The duct 41 further includes a selector 43 that selectively closes and opens one of the inlets 43a and 43b. A defroster nozzle 44a, an upper squirt outlet 44b and a lower squirt outlet 44c are connected to the downwind side of the duct 41. The upper squirt outlet 44b supplies air to the upper portion of the passenger compartment and the lower squirt outlet 44c supplies air to the lower portion of the passenger compartment. The duct 41 includes a pair of selectors 44. One of the selectors 44 selectively opens and closes the nozzle 44a and the upper outlet 44b, whereas the other selector 44 selectively opens and closes the lower outlet 44c. The blower 42 is rotated by a blower motor 45 and generates an air stream to the passenger compartment in the duct 41. The refrigeration circuit includes a pipe, which connects to a compressor (not shown), a condenser (not shown), a gas-liquid separator (not shown), an expansion valve (not shown) and an evaporator 46. The evaporator 46 is located in the duct 41 to cool air in the duct 41.
The heater core 35 functions as a heat exchanger for heating the passenger compartment and is located downwind of the evaporator 46 in the duct 41. Also, the heater core 35 is located downstream of the viscous fluid heater 10 in the fluid water circuit W. The heater core 35 transfers heat from the coolant to air that has passed through the evaporator 46 thereby heating the air. An air mixer 47 is located upwind of the heater core 35 in the duct 41. The mixer 47 is actuated by an actuator (in this embodiment, a servo motor 48) through one or more link plates. The mixer 47 adjusts the amount of air passing through the heater core 35 and the amount of air bypassing the heater core 35, thereby adjusting the temperature of the air flowing into the passenger compartment.
The construction of the viscous fluid type heater 10 will now be described. As shown in FIG. 2, the viscous fluid type heater 10 includes a front housing body 11, a dividing plate 12 and a rear housing body 13, which are secured to each other by a plurality of bolts 15 (only one is shown). A gasket 14 is located between the dividing plate 12 and the rear housing body 13.
A recess formed in the rear face of the front housing body 11 and the front face of the dividing plate 12 define a heating chamber 16 in between. The rear face of the dividing plate 12 and the rear housing body 13 define a water jacket 17. The water jacket 17 is located adjacent to the heating chamber 16 and functions as a heat exchange chamber. An inlet port 18 and an outlet port 19 are provided on the rear outer face of the rear housing body 13. The inlet port 18 introduces circulating coolant from the fluid circuit W into the water jacket 17, and the outlet port 19 drains coolant from the water jacket 18 to the circuit W.
A drive shaft 22 is rotatably supported by a bearing 21 in the front housing body 11. A shaft seal 23, which is, for example, as an oil seal, is located between the drive shaft 22 and the inner wall of the front housing body 11. The shaft seal 23 seals the front side of the heating chamber 16 and prevents viscous fluid from leaking around the drive shaft 22. A disk-shaped rotor 24 is press fitted about the rear end (right end as viewed in the drawing) of the drive shaft 22 and is located in the heating chamber 16.
A reservoir chamber 20 is defined between the rear housing body 13 and the dividing plate 12. A supply lower bore 12a and a recovery upper bore 12b are formed in the dividing plate 12 for communicating the heating chamber 16 with the reservoir chamber 20. The cross-sectional area of the lower bore 12a is larger than that of the upper bore 12b.
The heating chamber 16 and the reservoir chamber 20, which are connected by the bores 12a and 12b, constitute a sealed inner space in the heater housing. The inner space accommodates silicone oil, which is a viscous fluid. The amount of the silicone oil is determined such that the fill factor of the oil is fifty to eighty percent relative to the volume of the inner space at ordinary temperature. Due to the high viscosity of the silicone oil, the silicone oil is drawn from the reservoir chamber 20 via the lower bore 12a and is evenly distributed in the space between the rotor 24 and the inner wall of the heating chamber 16 by rotation of the rotor 24. The level of the silicone oil is lower than the recovery bore 12b and higher than the supply bore 12a when the rotor 24 is not rotating. Therefore, when the rotor 24 is stopped, the silicone oil in the heating chamber 16 is returned to the reservoir chamber 20 through the recovery bore 12b. In this manner, supplying silicone oil from the reservoir chamber 20 to the heating chamber 16 and recovering the silicone oil from the chamber 16 to the chamber 20 circulates the silicone oil between the chambers 16 and 20.
The front housing body 1 has a cylindrical wall 11a, which protrudes forward. A pulley 26 is rotatably supported on the cylindrical wall 11a by an angular bearing 25. The pulley 26 is fixed to the front end (left end as viewed in the drawing) of the drive shaft 22 and is operably coupled to the driving pulley 32 of the engine E, which functions as an external drive source, by a V-belt 36. The pulley 26, the driving pulley 32 and the V-belt 36 constitute a drive train, which directly connects the drive shaft 22 and the rotor 24 with the engine E. The drive shaft 22 and the rotor 24 are therefore integrally rotated by the drive force of the engine E through the pulley 26. Accordingly, the rotor 24 shears the silicone oil in the space between the outer wall of the rotor 24 and the inner wall of the heating chamber 16, which generates heat. Heat generated in the chamber 16 is transmitted to engine coolant in the water jacket 17, which is included in the fluid circuit W.
A vent cylinder 28 is provided in the rear housing body 13. A spool 29 is slidably supported on a part of the cylinder 28 that is located in the reservoir chamber 20. The back-and-forth motion of the spool 29 brings the lower portion of the spool 29 close to and away from the lower bore 12a. A pin 13a secured to the inner wall of the rear housing body 13 prevents the spool 29 from rotating about the vent cylinder 28. The vent cylinder 28 and the spool 29 define a sealed spring chamber 30 in between. The spring chamber 30 accommodates a spring 30a, which urges the spool 29 toward the dividing plate 12. The spring chamber 30 is connected to a vacuum pump 39 via a pressure regulating pipe 38. An electromagnetic valve 37 is located on the pipe 38 for selectively communicating the spring chamber 30 with the atmosphere and with the vacuum pump 39 in accordance with the state of an electromagnetic coil 37a. The vacuum pump 39 is driven by the engine E. The components 28, 29, 30, 30a, 37, 37a, 38 and 39 constitute a valve device that selectively opens and closes the lower bore 12a.
When the air conditioner ECU 100 sends a signal to the electromagnetic valve 37 for de-exciting the coil 37a, the valve 37 is located at the position shown in FIG. 2 thereby communicating the spring chamber 30 with the atmosphere. This equalizes the pressure in the spring chamber 30 with the atmospheric pressure. The combined force of the atmospheric pressure and the spring 30a causes the spool 29 to contact the dividing plate 12. This closes the lower bore 12a thereby stopping flow of viscous fluid from the reservoir chamber 20 to the heating chamber 16. In this state, viscous fluid in the heating chamber 16 is returned to the reservoir chamber 20 through the upper bore 12b, partly because of the Weissenberg effect. Accordingly, the amount of silicone oil in the heating chamber 16 is decreased. In this manner, the heat production (heating value) of the heater 10 is reduced.
When the air conditioner ECU 100 sends a signal to the electromagnetic valve 37 for exciting the coil 37a, the valve 37 is located at the position shown in FIG. 3 thereby communicating the spring chamber 30 with the vacuum pump 39. The pump 39 draws the air in the spring chamber 30 thereby lowering the pressure in the chamber 30 to a pressure that is lower than the atmospheric pressure. The pressure difference between the reservoir chamber 20 and the spring chamber 30 causes the spool 29 to separate from the dividing plate 12 and to open the lower bore 12a. In this state, viscous fluid in the heating chamber 16 returns to the reservoir chamber 20 via the upper bore 12b. However, the amount of returning oil is smaller than the amount of oil that is supplied to the heating chamber 16 from the reservoir chamber 20 through the lower bore 12a. Therefore, the amount of oil in the heating chamber 16 is increased. In this manner, the heat production (heating value) of the heater 10 is increased.
FIG. 4 shows the electrical construction of the air conditioning system of FIG. 1. The air conditioner ECU 100 controls devices such as the viscous fluid type heater 10 and the compressor. The ECU 100 is a micro computer incorporating a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM) and input and output interfaces. The ROM stores various control programs (FIG. 6 shows an example) beforehand.
Connected to the ECU 100 are an ignition switch 50, a heater switch 51, a temperature setter 52, an inside temperature sensor 53, a coolant temperature sensor 54, an oil temperature sensor 55 and the engine ECU 200. The ECU 100 inputs various data and signals from these components. The ECU 100 is also connected to the coil 37a of the electromagnetic valve 37, the blower motor 45, the servo motor 48 and an air conditioner clutch relay 49. The ECU 100 controls these components 37a, 45, 48 and 49 based on the control programs referring to the inputted signals and data.
The ignition switch 50 is a main selector switch of the vehicle and has terminals OFF, ACC, IG and ST. The terminal ST feeds current to a starter motor of the engine E. When selected, the terminal ST sends a signal, which indicates actuation of the starter motor, to the air conditioner ECU 100.
The heater switch 51 is a heating priority switch that is actuated by a passenger when he/she wants the passenger compartment to be heated by the viscous fluid type heater 10. When turned on, the switch 51 sends a heating priority signal to the ECU 100. The switch 51 also functions as a fuel economy priority switch, which gives the highest priority to the fuel economy of the engine E. When turned off, the switch 51 sends a fuel economy priority signal to the ECU 100.
The temperature setter 52 is controlled by a passenger for setting a target temperature of the passenger compartment. The setter 52 sends data of the set temperature to the ECU 100 as analog or digital signals.
The inside temperature sensor 53 includes, for example, a thermistor, and is located in the passenger compartment. The sensor 53 detects the temperature of the passenger compartment (inside temperature) and sends analog data corresponding to the detected temperature to the ECU 100.
The coolant temperature sensor 54 includes, for example, a thermistor and is located at any given point in the coolant water circuit. The sensor 54 detects the temperature of the engine coolant circulating in the fluid circuit W (in this embodiment, the temperature of coolant in the vicinity of the outlet port 19 of the heater 10) and sends analog data corresponding to the detected temperature to the ECU 100.
The oil temperature sensor 55 includes, for example, a thermistor and is located in the heating chamber 16 or in the reservoir chamber 20 of the heater 10. The sensor 55 detects the temperature of silicone oil, or viscous fluid, accommodated in the heating chamber 16 and in the reservoir chamber 20 (in this embodiment, the temperature of oil in the reservoir chamber 20) and sends analog data corresponding to the detected temperature to the ECU 100.
The inside temperature sensor 53 may be replaced with a temperature sensor that detects the temperature of the air outside the passenger compartment (outside temperature). The air conditioner clutch relay 49 includes a relay coil 49a and a relay switch 49b. When the relay coil 49a is excited, the relay switch 49b is closed, which excites the coil in the air conditioner clutch.
The engine ECU 200 is an electronic circuit incorporated in an engine control system that comprehensively controls the engine E. The ECU 200 is a micro computer including a CPU, a ROM, a RAM and input and output interfaces. The ROM stores various predetermined control programs (FIG. 5 shows an example).
The engine ECU 200 is connected to and receives signals and data from an engine speed sensor 56 located in the engine E, a vehicle speed sensor 57, a throttle opening sensor 58 and the air conditioner ECU 100. The ECU 200 refers to the inputted signals and data for controlling the idle speed of the engine E, the amount of fuel injection, the timing of fuel injection, the amount of intake air and the amount of current to a glow plug based on the various control programs. The engine ECU 200 also sends signals (for example, an actuation permission signal Q) to the air conditioner ECU 100.
The engine speed sensor 56 detects the rotational speed of the drive shaft 31 of the engine E, which corresponds to the rotational speed of the rotor 24 in the heater 10. The sensor 56 sends analog or digital data of the detected engine speed to the ECU 200.
The vehicle speed sensor 57 includes, for example, a reed switch type sensor, a photoelectric type vehicle speed sensor or a magnetic reluctance element (MRE) type speed sensor, and is attached to a part of the vehicle. The sensor 57 detects the speed of the vehicle and sends data of the detected vehicle speed to the engine ECU 200.
The throttle opening sensor 58 detects the opening of a throttle valve (not shown) located in the intake pipe of the engine E and sends data of the detected throttle opening to the engine ECU 200.
The engine ECU 200 analyzes the data of the engine speed, the vehicle speed and the throttle opening, which are input from the sensors for computing and judging the acceleration state of the engine E.
FIG. 5 is a flowchart showing a heater actuation determining routine, which is one of the programs executed by the engine ECU 200. The routine is executed at every predetermined crank angle or at interruption requests at every predetermined period of time (for example, 50 millisecond cycle).
When entering this routine, the engine ECU 200 inputs detected data from various sensors at step S11.
The ECU 200 moves to step S12 and judges whether the viscous fluid heater 10 needs to be actuated based on the actual engine speed referring to the graph of FIG. 7(A), which is stored in a memory circuit (for example, the ROM). Specifically, the engine ECU 200 judges whether the engine speed is higher or lower than a predetermined determination engine speed.
In this embodiment, two determination engine speeds D1 and D2 (for example, D1=4000 rpm and D2=2000 rpm) are used in the graph of FIG. 7(A). The speed D1 is greater than the speed D2, and there is a hysteresis curve between the speeds D1 and D2. If current is being supplied to the electromagnetic valve 37, the engine speed is judged to be low as long as the engine speed is lower than the speed D1 and is judged to be high when it exceeds the speed D1. If current is not being supplied to the valve 37, on the other hand, the engine speed is judged to be high as long as it is higher than the speed D2 and is judged to be low when it is lower than the speed D2. When the engine speed is judged to be high, no current is supplied to the valve 37. When the engine speed is judged to be low, current is supplied to the valve 37. In this manner, the actual engine speed is judged to be high or low based on the hysteresis graph of FIG. 7(A). If a single determination speed is used, the current supply to the valve 37 is frequently stopped and started every time the actual engine speed becomes higher or lower than the determination speed. The hysteresis control using the two determination speeds D1 and D2 prevents this frequent switching and thus stabilizes the current supply to the valve 37. However, the valve 37 may be controlled by using a single determination engine speed.
If the actual engine speed is higher than one of the determination speeds (D1 or D2), which is selected based on the graph of FIG. 7(A), the engine ECU 200 moves to step S13. At step S13, the ECU 200 sends an actuation permission signal Q having a non-permitting level (L level) to the air conditioner ECU 100. The signal Q having the non-permitting level causes the air conditioner ECU 100 to lower the heat production of the heater 10.
If the actual engine speed is lower than one of the determination speeds (D1 or D2), which is selected based on the graph of FIG. 7(A), the engine ECU 200 moves to step S14. At step S14, the ECU 200 judges whether the engine speed is accelerating based on throttle opening data input from the throttle opening sensor 58. Specifically, when the throttle opening is greater than a predetermined opening (for example 20%) and the engine speed is increasing, the acceleration state of the engine is judged to be greater to be excessively accelerating.
If than a permitted acceleration and the engine speed is judged
If the engine speed is judged to be accelerating, the engine ECU 200 moves to step S13 for sending an actuation permission signal Q having a non-permitting level (L level) to the air conditioner ECU 100. If the engine speed is not judged to be accelerating, the ECU 200 moves to step S15. At step S15, the ECU 200 sends an actuation permission signal Q having a permitting level (H level) to the ECU 100. The signal Q having the permitting level causes the air conditioner ECU 100 to increase the heat production of the heater 10.
After setting the value of the actuation permission signal Q at step S13 or at step S15, the engine ECU 200 terminates the process of the heater actuation determining routine.
FIG. 6 is a flowchart showing a heat production control routine, which is one of the programs executed by the air conditioner ECU 100. The routine is executed at every predetermined crank angle or at interruption requests at every predetermined period of time (for example, every 50 millisecond).
When the ECU 100 starts this routine, the ECU 100 reads detected data from various sensors at step S21 and moves to step S22. At step S22, the ECU 100 judges whether the heater switch 51 is on, that is, the ECU 100 judges which of a heating priority signal or a fuel economy priority signal is being inputted to the ECU 100.
If the determination of step S22 is negative, that is, if the heater switch 51 is off, the CPU 100 judges that heating of the passenger compartment is not desired and moves to step S23. At step S23, the ECU 100 stops feeding current to the coil 37a of the electromagnetic valve 37 thereby causing the spool 29 to close the lower bore 12a. This stops flow of viscous fluid from the reservoir chamber 20 to the heating chamber 16 and thus lowers the heat production of the heater 10.
If the determination is positive at step S22, that is, if the heater switch 51 is on, the ECU 100 judges that a passenger wishes to warm the passenger compartment and moves to step S24. At step S24, the ECU 100 judges whether the temperature detected by the inside temperature sensor 53 is higher than the temperature set by the temperature setter 52.
If the determination of step S24 is positive, the ECU 100 judges that heating of the passenger compartment is not necessary and moves to step S23. At step S23, the ECU 100 stops feeding current to the coil 37a of the valve 37 thereby lowering the heat production of the heater 10.
If the determination of step S24 is negative, the ECU 100 moves to step S25. At step S25, the ECU 100 judges whether the viscous fluid heater 10 needs to be actuated based on the actual temperature of the engine coolant referring to the graph of FIG. 7(B), which is stored in a memory circuit (for example, the ROM). Specifically, the ECU 100 judges whether the coolant temperature is higher or lower than a predetermined coolant temperature.
In this embodiment, two determination coolant temperatures D3 and D4 (for example, D3=80° C. and D4=70° C.) are used in the graph of FIG. 7(B). The temperature D3 is higher than the temperature D4 and there is a hysteresis curve between the temperatures D3 and D4. If current is being supplied to the electromagnetic valve 37, the coolant temperature is judged to be low as long as the coolant temperature is lower than the temperature D3 and is judged to be high when it exceeds the temperature D3. If current is not being supplied to the valve 37, the coolant temperature is judged to be high as long as it is higher than temperature D4 and is judged to be low when it is lower than the temperature D4. When the coolant temperature is judged to be high, no current is supplied to the valve 37. When the coolant temperature is judged to be low, current is supplied to the valve 37. In this manner, the actual coolant temperature is judged to be high or low based on the hysteresis graph of FIG. 7(B). If a single determination temperature is used, the current supply to the valve 37 is frequently stopped and started every time the actual coolant temperature becomes higher or lower than the determination temperature. The hysteresis control using the two determination temperatures D3 and D4 prevents this frequent switching and thus stabilizes the current supply to the valve 37. However, the valve 37 may be controlled by using a single determination coolant temperature.
If the coolant temperature is judged to be high at step S25, the ECU 100 moves to step S23 and stops feeding current to the coil 37a of the valve 37 thereby lowering the heat production of the heater 10.
If the coolant temperature is judged to be low at step S25, the ECU 100 moves to step S26. At step S26, the ECU 100 judges whether the viscous fluid heater 10 needs to be actuated based on the actual temperature of the silicone oil referring to the graph of FIG. 7(C), which is stored in a memory circuit (for example, the ROM). Specifically, the ECU 100 judges whether the oil temperature is higher or lower than a predetermined oil temperature.
In this embodiment, two determination oil temperatures D5 and D6 (for example, D5=280° C. and D6=270° C.) are used in the graph of FIG. 7(C). The temperature D5 is higher than the temperature D6 and there is a hysteresis curve between the temperatures D5 and D6. If current is being supplied to the electromagnetic valve 37, the oil temperature is judged to be low as long as the oil temperature is lower than the temperature D5 and is judged to be high when it exceeds the temperature D5. If current is not being supplied to the valve 37, the oil temperature is judged to be high as long as it is higher than temperature D6 and is judged to be low when it is lower than the temperature D6. When the oil temperature is judged to be high, no current is supplied to the valve 37. When the oil temperature is judged to be low, current is supplied to the valve 37. In this manner, the actual oil temperature is judged to be high or low based on the hysteresis graph of FIG. 7(C). If a single determination temperature is used, the current supply to the valve 37 is frequently stopped and started every time the actual oil temperature becomes higher or lower than the determination temperature. The hysteresis control using the two determination temperatures D5 and D6 prevents this frequent switching and thus stabilizes the current supply to the valve 37. However, the valve 37 may be controlled by using a single determination oil temperature.
If the oil temperature is judged to be high at step S26, the ECU 100 moves to step S23 and stops feeding current to the coil 37a of the valve 37 thereby lowering the heat production of the heater 10.
If the oil temperature is judged to be low at step S26, the ECU 100 moves to step S27. At step S27, the air conditioner ECU 100 performs sampling of an actuation permission signal Q sent from the engine ECU 200 and moves to step S28. At step S28, the ECU 100 judges whether the signal Q has a permitting level (H level).
If the determination of step S28 is negative, the ECU 100 moves to step S23 and stops feeding current to the coil 37a of the valve 37 thereby lowering the heat production of the heater 10. If the determination of step S28 is positive, the ECU 100 moves to step S29. At step S29, the ECU 100 feeds current to the coil 37a of the valve 37 thereby moving the spool 29 backward. This opens the lower bore 12a and causes viscous fluid in the reservoir chamber 20 to flow into the heating chamber 16. As result, the heat production of the heater 10 is increased.
The above embodiment has the following advantages.
(A) When the heater 10 satisfies all the conditions (S22, S24, S25, S26 and S28) for increasing its heat production, the electromagnetic valve 37 is controlled such that the lower bore 12a is opened. This allows viscous fluid in the reservoir chamber 20 to flow into the heating chamber 16. In this manner, the heat production of the heater 10 is increased when it is appropriate. Accordingly, the circulating fluid (the engine coolant) is heated and the temperature of the coolant is maintained at a predetermined temperature (for example, 80° C.).
(B) When any one of the conditions for enhancing the heat production of the heater 10 is not satisfied, the electromagnetic valve 37 is controlled such that the spool 29 closes the lower bore 12a. This prohibits the viscous fluid in the reservoir chamber 20 to flow into the heating chamber 16. At this time, the upper bore 12b is open and viscous fluid in the heating chamber 16 is returned to the reservoir chamber 20 through the bore 12b. As long as the lower bore 12a is closed, the amount of the viscous fluid in the heating chamber 16 is gradually decreased. Accordingly, the heat production of the heater 10 is reduced. This prevents the viscous fluid from retaining heat. The temperature of the viscous fluid is thus not excessively increased. Accordingly, the heater 10 resists deterioration of the viscous fluid by heat. The low amount of viscous fluid in the heating chamber 16 also prevents the viscous fluid from being deteriorated by friction between the rotor 24 and the fluid.
(C) When the amount of viscous fluid in the heating chamber 16 is decreased for reducing the heat production of the heater 10, shearing resistance of the viscous fluid, which acts on the rotor 24, is lowered. This reduces the load on the engine E for rotating the drive shaft 22 and the rotor 24. This improves the fuel economy of the engine E.
(D) As shown in FIGS. 7(A), 7(B) and 7(C), three pairs of different determination values are used. This prevents the heater 10 from being frequently turned on and off thereby reducing the number of abrupt changes in the torque acting on the engine E.
It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the invention may be embodied in the following forms.
(1) Instead of the spool 29 and the electromagnetic valve 37 shown in FIGS. 2 and 3, an electromagnetic solenoid 61 as illustrated in FIG. 8 may be used as a valve device for closing the lower bore 12a. As shown in FIG. 8, a solenoid coil 62 is provided on the back face of the rear housing body 13 and is supported by a plate 63. A rod 64 is located in the central portion of the coil 62. The rod 64 slides with respect to the rear housing body 13. In this case, the distal end of the rod 64 is located in the reservoir chamber 20 and faces the lower bore 12a. Further, the area of the distal end face of the rod 64 is greater than the area of the lower bore 12a so that the rod 64 closes the bore 12a when contacting the dividing plate 12. A coil spring 65 is located between the distal end of the rod 64 and the inner wall of the reservoir chamber 20 for urging the rod 64 toward the plate 12.
When the air conditioner ECU 100 starts feeding current to the solenoid coil 62, electromagnetic force produced in the solenoid coil 62 moves the rod 64 backward thereby opening the lower bore 12a. On the other hand, when the ECU 100 stops feeding current to the solenoid 62, the urging force of the spring 65 causes the distal end face of the rod 64 to contact the plate 12 thereby closing the bore 12a. This construction of the solenoid 61 and the spring 65 simplifies the valve device for closing the lower bore 12a.
(2) The viscous fluid type heaters illustrated in FIGS. 2 and 8 only have the valve device for closing the lower bore 12a. However, a similar device may be provided for closing the upper bore 12b. This construction allows the circulation of the viscous fluid to be more subtly controlled.
(3) Instead of the engine speed sensor 65, which detects the rotational speed of the drive shaft 31 of the engine E, a sensor that detects the rotational speed of the drive shaft 22 or the rotor 24 of the heater 10 may be used.
(4) In the electric construction shown in FIG. 4, the air conditioner ECU 100 is constructed independently from the engine ECU 200. The engine ECU 200 judges the engine speed and the acceleration state of the engine E and sends the resultant data to the ECU 100 as an actuation permission signal Q. However, the ECUs 100 and 200 may be integrated. In this case, the integrated unit controls the heat production of the heater 10. Although an increased number of ports of input and output interfaces and prolonged time period between each interruption process are required, the construction of the integrated control unit reduces its manufacturing cost.
The term "viscous fluid" in this specification refers to any type of medium that generates heat based on fluid friction when sheared by a rotor. The term is therefore not limited to highly viscous fluid or semi-fluid material, much less to silicone oil.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.
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A heating method and apparatus for vehicles. A viscous fluid type heater is located in a vehicle fluid circuit. The heater has a heating chamber that holds viscous fluid and a rotor. The rotor rotates to shear the viscous fluid and produce heat. The heat is transmitted to a heat exchange chamber located adjacent to the heating chamber. The rotor rotates at variable rotation velocity, which affects the temperature of the viscous fluid. Circulating fluid in the fluid circuit and is heated in the heat exchange chamber. The heater includes a reservoir chamber communicating with the heating chamber to store viscous fluid. The heater has a valve that selectively connects and disconnects the reservoir chamber with the heating chamber to regulate heat production. The apparatus has a detecting device for detecting a temperature or a speed that is indicative of the temperature of the viscous fluid. The apparatus also has a controller for controlling the valve to reduce heat production when the temperature of the viscous fluid is deemed to be high.
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[0001] This present utility model patent application addresses a constructive improvement to an anti-theft lock device applied to automobile trunks providing pioneering advantages in relation to the assembly system and lock protection applied to automobile trunks, including locks with coupled electrical devices, resulting in significant productivity gain during assembly of the parts with the trunk hood, when analyzing advantages from the industrialization viewpoint. It also provides significant gains in terms of safety against vandalism and or theft of the vehicle.
[0002] The significant gain in productivity enable automobile sector companies, particularly assembly plants, to obtain reduced fixed assembly costs for the trunk hood lock.
[0003] Further, with the system of assembling the now improved lock, assembly quality is guaranteed, minimizing out-of-spec problems, both in assembly and in the working of said lock during its useful life, having reduced corrective maintenance for this vehicle item.
[0004] From the point of view of safety against theft, the solution now claimed adds value directly to the automotive vehicle by increasing difficulty in accessing the trunk of the vehicle, thus providing greater reliability against theft and untoward action.
[0005] Bearing in mind the increasing demand for vehicles that offer maximized security to the end consumer, the improvement now claimed fulfills this need, thanks to the optimization of the product now claimed.
BACKGROUND ART
[0006] From this angle, comparing the improved solution with simple trunk-lock type models that are already known to the state of the art, it is clear that the latter are deficient in their constructive and functional concept. Assembly of such trunk locks is lacking in productivity, since the assembler has no physical or visual access which is required for adequate assembly procedure of trunk locks.
[0007] This inferior work condition generates a loss in productivity, which comprises ambitious production targets.
[0008] Moreover, in view of the limited number of potential assemblies of the lock-type items, such items have out-of-spec rates higher than the ranges defined by the industry's quality control sectors.
[0009] Another well-known fact is that an analysis of the value of the trunk lock item, from the point of view of safety against theft, reveals their vulnerability against the action of offenders. This is aggravated by the fact that it is easy to break the lock by releasing it from its latch on the metallic structure of the trunk.
[0010] Still within the scope of perceived safety, the solutions known to the state of the art can be violated, by totally withdrawing the body from the trunk door, or by the offender creating an opening in the trunk metalwork, precisely in the latch area of the lock-type item. A screwdriver type tool, for example, can easily be forced into such opening, breaking open the bracing item, the function of which is to provide the locking or release of the trunk hood.
[0011] Having stated this, a more in-depth analysis of the assembly and operation conditions of trunk lock-type items leads one to the conclusion that the design is lacking in terms of reliability. However, the new equipment mentioned herein achieves the functional design targets. Having analyzed the negative aspects mentioned herein, understandably there is room for development of products of the same nature, but with greater versatility in the assembly process, resulting in improved productivity, with quality and reliability, from the point of view of effectiveness with regards preventing theft offenders.
SUMMARY OF THE INVENTION
[0012] In view of such a challenge, the applicant developed innovative solutions in trunk locks, more specifically applied in common trunk locks or trunks locks with electric components, the constructive concept of which provides advantages mentioned herein in relation to the state of the art. The assembly system of said improved item discards the lock pin, facilitating its assembly on the trunk hood, minimizing the assembler's physical and visual action, thus guaranteeing assembly integrity and avoiding out-of-spec assembly problems of said item.
[0013] Moreover, the constructive concept applied to the now improved trunk lock provides for the locking of the fastening clinch element, in conjunction with a clench ring element, designed to receive a perfect-fitting latch from the fastening clinch element. It also contributes value by adding a function which resides in providing protection for the bracing element, since it avoids access to this element by any kind of tool used in violations against the trunk.
[0014] Within this same constructive concept now claimed, the applicant also presents a constructive variation applicable both to common trunk locks and to trunk locks with electric components, conferring the new product greater flexibility in the assembly of different assembly specifications.
[0015] In short, for current levels of competitiveness in the automobile industry, it is essential to strive for improvements in productivity with quality, reduce operating costs of assembly of trunk lock-type items, and also add unique reliability in the safety aspect against acts of violation. The solution now claimed meets the technical and commercial requirements previously set forth in this document, and also fully complies with the patentability requirements prescribed in the Industrial Property Law.
DESCRIPTION OF THE FIGURES
[0016] In complement to this present description, in order to obtain a better understanding of the features of the present utility model application, a set of drawings is attached to this description, exemplified by, but not limited to, the following:
[0017] FIG. 1 depicts the area of application of the anti-theft trunk lock item now claimed on an automotive vehicle;
[0018] FIG. 2 depicts a perspective view of the outer section of the anti-theft trunk lock item now claimed, assembled on the automotive vehicle trunk hood;
[0019] FIG. 3 depicts a perspective representation of the preferred embodiment for the anti-theft trunk lock item now claimed, more specifically of its inner section and assembled on the automotive vehicle trunk hood;
[0020] FIG. 4 depicts an exploded view of the preferred embodiment for the anti-theft trunk lock item now claimed;
[0021] FIG. 5 depicts a side view of the preferred embodiment for the anti-theft trunk lock item now claimed, assembled on the automotive vehicle trunk hood;
[0022] FIG. 6 depicts an “LL” cut view of the preferred embodiment for the anti-theft trunk lock item now claimed, assembled on the anti-theft trunk hood now claimed, assembled on the automotive vehicle trunk hood;
[0023] FIG. 7 depicts a representation of the front view of the inner section of the preferred embodiment for the anti-theft trunk lock item now claimed, assembled on the automotive vehicle trunk hood;
[0024] FIG. 8 depicts an “MM” cut view of the preferred embodiment for the anti-theft trunk lock item now claimed, assembled on the automotive vehicle trunk hood;
[0025] FIG. 9 depicts the first stage of assembly of the preferred embodiment for the anti-theft trunk lock item now claimed, on the automotive vehicle trunk hood;
[0026] FIG. 10 depicts a representation of the second stage of assembly of the preferred embodiment for the anti-theft trunk lock item now claimed, on the automotive vehicle trunk hood;
[0027] FIG. 11 depicts the third stage of assembly of the preferred embodiment for the anti-theft trunk lock item now claimed, on the automotive vehicle trunk hood;
[0028] FIG. 12 depicts a representation of the fourth stage of assembly of the preferred embodiment for the anti-theft trunk lock item now claimed, on the automotive vehicle trunk hood;
[0029] FIG. 13 depicts a perspective of the first variation to the preferred embodiment for the anti-theft trunk lock item now claimed, more specifically of its internal section and assembled on the automotive vehicle trunk hood;
[0030] FIG. 14 depicts an exploded perspective of a first variation to the preferred embodiment for the anti-theft trunk lock item now claimed;
[0031] FIG. 15 depicts a side view of a first variation to the preferred embodiment for the anti-theft trunk lock item now claimed, assembled on the automotive vehicle trunk hood;
[0032] FIG. 16 depicts an “NN” cut view of a first variation to the preferred embodiment for the anti-theft trunk lock item now claimed, assembled on the automotive vehicle trunk hood;
[0033] FIG. 17 depicts a front view of the internal section of a first variation to the preferred embodiment for the anti-theft trunk lock item now claimed, assembled on the automotive vehicle trunk hood;
[0034] FIG. 18 depicts an “OO” cut view of a first variation to the preferred embodiment for the anti-theft trunk lock item now claimed, assembled on the automotive vehicle trunk hood;
[0035] FIG. 19 depicts a side view of the first stage of assembly of a first variation to the preferred embodiment for the anti-theft trunk lock item now claimed;
[0036] FIG. 20 depicts the second stage of assembly of a first variation to the preferred embodiment for the anti-theft trunk lock item now claimed, on the automotive vehicle trunk hood;
[0037] FIG. 21 depicts the third and final stage of assembly of a first variation to the preferred embodiment for the anti-theft trunk lock item now claimed, on the automotive vehicle trunk hood;
[0038] FIG. 22 is a representation of the protection obtained by the bracing element applicable to the anti-theft trunk lock item now claimed;
[0039] FIG. 23 depicts how to eliminate possible gaps between the anti-theft trunk lock component now claimed and the latch area of the trunk hood.
DETAILED DESCRIPTION OF THE INVENTION
[0040] The following detailed description should be read and interpreted with reference to the drawings, where identical elements in different drawings are numbered equally, that is to say the same number is kept for an element used in two embodiments of the improvement. The drawings are highly diagrammatical, representing selected embodiments, but are not intended to limit the scope of the utility model, which is merely limited to that set forth in the set of claims.
[0041] With regards the illustrated drawings, in FIG. 1 the applicant understands that it is appropriate to present a representation of the anti-theft lock system ( 1 ), duly assembled on the automotive vehicle ( 2 ), and FIG. 2 is a graphical representation of the outer part (E) of the anti-theft lock-type product ( 1 ) on the trunk hood ( 3 ).
[0042] However, FIG. 3 effectively demonstrates the improvement in the anti-theft lock ( 1 ) now applied for, in a preferred embodiment, based on which improvements can be obtained in terms of assembly and reliability of the product that is the subject matter of the patent application.
[0043] FIG. 4 is an exploded representation of the elements which form the trunk lock anti-theft product ( 1 ), and these are defined as clench ring element (A), sealing joint (B), lock cylinder element (C) and fastening clinch element (D).
[0044] There is also a so-called bracing element (F), which is directly benefited by the implementation of the improvement in the subject matter of the patent application. Said bracing element, however, has not undergone any form of modification and therefore will not be the subject matter of any claim in this application.
[0045] The constructive concept of the clench ring element (A) is based on a main body, in circumference form, which has a hollowed latch area (AI) in the middle section, the function of which is to provide for the latch at the front section of the lock cylinder element (C).
[0046] Furthermore, an upper (A 2 ) and lower latch element (A 3 ) is provided, the function of which is to provide for fastening of the upper (D 1 ) and lower (D 2 ) ends of the fastening clinch element (D).
[0047] Further in relation to the constructive concept of the clench ring element (A), a relief lock (A 4 ) is provided, the function of which is to provide for locking of the fastening clinch element (D), when executing the final stage of assembly of the anti-theft lock ( 1 ).
[0048] For improved structure of the clench ring element body (A), it has structural grooves (A 5 ) in one of its phases.
[0049] In turn, the outer profile of the sealing joint element ( 2 ) has a circumference form, the outer diameter of which is similar to the outer diameter of the clench ring element (A), also having a hallowed latch area (B 1 ) in its middle section, the latter having a profile similar to that in the hollowed latch area (A 1 ).
[0050] In turn, the lock cylinder element (C) is changed from the original project, introducing upper (C 1 ) and lower attachment areas (C 2 ), the function of which is to provide the latch of the upper (D 1 ) and lower (D 2 ) ends of the fastening clinch element (D), during the first stage of assembly of the anti-theft lock ( 1 ).
[0051] The fastening clinch element (D) is characterized by having upper (D 1 ) and lower (D 2 ) latch ends, having an inflexion segment (D 3 ) in its middle section, the function of which is to provide locking for the fastening clinch (D), together with the relief lock (A 4 ) of the clench ring element (A).
[0052] The interaction between the elements which make up the anti-theft lock product ( 1 ) may be fully understood in FIGS. 5 , 6 , 7 and 8 respectively.
[0053] The functional assembly concept of the anti-theft lock product ( 1 ) is defined by a first stage, represented in FIG. 9 , where the clench ring (A) and sealing joint (B) elements, are previously assembled on the body of the lock cylinder element (C).
[0054] Assembly of the fastening clinch element (D) is also carried out in this first stage, where the upper (D 1 ) and lower (D 2 ) ends are fitted on the upper (C 1 ) and lower (C 2 ) attachment areas. The result of this action can be seen in FIG. 10 .
[0055] Having completed the first stage, the operator then starts the locking itself of the anti-theft lock product ( 1 ), by applying a radial dislocation force (fa), directly in the middle section, namely, the inflexion segment (D 3 ) of the fastening clinch element (D), forcing the upper (D 1 ) and lower (D 2 ) ends to move (Fb) from the houses represented by the upper attachment areas (C 1 ) and lower attachment area (C 2 ) of the lock cylinder element (C).
[0056] The radial dislocation of the fastening clinch element (D) displaces until the upper (D 1 ) and lower (D 2 ) form an angle of 90 degrees in relation to the clench ring element (A), and the effective result of this action is represented in FIG. 11 .
[0057] In the third stage of assembly, the operator applies a linear dislocation force (Fc), also directly on the middle section, namely the inflexion segment (D 3 ) of the fastening clinch element (D), forcing the upper (D 1 ) and lower (D 2 ) ends to move over the upper latch element (A 2 ) and lower latch element (A 3 ) respectively. Dislocation comes to an end when there is interference of the inflexion segment (D 3 ) on the relief lock (A 4 ), provided for in the clench ring element (A), causing effective locking of the anti-theft lock product ( 1 ). This is clearly seen in FIG. 12 .
[0058] In complement to the preferred embodiment widely described in this document, the applicant presents a first variation thereto in terms of constructive and functional concepts, characterized mainly by the fact that the assembly can be applied to any kind of trunk lock, such as trunk locks with electric components assembled in the body of the lock cylinder element (C). This can be seen in FIGS. 13 , 15 and 17 .
[0059] In this context, FIG. 14 is a representation in exploded view of the elements which make up the anti-theft lock product ( 1 ′), said elements being defined as follows: universal clench ring element (X), sealing joint (B), lock cylinder element (C) and fastening clinch element (Y).
[0060] The constructive concept of the universal clench ring element (X) is based on a main body, in circumference form, which has a hollowed latch area (X 1 ) in the middle section, the function of which is to provide latch on the front section of the lock cylinder element (C).
[0061] The left-hand adjoining section of the universal clench ring element (X) has a support area (X 2 ) which can be defined as a side extension of the body of the universal clench ring element (X), the main function of which is to support the assembly elements and to limit the fastening clinch element (Y).
[0062] With regards assembly of the elements, a pair of latch structures is defined, having alpha-numeric references (X 3 ) and X 4 ) respectively, and placed parallel, these having the first function of providing a latch by pressure of rods (Y 1 ) and (Y 2 ) of the fastening clinch element (Y), and a second function resides in providing a lock movement guide of this same fastening clinch element (Y). It is important to highlight that the rods (Y 1 ) and (Y 2 ), are linear, having rounded ends to allow their free movement through the guides formed by two pairs of latch structures (X 3 ), (X 4 ), (X 5 ) and (X 6 ) respectively.
[0063] In complement to said movement guide function, there is a second pair of latch structures, having alpha-numerical references (X 5 ) and (X 6 ), respectively, being positioned parallel, but enveloping the core of the universal clench ring element (X), thus guaranteeing improved stability in locking movement.
[0064] The constructive concept of the universal clench ring element (X) also provides a wall (X 7 ), the function of which is to provide limit of movement of the fastening clinch element (Y), the latter associated to the high relief area (X 8 ) creating a latch for the inflexion segment (Y 3 ) having the function of preventing the free movement of the fastening clinch element (Y) itself until the assembly procedure of the lock itself is carried out.
[0065] Finally, the universal clench ring element (X) also has a lowered lock (X 9 ) in the high relief area (X 8 ), the latter having the function of providing the locking of the fastening clinch element (Y), more specifically to provide locking by the inflexion segment latch (Y 3 ) of this element, guaranteeing efficient assembly of the anti-theft lock product ( 1 ′).
[0066] In turn, the sealing joint (B) is precisely the same element applied in the assembly of the preferred embodiment of the trunk lock, and the same occurs with the lock cylinder element (C).
[0067] The fastening clinch element is altered in relation to the fastening clinch element (D) defined in the preferred embodiment, giving origin to a second version called fastening clinch element (Y), characterized by having rods (Y 1 ) and (Y 2 ), the function of which is to provide guidance and movement for the lock of the anti-theft lock product ( 1 ′).
[0068] The interaction of the component elements of the anti-theft lock product ( 1 ′), may be fully understood in FIGS. 15 , 16 , 17 and 18 respectively.
[0069] The functional concept of assembly of the anti-theft lock product ( 1 ′) is defined by a first stage, represented in FIG. 19 , where the fastening clinch element (Y) is assembled on the body of the universal clench ring element (X), and this assembly occurs by the latch of the rods (Y 1 ) and (Y 2 ) of the fastening clinch element (Y) on the latch structures (X 3 ) and (X 4 ) respectively, by light pressure of the rods on the superficial fissure of said structures, resulting in a click-type latch. The result of this action can be seen in FIG. 20 , which indicates the position of the fastening clinch element (Y) immediately prior to activation.
[0070] With the execution of said latch of the fastening clinch element (Y) and its correct positioning prior to effective locking of the device, the operator may proceed with the assembly between the universal clench ring (X) and sealing joint (B) elements, on the body of the lock cylinder element (C).
[0071] Having completed the first stage, the operator starts the locking per se of the anti-theft lock product ( 1 ′), applying a linear dislocation force (Fc), directly on the fastening clinch element (Y), releasing the inflexion area (Y 3 ) of the fastening clinch element (Y) of the latch formed by the wall structures (X 7 ) and high relief area (X 8 ), making the rods (Y 1 ) and (Y 2 ) move in the guides formed in the inner section of the latch structures (X 3 ) (X 5 ) and (X 4 ); (X 6 ) respectively.
[0072] Dislocation (Fc) of the fastening clinch element (Y) is up to the limit in which the inflexion segment (Y 3 ) reaches the lowered lock (X 9 ) in the high relief area (X 8 ) so that the device formed by the anti-theft lock ( 1 ′) is effectively locked to the trunk hood ( 3 ), and this condition is verified.
[0073] Concerning the final status, FIG. 22 is a representation of an attempted breakage of the anti-theft lock ( 1 ), where the greater outer diameter of the clench ring (A), generates a height barrier (H 1 ), preventing tool access ( 4 ) to the bracing element (F), and thus it cannot be undone.
[0074] The height (H 1 ) also hinders the total detachment of the anti-theft lock ( 1 ), from the latch area provided on the trunk hood ( 3 ).
[0075] Finally, FIG. 23 depicts the disposition between the clench ring element (A) and trunk hood ( 3 ), generating a width (H 2 ) which eliminates excessive gaps in assembly, thus preventing the anti-theft lock ( 1 ) from being moved.
[0076] Therefore the locking system is not compromised.
[0077] Therefore, it can be seen from all that described and illustrated that this constructive improvement to an anti-theft lock device applied to automobile trunks, as it fills an important gap in the automotive sector, particularly because it offers a technical and operational alternative for the trunk lock product, both for a simple setup and for a setup including electric elements in the body of the lock cylinder element (C), and thus is worthy of the respective privilege.
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A constructive improvement to an anti-theft lock device applied to automobile trunks, whose innovative solution implies a new anti-theft lock ( 1 ), applicable both to common trunk locks and to trunk locks having electric assembly elements, wherein said improvement provides greater productivity during the assembly of said item, in addition to providing greater reliability to the anti-theft safety system, and this is achieved thanks to a constructive concept wherein the anti-theft lock item ( 1 ) comprises a clench ring element (A), sealing joint (B), lock cylinder element (C) and fastening clinch element (D). The clench ring element (A) comprises a hollowed latch area (A 1 ), an upper latch element (A 2 ) and a lower latch element (A 3 ), also having a relief lock (A 4 ), in addition to structural grooves (A 5 ). In turn, the fastening clinch element (D) has upper (D 1 ) and lower (D 2 ) latch ends, having an inflexion segment (D 3 ) in its middle section, and both these elements are fitted into the lock cylinder element (C). Once assembled, the anti-theft lock item ( 1 ) prevents the access of tools ( 4 ) to the bracing element (F), thanks to the formation of a height barrier (H 1 ), also generating a width (H 2 ) which eliminates assembly gaps.
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TECHNICAL FIELD
This relates to integrated circuits useful in data processing and more particularly in microprocessor apparatus.
BACKGROUND OF THE INVENTION
In data processing apparatus such as microprocessors, it is usual to include one or more databuses which serve for the transmission of data streams between the various parts of the apparatus.
As such apparatus becomes more complex and more and more circuits are loaded on a particular databus, the loading of the databus increases and the demand on the components driving the databus increases. At the same time such components are decreasing in size and less able to handle demanding loads with the high speeds that are important for state of the art data processing apparatus.
SUMMARY OF THE INVENTION
To solve this problem it is proposed to operate a databus in a precharged mode to improve the speed with which a signal pulse can be impressed on the databus without increasing the drive needed by the driver to impress such pulse. Precharging of output nodes in logic networks and in sense amplifiers of memory bit lines has become standard practice in high speed data processing apparatus but has been little used in microprocessors because of the complexity it could be expected to introduce in the system timing. In those instances where a precharging has been employed, the circuit becomes noisesensitive, and it has tended to be unreliable. Instead the data stream has been introduced into the databus in the typical microprocessor by way of a simple tristable buffer.
In accordance with my invention, a novel dynamic coupling circuit is provided at each node where coupling data into the databus is to occur and these circuits cooperate with a common dynamic precharging transistor. In a preferred embodiment, the coupling network includes a complementary pair of clocked tristate drivers cooperating with a single clocked precharge transistor to provide a high-speed pull-down driver cooperating with a pull-up precharging transistor.
BRIEF DESCRIPTION OF THE DRAWING
Each of FIGS. 1 and 2 of the drawing shows an illustrative embodiment of the invention useful in coupling a data stream developed by a logic network to a databus; and
FIG. 3 shows a plurality of logic networks coupled to a common databus in accordance with the invention.
DETAILED DESCRIPTION
With reference now to the drawing, in FIG. 1 a databus 11 is included in a microprocessor typically as a conductive layer extending on the surface of a silicon chip within which are housed the various transistors which form the circuits which make up the microprocessor.
A precharge p-type transistor 12 is used to charge the databus periodically to the high voltage associated with the higher output state of the two binary signal states which the databus can assume, which in a CMOS device typically are the voltage on the two opposite sides of the power supply. It will be assumed that all the transistors described are of the enhancement mode type. Transistor 12 has its source connected to the power bus 13 which is at the high potential V DD of the power supply associated with the microprocessor. The drain of transistor 12 is connected to the databus and its gate electrode to a line 14 to which are applied the clock pulses used to control the databus transaction. The application of a low clock pulse to the gate electrode permits the databus to be charged essentially to V DD . The transistor 12 is designed to have a relatively large beta, the ratio of channel width to channel length, so that it can pull the databus up to V DD quickly.
At each of the nodes where data are to be introduced to the databus, there is provided a dynamic coupling network comprising p-type transistors 16 and 17 and n-type transistors 18 and 19, all connected to have their main conductive channels serially connected between the high and low power buses 13,20 of the power supply of the microprocessor. P-type transistor 17 has its gate supplied by a line 21 which supplies the complement of the clock pulses on line 14. N-type transistor 18 has its gate connected to line 14 which provides true clock pulses to it. The gates of p-type transistor 16 and n-type transistor 19 are each supplied with the output of the AND gate 22, one of whose inputs is the data stream which is provided by the logic network 23 and which is to be transferred to the databus 11. The other input to the AND gate 22 is an enabling pulse from a control circuit (not shown) which controls when the data stream from logic network 23 is to be applied to the databus. The node 24 between transistors 17 and 18 forms the coupling node to the databus 11.
In operation, when the clock line is low, p-type transistor 12 will be conducting, but p-type transistor 17 and n-type transistor 18 will be nonconducting so that the databus will approach the voltage of V DD , essentially independent of the input to transistors 16 and 19. When the clock goes high, p-type transistor 12 will be nonconducting, p-type transistor 17 and n-type transistor 18 will be conducting, and whether the databus remains at V DD or will be pulled down close to the potential of the low potential bus 20 of the power supply, typically ground, will depend on the value of the input to the transistors 16 and 19. When this input is high, which requires both an enabling pulse and a "one" at the output of the logic network, n-type transistor 19 will conduct but p-type transistor 16 will not conduct, permitting node 24 and the databus to approach the ground potential of the low potential bus 20 of the power supply. However, when this input is low, n-type transistor 19 will not conduct but p-type transistor 16 will conduct, thereby maintaining node 24 and the databus essentially at the potential V DD of the high potential bus 13 of the power supply.
For this arrangement to be competitive with alternative arrangements, it is important that the coupling arrangement permit speedy transfer of data to the databus and, accordingly, it is advantageous that the capacitance added to the databus by the precharge and coupling circuits be small. This is achieved by appropriately choosing the betas of the various transistors used. In particular, since only one precharge transistor 12 is needed for each databus, it is tolerable to utilize a transistor of relatively large beta for this role. However, there will be at each coupling node a coupling arrangement of the kind described so that the ability to use transistors of smaller betas is important here. In particular, since the speed and current handling capacities of p-type transistors 16,17 are relatively unimportant, each is designed to have a small beta, typically about one sixth that of transistor 12. However, p-type transistors 16 and 17 are important to keep the databus connected to the positive bus 13 of the power supply by way of a finite impedance to reduce noise induction from the power bus, and to prevent accidental discharge of the bus. If the noise induction is small, the betas of transistors 16 and 17 can be small. On the other hand, the speed of the pair of n-type transistors 18 and 19 should preferably be comparable to those of transistor 12 and, accordingly, preferably each is designed to have a beta typically about that of transistor 12.
In FIG. 2, there is shown an alternative arrangement for coupling to a databus 101 in accordance with the invention. There is included a p-type precharging transistor 102 whose source is connected to the positive bus 103 of the power supply (not shown) and whose drain is connected to the databus. The gate is connected to a line 104 to which are applied the clock pulses. When the clock is low, transistor 102 conducts and the databus is charged essentially to the potential of the positive bus of the power supply.
At node 105 where data is to be transferred to the databus from the logic network 106, there is included an appropriate coupling network. This network comprises the p-type transistor 107 and n-type transistor 108 having their main conduction channels serially connected between the positive and negative buses 103 and 110, respectively, of the power supply. The node between the drain of transistor 107 and the drain of transistor 108 is connected to coupling node 105. The gates of transistors 107 and 108 are connected together and to the output of the AND gate 112. For reasons discussed before, preferably driver pull-up 107 should have a small beta while pull-down driver 108 should have a beta comparable to that of precharging transistor 102. AND gate 112 is supplied at one input with data from the logic network 106 and at the other input with the output of AND gate 114. This gate has as one input the clock from clock line 104 and as another input an enabling pulse from an enabling line 115 from a suitable control circuit (not shown) which provides an enabling pulse to AND gate 114 when data from network 106 is to be coupled to the databus.
In operation, when the clock is low, the outputs of both AND gates 112 and 113 are low, transistor 107 conducts, and transistor 108 is off. As a result the databus remains high. When the clock is high and an enabling pulse is supplied to AND gate 114, the output of the logic network determines the effect on the databus. When the output is low, there is no effect. When the output is high, transistor 108 conducts but transistor 107 is off whereby the databus is pulled down essentially to the low potential of power supply bus 110. It should be evident that the role of the two AND gates 112 and 114 can be combined in a single AND gate with three inputs: the clock pulse, the enabling pulse, and the data stream.
It should at this point be evident that a variety of other coupling arrangements can be provided at each of the nodes to couple controllably their data into the databus.
It is of course evident that, in a typical system, it will be important to couple the output of a plurality of logic networks to a common databus. FIG. 3 illustrates such an arrangement in which logic networks 201, 202, and 203 are coupled to a common databus 204 at nodes 205, 206, and 207, respectively. To this end there is inserted between the output of each logic network and its coupling node a coupling network or buffer 208, 209, or 210, of the kind described in connection with either FIG. 1 or FIG. 2. Each of the buffers is controlled by a common source of clock pulses 211 and a controller 212 which provides the enabling pulses which select the logic network to be effectively coupled to the databus at a particular time. Typically, the various logic networks will be connected sequentially in a prescribed order to the databus in successive clock cycles as indicated schematically by line 213. A single p-type transistor 214 under control of the clock pulses serves to precharge the databus for each of the coupling networks.
It can be appreciated that the databus is bidirectional in that pulses applied to the bus will propagate in both directions. However, each of the coupling arrangements is asymmetric in that pulses applied to the databus at one node will not transfer out by way of a coupling arrangement of the kind described at a different node. It would be, of course, feasible to design a coupling arrangement which would be symmetric if this were desired for some special purpose.
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To improve the speed of transfer of information to the databus in data processing apparatus, the bus is periodically precharged and the coupling to the databus is by way of a special clocked CMOS buffer circuit.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a lens system suitable for film camera, a television camera, a video camera or the like for performing image blur correction caused by vibration or fluctuation due to the hand vibration or wind by using an optical image blur correction optical system such as a shift lens (an image blur correction lens moving in a vertical direction to an image taking optical shaft) that is moved in a direction perpendicular to an optical axis of an image taking optical system or a variable apex angle prism (variable angle prism, VAP) or the like and a camera system composed of a camera provided with the lens system.
2. Related Background Art
In a conventional zoom lens having fluctuation preventing function, an optical image blur correction optical system is controlled so as to correct the vibration or fluctuation such as hand vibration detected by a fluctuation detection means so that the control of the image blur on the image forming plane is performed. In such a fluctuation preventing zoom lens, since the fluctuation or vibration such as hand vibration detected by the fluctuation detection means is corrected irrespective of the intention of the operator, and, the correction is effected for the vibration generated when the lens is moved in the horizontal direction or in the vertical direction, i.e., in so-called panning or tilting so that the operator determines the frame for the image pickup. There is a problem on the image taking operation when the frame is determined by the operator. Therefore, there has been an approach to effect the correction by judging the vibration generated when the operator performs the panning or tilting and the vibration such as hand vibration or the like generated irrespective of the operator's intention. For example, in Japanese Patent Application Laid-open No. 4-86735 (Japanese Patent Application No. 2-201183: U.S. Pat. No. 5,229,603), in an angular shift meter for detecting an angular shift of vibration generated in the camera, the vibration detection characteristics, particularly, the vibration detection frequency band of the angular shift meter are changed in accordance with the angular shift output of the angular shift meter. Namely, the vibration amplitude (angular shift) falls within a predetermined range in case of the normal hand vibration, whereas there is a large angular shift in the operation such as panning, and the judgement as whether the vibration is caused by the intentional operation or not is performed in accordance with the magnitude of the generated angular shift, thereby obtaining the optimum vibration detection characteristics of the sensor, i.e., image blur correction characteristics in accordance therewith.
However, a zoom lens has a focal length converting optical system that is detachable and called an extender separated from the zoom optical system and an angle of view on the image may be largely changed by attachment or detachment of the extender. Namely, in the case where the extender having the conversion magnification ratio of k times is inserted, the view angle after the insertion is 1/k of the view angle before the insertion. In such a case, when the panning is or the like is effected, since the ratio of the vibration, generated by the panning or the like, to the view angle is changed to k times by the insertion of the extender, the movement of the image field could not follow the intention of the cameraman, and there is a problem in that he or she feels something different.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a lens system that may suppress a strange feeling to the cameraman generated due to the difference in conversion ratio of a focal length converting optical system in panning and/or tilting and to provide a camera system provided with the lens system.
In order to attain this and other objects, according to the present invention, there is provided a lens system comprising:
an image taking optical unit having an optical axis;
a correction optical component for tilting the optical axis of the image taking optical unit;
a conversion optical component insertable into or retractable from the optical axis of the image taking optical unit;
a vibration sensor for detecting a vibration;
a insertion or retraction detection sensor for detecting whether the conversion optical component is disposed on the optical axis of the image taking optical unit or not;
a driver for driving the correction optical component to tilt the optical axis of the image taking optical unit; and
a controller for controlling the drive of the correction optical component by the driver in response to the detection output from the vibration sensor, characterized in that:
when the detection output from the vibration sensor exceeds a predetermined limit value, the controller controls the drive of the driver so that the correction optical component is located in the vicinity of the optical axis; and
the controller changes the limit value in correspondence with the output from the insertion or retraction detection sensor.
Also, according to the present invention, there is provided a lens system comprising:
an image taking optical unit having an optical axis;
a correction optical component for tilting the optical axis of the image taking optical unit;
a shift sensor for detecting a shift amount of the correction optical component;
a conversion optical component insertable into or retractable from the optical axis of the image taking optical unit;
a vibration sensor for detecting a vibration;
a insertion or retraction detection sensor for detecting whether the conversion optical component is disposed on the optical axis of the image taking optical unit or not;
a driver for driving the correction optical component to tilt the optical axis of the image taking optical unit; and
a controller for controlling the drive of the correction optical component by the driver in response to the detection output from the vibration sensor, characterized in that:
when the detection output from the shift sensor exceeds a predetermined limit value of the shift amount, the controller controls the drive of the driver so that the correction optical component is located in the vicinity of the optical axis; and
the controller changes the limit value in correspondence with the output from the insertion or retraction detection sensor.
Note that other structures and objects of the present invention will be apparent in th e description of the following embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing an arrangement of an optical system of a vibration preventing zoom lens system in accordance with a first embodiment of the present invention;
FIG. 2 is a block diagram showing a structure of a camera system in accordance with the first embodiment of the present invention;
FIG. 3 is a data table of correction coefficients with respect to the vibration angle in the yaw direction in accordance with the first embodiment of the present invention;
FIG. 4 is a flowchart showing the operation control in the yaw direction in accordance with the first embodiment of the present invention;
FIG. 5 is a data table of correction coefficients with respect to the vibration angle in the pitch direction in accordance with the first embodiment of the present invention;
FIG. 6 is a flowchart showing the operation control in the pitch direction in accordance with the first embodiment of the present invention; and
FIG. 7 is a flowchart showing the operation control in the yaw direction in accordance with a second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
FIG. 1 shows an arrangement of an optical system in accordance with one embodiment of the present invention, that is an example in which a focal length converting optical system (hereinafter, referred to as an extender) IE is located closer to the image side than an image blur correction optical system (correction optical system) IS. F denotes a focus lens group having a negative refractive power as a first lens group. V denotes a variator as a second lens group having a negative refractive power for varying of magnification of lens power (zooming) and moves to the image side along the image taking optical axis so as to perform the zooming from a wind angle end to a telephoto end. C denotes a compensator having a negative refractive power and moves reciprocatingly along the image taking optical axis for compensating for the change of a image plane in accordance with the zooming operation. A zoom optical system is composed of the variator V and the compensator C. SP denotes an aperture stop diaphragm. R denotes a relay lens group having a positive refractive power and fixed. IS denotes an image blur correcting optical system shown as a shift lens moving in a flat plane substantially vertically to the image taking optical axis for compensating the image blur when the overall system is vibrated. IE denotes an extender having extender optical systems different converting magnification ratio (2 times, 1.5 times, 1 time, 0.8 times, or the like). The extender optical systems are exchanged on the image taking optical axis to change the overall focal length to the telephoto side or wide angle side. Incidentally, air, a flat glass, a lens or the like may be used to constitute the focal length converting optical system having one time (extender optical system). In this case, the air means the condition that the extender optical system is retracted away from the image taking optical axis or the condition that the portion of through-hole as the extender optical system is disposed on the image taking optical axis. The image blur correction optical system IS and the extender IE are included in the relay lens group R. P denotes a chromatic decomposition optical system or an optical filter indicated by a glass block in FIG. 1 .
In FIG. 1, the image blur correction optical system IS is located closer to the image side than the zoom optical system V and C but it is possible to apply the present invention to the case where the image blur correction system IS is located closer to the object side.
FIG. 2 is a block diagram of a camera system suitable for broadcasting, composed of a video camera and the fluctuation preventing zoom lens system according to one embodiment of the present invention.
Explaining the scheme of the system referring to FIG. 2, reference numeral 50 denotes a fluctuation preventing zoom lens system, and numeral 51 denotes a video camera. A microcomputer 9 is provided in the fluctuation preventing zoom lens system 50 and a microcomputer 52 is provided in the video camera 51 , respectively. The microcomputer 52 and the microcomputer 9 perform the serial communication to thereby perform the signal exchange between the camera and the lens. Also, the image formed by the fluctuation preventing zoom lens system 50 is focused on a CCD 55 as an image sensor of the video camera 51 . The image sensor is not always the CCD. Charges are read out from the CCD 55 in order. The charges pass through an image signal processing circuit 54 and thereafter are outputted to the outside of the system as an image signal through an image output circuit 53 .
The internal structure of the fluctuation preventing zoom lens system 50 will now be described. Reference numeral 35 denotes a zoom optical system for zooming, numeral 36 denotes a positional detector for detecting the zoom position of the zoom optical system 35 , numeral 37 denotes an A/D converter, and numeral 38 denotes a zoom operating member for operating the zoom optical system 35 .
Furthermore, numeral 39 denotes a focusing lens group for focusing, numeral 40 denotes a positional detector for detecting the focus position of the focusing lens group 39 , numeral 41 denotes an A/D converter, and numeral 42 denotes a focus operating member for operating the focusing lens group 39 . With such an arrangement, the operator operates the zoom operating member 38 so that the zoom optical system 35 moves along the image taking optical axis to make it possible to perform the zooming operation. The zoom position of the zoom optical system 35 is detected by means of the position detector 36 to always output the zoom position signal. This outputted zoom position signal is converted into a digital signal by the A/D converter 37 and inputted into the microcomputer 9 . In the same manner, the operator operates the focus operating member 42 so that the focus lens group 39 moves along the image taking optical axis to thereby make it possible to perform the focusing operation. The focus position of the focus lens group 39 is detected by means of the position detector 40 to always output a focus position signal. This outputted focus position signal is converted into a digital signal by means of the A/D converter 41 and inputted into the microcomputer 9 .
The extender is disposed in the fluctuation preventing zoom lens system 50 . Numeral 43 denotes an extender changeover switch, numeral 44 denotes a motor for switching the attachment or detachment of the extender, numeral 45 denotes an extender holder member for holding the extender, numeral 46 denotes a first extender having a converting magnification ratio of one time (1×), and numeral 47 denotes a second extender having a converting magnification ratio of two times (2×). Numeral 48 denotes a position detector for detecting the extender. The extender changeover switch 43 outputs an extender switching signal corresponding to the extender 46 or 47 to be inserted into the image taking optical axis and the signal is inputted into the microcomputer 9 . In the microcomputer 9 , the motor 44 is driven in accordance with the extender switching signal to rotate the extender holder member 45 and at the same time supervises the positional signal of the extender outputted from the position detector 48 to move the extender 46 or 47 selected by the extender switch 43 into the position on the image taking optical axis to thereby perform the exchange of the extenders.
The structure related to the image blur correction will now be described. Numeral 1 denotes a yaw angular velocity sensor for detecting a horizontal vibration of the fluctuation preventing zoom lens system 50 , numeral 2 denotes a high pass filter for separating only a high frequency component out of a signal inputted, numeral 3 denotes a low pass filter for separating a low frequency component out of the signal inputted, numeral 4 denotes an analog switch (signal switcher) for perform the exchange of signals, numeral 5 and 6 high pass filters, 7 denotes an integrator, numeral 8 denotes an A/D converter for converting the analog signal into a digital signal, numeral 9 denotes a microcomputer for calculating the output signal and processing the input signal, numeral 10 denotes a D/A converter for converting the digital signal into an analog signal, numeral 11 denotes a subtractor for subtracting the analog signal, numeral 12 denotes a phase compensation circuit for compensating the phase of a frequency component of the analog signal inputted, numeral 13 denotes a subtractor, numeral 14 denotes an amplifier circuit for amplifying an electric power of the inputted signal, numeral 15 denotes a motor for driving horizontally the image blur correction optical system for compensating for the image blur in the yaw direction, numeral 16 denotes a current detection circuit for detecting a magnitude of the current to be fed to the motor 15 , numeral 17 denotes the image blur correcting optical system for correcting a tilt of the image taking optical axis, and numeral 18 denotes a position detector for detecting the horizontal position of the image blur correcting optical system 17 . The components from the yaw angular velocity sensor 1 to the position detector 18 constitute a servo system for performing the horizontal control of the image blur correcting optical system 17 .
In the same manner, numeral 19 denotes a pitch angular velocity sensor for detecting an angular velocity of a vertical vibration of the fluctuation preventing zoom lens system 50 , numeral 20 denotes a high pass filter for separating only a high frequency component out of a signal inputted, numeral 21 denotes a low pass filter for separating a low frequency component out of the signal inputted, numeral 22 denotes an analog switch (signal switcher) for perform the exchange of signals, numeral 23 and 24 denote high pass filters, 25 denotes an integrator, numeral 26 denotes an A/D converter for converting the analog signal into a digital signal, numeral 27 denotes a D/A converter for converting the digital signal into an analog signal, numeral 28 denotes a subtractor for subtracting the analog signal, numeral 29 denotes a phase compensation circuit for compensating the phase of a frequency component of the analog signal inputted, numeral 30 denotes a subtractor, numeral 31 denotes an amplifier circuit for amplifying an electric power of the inputted signal, numeral 32 denotes a motor for driving vertically the image blur correction optical system 17 for compensating for the image blur in the pitch direction, numeral 33 denotes a current detection circuit for detecting a magnitude of the current to be fed to the motor 32 , and numeral 34 denotes a position detector for detecting the vertical position of the image blur correcting optical system 17 . The components from the pitch angular velocity sensor 19 to the position detector 34 constitute a servo system for performing the vertical control of the image blur correcting optical system 17 .
Also, numeral 49 denotes a fluctuation preventing selection switch for allowance or prohibition of the image blur correction in the yaw direction and the pitch direction. This switch is operated so that the prohibition of the correction of the image blur correction in the yaw direction or the correction of the image blur correction in the pitch direction may be selected. Numeral 56 denotes a limit value stay limit time input member for inputting a limit value stay limit time for judging the panning or the tilting to be described later. Numeral 57 denotes a centering time input member for inputting a period of time for returning the correction optical system 17 back to the standard position in the vicinity of and including the image taking optical axis (a predetermined centering position and the position when the angular shift position that is the output of the integrators 7 and 25 is at zero.) in the punning operation or the tilting operation.
The operation of the servo system in the yaw direction composed of the components from the yaw angular velocity sensor 1 to the position detector 18 will first be described referring to FIG. 2 . The vibration signal in the yaw direction detected by the yaw angular velocity sensor 1 passes through the high pass filter 2 so that the signal component of the low frequency such as a swing is removed and further passes through the low pass filter 3 to become the signal that is free from the adverse affect such as noise in the left signal component. It is therefore possible to pick up the signal component having a necessary band. The picked-up signal passes through the analog switch 4 controlled by the microcomputer 9 to be outputted to either high pass filter 5 or 6 . The high pass filters 5 and 6 are the high pass filters having the different frequency bands. The filter 5 and the filter 6 are the high pass filters having the necessary bands for the normal control and the special control such as the case where the operation is judged as the panning condition or the like to be described later, respectively. The microcomputer 9 switches over the analog switch 4 so that the high pass filter having the necessary band may be suitably selected to obtain the band needed for the control. The signal outputted from the high pass filter 5 or 6 is inputted into the integrator 7 . The integrator 7 integrates the yaw angular velocity signal to output an angular signal representative of the magnitude of the shift angle in the yaw direction. The outputted angular signal is converted into a digital signal through the A/D converter 8 and inputted into the microcomputer 9 .
In the microcomputer 9 , if the output of the fluctuation preventing selection switch 49 allows the image blur correction in the yaw direction, the command value in the yaw direction of the image blur correction optical system 17 is calculated and outputted to the D/A converter 10 where the command value in the yaw direction outputted as a digital signal is converted into the analog signal and outputted into the subtractor 11 . In the latter, the difference between the command value in the yaw direction outputted from the D/A converter 10 and the actual position in the yaw direction of the image blur correcting optical system 17 outputted from the position detector 18 is calculated b the subtractor 11 and the error in the position in the yaw direction is outputted. The amount of the outputted error in the position in the yaw direction is subjected to the phase compensation so as to be controllable in the frequency band in the yaw direction needed in controlling in the phase compensation circuit 12 and thereafter is outputted to the subtractor circuit 13 where the subtraction is effected between this phase compensated signal and the output signal of the current detector circuit 16 for detecting the current to be fed to the motor 15 for driving in the yaw direction and the difference therebetween is outputted to the amplifier circuit 14 . The amplifier circuit 14 performs the electric power amplification while using the inputted signal to drive the motor 15 for driving in the yaw direction of the image blur correcting optical system 17 . In the yaw direction driving motor 15 drives the image blur correcting optical system 17 in the yaw direction in accordance with the inputted signal. Thus, in the servo system composed of the components from the yaw angular velocity sensor 1 to the position detector 18 , the fluctuation in the yaw direction is detected, and the position command value of the image blur correcting optical system 17 needed in correcting the detected vibration signal in the yaw direction is calculated by the microcomputer 9 to form position controlling feedback loop circuit for driving the image blur correcting optical system 17 in the yaw direction in accordance with this positional command value.
The operation of the microcomputer 9 will now be described. In the microcomputer 9 , the amount of movement (the amount of correction) in the yaw direction of the image blur correcting optical system 17 is calculated in accordance with a data table calculated in advance by using as parameters the yaw angle signal inputted, the zoom position signal of the zoom optical system 35 for zooming and the focus position signal of the focus lens group 39 that is an optical system for focusing. This data table is shown in FIG. 3 . With respect to the correction coefficients AOO to AOn in FIG. 3, the maximum image shift amount ΔYMAX at a certain zoom ratio Z is determined to meet the following relationship:
0.8≦( Z/ZT )/(Δ YMAXT/ΔYMAX )≦1.2 (1)
where ΔYMAX is the maximum image shift amount which is capable of being corrected by the image blur correcting optical system 17 , ZT is the magnification ratio of the zoom lens optical system 35 at the telephoto side end and ΔYMAXT is the maximum image shift amount at the telephoto side end. Thus, it is possible to keep substantially constant the maximum fluctuation angle which is capable of being corrected by the image blur correcting optical system 17 . In FIG. 3, the correction coefficients of the image blur correcting optical system 17 for the fluctuation angle (angle signal) in the yaw direction are represented as Axx (x=0, 1, 2, . . . , n). The data table of FIG. 3 is composed of the correcting coefficients Axx corresponding to the zoom positions and the focus positions. In this case, in the zoom positions, the values from the position detector 36 are normalized, the value at the wide side end is represented by zero and the value at the telephoto side end is represented by a 16-notation system as 0xffff. In the focus position, the focus position from the position detector 40 are normalized, the value at the close side end is represented by zero and the value at the infinite side end is represented by a 16-notation system as 0xffff.
In the microcomputer 9 , the above-described data table is used and the inputted angle signal in the yaw direction is multiplied by the correction coefficient of the data table to thereby calculate the correction amount of the image blur correcting optical system 17 and output the data to the D/A converter 10 as the position command value of the image blur correcting optical system 17 .
Herein, the limit value of the detection signal (angle signal) of vibration for shifting the image blur correcting optical system 17 to the standard position in the vicinity of and including the image taking optical axis will now be described.
When the vibration angle of the image taking optical system is represented by θ and the focal length of the zoom optical system is represented by f, the image shift amount ΔY for the infinite object is:
Δ Y=f ·tanθ (2).
Then, the maximum image shift amount YMAX which is capable of being corrected by the image blur correcting optical system 17 is:
Δ YMAX=f ·tanθ MAX (3)
Where θMAX is the image blur correctable maximum vibration angle.
Also, when the focal length converting optical system (extender) having the conversion ratio of k times is inserted into the image taking optical axis, the maximum image shift amount is represented by:
Δ YMAX=k·f ·tanθ MAX (4)
In the equation (3), the maximum vibration angle θ MAX determined by imparting the maximum image shift amount ΔYMAX at the telephoto side end at the conversion ratio of one time so that the maximum image shift amount ΔYMAX is changed depending upon the focal length f from the equation (3). It is necessary to keep the maximum image shift amount ΔYMAX unchanged even if the focal length converting optical system is inserted because the cameraman does not feel something different. In this case, in the equation (4), the maximum vibration angle θMAX determined by imparting the same value in the above-described case at the ratio of one time as the maximum image shift amount ΔYMAX at the telephoto side end at the conversion ratio of k times is kept constant so that the maximum image shift amount ΔYMAX is changed depending upon the focal length f from the equation (4).
According to the present invention, the limit value corresponding the maximum vibration angle θMAX within which the image blur may be corrected as the judging level for judging the panning, tilting or the like is set, and this limit value is changed in correspondence with the conversion ratio k of the focal length converting optical system to be inserted into the image taking optical axis.
The above-described change in the limit value may be obtained by the calculation of the computer 9 every time, or the limit value data table provided by limit values determined in advance may be stored as the data table in the internal memory of the computer 9 or the memory provided outside for obtaining the limit value.
Incidentally, in the foregoing embodiment, the case where the panning and the tilting may be judged from the angle signal has been described. However, it is possible to judge the panning and tilting from the shift amount ΔS of the image blur correcting optical system.
The shift amount ΔS of the image blur correcting system for off-setting the image shift amount ΔY is represented by the following equation:
ΔS=−ΔY/dy (5)
where dy is the image shift sensitivity of the image blur correcting optical system. However, in the case where the image blur correcting optical system is located closer to the image side than the zoom optical system V, C, the image shift sensitivity dy is kept constant, and in the case where image blur correcting optical system is located closer to the object side, the image shift sensitivity is not kept constant but may change depending upon the condition of the optical system disposed closer to the image side than the image blur correcting optical system.
According, from the above-described equations (3) and (4), the maximum shift amount ΔSMAX of the image blur correcting optical system is:
Δ SMAX=−ΔYMAX/dy=−f ·tanθ MAX/dy (6)
ΔSMAX=−ΔYMAX/dy=−k·f·tanθ MAX/dy (7)
Therefore, in order to judge the panning, tilting from the shift amount ΔS of the image blur correcting optical system, it is sufficient to set the value of the limit change amount corresponding to the maximum shift amount ΔSMAX of the image blur correcting optical system, and at the same time, to change the value of this limit change amount in correspondence with the image shift sensitivity dy from the focal length f (i.e., the zoom position of the zoom optical system) and the conversion ratio k of the focal length converting optical system to be inserted into the image taking optical axis.
The above-described limit value change may be obtained by the calculation of the computer 9 every time, or may be obtained by using the data table of these limit change amount values while the predetermined limit change amount values are stored in the internal memory or the outside memory.
If the angular signal in the yaw direction inputted through the A/D converter 8 is located in the position beyond the limit value for the longer period of limit time inputted from the limit value stay limit time input member 56 , the microcomputer 9 judges that the panning is performed and shifts to the panning operation controlling mode upon the judgement of the panning. Namely, the analog switch 4 is switched over, and the signal is switched over so that the output of the low pas filter 3 is inputted into the high pass filter 6 for the panning operation. Since the high pass filter 6 has a high interrupt frequency in comparison with that of the high pass filter 5 and the interrupt frequency is set so that the input signal is gradually attenuated, the output signal of the high pass filter 6 is a signal of zero representative of the condition of the no vibration. Also, at the same time, the microcomputer 9 outputs the signal to the integrator 7 to change of the integrating time constant and to discharge. The integrator 7 is controlled to be returned back to the reference condition with the zero output in accordance with this signal, as a result of which the angular signal in the yaw direction outputted from the integrator 7 is returned back to the reference condition, i.e., attenuated to zero. Incidentally, the integration time constant in this case is changed to thereby make it possible to control the period of time for returning back to the reference condition. In the microcomputer 9 , since under the condition that the inputted angular signal in the yaw direction is at zero, the correction amount of the image blur correcting optical system 17 is at zero, i.e., under the condition that is equal to the condition that the compensation is not effected, the image blur correcting optical system 17 is moved to the reference position (centering position) where the correction amount is at zero. When the microcomputer 9 judges that the output of the A/D converter 8 is under the reference condition, the analog switch 4 is again switched over. The microcomputer 9 inputs the signal to the high pass filter 5 and at the same time interrupts the signal output to the integrator 7 for the normal operation.
Furthermore, in the case where the extender having the conversion ratio k is inserted, the limit value for the angular signal in the yaw direction corresponding to the conversion ratio k is set. For instance, the limit value Is set at 1/k and the judgement is performed in comparison with the case of the conversion ratio of one time so that the mode is shifted to the panning operation controlling mode at a smaller vibration angle in comparison with, for example, the case where the extender 46 (conversion ratio 1×) is inserted.
Incidentally, in the case where the operational mode is switched to the condition that no extender is provided (i.e., the conversion ratio of one time) and the condition that the extender having the conversion ratio k is inserted, the presence/absence of the extender is detected. When the presence is detected, it is possible to set the limit value to a small value, for example, 1/k.
Thus, the limit value of the vibration for shifting the panning operation control mode is changed in accordance with a kind (conversion ratio) of the extender, the change of the correctable vibration on the image generated by the attachment or detachment of the extender is obviated so that the image blur correction is possible without any unusual feeling due to the difference in size of the correctable vibration.
The operation of the above-described microcomputer 9 is represented by the flowchart of FIG. 4 . The microcomputer 9 performs the process shown in this flowchart for a constant period of time. In the vibration angle input process in the first step S 1 , the data into which the outputs of the integrator 7 are converted by the A/D converter 8 are inputted. In step S 2 , the determination is performed by means of a flag as to whether the panning operation control is performed or the normal operation control is performed. The operation goes to the respective control steps. In the normal operation, in step S 3 , the position of the extender is picked up, the kind (conversion magnification) of the extender currently inserted into the image taking optical axis is determined, and the limit value of the vibration angle for shifting to the panning operation control is set to a predetermined value in accordance with the kind of the extender. In step S 4 , the magnitude of the vibration angle inputted at step S 1 and the limit value of the vibration angle set in step S 3 are compared with each other. If the vibration angle is smaller than the limit value, since it is unnecessary to shift the operational mode to the panning operation control, the counter (since the operation in the flowchart shown in FIG. 4 is periodically performed at a constant interval, the number of the cycles of the flowchart is counted by the counter to measure the period of time) representative the period of time for staying at the limit value of the vibration angle is cleared. Thereafter, in step 11 , the data table is used to calculate the correction amount from the inputted vibration angle. The result calculated in the step S 12 is outputted to the D/A converter 10 .
On the other hand, in step S 4 , in the case where the vibration angle exceeds the limit value, the operational mode goes to the step S 6 and the counter representative of the period of time for which the vibration angle stays beyond the limit value is incremented by +1. Furthermore, the limit time inputted by the limit value stay limit time input member 57 is read out in step S 7 . In step S 8 , the set limit time and the counter value are compared with each other. If the counter value does not reach the limit time, at the present it is determined that it is unnecessary to shift the operational mode to the panning operation control. The correction amount is calculated from the input vibration angle in step S 11 . The result calculated in the step S 12 is outputted to the D/A converter 10 . In the case where it is judged that the counter value exceeds the limit time is step S 8 , in step S 9 , the panning operation control is initialized. Namely, since the operational mode shifts to the panning operation control, the output of the analog switch 4 is switched to the high pass filter 6 , and at the same time, the control is effected so that the output of the integrator 7 comes to the reference condition. In step S 10 , after the flag for determination of the performance of the panning operation control is set and the counter representative of the time for which the vibration angle stays beyond the limit value is cleared. After that, the next operational control goes to the step S 11 where the correction amount is calculated from the inputted vibration angle. The result calculated in the step S 12 is outputted to the D/A converter 10 . The above-described consecutive steps are the flowchart for the normal operational control.
The operational control flowchart of the panning operation will now be described. In the step S 13 subsequent to the flowchart branched from the banning operation in accordance with the banning operation determination flag, a time period for centering is set in accordance with the input from the centering time input member 57 . In step S 14 , the control of the integrator 7 is performed using the period of time for centering as a parameter. Namely, the integrator 7 is controlled so that the output becomes the reference condition, as a result of which the angle signal in the yaw direction outputted from the integrator 7 is attenuated to the reference condition, i.e., zero. In the next step S 15 , the input vibration angle and the reference position (centering position) are compared with each other. If the input vibration angle reaches the reference position, in step S 16 , in order to finish the panning operation control, the output of the analog switch 4 is switched to the high pass filter 5 . Furthermore, the control of the integrator 7 is finished, and in step S 17 , the panning operation determination flag is cleared up. Then, the correction amount is calculated from the input vibration angle in step S 11 . The result calculated in step S 12 is outputted to the D/A converter 10 . Unless the input vibration angle reaches the reference position, in order to continue the panning operation control in the next cycle, the operation goes from the step S 15 to step S 11 so that the panning operation determination flag is not cleared up. The correction amount is calculated from the input vibration angle. The result calculated in step S 12 is outputted to the D/A converter 10 . The control flowchart in the case where the blur image correction in the yaw direction is allowed has been described above.
The like system is formed in the pitch direction. Namely, the vibration signal in the pitch direction detected by the pitch angular velocity sensor 19 passes through the high pass filter 20 so that the signal component of the low frequency such as a swing is removed and further passes through the low pass filter 21 to become the signal that is free from the adverse affect such as noise in the left signal component. It is therefore possible to pick up the signal component having a necessary band. The picked-up signal passes through the analog switch 22 controlled by the microcomputer 9 to be outputted to either high pass filter 23 or 24 . The high pass filters 23 and 24 are the filters having the different frequency bands. The filter 23 and the filter 24 are the high pass filters having the necessary bands for the normal control and the special control such as the case where the operation is judged as the tilting condition or the like respectively, similar to the case of the panning condition described above. The microcomputer 9 switches over the analog switch 22 so that the high pass filter having the necessary band may be suitably selected to obtain the band needed for the control. The signal outputted from the high pass filter 23 or 24 is inputted into the integrator 25 . The integrator 25 integrates the pitch angular velocity signal to output an angular signal representative of the magnitude of the shift angle in the pitch direction. The outputted angular signal is converted into a digital signal through the A/D converter 26 and inputted into the microcomputer 9 .
In the microcomputer 9 , if the output of the fluctuation preventing selection switch 49 allows the image blur correction in the pitch direction, the command value in the pitch direction of the image blur correction optical system 17 is calculated and outputted to the D/A converter 27 where the command value in the pitch direction outputted as a digital signal is converted into the analog signal and outputted into the subtractor 28 . In the latter, the difference between the command value in the pitch direction outputted from the D/A converter 27 and the actual position in the pitch direction of the image blur correcting optical system 17 outputted from the position detector 34 is calculated by the subtractor 28 and the error in the position in the pitch direction is outputted. The amount of the outputted error in the position in the pitch direction is subjected to the phase compensation so as to be controllable in the frequency band in the pitch direction needed in controlling in the phase compensation circuit 29 and thereafter is outputted to the subtractor circuit 30 where the subtraction is effected between this phase compensated signal and the output signal of the current detector circuit 33 for detecting the current to be fed to the motor 32 for driving in the pitch direction and the difference therebetween is outputted to the amplifier circuit 31 . The amplifier circuit 31 performs the electric power amplification while using the inputted signal to drive the motor 32 for driving in the pitch direction of the image blur correcting optical system 17 and amplified signal is input into the motor 32 . In the pitch direction driving motor 32 drives the image blur correcting optical system 17 in the pitch direction in accordance with the inputted signal. Thus, in the servo system composed of the components from the pitch angular velocity sensor 19 to the position detector 34 , the fluctuation in the pitch direction is detected, and the position command value of the image blur correcting optical system 17 needed in correcting the detected vibration signal in the pitch direction is calculated by the microcomputer 9 to form position controlling feedback loop circuit for driving the image blur correcting optical system 17 in the pitch direction in accordance with this positional command value.
In the same manner as in the case in the yaw direction, the operation of the microcomputer 9 will now be described. In the microcomputer 9 , the amount of movement (the amount of correction) also in the pitch direction of the image blur correcting optical system 17 is calculated in accordance with a data table calculated in advance as shown in FIG. 5 by using as parameters the pitch angle signal inputted, the zoom position signal of the zoom optical system 35 for zooming and the focus position signal of the focus lens group 39 that is an optical system for focusing. The data table of FIG. 5 is calculated in the same manner as in the yaw direction. The maximum vibration angle in the pitch direction correctable by the image blur correcting optical system 17 is kept substantially constant. In FIG. 5, the correction coefficients of the image blur correcting optical system 17 for the fluctuation angle in the pitch direction are represented as Bxx (x=0, 1, 2, . . . , n). The data table of FIG. 5 is composed of the correcting coefficients Bxx corresponding to the zoom positions and the focus positions. In this case, in the zoom positions, the values from the position detector 36 are normalized, the value at the wide side end is represented by zero and the value at the telephoto side end is represented by a 16-notation system as 0xffff. In the focus position, the focus position from the position detector 40 are normalized, the value at the close side end is represented by zero and the value at the infinite side end is represented by a 16-notation system as 0xffff.
In the microcomputer 9 , the above-described data table is used and the correction amount of the image blur correcting optical system 17 is calculated from the inputted angle signal in the pitch direction and outputted to the D/A converter 27 as the position command value of the image blur correcting optical system 17 .
Also, if the angular signal in the pitch direction inputted through the A/D converter 26 is located in the position beyond the limit value for the longer period of limit time inputted from the limit value stay limit time input member 56 , the microcomputer 9 judges that the tilting is performed and shifts to the tilting operation controlling mode upon the judgement of the tilting. Namely, the analog switch 22 is switched over, and the signal is switched over so that the output of the low pas filter 21 is inputted into the high pass filter 23 for the tilting operation. Since the high pass filter 24 has a high interrupt frequency in comparison with that of the high pass filter 23 and the interrupt frequency is set so that the input signal is gradually attenuated, the output signal of the high pass filter 24 is a signal of zero representative of the condition of the no vibration. Also, at the same time, the microcomputer 9 outputs the signal to the integrator 25 to change of the integrating time constant and to discharge. The integrator 25 is controlled to be returned back to the reference condition with the zero output in accordance with this signal, as a result of which the angular signal in the pitch direction outputted from the integrator 25 is returned back to the reference condition, i.e., attenuated to zero. Incidentally, the integration time constant in this case is changed to thereby make it possible to control the period of time for returning back to the reference condition. In the microcomputer 9 , since under the condition that the inputted angular signal in the pitch direction is at zero, the correction amount of the image blur correcting optical system 17 is at zero, i.e., under the condition that is equal to the condition that the compensation is not effected, the image blur correcting optical system 17 is moved to the reference position (centering position) where the correction amount is at zero. When the microcomputer 9 judges that the output of the A/D converter 26 is under the reference condition, the analog switch 22 is again switched over. The microcomputer 9 inputs the signal to the high pass filter 23 and at the same time interrupts the signal output to the integrator 25 for the normal operation.
Furthermore, in the case where the extender having the conversion ratio k is inserted, the limit value for the angular signal in the pitch direction corresponding to the conversion ratio k is set. For instance, the limit value is set at 1/k and the judgement is performed in comparison with the case of the conversion ratio of one time so that the mode is shifted to the tilting operation controlling mode at a smaller vibration angle in comparison with, for example, the case where the extender 46 (conversion ratio 1×) is inserted.
Thus, the limit value of the vibration for shifting to the tilting operation control mode is changed in accordance with a kind (conversion ratio) of the extender, whereby the change of the correctable vibration on the image generated by the attachment or detachment of the extender is obviated so that the image blur correction is possible without any unusual feeling on the image due to the difference in size of the correctable vibration.
The operation of the above-described microcomputer 9 is represented by the flowchart of FIG. 6 . The microcomputer 9 performs the process shown in this flowchart for a constant period of time. In the vibration angle input process in the first step S 21 , the data into which the outputs of the integrator 25 are converted by the A/D converter 26 are inputted. In step S 22 , the determination is performed by means of a flag as to whether the tilting operation control is performed or the normal operation control is performed. The operation goes to the respective control steps. In the normal operation, in step S 23 , the position of the extender is picked up, the kind (conversion magnification) of the extender currently inserted into the image taking optical axis is determined, and the limit value of the vibration angle for shifting to the tilting operation control is set to a predetermined value in accordance with the kind of the extender. In step S 24 , the magnitude of the vibration angle inputted in step 21 and the limit value of the vibration angle set in step S 23 are compared with each other. If the vibration angle is smaller than the limit value, since it is unnecessary to shift the operational mode to the tilting operation control, the counter (since the operation in the flowchart shown in FIG. 6 is periodically performed at a constant interval, the number of the cycles of the flowchart is counted by the counter to measure the period of time) representative the period of time for staying of the vibration angle at the limit value is cleared. Thereafter, in step 31 , the data table is used to calculate the correction amount from the inputted vibration angle. The result calculated in step S 32 is outputted to the D/A converter 27 .
On the other hand, in step S 24 , in the case where the vibration angle exceeds the limit value, the operation goes to the step S 26 and the counter representative of the period of time for which the vibration angle stays beyond the limit value is incremented by +1. Furthermore, the limit time inputted by the limit value stay limit time input member 57 is read out in step S 27 . In step S 28 , the set limit time and the counter value are compared with each other. If the counter value does not reach the limit time, at the present it is determined that it is unnecessary to shift the operational mode to the tilting operation control. The correction amount is calculated from the input vibration angle in step S 31 . The result calculated in the step S 32 is outputted to the D/A converter 27 . In the case where it is judged that the counter value exceeds the limit time in step S 28 , in step S 29 , the tilting operation control is initialized. Namely, since the operational mode shifts to the tilting operation control, the output of the analog switch 22 is switched to the high pass filter 24 , and at the same time, the control is effected so that the output of the integrator 25 comes to the reference condition. In step S 30 , after the flag for determination of the performance of the tilting operation control is set and the counter representative of the time, for which the vibration angle stays at the limit value until the completion of the shift to the tilting operation control, is cleared, the next operational control goes to the step S 31 where the correction amount is calculated from the inputted vibration angle. The result calculated in the step S 32 is outputted to the D/A converter 27 . The above-described consecutive steps are the flowchart for the normal operational control.
The operational control flowchart of the tilting operation will now be described. In the step S 33 subsequent to the flowchart branched from the tilting operation in accordance with the tilting operation determination flag, a time period for centering is set in accordance with the input from the centering time input member 57 . In step S 34 , the control of the integrator 25 is performed using the period of time for centering as a parameter. Namely, the integrator 25 is controlled so that the output becomes the reference condition after the elapse of the period of time for centering, as a result of which the angle signal in the pitch direction outputted from the integrator 25 is attenuated to the reference condition, i.e., zero. In the next step S 35 , the input vibration angle and the reference position (centering position) are compared with each other. If the input vibration angle reaches the reference position, in step S 36 , in order to finish the tilting operation control, the output of the analog switch 22 is switched to the high pass filter 23 . Furthermore, the control of the integrator 25 is finished, and in step S 37 , the tilting operation determination flag is cleared up. Then, the correction amount is calculated from the input vibration angle in step S 31 . The result calculated in step S 32 is outputted to the D/A converter 27 . Unless the input vibration angle reaches the reference position, in order to continue the tilting operation control in the next cycle, the operation directly goes from the step S 35 to step S 31 so that the tilting operation determination flag is not cleared up. The correction amount is calculated from the input vibration angle. The result calculated is outputted to the D/A converter 27 . The control flowchart in the case where the blur image correction in the pitch direction is allowed has been described.
Second Embodiment
In the first embodiment, in the panning operation control or in the tilting operation control, the control of the integrator 7 , 25 is changed so that the time until the output becomes the reference condition is controlled. However, the same effect as that of the first embodiment may be obtained by the following method. The integrator 7 , 25 is set to become the reference condition for a minimum period of time. A new low pass filter of software by the microcomputer 9 is provided. The interrupt frequency of the low pass filter may be changed by setting the centering time input member 57 . The reference position signal is given to the input of this low pass filter to perform the calculation of the low pas filter of software. The calculation result is regarded as an angle signal to perform the correction amount calculation.
If the above-described context is given in the form of the flowchart, it is shown in FIG. 7 . FIG. 7 shows the flowchart in the yaw direction but the flowchart in the pitch direction is similar thereto. FIG. 7 is different from FIG. 4 in steps S 41 to S 45 .
The microcomputer 9 performs the process shown in the flowchart for every constant interval. In the process of the vibration angle input of the first step S 1 , the data into which the output of the integrator 7 is converted by the A/D converter 8 is inputted. In step S 41 , the interrupt frequency of the low pass filter composed of software is determined in accordance with the input from the centering time input member 57 . In the case where the interrupt frequency is low, the centering time period is long. If the interrupt frequency is high, the centering time period is short. In step S 2 , the determination is conducted in accordance with the flag as to whether the panning operation control should be executed or the normal operation control should be executed, and the operation goes to the respective control steps. In the normal operation control, in step S 42 , the vibration angle is filter calculated by the low pass filter of the software. This calculation is conducted in order to keep the continuity of the values of the filter. In the normal operation control, the output of the filter calculation is not used. In step S 3 , the position of the extender is picked up, the kind (conversion magnification) of the extender currently inserted into the image taking optical axis is determined and the limit value for the vibration angle at which the operational mode goes to the panning operation control is suitably set according to the kind of the extender. For example, in the case where the extender having the conversion magnification k is inserted into the image taking optical axis, the limit value is set at 1/k.
Furthermore, in step S 4 , the magnitude of the vibration angle inputted and the limit value of the vibration angle set are compared with each other. If the vibration angle is smaller than the limit value, since it is unnecessary to shift the operational mode to the panning operation control, the counter representative of the period of time for which the vibration angle stays at the limit value is cleared up. Thereafter, in step S 11 , the data table of FIG. 2 is used to calculate the correction amount from the inputted vibration angle. The result calculated in the step S 12 is outputted to the D/A converter 10 .
On the other hand, in the case where the vibration angle exceeds the limit value, the counter representative of the period of time for which the vibration angle stays beyond the limit value is incremented by +1 in step S 6 . The limit time is read out and set in step S 7 . In step S 8 , the set limit time and the counter value are compared with each other. If the counter value does not reach the limit time, at the present it is determined that it is unnecessary to shift the operational mode to the panning operation control. The correction amount is calculated from the input vibration angle in step S 11 . The result calculated in the step S 12 is outputted to the D/A converter 10 .
In the case where the counter value exceeds the limit time, in step S 9 , since the operational mode shifts to the panning operation control, the output of the analog switch 4 is switched to the high pass filter 6 , and at the same time, the control is effected so that the output of the integrator 7 comes to the reference condition. In step S 10 , after the flag for determination of the performance of the panning operation control is set and the counter representative of the time for which the vibration angle stays beyond the limit value is cleared, the correction amount is calculated from the vibration angle inputted in step S 11 . The result calculated in the step S 12 is outputted to the D/A converter 10 . The above-described consecutive steps are the flowchart for the normal operational control.
The operational control flowchart of the panning operation will now be described. In the step S 43 subsequent to the flowchart branched from the panning operation in accordance with the banning operation determination flag, the value of the vibration angle to be inputted into the low pass filter composed of software is made a value representative of the reference position, and the filter calculation is performed. The output value of this low pass filter of t he software is gradually attenuated and finally reaches the reference position. This attenuation time is controlled so as to be identified with the set centering time. In the next step S 45 , the comparison of the output value of the low pass filter of the software with the reference value is conducted. In step S 16 , if the input vibration angle reaches the reference position, in order to finish the panning operation control, the output of the analog switch 4 is switched to the high pass filter 5 . Furthermore, the control of the integrator 7 is set to be ready for normal operation. In step S 17 , the panning operation determination flag is cleared up. Furthermore, the calculation of the correction amount is performed using as the input signal the output value of the low pass filter of software calculated in step S 11 . In step S 12 , the result calculated is outputted to the D/A converter 10 . Unless the input vibration angle reaches the reference position, the operation goes from the step S 45 directly to step S 12 so that the panning operation determination flag is not cleared up in order to keep the continuity of the panning control operation in the next operation. The calculation of the correction amount is performed using as the input signal the output value of the low pass filter of software calculated. The result calculated in step S 12 is outputted to the D/A converter 10 .
Third Embodiment
In the flowcharts shown in FIGS. 4, 6 and 7 , it is necessary to determine whether the vibration angle outputted from the integrator 7 , 25 is not less than the limit value and the counter value is not less than the limit time, i.e., whether the period of time when the vibration angle is within the limit value is longer than a predetermined period of time so as to meet the condition that the image blur correcting optical system 17 is shifted to the reference position including and in the vicinity of the image taking optical axis. However, it is possible to solely set the condition that the vibration angle outputted from the integrator 7 , 25 be not less than the limit value.
Incidentally, the data table shown in FIGS. 3 and 5 may be stored on the side of the video camera 51 .
Also, the zoom operation member 38 , the focus operation member 42 , the vibration preventing selection switch 49 , the limit value stay time input member 56 and the centering time input member 57 may be disposed on the side of the video camera 51 .
As described above, according to the present embodiment, the limit value of the detection signal of the vibration for shifting the image blur correcting optical system to the reference position including and in the vicinity of the image taking optical axis is changed in accordance with the absence or presence and/or the conversion magnification of the focal length converting optical system whereby upon panning or tilting, the strange feeling to the cameraman caused due to the difference of the conversion magnification of the focal length converting optical system may be suppressed.
Also, the limit shift amount of the detection signal of the shift amount of the image blur correcting optical system set for shifting the image blur correcting optical system to the reference position including and in the vicinity of the image taking optical axis is changed in accordance with the absence or presence and/or the conversion magnification of the focal length converting optical system to be inserted in the image taking optical axis whereby upon panning or tilting, the strange feeling to the cameraman caused due to the difference of the conversion magnification of the focal length converting optical system may be suppressed.
Furthermore, for example, if the condition for shifting the image blur correcting optical system to the reference position is made to be that the detection signal of the vibration stays for a predetermined time period beyond the limit value, whereby the panning or tilting may be detected without fail.
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A lens system is provided, which comprising:
a) an image taking optical unit having an optical axis;
b) a correction optical component for tilting the optical axis of the image taking optical unit;
c) a conversion optical component insertable into or retractable from the optical axis of the image taking optical unit;
d) a vibration sensor for detecting a vibration;
e) a magnification detection sensor for detecting a conversion magnification of the optical element when the optical element of the conversion optical component is disposed on the optical axis of the image taking optical unit;
f) a driver for driving the correction optical component to tilt the optical axis of the image taking optical unit; and
g) a controller for controlling the drive of the correction optical component by the driver in accordance with the detection output from the vibration sensor, characterized in that:
when the detection output from the vibration sensor exceeds a predetermined limit value, the controller controls the drive of the driver so that the correction optical component is located in the vicinity of the optical axis; and
the controller changes the limit value in correspondence with the output from the magnification detection sensor.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] None
STATEMENT OF GOVERNMENT SPONSORSHIP
[0002] None
BACKGROUND OF THE INVENTION
[0003] I. Field of the Invention
[0004] This invention relates generally to roof or ladder racks mountable on the roof of motor vehicles for transporting one or more extension ladders and/or step ladders to a work site, and more particularly to the ergonomic construction that alleviates the need for a worker to lift the ladder vertically when removing a ladder from the roof rack upon reaching a work site.
[0005] II. Discussion of the Prior Art
[0006] Work vehicles, such as commercial vans, often incorporate a roof rack adapted to support cargo of one type or another to be used at a work site. Such cargo often includes extension ladders and/or step ladders. To avoid loss of the cargo during transport and possible serious injuries to other motorists who may be traveling behind the work vehicle, various means have been devised for securing cargo and especially ladders, to the ladder rack. For example, some have used bungee cords and ropes to tie ladders in place on the vehicle-mounted roof rack, but this is generally a considerable effort, especially given the height and placement of the ladder rack on the van roof. In applicant's printed application US 2011/0214944 A1, which is hereby incorporated by reference herein, there is described a ladder rack and especially an improved clamping structure for releasably securing ladders to a roof mounted ladder rack. It comprises a pair of side rails 12 and 14 that are held in parallel spaced-apart relation by front and rear cross-bars 16 and 18 . In that design, the side rails 12 and 14 are mounted so as to be upwardly offset from the top surface of the cross-bars 16 and 18 .
[0007] A clamp member 60 is affixed to a shaft 42 that is journaled for rotation about an axis parallel to the rear cross-bar 18 . The clamp member in the form of an L-shaped hook can be raised and lowered by manipulating a crank 82 . When the clamp member 60 is in its raised position, such as shown in FIG. 1 of the aforereferenced published application, it is made to engage a ladder rung capturing the ladder between a fixed, front clamp member 22 and the rotatable clamp member 60 . Because the side rails 12 and 14 are elevated with respect to the ladder-supporting cross-bars 16 and 18 , a worker, standing on the ground, must reach up and lift the foot portion of the ladder over the adjacent side rail which has proven to be an arduous task for some workers, especially persons of smaller stature. The present invention obviates this problem by requiring less effort in order to transfer a ladder from its transport position atop the cross bars of the roof rack on the vehicle to a removed position. In the removed position the foot of the ladder is brought down to rest on the ground while the upper portion of the ladder remains in contact with the side rail 12 or 14 and its horn 37 or 39 .
[0008] While, after-the-fact, the present invention may appear simple, it solves a practical problem of allowing a worker to more readily remove or replace ladders from and onto a van mounted roof rack without strain.
SUMMARY OF THE INVENTION
[0009] In accordance with the present invention there is provided a pair of side rails that are held in parallel, spaced-apart relation by front and rear cross-bars. In the present invention, however, rather than having the side rails at a higher elevation than the front and rear cross-bars, the top surface of the cross-bars are made even or flush with the top surface of the side rails so that a ladder can readily be slid off the roof rack without a need to elevate the ladder to clear the side rail.
[0010] To prevent lateral shifting of a ladder during transport, there is added to the shaft of the rotatable clamping member an abutment finger that also rotates with the clamping members shaft so as to block lateral movement of a ladder when the clamping member is engaging a ladder rung but which moves to a non-obstructing position when the ladder clamping member is moved to its release position.
DESCRIPTION OF THE DRAWINGS
[0011] The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of a preferred embodiment, especially when considered in conjunction of the accompanying drawings in which like numerals in the several views refer to corresponding parts.
[0012] FIG. 1 is a partial perspective view of the preferred embodiment of the present invention;
[0013] FIG. 2 is a detailed, close-up view showing the rotatable clamping structure and the junction between the rear cross-bar and a rear-end of a side rail when the clamping member is in its non-rung engaging position;
[0014] FIG. 3 is a view like that of FIG. 1 but with the ladder rung engaging clamp member in its elevated position; and
[0015] FIG. 4 is a view like that of FIG. 2 but with the clamping member in its elevated, rung-engaging disposition.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] This description of the preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “up”, “down”, “top” and “bottom” as well as derivatives thereof (e.g., “horizontally”, “downwardly”, “upwardly”, etc.) should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms such as “connected”, “connecting”, “attached”, “attaching”, “join” and “joining” are used interchangeably and refer to one structure or surface being secured to another structure or surface or integrally fabricated in one piece, unless expressively described otherwise.
[0017] Referring first to FIG. 1 , a vehicle roof rack constructed in accordance with the present invention is indicated generally by numeral 10 . It is seen to comprise at least one, and preferably two, tubular side rails, as at 12 and 14 , of extruded aluminum that are held in parallel, spaced-apart relationship to one another by a front cross-bar 16 and a rear cross-bar 18 . Brackets, as at 20 and 22 , are attached to T-shaped clamping ridges (not shown) formed on the undersurface of the side rails 12 and 14 . The cross-bars 16 and 18 connect to the brackets 20 and 22 such that the top-surface 24 of the cross-bar 18 is even or flush with the arcuate top surface of the side rails 12 and 14 .
[0018] As in applicant's earlier invention of the afore-referenced published application 2011/0214944 A1, affixed to the rear cross-bar 18 is a rear rising clamp assembly indicated generally by numeral 26 . First and second bearing brackets 28 and 30 are used to journal a cylindrical rod 32 for rotation. The bearing brackets 28 and 30 are shown clamped to the rear cross-bar 18 such that the shaft 32 is rotatable about an axis that extends parallel to the rear cross bar 18 .
[0019] Affixed to the shaft 32 is a clamp member in the form of an L-shaped hook 34 that is adapted to engage a rung of a ladder when rotated to a generally vertical position as shown in FIGS. 3 and 4 . When the clamp 34 is in its lower disposition as shown in FIGS. 1 and 2 , it does not engage a ladder rung, allowing the foot of the ladder to be shifted laterally along the top surface 24 of the rear cross-bar and to pass over the junction between the rear cross-bar member 18 and the side rail 12 without the need to lift the ladder as was the case with the embodiment described in the afore-referenced published application 2011/0214944.
[0020] To prevent lateral shifting of a ladder during transport when the rotatable clamp 26 has the hook 34 in its raised disposition, there is provided an abutment finger 36 that is affixed to the shaft 32 by a ring 38 that is riveted or otherwise affixed to the shaft 32 . As can be seen in FIGS. 3 and 4 , when the hook 34 is in its raised disposition so as to engage the rung of a ladder, the abutment finger 36 is also elevated so as to engage a ladders side rail to prevent lateral shifting of the ladder. However, when the clamping assembly is in its lowered disposition, out of engagement with a ladder rung, the abutment finger 36 is recessed with respect to the upper surfaces of the side rail 12 and the cross-bar 18 thereby allowing a worker to slide the ladder's foot portion from the rear cross-bar 18 without needing to lift it.
[0021] As in applicant's earlier invention of the '494 application, a crank arm 40 is provided to facilitate rotation of the shaft 32 . It has been found convenient to install a generally flat shield plate 42 that extends over the rear-end of the side rail 12 so as to be in covering relation with respect to the joint or connection between the handle 40 and its coupling to the end of the shaft 32 . A spring latch 44 is affixed to the side rail 12 to capture the crank arm 40 when the rung clamping hook 34 is in its elevated disposition, such as when ladders on the roof rack are being transported to a work location.
[0022] When a worker arrives at a work site and wishes to remove an extension ladder from the vehicle's roof rack, he or she will depress the trigger on the spring latch 44 to open its jaws and release the crank arm 40 , By rotating the crank arm counterclockwise as viewed in FIG. 1 , the clamp hook 34 will be moved from its vertical disposition, such as in FIG. 4 , to the more horizontal disposition shown in FIG. 1 . At the same time, the abutment finger 36 also rotates to a lowered disposition so that it does not interfere with the ability to slide the foot of the ladder so that its previously innermost ladder side rail no longer rests on the rear cross-bar's top surface 24 . The worker then lowers the ladder's foot onto the ground, keeping the upper portion of the ladder still engaged by the horn affixed to the front end of the side rail 12 . When the ladder is so positioned, the worker can readily move to the ladder's balance point and lift the upper end of the ladder free of the curved horn and walk with the ladder to its point of use. In that the upper surface 24 of the rear cross-bar 18 is flush with the upper surface of the side rail 12 , the worker is not required to lift or elevate the ladder, but only need slide the ladder off from the rear cross-bar's top surface 24 .
[0023] This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment and operating procedures, can be accomplished without departing from the scope of the invention itself.
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An ergonomically improved vehicle ladder rack has the top of its side rail(s) flush with the top surface of the rear cross-bar so that a foot portion of a ladder being transported may be made to slide off from the rack without a need for lifting it. To prevent lateral shifting of the ladder during transport on the vehicle, an abutment finger is added to the rotatable rung clamping assembly. The abutment finger blocks lateral shifting of a ladder when the rung hook is engaging a ladder rung and is non-blocking when the rung is disengaged.
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RELATED APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 07/876,190, filed Apr. 30, 1992, now abandoned, which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to an improved process for solubilizing lyophilized antihemophilic factor (Factor VIII complex) preparations.
BACKGROUND OF THE INVENTION
Coagulation of blood is a complex process requiring the sequential interaction of a large number of components, nearly all of which are proteins. These components include fibrinogen and Factors II, V, VII, VIII, IX, X, XI, and XII. A lack of any of these components, or a nonfunctional component, can lead to an inability of the blood to clot when required, with resultant excessive and life-threatening blood loss to the patient.
Factor VIII (antihemophilic factor) is present at deficient levels, or is absent, in certain individuals. For example, persons who have a deficiency (or absence) of Factor VIII, i.e., persons suffering from hemophilia A, have blood which either fails to clot or clots only after longer periods of time than the time required for clotting in a person who has a normal level of Factor VIII.
Factor VIII is present in plasma as a high-molecular-weight complex (Factor VIII complex), which includes Factor VIII:C and von Willebrand factor (Factor VIII:R or vWf). Factor VIII:C promotes blood coagulation. Factor VIII:R promotes aggregation of platelets and, when incorporated into the Factor VIII complex, acts as a stabilizer for Factor VIII:C.
Purification of the Factor VIII complex has resulted in Factor VIII preparations which have a purity level of about 90% or greater, and which are sufficiently stable for storage for long periods of time in a lyophilized form. As used herein, purity means the amount of the specified protein as a percentage of the total amount of protein in a sample. However, highly-purified, lyophilized Factor VIII complex compositions, i.e., compositions with a high Factor VIII:C specific-activity, are difficult to reconstitute in aqueous solutions such as those required for use in intravenous injection. The purified solutions require contact with solvents for extended periods of time (about 5-6 min.) before they are resolubilized, and often result in reconstituted solutions which have poor clarity, thus wasting valuable time of hospital employees.
In addition, the reconstituted Factor VIII complex compositions have a limited life, requiring that the reconstituted compositions be discarded after a short period of time. This presents difficulties in the treatment of patients who require injections of Factor VIII complex to maintain blood-clotting ability. Typically, such patients are injected with a dose of about 50 units of Factor VIII:C/kg of body weight about every one to two weeks, although injection schedules vary from person to person depending on the severity of the individual's hemophilia.
In U.S. Pat. No. 4,650,858 to Rasmussen et al., Factor VIII is purified using a two-step PEG precipitation purification scheme, wherein an amino acid or other "salting-in" agent is added to the second PEG precipitation to salt-in contaminants and to give a "sharper" purification of the Factor VIII. The salting-in agent used in this method would be substantially removed from the final Factor VIII preparation as a result of the subsequent precipitation of the Factor VIII by PEG. The specific-activity of the Factor VIII is limited to only 3.85 to 50 units/mg.
There is a need to provide a lyophilized Factor VIII complex composition which has enhanced solubility in aqueous solutions. It is also desirable that the reconstituted Factor VIII complex is stable at room temperature, so that, once a solution is reconstituted, it can be stored for extended periods of time prior to use.
SUMMARY OF THE INVENTION
A process for producing a lyophilized Factor VIII complex composition which, when reconstituted, exhibits enhanced solubility, is described. An aqueous solution comprising a Factor VIII complex preparation incorporating at least 50 units of Factor VIII:C activity per milligram of total protein in the preparation is mixed with a solubilizing agent, comprising arginine, to thereby form a Factor VIII/arginine solution. The Factor VIII/arginine solution is lyophilized to thereby provide a lyophilized Factor VIII composition with enhanced solubility.
Histidine and human serum albumin may also be added to the solubilizing agent. In a preferred embodiment arginine is present at a concentration of about 0.05M to about 0.5M, and most preferably from about 0.1 to about 0.2M, prior to lyophilization. Histidine, when added, is present at a concentration of about 0.025M and the human serum albumin, when added, is present at a concentration of about 0.05% to about 3%, preferably about 0.5%, prior to lyophilization.
In a preferred embodiment, the Factor VIII complex preparation has a specific-activity of about 50 to about 500 units/mg, and the lyophilized Factor VIII complex composition is reconstituted with water at room temperature.
DETAILED DESCRIPTION
The process of the present invention provides a simple and efficient method for the preparation of solutions of high specific-activity Factor VIII complex at high concentrations from lyophilized Factor VIII complex compositions. Concentrations of greater than from about 50 units of Factor VIII:C activity/ml are contemplated by the present invention. The phrase "high specific-activity" as used herein means a Factor VIII complex preparation having greater than about 50 units of Factor VIII:C activity/mg of protein. While the reconstitution method of the present invention is suitable for use with high concentrations and high specific-activity Factor VIII complex preparations, it is also suitable for use with lower concentrations and lower specific-activity Factor VIII complex preparations.
The starting material from which the high specific-activity Factor VIII complex product provided in accordance with the present invention is derived, may be cryoprecipitate or other blood plasma-derived fractions, or it may be derived by recombinant-DNA or transgenic techniques.
Any purification procedure which results in a Factor VIII complex having a high Factor VIII:C specific-activity is suitable for use in accordance with the practice of the present invention. In one exemplary embodiment, Factor VIII complex is purified from cryoprecipitate using affinity chromatography and precipitation techniques.
A key step of the process of the present invention is that the high specific-activity Factor VIII complex, from whatever source, is lyophilized in the presence of a sufficient amount of arginine to enhance its solubility. As used herein enhanced solubility means the solubility of the Factor VIII complex which has been lyophilized in the presence of the solubilizing agent of the present invention compared to Factor VIII complex which has been lyophilized in the absence of the solubilizing agent of the present invention. Other amino acids and/or proteins may be present in addition to arginine. Preferably, the high specific-activity Factor VIII complex is lyophilized in an aqueous solution which includes a solubilizing agent, arginine. The solubilizing agent may further comprise histidine and human serum albumin. The Factor VIII complex with enhanced solubility is prepared from an aqueous solution comprising from about 0.05M to about 0.5M arginine and about 0.1 mg to about 5 mg/ml of Factor VIII complex. When added, histidine and human serum albumin are present at a concentration of about 0.025M and about 0.05% (wt/vol) to about 3% (wt/vol), respectively. As used herein % refers to % weight per volume (wt/vol), unless otherwise specified. Preferably, the aqueous solution from which the Factor VIII is lyophilized comprises about 0.1 to about 0.2M arginine, about 0.025M histidine and about 0.5% (wt/vol) human serum albumin. The histidine acts as a buffer. While other buffers may be used, histidine is preferred, since it does not lead to precipitation of the Factor VIII complex or otherwise adversely affect its solubility.
It was discovered that, surprisingly, the arginine acts as a solubilizing agent and aids in the rapid reconstitution of the lyophilized Factor VIII complex. The human serum albumin acts as a bulking agent and aids in the long-term stability of the lyophilized Factor VIII complex, once it has been reconstituted.
Preferably, the Factor VIII complex/solubilization agent solution is aliquoted into separate vials, each of which is filled with an amount of Factor VIII complex sufficient for at least a single dose of Factor VIII complex. The Factor VIII complex composition is then lyophilized to provide a lyophilized Factor VIII composition of enhanced solubility. The lyophilized composition may be stored at about 4° C. until required for use.
When required for use, the lyophilized Factor VIII complex composition, incorporating the solubilization agent, may be readily reconstituted in water or other suitable media. The lyophilized Factor VIII complex reconstitutes in water, in less than 1 min., to provide a solution which has a high degree of clarity and which is stable for extended periods of time at room temperature.
Preparation of Factor VIII Complex for Facilitated Reconstitution
To facilitate the resolubilization of the lyophilized Factor VIII complex, an aqueous solution comprising about 0.1 to about 5 mg/ml of a high specific activity Factor VIII complex preparation, i.e. a Factor VIII complex having an activity of greater than 50 units/mg of Factor VIII:C activity/mg of protein, and arginine is prepared. Histidine and human serum albumin may also be added to the solution. Preferably, the final concentration of the solubilization agent components is about 0.05M to about 0.5M arginine, about 0.025M histidine, and from about 0.05% (wt/vol) to about 3% (wt/vol) human serum albumin. Most preferably, the final concentration of the solubilization agent components is about 0.1M to about 0.2M arginine, about 0.025M histidine, and about 0.5% (wt/vol) human serum albumin. The solution is then lyophilized and stored at 4° C. until required for use. When required for use, the lyophilized Factor VIII complex is dissolved in distilled water or a suitable buffer solution.
The present invention could be practiced with any Factor VIII complex purification procedure which results in the preparation of Factor VIII complex of a high specific-activity.
EXAMPLE 1
Preparation of Purified Factor VIII Complex
9,030 kg of plasma were cryoprecipitated by freezing the plasma at a temperature of about -20° C. and is subsequently thawed at 0° C. to 5° C. The 107 kg of cryoprecipitate which forms during the thawing process was collected and dissolved in 320 liters (1) of distilled water containing about 120 units of heparin per ml of water. The heparin solution was mixed at a temperature of 30° C. until the cryoprecipitate was completely dissolved (approximately 10 min.), to provide a cryoprecipitate/heparin solution. After the cryoprecipitate was dissolved, the pH of the cryoprecipitate/heparin solution was adjusted to about 7, using 0.1M HCl, and the solution was stirred for an additional 20 to 30 min.
An aqueous PEG solution comprising 31.5% (wt/vol) PEG, 0.22% (wt/vol) sodium citrate dihydrate, and 0.08% (wt/vol) citric acid monohydrate, at a pH of 6.2, was then added to the cryoprecipitate/heparin solution, to give a final concentration of 3.5% (wt/vol) PEG. The pH of the PEG/cryoprecipitate/heparin solution was adjusted to 6.3 with dilute acetic acid. The pH-adjusted solution was mixed for approximately 15 min., at a temperature of 27° C. The addition of PEG resulted in precipitation of various contaminating proteins from the Factor VIII complex, which remained in solution.
The PEG precipitate was separated from the Factor VIII complex-containing supernatant solution by centrifugation. The PEG supernatant, i.e., the Factor VIII complex containing impure protein fraction, was recovered. The supernatant was then treated to inactivate viruses which may be present in the blood products, by the addition of a solution containing 0.3% (wt/vol) tri-n-butylphosphate and 1% (wt/vol) TWEEN-80 and incubating at 25° C. for 6 hrs.
The viral-inactivated supernatant solution, i.e., the viral-inactivated Factor VIII complex containing impure protein fraction, was clarified by filtration and then recovered for further purification of Factor VIII complex by affinity chromatography on a heparin-coupled chromatographic medium.
The Factor VIII complex-containing solution was applied to a 200 liter (1) heparin-coupled chromatographic medium packed into the column. The column effluent was collected, and the column was washed with 1700 l of 0.025M histidine, pH 6.8, containing 0.10M NaCl. Elution of Factor VIII complex was achieved with 600 l of 0.1M CaCl 2 and 0.025M histidine, pH 6.8.
The eluate from a heparin column (the column eluate) was concentrated 15-fold using a CENTRASETTE, Omega 100K cassette. The concentrated solution, i.e., the eluate concentrate, was then brought to 2M glycine and 1.2M NaCl and mixed at 25° C. for 2 hours. The precipitate which formed was collected by centrifugation and washed with a wash solution comprising 0.025M histidine, pH 6.8, 2M glycine, and 1.3M NaCl. The washed precipitate was collected by filtration.
To perform an assay on the purified Factor VIII complex, a sample of the washed precipitate was dissolved in a buffer comprising 0,025M histidine, 0.1M arginine, pH 7.0 to 7.6, to a concentration of 0.5 mg of Factor VIII complex/ml of buffer.
The resultant solution and aliquots taken from various stages during the purification, were then assayed for Factor VIII:C blood-clotting activity using a COAG-A-MATE XC clotting machine. The results are summarized in Table I.
TABLE I______________________________________ Specific- Units.sup.1 × Units.sup.1 /kg ActivitySample 10.sup.-3 Plasma units/mg______________________________________Plasma 9,030 1,000 0.01Cryoprecipitate 3,540 392 0.7PEG-supernatant 3,645 404 1.5Column eluate 2,640 292 --Eluate Conc. 1,540 171 14.5Glycine/NaCl 782 87 99.1precipitate______________________________________ .sup.1 Units of Factor VIII:C specificactivity.
The resultant purified Factor VIII complex solution was further analyzed to evaluate the contaminating proteins present. The results are summarized in Table II.
TABLE II______________________________________Specific-activity (Factor VIII:C units/mg) 99.1Fibronectin (μg/unit*) 1.5Fibrinogen (μg/unit) <0.8IgG (μg/unit) <0.1IgM (μg/unit) ≦0.1HSA (μg/unit) <0.1______________________________________ *per unit of Factor VIII:C
EXAMPLE 2
Lyophilization and Reconstitution of Purified Factor VIII Complex
Separate samples of a washed precipitate of Factor VIII complex, prepared as described in Example 1, were dissolved in solutions, incorporating a variety of constituents, to provide a concentration of 3 mg of Factor VIII complex/mi. The solutions were then lyophilized and the lyophilized Factor VIII complex was reconstituted with distilled water at room temperature with gentle agitation. The samples were observed, and the time required for the Factor VIII complex to dissolve was noted, as was the general appearance of the reconstituted Factor VIII. The constituents of the solutions used to dissolve the washed Factor VIII complex precipitate are summarized in Table III, and the results are summarized in Table IV.
TABLE III______________________________________SolutionNumber Constituents______________________________________1 0.025 M histidine, 3 mg/ml Factor VIII complex2 0.1 M histidine, 3 mg/ml Factor VIII complex3 0.1 M glycine, 0.025 M histidine, 3 mg/ml Factor VIII complex4 0.28 M glycine, 0.025 M histidine, 3 mg/ml Factor VIII complex5 0.28 M glycine, 0.025 M histidine, 3% (wt/vol) dextrose, 3 mg/ml Factor VIII complex6 0.1 M lysine, 0.025 M histidine, 3 mg/ml Factor VIII complex7 0.28 M alanine, 0.025 M histidine, 3 mg/ml Factor VIII complex8 0.1 M arginine, 0.025 M histidine, 3 mg/ml Factor VIII complex9 0.1 M arginine, 0.025 M histidine, 0.5% (wt/vol) human serum albumin, 3 mg/ml Factor VIII complex10 0.28 M arginine, 0.025 M histidine, 3 mg/ml Factor VIII complex11 0.28 M arginine, 0.025 M histidine, 0.5% (wt/vol) human serum albumin, 3 mg/ml Factor VIII complex______________________________________
TABLE IV______________________________________ Constituents Reconsti- in Factor VIII tutionNo. Solution Time (sec.) Appearance______________________________________1 0.025 M histidine 170 tiny protein strings2 0.1 M histidine 240 hazy3 0.1 M glycine, 480 hazy 0.025 M histidine4 0.28 M glycine, 720 not clear 0.025 M histidine5 0.28 M glycine, 110 not clear 0.025 M histidine, 3% (wt/vol) dextrose6 0.1 M lysine, 360 not clear 0.025 M histidine7 0.28 M alanine, 480 hazy 0.025 M histidine8 0.1 M arginine, 50 clear 0.025 M histidine9 0.1 M arginine, 15 clear 0.025 M histidine, 0.5% (wt/vol) human serum albumin10 0.28 M arginine, 50 clear 0.025 M histidine11 0.28 M arginine, 40 clear 0.025 M histidine, 0.5% (wt/vol) human serum albumin______________________________________
The results indicate that arginine is effective as an agent to enhance the resolubilization of lyophilized Factor VIII complex as can be seen from a comparison of the results in Examples 3, 4 and 7 with Example 8. In these Examples an amino acid is combined with a buffer, histidine. Only the combinations which incorporated arginine were found to be effective as reconstitution agents. Histidine alone, see Examples 1 and 2, was not and 2, was not an effective reconstitution agent. The combinations 0.1M arginine, 0,025M histidine; 0.1M arginine, 0.025M histidine, 0.5% (wt/vol) human serum albumin; 0.28M arginine, 0,025M histidine; and 0.28M arginine, 0.025M histidine, and 0.5% (wt/vol) human serum albumin are effective as agents to enhance the resolubilization of lyophilized Factor VIII complex.
EXAMPLE 3
Stability of Reconstituted Purified Factor VIII Complex
A washed precipitate of Factor VIII complex, prepared as described in Example 1, was dissolved to a concentration of 3 mg of Factor VIII complex in 0.025M histidine. The sample was divided into two portions. One portion was brought to 0.1M arginine and 0.5% (wt/vol) human serum albumin by the addition of arginine and human serum albumin. The other portion was brought to 0.1M glycine and 0.5% (wt/vol) human serum albumin by the addition of glycine and human serum albumin. The samples were then lyophilized. Each of the lyophilized preparations was then reconstituted in water, to give a Factor VIII complex concentration of 3 mg/ml, and the samples were incubated at room temperature for up to 22 days. Each of the reconstituted Factor VIII complex solutions was sampled periodically and assayed for Factor VIII:C activity. The results are summarized in Table V.
TABLE V______________________________________% Specific-Activity Remaining When Incubated In: 0.1 M Arg, 0.025 M 0.1 M Gly, 0.025 MDay His, 0.5% HSA His, 0.5% HSA______________________________________0 100 1003 119 929 123 7322 88 2______________________________________ Arg = Arginine His = Histidine Gly = Glycine HSA = Human Serum Albumin
The results indicate that a preparation containing 0.1M arginine, 0.025M histidine, and 0.5% (wt/vol) human serum albumin is effective in stabilizing Factor VIII complex when it is reconstituted in an aqueous solution and that 88% of the original, reconstituted activity of the Factor VIII complex was retained after 22 days at room temperature. Only 2% of the original, reconstituted activity of the Factor VIII complex was retained in samples that had glycine in place of arginine.
The above descriptions of exemplary embodiments of processes for facilitating the reconstitution of lyophilized Factor VIII complex compositions are for illustrative purposes. Because of variations which will be apparent to those skilled in the art, the present invention is not intended to be limited to the particular embodiments described above. The present invention may also be practiced in the absence of any element not specifically disclosed. The scope of the invention is defined by the following claims.
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A process for facilitating the reconstitution of lyophilized Factor VIII complex compositions, and compositions of Factor VIII complex, which are readily reconstituted. The process of the present invention comprises providing a purified Factor VIII complex preparations; adding a stabilization agent comprising arginine; lyophilizing the stabilization agent-Factor VIII complex solutions; and reconstituting the lyophilized stabilization agent-Factor VIII complex by contacting it with solvent for less than one minute.
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This application is a continuation of application Ser. No. 537,278, filed 9/29/83, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a process for recovering a finished oil product from contaminated or crude waste oils, and apparatus for carrying out the process. In particular, the present process calls for introducing vapors which are produced from heating of the waste oil in a tank by a gas or oil fired flame, back into the flame so that light ends included in the vapors are combusted by the flame to provide additional heat for heating the waste oil in the tank. The present apparatus includes burner means for heating the waste oil in the tank, together with suitable afterburner means for combusting the vapors with the flame provided by the burner means.
It is known to recycle vapors produced when crude oil is heated by a furnace, back through a heat exchanger wherein the heat of the vapors is transferred to an incoming crude oil stream for purposes of preheating the stream. Such an arrangement is disclosed in U.S. Pat. No. 4,321,132 issued Mar. 23, 1982. In the system of the '132 patent, however, a main furnace-heater is provided for elevating the temperature of the crude oil stream to about 600° F., and a separate flash separator is provided for dividing the heated stream into a vapor portion is routed through a separate heat exchanger to preheat the incoming crude oil stream. From the heat exchanger, the vapor portion is then conducted to a fractionation column. U.S. Pat. No. 4,292,140, issued Sept. 29, 1981, relates to a distillation process in which heats of distillates and bottom products are recovered by heat exchangers so as to preheat a main feed, and the heat of the distillates is transferred to boiler water to generate steam. According to the patent, the steam can be used to atomize fuel which fires a heating furnace, and may also be injected into the main feed line in the heating furnace to increase the flow of feed charged into the distillation column.
The known conventional waste oil recovery processes fail, however, to utilize efficiently all the heat which may be obtained from the vapors produced upon heating of the waste oil, for preheating or supplemental heating of the waste oil in a recovery system.
SUMMARY OF THE INVENTION
An object of the present invention is to overcome the above and other shortcomings in the known prior waste oil recovery or purifying processes and systems.
Another object of the invention is to provide for the combustion of vapors produced during heating of waste oil to be recovered, to provide an additional measure of heat to the waste oil.
Another object of the invention is to provide for the combustion of vapors produced during heat of waste oil to be recovered, wherein the vapors are introduced into a flame provided by a burner which serves as a primary heating source for the waste oil.
Another object of the invention is to provide for the combustion of vapors produced upon heating of waste oil to be recovered, by introducing the vapors into a flame provided by a burner within a waste oil preheat tank, so as to provide an additional measure of preheating of the waste oil before the waste oil is further heated and recovered in a separate still tank.
According to the invention, a process for recovering a finished oil product from waste oil includes containing the waste oil in a tank, heating the waste oil with a heating flame until a desired finished product is produced in the tank together with vapors including light ends, introducing the vapors into the heating flame to provide additional heat to the waste oil, and discharging the finished product from the tank.
Apparatus according to the invention includes a tank for containing waste oil, burner means for heating the waste oil so that vapors and a desired finished product are produced from the waste oil, the burner means producing a flame which is fueled by an outside supply, afterburner means associated with the burner means for combusting the vapors produced in the tank to provide additional heat to the waste oil, and outlet means for discharging the finished product from the tank.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawing and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a schematic representation of a waste oil purifying process and apparatus according to the present invention;
FIG. 2 is a sectional view through a preheat tank in FIG. 1, showing an arrangement for combusting waste oil vapors within a burner incineration chamber;
FIG. 3 is a sectional view through a still tank in FIG. 1, including a discharge pipe arrangement;
FIG. 4 is a perspective view of the waste oil preheat tank arranged as a mobile unit;
FIG. 4A is a simplified sectional view along line A--A in FIG. 4; and
FIG. 5 is a perspective view of the still tank arranged as a mobile unit.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows apparatus constructed and arranged to recover crude and waste oils which are contaminated with water and the like. Basically, a pre-heat tank 10 is provided for receiving the incoming crude or waste oil. The pre-heat tank 10 itself can be trailer mounted as shown in FIG. 4, and may typically comprise a 30,000 gallon, 101/2 foot diameter tank with an associated burner 12 a part of which extends out from the lower rear end wall of the tank 10.
After cold crude or waste oil is filled into the tank 10 through a top opening 14, the cold waste oil is conducted through a suction line 16 which extends length-wise along the bottom of the tank 10 to a circulation pump 18 as shown in FIG. 4. The pump 18 then forces the waste oil through a perforated spray bar or pipe 20 which also extends along the bottom of the tank 10 generally parallel to the suction pipe 16. The spray pipe 20 thus helps to circulate sediment and keep it in suspension so as to prevent the buildup of sediment at the bottom of the pre-heat tank 10. A shaker screen arrangement 22 at the top of the front end of the pre-heat tank 10 also may be provided as shown in FIG. 4, wherein a shaker screen 24 serves to separate solids from the liquid waste oil. A separator discharge pipe 26 conducts the screened waste oil back into the pre-heat 10. The shaker screen arrangement 22 is mounted on a frame 28 exterior of the pre-heat tank 10 at the front end wall of the tank 10 as shown in FIG. 4.
The pre-heat tank burner 12 can be, for example, a model 400 gas/oil burner manufactured by Infern-o-Therm Corporation of Keyport, New Jersey, together with a weatherproof burner enclosure attached to the lower portion of the tank rear end wall, as shown in FIG. 4.
Associated with the pre-heat tank burner 12 is a generally cylindrical main incineration chamber 30 located in the lower rear portion of the pre-heat tank 10 and having its axis parallel to that of the tank 10. The incineration chamber 30 has a diameter of about 46 inches and is refractory lined. Combustion of a flame produced by the pre-heat tank burner 12 from an outside gas or oil supply occurs within the incineration chamber 30, together with combustion of waste oil vapors introduced into the incineration chamber 30 (see FIG. 2) as described further below. A pair of blowers 32 are arranged outside the pre-heat tank 10 as shown in FIG. 1, to direct combustion air through four secondary air inlets arranged tangentially relative to the inner circumference of the incineration chamber 30 as depicted in FIG. 2.
A 20 inch diameter primary heat transfer tube 34 extends from the end of the main incineration chamber 30 further from the burner 12, in heat exchange relation with surrounding waste oil contained in the pre-heat 10. Further, as shown in FIG. 4, a number of secondary heat transfer tubes 36, each of about 8 inch diameter, extend from the circumference of the heat transfer tube 34 at the forward end of the tube 34, wherein the secondary heat transfer tubes 36 bend at right angles to run parallel to the axis of the primary heat transfer 34 over a certain distance, and then bend again at right angles into associated stacks 38 which extend vertically through the top of the pre-heat tank 10, as shown in FIG. 4. The stacks 38 preferably are individually jacketed over their vertical lengths within the pre-heat tank 10.
A jacketed stack 40 extends vertically within the pre-heat 10 through a top opening in the circumference of the main incineration chamber 30 and out through the top of the pre-heat tank 10. The stack typically is of 20 inch diameter, refractory lined, and has a 26 inch surrounding jacket 42. The incineration chamber stack 40 preferably has a damper (not shown) mounted at the top of the stack, the damper being electrically controlled by a thermocouple so that when the temperature of the oil in the pre-heat tank 10 exceeds a certain level, e.g. 160° F., the damper will begin to open thus releasing heat from the incineration chamber 30. Such damper action will control the temperature in the pre-heat tank 10. As seen in FIG. 4A, hot exhaust from stack 40 causes fresh cooling air to flow in through pipes 42a, 42b and through annular space 42c to cool stack 40 and jacket 42 to prevent flash fires in the pre-heat tank 10.
A vapor pipeline 44 is arranged to extend partly along the top length of the pre-heat tank 10, as shown in FIG. 4, and to bend at one end to enter the pre-heat tank 10 and branch into separate interior vapor lines 46 in proximity to the outer circumference of the main incineration chamber 30, close to the end of the incineration chamber 30 which faces the burner 12. As shown in detail in FIG. 2, the vapor lines 46 have a total of four injection nozzles 48 each of which extend coaxially within an associated air intake passage 50. The air intake passages 50 communicate with a pair of air inlet ducts 52 each of which leads from a corresponding one of the two external air blowers 32. The four air intake passages 50 together with the injection nozzles 48 are equally circumferentially spaced every 90 degrees on the main incineration chamber 30, and operate to direct a mixture of waste oil vapor from the vapor return pipeline 44 and outside air supplied by the blowers 32 tangentially to the inner circumference of the main incineration chamber 30 in the same circumferential direction. The vapor and air mixture thus swirls against the heated inner refractory surface of the chamber 30. The arrangement of the injection nozzles 48 and air intake passages 50 provides for the afterburning of waste oil vapors supplied through the vapor pipeline 44, such vapors being produced when the waste oil is heated above a certain temperature either in a single tank, or in a separate still tank 60 as represented in FIG. 1 and shown in detail in FIG. 5.
It has been discovered that by providing four injection nozzles 48 within the associated air intake passages 50 in the manner disclosed in FIG. 2, a venturi of steam contained in the returned oil vapor as mixed with air supplied by the blowers 32 significantly influences the even distribution of gas and air within the incineration chamber 30. Light ends contained in the return vapors are combusted by the frame heat developed by the burner 12 in the main incineration chamber 30, and the injected steam and air mixture travels down past the main incineration chamber 30, through the primary heat transfer tube 34, and back through the secondary heat transfer tubes 36 and out of the stacks 38. Accordingly, heat obtained from the after burning of the waste oil vapors returned to the main incineration chamber 30, together with that provided by the burner 12, is transferred to the waste oil contained in the pre-heat tank 10.
The end of the vapor return pipeline 44 remote from the main incineration chamber 30 in the pre-heat tank 10, bends at a right angle transversely of the axis of the pre-heat tank 10 and extends a certain distance away from the tank 10 before assuming an upward right angle bend at 54 to rise a certain distance above the ground, and two further right angle bends at 56 and 58 so that the vapor return pipeline 44 opens downwardly to be coupled to a condensate tower 62 extending above the still tank 60 as shown in FIG. 5.
A waste oil supply pipe 64 also extends out and away from the pre-heat tank 10 for supplying the waste oil which has been heated in the pre-heat tank 10 above a certain temperature (e.g., 160° F.), to the still tank 60. The heated waste oil supply pipe 64 is coupled to the circulation pump 18 mounted at the forward end of the pre-heat tank 10 through a modulating valve 66 as shown in FIG. 4. The modulating valve 66 is controlled by a temperature probe 68 (FIG. 3) in contact with the waste oil delivered to and contained in the still tank 60. The modulating valve thus is controlled to maintain a certain degree of temperature of the oil in the still tank 60 so that a desired percentage of water will be present in the finished oil product. That is, the modulating valve 66 controls the supply of oil from the pre-heat tank 10 to the still tank 60 to maintain a predetermined temperature of the oil in the still tank 60 such as, for example, 250° F.
As shown in FIG. 5, and represented in FIG. 1, the still tank 60 comprises an elongate cylindrical tank, typically of 8 foot diameter and 10,000 gallon capacity. The still tank 60 can be trailer mounted as shown in FIG. 5 so that, together with the pre-heat tank 10 which also can be trailer mounted as shown in FIG. 4, the entire present waste oil purifying apparatus can be made mobile for use at any desired location.
The lower rear end portion of the still tank 60 is also fitted with a gas/oil burner such as the Infern-o-Therm model 400 provided on the pre-heat tank 10. The still tank burner 69 has an associated two-foot diameter heat transfer tube 70 which extends through the rear end wall of the still tank 60 and inside the tank 60 parallel to the tank axis over a certain length. At the end of the primary heat transfer tube 70 further from the burner 69, a pair of secondary heat transfer tubes 72 extend from the circumference of the tube 70 and bend at right angles to run a certain length back within the tank 60 toward the end of the tank closer to the burner 69. The secondary heat transfer tubes 72 then bend at right angles upward into a pair of jacketed stacks 74 which protrude from the rear top portion of the still tank 60 as shown in FIG. 5.
Heated waste oil pumped through the supply pipe 64 from the pre-heat tank 10 is introduced into the still tank 60 through a waste oil inlet pipe 76 at the forward end of the still tank 60. Inlet pipe 76 is coupled to a spray bar 78 which extends within the upper portion of the still tank 60, parallel to the tank axis (see FIGS. 3 and 5). As shown in FIG. 3, the spray bar 78 has perforations opening upwardly so that heated waste oil pumped into the spray bar 78 is directed through the perforations upwardly against an angle shield 80 (not shown in FIG. 5). The spray bar 78 is located in the still tank 60 so as always to be above liquid contained in the tank 60. Inasmuch as the still tank burner 69 is arranged to maintain an oil temperature in the still tank 60 of about 250° F., the incoming heated waste oil deflected off of the angle shield 80 will hit the hot surface of the oil in the still tank 60, and water vapor and light ends in the heated waste oil thus will be flashed off. The water vapor and light ends flashed off from the surface of the hot waste oil in the still tank 60, then rise through the condensate tower 62 atop the tank 60, to be conducted through the vapor return pipeline 44 of the pre-heat tank 10, the pipeline 44 being connected to the top of the condensate tower 62 when the pre-heat tank 10 and its associated piping is properly positioned relative to the still tank 60 with its appurtenant fixtures.
Preferably, the still tank 60 has its own re-circulating pump (not shown) for pulling off waste oil from the bottom of the tank 60 and re-circulating the pulled off oil into the spray bar pipe 78. Such arrangement also helps to raise the temperature of the oil in the still tank 60 thus aiding flash-off of the light-ends by re-circulating the oil which is heated to about 250° F.
The finished oil product is siphoned off the upper level of the heated oil in the still tank 60 by an outlet arrangement 82. The outlet arrangement 82 includes, within the still tank 60, an interior trap assembly 84 (FIG. 5) through which the oil product flows after it is drawn by an inverted U-tube 86. The siphon loop thus formed is located so that the oil level will rise about 10 inches above the top of the siphon loop, and will be drawn down to the bottom of the U-tube 86. Such arrangement allows for about a 14 inch draw down of finished product on each cycle.
An exterior trap assembly 88 has a drain and sampling valve 90 located at its bottom-most portion outside the still tank 60. The exterior trap assembly 88 leads into a finished product supply pipe 92 which is routed partway along the exterior length of the still tank 60 and then bent away from the tank 60 to an outlet nozzle 94 (FIG. 5) which may direct the finished product into a holding tank 96 as represented in FIG. 3.
The interior trap assembly 84 serves to prevent steam vapors from leaving the still tank 60 with the finished product.
As disclosed above, the present waste oil purifying apparatus is constructed and arranged to recover waste or crude oils contaminated with water and the like, wherein an after burner arrangement provided in a pre-heat tank burner combusts light end oils and incinerates steam vapor and odors at a temperature of approximately 1800° F., or more.
The pre-heat tank 10 receives incoming crude or waste oil, and the pre-heat tank burner 12 together with the afterburner arrangement in the main incineration chamber 30 of the burner 12, raises the temperature of the waste oil in the pre-heat tank 10. The heated waste oil is then pumped through the modulating valve 66 associated with the pre-heat tank 10, to the still tank 60. The temperature probe 68 in the still tank 60 controls the modulating valve 66 to maintain a desired temperature of the oil in the still tank of about 250° F., and thus to maintain a desired percentage of water in the finished product.
Heated waste oil entering the still tank 60 is directed through perforations in the spray bar 78 against the angle shield 80, to strike the surface of the hot oil in the still tank. The flashed off water vapor and light ends exit through the condensate tower 62 atop the still tank, and pass to the afterburner arrangement in the main incineration chamber 30 of the pre-heat tank, for combustion.
Once the still tank is brought up to the desired temperature, the flow rate of finished product obtainable, depending upon the percentage of water, may vary from between 1000 to 3000 gallons or more per hour.
Various modifications of the present apparatus and process will of course be apparent to those skilled in the art. For example, a second afterburner arrangement could be installed in the still tank 60 to operate together with the afterburner arrangement in the pre-heat tank 10, for combusting the waste oil vapors produced in the still tank. The temperature in the pre-heat tank then may be maintained at 215° to 220° F. The temperature in the still tank would be set to approximately 250° F. to obtain about one-half of 1% of water. The higher the still tank temperature, the drier the finished product.
On smaller installations, where no pre-heat tank is necessary, the present afterburner arrangement then would be provided directly in the still tank, and a relief stack with a damper would be used to control the heat rise in the still tank, and also be used on shut-down. The still tank then would have a pipe coil where cold oil from a storage tank would be pumped through to reduce the temperature of the still tank at shut-down.
The product supplied to the system generally has about 10% water content. Conventionally, this water would be distilled out. Disposal of the distilled-out water is very expensive. With the present invention, the water is effectively disposed of by "incineration" of the steam produced therefrom so that the resulting water content in the purified product is only about one-half of 18%. This is an industry-acceptable percentage of water in the resulting finished oil product.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the invention principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A finished oil product is recovered from crude or waste oil contaminated with water and the like by heating the waste oil in a tank with a heating flame which may be gas or oil fired. The waste oil is heated until vapors including light ends and the desired finished oil product are produced from the waste oil within the tank. The vapors are introduced into the heating flame so that additional heat is developed by such afterburning to heat the waste oil in the tank. The finished oil product as recovered from the waste oil is discharged from the tank by a suitable outlet pipe arrangement.
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RELATED DOCUMENTS
The present application is a continuation of U.S. Ser. No. 09/770,997, filed Jan. 25, 2001, which claims the benefit of provisional patent application Ser. No. 60/178,910, filed Jan. 26, 2000, by Xinhui Niu and Nickhil Harshavardhan Jakatdar, entitled Cached Coupled Wave Method for Diffraction Grating Profiled Analysis, all of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
The present invention relates generally to the measurement of complete profiles of one-dimensionally and two-dimensionally repeating, regularly-spaced series of structures through the use of an algorithm for caching of intermediate results, and the use of cached intermediate results to increase the efficiency of calculations. The present invention also relates to coupled wave analyses of diffracted electromagnetic signals from periodic gratings, particularly where the diffracted electromagnetic signals are monitored by optical metrology tools, such as reflectometer and ellipsometers. More particularly, the present invention relates to apparatus and methods for measurement of complete profiles of one-dimensionally and two-dimensionally repeating, regularly-spaced series of structures and to reducing the computation time of coupled wave analyses of diffraction from periodic gratings, and still more particularly the present invention relates to apparatus and methods for caching and retrieval of intermediate computations to reduce the computation time of coupled wave analyses of diffraction from periodic gratings.
Diffraction gratings have been used in spectroscopic applications, i.e., diffraction applications utilizing multiple wavelengths, such as optical instruments, space optics, synchrotron radiation, in the wavelength range from visible to x-rays. Furthermore, the past decades have seen the use of diffraction gratings in a wide variety of nonspectroscopic applications, such as wavelength selectors for tunable lasers, beam-sampling elements, and dispersive instruments for multiplexers.
Advances in computing power are the result of increased speed of semiconductor devices. This has been achieved by continually reducing the transistor linewidths, i.e., the dimensions of transistors. However, as the scale of semiconductor devices decreases, control of the complete profile of the features, rather than the linewidth alone, is crucial for effective chip operation. When the sidewalls are perfectly vertical, knowledge of linewidth (and height) is enough to reconstruct the entire line, i.e., two parameters define the structure. However, due to limits in current fabrication technologies, vertical sidewalls are difficult, if not impossible, to achieve, and sloping sidewalls are common. In addition to the slope of a sidewall, other features that are artifacts of the technology which may be present in lines include T-topping (the formation of a “T” shaped profile) and footing (the formation of an inverse “T” shaped profile). Capturing such details about the profile is important in achieving a better understanding the fabrication technologies. In addition to measuring such features, controlling them is also important in this highly competitive marketplace. There are thus increasing efforts to develop and refine run-to-run and real-time fabrication control schemes that attempt to make profile measurements in-line or in-situ, and use this information to reduce process variability.
The use of reflectance metrology for the measurement of the thickness of films is well-known. In reflectance metrology, an unpolarized or polarized beam of broadband light is directed towards a sample, and the reflected light is collected. The reflectance can either be measured as absolute value, or relative value when normalized to some reflectance standards. The reflectance signal is then analyzed to determine the thicknesses and optical constants of the film or films. There are numerous examples of reflectance metrology. For example, U.S. Pat. No. 5,835,225 given to Thakur et. al. teaches the use of reflectance metrology to monitor the thickness and refractive indices of a film.
The use of ellipsometry for the measurement of the thickness of films is also well-known (see, for instance, R. M. A. Azzam and N. M. Bashara, “Ellipsometry and Polarized Light”, North Holland, 1987). When ordinary, i.e., non-polarized, white light is sent through a polarizer, it emerges as linearly polarized light with its electric field vector aligned with an axis of the polarizer. Linearly polarized light can be defined by two vectors, i.e., the vectors parallel and perpendicular to the plane of incidence. Ellipsometry is based on the change in polarization that occurs when a beam of polarized light is reflected from a medium. The change in polarization consists of two parts: a phase change and an amplitude change. The change in polarization is different for the portion of the incident radiation with the electric vector oscillating in the plane of incidence, and the portion of the incident radiation with the electric vector oscillating perpendicular to the plane of incidence. Ellipsometry measures the results of these two changes which are conveniently represented by an angle Δ, which is the change in phase of the reflected beam ρ from the incident beam; and an angle Ψ, which is defined as the arctangent of the amplitude ratio of the incident and reflected beam, i.e.,
ρ = r p r s = tan ( Ψ ) ⅇ j ( Δ ) ,
where r p is the p-component of the reflectance, and r s is the s-component of the reflectance. The angle of incidence and reflection are equal, but opposite in sign, to each other and may be chosen for convenience. Since the reflected beam is fixed in position relative to the incident beam, ellipsometry is an attractive technique for in-situ control of processes which take place in a chamber.
There are numerous examples of the use of spectroscopic ellipsometry. For example, U.S. Pat. No. 5,131,752 by Yu et.al. teaches the use of ellipsometry to monitor the thickness of a film as it is deposited on a workpiece. The method is however limited to planar surfaces. U.S. Pat. No. 5,739,909 by Blayo et.al. teaches a method for using spectroscopic ellipsometry to measure linewidths by directing an incident beam 131 of polarized light at a periodic structure 100 , which has a pitch comprising a feature 121 and a space, as is depicted in FIG. 1. A diffracted beam 132 , which leaves the periodic structure at an angle θ which is equal, but opposite in sign, to the angle θ the incident beam makes with the periodic structure, is detected and its intensity and polarization are determined at one or more wavelengths. This is then compared with either pre-computed libraries of signals or to experimental data, to extract linewidth information. While this is a non-destructive test, it does not provide profile information, but yields only a single number to characterize the quality of the process. Another method for characterizing features of a patterned material is disclosed in U.S. Pat. No. 5,607,800 by D. H. Ziger. According to this method, the intensity, but not the phase, of zeroth-order diffraction is monitored for a number of wavelengths, and correlated with features of the patterned material.
While numerous non-destructive techniques have been suggested for linewidth measurements, such as the scanning electron microscope (SEM) and optical microscope, none of them have the ability to provide complete profile information. There exist cross-sectional profile metrology tools, such as the atomic force microscope (AFM) and the transmission electron microscope, that provide profile information, but at the cost of being either prohibitively slow or destructive. Further disadvantages include that these techniques cannot be implemented in-line or in-situ. Finally, there exists scatterometry techniques, such as U.S. Pat. No. 5,867,276 by McNeil et.al. which teaches a method for measuring profile information. This is accomplished by directing multiple wavelength, polarized light onto a periodic structure at a single angle of incidence, and collecting the diffracted intensity signal. It is important to note that the incident beam is of a single planar polarization. This diffracted signal is then compared to a pre-compiled library of signals to extract profiles of features. The library is either pre-computed based on theoretical calculations or is based purely on experimental signals. This method uses only the intensity of the optical signal and has been shown to suffer from non-uniqueness, i.e., there exist scenarios where two completely different profiles yield the same intensity signal, even across a broad range of wavelengths (see, for example, S. Bushman, S. Farrer, “Scatterometry Measurements for Process Monitoring of Gate Etch”, AEC/APC Workshop IX, Sematech, Sep. 20-24, 1997). This non-uniqueness reduces robustness and accuracy of the results.
The ability to determine the diffraction characteristics of periodic gratings with high precision is useful for the refinement of existing applications. Furthermore, the accurate determination of the diffraction characteristics of periodic gratings is useful in extending the applications to which diffraction gratings may be applied. However, it is well known that modeling of the diffraction of electromagnetic radiation from periodic structures is a complex problem that requires sophisticated techniques. Closed analytic solutions are restricted to geometries which are so simple that they are of little interest, and current numerical techniques generally require a prohibitive amount of computation time.
The general problem of the mathematical analysis of electromagnetic diffraction from periodic gratings has been addressed using a variety of different types of analysis, and several rigorous theories have been developed in the past decades. Methods using integral formulations of Maxwell's equations were used to obtain numerical results by A. R. Neureuther and K. Zaki (“Numerical methods for the analysis of scattering from nonplanar periodic structures,” Intn'l URSI Symposium on Electromagnetic Waves , Stresa, Italy, 282-285, 1969) and D. Maystre (“A new general integral theory for dielectric coated gratings,” J. Opt. Soc. Am ., vol. 68, no. 4, 490-495, April 1978). Methods using differential formulations of Maxwell's equations have also been developed by a number of different groups. For instance, an iterative differential formulation has been developed by M. Neviere, P. Vincent, R. Petit and M. Cadilhac (“Systematic study of resonances of holographic thin film couplers,” Optics Communications , vol. 9, no. 1, 48-53, September 1973), and the rigorous coupled-wave analysis method has been developed by M. G. Moharam and T. K. Gaylord (“Rigorous Coupled-Wave Analysis of Planar-Grating Diffraction,” J. Opt. Soc. Am ., vol. 71, 811-818, July 1981). Further work in RCWA formulations has been done by E. B. Grann and D. A. Pommet (“Formulation for Stable and Efficient Implementation of the Rigorous Coupled-Wave Analysis of Binary Gratings,” J. Opt. Soc. Am. A , vol. 12, 1068-1076, May 1995), and E. B. Grann and D. A. Pommet (“Stable Implementation of the Rigorous Coupled-Wave Analysis for Surface-Relief Dielectric Gratings: Enhanced Transmittance Matrix Approach”, J. Opt. Soc. Am. A , vol. 12, 1077-1086, May 1995).
Conceptually, an RCWA computation consists of four steps:
The grating is divided into a number of thin, planar layers, and the section of the ridge within each layer is approximated by a rectangular slab. Within the grating, Fourier expansions of the electric field, magnetic field, and permittivity leads to a system of differential equations for each layer and each harmonic order. Boundary conditions are applied for the electric and magnetic fields at the layer boundaries to provide a system of equations. Solution of the system of equations provides the diffracted reflectivity from the grating for each harmonic order.
The accuracy of the-computation and the time required for the computation depend on the number of layers into which the grating is divided and the number of orders used in the Fourier expansion.
A number of variations of the mathematical formulation of RCWA have been proposed. For instance, variations of RCWA proposed by P. Lalanne and G. M. Morris (“Highly Improved Convergence of the Coupled-Wave Method for TM Polarization,” J. Opt. Soc. Am. A, 779-784, 1996), L. Li and C. Haggans (“Convergence of the coupled-wave method for metallic lamellar diffraction gratings”, J. Opt. Soc. Am. A, 1184-1189, June, 1993), and G. Granet and B. Guizal (“Efficient Implementation of the Coupled-Wave Method for Metallic Lamellar Gratings in TM Polarization”, J. Opt. Soc. Am. A, 1019-1023, May, 1996) differ as whether the Fourier expansions are taken of the permittivity or the reciprocal of the permittivity. (According to the lexography of the present specification, all of these variations are considered to be “RCWA.”) For a specific grating structure, there can be substantial differences in the numerical convergence of the different formulations due to differences in the singularity of the matrices involved in the calculations, particularly for TM-polarized and conically-polarized incident radiation. Therefore, for computational efficiency it is best to select amongst the different formulations.
Frequently, the profiles of a large number of periodic gratings must be determined. For instance, in determining the ridge profile which produced a measured diffraction spectrum in a scatterometry application, thousands or even millions of profiles must be generated, the diffraction spectra of the profiles are calculated, and the calculated diffraction spectra are compared with the measured diffraction spectrum to find the calculated diffraction spectrum which most closely matches the measured diffraction spectrum. Further examples of scatterometry applications which require the analysis of large numbers of periodic gratings include U.S. Pat. Nos. 5,164,790, 5,867,276 and 5,963,329, and “Specular Spectroscopic Scatterometry in DUV lithography,” X. Niu, N. Jakatdar, J. Bao and C. J. Spanos, SPIE, vol. 3677, pp. 159-168, from thousands to millions of diffraction profiles must be analyzed. However, using an accurate method such as RCWA, the computation time can be prohibitively long. Thus, there is a need for methods and apparatus for rapid and accurate analysis of diffraction data to determine the profiles of periodic gratings.
Additional objects and advantages of the present application will become apparent upon review of the Figures, Detailed Description of the Present Invention, and appended Claims.
SUMMARY OF THE INVENTION
The present invention is directed to a method for reducing the computation time of rigorous coupled-wave analyses (RCWA) of the diffraction of electromagnetic radiation from a periodic grating. RCWA calculations involve the division of the periodic grating into layers, with the initial layer being the atmospheric space above the grating, the last layer being the substrate below the grating, and the periodic features of the grating lying in intermediate layers between the atmospheric space and the substrate. A cross-section of the periodic features is discretized into a plurality of stacked rectangular sections, and within each layer the permittivity, and the electric and magnetic fields of the radiation are formulated as a sum of harmonic components along the direction of periodicity of the grating.
Application of Maxwell's equations provides an intra-layer matrix equation in each of the intermediate layers l of the form
[ ∂ 2 S l , y ∂ z ′2 ] = [ A l ] [ S l , y ]
where S l,y are harmonic amplitudes of an electromagnetic field, z is the perpendicular to the periodic grating, and the wave-vector matrix A l is only dependent on intra-layer parameters and incident-radiation parameters. A homogeneous solution of the intra-layer matrix equation involves an expansion of the harmonic amplitudes S l,y into exponential functions dependent on eigenvectors and eigenvalues of said wave-vector matrix A l .
According to the present invention, a layer-property parameter region, an incident-radiation parameter region, a layer-property parameter-region sampling, and an incident-radiation parameter-region sampling are determined. Also, a maximum harmonic order to which the electromagnetic fields are to be computed is determined. The required permittivity harmonics are calculated for each layer-property value, as determined by the layer-property parameter-region sampling of the layer-property parameter region. The wave-vector matrix A and its eigenvectors and eigenvalues are calculated for each layer-property value and each incident-radiation value, as determined by the incident-radiation parameter-region sampling of the incident-radiation parameter region. The calculated eigenvectors and eigenvalues are stored in a memory for use in analysis of the diffraction of incident electromagnetic radiation from the periodic grating.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a section of a diffraction grating labeled with variables used in the mathematical analysis of the present invention.
FIG. 2 shows a cross-sectional view of a pair of ridges labeled with dimensional variables used in the mathematical analysis of the present invention.
FIG. 3 shows a process flow of a TE-polarization rigorous coupled-wave analysis.
FIG. 4 shows a process flow for a TM-polarization rigorous coupled-wave analysis.
FIG. 5 shows a process flow for the pre-computation and caching of calculation results dependent on intra-layer and incident-radiation parameters according to the method of the present invention.
FIG. 6 shows a process flow for the use of cached calculation results dependent on intra-layer and incident-radiation parameters according to the method of the present invention.
FIG. 7A shows an exemplary ridge profile which is discretized into four stacked rectangular sections.
FIG. 7B shows an exemplary ridge profile which is discretized into three stacked rectangular sections, where the rectangular sections have the same dimensions and x-offsets as three of the rectangular section found in the ridge discretization of FIG. 7 A.
FIG. 8 shows a computation system for implementation of the computation portion of present invention.
FIG. 9 is a flowchart depicted the sequence of events for the implementation of the method of the present invention.
FIG. 10 shows an apparatus for producing radiation incident on a periodic grating and monitoring the radiation diffracted from the periodic grating.
FIG. 11 shows an apparatus for producing radiation incident on a periodic grating and monitoring the radiation diffracted from the periodic grating at two angles of incidence and diffraction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The method and apparatus of the present invention dramatically improves the performance and efficiency for metrology of profiles of one-dimensionally or two-dimensionally repeating, regularly-spaced series of structures by reducing the computation time required for RCWA computations by pre-processing and caching intra-layer information and incident-radiation information, and using the cached intra-layer and incident-radiation information for RCWA calculations.
Section 1 of the present Detailed Description describes apparatus and methods for the acquisition of diffraction data from one-dimensionally and two-dimensionally repeating, regularly-spaced series of structures using optical metrology.
Section 2 of the present Detailed Description describes the mathematical formalism for RCWA calculations for the diffraction of TE-polarized incident radiation from a periodic grating. Definitions of the variables used in the present specification are provided, and intra-layer Fourier-space versions of Maxwell's equations are presented and solved, producing z-dependent electromagnetic-field harmonic amplitudes, where z is the direction normal to the grating. Formulating the electromagnetic-field harmonic amplitudes in each layer as exponential expansions produces an eigenequation for a wave-vector matrix dependent only on intra-layer parameters and incident-radiation parameters. Coefficients and exponents of the exponential harmonic amplitude expansions are functions of the eigenvalues and eigenvectors of the wave-vector matrices. Application of inter-layer boundary conditions produces a boundary-matched system matrix equation, and the solution of the boundary-matched system matrix equation provides the remaining coefficients of the harmonic amplitude expansions.
Section 3 of the present Detailed Description describes mathematical formalisms for RCWA calculations of the diffracted reflectivity of TM-polarized incident radiation which parallels the exposition of Section 1.
Section 4 of the present Detailed Description presents a preferred method for the solution of the boundary-matched system matrix equation.
Section 5 of the present Detailed Description describes the method and apparatus of the present invention. Briefly, the pre-calculation/caching portion of the method of the present invention involves:
a selection of an intra-layer parameter region, an intra-layer parameter sampling, an incident-radiation parameter region, and an incident-radiation parameter sampling; generation of wave-vector matrices for intra-layer parameters spanning the intra-layer parameter region, as determined by the intra-layer parameter sampling, and incident-radiation parameters spanning the incident-radiation parameter region, as determined by the incident-radiation parameter sampling; solution for the eigenvectors and eigenvalues of the wave-vector matrices in the investigative region; and caching of the eigenvectors and eigenvalues of the wave-vector matrices.
Briefly, the portion of the method of the present invention for the use of the cached computations to calculate the diffracted reflectivity produced by a periodic grating includes the steps of:
discretization of the profile of a ridge of the periodic grating into layers of rectangular slabs; retrieval from cache of the eigenvectors and eigenvalues for the wave-vector matrix corresponding to each layer of the profile; compilation of the retrieved eigenvectors and eigenvalues for each layer to produce a boundary-matched system matrix equation; and solution of the boundary-matched system matrix equation to provide the diffracted reflectivity.
Section 6 of the present Detailed Description describes the matching methodology used in comparing a measured diffraction spectrum to entries in a library of profile-spectra pairs, in order to determine the profile corresponding to the measured diffraction spectrum.
A flowchart for the complete sequence of events for the present invention is shown in FIG. 9 . First, diffraction signals are acquired 905 by an optical setup, using either a reflectometry or an ellipsometry configuration, as described below and depicted in FIGS. 10 and 11 . Then, numerical aperture of the focusing optics in the optical path of the reflectometry or ellipsometry configuration are characterized 910 , in order to determine the range of incidence angles that need to be taken into account in the calculation of the simulated diffraction spectra. Next, a sub-library of profile shapes is constructed 915 based on a range and a sampling of intra-layer parameters characterizing the profiles. Intra-layer dependent portions of the rigorous coupled-wave calculation are then pre-computed 920 for the selected range and sampling of intra-layer parameters, and cached 925 in a memory. Then, using the pre-computed and cached intra-layer dependent portions of the rigorous coupled-wave calculation, diffraction spectra are calculated 930 for each profile in the sub-library, to produce a sub-library of spectra. The sub-library of profiles is then indexed 935 with the sub-library of spectra to provide a library of profile-spectra pairs. Finally, a measured diffraction spectrum obtained from a physical profile is compared 940 to the spectra in the library, in order to determine the best-matched calculated spectrum. The profile corresponding to the best-matched calculated spectrum is the calculated estimate of the physical profile.
1. Acquisition of Diffraction Data
As shown in FIG. 10 , the incident beam ( 1010 ) is generated by an excitation head ( 1020 ) of an ellipsometer ( 1030 ). The incident beam ( 1010 ) consists of radiation having two polarizations to allow measurement of both intensity and phase of the diffracted electromagnetic radiation ( 1011 ) monitored by an optical detector ( 1070 ). An optical fiber ( 1025 ) transports white light from a source (not shown) to the excitation head ( 1020 ). The white light could either be polarized light or unpolarized light. The incident beam ( 1010 ) is directed onto a sample ( 1045 ) mounted on a workpiece ( 1040 ) such that the angle of incidence θ measured from the normal {right arrow over (n)} of the sample ( 1045 ) is between 20 and 90 degrees, more preferrably between 30 and 80 degrees, still more preferrably between 40 and 75 degrees, still more preferrably between 50 and 70 degrees. The reason the range from 50 and 70 degrees is preferred is because angles in that range have been found to generally be most sensitive for the metrology of grating materials typically found in semiconductor processing. Most preferrably, the angle of incidence θ is near the Brewster's angle, i.e., the angle such that the sum of the incident and reflected angles is 90 degrees. When the radiation ( 1010 ) is incident at the Brewster's angle, the diffracted radiation ( 1011 ) consists of only a single polarization. The workpiece ( 1040 ) can be placed on either a chill plate, a hot plate or the developer module (these modules will henceforth be referred collectively as the process plate and assigned the reference numeral ( 1080 )) on the wafer track, or in the end chamber of an etcher, or in an end-station or metrology station in a chemical mechanical polishing tool. The reflected beam ( 1011 ) leaves the workpiece ( 1040 ) at an angle θ which is equal to the angle of incidence θ, but on the opposite side of the normal {right arrow over (n)}. In the case that the apparatus ( 1030 ) of FIG. 10 is a spectrometer, then the diffracted radiation ( 1015 ) is received by the detector ( 1070 ) which separates the spectra into two polarizations before passing the signal to a spectrometer ( 1090 ) via an optical fiber ( 1027 ). In the case that the apparatus ( 1030 ) of FIG. 10 is a reflectometer, the diffracted radiation ( 1015 ) is sent directly to the spectrometer ( 1090 ) via the optical fiber ( 1026 ). The spectrometer ( 1090 ) then sends the signal to either a charge coupled device (not shown) or a photomultiplier (not shown) which converts the optical signal to ah electrical signal which enters a signal processor, such as the analysis processor of the present invention depicted in FIG. 8 and described in detail below. In the case that the apparatus ( 1030 ) of FIG. 10 is an ellipsometer, angles Δ and Ψ are determined from the numerical signal processing system of FIG. 8 . As discussed above, the magnitude of the diffracted radiation ( 1071 ) provides Ψ, and the relative phase of the two polarizations provides Δ. In the case that the apparatus ( 1030 ) of FIG. 10 is a reflectometer, the relative intensity is measured.
According to another preferred embodiment of the present invention for a diffraction data acquisition system, the broadband ellipsometry or reflectometry apparatus ( 1030 ) of FIG. 10 is modified to include focusing optics to reduce the spot size to less than the size of the test area. Typically, such focusing optics produce illumination regions of 50 μm×50 μm, or smaller, and utilize a pattern recognition module to center the spot in the test area.
According to the present invention, a diffraction data acquisition system may utilize multiple detectors and multiple excitation heads. For instance, as shown in FIG. 11 , the system ( 1030 ′) may utilize two excitation heads ( 1020 a ) and ( 1020 b ), and two detectors ( 1070 a ) and ( 1070 b ). Two broadband incident beams ( 1110 a ) and ( 1110 b ) are generated by excitation heads ( 1120 a ) and ( 1120 b ), with each incident beam ( 1110 a ) and ( 1110 b ) including two polarizations of the electromagnetic wave to allow for both intensity and phase measurements. As with the single excitation head ( 1020 ) apparatus ( 1030 ) of FIG. 10 , an optical fiber ( 1025 ) transports broadband radiation from a source (not shown) to the two excitation heads ( 1120 a ) and ( 1120 b ). A switching mechanism ( 1099 ) directs the broadband radiation alternately to the two optic fiber branches ( 1025 a ) and ( 1025 b ) which lead to the two excitation heads ( 1020 a ) and ( 1020 b ), respectively. In the preferred embodiment, the switching mechanism ( 1099 ) is a wheel with an opening in one semicircle, so that rotation of the switching wheel ( 1099 ) by 180 degrees produces a switching of the optic fiber branch ( 1025 a ) or ( 1025 b ) to which the radiation is directed. According to the preferred embodiment of the present invention, the incident beams are directed to workpiece ( 1140 ) so that the angles of incidence θ 1 and θ 2 are approximately 50 and 70 degrees. Other angles of incidence are also contemplated as useful, depending on the workpiece, and angles between zero and 90 degrees are possible. Since ellipsometric measurements are made for two angles of incidence θ 1 and θ 2 , the angles θ 1 and θ 2 are chosen to be disparate enough that redundancy of information is not an issue, while both θ 1 and θ 2 are chosen to be close enough to Brewster's angle that the incident beam is sensitive to the grating features. The diffracted beams ( 1015 a ) and ( 1015 b ) leave the workpiece at angles θ 1 and θ 2 , which are equal to the angles of incidence θ 1 and θ 2 , but to the opposite side of the normal {right arrow over (n)}. The diffracted beams ( 1015 a ) and ( 1015 b ) are received by detectors ( 1070 a ) and ( 1070 b ). In the case that the apparatus ( 1030 ′) of FIG. 11 is a spectrometer, the diffracted radiation ( 1015 a ) and ( 1015 b ) is received by detectors ( 1070 a ) and ( 1070 b ) which each separates the diffracted radiation ( 1015 a ) and ( 1015 b ) into two polarizations before passing the signal to a spectrometer ( 1090 ) via an optical fiber ( 1027 ). In the case that the apparatus ( 1030 ) of FIG. 10 is a reflectometer, then the diffracted radiation ( 1011 ) is sent directly to the spectrometer ( 1090 ) via an optical fiber ( 1027 ). The spectrometer ( 1090 ) sends the signal to either a charge coupled device (not shown) or a photomultiplier (not shown) which converts the optical signal to an electrical signal which enters a signal processor, such as the analysis processor of the present invention depicted in FIG. 8 and described in detail below. In the case that the apparatus ( 1030 ′) of FIG. 11 is an ellipsometer, angles Δ and Ψ as a function of frequency are determined from the numerical signal processing system of FIG. 8 . In the case that the apparatus ( 1030 ′) of FIG. 11 is a reflectometer, the relative intensity is measured. It should be understood that multiple detectors ( 1070 a ) and ( 1070 b ) are not necessary to perform multiple-angle reflectometry or ellipsometry measurements since the excitation head ( 1020 ) and detector ( 1070 ) may perform a first measurement for an angle of incidence of θ 1 , and then be moved to perform a second measurement for an angle of incidence of θ 2 . Furthermore, a focusing lenses may be included in the optical path of the apparatuses of FIGS. 10 or 11 to produce an area of incidence which small enough to meet test-area restrictions.
2. Rigorous Coupled-Wave Analysis for TE-Polarized Incident Radiation
A section of a periodic grating ( 100 ) is shown in FIG. 1 . The section of the grating ( 100 ) which is depicted includes three ridges ( 121 ) which are shown as having a triangular cross-section. It should be noted that the method of the present invention is applicable to cases where the ridges have shapes which are considerably more complex, and even to cases where the categories of “ridges” and “troughs” may be ill-defined. According to the lexography of the present specification, the term “ridge” will be used for one period of a periodic structure on a substrate. Each ridge ( 121 ) of FIG. 1 is considered to extend infinitely in the +y and −y directions, and an infinite, regularly-spaced series of such ridges ( 121 ) are considered to extend in the +x and −x directions. The ridges ( 121 ) are atop a deposited film ( 110 ), and the film ( 110 ) is atop a substrate ( 105 ) which is considered to extend semi-infinitely in the +z direction. The normal vector {right arrow over (n)} to the grating is in the −z direction.
FIG. 1 illustrates the variables associated with a mathematical analysis of a diffraction grating according to the present invention. In particular:
θ is the angle between the Poynting vector ( 130 ) of the incident electromagnetic radiation ( 131 ) and the normal vector {right arrow over (n)} of the grating ( 100 ). The Poynting vector ( 130 ) and the normal vector {right arrow over (n)} define the plane of incidence ( 140 ). φ is the azimuthal angle of the incident electromagnetic radiation ( 131 ), i.e., the angle between the direction of periodicity of the grating, which in FIG. 1 is along the x axis, and the plane of incidence ( 140 ). (For ease of presentation, in the mathematical analysis of the present specification the azimuthal angle φ is set to zero.) Ψ is the angle between the electric-field vector {right arrow over (E)} of the incident electromagnetic radiation ( 131 ) and the plane of incidence ( 140 ), i.e., between the electric field vector {right arrow over (E)} and its projection {right arrow over (E)}′ on the plane of incidence ( 140 ). When φ=0 and the incident electromagnetic radiation ( 131 ) is polarized so that Ψ=π/2, the electric-field vector {right arrow over (E)} is perpendicular to the plane of incidence ( 140 ) and the magnetic-field vector {right arrow over (H)} lies in the plane of incidence ( 140 ), and this is referred to as the TE polarization. When φ=0 and the incident electromagnetic radiation ( 131 ) is polarized so that Ψ=0, the magnetic-field vector {right arrow over (H)} is perpendicular to the plane of incidence ( 140 ) and the electric-field vector {right arrow over (E)} lies in the plane of incidence ( 140 ), and this is referred to as the TM polarization. Any planar polarization is a combination of in-phase TE and TM polarizations. The method of the present invention described below can be applied to any polarization which is a superposition of TE and TM polarizations by computing the diffraction of the TE and TM components separately and summing them. Furthermore, although the ‘off-axis’ φ≠0 case is more complex because it cannot be separated into TE and TM components, the present invention is applicable to off-axis incidence radiation as well. λ is the wavelength of the incident electromagnetic radiation ( 131 ).
FIG. 2 shows a cross-sectional view of two ridges ( 121 ) of an exemplary periodic grating ( 100 ) (which will be labeled using the same reference numerals as the grating of FIG. 1 .), illustrating the variables associated with a mathematical description of the dimensions of the diffraction grating ( 100 ) according to the present invention. In particular:
L is the number of the layers into which the system is divided. Layers 0 and L are considered to be semi-infinite layers. Layer 0 is an “atmospheric” layer ( 101 ), such as vacuum or air, which typically has a refractive index n 0 of unity. Layer L is a “substrate” layer ( 105 ), which is typically silicon or germanium in semiconductor applications. In the case of the exemplary grating 100 of FIG. 2 , the grating ( 100 ) has ten layers with the atmospheric layer ( 101 ) being the zeroeth layer ( 125 . 0 ), the ridges ( 121 ) being in the first through seventh layers ( 125 . 1 ) through ( 125 . 7 ), the thin film ( 110 ) being the eighth layer ( 125 . 8 ), and the substrate ( 105 ) being the ninth layer ( 125 . 9 ). (For the mathematical analysis described below, the thin-film ( 110 ) is considered as a periodic portion of the ridge ( 121 ) with a width d equal to the pitch D.) The portion of ridge ( 121 ) within each intermediate layer ( 125 . 1 ) through ( 125 .(L−1)) is approximated by a thin planar slab ( 126 ) having a rectangular cross-section. (Generically or collectively, the layers are assigned reference numeral ( 125 ), and, depending on context, “layers ( 125 )” may be considered to include the atmospheric layer ( 101 ) and/or the substrate ( 105 ).) In general, any geometry of ridges ( 121 ) with a cross-section which does not consist solely of vertical and horizontal sections can be better approximated using a large number of layers ( 125 ). D is the periodicity length or pitch, i.e., the length between equivalent points on pairs of adjacent ridges ( 121 ). d l is the width of the rectangular ridge slab ( 126 . l ) in the lth layer ( 125 . l ). t l is the thickness of the rectangular ridge slab ( 126 . l ) in the lth layer ( 125 . l ) for 1<l<(L−1). The thicknesses t l of the layers ( 125 ) are chosen such that every vertical line segment within a layer ( 125 ) passes through only a single material. For instance, if in FIG. 2 the materials in layers ( 125 . 4 ), ( 125 . 5 ), and ( 125 . 6 ) are the same, but different than the materials in layers ( 125 . 3 ) and ( 125 . 7 ), than it would be acceptable to combine layers ( 125 . 4 ) and ( 125 . 5 ), or layers ( 125 . 5 ) and ( 125 . 6 ), or layers ( 125 . 4 ), ( 125 . 5 ) and ( 125 . 6 ) into a single layer. However, it would not be acceptable to combine layers ( 125 . 3 ) and ( 125 . 4 ), or layers ( 125 . 6 ) and ( 125 . 7 ) into a single layer. n l is the index of refraction of the material in the rectangular ridge slab ( 126 ) of the lth layer ( 125 . l ).
In determining the diffraction generated by grating ( 100 ), a Fourier space version of Maxwell's equations is used. As shown in the calculation process flow diagram of FIG. 3 , the permittivities ε l (x) for each layer l are determined or acquired ( 310 ) (for instance, according to the method described in provisional patent application Ser. No. 60/178,540, filed Jan. 26, 2000, entitled Profiler Business Model, by the present inventors, and provisional patent application Ser. No. 60/209,424, filed Jun. 2, 2000, entitled Profiler Business Model, by the present inventors, both of which are incorporated herein by reference), and a one-dimensional Fourier transformation of the permittivity ε l (x) of each layer l is performed ( 312 ) along the direction of periodicity, {circumflex over (x)}, of the periodic grating ( 100 ) to provide the harmonic components of the permittivity ε l,i , where i is the order of the harmonic component. (In FIGS. 3 , 4 , 5 and 6 , process steps are shown enclosed within ovals or rectangles with rounded corners, and the results of calculations are shown enclosed within rectangles with sharp corners. When appropriate in FIG. 3 , equation numbers are used in lieu of, or in addition to, reference numerals.) In particular, the real-space permittivity ε l (x) of the lth layer is related to the permittivity harmonics ε l,i of the lth layer by
ɛ l ( x ) = ∑ i = - ∞ ∞ ɛ l , i exp ( j 2 π ⅈ D x ) . ( 1.1 .1 )
Therefore, via the inverse transform,
ɛ l , 0 = n r 2 d l D + n 0 2 ( 1 - d l D ) , ( 1.1 .2 )
and for i not equal to zero,
ɛ l , i = ( n r 2 - n 0 2 ) sin ( π ⅈ d l D ) π ⅈ ⅇ - jπ i β / D , ( 1.1 .3 )
where n r is the index of refraction of the material in the ridges ( 121 ) in layer l, the index of refraction n 0 of the atmospheric layer ( 101 ) is typically near unity, and β is the x-offset of the center of the central rectangular ridge slab ( 126 . l ) (i.e., the ridge ( 121 ) nearest x=0, where generally it is attempted to position the x=0 point at the center of a ridge ( 121 )) from the origin. The present specification explicitly addresses periodic gratings where a single ridge material and a single atmospheric material are found along any line in the x-direction. However, as per disclosure document serial number 474051, filed May 15, 2000, entitled Optical Profilometry for Sub-Micron Periodic Features with Three or More Materials in a Layer, by the same inventors, the present invention may be applied to gratings having more than one ridge material along a line in the x-direction.
According to the mathematical formulation of the present invention, it is convenient to define the (2o+1)×(2o+1) Toeplitz-form, permittivity harmonics matrix E l as
E l = [ ɛ l , 0 ɛ l , - 1 ɛ l , - 2 ⋯ ɛ l , - 2 o ɛ l , 1 ɛ l , 0 ɛ l , - 1 ⋯ ɛ l , - ( 2 o - 1 ) ɛ l , 2 ɛ l , 1 ɛ l , 0 ⋯ ɛ l , - ( 2 o - 2 ) ⋯ ⋯ ⋯ ⋯ ⋯ ɛ l , 2 o ɛ l , ( 2 o - 1 ) ɛ i , ( 2 o - 2 ) ⋯ ɛ l , 0 ] . ( 1.1 .4 )
As will be seen below, to perform a TE-polarization calculation where oth-order harmonic components of the electric field {right arrow over (E)} and magnetic field {right arrow over (H)} are used, it is necessary to use harmonics of the permittivity ε l,i up to order 2o.
For the TE polarization, in the atmospheric layer the electric field {right arrow over (E)} is formulated ( 324 ) as
E -> 0 , y = exp ( - j k 0 n 0 ( sin θ x + cos θ z ) + ∑ i R i exp ( - j ( k xi x - k 0 , zi z ) ) , ( 1.2 .1 )
where the term on the left of the right-hand side of equation (1.2.1) is an incoming plane wave at an angle of incidence θ, the term on the right of the right-hand side of equation (1.2.1) is a sum of reflected plane waves and R i is the magnitude of the ith component of the reflected wave, and the wave vectors k 0 and (k xi , k 0,zi ) are given by
k 0 = 2 π λ = ω ( μ 0 ɛ 0 ) 1 / 2 , ( 1.2 .2 ) k xi = k 0 ( n 0 sin ( θ ) - ⅈ ( λ D ) ) ,
and ( 1.2 .3 ) k 0 , zi = { k 0 ( n l 2 - ( k xi / k 0 ) 2 ) 1 / 2 - j k 0 ( n l 2 - ( k xi / k 0 ) 2 ) 1 / 2 ( 1.2 .4 )
where the value of k 0,zi is chosen from equation (1.2.4), i.e., from the top or the bottom of the expression, to provide Re(k 0,zi )−Im(k 0,zi )>0. This insures that k 0,zi 2 has a positive real part, so that energy is conserved. It is easily confirmed that in the atmospheric layer ( 101 ), the reflected wave vector (k xi , k 0,zi ) has a magnitude equal to that of the incoming wave vector k 0 n 0 . The magnetic field {right arrow over (H)} in the atmospheric layer ( 101 ) is generated from the electric field {right arrow over (E)} by Maxwell's equation (1.3.1) provided below.
The x-components k xi of the outgoing wave vectors satisfy the Floquet condition (which is also called Bloch's Theorem, see Solid State Physics, N. W. Ashcroft and N. D. Mermin, Saunders College, Philadelphia, 1976, pages 133-134) in each of the layers ( 125 ) containing the periodic ridges ( 121 ), and therefore, due to the boundary conditions, in the atmospheric layer ( 101 ) and the substrate layer ( 105 ) as well. That is, for a system having an n-dimensional periodicity given by
f ( r -> ) = f ( r -> + ∑ i = 1 n m i d -> i ) , ( 1.2 .5 )
where {right arrow over (d)} i are the basis vectors of the periodic system, and m i takes on positive and negative integer values, the Floquet condition requires that the wave vectors {right arrow over (k)} satisfy
k -> = k -> 0 + 2 π ∑ i = 1 n m i b -> i , ( 1.2 .6 )
where {right arrow over (b)} i are the reciprocal lattice vectors given by
( {right arrow over (b)} i ·{right arrow over (d)} j )=δ ij , (1.2.7)
{right arrow over (k)} 0 is the wave vector of a free-space solution, and δ ij is the Kronecker delta function. In the case of the layers ( 125 ) of the periodic grating ( 100 ) of FIGS. 1 and 2 which have the single reciprocal lattice vector {right arrow over (b)} is {circumflex over (x)}/D, thereby providing the relationship of equation (1.2.3).
It may be noted that the formulation given above for the electric field in the atmospheric layer ( 101 ), although it is an expansion in terms of plane waves, is not determined via a Fourier transform of a real-space formulation. Rather, the formulation is produced ( 324 ) a priori based on the Floquet condition and the requirements that both the incoming and outgoing radiation have wave vectors of magnitude n 0 k 0 . Similarly, the plane wave expansion for the electric field in the substrate layer ( 105 ) is produced ( 324 ) a priori. In the substrate layer ( 105 ), the electric field {right arrow over (E)} is formulated ( 324 ) as a transmitted wave which is a sum of plane waves where the x-components k xi of the wave vectors (k xi , k 0,zi ) satisfy the Floquet condition, i.e.,
E -> L , y = ∑ i T i exp ( - j ( k xi x + k L , zi ( z - ∑ l = 1 L - 1 t l ) ) ) , ( 1.2 .8 ) where k L , zi = { k 0 ( n L 2 - ( k xi / k 0 ) 2 ) 1 / 2 - j k 0 ( n L 2 - ( k xi / k 0 ) 2 ) 1 / 2 ( 1.2 .9 )
where the value of k L,zi is chosen from equation (1.2.9), i.e., from the top or the bottom of the expression, to provide Re(k L,zi )−Im(k L,zi )>0, insuring that energy is conserved.
The plane wave expansions for the electric and magnetic fields in the intermediate layers ( 125 . 1 ) through ( 125 .(L−1)) are also produced ( 334 ) a priori based on the Floquet condition. The electric field {right arrow over (E)} l,y in the lth layer is formulated ( 334 ) as a plane wave expansion along the direction of periodicity, {circumflex over (x)}, i.e.,
E -> l , y = ∑ i S l , yi ( z ) exp ( - j k xi x ) , ( 1.2 .10 )
where S l,yi (z) is the z-dependent electric field harmonic amplitude for the lth layer and the ith harmonic. Similarly, the magnetic field {right arrow over (H)} l,y in the lth layer is formulated ( 334 ) as a plane wave expansion along the direction of periodicity, {circumflex over (x)}, i.e.,
H -> l , x = - j ( ɛ 0 μ 0 ) 1 / 2 ∑ i U l , xi ( z ) exp ( - j k xi x ) , ( 1.2 .11 )
where U l,xi (z) is the z-dependent magnetic field harmonic amplitude for the lth layer and the ith harmonic.
According to Maxwell's equations, the electric and magnetic fields within a layer are related by
H -> l = ( j ω μ 0 ) ∇ × E -> l , ( 1.3 .1 ) and E -> l = ( - j ω ɛ 0 ɛ l ( x ) ) ∇ × H -> l . ( 1.3 .2 )
Applying ( 342 ) the first Maxwell's equation (1.3.1) to equations (1.2.10) and (1.2.11) provides a first relationship between the electric and magnetic field harmonic amplitudes S l and U l of the lth layer:
∂ S l , yi ( z ) ∂ z = k 0 U l , xi . ( 1.3 .3 )
Similarly, applying ( 341 ) the second Maxwell's equation (1.3.2) to equations (1.2.10) and (1.2.11), and taking advantage of the relationship
k xi + 2 π h D = k x ( i - h ) ( 1.3 .4 )
which follows from equation (1.2.3), provides a second relationship between the electric and magnetic field harmonic amplitudes S l and U l for the lth layer:
∂ U l , xi ∂ z = ( k xi 2 k 0 ) S l , yi - k 0 ∑ p ɛ ( i - p ) S l , yp . ( 1.3 .5 )
While equation (1.3.3) only couples harmonic amplitudes of the same order i, equation (1.3.5) couples harmonic amplitudes S l and U l between harmonic orders. In equation (1.3.5), permittivity harmonics ε i from order −2o to +2o are required to couple harmonic amplitudes S l and U l of orders between −o and +o.
Combining equations (1.3.3) and (1.3.5) and truncating the calculation to order o in the harmonic amplitude S provides ( 345 ) a second-order differential matrix equation having the form of a wave equation, i.e.,
[ ∂ 2 S l , y ∂ z ′2 ] = [ A l ] [ S l , y ] , ( 1.3 .6 )
z′=k 0 z, the wave-vector matrix [A l ] is defined as
[ A l ]=[K x ] 2 −[E l ], (1.3.7)
where [K x ] is a diagonal matrix with the (i,i) element being equal to (k xi /k 0 ), the permittivity harmonics matrix [E l ] is defined above in equation (1.1.4), and [S l,y ] and [∂ 2 S l,y /∂z′ 2 ] are column vectors with indices i running from −o to +o, i.e.,
[ S l , y ] = [ S l , y , ( - o ) ⋮ S l , y , 0 ⋮ S l , y , o ] , ( 1.3 .8 )
By writing ( 350 ) the homogeneous solution of equation (1.3.6) as an expansion in pairs of exponentials, i.e.,
S l , yi ( z ) = ∑ m = 1 2 o + 1 w l , i , m [ c1 l , m exp ( - k 0 q l , m z ) + c2 l , m exp ( k 0 q l , m ( z - t l ) ) ] , ( 1.3 .9 )
its functional form is maintained upon second-order differentiation by z′, thereby taking the form of an eigenequation. Solution ( 347 ) of the eigenequation
[A l ][W l ]=[τ l ][W l ], (1.3.10)
provides ( 348 ) a diagonal eigenvalue matrix [τ l ] formed from the eigenvalues τ l,m of the wave-vector matrix [A l ], and an eigenvector matrix [W l ] of entries w l,i,m , where w l,i,m is the ith entry of the mth eigenvector of [A l ]. A diagonal root-eigenvalue matrix [Q l ] is defined to be diagonal entries q l,i which are the positive real portion of the square roots of the eigenvalues τ l,i . The constants c1 and c2 are, as yet, undetermined.
By applying equation (1.3.3) to equation (1.3.9) it is found that
U l , xi ( z ) = ∑ m = 1 2 o + 1 v l , i , m [ - c1 l , m exp ( - k 0 q l , m z ) + c2 l , m exp ( k 0 q l , m ( z - t l ) ) ] ( 1.3 .11 )
where v l,i,m =q l,m w l,i,m . The matrix [V l ], to be used below, is composed of entries v l,i,m .
The constants c1 and c2 in the homogeneous solutions of equations (1.3.9) and (1.3.11) are determined by applying ( 355 ) the requirement that the tangential electric and magnetic fields be continuous at the boundary between each pair of adjacent layers ( 125 . l )/( 125 .(l+1)). At the boundary between the atmospheric layer ( 101 ) and the first layer ( 125 . 1 ), continuity of the electric field E y and the magnetic field H x requires
[ δ i0 j n 0 cos ( θ ) δ i0 ] + [ I - j Y 0 ] R = [ W 1 W 1 X 1 V 1 - V 1 X 1 ] [ c1 1 c2 1 ] ( 1.4 .1 )
where Y 0 is a diagonal matrix with entries (k 0,zi /k 0 ), X l is a diagonal layer-translation matrix with elements exp(−k 0 q l,m t l ), R is a vector consisting of entries from R −0 to R +o and c1 1 and c2 l are vectors consisting of entries from c1 1,0 and c1 1,2o÷1 , and c2 1,0 and c2 1,2o+1 , respectively. The top half of matrix equation (1.4.1) provides matching of the electric field E y across the boundary of the atmospheric layer ( 125 . 0 ) and the first layer ( 125 . 1 ), the bottom half of matrix equation (1.4.1) provides matching of the magnetic field H x across the layer boundary ( 125 . 0 )/( 125 . 1 ), the vector on the far left is the contribution from the incoming radiation ( 131 ) in the atmospheric layer ( 101 ), the second vector on the left is the contribution from the reflected radiation ( 132 ) in the atmospheric layer ( 101 ), and the portion on the right represents the fields E y and H x in the first layer ( 125 . 1 ).
At the boundary between adjacent intermediate layers ( 125 . l ) and ( 125 .(l+1)), continuity of the electric field E y and the magnetic field H x requires
[ W l - 1 X l - 1 W l - 1 W l - 1 X l - 1 - V l - 1 ] [ c1 l - 1 c2 l - 1 ] = [ W l W l X l V l - V l X l ] [ c1 l c2 l ] , ( 1.4 .2 )
where the top and bottom halves of the vector equation provide matching of the electric field E y and the magnetic field H x , respectively, across the l−1/l layer boundary.
At the boundary between the (L−1)th layer 125 .(L−1) and the substrate layer ( 105 ), continuity of the electric field E y and the magnetic field H x requires
[ W L - 1 X L - 1 W L - 1 V L - 1 X L - 1 - V L - 1 ] [ c1 L - 1 c2 L - 1 ] = [ I j Y L ] T , ( 1.4 .3 )
where, as above, the top and bottom halves of the vector equation provides matching of the electric field E y and the magnetic field H x , respectively. In contrast with equation (1.4.1), there is only a single term on the right since there is no incident radiation in the substrate ( 105 ).
Matrix equation (1.4.1), matrix equation (1.4.3), and the (L−1) matrix equations (1.4.2) can be combined ( 360 ) to provide a boundary-matched system matrix equation
[ - I W 1 W 1 X 1 0 0 ⋯ j Y 0 V 1 - VX 0 0 ⋯ 0 - W 1 X 1 - W 1 W 2 W 2 X 2 0 0 ⋯ 0 - V 1 X 1 V 1 V 2 - V 2 X 2 0 0 ⋯ 0 0 0 0 ⋰ ⋰ ⋮ ⋯ - W L - 1 X L - 1 - W L - 1 I - V L - 1 X L - 1 V L - 1 j Y L ] [ R c1 1 c2 1 ⋮ ⋮ c1 L - 1 c2 L - 1 T ] = [ δ i0 j δ i0 n 0 cos ( θ ) 0 ⋮ ⋮ 0 ] , ( 1.4 .4 )
and this boundary-matched system matrix equation (1.4.4) may be solved ( 365 ) to provide the reflectivity R i for each harmonic order i. (Alternatively, the partial-solution approach described in “Stable Implementation of the Rigorous Coupled-Wave Analysis for Surface-Relief Dielectric Gratings: Enhanced Transmittance Matrix Approach”, E. B. Grann and D. A. Pommet, J. Opt. Soc. Am. A , vol. 12, 1077-1086, May 1995, can be applied to calculate either the diffracted reflectivity R or the diffracted transmittance T.)
3. Rigorous Coupled-Wave Analysis for the TM Polarization
The method ( 400 ) of calculation for the diffracted reflectivity of TM-polarized incident electromagnetic radiation ( 131 ) shown in FIG. 4 parallels that ( 300 ) described above and shown in FIG. 3 for the diffracted reflectivity of TE-polarized incident electromagnetic radiation ( 131 ). The variables describing the geometry of the grating ( 100 ) and the geometry of the incident radiation ( 131 ) are as shown in FIGS. 1 and 2 . However, for TM-polarized incident radiation ( 131 ) the electric field vector {right arrow over (E)} is in the plane of incidence ( 140 ), and the magnetic field vector {right arrow over (H)} is perpendicular to the plane of incidence ( 140 ). (The similarity in the TE- and TM-polarization RCWA calculations and the application of the present invention motivates the use of the term ‘electromagnetic field’ in the present specification to refer generically to either or both the electric field and/or the magnetic field of the electromagnetic radiation.)
As above, once the permittivity ε l (x) is determined or acquired ( 410 ), the permittivity harmonics ε l,i are determined ( 412 ) using Fourier transforms according to equations (1.1.2) and (1.1.3), and the permittivity harmonics matrix E l is assembled as per equation (1.1.4). In the case of TM-polarized incident radiation ( 131 ), it has been found that the accuracy of the calculation may be improved by formulating the calculations using inverse-permittivity harmonics π l,i , since this will involve the inversion of matrices which are less singular. In particular, the one-dimensional Fourier expansion ( 412 ) for the inverse of the permittivity ε l (x) of the lth layer is given by
1 ɛ l ( x ) = ∑ h = - ∞ ∞ π l , h exp ( j 2 π h D x ) . ( 2.1 .1 )
Therefore, via the inverse Fourier transform this provides
π l , 0 = 1 n r 2 d l D + 1 n 0 2 ( 1 - d l D ) , ( 2.1 .2 )
and for h not equal to zero,
π l , h = ( 1 n r 2 - 1 n 0 2 ) sin ( π h d l D ) π h ⅇ - j π h β / D , ( 2.1 .3 )
where β is the x-offset of the center of the rectangular ridge slab ( 126 . l ) from the origin. The inverse-permittivity harmonics matrix P l is defined as
P l = [ π l , 0 π l , - 1 π l , - 2 ⋯ π l , - 2 o π l , 1 π l , 0 π l , - 1 ⋯ π l , - ( 2 o - 1 ) π l , 2 π l , 1 π l , 0 ⋯ π l , - ( 2 o - 2 ) ⋯ ⋯ ⋯ ⋯ ⋯ π l , 2 o π l , ( 2 o - 1 ) π l , ( 2 o - 2 ) ⋯ π l , 0 ] , ( 2.1 .4 )
where 2o is the maximum harmonic order of the inverse permittivity π l,h used in the calculation. As with the case of the TE polarization ( 300 ), for electromagnetic fields {right arrow over (E)} and {right arrow over (H)} calculated to order o it is necessary to use harmonic components of the permittivity ε l,h and inverse permittivity π l,h to order 2o.
In the atmospheric layer the magnetic field {right arrow over (H)} is formulated ( 424 ) a priori as a plane wave incoming at an angle of incidence θ, and a reflected wave which is a sum of plane waves having wave vectors (k xi , k 0,zi ) satisfing the Floquet condition, equation (1.2.6). In particular,
H -> 0 , y = exp ( - j k 0 n 0 ( sin θ x + cos θ z ) + ∑ i R i exp ( - j ( k xi x - k 0 , zi z ) ) , ( 2.2 .1 )
where the term on the left of the right-hand side of the equation is the incoming plane wave, and R i is the magnitude of the ith component of the reflected wave. The wave vectors k 0 and (k xi , k 0,zi ) are given by equations (1.2.2), (1.2.3), and (1.2.4) above, and the magnetic field {right arrow over (H)} in the atmospheric layer ( 101 ) is generated from the electric field {right arrow over (E)} by Maxwell's equation (1.3.2). In the substrate layer ( 105 ) the magnetic field {right arrow over (H)} is formulated ( 424 ) as a transmitted wave which is a sum of plane waves where the wave vectors (k xi , k 0,zi ) satisfy the Floquet condition, equation (1.2.6), i.e.,
H -> L , y = ∑ i T i exp ( - j ( k xi x + k L , zi ( z - ∑ l = 1 L - 1 t l ) ) ) , ( 2.2 .2 )
where k L,zi is defined in equation (1.2.9). Again based on the Floquet condition, the magnetic field {right arrow over (H)} l,y in the lth layer is formulated ( 434 ) as a plane wave expansion along the direction of periodicity, {circumflex over (x)}, i.e.,
H -> l , y = ∑ i U l , yi ( z ) exp ( - j k xi x ) , ( 2.2 .3 )
where U l,yi (z) is the z-dependent magnetic field harmonic amplitude for the lth layer and the ith harmonic. Similarly, the electric field {right arrow over (E)} l,x in the lth layer is formulated ( 434 ) as a plane wave expansion along the direction of periodicity, i.e.,
E -> l , x = j ( μ 0 ɛ 0 ) 1 / 2 ∑ i S l , xi ( z ) exp ( - j k xi x ) , ( 2.2 .4 )
where S l,xi (z) is the z-dependent electric field harmonic amplitude for the lth layer and the ith harmonic.
Substituting equations (2.2.3) and (2.2.4) into Maxwell's equation (1.3.2) provides ( 441 ) a first relationship between the electric and magnetic field harmonic amplitudes S l and U l for the lth layer:
∂ [ U l , yi ] ∂ z ′ = [ E l ] [ S l , xi ] . ( 2.3 .1 )
Similarly, substituting (2.2.3) and (2.2.4) into Maxwell's equation (1.3.1) provides ( 442 ) a second relationship between the electric and magnetic field harmonic amplitudes S l and U l for the lth layer:
∂ [ S l , xi ] ∂ z ′ = ( [ K x ] [ P l ] [ K x ] - [ I ] ) [ U l , y ] . ( 2.3 .2 )
where, as above, K x is a diagonal matrix with the (i,i) element being equal to (k xi /k 0 ). In contrast with equations (1.3.3) and (1.3.5) from the TE-polarization calculation, non-diagonal matrices in both equation (2.3.1) and equation (2.3.2) couple harmonic amplitudes S l and U l between harmonic orders.
Combining equations (2.3.1) and (2.3.2) provides a second-order differential wave equation
[ ∂ 2 U l , y ∂ z ′2 ] = { [ E l ] ( [ K x ] [ P l ] [ K x ] - [ I ] ) } [ U l , y ] , ( 2.3 .3 )
where [U l,y ] and [∂ 2 U l,y /∂z′ 2 ] are column vectors with indices running from −o to +o, and o, and the permittivity harmonics [E l ] is defined above in equation (1.1.7), and z′=k 0 z. The wave-vector matrix [A l ] for equation (2.3.3) is defined as
[ A l ]=[E l ]([ K x ][P l ][K x ]−[I ]). (2.3.4)
If an infinite number of harmonics could be used, then the inverse of the permittivity harmonics matrix [E l ] would be equal to the inverse-permittivity harmonics matrix [P l ], and vice versa, i.e., [E l ] −1 =[P l ], and [P l ] −1 =[E l ]. However, the equality does not hold when a finite number o of harmonics is used, and for finite o the singularity of the matrices [E l ] −1 and [P l ], and the singularity of the matrices [P l ] −1 and [E l ], will generally differ. In fact, it has been found that the accuracy of RCWA calculations will vary depending on whether the wave-vector matrix [A l ] is defined as in equation (2.3.4), or
[ A l ]=[P l ] −1 ([ K x ][E l ] −1 [K x ]−[I ]), (2.3.5)
or
[ A l ]=[E l ]([ K x ][E l ] −1 [K x ]−[I ]) (2.3.6)
It should also be understood that although the case where
[ A l ]=[P l ] −1 ([ K x ][P l ][K x ]−[I ]) (2.3.6′)
does not typically provide convergence which is as good as the formulations of equation (2.3.5) and (2.3.6), the present invention may also be applied to the formulation of equation (2.3.6′).
Regardless of which of the three formulations, equations (2.3.4), (2.3.5) or (2.3.6), for the wave-vector matrix [A l ] is used, the solution of equation (2.3.3) is performed by writing ( 450 ) the homogeneous solution for the magnetic field harmonic amplitude U l as an expansion in pairs of exponentials, i.e.,
U l , yi ( z ) = ∑ m = 1 2 o + 1 w l , i , m [ c1 l , m exp ( - k 0 q l , m z ) + c2 l , m exp ( k 0 q l , m ( z - t l ) ) ] . ( 2.3 .7 )
since its functional form is maintained upon second-order differentiation by z′, and equation (2.3.3) becomes an eigenequation. Solution ( 447 ) of the eigenequation
[A l ][W l ]=[τ l ][W l ], (2.3.8)
provides ( 448 ) an eigenvector matrix [W l ] formed from the eigenvectors w l,i of the wave-vector matrix [A l ], and a diagonal eigenvalue matrix [τ l ] formed from the eigenvalues τ l,i of the wave-vector matrix [A l ]. A diagonal root-eigenvalue matrix [Q l ] is formed of diagonal entries q l,i which are the positive real portion of the square roots of the eigenvalues τ l,i . The constants c1 and c2 of equation (2.3.7), are, as yet, undetermined.
By applying equation (1.3.3) to equation (2.3.5) it is found that
S l , xi ( z ) = ∑ m = 1 2 o + 1 v l , i , m [ - c1 l , m exp ( - k 0 q l , m z ) + c2 l , m exp ( k 0 q l , m ( z - t l ) ) ] ( 2.3 .9 )
where the vectors v l,i form a matrix [V l ] defined as
[ V]=[E] −1 [W][Q ] when [A] is defined as in equation (2.3.4), (2.3.10)
[V]=[P][W][Q] when “ ” (2.3.5), (2.3.11)
[ V]=[E] −1 [W][Q ] when “ ” (2.3.6). (2.3.12)
The formulation of equations (2.3.5) and (2.3.11) typically has improved convergence performance (see P. Lalanne and G. M. Morris, “Highly Improved Convergence of the Coupled-Wave Method for TM Polarization”, J. Opt. Soc. Am. A, 779-784,1996; and L. Li and C. Haggans, “Convergence of the coupled-wave method for metallic lamellar diffraction gratings”, J. Opt. Soc. Am. A, 1184-1189, June 1993) relative to the formulation of equations (2.3.4) and (2.3.11) (see M. G. Moharam and T. K. Gaylord, “Rigorous Coupled-Wave Analysis of Planar-Grating Diffraction”, J. Opt. Soc. Am., vol. 71, 811-818, July 1981).
The constants c1 and c2 in the homogeneous solutions of equations (2.3.7) and (2.3.9) are determined by applying ( 455 ) the requirement that the tangential electric and tangential magnetic fields be continuous at the boundary between each pair of adjacent layers ( 125 . l )/( 125 .(l+1)), when the materials in each layer non-conductive. (The calculation of the present specification is straightforwardly modified to circumstances involving conductive materials, and the application of the method of the present invention to periodic gratings which include conductive materials is considered to be within the scope of the present invention. At the boundary between the atmospheric layer ( 101 ) and the first layer ( 125 . 1 ), continuity of the magnetic field H y and the electric field E x requires
[ δ i0 j cos ( θ ) δ i0 / n 0 ] + [ I - j Z 0 ] R = [ W 1 W 1 X 1 V 1 - V 1 X 1 ] [ c1 1 c2 1 ] ( 2.4 .1 )
where Z 0 is a diagonal matrix with entries (k 0,zi /n 0 2 k 0 ), X l is a diagonal matrix with elements exp(−k 0 q l,m t l ), the top half of the vector equation provides matching of the magnetic field H y across the layer boundary, the bottom half of the vector equation provides matching of the electric field E x across the layer boundary, the vector on the far left is the contribution from the incoming radiation ( 131 ) in the atmospheric layer ( 101 ), the second vector on the left is the contribution from the reflected radiation ( 132 ) in the atmospheric layer ( 101 ), and the portion on the right represents the fields H y and E x in the first layer ( 125 . 1 ).
At the boundary between adjacent intermediate layers ( 125 . l ) and ( 125 .(l+1)), continuity of the electric field E y and the magnetic field H x requires
[ W l - 1 X l - 1 W l - 1 W l - 1 X l - 1 - V l - 1 ] [ c1 l - 1 c2 l - 1 ] = [ W l W l X l V l - V l X l ] [ c1 l c2 l ] , ( 2.4 .2 )
where the top and bottom halves of the vector equation provides matching of the magnetic field H y and the electric field E x , respectively, across the layer boundary.
At the boundary between the (L−1)th layer ( 125 .(L−1)) and the substrate layer ( 105 ), continuity of the electric field E y and the magnetic field H x requires
[ W L - 1 X L - 1 W L - 1 V L - 1 X L - 1 - V L - 1 ] [ c1 L - 1 c2 L - 1 ] = [ I jZ L ] T , ( 2.4 .3 )
where, as above, the top and bottom halves of the vector equation provides matching of the magnetic field H y and the electric field E x , respectively. In contrast with equation (2.4.1), there is only a single term on the right in equation (2.4.3) since there is no incident radiation in the substrate ( 105 ).
Matrix equation (2.4.1), matrix equation (2.4.3), and the (L−1) matrix equations (2.4.2) can be combined ( 460 ) to provide a boundary-matched system matrix equation
[ - I W 1 W 1 X 1 0 0 ⋯ jZ 0 V 1 - VX 0 0 ⋯ 0 - W 1 X 1 - W 1 W 2 W 2 X 2 0 0 ⋯ 0 - V 1 X 1 V 1 V 2 - V 2 X 2 0 0 ⋯ 0 0 ⋱ ⋱ ⋮ 0 0 - W L - 1 X L - 1 - W L - 1 I ⋯ - V L - 1 X L - 1 V L - 1 jZ L ]
[ R c1 1 c2 1 ⋮ ⋮ c1 L - 1 c2 L - 1 T ] = [ δ i0 j δ i0 cos ( θ ) / n 0 0 ⋮ ⋮ 0 ] , ( 2.4 .4 )
and the boundary-matched system matrix equation (2.4.4) may be solved ( 465 ) to provide the reflectivity R for each harmonic order i. (Alternatively, the partial-solution approach described in “Stable Implementation of the Rigorous Coupled-Wave Analysis for Surface-Relief Dielectric Gratings: Enhanced Transmittance Matrix Approach”, E. B. Grann and D. A. Pommet, J. Opt. Soc. Am. A , vol. 12, 1077-1086, May 1995, can be applied to calculate either the diffracted reflectivity R or the diffracted transmittance T.)
4. Solving for the Diffracted Reflectivity
The matrix on the left in boundary-matched system matrix equations (1.4.4) and (2.4.4) is a square non-Hermetian complex matrix which is sparse (i.e., most of its entries are zero), and is of constant block construction (i.e., it is an array of sub-matrices of uniform size). According to the preferred embodiment of the present invention, and as is well-known in the art of the solution of matrix equations, the matrix is stored using the constant block compressed sparse row data structure (BSR) method (see S. Carney, M. Heroux, G. Li, R. Pozo, K. Remington and K. Wu, “A Revised Proposal for a Sparse BLAS Toolkit,” http://www.netlib.org, 1996). In particular, for a matrix composed of a square array of square sub-matrices, the BSR method uses five descriptors:
B_LDA is the dimension of the array of sub-matrices; O is the dimension of the sub-matrices; VAL is a vector of the non-zero sub-matrices starting from the leftmost non-zero matrix in the top row (assuming that there is a non-zero matrix in the top row), and continuing on from left to right, and top to bottom, to the rightmost non-zero matrix in the bottom row (assuming that there is a non-zero matrix in the bottom row). COL_IND is a vector of the column indices of the sub-matrices in the VAL vector; and ROW_PTR is a vector of pointers to those sub-matrices in VAL which are the first non-zero sub-matrices in each row.
For example, for the left-hand matrix of equation (1.4.4), B_LDA has a value of 2L, O has a value of 2o+1, the entries of VAL are (−I, W 1 , W 1 X 1 , jY 0 , V 1 , −V 1 X 1 , −W 1 X 1 , −W 1 , W 2 , W 2 X 2 , −V 1 X 1 , V 1 , V 2 , . . . ), the entries of COL_IND are (1, 2, 3, 1, 2, 3, 2, 3, 4, 5, 2, 3, 4, 5, . . . ), and the entries of ROW_PTR are (1, 4, 7, 11, . . . ).
According to the preferred embodiment of the present invention, and as is well-known in the art of the solution of matrix equations, the squareness and sparseness of the left-hand matrices of equations (1.4.4) and (2.4.4) are used to advantage by solving equations (1.4.4) and (2.4.4) using the Blocked Gaussian Elimination (BGE) algorithm. The BGE algorithm is derived from the standard Gaussian Elimination algorithm (see, for example, Numerical Recipes, W. H. Press, B. P. Flannery, S. A. Teukolsky, and W. T. Vetterling, Cambridge University Press, Cambridge, 1986, pp. 29-38) by the substitution of sub-matrices for scalars. According to the Gaussian Elimination method, the left-hand matrix of equation (1.4.4) or (2.4.4) is decomposed into the product of a lower triangular matrix [L], and an upper triangular matrix [U], to provide an equation of the form
[L][U][x]=[b], (3.1.1)
and then the two triangular systems [U][x]=[y] and [L][y]=[b] are solved to obtain the solution [x]=[U] −1 [L] −1 [b], where, as per equations (1.4.4) and (2.4.4), [x] includes the diffracted reflectivity R.
5. Caching of Permittivity Harmonics and Eigensolutions
As presented above, the calculation of the diffraction of incident TE-polarized or TM-polarized incident radiation ( 131 ) from a periodic grating involves the generation of a boundary-matched system matrix equation (1.4.4) or (2.4.4), respectively, and its solution. In understanding the advantages of the present invention it is important to appreciate that the most computationally expensive portion of the processes of FIGS. 3 and 4 is the solution ( 347 ) and ( 447 ) for the eigenvectors w l,i and eigenvalues τ l,i of wave-vector matrix [A l ] of equation (1.3.7), (2.3.4), (2.3.5) or (2.3.6). The accuracy of the calculation of the eigenvectors w l,i and eigenvalues τ l,i is dependent on the number of orders o utilized. As the number of orders o is increased, the computation time for solving the eigensystem increases exponentially with o. When performed in a typical computing environment with o=9 harmonic orders, the calculation of the eigenvectors and eigenvalues can take more than 85% of the total computation time.
The method of the present invention is implemented on a computer system ( 800 ) which in its simplest form consists of information input/output (I/O) equipment ( 805 ), which is interfaced to a computer ( 810 ) which includes a central processing unit (CPU) ( 815 ) and a memory ( 820 ). The I/O equipment ( 805 ) will typically include a keyboard ( 802 ) and mouse ( 804 ) for the input of information, and a display ( 801 ) and printer ( 803 ) for the output of information. Many variations of this simple computer system ( 800 ) are to be considered within the scope of the present invention, including systems with multiple I/O devices, multiple processors within a single computer, multiple computers connected by Internet linkages, multiple computers connected by local area networks, devices that incorporate CPU ( 815 ), memory ( 820 ), and I/O equipment ( 805 ) into a single unit, etc. For instance, the method of the present invention may be applied to any of the systems described in provisional patent application Ser. No. 60/178,540, filed Jan. 26, 2000, entitled Profiler Business Model, by the present inventors, and provisional patent application Ser. No. 60/209,424, filed Jun. 2, 2000, entitled Profiler Business Model, by the present inventors, both of which are incorporated herein by reference.
According to the method and apparatus of the present invention, portions of the analysis of FIG. 3 are pre-computed and cached, thereby reducing the computation time required to calculate the diffracted reflectivity produced by a periodic grating. Briefly, the pre-computation and caching portion of the present invention consists of:
pre-computation and caching (i.e., storage in a look-up table) of the permittivity ε μ (x), the harmonic components ε μ,i of the permittivity ε μ (x) and the permittivity harmonics matrix [E μ ], and/or the inverse-permittivity harmonics π μ,i and the inverse-permittivity harmonics matrix [P μ ] for a sampling region {μ} of layer-property values; pre-computation and caching of the wave-vector matrix [A μ,κ ] for the sampling region {μ} of layer-property values and a sampling region {κ} of incident-radiation values; and pre-computation and caching of eigenvectors w μ,κ,m and eigenvalues τ μ,κ,m of the wave-vector matrix [A μ,κ ] to form an eigenvector matrix [W μ,κ ], a root-eigenvalue matrix [Q μ,κ ], and a compound matrix [V μ,κ ], respectively, for a master sampling region {μ, κ} formed from the combination of the layer-property sampling region {μ} and the incident-radiation sampling region {κ};
Briefly, the use of the master sampling region {μ, κ} of pre-computed and cached eigenvector matrices [W μ,κ ], root-eigenvalue matrices [Q μ,κ ], and product matrices [V μ,κ ] to calculate the diffraction spectrum from a periodic grating consists of the steps of:
construction of matrix equation (1.4.4) or (2.4.4) by retrieval of cached eigenvector matrices [W μ,κ ], root-eigenvalue matrices [Q μ,κ ] and product matrices [V μ,κ ] from the master sampling region {μ, κ} corresponding to the layers 125 of the grating ( 100 ) under consideration; and solution of the matrix equation (1.4.4) or (2.4.4) to determine the diffracted reflectivity R i for each harmonic order i.
The method of the present invention is illustrated by consideration of the exemplary ridge profiles ( 701 ) and ( 751 ) shown in cross-section in FIGS. 7A and 7B , respectively. The profile ( 701 ) of FIG. 7A is approximated by four slabs ( 711 ), ( 712 ), ( 713 ) and ( 714 ) of rectangular cross-section. Similarly, the profile ( 751 ) of FIG. 7B is approximated by three slabs ( 761 ), ( 762 ), and ( 763 ′) of rectangular cross-section. The two exemplary ridge profiles ( 701 ) and ( 751 ) are each part of an exemplary periodic grating (other ridges not shown) which have the same grating period D, angle θ of incidence of the radiation ( 131 ), and radiation wavelength λ. Furthermore, slabs ( 713 ) and ( 761 ) have the same ridge slab width d, x-offset β, and index of refraction n r , and the index of refraction n 0 of the atmospheric material between the ridges ( 701 ) and ( 751 ) is the same. Similarly, slabs ( 711 ) and ( 762 ) have the same ridge slab width d, x-offset β, and index of refraction n r , and slabs ( 714 ) and ( 763 ) have the same ridge slab width d, x-offset β, and index of refraction n r . However, it should be noted that slabs ( 714 ) and ( 763 ) do not have the same thicknesses t, nor do slabs ( 713 ) and ( 761 ) or slabs ( 711 ) and ( 762 ) have the same thicknesses t. It is important to note that thickness t is not a parameter upon which the wave-vector matrix [A] is dependent, although thickness t does describe an intra-layer property. It should also be noted that the present invention may be implemented with ridges mounted directly on a substrate, or ridges mounted on films deposited on a substrate, since a film can be considered to be a ridge having a width d equal to the pitch D.
In performing an RCWA calculation for the diffracted reflectivity from grating composed of profiles ( 701 ), the eigenvector matrices [W], the root-eigenvalue matrices [Q], and the compound eigensystem matrices [V] are computed for rectangular slabs ( 711 ), ( 712 ), ( 713 ), and ( 714 ). According to the present invention it is noted that the eigenvector matrices [W], the root-eigenvalue matrices [Q], and the compound eigensystem matrices [V] for slabs ( 761 ), ( 762 ) and ( 763 ) are the same as the eigenvector matrices [W], the root-eigenvalue matrices [Q], and the compound eigensystem matrices [V] for slabs ( 713 ), ( 711 ) and ( 714 ), respectively, since the wave-vector matrices [A] are the same for slabs ( 711 ) and ( 762 ), ( 713 ) and ( 761 ), and ( 714 ) and ( 763 ). Therefore, caching and retrieval of the eigensystem matrices [W], [Q], and [V] for slabs ( 713 ), ( 711 ) and ( 714 ) would prevent the need for recalculation of eigensystem matrices [W], [Q], and [V] for slabs ( 761 ), ( 762 ) and ( 763 ), and reduce the computation time. More broadly, the pre-calculation and caching of eigensystem matrices [W], [Q], and [V] for useful ranges and samplings of intra-layer parameters and incident-radiation parameters can reduce the computation time necessary to perform RCWA calculations.
As can be seen from equations (1.1.2), (1.1.3), (2.1.2) and (2.1.3), the permittivity harmonics ε l,i and the inverse permittivity harmonics π l,i are only dependent on the intra-layer parameters: the index of refraction of the ridges n r , the index of refraction of the atmospheric material n 0 , the pitch D, the ridge slab width d, and the x-offset β. As shown in the flowchart of FIG. 5 , in one exemplary embodiment, the system ( 600 ) of the present invention begins with the determination ( 605 ) of the ranges n r,min to n r,max , n 0,min to n 0,max , D min to D max , d min to d max , and β min to β max , and increments δn r , δn 0 , δD, δd, and δβ for the layer-property parameters, i.e., the index of refraction of the ridges n r , the index of refraction of the atmospheric material n 0 , the pitch D, the ridge slab width d, the x-offset β, as well as the determination ( 605 ) of the maximum harmonic order o.
This information is forwarded from an I/O device ( 805 ) to the CPU ( 815 ). Typically, when applied to periodic gratings produced by semiconductor fabrication techniques, the ranges n r,min to n r,max , n 0,min to n 0,max , D min to D max , d min to d max , and β min to β max are determined based on knowledge and expectations regarding the fabrication materials, the fabrication process parameters, and other measurements taken of the periodic grating ( 100 ) or related structures. Similarly, when matching calculated diffraction spectra to a measured diffraction spectrum to determine the dimensions of the periodic grating that created the measured diffraction spectrum, the increments δn r , δn 0 , δD, δd, and δβ, and maximum harmonic order o, are chosen based on the resolution to which the layer-property parameters n r , n 0 , D, d and β are to be determined. The layer-property parameter ranges n r,min to n r,max , n 0,min to n 0,max ; D min to D max , d min to d max , and β min to β max , and increments δn r , δn 0 , δD, and δd, and δβ define a five-dimensional layer-property caching grid {μ}. More specifically, the caching grid {μ} consists of layer-property points with the n r coordinates being {n r,min , n r,min +δn r , n r,min +2δn r , . . . , n r,max −2δn r , n r,max −δn r , n r,max }, the n 0 coordinates being {n min , n 0,min +δn 0 , n 0,min +2δn 0 , . . . , n 0,max −2δn 0 , n 0,max −δn 0 , n 0,max }, the D coordinates being {D min , D min +δD, D min +2δD, . . . , D max −2δD, D max −δD, D max }, the d coordinates being {d min , d min +δd, d min +2δd, . . . , d max −2δd, d max −δd, d max }, and the β coordinates being {β min , β min +δβ, β min +2δβ, . . . , β max −2δβ, β max −δβ, δ max }. In other words, the layer-property caching grid {μ} is defined as a union of five-dimensional coordinates as follows:
{ μ } = ⋃ i , j , k , l , m ( n r , min + ⅈ δ n r , n 0 , min + j δ n 0 , D min + k δ D , d min + l δ d , β min + m δβ ) ; ( 4.1 . )
where i, j, k, l and m are integers with value ranges of
0 ≦i ≦( n r,max −n r,min )/δ n r , (4.1.2a)
0 ≦j ≦( n 0,max −n 0,min )/δ n 0 , (4.1.2b)
0 ≦k ≦( D max −D min )/δ D, (4.1.2c)
0 ≦l ≦( d max −d min )/δ d, (4.1.2d)
and
0 ≦m ≦(β max −β min )/δβ. (4.1.2.e)
It should be noted that the variable l in equations (4.1.1) and (4.1.2d) is not to be confused with the layer number l used in many of the equations above. Furthermore, it may be noted that the layer subscript, l, is not used in describing the layer-property parameters n r , n 0 , D, d, and β used in the layer-property caching grid {μ} because each particular point μ j in the layer-property caching grid {μ} may correspond to none, one, more than one, or even all of the layers of a particular periodic grating ( 100 ). It should also be understood that the layer-property parameter region need not be a hyper-rectangle, and the layer-property parameter region need not be sampled using a grid. For instance, the sampling of the layer-property parameter region may be performed using a stochastic sampling method. Furthermore, the sampling density of the layer-property parameter region need not be uniform. For instance, the sampling density (i.e., the sampling resolution) may decrease near the boundaries of the layer-property parameter region if layers ( 125 ) described by layer properties near the boundaries are less likely to occur.
As shown in FIG. 5 , for each point μ j in the layer-property caching grid {μ} the “required” permittivity harmonics {overscore (ε i )} are calculated 410 by CPU ( 815 ) and cached ( 415 ) in memory ( 820 ), and the “required” permittivity harmonics matrices are compiled from the cached required permittivity harmonics {overscore (ε i )} and cached ( 415 ′) in memory ( 820 ). For RCWA analyses of TE-polarized incident radiation ( 131 ), or RCWA analyses of TM-polarized incident radiation ( 131 ) according to the formulation of equations (2.3.6) and (2.3.12), the required permittivity harmonics {overscore (ε i )} are the permittivity harmonics δ i calculated ( 410 ) according to equations (1.1.2) and (1.1.3), and the required permittivity harmonics matrix is the permittivity harmonics matrix [E] formed as per equation (1.1.4). Similarly, for RCWA analyses of TM-polarized incident radiation ( 131 ) according to the formulation of equations (2.3.5) and (2.3.11) or equations (2.3.4) and (2.3.10), the required permittivity harmonics {overscore (ε i )} are the permittivity harmonics ε l calculated ( 410 ) according to equations (1.1.2) and (1.1.3) and the inverse-permittivity harmonics π i calculated ( 410 ) according to equations (2.1.2) and (2.1.3), and the required permittivity harmonics matrices are the permittivity harmonics matrix [E] formed from the permittivity harmonics ε i as per equation (1.1.4) and the inverse-permittivity harmonics matrix [P] formed from the inverse-permittivity harmonics π i as per equation (2.1.4).
As per equations (1.3.7), (2.3.4), (2.3.5) and (2.3.6), the wave-vector matrix [A] is dependent on the required permittivity harmonics matrices and the matrix [K x ]. The matrix [K x ], in addition to being dependent on layer-property parameters (i.e., the atmospheric index of refraction no and pitch D), is dependent on incident-radiation parameters, i.e., the angle of incidence θ and the wavelength λ of the incident radiation ( 131 ). Therefore, as shown in the flowchart of FIG. 5 , according to one embodiment of the present invention, ranges θ min to θ max and λ min to λ max , and increments δθ and δλ are determined ( 617 ) for the incidence angle θ and wavelength λ, and forwarded from an I/O device ( 805 ) to the CPU ( 815 ). The incident-radiation caching grid {κ} is defined as a union of two-dimensional coordinates as follows:
{ κ } = ⋃ n , o ( θ min + n δ θ , λ min + o δλ ) ( 4.1 .3 )
where n and o are integers with value ranges of
0 ≦n ≦(θ max −θ min )/δθ, (4.1.4a)
0 ≦o ≦(λ max −λ min )/δλ. (4.1.4b)
(The variable o in equations (4.1.3) and (4.1.4b) is not to be confused with the maximum harmonic order o used in many of the equations above.) Furthermore, the master caching grid {μ, κ} is defined as a union of coordinates as follows:
{ μ , κ } = ⋃ i , j , k , l , m ( n r , min + ⅈ δ n r , n 0 , min + j δ n 0 , D min + k δ D , d min + l δ d , β min + m δβ , θ min + δθ , λ min + m δλ )
where i, j, k, l, m, n and o satisfy equations (4.1.2a), (4.1.2b), (4.1.2c), (4.1.2d), (4.1.4a) and (4.1.4b). Typically, the ranges θ min to θ max and λ min to λ max are determined ( 617 ) based on knowledge and expectations regarding the apparatus (not shown) for generation of the incident radiation ( 131 ) and the apparatus (not shown) for measurement of the diffracted radiation ( 132 ). Similarly, the increments δθ and δλ are determined ( 617 ) based on the resolution to which the layer-property parameters n r , n 0 , D, d, and β are to be determined, and/or the resolution to which the incident-radiation parameters θ and λ can be determined. For instance, the increments δn r , δn 0 , δD, δd, δβ, δθ, and δλ may be determined as per the method disclosed in the provisional patent application entitled Generation of a Library of Periodic Grating Diffraction Spectra, filed Sep. 15, 2000 by the same inventors, and incorporated herein by reference. For each point in the master caching grid {μ, κ}, the matrix [A] is calculated ( 620 ) by the CPU ( 815 ) according to equation (1.3.7), (2.3.4), (2.3.5) or (2.3.6) and cached ( 425 ).
It should be noted that if any of the layer-property parameters n r , n 0 , D, d, and β, or any of the incident-radiation parameters θ and λ, are known to sufficient accuracy, then a single value, rather than a range of values, of the variable may be used, and the dimensionality of the master caching grid {μ, κ} is effectively reduced. It should also be understood that incident-radiation parameter region need not be a hyper-rectangle, and the incident-radiation parameter region need not be sampled using a grid. For instance, the sampling of the incident-radiation parameter region may be performed using a stochastic sampling method. Furthermore, the sampling density of the incident-radiation parameter region need not be uniform. For instance, the sampling density may decrease near the boundaries of the the incident-radiation parameter region if radiation-incidence circumstances near the boundaries are less likely to occur.
Since the wave-matrix matrix [A] is only dependent on intra-layer parameters (index of refraction of the ridges n r , index of refraction of the atmospheric material n 0 , pitch D, ridge slab width d, x-offset β) and incident-radiation parameters (angle of incidence θ of the incident radiation ( 131 ), wavelength λ of the incident radiation ( 131 )), it follows that the eigenvector matrix [W] and the root-eigenvalue matrix [Q] are also only dependent on the layer-property parameters n r , n 0 , D, d, and β, and the incident-radiation parameters θ and λ. According to the preferred embodiment of the present invention, the eigenvector matrix [W] and its root-eigenvalue matrix [Q] are calculated ( 647 ) by the CPU ( 815 ) and cached ( 648 ) in memory ( 820 ) for each point in the master caching grid {μ, κ}. The calculation ( 647 ) of the eigenvector matrices [W] and the root-eigenvalue matrices [Q] can be performed by the CPU ( 815 ) using a standard eigensystem solution method, such as singular value decomposition (see Chapter 2 of Numerical Recipes , W. H. Press, B. P. Glannery, S. A. Teukolsky and W. T. Vetterling, Cambridge University Press, 1986). The matrix [V], where [V]=[W][Q], is then calculated ( 457 ) by the CPU ( 815 ) and cached ( 658 ) in memory ( 820 ).
The method of use of the pre-computed and cached eigenvector matrices [W μ,κ ], root-eigenvalue matrices [Q μ,κ ], and product matrices [V μ,κ ] according to the present embodiment of the invention is shown in FIG. 6 . Use of the cached eigensystem matrices [W μ,κ ], [Q μ,κ ], and [V μ,κ ] begins by a determination ( 505 ) of the parameters describing a discretized ridge profile. In particular, the intra-layer parameters (i.e., index of refraction of the ridges n r , the index of refraction of the atmospheric material n 0 , the pitch D, the ridge slab width d, and the x-offset β) for each layer, and the incident-radiation parameters (i.e., the angle of incidence θ and the wavelength λ of the incident radiation) are determined ( 505 ) and forwarded via an I/O device ( 805 ) to the CPU ( 815 ). The determination ( 505 ) of the discretized ridge profile may be a step in another process, such as a process for determining the ridge profile corresponding to a measured diffraction spectrum produced by a periodic grating.
Once the intra-layer and incident-radiation parameters are determined ( 505 ), the cached eigensystem matrices [W μ,κ ], [Q μ,κ ], and [V μ,κ ] for those intra-layer and incident-radiation parameters are retrieved ( 510 ) from memory ( 820 ) for use by the CPU ( 815 ) in constructing ( 515 ) the boundary-matched system matrix equation (1.4.4) or (2.4.4). The CPU ( 815 ) then solves ( 520 ) the boundary-matched system matrix equation (1.4.4) or (2.4.4) for the reflectivity R i of each harmonic order from −o to +o and each wavelength λ of interest, and forwards the results to an output device ( 805 ) such as the display ( 801 ), printer ( 803 ), or the like.
6. Library Matching Methodology
The reflected phase and magnitude signals obtained, in the case of ellipsometry, and relative reflectance, in the case of reflectometry, from the profile extraction metrology setup are then compared to the library of profile-spectra pairs generated by the cached-coupled wave algorithm. The matching algorithms that can be used for this purpose range from simple least squares approach (linear regression) to a neural network based approach that associates features of the signal with the profile through a non-linear relationship to a principal component based regression scheme. Explanations of each of these methods is explained in numerous excellent text books on these topics such as Chapter 14 of “Mathematical Statistics and Data Analysis” by John Rice, Duxbury Press and Chapter 4 of “Neural Networks for Pattern Recognition” by Christopher Bishop, Oxford University Press.
It should be noted that although the invention has been described in term of a method, as per FIGS. 5 and 6 , the invention may alternatively be viewed as an apparatus. For instance, the invention may implemented in hardware. In such case, the method flowchart of FIG. 5 would be adapted to the description of an apparatus by: replacement in step 605 of “Determination of ranges and increments of layer-property variables defining array {μ}, and means for determination of maximum harmonic order o” with “Means for determination of ranges and increments of layer-property variables defining array {μ}, and means for determination of maximum harmonic order o”; the replacement in step 617 of “Determination of incident-radiation ranges and increments defining array {κ}” with “Means for determination of incident-radiation ranges and increments defining array {κ}”; the replacement in steps 610 , 620 , 647 , and 657 of “Calculate . . . ” with “Means for Calculating . . . ”; and the replacement in steps 615 , 615 ′, 625 , 648 and 658 of “Cache . . . ” with “Cache of . . . ”.
In the same fashion, the method flowchart of FIG. 6 would be adapted to the description of an apparatus by: replacement of “Determination . . . ” in step 505 with “Means for determination . . . ”; replacement of “Retrieval . . . ” in step 510 with “Means for retrieval . . . ”; replacement of “Construction . . . ” in step 515 with “Means for construction . . . ”; and replacement of “Solution . . . ” in step 520 with “Means for solution . . . ”.
It should also be understood that the present invention is also applicable to off-axis or conical incident radiation 131 (i.e., the case where φ≠0 and the plane of incidence 140 is not aligned with the direction of periodicity, {circumflex over (x)}, of the grating). The above exposition is straightforwardly adapted to the off-axis case since, as can be seen in “Rigorous Coupled-Wave Analysis of Planar-Grating Diffraction,” M. G. Moharam and T. K. Gaylord, J. Opt. Soc. Am ., vol. 71, 811-818, July 1981, the differential equations for the electromagnetic fields in each layer have homogeneous solutions with coefficients and factors that are only dependent on intra-layer parameters and incident-radiation parameters. As with the case of on-axis incidence, intra-layer calculations are pre-calculated and cached. In computing the diffracted reflectivity from a periodic grating, cached calculation results for intra-layer parameters corresponding to the layers of the periodic grating, and incident-radiation parameters corresponding to the radiation incident on the periodic grating, are retrieved for use in constructing a boundary-matched system matrix equation in a manner analogous to that described above.
It is also important to understand that, although the present invention has been described in terms of its application to the rigorous coupled-wave method of calculating the diffraction of radiation, the method of the present invention may be applied to any diffraction calculation where the system is divided into layers, and where intermediate calculation results are only dependent on intra-layer variables. In such case the intermediate, intra-layer calculations may be pre-computed and cached. For instance, the diffraction calculation may be an approximate method, and/or it may use any of the formulations mentioned in the Background of the Invention section, such as integral formulations, or any other formulations, such as those mentioned in standard texts such as Solid State Physics, N. W. Ashcroft and N. D. Mermin, Saunders College, Philadelphia, 1976, pages 133-134, or Optical Properties of Thin Solid Films, O. S. Heavens, Dover Publications, Inc., New York, 1991, or Ellipsometry and Polarized Light, R. M. A. Azzam and N. M. Bashara, North-Holland Personal Library, Amsterdam, 1987. Furthermore, the present invention may be applied to diffraction calculations based on decompositions or analyses other than Fourier analysis, such as a decomposition into Bessel functions, Legendre polynomials, wavelets, etc. More generally, the method of the present invention may be applied to any diffraction calculation where the system is divided into sections, and where intermediate calculation results are only dependent on intra-section variables. Again, the intermediate, intra-section calculations may be pre-computed and cached. For instance, for a two-dimensionally periodic structure, the sections may be a regular array of blocks or cubes. Still more generally, the method of the present invention may be applied to any calculation where the system is divided into sections, and where intermediate calculation results are only dependent on intra-sections variables. Again, the intermediate, intra-section calculations may be pre-computed and cached.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and it should be understood that many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. Many other variations are also to be considered within the scope of the present invention. For instance: the calculation of the present specification is applicable to circumstances involving conductive materials, or non-conductive materials, or both, and the application of the method of the present invention to periodic gratings which include conductive materials is considered to be within the scope of the present invention; once the eigenvectors and eigenvalues of a wave-vector matrix [A] are calculated and cached, intermediate results, such as the permittivity, inverse permittivity, permittivity harmonics, inverse-permittivity harmonics, permittivity harmonics matrix, the inverse-permittivity harmonics matrix, and/or the wave-vector matrix [A] need not be stored; the compound matrix [V], which is equal to the product of the eigenvector matrix and the root-eigenvalue matrix, may be calculated when it is needed, rather than cached; the eigenvectors and eigenvalues of the matrix [A] may be calculated using another technique; a range of an intra-layer parameter or an incident-radiation parameter may consist of only a single value; the grid of regularly-spaced layer-property values and/or incident-radiation values for which the matrices, eigenvalues and eigenvectors are cached may be replaced with a grid of irregularly-spaced layer-property values and/or incident-radiation values, or a random selection of layer-property values and/or incident-radiation values; the boundary-matched system equation may be solved for the diffracted reflectivity and/or the diffracted transmittance using any of a variety of matrix solution techniques; the “ridges” and “troughs” of the periodic grating may be ill-defined; a one-dimensionally periodic structure in a layer may include more than two materials; the method of the present invention may be applied to gratings having two-dimensional periodicity; a two-dimensionally periodic structure in a layer may include more than two materials; the method of the present invention may be applied to any polarization which is a superposition of TE and TM polarizations; the ridged structure of the periodic grating may be mounted on one or more layers of films deposited on the substrate; the method of the present invention may be used for diffractive analysis of lithographic masks or reticles; the method of the present invention may be applied to sound incident on a periodic grating; the method of the present invention may be applied to medical imaging techniques using incident sound or electromagnetic waves; the method of the present invention may be applied to assist in real-time tracking of fabrication processes; the gratings may be made by ruling, blazing or etching; the grating may be periodic on a curved surface, such as a spherical surface or a cylindrical surface, in which case expansions other than Fourier expansions would be used; the method of the present invention may be utilized in the field of optical analog computing, volume holographic gratings, holographic neural networks, holographic data storage, holographic lithography, Zernike's phase contrast method of observation of phase changes, the Schlieren method of observation of phase changes, the central dark-background method of observation, spatial light modulators, acousto-optic cells, etc. In summary, it is intended that the scope of the present invention be defined by the claims appended hereto and their equivalents.
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A library of simulated-diffraction signals for an integrated circuit periodic grating is generated by generating sets of intermediate layer data. Each set of intermediate layer data corresponding to a separate one of a plurality of hypothetical layers of a hypothetical profile of the periodic grating. Each separate hypothetical layer has one of a plurality of possible combinations of hypothetical values of properties for that hypothetical layer. The generated sets of intermediate layer data are stored. Simulated-diffraction signals for each of a plurality of hypothetical profiles are generated based on the stored generated sets of intermediate layer data.
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[0001] This patent application claims priority from U.S. Provisional Patent Application No. 61/325,204, entitled “Metformin-Cysteine Prodrug”, filed Apr. 16, 2010, (Docket No. COD5262USPSP), the specification of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] “A consensus statement from the American Diabetes Association and the European Association for the Study of Diabetes recommends metformin therapy as first-line therapy along with lifestyle modification to treat type 2 diabetes mellitus.” Philbrick, Am. J. Health Syst. Pharm., 2009 Nov. 15; 66 (22):2017-23. According to Wikipedia, metformin was introduced to the United Kingdom in 1958, Canada in 1972, and the United States in 1995. Metformin is now believed to be the most widely prescribed anti-diabetic drug in the world. In the United States alone, more than 40 million prescriptions were filled in 2008 for its generic formulations. Because of metformin's status as a first line diabetic therapy, Bristol-Myers Squibb's diabetic drug Glucophage® brought in peak sales of $1.7 billion before its patent expired in 2000.
[0003] Metformin is a synthetic biguanadine having a molecular weight of about 165. Its molecular structure is shown in FIG. 1 a.
[0004] It is believed that metformin improves glucose control in diabetics by increasing AMPK in hepatocytes, thereby providing control over glucose production.
[0005] Despite the effectiveness of metformin as a diabetes medication, it nonetheless suffers from some drawbacks. In particular, Marathe, Br. J. Clin., Pharmacol., 50, 325-332 (2000) has reported that, while metformin is effectively taken up in the small intestine, it is poorly absorbed in the colon. As a result, the time window for effective plasma concentrations of metformin is limited to about 6 hours. See, for example, FIG. 4 of US Patent Publication 2007-0154548 (Cheng Xiu), which reports that the window in which metformin is above ½ of its Cmax is only about 6 hours. Because of this narrow absorption window, metformin is typically presecribed to be taken about 2-3 times a day.
[0006] A number of attempts at improving the bioavailability of metformin involve providing metformin in an extended release dosage form that releases metformin in the colon. See, for example, US Patent Publication 2007275061; US Patent Publication 2007264331; and US Patent Publication 2009124702. However, these efforts to not improve the uptake efficiency of metformin in the colon.
[0007] Other attempts at improving the bioavailability of metformin involve providing metformin salts of lipophilic acids. See, for example, US Patent Publication 2003-0220301 (Lal).
[0008] US Patent Publication 2005-0158374 (Wong) discloses a complex comprised of metformin and a transport moiety, such as a fatty acid, is described. Wong reports that this complex has an enhanced absorption in the gastrointestinal tract, particularly the lower gastrointestinal tract. The complex, and compositions and dosage forms prepared using the complex, provide for absorption by the body of the drug through a period of ten to twenty-four hours, thus enabling a once-daily dosage form for metformin.
[0009] Other attempts have been made to improve the bioavailability of metformin by delivering it as a more lipophilic prodrug. In particular, the investigators in Huttunen, J. Med. Chem., 2009, 52, 14, 4142-4148 noted that N—S bonds may be cleaved by endogenous thiols and created sulfonamide prodrugs of metformin ( FIG. 1 c ). The investigators report that the enhanced lipophilicity of these prodrugs appear to allow their passive diffusion into intestinal cells and that the metformin bioavailability increased from about 43% to about 60%.
SUMMARY OF THE INVENTION
[0010] It is noted that certain amino acids such as cysteine and NAC share a commonality with the Huttunen prodrugs in that each has a HS sulfur moeity. Accordingly, it is believed that a prodrug comprising metformin and cysteine may be made in a manner substantially similar to the Huttunen prodrugs, that is by achieving a N—S bond that includes the nitrogen of the NH 2 group in metformin and the sulfur of cysteine. This novel prodrug of the present invention is shown in FIG. 2 .
[0011] In addition, while not wishing to be tied to a theory, it is believed that the resulting prodrug will have an improved intestinal uptake, superior even to the Huttunen prodrugs. In particular, it is noted that the prodrug of the present invention will possess an amino-cysteine moiety. It is further noted that s-nitroso-L-cysteine also possesses an amino-cysteine moiety, and that both Li, J. Biol. Chem., 280, 20, 20102-10 and Namoto, Eur. J. Pharmacol., 2003, Jan. 1, 458(1-2):17-24 report that s-nitroso-L-cysteine is efficiently transported by the LAT1 and LAT2 transporters. Therefore, it is reasonable to conclude that the amino-cysteine moiety of the prodrug of the present invention will allow for its transport in the LAT1 and LAT2 transporter system. Because the LAT1 and LAT2 transporters are important and effective transporters of amino acids in both the small intestine and colon, it is believed that the LAT-transportable prodrugs of the present invention will be effectively absorbed both in small intestine and in the colon. The increased absorption window provided by the present invention should result in highly sustained plasma concentrations of metformin, thereby increasing the effectiveness of the medication and allowing for a single daily dose.
[0012] Of note, Wang, J. Nutr., Biochem., 2002 October; 13(10):625-633 reported that dietary supplementation of cysteine prodrugs to PM mice restored GSH levels in liver, lung, heart and spleen, but not in colon. Therefore, in that neither metformin nor cysteine appear to be taken up by the colon, it is indeed surprising that a prodrug comprising metformin and cysteine can be taken up by the colon.
[0013] Therefore, in accordance with the present invention, there is provided a metformin-cysteine prodrug.
[0014] In some embodiments, the metformin-cysteine prodrug comprises (Hybrid I):
[0000]
[0015] In some embodiments, the metformin-cysteine prodrug comprises (Hybrid II):
[0000]
DESCRIPTION OF THE FIGURES
[0016] FIG. 1 a provides the molecular structure of metformin.
[0017] FIG. 1 b provides the molecular structure of cysteine.
[0018] FIG. 1 c provides the molecular structure of n-acetylcysteine (NAC).
[0019] FIGS. 2 a and 2 b provide the molecular structures of two molecules of the present invention, Hybrids I and II, respectively.
[0020] FIGS. 3 and 4 disclose methods of making the present invention in accordance with the Guarino approach.
DETAILED DESCRIPTION OF THE INVENTION
[0021] In addition to the increased bioavailability of the metformin-cysteine prodrug of the present invention, it is further noted that the cysteinic portion of the prodrug may also provide benefit to the diabetic patient.
[0022] First, it is believed that the cysteine portion of the prodrug forms a disulfide with GSH to produce Cy-LLGSH. This molecule has been characterized as a prodrug that is cleaved back into cysteine and GSH moieties. See Cacciatoreo, Molecules, 2010, pp 1242-1264.
[0023] Second, it has been widely reported in the literature that cysteine is regarded as the rate-limiting building block for the tripeptide glutathione (GSH). Dilger, J. Anim. Sci. 2007, 85:1712-18. Since GSH is well known as one of the most potent endogenous antioxidants, it is believed that the cysteine portion of the prodrug will help ameliorate reactive oxygen species in type II diabetes.
[0024] Third, there have been several clinical trials assessing the efficacy of NAC for type II diabetic patients. See, for example, NCT00556465; Masha, J. Endocrinol. Invest., 2009 April:32(4) 352-6; and Saklayan, J Investig Med., 2010 January; 58(1):28-31.
[0025] Fourth, the Cy-LLGSH prodrug produced by metabolism of the novel prodrug has been shown to be “highly effective” in protecting mice against acetaminophen-induced hepatotoxicity. The authors credit the success of the treatment to an enzymatic process that provides glutathione directly to the cells. Berkeley, J. Biochem. Molec. Toxicology, 17, 2, 2003, 95-97
[0026] Finally, de Oliveira, Hepatology Research, 2008, 38, 159-165 reports that the combination of metformin and NAC provided the significant amelioration of the complications of non-alcoholic fatty liver disease in human patients. de Oliveira further reports that neither metformin nor NAC alone provided any significant benefits to NASH patients.
[0027] In order to make the novel molecules of the present invention, standard organic chemistry techniques for sulfenamide synthesis may be used. In one approach, the techniques of sulfenamide synthesis disclosed in Scheme 2 of Guarino, Bioorg . & Medicinal Chemistry Letters 17, (2007) 4910-13 are used. Prophetic examples of the Guarino approach are provided in FIGS. 3 a and 3 b . Barton, J. Org. Chem., 56, 23, 1991 6702-4 teaches that methods of sulfonamide synthesis such as Guarino's that react chlorothiols with amides can reliably form sulfenamides provided that the reaction is carried out under high pH and with the use of a nonpolar aprotic solvent (such as THF).
Exemplary Dosage Forms and Methods of Use
[0028] It is believed that the novel molecules described above provide an enhanced absorption rate in the G.I. tract, and in particular in the lower G.I. tract. Dosage forms and methods of treatment using these molecules and their increased colonic absorption will now be described. It will be appreciated that the dosage forms described below are merely exemplary.
[0029] A variety of dosage forms are suitable for use with the metformin-cysteine hybrid. As discussed above, a dosage form that provides once daily dosing to achieve a therapeutic efficacy for at least about 15 hours, more preferably for at least 18 hours, and still more preferably for at least about 20 hours, is desired. The dosage form may be configured and formulated according to any design that delivers a desired dose of metformin. Typically, the dosage form is orally administrable and is sized and shaped as a conventional tablet or capsule. Orally administrable dosage forms may be manufactured according to one of various different approaches. For example, the dosage form may be manufactured as a diffusion system, such as a reservoir device or matrix device, a dissolution system, such as encapsulated dissolution systems (including, for example, “tiny time pills”, and beads) and matrix dissolution systems, and combination diffusion/dissolution systems and ion-exchange resin systems.
[0030] The dose administered is generally adjusted in accord with the age, weight, and condition of the patient, taking into consideration the dosage form and the desired result. In general, the dosage forms and compositions of the metformin-cysteine hybrid are administered in amounts recommended for metformin HCl (Glucophage®, Bristol-Myers Squibb Co.) as set forth in the Physician's Desk Reference. For example, oral dosage of metformin HCl is individualized on the basis of effectiveness and tolerance, while not exceeding the maximum daily recommended dose of 2550 mg in adults and 2000 mg in pediatric patients. Metformin HCl is typically administered in divided doses with meals and is often initiated at a low dose, typically of about 850 mg/day, with gradual escalation to permit identification of a minimum therapeutically effective amount required for an individual's anti-hyperglycemic activity. Thus, in one embodiment, a dosage form that provides a daily metformin dose of between 500-2550 mg is provided, where the metformin is provided in the form of a metformin-cysteine hybrid.
[0031] In another aspect, the invention contemplates administering a metformin-cysteine hybrid in combination with a second therapeutic agent, for treatment of hyperglycemia and for management of weight, particularly in Type II diabetic subjects. Preferred second therapeutic agents are those useful in the treatment of obesity, diabetes mellitus, especially Type II diabetes, and conditions associated with diabetes mellitus.
[0032] Exemplary second therapeutic agents include, but are not limited to, compounds classified as an alpha glucosidase inhibitor, a biguanide (other than metformin), an insulin secretagogue, an antidiabetic agent, or an insulin sensitizer. Exemplary alpha glucosidase inhibitors include acarbose, emiglitate, miglitol, voglibose. A suitable antidiabetic agent is insulin. Biguanides include buformin and phenformin. Suitable insulin secretagogues include sulphonylureas, such as glibenclamie, glipizide, gliclazide, glimepiride, tolazamide, tolbutamine, acetohexamide, carbutamide, chlorpropamide, glibornuride, gliquidone, glisentide, glisolamide, glisoxepide, glyclopyamide, repaglinide, nateglinide, and glycyclamide. Insulin sensitizers include PPAR-gamma agonist insulin sensitizers (see WO97/31907), such as 2-(1-carboxy-2-{4-2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-phenyl-ethyla-mino)-benzoic acid methyl ester and 2(S)-(2-benzoyl-phenylamino)-3-4-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-phenyl}-propionic acid.
[0033] The second therapeutic agent is preferably an anti-diabetic compound, such as insulin signaling pathway modulators, like inhibitors of protein tyrosine phosphatases (PTPases), non-small molecule mimetic compounds and inhibitors of glutamine-fructose-6-phosphate amidotransferase (G FAT), compounds influencing a dysregulated hepatic glucose production, like inhibitors of glucose-6-phosphatase (G6Pase), inhibitors of fructose-1,6-bisphosphatase (F-1,6-BPase), inhibitors of glycogen phosphorylase (GP), glucagon receptor antagonists and inhibitors of phosphoenolpyruvate carboxykinase (PEPCK), pyruvate dehydrogenase kinase (PDHK) inhibitors, insulin sensitivity enhancers, insulin secretion enhancers, .alpha.-glucosidase inhibitors, inhibitors of gastric emptying, insulin, and .alpha.sub.2-adrenergic antagonists, or the pharmaceutically acceptable salts of such a compound and optionally at least one pharmaceutically acceptable carrier; for simultaneous, separate or sequential use, particularly in the prevention, delay of progression or treatment of conditions mediated by DPP-IV, in particular conditions of impaired glucose tolerance (IGT), conditions of impaired fasting plasma glucose, metabolic acidosis, ketosis, arthritis, obesity and osteoporosis, and preferably diabetes, especially type 2 diabetes mellitus. Such a combination is preferably a combined preparation or a pharmaceutical composition.
[0034] In a combined treatment method, the metformin-cysteine hybrid and the second therapeutic agent are administered simultaneously or sequentially, by the same or different routes of administration.
[0035] In a preferred embodiment, the second therapeutic agent is a dipeptidyl peptidase IV (DPP-IV) inhibitor. Dipeptidyl peptidase IV is a post-proline/alanine cleaving serine protease found in various tissues in the body, including kidney, liver, and intestine. The protease removes the two N-terminal amino acids from proteins having proline or alanine in the position 2. DPP-IV can be used in the control of glucose metabolism because its substrates include the insulinotropic hormones glucagons like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP). GLP-1 and GIP are active only in their intact forms; removal of their two N-terminal amino acids inactivates them (Holst, J. et al., Diabetes, 47:1663 (1998)).
[0036] Thus, inhibitors of DPP-IV have been described, for example, in U.S. Pat. Nos. 6,124,305; 6,107,317; and in PCT Publication Nos. WO99/61431; WO98/19998; WO95/15309; WO98/18736. The inhibitors can be peptidic or non-peptidic, such as 1 [2-(5-cyanopyridin-2yl)aminoethylamino-]acetyl-2-cyano-(S)-pyrrolidine and (2S)-1-[(2S)-2-amino-3,3-dimethylbutan-oyl]-2-pyrrolidinecarbonitrile.
[0037] A method for treating a subject having Type II diabetes is contemplated, where the subject is treated with a DPP-IV inhibitor in combination with a metformin-cysteine hybrid. The combined agents produces a greater beneficial effect than achieved for either agent alone or for a combination of a DPP-IV inhibitor and metformin. The metformin-cysteine hybrid is preferably administered orally in a once-daily dosage form, to take full advantage of the enhanced colonic absorption provided by the hybrid. The DPP-IV inhibitor can be administered by any route suitable for the compound and the patient.
[0038] In one embodiment, the combined treatment regimen is for use in reducing or preventing body weight gain in overweight or obese patients with Type II diabetes. It has been recently shown that a combination therapy of metformin with DPP-IV inhibitor leads to reduced food intake and body weight gain in Zucker fa/fa rats (Yasuda, N. et al., J. Pharmacol. Experimental Therap., 310(2):614 (2004)). The invention provides an improved combination regimen by administering metformin as a metformin-cysteine hybrid to achieve an enhanced colonic absorption.
[0039] An effective dosage is defined in the present invention as the amount of a compound that prevents or ameliorates adverse conditions or symptoms of disease(s) or disorder(s) being treated. The amount to be administered to a patient and the frequency of administration to the subject can be readily determined by one of ordinary skill in the art by the use of known techniques and by observing results obtained under analogous circumstances. In determining the effective dosage, a number of factors are considered by the attending diagnostician, including but not limited to, the potency and duration of action of the compounds used; the nature and severity of the illness to be treated as well as the sex, age weight, general health and individual responsiveness of the patient to be treated, and other relevant circumstances.
[0040] The compositions of the invention are preferably administered enterally or parenterally (parenteral administration includes subcutaneous, intramuscular, intradermal, intramammary, intravenous, and other administrative methods known in the art), or better still orally, although other routes of administration, for instance such as rectal administration, are not excluded.
[0041] For preparing oral pharmaceutical compositions from the compounds of this invention, inert, pharmaceutically acceptable carriers can be either solid or liquid. Solid form preparations include powders, tablets, coated tablets, dragees, troches, lozenges, dispersible granules, capsules, and sachets. Compositions for oral use may be prepared according to any method known in the art of manufacture of pharmaceutical compositions.
[0042] A solid carrier can be one or more substances which may also act as diluents, flavoring agents, solubilizers, lubricants, suspending agents, binders, or tablet disintegrating agents. It can also be an encapsulating material. In powders, the carrier is a finely divided solid, which is in admixture with the finely divided active component. In tablets, the active compound is mixed with the carrier having the necessary binding properties in suitable proportions and compacted in the shape and size desired. Suitable carriers include, for example, inert diluents, such as magnesium carbonate, calcium stearate, magnesium stearate, talc, lactose, sugar, pectin, dextrin, starch, tragacanth, methyl cellulose, sodium carboxymethyl cellulose, and the like.
[0043] The present invention also includes the formulation of metformin-cysteine hybrid and orlistat with encapsulating material as a carrier providing a capsule in which the hybrid and orlistat (with or without other carriers) are surrounded by a carrier, which is thus in association with the hybrid and orlistat. In a similar manner, sachets are also included. Tablets, powders, sachets, and capsules can be used as solid dosage forms suitable for oral administration.
[0044] The tablets may be uncoated or coated by known techniques to delay disintegration and adsorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed.
[0045] Formulations for oral use may also be presented as hard gelatin capsules in which the active compounds are mixed with inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules in which the active compounds are present as such, or mixed with water or an oil medium, for example, arachid oil, liquid paraffin, or olive oil.
[0046] Aqueous suspensions can be produced that contain the active compounds in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients include suspending agents, such as sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, sodium alginate, polyvinylpyrrolidone gum tragacanth and gum acacia; dispersing or wetting agents e.g. naturally-occurring phosphatides, such as lecithin, condensation products of an alkylene oxide with fatty acids, such as polyoxyethylene stearate, condensation products of an alkylene oxide with fatty acids, such as polyoxyethylene stearate, condensation products of ethylene oxide with long chain aliphatic alcohols, such as heptadecaethyleneoxycetanol, condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol, such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, such as polyoxyethylene sorbitan monooleate.
[0047] The aqueous suspensions may also contain one or more preservatives, for example, ethyl or n-propyl p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, one or more sweetening agents.
[0048] Oily suspensions may be formulated by suspending the active compounds in an omega-3 fatty acid, a vegetable oil, for example arachid oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example, beeswax, hard paraffin or cetyl alcohol.
[0049] Sweetening agents and flavoring agents may be added to provide a palatable oral preparation, which may be preserved by the addition of an antioxidant such as ascorbic acid.
[0050] Dispersible powders and granules suitable for the preparation of an aqueous suspension by the addition of water provide the active compounds in admixture with a dispersing or wetting agent, a suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavoring and coloring agents, may also be present.
[0051] Syrups and elixirs containing the novel combination may be formulated with sweetening agents. Such formulations may also contain a demulcent, a preservative and flavoring and coloring agents.
[0052] Liquid form preparations include solutions, suspensions and emulsions suitable for oral administration. Aqueous solutions for oral administration can be prepared by dissolving the active compounds in water and adding suitable flavoring agents, coloring agents, stabilizers, and thickening agents as desired. Ethanol, propylene glycol and other pharmaceutically acceptable non-aqueous solvents may be added to improve the solubility of the active compounds. Aqueous suspensions for oral use can be made by dispersing the finely divided active compounds in water together with a viscous material such as natural or synthetic gums, resins, methyl cellulose, sodium carboxymethyl cellulose, and other suspending agents known in the pharmaceutical formulation art.
[0053] Preferably, the pharmaceutical composition is in unit dosage form. In such form, the preparation is divided into unit doses containing appropriate amounts of the active compounds. The unit dosage form can be a packaged preparation, the package containing discrete amounts of the preparation, for example, packeted tablets, capsules, and powders in vials or ampoules. The unit dosage form can also be a capsule, cachet, or tablet itself, or it can be the appropriate number of any of these packaged forms.
[0054] Formulations developed for the metformin-cysteine hybrid can be used for the pharmaceutical composition of the invention containing the hybrid and orlistat. Such formulations are described in the following patents: gastric retentive (U.S. Pat. No. 6,340,475=WO 9855107 and U.S. Pat. No. 6,120,803=WO 9907342), controlled-release metformin composition (U.S. Pat. No. 6,790,459=WO 0236100), controlled-release with unitary core (U.S. Pat. No. 6,099,859=WO 9947125), treatment with 400 mg or below of metformin (U.S. Pat. No. 6,100,300), novel salts of metformin (U.S. Pat. No. 6,031,004=WO 9929314), biphasic controlled-release delivery system (U.S. Pat. No. 6,475,521=WO 9947128), metformin preparation (U.S. Pat. No. 5,955,106=WO 9608243), controlled-release (WO 0103964 and US 2004/175424=WO 0239984), metformin tablet (US 2003/021841=WO 03004009), sustained-release composition (US 2002/132002=WO 02067905), controlled-release composition (U.S. Pat. No. 6,491,950=WO 0211701), gastroretentive (WO 0006129), solid carriers for improved delivery (U.S. Pat. No. 6,923,988=WO 0137808), coating for sustained-release composition (U.S. Pat. No. 6,946,146=WO 02085335), modified-release composition (US 2004/213844=WO 03002151), liquid formulation of metformin (WO 0247607), controlled-release device (U.S. Pat. No. 6,960,357=WO 02094227), metformin quick release tablet (JP 2002326927). Among these formulations, the metformin once a day formulation is preferred.
[0055] The compositions of the invention can also be administered parenterally either subcutaneously, or intravenously, or intramuscularly, or intrasternally, or by infusion techniques, in the form of sterile injectable aqueous or olagenous suspensions. Such suspensions may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above, or other acceptable agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvent that may be employed, water, Ringer's solution and isotonic sodium chloride solution may be mentioned. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, n-3 polyunsaturated fatty acids may find use in the preparation of injectables.
[0056] The compositions of the invention can also be administered by inhalation, in the form of aerosols or solutions for nebulizers, or rectally in the form of suppositories prepared by mixing the drug with a suitable non irritating excipient, which is solid at ordinary ambient temperature but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such materials include cocoa butter and polyethylene glycols.
[0057] Preferably, the composition is a controlled-release composition.
[0058] Daily dosages can vary within wide limits and will be adjusted to the individual requirements in each particular case. In general, for administration to adults, an appropriate daily dosage has been described above, although the limits that were identified as being preferred may be exceeded if expedient. The daily dosage can be administered as a single or divided dose.
[0059] The amount of each compound to be administered will depend on a number of factors including the age of the patient, the severity of the condition and the past medical history of the patient. Each unit dose generally contains (1) from about 100 to 1000 mg of metformin and/or (2) from about 50 to about 720 mg, preferably about 120 to about 360 mg, of orlistat. Typical unit doses preferably contain 500 mg, 850 mg or 1000 mg of metformin (850 mg being especially preferred) and/or 120 mg of orlistat. It will however be appreciated that formulations containing doses of metformin and/or orlistat which are bioequivalent to the preferred doses mentioned above, are within the scope of the invention. For example, a formulation containing a dose of metformin which is bioequivalent to the dose of the Glucophage® 850 formulation, is contemplated.
[0060] When the pharmaceutical composition comprises a fibrate, each unit dose generally contains from about 10 to about 1000 mg, preferably about 50 to 600 mg, more preferably about 50 to about 200 mg, of fibrate. When the pharmaceutical composition comprises a statin, each unit dose generally contains from about 0.1 to 100 mg of statin, e.g. 0.1, 0.3, 0.8, 1, 2, 5, 10, 20, 40 or 80 mg of statin.
[0061] The present invention further relates to kits that are suitable for use in performing the methods of treatment described above. In one embodiment, the kit contains (i) one or more unit doses of the hybrid, (ii) one or more unit doses of orlistat, (iii) optionally one or more unit doses of a fibrate, and (iv) optionally one or more unit doses of a statin, for a simultaneous or sequential administration, in amounts sufficient to carry out the methods of the present invention.
[0062] In some embodiments, the molecule of the present invention can be used for treating a patient having Alzheimer's Disease or mild cognitive impairment (MCI). Both metformin (Kickstein, Proc Natl Acad Sci USA, 2010 Dec. 14; 107(50):21830-5) and NAC (McCaddon, CNS Spectr. 2010 January; 15(1 Suppl 1):2-5;) have been discussed as potential treatment for Alzheimer's Disease.
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A metformin-cysteine prodrug. It is believed that the prodrug of the present invention will transport in the LAT1 and LAT2 transporter system. Because the LAT1 and LAT2 transporters are important and effective transporters of amino acids in both the small intestine and colon, it is believed that the LAT-transportable prodrugs of the present invention will be effectively absorbed both in small intestine and in the colon. The increased absorption window provided by the present invention should result in highly sustained plasma concentrations of metformin, thereby increasing the effectiveness of the medication and allowing for a single daily dose.
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FIELD OF THE INVENTION AND RELATED ART STATEMENT
[0001] 1. Field of the Invention
[0002] The present invention relates to a universal guide device that is used in sliding portions of various machine tools, part-conveying systems, and so on and is capable of guiding a movable object or material over a conveyance path containing both straight and curved regions.
[0003] 2. Related Art
[0004] For example, on a product line or the like in a plant, if all processing stations are arranged linearly, then no problems will take place. However, depending on the space of the plant in which a machine is installed or on the contents of the processing performed in processing stations, it may be necessary to change the direction of conveyance of materials to be processed between two adjacent processing stations. In this case, it is customary to use a pallet changer or the like to achieve a change in the direction of conveyance. Unfortunately, additional space and cost for installing the pallet changer or the like are necessary.
[0005] Known means for modifying the direction of conveyance of materials or objects without using a pallet changer include universal guide devices (as described in Laid-open, unexamined Japanese patent application Nos. 293319/1988 and 50333/1994) capable of guiding materials continuously along a path including both straight and curved lines and curved guide devices (as described in Laid-open, unexamined Japanese patent application No. 186028/1988) capable of guiding materials continuously along an annular path.
[0006] These universal guide devices and curved guide devices each comprise a track rail, a slider, and a number of balls. The rail forms longitudinally extending surfaces on which the balls roll. The slider is mounted to span the rail. Load-rolling surfaces opposite to the rolling surfaces of the rail and an endless circular path for the balls are formed on and in the slider. The endless circular path includes the load-rolling surfaces. The balls roll in the endless circular path of the slider and between the rolling surfaces of the rail and the load-rolling surfaces of the slider carry a load. The slider moves along the rail in response to rolling movement of the balls.
[0007] In the former universal guide device, each load-rolling surface of the slider is partitioned into straight load regions formed linearly and curved load regions shaped into an arc in conformity with the curvature of the rail. In each straight load region of the rail, the load acting on the slider is carried by the balls rolling in the straight load region. In each curved region, the load is carried by the balls rolling in the curved region. As a result, even if straight and curved regions are intermingled on the track rail, the slider can move along the rail through the straight and curved regions continuously.
[0008] In the latter curved guide device, the track rail is shaped into an arc having a given curvature. The load-rolling surface of the slider is shaped into an arc in conformity with the curvature of the rail. All the balls interposed between the load-rolling surface of the slider and the rolling surface of the rail roll on while carrying the load acting on the slider. In consequence, the slider can make a curved motion along the rail.
[0009] In these conventional universal guide devices and curved guide devices, the load-rolling groove or race in the slider is shaped into an arc in conformity with the curvature of the track rail to permit movement of the slider through the curved region of the rail. Therefore, it has been necessary to machine the load-rolling surface in conformity with the curvature of the rail. Consequently, it has been impossible to directly use the sliders of conventional mass-produced linear guide devices that are available in the market. Hence, the production cost is increased. Furthermore, a different slider is necessary for each different curvature of track rail. Therefore, it is laborious to machine the sliders and to manage finished products.
[0010] Where the load-rolling surface of a slider is machined into an arc, the direction of bending of the curved region of a track rail is limited to one direction, left or right. Although it is possible to transport materials and objects annularly, it is impossible to convey materials along a track including two curved regions bent in different directions such as an S-shaped track.
[0011] On the other hand, in a path between two adjacent machining stations on a product line, if materials can be transported, no problems take place. It is considered that capability to carry very large loads is not necessary in curved regions of the rail. However, during a machining process, a machining force acting on a material needs to be sustained reliably by a guide device. Straight regions of the rail are required to have ability to carry a larger load than curved regions. In the aforementioned conventional universal guide device, the load-rolling surface formed on the slider is divided into straight and curved load regions. Therefore, the straight regions of the rail have decreased ability to sustain loads. Consequently, a machining force acting on materials cannot be sufficiently sustained.
[0012] Where materials are actually transported using such universal guide devices, it is necessary to construct a moving table device from two or more universal guide devices in order to transport such materials stably. In particular, two track rails are placed parallel to each other. Plural sliders are mounted to each track rail. A table is mounted so as to span all of these sliders. The materials to be transported are placed on this table.
[0013] Where the table is moved only through a linear region or only through a curved region, if all the sliders are mounted directly to the table, no problems take place. The table can be smoothly moved. However, where the table is moved from a curved region to a straight region or vice versa continuously, if all the sliders are directly mounted to the same table, the configuration of one slider relative to the track rail is restricted by other sliders. This makes it difficult to move the table smoothly. Accordingly, where plural universal guide devices of the construction described above are used to construct the moving table device, it has been impossible to mount the sliders directly to the table.
OBJECTS AND SUMMARY OF THE INVENTION
[0014] In view of the foregoing problem, the present invention has been made. It is an object of the present invention to provide a universal guide device which can directly use sliders heretofore employed in linear guide devices and which do not need different sliders for each different radius of track rail and thus can be fabricated at lower cost than conventionally.
[0015] It is another object of the invention to provide a universal guide device in which sliders can move through two curved regions of a track rail continuously along the rail even if the two curved regions are bent in different directions and in which the sliders can move from a straight region to a curved region or vice versa continuously without sacrificing the ability of the rail to sustain a load in the straight region even if the rail contains both straight and curved regions.
[0016] It is a further object of the invention to provide a moving table device comprising plural parallel track rails and plural sliders mounted to each track rail, the moving table device being characterized in that smooth movement of the sliders is assured even if a table is supported by the sliders that are four or more in number.
[0017] To achieve the objects described above, a universal guide device in accordance with the present invention comprises: a track rail including a straight region and a curved region shaped into an arc with a given radius of curvature and having ball-rolling surfaces on both its side surfaces, the ball-rolling surfaces extending longitudinally; a slider having a saddlelike cross section and mounted to span the track rail; load-rolling surfaces formed on the slider and located opposite to the rolling surfaces, respectively, of the rail; and an endless circular path for a number of balls. The circular path is formed on the slider and includes the load-rolling surfaces. The numerous balls sustain a load between each rolling surface of the track rail and each load-rolling surface of the slider. The load-rolling surfaces formed on the slider are formed linearly. The width of the curved region of the track rail is set narrower than the straight region of the rail.
[0018] In this universal guide device in accordance with the present invention, the load-rolling surfaces formed on the slider are not shaped into an arc corresponding to the curvature of the curved region of the track rail. Rather, the load-rolling surfaces are formed linearly in conformity with the rolling surfaces of the straight region of the track rail. In the present invention, however, the curved region of the rail is set narrower than the straight region of the rail. Therefore, if the rolling surfaces of the rail assume the form of an arc, and if the load-rolling surfaces of the slider are linear, the slider can engage the curved region of the rail and can move along the curved region without trouble.
[0019] When the slider is moving through the curved region of the track rail, the balls are squeezed in between the arc-shaped rolling surfaces formed longitudinally of the rail and the linear load-rolling surfaces formed on the slider and roll along the load-rolling surfaces while carrying the load. Therefore, with respect to the numerous balls rolling on the load-rolling surfaces, only some of the balls carry the load between the rolling surfaces of the rail and the load-rolling surfaces of the slider.
[0020] In this universal guide device in accordance with the present invention, the load-rolling surfaces formed on the slider are shaped linearly rather than into an arc. Therefore, the sliders of linear guide devices can be used intact. Furthermore, an operation for machining the load-rolling surface into an arc in conformity with the curvature of the track rail is dispensed with. Therefore, it is possible to fabricate a universal guide device at quite low cost. Furthermore, the linearly formed load-rolling surfaces have no directivity. Consequently, even if two curved regions bent in different directions are contained in the rail, the slider can move through these curved regions continuously.
[0021] In addition, in the universal guide device in accordance with the present invention as described above, all the balls rolling on the load-rolling surfaces of the slider bear against the rolling surfaces of the track rail within the straight region of the rail. Therefore, the ability of the slider to sustain a load is not impaired, unlike the case in which only some balls bear against the rolling surfaces in a curved region. If large loads act on the slider, the loads can be sufficiently sustained.
[0022] In the present invention, as long as the ball-rolling surfaces on the track rail side are formed on the surfaces of the rail, balls forming a row and rolling on the load-rolling surface of the slider do not simultaneously touch the arc-shaped rolling surface on the rail side. Therefore, this rolling surface may be shaped in the same way as the rolling surface of the prior art curved guide device without needing any special machining operation. Furthermore, this track rail can be easily fabricated, because one surface of the rail and the arc-shaped rolling surface formed on it can be simultaneously ground. However, where an upward facing rolling surface is formed on the top surface of a track rail, this rolling surface needs to be machined in a special manner. In particular, a downward facing load-rolling surface is linearly formed on the slider in an opposite orientation to the upward facing rolling surface of the track rail. Consequently, this upward facing rolling surface needs to have such a width that balls forming a row and rolling on the downward facing rolling surface of the slider simultaneously touch the upward facing surface.
[0023] In the universal guide device in accordance with the present invention, the slider can move through both straight and curved regions of the track rail freely. Therefore, if this rail is composed of only curved regions, the slider can move along the annular rail. That is, where attention is paid to only the curved region of the rail, the universal guide device in accordance with the invention can be regarded as a curved guide device.
[0024] As mentioned previously, in the universal guide device in accordance with the present invention, the straight and curved regions of the track rail differ in width. Therefore, it is desired to provide an intermediate rail portion connecting the straight and curved regions of the rail such that the width of the rail varies continuously in this intermediate rail portion.
[0025] Moreover, a moving table device can be built using universal guide devices of the construction in accordance with the invention as described above. Specifically, plural track rails are mounted parallel to each other on a fixed portion such as a pedestal or a base. A table is mounted to span sliders that move on these rails. However, if two or more sliders are mounted to each rail, and if all of the sliders are directly mounted to the same table, it will be difficult to move the table smoothly between the straight and curved regions of the rail, as mentioned previously.
[0026] In view of this, first and second track rails are mounted parallel to each other. Plural sliders are mounted to each of these rails. A fixed plate is made to span one slider mounted to the first rail and one slider mounted to the second rail such that these two sliders are coupled. Another fixed plate is bridged across another slider mounted to the first rail and another slider mounted to the second rail, and so on. Preferably, the table is mounted so as to be rotatable relative to the fixed plates. Where the moving table device is constructed in this way, even if the table is supported by the sliders that are four in number, the first fixed plate bridged over the first row of sliders that is the forerunner in the direction of movement and the second fixed plate bridged over the second row of sliders rotate in such a way that the sliders are oriented in the tangential direction of the rails. The distance between the sliders on the rails is made variable. Hence, the sliders can move smoothly.
[0027] Additionally, the table can be smoothly moved between the straight and curved regions of the rail by mounting the first and second rails parallel to each other, mounting plural sliders to each of the rails, and mounting the table so as to be rotatable relative to the sliders. That is, in this structure, when the sliders move through the curved region of the rail, they rotate to arbitrary directions so as to orient themselves to the tangential direction of the rails. This permits smooth movement of the sliders.
[0028] As described thus far, in the universal guide device in accordance with the present invention, the load-rolling surfaces formed on the sliders are only required to be shaped linearly rather than into an arc. Therefore, the sliders of numerous linear guide devices available on the market can be used intact. Moreover, it is not necessary to machine the load-rolling surfaces in conformity with the curvature of the rails. In consequence, the sliders can be manufactured easily and inexpensively.
[0029] Since the load-rolling surfaces formed on the sliders have no directivity, if each track rail has two curved regions bent in different directions, the sliders can move through the curved regions continuously along the rail. For example, materials can be guided freely along a track having a high degree of freedom (e.g., consisting of a combination of straight lines and curved lines such as an S-shaped track).
[0030] Because the load-rolling surfaces formed on the sliders are linear, all the balls rolling on the load-rolling surfaces of the sliders bear against the rail in the straight regions and sustain the load. Therefore, the sliders can exhibit sufficient ability to sustain the load within these straight regions. If straight and curved lines are intermingled on the rail, the sliders can move through the straight and curved regions continuously without sacrificing the ability of the rail in the straight regions to sustain the load.
[0031] Other objects and features of the invention will appear in the course of the description thereof, which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] [0032]FIG. 1 is a plan view of a universal guide device in accordance with a first embodiment of the present invention;
[0033] [0033]FIG. 2 is a perspective view of one slider and the straight guide rail portion shown in FIG. 1;
[0034] [0034]FIG. 3 is a front elevation in cross section of the slider and straight guide rail portion shown in FIG. 2, and in which the slider is mounted on the rail;
[0035] [0035]FIG. 4 is a plan view in cross section of the slider and straight guide rail shown in FIGS. 2 and 3, showing the manner in which balls are rolling and circulating through a circular path when the slider is moving along the rail;
[0036] [0036]FIG. 5 is a front elevation in cross section similar to FIG. 3, but in which the slider is mounted on a curved guide rail portion;
[0037] [0037]FIG. 6 is a plan view in cross section of the slider and curved guide rail portion shown in FIG. 5, showing the manner in which balls are rolling through circular paths when the slider is moving along the rail;
[0038] [0038]FIG. 7 is a fragmentary plan view of a rolling surface formed on the top surface of a curved guide rail portion, showing the manner in which balls are rolling on the rolling surface;
[0039] [0039]FIG. 8 is an enlarged cross section of a rolling surface formed on the top surface of a curved guide rail portion and a load-rolling surface of a slider, showing the manner in which balls are rolling between the rolling surface on the rail and the load-rolling surface of the slider;
[0040] [0040]FIG. 9 is a plan view of a universal guide device that can be fabricated by making use of a combination of straight guide rail portions and curved guide rail portions in accordance with the first embodiment;
[0041] FIGS. 10 ( a )- 10 ( b ) are plan views of S-shaped rails each consisting of two split guide rail portions;
[0042] [0042]FIG. 11 is a fragmentary plan view of an intermediate rail portion in accordance with the first embodiment of the invention;
[0043] [0043]FIG. 12 is a fragmentary enlarged plan view of portion A of FIG. 11;
[0044] [0044]FIG. 13 is an enlarged plan view of portion B of FIG. 11;
[0045] [0045]FIG. 14 is a front view in cross section of a universal guide device in accordance with a second embodiment of the invention;
[0046] [0046]FIG. 15 is an enlarged cross section of main portions of the curved guide rail portions shown in FIG. 14;
[0047] [0047]FIG. 16 is a cross-sectional view of the curved guide rail portion shown in FIGS. 14 and 15, but in which the rail portion has been ground at both side surfaces and finished to a given width;
[0048] [0048]FIG. 17 is a fragmentary plan view of a moving table device forming a third embodiment of the invention, the moving table device using a universal guide device in accordance with the invention;
[0049] [0049]FIG. 18 is a cross-sectional view taken along line XVIII-XVIII of FIG. 17;
[0050] [0050]FIG. 19 is a perspective view of a rotary bearing used for the moving table device shown in FIGS. 17 and 18;
[0051] [0051]FIG. 20 is a plan view of this moving table device, showing the manner in which a table is moved;
[0052] [0052]FIG. 21 is a plan view of a fragmentary plan view of a moving table device built forming a fourth embodiment of the invention and using a universal guide device in accordance with the invention;
[0053] [0053]FIG. 22 is a diagram illustrating the disposition of the slider of the moving table device shown in FIG. 21 in a curved region;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] Referring to FIG. 1, there is shown a universal guide device in accordance with a first embodiment of the present invention. A track rail 1 is mounted to a fixed portion such as a pedestal or a base. Sliders 2 can move along the rail 1 . This rail 1 is composed of a straight guide rail portion 1 A, a curved guide rail portion 1 B shaped into an arc with a given radius, and an intermediate rail portion 1 C connecting these rail portions 1 A and 1 B. The sliders 2 can move on these rail portions 1 A, 1 B, and 1 C freely.
[0055] [0055]FIG. 2 is a perspective view of the straight guide rail portion 1 A and one slider 2 mounted on this rail portion 1 A. FIG. 3 is a front view in cross section taken axially of the straight guide rail portion 1 A. The straight rail portion 1 A has a substantially rectangular cross section. Two side ball-rolling surfaces 10 a and two top ball-rolling surfaces 10 b extend longitudinally. Balls 3 roll on these four rolling surfaces 10 a , 10 b . The two side ball-rolling surfaces 10 a are formed on the opposite side surfaces of the straight guide rail portion 1 A, while the two top ball-rolling surfaces 10 b are formed around the opposite edges, respectively, of the top surface of the guide rail portion 1 A. The side ball-rolling surfaces 10 a are tilted at an angle of 30° downwardly from the horizontal in the paper. The top ball-rolling surfaces 10 b face vertically upward. Bolt-mounting holes 11 are formed in the straight guide rail portion 1 A and spaced regularly from each other longitudinally along the rail portion 1 A. Anchoring bolts (not shown) are inserted in the bolt-mounting holes 11 to mount the rail portion 1 A fixedly to the fixed portion.
[0056] Referring particularly to FIGS. 2 and 3, each of the sliders 2 described above comprises a movable block 4 and two covers 5 mounted to the front and rear end surfaces, respectively, of the block 4 . The movable block 4 is provided with tapped holes 42 into which the anchoring bolts are screwed. The movable block 4 has a mounting surface 41 on which a movable body such as a table is mounted. An endless circular path for the balls 3 is formed inside the slider by mounting the covers 5 to the movable block 4 . Seal members 6 that make a sliding contact with the track rail 1 are mounted to the covers 5 , respectively, to prevent dust adhering to the rail 1 from entering the slider 2 during movement of the slider.
[0057] Referring particularly to FIG. 3, the aforementioned movable block 4 has a horizontal portion 4 a and a pair of skirt portions 4 b descending from the horizontal portion 4 a . The block 4 has a saddlelike cross section. The above-described mounting portion 41 is formed in the horizontal portion 4 a . Two straight load-rolling surfaces 43 a are formed on the inner surfaces of the skirt portions 4 b of the horizontal portion 4 a and located opposite to side ball-rolling surfaces 10 a of the straight guide rail portion 1 A. Two straight load-rolling surfaces 43 b are formed on the bottom surface of the horizontal portion 4 a and located opposite to the top ball-rolling surfaces lob of the straight guide rail portion 1 A. Ball return holes 44 a corresponding to the load-rolling surfaces 43 a are formed in the skirt portions 4 b , respectively. Ball return holes 44 b corresponding to the load-rolling surfaces 43 b are formed in the horizontal portion 4 a . U-shaped direction change paths 51 (FIG. 4) are formed in the covers 5 , respectively, to connect the load-rolling surfaces 43 a and 43 b with the ball return holes 44 a and 44 b , respectively, thus forming an endless circular path for balls.
[0058] Some of the balls 3 sustain a load between the ball-rolling surface 10 a of the straight guide rail portion 1 A and the load-rolling surface 43 a of the movable block 4 . The other balls 3 sustain a load between the top ball-rolling surface 10 b of the straight guide rail portion 1 A and the load-rolling surface 43 b of the movable block 4 . As each slider 2 moves, the balls 3 finish rolling over the load-rolling surfaces 43 a and 43 b . Then, the balls 3 are relieved of the load and enter the direction change path 51 in one cover 5 . The balls then roll through the ball return holes 44 a and 44 b in the movable block 4 in a direction opposite to the direction of rolling motion on the load-rolling surfaces 43 a and 43 b while maintained in an unloaded state. After finishing rolling through the ball return holes 44 a and 44 b , the balls 3 enter again into the gap between the straight guide rail 1 A and the movable block 4 through the direction change path 51 in the other cover 5 , and roll on the load-rolling surfaces 43 a and 43 b while sustaining a load.
[0059] Ball-holding plates 45 and 46 are mounted to the bottom ends of the skirt portions 4 b and the horizontal portion 4 a , respectively, of the movable block 4 . The ball-holding plates 45 and 46 are stamped from a metal plate or formed from a hard synthetic resin by injection molding or other method. The ball-holding plates 45 and 46 prevent the balls 3 rolling on the ball-rolling surfaces 10 a , 10 b from coming off the slider 2 when the slider 2 is removed from the track rail 1 .
[0060] [0060]FIG. 4 shows the manner in which the balls 3 are rolling on the side rolling surfaces 10 a formed on the side surfaces of the straight guide rail portion 1 A and circulating through the path when each slider 2 is moving along the straight guide rail portion 1 A. The balls 3 rolling on the top ball-rolling surfaces lob formed on the top surface of the straight guide rail portion 1 A make similar rolling and circulating motion.
[0061] As mentioned previously, the direction change paths 51 corresponding to the load-rolling surfaces 43 a and 43 b are formed in the two covers 5 mounted to the opposite end surfaces, respectively, of the movable block 4 . By mounting the covers 5 to the movable block 4 , the slider 2 forms an endless circular path for the balls 3 as shown. The rolling surfaces 10 a and 10 b extend linearly and longitudinally along the straight guide rail portion 1 A. Also, the load-rolling surfaces 43 a and 43 b of the slider 2 opposite to the rolling surfaces 10 a and 10 b , respectively, are formed linearly. Therefore, all the balls 3 simultaneously rolling on the load-rolling surfaces 43 a and 43 b are in contact with the rolling surfaces 10 a and 10 b , respectively, of the straight guide rail portion 1 A, as shown in FIG. 4. That is, when the slider 2 is moving along the straight guide rail portion 1 A, none of the balls 3 are idling without sustaining a load between the rolling surface 10 a or 10 b on the side of the track rail 1 and the load-rolling surface 43 a or 43 b on the side of the slider 4 . If a large load is applied to the slider 2 , the load is sustained reliably, and the slider 2 can be moved smoothly.
[0062] [0062]FIG. 5 is a front view in cross section of the curved guide rail portion 1 B and one slider 2 mounted on it. This curved guide rail portion 1 B is shaped into a cross-sectional shape similar to that of the above-described straight guide rail portion. This curved guide rail portion 1 B is shaped into an arc having a given curvature R in the longitudinal direction. Side rolling surfaces 12 a continuous with the side rolling surfaces 10 a , respectively, formed on the opposite side surfaces of the straight guide rail portion 1 A are formed on the opposite side surfaces of the curved guide rail portion 1 B. Top rolling surfaces 12 b continuous with the top rolling surfaces 10 b , respectively, formed on the top surface of the straight guide rail portion 1 A are formed on the top surface of the curved guide rail portion 1 B.
[0063] Since the curved guide rail portion 1 B is formed to have a given curvature, if the width L 2 of the curved guide rail portion 1 B is set equal to the width L 1 of the straight guide rail portion 1 A, then the inner side surface of the curved guide rail portion 1 B may be hindered by the skirt portions 4 b or with the covers 5 . Therefore, the width L 2 of the curved guide rail portion 1 B is set smaller than the width L 1 of the straight guide rail portion 1 A. For comparison, the cross section of the straight guide rail portion 1 A is indicated by the dot-and-dash line. When the width L 2 of the curved guide rail portion 1 B is set smaller than the width L 1 of the straight guide rail portion 1 A, only the inner side surface of the curved guide rail portion 1 B needs to be ground, as shown in FIG. 5. Alternatively, both inner and outer side surfaces may be ground, as shown in FIG. 16.
[0064] [0064]FIG. 6 shows the manner in which the balls 3 are rolling and circulating through a circular path when the slider 2 is moving along the curved guide rail portion 1 B. The balls 3 are shown to roll on the rolling surfaces 12 a formed on the opposite side surfaces of the curved guide rail portion 1 B. The rolling surfaces 12 a are shaped into arcs longitudinally of the curved guide rail portion 1 B. On the other hand, the load-rolling surfaces 43 a of the slider 2 opposite to the rolling surfaces 12 a are shaped linearly. Thus, as shown in FIG. 6, inside of the curved guide rail portion 1 B, only those of the balls 3 which are rolling close to both ends of the load-rolling surfaces 43 a bear against the rolling surfaces 12 a . Outside of the curved guide rail portion 1 B, only those of the balls 3 which roll across the centers of the load-rolling surfaces 43 a bear against the rolling surfaces 12 a . That is, when the slider 2 is moving along the curved guide rail portion 1 B, only parts of the balls 3 rolling on the load-rolling surfaces 43 a of the slider 2 sustain a load, whereas the other balls 3 idle without sustaining a load. It may be considered that all the balls 3 rolling on the load-rolling surfaces 43 a bear against the rolling surfaces 12 a of the curved guide rail portion 1 B, depending on the curvature of the curved guide rail portion 1 B. Even in this case, some of the balls 3 hardly sustain a load and idle. Even if some of the balls 3 idle without bearing against the rolling surfaces 12 a of the curved guide rail portion 1 B in this way, these balls 3 do not disengage from between the load-rolling surfaces 43 a and the rolling surfaces 12 , because the ball-holding plate 46 is mounted to the slider 2 .
[0065] [0065]FIG. 7 shows the manner in which the balls 3 are rolling on the load-rolling surfaces 43 b formed on the horizontal portion 4 a of the slider 2 . That is, FIG. 7 is a perspective of the slider 2 as taken from above the curved guide rail portion 1 B. Since the load-rolling surface 43 b of the slider 2 is straight while the opposite rolling surface 12 b of the curved guide rail portion 1 B is shaped into an arc, if the width of the rolling surfaces 12 b is set equal to the width of the side rolling surfaces 12 a on the curved guide rail portion and the width of the load-rolling surfaces 43 b , some of the balls 3 rolling on the load-rolling surface 43 b on the side of the slider 2 bear against the inner surface of the rolling surface 12 b . The others come off the rolling surface 12 b and bear against the top surface of the curved guide rail portion 1 B. Consequently, the balls 3 cannot smoothly circulate through the endless circular path in the slider 2 .
[0066] Therefore, the rolling surface 12 b formed on the top surface of the curved guide rail portion 1 B is shaped to have a larger groove width d than the load-rolling surfaces 43 b such that all the balls 3 which roll on the load-rolling surfaces 43 b can simultaneously bear against the rolling surface 12 b , as shown in FIG. 7. FIG. 8 is an enlarged view showing the manner in which the balls 3 touch rolling surfaces between the load-rolling surface 43 b on the side of the slider 2 and the rolling surface 12 b on the side of the curved guide rail portion 1 B. The solid line indicates the manner in which the balls touch the rolling surfaces in cross section α-α of FIG. 7. The dot-and-dash line indicates the manner in which the balls touch the rolling surfaces in cross section B-B. The rolling surfaces 12 b are set wider than the load-rolling surfaces 43 b . Furthermore, the rolling surfaces 12 b are shaped into an arc having a curvature in the horizontal direction in the plane of FIG. 8. Therefore, as the balls 3 roll on the straight load-rolling surfaces 43 b , the positions at which the balls touch the rolling surfaces 12 b move right and left. The balls roll on the load-rolling surfaces 43 b while sustaining a load between the slider and the curved guide rail portion at all times.
[0067] In the universal guide device in the present invention in this way, the curved guide rail portion 1 B is set narrower than the straight guide rail portion 1 A. Where the top surface of the track rail 1 needs a rolling surface for the balls 3 , only the rolling surface 12 b on the top surface of the curved guide rail portion 1 B is set wider than the load-rolling surface 43 b on the side of the slider 2 . Hence, the slider 2 can be moved freely between the straight guide rail portion 1 A and the curved guide rail portion 1 B, though the slider 2 is the same as the prior art linear guide device structure.
[0068] However, when the slider 2 moves along the curved guide rail portion 1 B, the number of the balls 3 bearing against the side rolling surfaces 12 a of the curved guide rail portion 1 B is fewer than the number of the balls 3 bearing against the side rolling surfaces 10 a of the straight guide rail portion 1 A. Therefore, it cannot be denied that the ability of the slider 2 to sustain a load in the curved region of the track rail 1 decreases. However, the ability of the straight region to sustain a load is not sacrificed for the sake of the curved region. If a large load acts on the slider 2 in the straight region, the load can be sufficiently sustained.
[0069] In the universal guide device in accordance with the present invention as described above, the load-rolling surfaces 43 a and 43 b of the slider 2 are shaped linearly and have no directivity. Therefore, the slider 2 can move along the curved guide rail portion 1 B without trouble, irrespective of whether the curved guide rail portion 1 B is bent right or left. For this reason, as shown in FIG. 9, the slider 2 can be moved along an S-shaped track rail 1 built by combining two curved guide rail portions 1 B bent in different directions. Furthermore, it is not always necessary that all the successive curved guide rail portions 1 B within the continuous track rail 1 be shaped into arcs with uniform radius. The slider can be moved freely even if curved rail portions having different radii are combined.
[0070] As shown in FIG. 10, the curved guide rail portion 1 B formed at uniform curvature is cut into two rail pieces 16 and 17 . Then, one rail piece 17 is rotated through 180° and combined with the other rail piece 16 , thus forming an S-shaped track rail 1 . Even in this case, the slider 2 can be moved along the track rail 1 freely.
[0071] Referring next to FIG. 11, there is shown the intermediate rail portion 1 C connecting the straight guide rail portion 1 A and the curved guide rail portion 1 B. It may be possible to construct the track rail 1 by connecting the straight guide rail portion 1 A and curved guide rail portion 1 B without using the intermediate rail portion 1 C. As mentioned previously, the curved guide rail portion 1 B is set narrower than the straight guide rail portion 1 A. In addition, the rolling surface 12 b of the curved guide rail portion 1 B is set wider than the top rolling surface 10 b of the straight guide rail portion 1 A. Therefore, if the straight guide rail portion 1 A and curved guide rail portion 1 B are connected directly, then smooth movement of the slider 2 may be somewhat hindered. Consequently, in the present invention, the intermediate rail portion 1 C is interposed between the straight guide rail portion 1 A and the curved guide rail portion 1 B to transport the slider 2 from the straight guide rail portion 1 A to the curved guide rail portion 1 B and vice versa smoothly.
[0072] This intermediate rail portion 1 C assumes a cross-sectional shape similar to that of the straight guide rail portion 1 A, and extends linearly. The intermediate rail portion 1 C has ball-rolling surfaces that continuously connect with the rolling surfaces 10 a and 10 b of the straight guide rail portion 1 A and with the rolling surfaces 12 a and 12 b of the curved guide rail portion 1 B. Since the curved guide rail portion 1 B is set narrower than the straight guide rail portion 1 A, the side surface 14 of the intermediate rail portion 1 C that is continuous with the inner side surface of the curved guide rail portion 1 B is cut out obliquely on the side at the end of the curved guide rail portion 1 B as indicated by the dot-and-dash line of FIG. 13. The width decreases gradually from the straight guide rail portion 1 A toward the curved guide rail portion 1 B. Thus, the side rolling surface 10 a formed on the side of the straight guide rail portion 1 A is continuous with the rolling surface 12 a formed on the side surface of the curved guide rail portion 1 B, without step-wise changes. The balls can roll smoothly between the rolling surfaces 10 a and 12 a .
[0073] As shown in FIG. 11, a ball-rolling surface 13 b that is continuous with the rolling surface 10 b of the straight guide rail portion 1 A and with the rolling surface 12 b of the curved guide rail portion 1 B is formed on the top surface of the intermediate rail portion 1 C. As shown in FIGS. 12 and 13, the width of the ball-rolling surface 13 b gradually increases on the side at the end of the curved guide rail portion 1 B. This connects the rolling surfaces 10 b and 12 b having different widths without any step-wise changes. Consequently, balls that have rolled on the rolling surface 12 b of the curved guide rail portion roll into the top rolling surface 10 b of the straight guide rail portion that is narrower than the rolling surface 12 b without being caught. In this way, the slider can be smoothly moved from the curved region to the straight region of the track rail.
[0074] Referring next to FIG. 14, there is shown a universal guide device in accordance with a second embodiment of the present invention. A track rail 7 and a slider 8 are similar in fundamental structure with their respective counterparts of the first embodiment described above. However, the rail 7 has two ball-rolling surfaces 71 a and two ball rolling surfaces 71 b on opposite sides, one pair above the other. The upper rolling surfaces 71 a are tilted at an angle of 45° upwardly. The lower rolling surfaces 71 b are tilted at an angle of 45° downwardly. The slider 8 has load-rolling surfaces 81 a and 81 b that are tilted at angles corresponding to the ball rolling surfaces 71 a and 71 b , respectively.
[0075] This FIG. 14 shows the manner in which the slider 8 is mounted to the straight region of the track rail 7 , i.e., the straight guide rail portion 7 A. A curved guide rail portion 7 B continuous with this straight guide rail portion 7 A is set narrower than the straight guide rail portion 7 A, in the same way as in the first embodiment. FIG. 15 is a front view in cross section of the curved guide rail portion 7 B, and in which the contour of the straight guide rail portion 7 A is also indicated by the dot-and-dash line.
[0076] In the universal guide device in accordance with the second embodiment constructed in this manner, the curved guide rail portion 7 B is set narrower than the straight guide rail portion 7 A in the same way as in the first embodiment. In consequence, the slider 8 can freely move between the straight guide rail portion 7 A and the curved guide rail portion 7 B.
[0077] In the embodiments given above, the present invention is applied to universal guide devices. If an annular track rail is composed by combining plural curved guide rail portions of the structure described above, the slider can be moved along this rail. A curved guide device can be easily constructed.
[0078] In the present invention, the load-rolling surfaces 43 a and 43 b formed on the slider 2 are shaped linearly. Therefore, a universal guide device can be fabricated by making direct use of sliders of the existing linear guide devices. Accordingly, in the embodiments described above, the curved guide rail portion 1 B is set narrower than the straight guide rail portion 1 A to permit the slider of the straight guide device to move along the curved guide rail portion 1 B as it is. However, due to the degree of curvature of the curved guide rail portion 1 B, it may be impossible to adapt the structure sufficiently only with a decrease in the width of the curved guide rail portion 1 B. The curved guide rail portion 1 B may be hindered in its movement by the skirt portions 4 b of the slider 2 or with the covers 5 . Accordingly, in this case, the length of the slider 2 taken longitudinally with regard to the track rail 1 is reduced, thus preventing interference between the curved guide rail portion 1 B and the slider 2 .
[0079] Referring to FIGS. 17 and 18, there is shown a moving table device using a universal guide device in accordance with the present invention, the moving table device forming a third embodiment of the invention. Track rails 1 and 1 ′ are mounted to a fixed portion such as a pedestal or a base. Sliders 2 can move along the rails 1 and 1 ′. A table 92 is mounted to the sliders.
[0080] The track rails 1 and 1 ′ are composed of the first rail 1 and the second rail 1 ′ that extend in parallel and are uniformly spaced from each other. The rail 1 comprises a straight guide rail portion 1 A, a curved guide rail portion 1 B shaped into an arc with a given curvature, and an intermediate rail portion 1 C connecting the straight guide rail portion 1 A and the curved guide rail portion 1 B. Similarly, the rail 1 ′ comprises a straight guide rail portion 1 ′A, a curved guide rail portion 1 ′B shaped into an arc with a given curvature, and an intermediate rail portion 1 ′C connecting the straight guide rail portion 1 ′A and the curved guide rail portion 1 ′B. The radii of curvature of the curved guide rail portions 1 B and 1 ′B are set to R 1 and R 2 , respectively. The centers O of their radii of curvature are coincident.
[0081] Plural (e.g., 2) sliders 2 are mounted to each of the rails 1 and 1 ′. Four sliders in total support the table. The sliders 2 can move freely on the first rail 1 ( 1 A, 1 B, 1 C) and on the second rail 1 ′ ( 1 ′A, 1 ′B, 1 ′C). A pair of fixed plates 91 is mounted across the first and second rows of the sliders 2 as viewed in the direction of motion on the rails 1 and 1 ′. The fixed plates 91 assume an elongated rectangular form and are mounted to the top surfaces of the sliders 2 with fixing means such as screws. That is, the fixed plates 91 are bridged across the sliders 2 that are adjacent to each other looking down the longitudinal direction of the rails 1 and 1 ′ (i.e., in the direction of the array of the rail portions).
[0082] The table 92 is mounted so as to be rotatable relative to the fixed plates. A shaft 93 is mounted to the bottom surface of the table 92 . Rotary bearings 90 for rotatably holding the shaft 93 are mounted to the top surfaces of the fixed plates 91 . The rotary bearings 90 permit the table 92 to rotate relative to the fixed plates while the bearings receive a load from the table 92 . The rotary bearings 90 are mounted in housings 94 , which in turn are mounted to the fixed plates 91 . Each of the rotary bearings 90 has an outer race 90 a mounted to the housing and an inner race 90 b mounted to the shaft 93 .
[0083] [0083]FIG. 19 shows one of the rotary bearings 90 . A V-shaped rolling surface is formed in both the outer race 90 a and inner race 90 b . A roller-rolling path of substantially rectangular cross section is formed between these rolling surfaces. Plural rollers 95 are arranged in the roller-rolling path and tilted alternately in directions at right angles to each other. The rollers 95 roll in the roller-rolling path while receiving a load. Spacers 96 are interposed between adjacent rollers 95 to maintain the rollers 95 in a given disposition.
[0084] In the roller-rolling path, the two rollers 95 horizontally adjacent to the same spacer 96 have axes that are perpendicular to each other. These rollers 95 are classified as outward facing rollers 95 a and inward facing rollers 95 b . The spacers 96 maintain the outward facing rollers 95 a in such a disposition that their axes C face toward the center of rotation B lying at the center of rotation of the outer race 90 a and the inner race 90 b.
[0085] [0085]FIG. 20 shows the manner in which the track rails 1 and 1 ′ consisting of the rail portions 1 A, 1 B, 1 C and rail portions 1 ′A, 1 ′B, 1 ′C, respectively, are combined into an S-shaped form. The fixed plates 91 and the table 92 move on this S-shaped rail. When moving on the curved rail portions 1 B and 1 ′B, the sliders 2 are directed in the tangential direction of the curved rail portions 1 B and 1 ′B. Therefore, the fixed plates 91 mounted to the sliders 2 rotate about the center O of the radius of curvature. As a result, the distance between the sliders 2 moving on the inner track rail 1 decreases, while the distance between the sliders 2 moving on the outer track rail 1 ′ increases. Since the fixed plates 91 are rotatably mounted to the table 92 , the plates permit such variations in the distances between the sliders 2 and enable smooth motion of the sliders 2 .
[0086] [0086]FIGS. 21 and 22 show a moving table device using a universal guide device in accordance with the present invention, the moving table device forming a fourth embodiment of the present invention. In this fourth embodiment, the first track rail 1 and the second track rail 1 ′ are mounted in parallel, and two sliders 2 are mounted to both of the rails 1 and 1 ′. These four sliders 2 support the table 92 , in the same way as in the third embodiment described above. However, the moving table device in accordance with the fourth embodiment differs from the moving table device in accordance with the third embodiment in that the four sliders 2 have their respective rotary bearings 90 and that the table 92 is rotatably held by the rotary bearings 90 . The rotary bearings 90 are similar in structure to the rotary bearings used in the third embodiment. Shafts mounted at the four corners of the table 92 are rotatably held.
[0087] In the moving table device in accordance with this embodiment, the sliders 2 support the four corners of the table 92 and so the table 92 can be held more stably than in the third embodiment. Since the four sliders 2 are rotatably held to the table, the sliders 2 moving on the curved guide rail portions 1 B and 1 ′B rotate arbitrarily and independently and are directed in tangential directions θ1, θ2, θ3, and θ4 of the curved guide rail portions 1 B, 1 ′B, as shown in FIG. 22. This permits smooth motion of the sliders 2 .
[0088] When the table 92 moves between the track rails 1 and 1 ′ having different radii of curvature as encountered when moving from the straight regions 1 A, 1 ′A of the rails 1 , 1 ′ to the curved regions 1 B, 1 ′B, if the distance between the sliders 2 is kept constant, the sliders 2 will be hindered in their movement by the rails 1 and 1 ′, hindering smooth movement of the table 92 . However, gaps are provided between the sliders 2 and the rails 1 , 1 ′ by setting the width of rails 1 and 1 ′ narrower as mentioned above. The gaps eliminate the interference between the sliders 2 and the rails 1 , 1 ′, assuring smooth movement of the sliders 2 .
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The present invention offers a universal guide device capable of using the sliders of conventional straight guide devices intact. The universal guide device does not need a different slider for each different radius of track rail. The universal guide device can be manufactured at lower cost than heretofore. This universal guide device in accordance with the invention comprises a track rail and sliders mounted to the rail via balls circulating through endless circular paths. The rail has at least one straight region and at least one curved region shaped in an arc with a given radius of curvature. Each of the sliders is of saddlelike cross section. The sliders span the rail. The sliders have ball-rolling surfaces shaped linearly. The curved region of the rail is set narrower than the straight region of the rail.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to semiconductor wafer preparation and more specifically to in situ metrology for process parameter control during wafer processing.
[0003] 2. Description of the Related Art
[0004] As is well known, semiconductor fabrication includes several stages during which an underlying substrate is subjected to the formation and removal of various layers. The continuous demand for smaller feature sizes and tighter surface planarity in conjunction with the constant quest to increase wafer throughput requires implementing a process state monitoring and endpoint detection method capable of discontinuing the processing of a target layer once a target thickness has been achieved.
[0005] Recently, eddy current sensors (ECS) are starting to be used to measure changes in film properties. For more information on these new methodologies for using eddy current sensors, reference may be made to “INTEGRATION OF EDDY CURRENT SENSOR BASED METROLOGY WITH SEMICONDUCTOR FABRICATION TOOLS” having the U.S. patent application Ser. No. 10/186,472, filed on Jun. 28, 2002. The disclosure of this Patent Application is incorporated herein by reference. The ECS sensors rely on the induction of a circular current in a sample by the fluctuating electromagnetic field of a test coil proximate to the object being probed. Fluctuating electromagnetic fields are created as a result of passing an alternating current through the coil. The fluctuating electromagnetic fields induce eddy currents, which perturb the applied field and change the inductance of the coil.
[0006] [0006]FIG. 1 is a simplified schematic diagram of the principle upon which an eddy current sensor operates. An alternating current flows through coil 108 defined in close proximity to the conducting object 102 . The electromagnetic field of the coil 108 induces eddy currents 104 in conducting object 102 . The magnitude and the phase of the eddy currents 104 in turn affect the loading on the coil 108 , causing the impedance of the coil 108 to be impacted by the eddy currents 104 . This impact is measured and calibrated in terms of proximity of conducting object 102 and/or thickness of the object 102 if the thickness of the object 102 is significantly less than the field penetration depth. As can be seen, distance 106 impacts the effect of eddy currents 104 on coil 108 . As such, if object 102 moves, the signal from the sensor monitoring the impact of eddy currents 104 on coil 108 will also change.
[0007] In a chemical mechanical planarization (CMP) operation, a wafer carrier includes an isolated built-in eddy current sensor for measuring the thickness of the thin film layer being processed during the CMP operation. The wafer carrier includes a carrier film designed to support the wafer. During the planarization operation, the rotating carrier, the built in eddy current sensor, and wafer are pressed against the polishing pad, planarizing the surface of the wafer.
[0008] Unfortunately, using eddy current sensors for detecting an endpoint of the target layer or measuring the thickness of the target layer has certain negative aspects. For instance, the plot 200 shown in FIG. 2 depicts the eddy current sensor signals generated in a center and edge of a wafer. A graph 114 shows the changes in eddy current voltage versus time during the planarization operation. In graph 114 , changes in eddy current voltage is sensed by an isolated eddy current sensor defined in the center of the wafer while a graph 116 shows the changes in eddy current voltage during the planarization operation sensed by another isolated eddy current sensor defined in the edge of the wafer. Normally, the eddy current sensor signals undulate sinusoidally, with each signal undulation following a frequency of the carrier rotation. A shown in FIG. 2, however, despite both signals undulating sinusoidally, the signal amplitude in the edge graph 116 is shown to be considerably higher than the amplitude in the center graph 114 .
[0009] Furthermore, the probed thin film layer allows the electromagnetic field to penetrate the thin film layer so as to reach conductive objects located in the sensing vicinity. Generally, the configuration of the external objects is asymmetric with regard to the trajectory of the rotating sensor. However, rotational proximity variation results in sinusoidal variation in the signal amplitude attributed to rotation of the wafer carrier and thus the eddy current sensors in a non-uniform external media.
[0010] The variation in the sinusoidal signal amplitude is caused by the sensitivity of the eddy current sensors to a wide spectrum of parameters. For instance, among many other parameters, it has been established that eddy current sensors are sensitive to variation in carrier film thickness, standoff, temperature, and pressure. Additionally, the magnitude and phase of the eddy current generated in the probed thin film layer is sensitive to the properties of the thin film layer (e.g., thickness, resistivity, topography, etc.) as well as thin film layer/sensor proximity.
[0011] By way of example, the “standoff” parameter, i.e., the distance between the layer to be polished and the eddy current sensor surfaces, may differ for a number of reasons. A substantial variation in the standoff is created when the carrier film thickness varies (e.g., between +/− a few mils). The standoff further varies as a result of changes in the thickness of the carrier film due to compression of the carrier film being applied to the polishing pad with different degrees of pressure. The thickness of the carrier film and thus the standoff furthermore changes once the leading edge of the rotating wafer digs into the moving polishing pad at the point of contact. At this point, the pressure applied at the point of contact causes the carrier film to be compressed, varying the standoff, and thus the amplitude of the eddy current signal amplitude. As can be appreciated, it is extremely difficult to calibrate for all the parameters affecting the standoff, which ultimately negatively impacts the thickness measurement by the sensor.
[0012] Another variable parameter affecting the eddy current signal amplitude is having non-uniform temperature gradiance across the wafer surface. For instance, the temperature of the wafer leading edge increases as the wafer leading edge comes into contact with the moving polishing pad. Then, the temperature of the wafer trailing edge increases as the wafer trailing edge comes into contact with the polishing pad, increasing the temperature of the wafer trailing edge. The sensitivity of the eddy current sensor to variation in temperature, directly influencing the eddy current sinusoidal signal amplitude. Again, making it extremely difficult to calibrate for temperature variances impacting the thickness measurement of the eddy current sensors.
[0013] Additionally, the sinusoidal signal amplitude differs depending on the sensor being defined within the wafer carrier close to the wafer center or the edge of the wafer. The signal amplitude increases as the sensors are defined further away from the wafer center.
[0014] As can be appreciated, the conjunctive effects of these parameters has introduced an unacceptably high amount of error and unpredictability into the thickness measurement or endpoint detection using the eddy current sensor signals, leading to underpolishing or overpolishing of the processed wafer layers, damaging the wafers and thus, reducing wafer throughput and yield.
[0015] In view of the foregoing, there is a need for a flexible methodology and system capable of determining a thickness of a target layer by controlling the process parameters.
SUMMARY OF THE INVENTION
[0016] Broadly speaking, the present invention fills these needs by determining a thickness of a wafer layer in real time or an endpoint of a wafer layer by averaging anti-phase sinusoidal signals generated by a plurality of complimentary sensors defined substantially equally along a radius of a wafer carrier configured to hold the wafer to be processed. It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, a device, or a method. Several inventive embodiments of the present invention are described below.
[0017] In one embodiment, a method for detecting a thickness of a layer of a wafer is provided. The method includes defining a particular radius of a wafer carrier configured to engage the wafer to be processed. The method also includes providing a plurality of sensors configured to create a set of complementary sensors. Further included in the method is distributing the plurality of sensors along the particular radius within the wafer carrier such that each sensor of the plurality of sensors is out of phase with an adjacent sensor by a same angle. The method also includes measuring signals generated by the plurality of sensors. Further included is averaging the signals generated by the plurality of sensors so as to generate a combination signal. The averaging is configured to remove noise from the combination signal such that the combination signal is, capable of being correlated to identify the thickness of the layer.
[0018] In another embodiment, a method for detecting a thickness of a wafer layer of a wafer is provided. The method includes defining a particular radius of a wafer carrier designed to engage the wafer to be processed. The method further includes providing a pair of sensors and distributing the pair of sensors along the particular radius within the wafer carrier such that a first sensor of the pair of sensors is out of phase with a second sensor of the pair by a predetermined angle. The method further includes measuring signals generated by the first sensor and the second sensor of the pair of sensors. Also included is averaging the signals generated by the first sensor and the second sensor so as to generate a combination signal. The averaging is configured to remove noise from the combination signal capable of being correlated to identify the thickness of the layer.
[0019] In yet another embodiment, an apparatus for detecting a thickness of a conductive layer of a wafer configured to be engaged by a wafer carrier is provided. The apparatus includes a plurality of sensors configured to detect a signal produced by a magnetic field generated by a magnetic field enhancing source. The plurality of sensors are defined along a circle defined within the wafer carrier such that each sensor of the plurality of sensors is out of phase with an adjacent sensor by a predetermined angle. The average of signals generated by the plurality of sensors is configured to create a combination signal.
[0020] The advantages of the present invention are numerous. Most notably, the embodiments of the present invention allow implementation of any combination of equally distributed sensors defined along the same circle to eliminate signal undulation caused by the corresponding circular motion. In this manner, the sinus clear signal precisely correlates to the thickness of the metal film being removed, providing a reliable process state monitoring and end point detection approach for use in semiconductor fabrication process, such as a CMP process. Another advantage is that the rotationally non-disturbed combination signal is recorded in real time due to usage of algorithmic averaging procedures. The algorithmic averaging procedure advantageously real time monitoring metrology. Yet another advantage is that by using uniformly distributed sensors defined along a particular circle, periodic motion related (e.g., undulating) signal component is automatically and completely suppressed without requiring any additional adjustments and irrespective of complexity ( i.e., signals having a simple sinusoidal or other shapes in more complicated cases). Yet another advantage is that the embodiments of the present invention can be implemented in any type of CMP system (e.g., linear CMP system, rotary table CMP system, orbital CMP system, etc.). Still another advantage is that the embodiments of the present invention can be implemented in any device implementing cyclical periodic system motion to modulate the conditions in sensing space that cause signal undulation
[0021] Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, and like reference numerals designate like structural elements.
[0023] [0023]FIG. 1 is a simplified schematic diagram of the principle upon which an eddy current sensor operates.
[0024] [0024]FIG. 2 shows graphs of the signal of two isolated eddy current sensors defined by the center and edge of the wafer.
[0025] [0025]FIG. 3A is a schematic diagram of an exemplary wafer carrier including a pair of complementary eddy current sensors for measuring the thickness of a wafer layer during a chemical mechanical planarization process (CMP), in accordance with one embodiment of the present invention.
[0026] [0026]FIG. 3B is a simplified schematic top view diagram of wafer carrier and the pair of complementary eddy current sensors shown in FIG. 3A, in accordance with e embodiment of the invention.
[0027] [0027]FIG. 3C is a simplified schematic top view diagram of another pair of exemplary eddy current sensors, in accordance with e embodiment of the invention.
[0028] [0028]FIG. 3D is a simplified schematic top view diagram of an exemplary wafer carrier including three sets of complimentary ECS sensors built therein, in accordance with e embodiment of the invention.
[0029] [0029]FIG. 4 depicts graphs of sinusoidal signals generated by an exemplary pair of complimentary eddy current sensors, in accordance with still another embodiment of the invention.
[0030] [0030]FIG. 5A depicts graphs of sinusoidal signals generated by an exemplary pair of complimentary eddy current sensors, in accordance with one embodiment of the invention.
[0031] [0031]FIG. 5B depicts graphs of sinusoidal signals generated by the exemplary pair of complimentary eddy current sensors, in accordance with one embodiment of the invention.
[0032] [0032]FIG. 5C depicts graphs of sinusoidal signals generated by the exemplary pair of complimentary eddy current sensors, in accordance with one embodiment of the invention.
[0033] [0033]FIG. 6A is a simplified schematic top view diagram of a three-sensor complementary eddy current sensors for measuring thickness of a target layer, in accordance with still another embodiment of the invention.
[0034] [0034]FIG. 6B is a simplified schematic top view diagram of a four-sensor complementary eddy current sensors for measuring thickness of a target layer, in accordance with still another embodiment of the invention.
[0035] [0035]FIG. 6C is a simplified schematic top view diagram of a five-sensor complementary eddy current sensors for measuring thickness of a target layer, in accordance with still another embodiment of the invention.
[0036] [0036]FIG. 6D is a simplified schematic top view diagram of a six-sensor complementary eddy current sensors for measuring thickness of a target layer, in accordance with still another embodiment of the invention.
[0037] [0037]FIG. 6E is a simplified schematic top view diagram of a seven-sensor complementary eddy current sensors for measuring thickness of a target layer, in accordance with still another embodiment of the invention.
[0038] [0038]FIG. 6F is a simplified schematic top view diagram of an eight-sensor complementary eddy current sensors for measuring thickness of a target layer, in accordance with still another embodiment of the invention.
[0039] [0039]FIG. 6G is a simplified schematic top view diagram illustrating the implementation of multi-sets of complementary sensors to measure the thickness of a target layer, in accordance with still another embodiment of the invention.
[0040] [0040]FIG. 6H is a simplified schematic top view diagram illustrating the implementation of multi-sets of complementary sensors to measure the thickness of a target layer, in accordance with still another embodiment of the invention.
[0041] [0041]FIG. 7 is a flowchart diagram depicting operations performed to determine the thickness of a metal film using a plurality of complimentary sensors, in accordance with still another embodiment of the present invention.
[0042] [0042]FIG. 8 is a flow chart diagram illustrating method operations performed in detecting etch endpoint through implementing a plurality of complementary sensors, in accordance with yet another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] Inventions for accurately determining an endpoint or a thickness of a wafer layer are provided. In one embodiment, a plurality of sinusoidal signals generated by a plurality of complimentary sensors is averaged generating a sinus-suppressed signal configured to substantially correlate with the thickness of the wafer layer being processed. In one embodiment, the signals generated by a set of complimentary sensors defined along a circle of a wafer carrier are averaged generating a sinus-suppressed signal significantly correlating with the thickness of the wafer layer being processed or being removed. As used herein, the term “complimentary sensors” refers to a set of two or more sensors substantially uniformly distributed along a circle of the wafer carrier such that the sinusoidal component in the average of generated sinus signals is substantially suppressed so as to precisely correlate with thickness of a wafer layer being processed.
[0044] In preferred embodiments, the sinusoidal component of the noise is eliminated by averaging the alternative phase signals generated by the plurality of complementary sensors. The term “noise,” as used herein, refers to any factor affecting the generated signals (e.g., undulating disturbance, etc.). In this manner, the suppression sinus signal can be implemented to determine the sensor signal with significantly improved signal-to-noise ratio. In one example, the plurality of sensors is eddy current sensors (ECS) sensors.
[0045] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be understood, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention.
[0046] [0046]FIG. 3A is a simplified schematic diagram of an exemplary wafer carrier 118 including a pair of complementary sensors 128 a and 128 b measuring a thickness of a layer of a wafer 122 , in accordance with one embodiment of the present invention. In one embodiment, the complementary sensors 128 a and 128 b are ECS sensors. As shown in the embodiment of FIG. 3A, the wafer carrier 118 is mounted on a carrier spindle 133 using a gimbal 134 . The gimbal 134 positioned above the wafer carrier 118 is implemented to align the wafer carrier 118 and the wafer 122 to the moving polishing pad 130 during the polishing operations. As can be seen, the gimbal 135 mounted on the carrier spindle 133 is designed to rotate in the direction of wafer rotation 134 . The carrier spindle 133 is configured to apply the wafer carrier 118 and thus the wafer 122 on to the moving polishing pad 130 .
[0047] In one example, while the wafer carrier 118 and thus the wafer 122 rotate in the rotation direction 134 , the wafer carrier 118 and the wafer 122 are applied to the polishing pad 132 with the force F. In some embodiments, despite including the gimbal 135 to align the wafer carrier 118 and the wafer 122 with a surface of the polishing pad 130 , the wafer 122 is applied to the polishing pad 130 such that initially, a leading edge 122 a of the wafer 122 digs into the polishing pad 130 . Thereafter, the center of the wafer 122 c and a trailing edge 122 b come into contact with the polishing pad 130 .
[0048] In another embodiment, the leading edge 122 a digging into the polishing pad 130 leads to a decrease in the carrier film 120 thickness close to the leading edge 122 a of the wafer. As a consequence, the standoff and thus the ECS signals being detected by the ECS sensor 128 a are modified. The wafer leading edge 122 a digging into the polishing wafer also increases the temperature at the wafer leading edge 122 a affecting the sinusoidal undulation close to the wafer leading edge 122 a . As will be described in more detail below, in one embodiment, the ECS signal detected by the ECS sensors 128 a and 128 b at the wafer leading edge 122 a and trailing edge 122 b , respectively, are implemented to suppress the ECS signal undulations.
[0049] Reference is made to FIG. 3B, depicting a simplified schematic top view of the wafer carrier 118 of FIG. 3A being applied to the polishing pad 130 , in accordance with one embodiment of the present invention. As can be seen, while the ECS sensor 128 a is defined on a radius R of a hypothetical circle 123 a defined within the wafer 122 , the complimentary ECS sensor 128 b is defined on a radius −R of the hypothetical circle 123 a . In this manner, as will be explained below, variation in signal undulation amplitude can be eliminated (i.e., eliminating any sinusoidal component of the noise) beneficially using one of the functions of sinus. As can be appreciated, the resulting suppressed sinus signal substantially correlates with the true thickness of the target layer.
[0050] [0050]FIG. 3C is a simplified schematic top view of the wafer carrier 118 of FIG. 3A showing the two ECS sensors 128 a and 128 b being defined 180 degrees out of phase to one another, in accordance with one embodiment of the present invention. That is, the signal from one sensor 128 a is offset by the signal from the other sensor 128 b . As can be seen, the ECS sensor 128 a creates an angle α with reference to an angle 0 degree 131 while the ECS sensor 128 b creates an angle 180+α with reference to the angle 0 degree 131 . As further shown, the ECS sensor 128 a is defined at the radius R as opposed to the ECS sensor 128 b that is defined at the radius −R.
[0051] In accordance with one embodiment, suppressing the variation in sinusoidal amplitude in the embodiment of FIG. 3C can further be understood as shown in Table 1 below. In one embodiment, assuming that S 0 is the true signal magnitude sinusoidally modulated by the carrier rotation. As a result, the true signal magnitude S is configured to oscillate as:
S=S 0(1+sin α)
[0052] Furthermore, the signal traces S 1 and S 2 for corresponding sensor 1 and sensor 2 located at a given circle, each located at diametrically alternative positions, also follow oscillating equations provided in Table 1. By averaging the sinus components of the signal traces S 1 and S 2 , at the same time, the true non-oscillating signal amplitude in real time can be obtained.
TABLE 1 Two-Sensor Complimentary Sinus Signal Suppression S1 = S 0(1 + sin α) S2 = S0(1 + sin (180 + α)) (S1 + S2)/2 = S0(1 + 1 + sin α + sin (180 + α))/2 (S1 + S2)/2 = S0(2 + 0)/2 (S1 + S2)/2 = S0 * 2/2 (S1 + S2)/2 = S0
[0053] Thus, as can be seen, where a pair of complementary ECS sensors is implemented, the sinusoidal signals generated by the respective sensors are synchronously recorded. The sinus components of the sinusoidal signals are then averaged in accordance with the number of sensors implemented (e.g., 2, in this example). In this manner, variation in the amplitude of the ECS sinusoidal signals is suppressed, creating a signal that is substantially unaffected by the rotational sinusoidal noise that precisely correlates with the true thickness of the processed layer.
[0054] Reference is made to the embodiment of FIG. 3D, depicting a simplified schematic top view of the wafer carrier 118 including three sets of complimentary ECS sensors built therein, in accordance with one embodiment of the present invention. As can be seen, a first set of complimentary ECS sensors 128 a and 128 a ′ are defined at radii R 1 and −R 1 , respectively. In a like manner, a second set of complimentary ECS sensors 128 b and 128 b ′ are defined at radii R 2 and −R 2 while a third set of complimentary ECS sensors 128 c and 128 c ′ are defined at radii R 3 and −R 3 . In accordance with one embodiment, the sinus component of the sinusoidal signals of each pair of complimentary ECS sensors is synchronously recorded and averaged, generating a combination sinus suppressed sinusoidal signal that significantly correlates with the thickness of the wafer layer. That is, by offsetting the sinusoidal signals between each pair of ECS sensors, the electromagnetic field produced by each pair of sensors will suppress each other. As can be appreciated, the average of each complementary pair of ECS sensors 128 a and 128 a ′, 128 b and 128 b ′, and 128 c and 128 c ′ are substantially equivalent to zero. As shown, the radius R 3 is shown to be greater than radius R 2 that in turn is greater than the radius R 1 . As will be described in more detail below, the greater the radius is, the greater the gradiance becomes. However, the embodiments of the present invention eliminate such variance in gradience by averaging the sinus component of the sinusoidal signals recorded synchronously using the complimentary ECS sensors.
[0055] Suppressing the variance in sinusoidal signal amplitude of ECS sensors are further illustrated in the graphs of signals generated by complimentary ESC sensors shown in FIG. 4, in accordance with one embodiment of the present invention. A graph 134 a plots an eddy current sensor output in volts (i.e., the y-axis 112 ) versus the time (i.e., the x-axis 110 ) as generated by the ECS sensor 128 a ′. Similarly, a graph 134 a ′ plots an eddy current sensor output in volts versus the time, as generated by the ECS sensor 128 a . A graph 134 ″ represents the average of the sinus components of the sinusoidal ESC sensor signals 128 a and 128 b . As can be appreciated, by averaging the sinus component of the sinusoidal ECS signals of the ECS sensor defined on angle α on a circle having a radius R and the ECS signal of the ECS sensor defined on angle 180+α on a radius −R, the sinus component of the noise affecting the sinusoidal signals is substantially eliminated. Thus, in this manner, the thickness of the metal layer being processed substantially correlates with the amplitude of the sinus suppressed combination signal. In one embodiment, the signal intensity is linearly related to the distance of the respective sensors 128 a and 128 a ′ from the wafer layer being processed. A change in the intensity of each signal caused by movement of the wafer layer toward the sensor 128 a is offset by a substantially opposite change in the intensity resulting from moving the wafer layer from the sensor 128 a ′. In this manner, advantageously, changes in the amplitude of the sinusoidal signals caused by the sinus component of the noise are substantially eliminated.
[0056] For instance, at the point the signals are shown to be at their lowest, the ECS sensors have substantially the least distance from the continuous metal film to be removed. Thereafter, as the thickness of the metal film becomes less, the intensity of the signals is shown to be increasing, as illustrated by graphs 134 a and 134 a ′. The increase in signal intensity continues until the metal film (e.g., copper film) is substantially completely removed from the wafer surface at which point, the sinusoidal graphs 134 a and 134 a ′ assume a more smooth path.
[0057] As can be seen, signals generated by each sensor contains a sinusoidal component illustrated in the graphs 134 a and 134 a ′, which as can be appreciated are substantially equivalent but out of phase. Thus, the average of the two sinusoidal ECS signals having equal but out of phase amplitudes, the combo graph 134 a ″, is a graph in which the sinus component of the noise has been eliminated. In this manner, the combo sinus suppressed signal can be implemented as a measure of the true thickness of the target layer (i.e., the metal film), as the sinusoidal ECS signal correlates with the thickness of the metal film. In one embodiment, the ECS sensors implemented are ECS sensors commonly available such as GP-A series analog displacement sensors available from SUNX limited.
[0058] [0058]FIG. 5A is an exploded, simplified, diagram of graphs 136 a and 136 a ′ of a pair of complementary ECS sensors, in accordance with one embodiment of the present invention. As shown, the graph 136 a represents the ECS signal from a sensor located at a radius R while the graph 136 a ′ represents the ECS signal from a sensor located 180 degrees out of phase with respect to the first sensor, defined on the radius −R. One of ordinary skill in the art can appreciate variation in signal amplitude for the graphs 136 a and 136 a ′. In accordance with one embodiment of the present invention, by implementing pairs of sensors being defined 180 degrees out of phase, the variation in signal amplitude can be eliminated substantially by simply averaging the sinus components of the two signal graphs 136 a and 136 a ′, generating a sinus suppressed graph 136 a″.
[0059] Reference is made to the exploded simplified graphs 136 a , 136 a ′, and 136 a ″ shown in FIG. 5C, in accordance with one embodiment of the present invention. As shown, both graphs 136 a and 136 a ′ are sinusoidal with varied amplitudes, with the two graphs 136 a and 136 a ′ being generated by ECS signals defined at substantially 180 degrees out of phase angles. Despite the two graphs 136 a and 136 a ′ having evident amplitude variation and undulations caused by the noise, the combo graph 136 a ″ is shown to be a sinus suppressed signal graph in which undulations caused by the noise have been eliminated. As a result, the combo graph signal 136 a ″ can be implemented to determine a true thickness of the metal film being removed.
[0060] Implementing a set of complimentary ECS sensors including a plurality of complementary ECS sensors so as to create a sinus suppressed combination graph is shown in embodiments of FIGS. 6 A- 6 H, in accordance with some embodiments of the present invention. FIG. 6A shows a carrier head 118 including a set of three complementary sensors 128 a , 128 b , and 128 c , with sensors 128 a - c being defined 120 degrees out of phase with each other. In this manner, spatial coverage of the metal film (i.e., the target layer) increases, beneficially allowing a more accurate measurement of the metal film thickness. Table 2 below provides further explanation as to suppression of sensor signals generated by exemplary triplet-sensor complimentary sensors, allowing synchronous measuring of the sensor signals and averaging of the sinus components of the sensor signals.
TABLE 2 Amplitude Suppression Implementing Three Complimentary Sensors (S1 + S2 + S3)/3 = S0 (3 + sin α + sin (α + 120) + sin (α + 240))/3 sin x + sin y = 2 sin ((x + y)/2) cos((x − y)/2) sin (α + 120°) + sin (α + 240) = 2[sin(α + 12 + α + 240)/2)][cos (α + 12 − α − 240)/2] sin (α + 120°) + sin (α + 240) = 2 [sin(2α + 360)/2)][cos (−120)/2] sin (α + 120°) + sin (α + 240) = 2 [sin(α + 180)] cos (−60) sin (α + 120°) + sin (α + 240) = 2 (−sin α)(1/2) sin (α + 120°) + sin (α + 240) = −sin α (S1 + S2 + S3)/3 = S0 (3 + sin α − sin α)/3 (S1 + S2 + S3)/3 = S0 (3)/3 (S1 + S2 + S3)/3 = S0
[0061] In a like manner, FIG. 6B shows a carrier head 118 including a set of complementary sensors consisting of four sensors 128 a , 128 b , 128 c , and 128 d with sensors 128 a - d being defined along a circle having a radius R at 90 degrees out of phase with each other, in accordance with one embodiment of the present invention. In one embodiment, this configuration can be configured to be two pairs of sensors located diametrically opposite to one another.
[0062] [0062]FIG. 6C depicts the wafer carrier 118 including five complementary sensors 128 a - 128 e defined along a circle being 72° out of phase from each other, in accordance with still another embodiment. FIG. 6D shows six complementary sensors 128 a - 128 f being defined 60° out of phase from each other, in accordance with another embodiment. FIGS. 6E and 6F depict the wafer carrier 118 including seven complementary sensors 128 a - 128 g being defined 52° out of phase with respect to each other, and eight complementary sensors 128 a - 128 h being defined 45° out of phase from one another, respectively. As was explained in more detail above, multi sets of complementary sensors can be implemented so as to create a sinus suppressed combination signal wherein the sinus component of the noise has been eliminated, providing sensor signals that substantially correlate with the metal film thickness.
[0063] Implementing multiple combinations of complimentary sensors is depicted in the embodiments of FIGS. 6G and 6H, in accordance with one embodiment. As shown in FIG. 6G, complimentary sensors 128 a - 128 i are defined 40° out of phase and along a radius R within the wafer carrier 118 while the sensors 138 a and 138 a ′ are defined 180° out of phase along a radius R′, in accordance with one embodiment. In this manner, the average of sinus components of the signals generated by the sensors 138 a and 138 a ′ defined 180° out of phase with respect to one another provides the sinus suppressed signal that substantially correlates to the thickness of the film at and around radius R′. In a like manner, the average of signals from the sensors 128 a - 128 i defined 40° out of phase with respect to one another provides the sinus suppressed signal that substantially parallels with the thickness of the film at and around radius R.
[0064] In one embodiment, temperature, pressure, or standoff gradiance becomes greater as the radius of the circle along which the sensors are defined increases. Thus, in the embodiment of FIG. 6G, due to the radius R being greater than the radius R′, the temperature, pressure, or standoff gradiance is larger. As a result, the generated sinusoidal sensor signals have a higher amplitude than the sinusoidal sensor signals generated along the radius R′.
[0065] [0065]FIG. 6H depicts a carrier head 118 including another combination of complimentary sensors, in accordance with one embodiment of the present invention. As can be seen, ten complimentary sensors 128 a - 128 j are defined along the radius R and 36° out of phase with one another. Additionally, a combination of two complimentary sensors 138 a and 138 a ′ are defined along a radius R′ and 180° out of phase with each other.
[0066] Although the embodiments of the present invention have been shown to include two through ten complementary sensors, one of ordinary skill in the art must appreciate that the embodiments of the present invention may implement any suitable combination of uniformly and equally distributed sensors defined along the same circle of the carrier head to produce sinusoidal signals substantially correlating with the wafer layer thickness. Furthermore, one must appreciate that a multiplicity of combination of the equally distributed sensors defined along respective circles can be implemented to correlate with the thickness of wafer layer at respective locations of the sensors.
[0067] Furthermore, although some embodiments of the present invention have been described with ECS sensors, the embodiments of the present invention can be implemented to suppress signals generated by any suitable type of sensor (e.g., infrared, capacitance, sonic, etc.).
[0068] For instance, the infrared sensors may be implemented to measure the temperature of the polishing belt over time. It must be appreciated by one having ordinary skill in the art that as silicon substrate is transparent to the infrared signal, the infrared signal can detect the temperature of the thin film (i.e., target layer) of the wafer being processed by the surface of the polishing pad. In one embodiment, the wafer temperature is monitored to observe temperature variation during the CMP process. In one implementation, the temperature of the wafer and the temperature of the polishing pad begin to decrease at the endpoint.
[0069] [0069]FIG. 7 is a flowchart diagram 700 depicting operations performed to determine the thickness of a metal film using a plurality of complimentary sensors, in accordance with one embodiment of the present invention. The method begins in operation 702 in which a plurality of complimentary sensors is provided. In one embodiment the plurality of sensors are ECS sensors. The plurality of complementary sensors is defined within a wafer carrier configured to hold a wafer to be processed. In one embodiment, the wafer to be processed includes a metal film. Then, a combination signal is created using signals generated by the plurality of sensors. A thickness of the metal film defined on the wafer surface is then determined using the combination signal. As described in more detail above, the sinus suppressed combination signal is substantially unaffected by the sinus component of the noise, significantly correlating with the thickness of the film layer being removed.
[0070] Reference is made to the flowchart 800 depicted in FIG. 8 illustrating method operations performed in detecting etch endpoint implementing a plurality of complementary sensors, in accordance with another embodiment of the present invention. The method begins in operation 802 in which a plurality of sensors is provided. Next, in operation 804 , a particular circle defined by the radius on a wafer carrier is defined. Thereafter, the plurality of sensors is defined along the particular radius within the wafer carrier in operation 806 , creating a set of anti-phase complimentary sensors. In one example, the sensors are complimentary so long as the sensors are uniformly distributed along the particular radius in the wafer carrier generating a significantly suppressed sine signal. For instance, the set of complementary sensors may include two sensors, each being 180 degree out of phase with respect to the other, threes sensors being 120 degrees out of phase with each other, four sensors being 90 degrees out of phase with each other, etc.
[0071] The method then continues to operation 808 in which the signals generated by each sensor in the set of complementary sensors are measured proceeding to operation 810 in which the sinus component of the generated signals are averaged, creating a combination signal. Continuing to operation 812 , an etch endpoint of a metal film defined on the wafer surface is determined using the combination signal.
[0072] It should be appreciated that although in one embodiment the wafer carrier is aligned with the polishing pad using a gimbal, the embodiments of the present invention are not limited to CMP systems including that implement a gimbal. Additionally, although the embodiments of the present invention is shown to be implemented in CMP systems including linear polishing pads, in a different embodiment, any appropriate polishing table may be implemented (e.g., rotary, etc.) Furthermore, while the embodiments of the present invention have been described in terms of a CMP process, the complimentary sensors are not limited to a CMP process. For example, the sensors can be used within any semiconductor process that removes or deposits a layer or film on a substrate, such as etch and deposition processes. The invention has been described herein in terms of several exemplary embodiments. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention. The embodiments and preferred features described above should be considered exemplary, with the invention being defined by the appended claims.
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A method for detecting a thickness of a layer of a wafer is provided. The method includes defining a particular radius of a wafer carrier configured to engage the wafer to be processed. The method also includes providing a plurality of sensors configured to create a set of complementary sensors. Further included in the method is distributing the plurality of sensors along the particular radius within the wafer carrier such that each sensor of the plurality of sensors is out of phase with an adjacent sensor by a same angle. The method also includes measuring signals generated by the plurality of sensors. Further included is averaging the signals generated by the plurality of sensors so as to generate a combination signal. The averaging is configured to remove noise from the combination signal such that the combination signal is capable of being correlated to identify the thickness of the layer.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method and assembly for inspecting painted surfaces of a vehicle body, locating and tracking defects in the painted surface, and repairing such defects if necessary.
[0002] Automotive assembly plants are comprised of numerous individual assembly processes that must each be performed accurately and efficiently in order to produce a successful vehicle. Automation has proven highly successful in improving the accuracy and efficiency of many such individual operations by reducing incidents of operator error. One particular field in which mechanical automation has the potential to provide significant improvements over human operators is in the area of Human inspection can take considerable time and is prone to error. This runs counter to the driving forces of accuracy, efficiency, and cost effectiveness that guide the modern automotive assembly plant.
[0003] An assembly process that has proven to be particularly susceptible to operator error has been automotive paint operations. Often, a finished vehicle has undergone several paint processes prior to leaving the plant. Processes such as e-coat, prime, enamel, and clear coat can be applied to the vehicle in various combinations. Defects arising during any one of these operations may result in an unsatisfactory appearance of the vehicle. Although it is often possible to repair a defect arising out of one of these operations, it can be a significant task to locate these defects quickly and accurately and take such remedial action with minimal disruption to the automotive assembly processes. Moreover, these repair operations are relatively expensive and can be ineffective.
[0004] Human inspection and flagging of such defects has left considerable room for improvements in efficiency. Often defects must be immediately addressed or flagged (marked) by the inspectors such that the vehicle may be either removed from the production line, or remedied prior to further painting processes. The inefficiencies of these operations have provided the driving force for automating the vehicle inspection and repair process. In this light, numerous automated optical inspection techniques have been developed. Although these optical techniques have proven successful in locating defects, they often provide inadequate procedures and insufficient information for remedying the defect. Often, operators are required to step in and perform remedial procedures prior to the vehicle advancing on the line. In other methods, the defect is visually marked such that operators further along the plant line must locate and address the defect. The application of automation to not only the inspection process, but also to the isolation and repair of defects, would provide considerable advancements and efficiency over these existing solutions.
[0005] One notable advancement in the field of vehicle inspection has been the use of CAD design information in conjunction with optical imaging to locate defects within the vehicle surfaces prior to paint operations. These systems can determine deviations in the structure from design data in order to insure that the surface is in proper form for paint application prior to typical spray booth operations. It would be highly desirable to advance this known technology in order to provide improvements within the paint assembly processes. In addition, it would be highly desirable to integrate this technology into an automated paint seek and repair assembly that could provide advancements in the accuracy, efficiency, and cost effectiveness of known paint operations.
SUMMARY OF THE INVENTION
[0006] It is, therefore,.an object of the present invention to provide a method and assembly for automated inspection and locating of paint defects on a vehicle. It is a further object of the present invention to provide automated paint defect repair in response to the located paint defects.
[0007] In accordance with those and the other objects of the present invention, a method of detecting and repairing paint defects on a vehicle body is provided. The method includes developing paint defect data using electronic imaging of the vehicle body. The electronic imaging is referenced with vehicle CAD data to develop three dimensional paint defect coordinates for each paint defect. The paint defect data and the paint defect coordinates are stored with reference to the vehicle body. A repair strategy is developed based upon the paint defect data and the paint defect coordinates. Finally, an automated repair is performed on the paint defects based upon the repair strategy.
[0008] Other objects and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a schematic view of an embodiment of an automated paint seek and repair system in accordance with the present invention.
[0010] [0010]FIG. 2 is a flow chart of an operation sequence of the automated paint seek and repair system shown in FIG. 1.
[0011] [0011]FIG. 3A is an illustration of the referencing electronic imaging with CAD data utilized by the present invention.
[0012] [0012]FIG. 3B is a detailed illustration of the referencing electronic imaging with CAD data illustrated in FIG. 3A, the detail illustrating a paint defect.
DETAILED DESCRIPTION
[0013] [0013]FIG. 1 illustrates a schematic view of an embodiment of an assembly for automated paint defect detection and repair on a vehicle body 10 according to the present invention. An operational sequence of the assembly for automated defect detection and repair 10 is described in FIG. 2. The assembly 10 is intended to identify and repair paint defects after a variety of paint processes. In a typical automotive paint assembly, this may constitute inspection after e-coat, prime, and final paint applications. It should be understood, however, that the assembly 10 may be widely applicable to a variety of paint application systems, including non-automotive paint application systems.
[0014] The assembly 10 includes an imaging system 12 . The imaging system 12 generates paint defect data 14 by electronically imaging the vehicle body, as generally indicated by identifier S 1 . Imaging systems 12 , such as vision scanners are well known in the automotive industry. Although it is contemplated that a variety of imaging systems 12 may be used by the present invention, one embodiment contemplates the use of an optical system, such as a vision scanner with telecentric optics. The imaging system 12 generates paint defect data 14 as it scans the vehicle body 16 . Although it is contemplated that paint defect data 14 may encompass a wide variety of paint defect attributes, in one embodiment, the paint defect data includes the size, type and location of a paint defect.
[0015] The paint defect data 14 is passed on to a vision cell controller 18 . The vision cell controller 18 receives the information from the imaging system 12 . The vision cell controller 18 references the information from the imaging system 12 with vehicle CAD data to develop three dimensional paint defect coordinates 20 for each paint defect as generally indicated by identifier 52 . The advantage of this process is that all geometric dimensions are calibrated from a CAD master coordinates and thereby provides improved accuracy over many present systems. A representation of the reference of imaging information 21 to CAD data 22 is illustrated in FIG. 3A. A detail of a paint defect is illustrated in FIG. 3B. The vision cell controller 18 provides x, y, z and surface normal data. This not only provides improved accuracy, but allows for improved defect location such that defects need not be immediately addressed, but can be accurately located any time or position later in the process as the vehicle body 16 continues down the assembly line, or is transferred to a repair station. In addition, the vision controller 18 can be utilized to sort paint defects based upon size, type and location.
[0016] The vision cell controller 18 also stores the paint defect data 14 and the paint defect coordinates 20 referenced to the vehicle body 16 as generally indicated by identifier S 3 . Referencing the paint defect coordinates 20 to the vehicle body 16 further serves to dissociate the inspection from the repair time. This distancing allows the repair to be accomplished remote from the imaging. In one embodiment, the storage is accomplished through the use of a database containing the defect table. In alternate embodiments, however, the defect data 14 can be referenced to the vehicle body 16 in a variety of fashions including, but not limited to, storage of the data within portable memory affixed to the vehicle body 16 or the sled transporting it on the assembly line. In addition, the vision cell controller 18 can be utilized as the primary interface to the operator for identification of defect locations. Further, the vision cell controller 18 can provide setup functions, and can provide calibration functions for the imaging system 12 and any robotic controls. Inspection and repair masks can be automatically generated from the CAD geometry with precise tolerances around edges and character lines. It should be understood, that it is possible for different or additional systems to be used in conjunction with the vision cell controller 18 to provide these functions as well as a variety of others. Although a single controlled system may be utilized to accomplish the present invention, the modular system described provides a solution that can be easily implemented into existing facilities and can allow for more efficient placement of equipment within a line layout.
[0017] The assembly 10 further includes a robot cell controller 24 . The robot cell controller 24 develops a repair strategy based upon the paint defect data and the paint defect coordinates as generally indicated by identifier S 4 . The repair strategy may be based on a variety of known approaches toward paint defect repair. This may include path and processing parameters, tools, and robot choice. In addition, the robot cell controller 24 can be assigned a variety of additional tasks in order to improve the operation and functionality of the assembly 10 . These additional tasks may include, but are not limited to, generating robot paths and tooling parameters, performing quality data logging, and error reporting. In addition, the robot cell controller 24 can be utilized as an operator's primary interface for repair operation, directing and controlling the robots.
[0018] The assembly 10 also includes an automated robotic repair system 26 . The automated robotic repair system 26 performs an automated repair on the paint defects based upon the repair strategy, as generally indicated by identifier S 5 . It is contemplated that the robotic repair system 26 may include a wide variety of automated robots 28 suited for the repair of a wide variety of paint defects. These automated robots 28 are envisioned to accomplish a variety of tasks including sanding and polishing the paint defect. Other treatments, particularly suited to a given size or type of paint defect are contemplated. One advantage of the present invention is that the automated robot 28 can be programmed to approach the surface of the vehicle body 16 along the normal vector to ensure even forces across the sanding pad or other tool. This provides the benefit of creating a more even treatment of the paint defect, and can be important for certain treatments such as feathering. Additionally, as mentioned, inspection and repair masks can be automatically generated from the CAD geometry with precise tolerances around edges and character lines such that the treatment of the paint defect may be specialized for a given defect. It is also envisioned, that in at least one embodiment of the present invention, the automated repair system 26 can include force feedback sensors. This also provides a greater range of control over the repair processes. The use of force feedback sensors is well known within the robotics field.
[0019] Although specific embodiments and components have been referred to in the present specification, it should be understood that a wide variety of configurations may be utilized to practice the present invention. Specifically, the imaging system 12 , the vision cell controller 18 , the robot cell controller 24 and the robotic repair system 26 need not be individual self contained systems. These components can be in any combination to form single components accomplishing some or all of their tasks. In another embodiment, centralized computer control may be utilized while retaining separate mechanical components. While particular embodiments of the invention have been shown and described, numerous variations and alternative embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.
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A method of detecting and repairing paint defects on a vehicle body ( 10 ) is provided, including developing paint defect data using electronic imaging of the vehicle body (S 1 ), referencing said electronic imaging with vehicle CAD data to develop three dimensional paint defect coordinates for each paint defect (S 2 ), storing said paint defect data and said paint defect coordinates referenced to the vehicle body (S 3 ), developing a repair strategy based upon said paint defect data and said paint defect coordinates (S 4 ), and performing an automated repair on the paint defects based upon said repair strategy (S 5 ).
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FIELD OF THE INVENTION
The present invention relates to a web cutting device including a cutter blade and an actuator which operatively acts upon the cutter blade so as to produce a cutting stroke for cutting a web.
The present invention also relates to a method for cutting a web across its width.
BACKGROUND OF THE INVENTION
In devices for treating a paper web, such as, for example, in paper machine and coating machines, cutting devices are used to cut off the web at a number of positions when any failure takes place in the operation of the machine, such as an uncontrolled web break. The function of the web cutting is to protect such items or equipment that might be damaged when the paper web proceeds through the machine in a wrinkled state and having lost its tension inside the machine, for example, through a coating station or through a calender with soft calender rolls.
Further, cutting devices are used in a reel-up of the web as a part of the machine-reel change equipment.
When the running speeds of the machines used in the manufacture and finishing of paper (for example, during coating, calendering, slitting) are increased even to levels higher than about 2500 meters per minute, requirements are imposed on the operation of the web cutting devices. These requirements are a shorter reaction time, smaller size for the device, and higher speed of movement of the blade at the moment of cutting.
The prior art paper web cutting devices have a construction in which a number of pneumatic cylinders arranged at a distance from one another operatively act upon the cutter blade of the cutting device. After cutting, the pneumatic cylinders return the cutter blade back to its initial position. However, by means of these prior art devices, the cutter blade cannot be given a sufficiently high speed, for which reason an excessively long time delay occurs in the cutting which results in an incorrect cutting point, i.e., the cutting is too inaccurate in respect of the location of the web at which cutting is desired. An excessively slow movement of the cutter blade also results in an inferior cutting result in the paper web. Thus, the prior art devices have the disadvantages of insufficient speed and inferior cutting quality.
At present, an accuracy of about 0.3 meter is commonly required from a paper web cutting device. This means that, from the cutting command, the time delay must be such that the cutting error is less than the required limit of accuracy of 0.3 m. In the prior art devices, in which a number of pneumatic cylinders placed at a distance from one another are used, the time delay is of an order of about 0.25 second. With the present-day web speeds (e.g., about 1200 meters per minute about), this corresponds to a distance of about 5 meters in the web. If an error of 10% is permitted in the cutting, it results from this that the accuracy of this prior art cutting device is just of an order of about 0.5 meter. This is higher than the desired accuracy limit and moreover, increases as the web running speed increases.
Finnish Patent Application No. 860797 describes a paper web cutting device which includes a frame part and a blade device arranged on the frame part for cutting the paper web, as well as an actuator for producing the power necessary for the blade device for cutting the paper web. The actuator for producing the power necessary for the blade device to cut off the paper web is a spring device in which cutting energy has been stored. The cutting device is provided with at least one charging device for charging the spring device. The charging devices are hoses expandable by means of compressed air or equivalent.
German Utility Model Application G-9413363.8 describes a paper web cutting device fitted to operate so that it cuts off a paper web moving in a space between two rolls over which the web runs. The cutting device includes a toothed cutter blade and an actuator arranged to bring the cutter blade, which is attached to a lever arm, into a cutting movement by the intermediate of the lever arm. The actuator can be pneumatic, hydraulic, electric, piezoelectric, magnetic or inductive.
Even though, by means of these prior art cutting devices, a quick cutting of the web is aimed at, these prior art devices involve a number of significant drawbacks. The cutting device requires an abundant space and, moreover, its operation is not very adequate in view of safety considerations and can cause risky situations, for example, for people working at paper and coating machines. A further drawback of these prior art devices is the long delay in accelerating the blade beam, i.e., the beam on which the cutting blade is mounted, to the cutting speed.
The prior art cutting devices are massive, and a large amount of power is required to produce the necessary stroke speed. Also, stopping of the massive cutter blade is problematic, and the massive cutter blade produces high dynamic loads in the cutting device, because of which, the constructions must be robust and quite large. For this reason, the prior art cutting devices are unfortunately spacious and, moreover, the high dynamic loads applied to the cutting device are also effective in the environment in direct vicinity of the cutting device.
Finnish Patent Application No. 944816 describes a web cutting device including a frame part and a blade device arranged in the frame part to perform the cutting of the web. A first frame part and a second frame part of the frame part are curved faces between which there is an annular space. At least one of the curved faces is displaceable, the cutter blade being fitted to be charged in the annular space. There is an opening for the striking opening of the cutter blade at least in one of the frame parts.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide an improvement over the prior art web cutting devices.
It is a more specific object of the present invention to provide a web cutting device and method whose cutting result is as short as possible in the direction of progress of the web.
It is a further object of the present invention to provide a web cutting device and method which is suitable both for paper web and board web and by whose means the web can be cut off at once across substantially the entire width of the web.
It is still a further object of the present invention to provide a cutting device and method which permits a cutting stroke as rapid as possible and which also permits to make the construction of the cutting device of a size as small as possible.
The objects of the present invention mentioned above, and others, are achieved by means of a cutting device including an actuator which comprises a number of cylinders placed inside a container, or alternatively of a number of cylinders placed individually in a plurality of containers. Each of the cylinders includes a piston and a piston rod coupled thereto. The piston rods are attached to an elongate cutter blade, which is adapted to extend across substantially the entire width of the web, with a certain spacing in the longitudinal direction of the cutter blade. More generally, the device for cutting a web in accordance with the invention comprises cutting means for cutting the web, and actuator means coupled to the cutting means for moving the cutting means into engagement with the web such that the cutting means cut the web. The actuator means comprise at least one container having an interior compartment fillable with a compressed fluid and a plurality of cylinders arranged inside the container(s). Each of the cylinders includes a movable piston and a piston rod coupled to the piston. The piston rods are attached to the cutting means at a distance from one another. To produce a cutting stroke, the actuator means comprise means for fluidly coupling an area above the pistons to the interior compartment such that the compressed fluid in the interior compartment of the container(s) is directed to move the pistons and the piston rods coupled thereto and thus the cutting means.
By means of the cutting device in accordance with the present invention, a number of remarkable advantages are obtained, of which the following should be mentioned. The stroke of the cutting device is very quick, and the size of the cutting device is as small as possible. By means of the cutting device, it is possible to cut off the paper or board web at once across substantially the entire width of the web so that the distance over which the web is cut is as short as possible in the direction of progress of the web. As a result thereof, the "tail" produced, for example, in connection with splicing, can be made considerably shorter than by means of the prior art cutting devices. Also, placement and fitting of the small-size cutting device in accordance with the invention in different environments is far easier than fitting of the prior art cutting devices.
With a cutting device in accordance with the present invention, a high stroke speed of about 15 meters per second of the cutter blade is achieved with a very good reproducibility. The quick stroke of the cutter blade of the cutting device is produced by means of large-area, quickly opening, pressure-controlled control valves of cylinders attached to the cutter blade as well as by preferably placing the cylinders in the interior of the pressure container so that the passage of the compressed air from the pressure container to the cylinders is as short as possible. The moving parts of the cutting device in accordance with the invention comprise the cutter blade and piston rods and pistons attached to the cutter blade with a certain spacing. The proportion of the weight of the cutter blade to the total weight of all the moving parts is optimally about 70%. Thus, the lightness of the cutter blade contributes to its rapid movement to cut the web.
The method for cutting a web in accordance with the invention comprises the steps of arranging a plurality of cylinders in at least one container having a pressurizeable interior compartment, arranging a piston and a piston rod coupled thereto in each of the cylinders, attaching each of the piston rods to a cutting blade at different locations spaced from one another along the length of the cutting blade, pressurizing the interior compartment of the container(s) with a compressed fluid, and producing a cutting stroke for cutting the web by directing the compressed fluid from the interior compartment into engagement with the pistons to cause the pistons, the piston rods coupled thereto and thus the cutting blade attached to the piston rods to move. The cylinders may be arranged in the interior compartment of the container(s) such that each of the cylinders has an open end at which a respective one of the pistons is situated, and a flow passage is formed between the interior compartment and an area behind the pistons in the cylinders into which the compressed fluid operatively flows. The flow of compressed fluid from the interior compartment into engagement with the pistons can be controlled by arranging control valves in connection with the cylinders to operatively open a passage between the interior compartment of the container(s) and an area behind the pistons. An application of pressure into the area behind the pistons causes the pistons to move and thus move the piston rods and the cutting blade attached thereto to cut the web. Opening of the passage achieved by movement of the control valves can be attained by generating a pressure difference between two sides of the control valves.
The invention will be described in detail with reference to some preferred embodiments of the invention illustrated in the figures in the accompanying drawings. The invention is, however, not confined to the illustrated embodiments alone.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings are illustrative of embodiments of the invention and are not meant to limit the scope of the invention as encompassed by the claims.
FIG. 1 is a schematic sectional view of a preferred embodiment of the cutting device in accordance with the invention which is used in the method in accordance with the invention.
FIG. 2 is a schematic sectional view of the cutter device shown in FIG. 1 in situation in which the cutter blade has carried out the cutting movement.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the accompanying drawings wherein the same reference numerals refer to the same or similar elements, in the embodiment shown in FIGS. 1 and 2, the cutting device in accordance with the invention is denoted generally by reference numeral 10. The cutting device 10 includes a cutter blade 11 and an actuator 12 which is fitted to act upon the cutter blade 11 to produce the cutting stroke. The cutter blade 11 can be elongate and adapted to extend across substantially the entire width of the web, i.e., the longitudinal direction of the cutter blade 11 is substantially coextensive with the width of the web. In this embodiment, the actuator 12 comprises a number of cylinders 13, in each of which there is a piston 14 and a piston rod 15 coupled to the piston 14. The piston rods 15 are also attached to the cutter blade 11 with a certain spacing from one another in the longitudinal direction of the cutter blade 11. The spacing of the attachment of the piston rods 15 to the cutter blade 11 depends on the number of the cylinders 13. The number of the cylinders 13 is preferably from about 6 to about 14, and a number that is recommended in particular is from about 8 to about 10, depending on the length of the cutter blade 11 in the direction transverse to the running direction of the web, i.e., its longitudinal direction. The cylinders 13 are placed in the interior of a container 17, and a pressure is present in the container 17, i.e., a compressed fluid, and is denoted by the letter P S . Each cylinder 13 can also have an individual container 17 of its own. The movement of the piston 14 is stopped by means of a stop cushion 16 or equivalent movement arresting means. The operation of the pistons 14 is controlled by means of control valves 18 or other equivalent control means coupled to respective ones of the pistons 14. The control pressure is denoted by the letter P O , and the back pressure is denoted by the letter P V . The magnitude of the control pressure P O in a control chamber 20 is preferably about 80% of the pressure P S in the container 17. Guide means for guiding the movement of the cutter blade 11 is denoted by the reference numeral 19. The piston 14 can be returned either by means of the back pressure P V effective in an area below the piston 14 (and which is greater than the pressure P S during movement of the piston 14 from the cutting position to the non-cutting position) or by passing a pressure present in a separate pipe system to the area below the piston 14 (which may also be greater than the pressure P S for the duration of the movement of the piston 14 from the cutting position to the non-cutting position) or other equivalent piston return means.
In the cutting device 10 in accordance with the invention, the control valves 18 are opened in a highly efficient manner because, when the slide of the control valve 18 starts moving, the pressure P S in the container 17 can act upon the slide of the control valve 18 on an area that is multiple (or increased) in comparison with a situation in which the control valve 18 is fully closed. In this manner, since the force of opening of the control valves 18 depends on area, i.e., force equals pressure times area, an increase in the area on which the pressure is effective increases the force moving the control valves 18 into an open position. The control valves 18 have a first surface area or portion 18a exposed to the compressed fluid in the interior compartment of the container 17 when the control valve is in a closed position and a second surface area or portion 18b which is larger than the first surface area when the control valve 18 is in an opening position. The second surface area increases as the control valve is opened. Thus, in the cutting device 10 in accordance with the invention, a rapid stroke of the cutter blade 11 is produced by means of the large-area, rapidly opening, pressure-controlled control valves 18 of the cylinders 13 attached to the cutter blade 11 as well as by preferably placing the cylinders 13 in the interior of the pressure container 17 so that the passage of the compressed air from the pressure container 17 into the cylinders 13 is as short as possible. Thus, in the cutting device 10 in accordance with the present invention, it has been successfully possible to make the cutter blade 11 and the devices that move it as of a weight as low as possible. The moving parts essentially consist of the cutter blade 11 and piston rods 15 and pistons 14 attached to the cutter blade 11 with a certain spacing. The proportion of the weight of the cutter blade 11 to the total weight of all the moving parts is optimally about 70%.
In the cutting device 10 in accordance with the invention, the operation of the control valves 18 has been made very accurate, and the speed of opening of the control valves 18 is very high. This has been achieved by reducing the weight of the slide in the control valve 18 and the proportions of the areas so that the control valve 18 is opened with a very high control pressure P O , preferably with a pressure that is of an order of from about 2.3 to about 7 bar if the pressure P S in the container 17 is of an order of from about 3 to about 10 bar. The control valve 18 is caused to open by a specific difference between pressures P S and P O , i.e., when pressure P O is less than pressure of P S to a certain extent, control valve 18 will be forced upward opening a passage 22 to direct the pressure P S to act on piston 14, on an area which is continually increasing as the control valves 18 open. In other words, the compressed fluid will flow through passage 22 into an area or chamber 14a above the piston 14 (in the illustrated embodiment) and force the piston downward. This passage 22 constitutes means for fluidly coupling the chamber 14a above the pistons 14 to the interior compartment. Preferably, the pressure P S in the container 17 is about 4 bar. The high level of the control pressure P O , makes the operation of the control valve 18 very accurate, because the discharging of the control valve 18 takes place so that the control pressure P O of the control valve 18 is eliminated substantially at the same time from all the control chambers 20. The more rapidly the pressure P O in the control chambers 20 is lowered, the more quickly is the pressure range bypassed in which all the control valves 18 are opened, i.e., the required difference between pressures P S and P O . The pressure level has a substantial effect on the speed of lowering of pressure.
With a cutting device in accordance with the present invention, a high stroke speed of about 15 meters per second of the cutter blade 11 is achieved with a very good reproducibility. For this reason, by means of the cutting device 10 in accordance with the invention, it is possible to cut off the web at once across the entire width of the web so that the cutting result in as short as possible in the direction of progress of the web, and thus, the "tail" produced, for example, in connection with splicing operations can be made considerably shorter than by means of the prior art cutting devices. The cutting device 10 in accordance with the invention is also of small size, so that its fitting in different environments is very easy.
From the point of view of the speed of the cutter blade 11 of the cutting device 10 in accordance with the invention, it is important that the cylinders 13 should operate at the same time, i.e., in a synchronized manner. Also, in view of the service life of the blade 11, it is important that the pistons 14 collide against their stop cushions 16 as precisely at the same time as possible. The timing can be affected by means of regulation of the flow resistances in the system of control pressure pipes 21 in flow communication with the control chambers 20. For this reason, the control pressure pipes 21 of all the control valves 18 should preferably be made equally long, and the control pipes should be provided with an equal number of elbows, i.e., to provide equal length paths. All the cylinders 13 of the cutting device 10 in accordance with the invention can be easily made to operate within one millisecond. During one millisecond, the piston 14 proceeds a distance of about 1 mm from its starting point. This maximal phase difference is, in fact, theoretical, for the rigidity of the cutter blade 11 in the direction of the force of the piston 14 is high enough so that the cutter blade 11 can equalize differences of this magnitude.
The examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims.
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A web cutting device for cutting a web in which a an actuator acts upon a cutter blade so as to produce the cutting stroke. The actuator includes several cylinders placed inside a container or alternatively a number of cylinders placed individually in a plurality of containers. Each of the cylinders includes a piston and a piston rod, the piston rods being attached to the cutter blade with a certain spacing along the length of the cutter blade in a direction transverse to the running direction of the web.
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BACKGROUND
1. Field of the Invention
The present invention relates generally to compositions for chemical mechanical planarization, particularly to compositions for chemical mechanical planarization of tantalum and tantalum nitride layers as occur in the manufacture of integrated circuits.
2. Description of Related Art
Modern integrated circuits typically comprise millions of active devices on a single substrate, electrically interconnected through the use of single and multilevel interconnections including conductive lines and plugs (“vias”). Conventionally, integrated circuits include a semiconductor substrate and a plurality of sequentially formed dielectric layers and conductive patterns, including conductive lines, vias and interconnects. Typically, the conductive patterns on different layers, i.e., upper and lower layers, are electrically connected by a conductive interconnect or plug filling a via opening through the interlayer dielectric (“ILD”), while a conductive plug filling a contact opening establishes electrical contact with an active region on a semiconductor substrate, such as a source/drain region. As is known in the art, a damascene technique can be employed to form interconnects by forming an opening or channel in the ILD and filling the opening with a conductive material, typically a metal. The metal typically fills the channel in the ILD and covers the field region atop the ILD between channels. Planarization typically is the next step, removing the metal in the field region, removing barrier/adhesion layers (if any), and providing a substantially planar surface for further coating and patterning.
A dual damascene technique is also known in the art and can be employed to form conductive plugs and lines simultaneously. Basically, dual damascene involves forming an opening comprising a lower contact or via opening section in communication with an upper channel section, and filling the opening and channel section with a conductive material, typically a metal, to simultaneously form an electrically connected conductive plug and channel combination. Planarization follows, to remove metal and other materials as in the damascene technique.
Elemental aluminum and its alloys have been traditionally employed for filling metallic channels and vias in the fabrication of integrated circuits having relatively low integration density. The advantages of aluminum include its low resistivity, superior adhesion to typical dielectric layers (SiO 2 ), ease of patterning, and high purity.
However, aluminum and aluminum alloys are susceptible to detrimental increases in contact resistances during high temperature processing. Another problem associated with the use of aluminum and aluminum alloys in integrated circuits is electromigration, which becomes a more serious concern as the level of integration and the density of components increase. The higher number of circuit components in very large-scale integration (“VLSI”), ultra large-scale integration, (“ULSI”) and even higher densities, requires the use of conductive interconnects with smaller cross sections. This causes higher electrical resistance in the interconnect and heat generation. Accordingly, as integrated circuit patterning schemes continue to miniaturize to submicron dimensions, aluminum based metallurgies have become increasingly marginal for handling the increased circuit speed and current density requirements. Materials having higher conductivity than aluminum or its alloys would be advantageous as interconnects. Hence, the escalating requirements for high density and performance associated with VLSI, ULSI and beyond require responsive changes in multilevel interconnection technology.
Currently, copper and copper alloys deposited on a tantalum (Ta) and/or tantalum nitride (TaN) adhesion/barrier layer are receiving considerable attention as replacement materials for, inter alia, aluminum and aluminum alloys in VLSI and ULSI multilevel metallization systems. Copper has a lower resistivity than aluminum, and also significantly higher resistance to electromigration. However, problems with integrating copper metal into multilevel metallization systems include the difficulty of etching copper and its relatively high diffusivity. Since copper is difficult to pattern precisely and economically, damascene or dual damascene processing is typically preferred over subtractive processes for creating copper interconnections. To hinder copper diffusion and to enhance its adhesion, barrier/adhesion layers (typically Ta/TaN) are used to separate the copper interconnections from the surrounding dielectric and to enhance the adhesion of the copper. However, these multicomponent layered structures of Cu/Ta/TaN/ILD exacerbate the problems of providing smooth surfaces for accurate patterning, while accurate patterning is increasingly necessary for providing reliable electrical contact to submicron features.
Chemical Mechanical Planarization (also referred to as Chemical Mechanical Polishing), or CMP, is the process of removing material and forming a substantially planar layer before additional layers are deposited and/or additional patterning occurs. CMP of copper and copper alloys deposited on a tantalum (Ta) and/or tantalum nitride (TaN) barrier/adhesion layer has become the subject of considerable interest. For economy of language, we refer to copper and/or copper alloys as “copper” and barrier/adhesion layer(s) as “barrier layer,” understanding thereby that the copper conductor may include copper alloys (among other materials) and the barrier layer may have adhesive as well as barrier functions. Slurries previously employed in the CMP processes of copper layers, barrier layers and/or insulating layers have suffered from several disadvantages, including an inadequate selectivity between removal rates of copper, barrier and insulating materials. The selectivity in the removal of copper and barrier materials should be neither too high nor too low. Uncontrollable removal rates can be the undesirable result. Over-polishing of some materials in order to remove other materials may also occur when selectivity is too high. Over-polishing can lead to significant degradation, dishing or erosion of the surface being over-polished and consequently poor planarization.
Furthermore, current polishing slurries employed in these CMP processes have suffered from poor nonuniformity values. Nonuniformity is a known way to quantify the uniformity of material removal rate on many points over a wafer. For example, pre-CMP thickness measurements are typically taken by measuring selected points on each wafer and then, post-CMP thickness measurements are taken at the same points. Nonuniformity is then calculated from the following formula:
Nonuniformity(“NU”)%=100 [σ(Δ i )/ave(Δ i )] Eq. 1.
Where Δ i =thickness of the material removed from point i on the wafer.
σ(Δ i )=standard deviation of all Δ i values on the wafer.
ave(Δ i )=mean of all Δ i values on the wafer.
The set of Δ i 's are equal to the thickness removed or the pre-CMP thickness minus the post-CMP thickness for each of the measured points, i. Typically, good nonuniformity values are less than 5% for CMP of conductors. CMP of barrier layers is considered acceptable if NU values less than about 23% are achieved.
For the foregoing reasons, among others, there is a need for CMP slurry compositions that, inter alia, planarize or polish copper and Ta and/or TaN barrier layers at desirable high polishing rates while minimizing surface imperfections, defects, corrosion, dishing and erosion. Particularly, there is a need for one or more CMP slurry compositions that provide good selectivity between copper and barrier removal rates while providing good nonuniformity values. Additionally, there is a need for one or more CMP slurry compositions that provide a high copper removal rate and a low Ta and/or TaN barrier removal rate while avoiding significant degradation, dishing or erosion. Thus, ideally, there is a need for a “phase-one” or a first chemical mechanical planarization or polishing slurry for use in connection with copper damascene or dual damascene processes that removes the copper from the field region between the copper-containing interconnects and stops planarizing when the barrier layer is reached. The phase-one CMP slurry is the subject of a patent application entitled “Compositions for Chemical Mechanical Planarization of Copper” by the same inventors as herein and co-filed herewith.
We refer to wafers having copper deposited thereon as in a damascene or dual damascene process as “copper wafers,” understanding that excess field region copper is to be removed by the CMP process. Following removal of the field region copper and exposure of the barrier layer in the phase-one CMP process, the barrier layer is then removed to complete the planarization. Different processing conditions and/or different CMP compositions are typically employed for the removal of the barrier layer. The removal of the barrier layer or the “phase-two” CMP process is the general subject of the present invention
We consider two general classes of CMP processes for the polishing of copper wafers. The first process employs a copper single-step slurry process involving a single chemical composition of the CMP slurry throughout the planarization that removes both the copper and barrier materials. This first CMP process is typically continuous, but polishing steps can be divided into as many sub-steps as needed by varying polishing pressure, speeds and other processing parameters. In general, a CMP processing step employing high polishing pressure can remove copper topography and planarize the surface efficiently. Subsequently, a step is employed using lower polishing pressure to remove the remaining copper substantially uniformly and continuing to remove barrier layer (tantalum/tantalum nitride or tungsten (W), among others) with a lower removal rate.
The second general class of CMP processes involves a phase-one and phase-two copper CMP process including two separate polishing steps using two separate polishing slurry compositions. Phase-one slurry (or the first CMP step), typically containing oxidizer and abrasive, is designed to planarize copper topography quickly and then continue to remove the copper metal, reaching the barrier layer, while maintaining good uniformity. In the phase-two step, a slurry with an oxidizer is typically used to remove the barrier layer (TaN or Ta).
The present invention is directed to a phase-two or a chemical mechanical planarization or polishing slurry that is able to selectively polish the Ta/TaN adhesion/barrier layer following removal of the copper portion in the phase-one CMP process.
The present invention relates to compositions for the chemical mechanical planarization (“CMP”) of adhesion/barrier layers, particularly Ta/TaN adhesion barrier layers overlying dielectric materials as occur in the fabrication of integrated circuits. Various CMP compositions including an abrasive, at least one oxidizer and at least one nitrate are shown to give good CMP selectivity between Ta and the dielectric as well as good CMP selectivity between TaN and the dielectric. CPM compositions pursuant to various embodiments of the present invention include high planarization rates of Ta and TaN with reduced dishing and erosion. Good nonumiformity values are also demonstrated. CMP compositions comprise an aqueous solution of oxidizer and colloidal silica abrasive. Oxidizers include hydroxylamine nitrate, nitric acid, benzotriazole, ammonium nitrate, aluminum nitrate, hydrazine and mixtures thereof in aqueous solution.
DESCRIPTION OF THE DRAWINGS
This application has no drawings.
DETAILED DESCRIPTION
The phase-two polishing slurries described herein are employed for the removal of Ta/TaN adhesion/barrier layers following removal of field region copper. As the Ta/TaN layers directly contact the ILD layer, good selectivity between Ta/TaN removal and ILD removal is advantageous for phase-two processes.
The present invention ameliorates or overcomes one or more of the shortcomings of the prior art by providing CMP slurry compositions that have one or more of the following characteristics: 1) Having an improved Ta/ILD and/or TaN/ILD selectivity. 2) Having a low removal rate for the ILD. 3) Having the ability to planarize the Ta/TaN layer at desired high planarization rates while reducing Ta/TaN dishing and erosion. 4) Having good nonuniformity values (less than about 23%).
In some embodiments, the present invention provides a phase-two chemical mechanical planarization slurry that is able to selectively planarize the Ta/TaN portion of a copper and tantalum and/or a tantalum nitride layer. In some embodiments of the present invention, the phase-two chemical mechanical planarization slurry includes an oxidizer, one or more nitrates and at least one abrasive. Some embodiments include nitrates that also function as the oxidizer. That is, the oxidizer may, but need not, be a distinct chemical species from the nitrate. However, for economy of language we typically refer to the oxidizer and the nitrate, understanding throughout that they are not necessarily distinct chemical species.
One of the nitrate compositions pursuant to some embodiments of the present invention is in the form of hydroxylamine nitrate (NH 2 OH.HNO 3 , “HAN”). HAN serves as a mild oxidizing agent, having a pH of about 2.1 to about 3.2 and includes a nitrate anion that provides good removal rate controllability of the tantalum and/or tantalum nitride barrier patterned with copper (for example). Additionally, the pH of the HAN can be adjusted by adding various types of acid, including nitric acid and/or any other inorganic acid that is chemically compatible with HAN. The HAN pH can also be adjusted by the addition of various nitrates including ammonium nitrate, aluminum nitrate, or other soluble inorganic or organic nitrate salts that are chemically compatible with HAN, and mixtures thereof.
Hydroxylamine nitrate is employed to control the rate at which the barrier layer is planarized. That is, increasing the concentration of HAN in the CMP slurry typically results in higher TaN removal rate while having no significant effect on the Cu removal rate. This tends to increase the selectivity of Cu removal with respect to TaN. HAN may be combined with other nitrates (including ammonium nitrate, aluminum nitrate, or other soluble inorganic or organic nitrate salts that are chemically compatible with HAN and mixtures thereof) and/or acids (nitric, and/or any other inorganic acid that is chemically compatible with HAN) to obtain advantageous barrier removal rates, uniformity and selectivity. Aluminum nitrate, anmonium nitrate and nitric acid may all be used to modify the pH of the CMP slurry containing HAN such that acidic conditions are maintained and, thus, function as oxidizers.
Furthermore, and pursuant to some embodiments of the present invention, the phase-two CMP slurries may include benzotriazole (aziminobenzene, C 6 H 4 NHN 2 , “BTA”). Benzotriazole is typically employed as a corrosion inhibitor for controlling the chemical etching of metal conductors, lines and interconnects (e.g copper).
The CMP phase-two slurry compositions for Ta/TaN barrier removal and polishing are delineated in detail as follows.
Phase-Two CMP Slurry Compositions
In some embodiments, the present invention includes an oxidizer and an abrasive composition.
Oxidizers
Oxidizer Components (“Oxidizer A”)
One oxidizer (“Oxidizer A”) pursuant to some embodiments of the present invention includes hydroxylamine nitrate, nitric acid and distilled or de-ionized water (collectively referred to herein as “DI water”). One example of approximate component concentrations for Oxidizer A is shown in Table A x .
TABLE A x
Typical composition for Oxidizer A:
Component Concentration
Component
(Weight Percent)
Hydroxylamine Nitrate (@ 82% solution)
3.0%
Nitric Acid (@ 28% solution)
0.08%
DI water
96.92%
pH Range
Oxidizer A is advantageously adjusted to have a pH range from about 2.6 to about 2.7 by the addition of an appropriate amount of acid as described above.
Oxidizer Components (“Oxidizer B”)
Another oxidizer (“Oxidizer B”) pursuant to some embodiments of the present invention includes hydroxylamine nitrate, benzotriazole, nitric acid and DI water. One example of approximate component concentrations for Oxidizer B is shown in Table B X .
TABLE B x
Typical composition for Oxidizer B:
Component Concentration
Component
(Weight Percent)
Hydroxylamine nitrate (@ 82% solution)
1.2%
Benzotriazole (@ 0.2% solution)
8.0%
Nitric acid (@ 28% solution)
0.024%
DI water
90.776%
pH Range
Oxidizer B is advantageously adjusted to have a pH range from about 2.8 to about 2.9 by the addition of an appropriate amount of acid as described above.
Oxidizer Components (“Oxidizer C”)
Another oxidizer (“Oxidizer C”) according to some embodiments of the present invention includes ammonium nitrate (NH 4 NO 3 ), benzotriazole and DI water. One example of approximate component concentrations for Oxidizer C is shown in Table C x .
TABLE C x
Typical composition for Oxidizer C:
Component Concentration
Component
(Weight Percent)
Ammonium Nitrate (solid)
6.0%
Benzotriazole (@ 0.2% solution)
0.6%
DI water
93.4%
pH Range
Oxidizer C is advantageously adjusted to have a pH range from about 5.1 to about 5.5 by the addition of an appropriate amount of acid as described above.
Oxidizer Components (“Oxidizer D”)
Another oxidizer (“Oxidizer D”) according to some embodiments of the present invention includes aluminum nitrate [Al(NO 3 ) 3 ] and DI water. One example of approximate component concentrations for Oxidizer D is shown in Table D x .
TABLE D x
Typical composition for Oxidizer D:
Component Concentration
Component
(Weight Percent)
Aluminum Nitrate (solid)
6.0%
DI Water
94%
pH Range
Oxidizer D is advantageously adjusted to have a pH range from about 5.1 to about 5.5 by the addition of an appropriate amount of acid as described above.
Oxidizer Components (“Oxidizer E”)
Another oxidizer (“Oxidizer E”) according to some embodiments of the present invention includes hydrazine, benzotriazole, ammonium nitrate and DI water. The present Phase-two CMP slurry compositions may be used following a phase-one CMP employing hydrogen peroxide H 2 O 2 . Typically, when hydrogen peroxide is a component of a phase-one slurry, a reside of the hydrogen peroxide remains on the surface of the wafer after polishing that can cause excessive dishing and erosion. Hydrazine-containing oxidizers ameliorate these problems associated with the presence of hydrogen peroxide.
One example of approximate component concentrations for Oxidizer E is shown in Table E x .
TABLE E x
Typical composition for Oxidizer E
Component Concentration
Component
(Weight Percent)
Ammonium Nitrate (solid)
3.0%
Benzotriazole (@ 0.2% solution)
0.006%
Hydrazine Solution NH 2 NH 2 ·H 2 O
0.5%
DI water
96.494%
pH Range
Oxidizer E is advantageously adjusted to have a pH range from about 5.7 to about 6.5 by the addition of an appropriate amount of acid as described above.
Abrasives
Abrasive Components (“Abrasive A”)
One abrasive (“Abrasive A”) according to some embodiments of the present invention comprises colloidal silica. One advantage of using colloidal silica as an abrasive in the phase-two planarization process is that the colloidal silica can serve a dual function: as an abrasive and also as a built-in buffer leading to an oxide buffing action simultaneously with the CMP. Thus, in some cases in might be possible to eliminate a third polishing step to buff the oxide in lieu of the simultaneous polishing occurring through CMP containing a colloidal silica abrasive. An example of Abrasive A is shown in the Table A a .
TABLE A a
Typical Composition for Abrasive A
Type
Colloidal silica
Concentration Weight Percent
33.5-25%
Particle Size (range)
20-150 nanometers
Particle Size (average)
71-73 nanometers
Commercial Source
Dupont: DP106
In one embodiment, Abrasive A can be of the type which is manufactured by Dupont and sold under the name, DP 106 and further processed (milled and filtered) by EKC Technology, Inc. and sold thereby under the name, MicroPlanar™ CMP9000™. The colloidal silica, in this example, has a particle size having a range between about 20 and 150 nanometers and includes an average particle size having a range between about 71 to 73 nanometers. A Material Safety Data Sheet for MicroPlanar™ CMP9000™ is attached hereto and incorporated herein.
pH Ranges
The processed silica has a pH range from about 8.1 to about 8.5.
Abrasive Components (“Abrasive B”)
Another abrasive composition (“Abrasive B”) according to some embodiments of the present invention comprises colloidal silica with different particle sizes than Abrasive A. One example of Abrasive B is shown in Table B a .
TABLE B a
Typical Composition for Abrasive B
Type
Colloidal Silica
Concentration Weight Percent
20 wt. %
Particle Size (range)
40-150 nanometers
Particle Size (average)
60 nanometers
Source
DP106
In one embodiment, Abrasive B can be of the type that is manufactured by DuPont and sold under the name, DP106 and further processed by EKC Technology, Inc. and sold thereby under the name, MicroPlanar™ CMP9003™. The colloidal silica in Abrasive B has a particle size having a range between about 40 and about 150 nanometers and includes an average particle size of approximately 60 nanometers. A Material Safety Data Sheet for MicroPlanar™ CMP9003™ is attached hereto and incorporated herein.
Barrier/Adhesion Layer CMP Slurry Compositions
Phase-Two CMP Slurry Composition (“Slurry 1 Composition”)
Some embodiments of the present invention comprise Oxidizer A and Abrasive A mixed to form a Slurry 1 Composition. In one example, and according to some embodiments of the present invention, the mixing ratio, process and removal rate data for the Slurry 1 Composition is shown in the Table 1.
TABLE 1
Slurry 1 Composition: Mixing Ratio, Process and Removal Rate
Removal Rate (Å/min)
Mixing Ratio
Process
Cu
NU %
TaN
NU %
ILD
NU %
90% Oxidizer A
3/0/70/81
921
13.8%
359
15.75%
127
24.7%
10% Abrasive A
In Table 1, the Slurry 1 Composition is comprised of 10% of Abrasive A and 90% of Oxidizer A. The process delineated with respect to the Slurry 1 Composition is achieved by applying 3 psi down force pressure, 0 psi back pressure, 70 rpm table speed (22.5 inch diameter) and 81 rpm carrier speed (8 inch diameter). The Slurry 1 Composition, when employed according to the above process, provides a Cu:TaN selectivity of approximately 2.56 (removal rate of Cu divided by the removal rate of TaN) and a copper nonuniformity (NU%) of approximately 13.8%. The Slurry 1 Composition provides a TaN:ILD selectivity of approximately 2.83, a TaN nonuniformity of approximately 15.75% and an ILD nonuniformity of approximately 24.7%.
Phase-Two Slurry Composition (“Slurry 2 Composition”)
Other embodiments of the present invention include Oxidizer B and Abrasive A mixed to form a Slurry 2 Composition. In one example, and according to some embodiments of the present invention, the mixing ratio, process and removal rate data for the Slurry 2 Composition is shown in Table 2.
TABLE 2
Slurry 2 Composition: Mixing Ratio, Process and Removal Rate
Removal Rate (Å/min)
Mixing Ratio
Process
Cu
NU %
TaN
NU %
ILD
NU %
50% Oxidizer B
1.8/0/75/75
982
10.9%
1200
9.3%
300
12.7%
15% Abrasive A
35% DI Water
In Table 2, the Slurry 2 Composition is comprised of 15% of Abrasive A and 50% of Oxidizer B and 35% DI water. The process delineated with respect to the Slurry 2 Composition is achieved by applying 1.8 psi down force pressure, 0 psi back pressure, 75 rpm table speed (22.5 inch diameter) and 75 rpm carrier speed (8 inch diameter). The Slurry 2 Composition, when employed according to the above process, provides a Cu:TaN selectivity of approximately 0.82 and a copper nonuniformity (NU%) of approximately 10.9%. The Slurry 2 Composition provides a TaN:ILD selectivity of approximately 4, a TaN nonuniformity of approximately 9.30% and an ILD nonuniformity of approximately 12.7%.
Phase-Two Slurry Composition (“Slurry 3 Composition”)
Other embodiments of the present invention include Oxidizer C, Abrasive A and DI water mixed to form a Slurry 3 Composition. In one example, and according to some embodiments of the present invention, the mixing ratio, process and removal rate data for the Slurry 3 Composition is shown in Table 3.
TABLE 3
Slurry 3 Composition: Mixing Ratio, Process and Removal Rate
Removal Rate (Å/min)
Mixing Ratio
Process
Cu
NU %
TaN
NU %
ILD
NU %
50% Oxidizer C
1.8/0/75/75
248
23.0%
650
15%
200
20%
10% Abrasive A
40% DI Water
In Table 3, the Slurry 3 Composition is comprised of 10% of Abrasive A, 50% of Oxidizer C and 40% DI water. The process delineated with respect to the Slurry 3 Composition is achieved by applying 1.8 psi down force pressure, 0 psi back pressure, 75 rpm table speed (22.5 inch diameter) and 75 rpm carrier speed (8 inch diameter). The Slurry 3 Composition, when employed according to the above process, provides a Cu:TaN selectivity of approximately 0.38 and a copper nonuniformity (NU%) of approximately 23.0%. The Slurry 3 Composition provides a TaN:ILD selectivity of approximately 3.25, a TaN nonuniformity of approximately 15% and an ILD nonuniformity of approximately 20%.
Phase-Two CMP Slurry Composition (“Slurry 4 Composition”)
Some embodiments of the present invention include Oxidizer C, Abrasive A and DI water mixed to form a Slurry 4 Composition. In one example, and according to some embodiments of the present invention, the mixing ratio, process and removal rate data for the Slurry 4 Composition is shown in the Table 4.
TABLE 4
Slurry 4 Composition: Mixing Ratio, Process and Removal Rate
Removal Rate (Å/min)
Mixing Ratio
Process
Cu
NU %
TaN
NU %
ILD
NU %
30% Oxidizer C
3/0/60/60
605
17%
1000
10%
884
15%
20% Abrasive A
50% DI Water
In Table 4, the Slurry 4 Composition is comprised of 20% of Abrasive A and 30% of Oxidizer C and DI water. The process delineated with respect to the Slurry 4 Composition is achieved by applying 3 psi down force pressure, 0 psi back pressure, 60 rpm table speed (22.5 inch diameter) and 60 rpm carrier speed (8 inch diameter). The Slurry 4 Composition, when employed according to the above process, provides a Cu:TaN selectivity of approximately 0.61 and a copper nonuniformity (NU%) of approximately 17%. The Slurry 4 Composition provides a TaN:ILD selectivity of approximately 1.13, a TaN nonuniformity of approximately 10% and an ILD nonuniformity of approximately 15%.
Phase-Two Slurry Composition (“Slurry 5 Composition”)
Other embodiments of the present invention include Oxidizer D, Abrasive A and DI water mixed to form a Slurry 5 Composition. In one example, and according to some embodiments of the present invention, the mixing ratio, process and removal rate data for the Slurry 5 Composition is shown in Table 5.
TABLE 5
Slurry 5 Composition: Mixing Ratio, Process and Removal Rate
Removal Rate (Å/min)
Mixing Ratio
Process
Cu
NU %
TaN
NU %
ILD
NU %
50% Oxidizer D
1.8/0/75/75
253
22.4%
525
25.7%
200
12.7%
10% Abrasive A
40% DI Water
In Table 5, the Slurry 5 Composition is comprised of 10% of Abrasive A, 50% of Oxidizer D and 40% DI water. The process delineated with respect to the Slurry 5 Composition is achieved by applying 1.8 psi down force pressure, 0 psi back pressure, 75 rpm table speed (22.5 inch diameter) and 75 rpm carrier speed (8 inch diameter). The Slurry 5 Composition, when employed according to the above process, provides a Cu:TaN selectivity of approximately 0.48 and a copper nonuniformity of approximately 22.4%. The Slurry 5 Composition provides a TaN:ILD selectivity of approximately 2.6, a TaN nonuniformity of approximately 25.7% and an ILD nonuniformity of approximately 12.7%.
Phase-Two Slurry Composition (“Slurry 6 Composition”)
Other embodiments of the present invention include Oxidizer E, Abrasive B and DI water mixed to form a Slurry 6 Composition. In one example, and according to some embodiments of the present invention, the mixing ratio, process and removal rate data for the Slurry 6 Composition is shown in Table 6.
TABLE 6
Slurry 6 Composition: Mixing Ratio, Process and Removal Rate
Mean Removal
Copper Patterned Wafer
Rate (A/min)
Dishing
Erosion
Mixing Ratio
pH
Cu
TaN
(Angstroms)
(Angstroms)
37.4% Oxidizer E
5.1-5.5
186
1100
600
389
17% Abrasive B
45.6% DI water
In Table 6, the Slurry 6 Composition is comprised of 17% of Abrasive B, 34.7% of Oxidizer E and 45.6% DI water. The Slurry 6 Composition, when employed according to the above process, provides a Cu:TaN selectivity of approximately 0.169. The process delineated with respect to the Slurry 6 Composition is achieved by applying 2.0 psi down force pressure, 0 psi back pressure, 70 rpm table speed (22.5 inch diameter) and 75 rpm carrier speed (8 inch diameter).
Table 6 further shows a performance difference between the Slurry 6 Composition and a current commercial phase II slurry comprising an oxidizer and an abrasive sold by EKC Technology, Inc. under the respective names of, MicroPlanar™ CMP9011™ (oxidizer) and MicroPlanar™ CMP9003™ (abrasive). As is shown in the above table, the Slurry 6 Composition reduces dishing to approximately 600 angstroms and also reduces erosion to approximately 389 angstroms.
Phase-Two Slurry Composition (“Slurry 7 Composition”)
Other embodiments of the present invention include Oxidizer B, Abrasive B and DI water mixed to form a Slurry 7 Composition. In one example, and according to some embodiments of the present invention, the mixing ratio, process and removal rate data for the Slurry 7 Composition is shown in Table 7.
TABLE 7
Slurry 7 Composition: Mixing Ratio, Process and Removal Rate
Removal Rate (A/min)
Mixing Ratio
Process
Cu
TaN
ILD
50% Oxidizer B
3/0/70/75
276
1444
120
25% Abrasive B
25% DI water
In Table 7, the Slurry 7 Composition is comprised of 25% of Abrasive B, 50% of Oxidizer B and 25% DI water. The process delineated with respect to the Slurry 7 Composition is achieved by applying 3 psi down force pressure, 0 psi back pressure, 70 rpm table speed (22.5 inch diameter) and 75 rpm carrier speed (8 inch diameter). The Slurry 7 Composition, when employed according to the above process, provides a Cu:TaN selectivity of approximately 0.20 and a TaN:ILD selectivity of approximately 12.
Having described the invention in detail, those skilled in the art will appreciate that, given the present disclosure, modifications may be made to the invention without departing from the spirit of the inventive concept described herein. Therefore, it is not intended that the scope of the invention be limited to the specific embodiments illustrated and described.
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The present invention relates to compositions for the chemical mechanical planarization (“CMP”) of barrier/adhesion layers, particularly Ta/TaN barrier/adhesion layers as occur in the manufacture of integrated circuits. CMP compositions comprise an aqueous solution of oxidizer and colloidal silica abrasive. Oxidizers include hydroxylamine nitrate, nitric acid, benzotriazole, ammonium nitrate, aluminum nitrate, hydrazine and mixtures thereof in aqueous solution.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 815,676 filed July 14, 1977, now abandoned which is a division of application Ser. No. 684,725 filed May 10, 1976 now U.S. Pat. No. 4,058,885.
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for the locating of a work member supporting fixture on a support table for the clamping of the fixture in located position on the table, especially for the machining of various regions of the work member and most especially in such a manner that even heavy work members and fixtures can readily be moved about in a machine tool into various machining positions.
The machining of work members of any substantial size in most machine tools involves time consuming, laborious repositioning of the work member in the machine tool as various regions of the work member, other than, for example, concentric portions thereof, are to be machined. When the work members being machined reach substantial size, it becomes necessary to use hoists and other power devices for elevating and moving the work members about and for lowering the work members into the proper positions for the machining of respective regions of the work member.
Such moving about of work members is, as mentioned, time consuming and laborious and can be attended with some danger. Further, the precise positioning of the work member in a selected position under such conditions is difficult and cannot always be achieved with the desired accuracy.
The present invention has as a primary objective the provision of an apparatus for use in respect of the moving and locating of work members, particularly heavy work members, and especially in machine tools, in which the moving about of the work member can be accomplished relatively easily without the use of power equipment and whereby the work member can be accurately located in respective machining positions and all being accomplished in a minimum amount of time.
BRIEF SUMMARY OF THE INVENTION
According to the present invention, a table is provided in a machine tool which may be a table member resting on a machine tool bed or which may be a table member incorporated in the machine tool construction. In any case, the table has a substantially horizontal upwardly facing surface for supporting work members to be machined.
According to the present invention, work members to be machined are mounted in fixtures provided with suitable means for securing work members in place therein with each fixture having a downwardly facing horizontal bottom surface adapted to rest on the upper surface of the table.
The table according to the present invention is provided with fluid pressure passages therein and a plurality of outlet connections in distributed relation in respect of the upper surface of the table extend from the fluid pressure passages upwardly through the top surface of the table. Advantageously, each connection has a normally closed valve at the upper end, each of which has an actuating portion protruding upwardly to above the level of the table so that, when a fixture is set on the table, the valves therebeneath will be opened and a fluid pressure film will be established between the fixture and the table which will provide for substantially friction free movement of the fixture on the table. Advantageously, the fluid under pressure is air which is readily available in most locations where machine tools are employed.
The table may be formed with T slots therein similar to what is provided in a great many machine tool beds and clamp members slidable in the slots are provided which are engageable with the fixture in adjusted positions thereof for clamping the fixture fixedly to the table.
It is advantageous for the table to have a main pivot element, such as a pin projecting upwardly therefrom, which may be in the region of about the middle of the table, and which is receivable in a socket in the bottom of the fixture resting on the table.
The fixture, in this case, is constrained to move circularly on the bed. In one modification, the socket in the fixture is replaced by a slot, and in this case, the fixture is not only rotatable on the bed but is translatable thereon in desired directions.
Each fixture, furthermore, comprises one or more downwardly opening sockets in the bottom wall, and the table is provided with vertically reciprocable locating pin elements engageable with the sockets. The locating sockets and locating pins are preferably tapered and are precisely located on the fixture and on the table so that, when a locating pin is engaged in a locating socket, the fixture becomes precisely located on the table, especially with reference to the axis of the tool, or tools, driven by the machine tool.
The locating pins referred to are preferably spring biased in the upward direction to slidably engage the bottom of the fixture so that the pins will enter the respective sockets as the fixture approaches the respective position. Fluid operable actuating means are provided for retracting each locating pin downwardly into the table to free the fixture for movement on the table while other fluid operable actuating means are provided for driving the locating pins upwardly to cause the locating pins firmly to engage the respective sockets and effect precise location of the fixture on the table.
BRIEF DESCRIPTION OF THE DRAWINGS
The exact nature of the present invention will become more clearly apparent upon reference to the following detailed specification taken in connection with the accompanying drawings in which:
FIG. 1 is a view showing a portion of a machine tool having a table and work member according to the present invention mounted thereon showing a work member in the process of being machined.
FIG. 2 is a plan view of the FIG. 1 arrangement showing the work member supporting fixture in different positions.
FIG. 3 is a perspective view showing the upper surface of the table.
FIG. 4 is a section indicated by line IV--IV on FIG. 3 showing a valved connection leading from a passage in the table to the surface on which the work member supporting fixture is supported.
FIG. 5 is a view like FIG. 4 but drawn at enlarged scale showing the valve held open by the fixture so that pressure fluid can flow upwardly through the valve and establish a support film between the fixture and the table.
FIG. 6 is a sectional view indicated by line VI--VI on FIG. 3, showing details in respect of a pivot pin mounted on the table.
FIG. 7 is a sectional view drawn at enlarged scale and indicated by line VII--VII on FIG. 3 and illustrating a lock pin reciprocably mounted in the table.
FIG. 8 is a fragmentary view showing a work member supporting fixture in located position on the table and clamped in place thereon.
FIG. 9 is a view like FIG. 8 but shows the clamp released and the work member fixture elevated from the table by a fluid film therebetween.
FIG. 10 is a view like FIG. 9 which shows the lock pin retracted into the table so that the work member supporting fixture is now released and is free to move on the table.
FIG. 11 is a plan view looking up from the underneath side of a typical work member supporting fixture according to the present invention.
FIG. 12 is a view like FIG. 11 but shows another type of work member supporting fixture from the underneath side.
FIG. 13 is a schematic view showing a preferred form for the fluid control circuit according to the present invention.
FIG. 14 shows a center pin which is retractable.
FIG. 15 shows a modification in which a locating pin is provided with a valve providing for selective control of the respective pin.
FIG. 16 is a schematic perspective view of a machine tool having a rotary table.
FIG. 17 is a fragmentary view showing a portion of FIG. 16 at enlarged scale.
FIG. 18 is a fragmentary view drawn at still further enlarged scale.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings somewhat more in detail, FIG. 1 is a relatively schematic view of a machine tool having a bed 10 and a working tool 12 which may be rotatable or reciprocable according to well known practices in the machine tool art.
According to the present invention, there is a table or plate 14 mounted on bed 10 in a predetermined position thereon. Table or plate 14 is fixedly connected to bed 10 and may comprise the bed itself, on occasion.
Resting on table 14 is a work member supporting fixture 16 in which a work member 18 is mounted for being machined by tool 12. The table 14 has an upwardly facing top surface 20 and fixture 16 has a downwardly facing bottom surface 22 resting on surface 20. Table 14 is also provided with T-slots 24 for slidably receiving clamp devices which are operable for clamping fixture 16 fixedly in place on table 14 when the fixture is in a desired position thereon.
FIG. 2 is a plan view looking down on top of table 14 and fixture 16 and also shown in dotted outline a pivot 26 which may consist of a pin upstanding from table 14 and a socket in the bottom of fixture 16 in which the pin is disposed. The pin permits the fixture to pivot about the axis of the pin to various positions on table 14 for presenting the work member in the fixture in different positions for being machined by tool 12.
FIG. 3 shows more in detail the manner in which table 14 is constructed. Table 14 in FIG. 3 will be seen to comprise a metal block of substantial area and substantial thickness so that it will support heavy work member-fixture combinations without any problems.
The table is provided with air passage means 28 formed therein and communicating with a supply conduit 30 outside table 14 and which is connected via a control valve 32 with the supply of fluid under pressure represented by conduit 34. The fluid under pressure is advantageously air, but could, conceivably, comprise another fluid medium.
Extending vertically upwardly from passage means 28 in block 14 are connection passages or conduits 35 which open through the top surface 20 of table 14. The upper end of each connecting passage is closed by a valve comprising a body so that passages 36, a valve comprising a body 38 which may be threaded into the upper end of the passage and the top of which body is disposed below the level of surface 20 of table 14. The valve body 38 is tubular and captive in the upper end thereof is a valve ball 40 which projects slightly above surface 20 as will be seen in FIG. 4. A spring 42 may be provided which continuously urges valve ball 40 into its upper closed position.
When a fixture 16 is moved on table 14 until the downwardly facing lower surface 22 of the fixture engages ball 40, the ball will be depressed as shown in FIG. 5 and admit fluid under pressure from connection 36 through the bore of valve body 38 and around ball 40 to the space between surfaces 20 and 22. The pressure of the fluid is so selected that a fluid film will be established through the surfaces which will floatingly support fixture 16 and a work member therein so that the fixture-work member combination can easily be moved about on table 14 to a desired position.
As will be seen in FIG. 3, the passage means 28 include sufficient passages to supply a plurality of outlet connections 36 which are distributed substantially uniformly over the entire area of table 14 which is to be employed during the machining of a work member mounted in a fixture resting thereon. As will be seen, the connections 36 terminate at the upper ends in the valves consisting of bodies 38 and 40 with the positions of the valve balls indicated by reference numeral 40 in FIG. 3.
The arrangement described above provides for floatingly supporting the fixture with the work member therein on table 14 so that the fixture can easily be moved about on the table without the use of power operated equipment such as hoists and the like. Rather, the fixture and the work member therein can be moved manually about on table 14 to desired positions thereon.
It is essential, however, that the fixture occupy precisely located positions so the work member in the fixture thereon will be presented properly to the tool or tools which are to perform work thereon. With this in mind, table 14 includes a main pivot pin 50 mounted in a bore provided therefor on table 14 and having an upper end projecting upwardly above surface 20 of table 14 and advantageously bevelled at the upper end as at 52.
The pin 50 is mounted in a bushing 56 and has a groove 54 to provide space for the head of a screw 58 which is threaded into a threaded bore in table 14 and has the periphery of the head engaging an annular groove 60 in pin 50 below the level of table 14. Several locations can be provided in the table 14 for such centering pins. Fixture 16 is provided with an accurate bore for receiving the upper end of pin 50.
When the fixture is introduced into the machine, it is set down on table 14 with the pin received in the bore provided therefor and, when the fluid pressure film is established between the fixture and the table, the fixture can turn relatively freely about the axis of pin 50 as shown in FIG. 2 wherein pivot means 26 corresponds to pivot pin 50 and the corresponding bore provided in the bottom of the fixture.
In addition to the pivot pin 50 which has been described, there are further pins provided in table 14 which serve for locating the fixture in predetermined positions. The locating pins referred to, one of which is shown in section in FIG. 7, are located in precise positions on table 14 with particular reference to the axis of the tools in the machine of which the table forms a part or in which the table is mounted. These pins are engageable with recesses provided in the bottom of the fixture and which are also accurately located in the fixture.
Thus, it comes about that, when one or more pins engage the corresponding recesses in the bottom of the fixture, the fixture will be in an accurately located position on the table. When the pivot pin on the table engages the fixture, only one locating pin is required to determine a fixture location but, as will be seen hereinafter, at least two locating pins could be employed, and the fixture location determined thereby without depending on a pivot pin. To this end, the pivot pin may be retractable into the bed as will also be described hereinafter.
FIG. 7 is a section indicated by line VII--VII on FIG. 3 and shows that the bottom of fixture 16 is provided with bores 70 in which bushings 72 having tapered holes are mounted.
Table 14 is also provided with bores and each bore at the upper end has an elongated bushing 74 in which is slidable a pin 76 having a tapered upper end adapted for seating in the table hole in bushing 72.
At the lower end thereof, pin 76 is connected with a double acting piston 78 spring biased upwardly toward the position illustrated in FIG. 7 by compression spring 80. Each piston 78 has an upwardly facing fluid operable area 82 adapted to receive pressure fluid from a conduit 84 in table 14 to drive the piston and pin 76 downwardly until the upper end of the pin is below the upper surface 20 of table 14.
Alternatively, a supply of pressure fluid to the downwardly facing fluid operable area 86 of the piston from conduit 88 formed in table 14 will drive piston 78 and pin 76 upwardly to effect firm engagement of tapered end 76 with bushing 72.
The lower end of the bore in table 14 in which the piston 78 and pin 76 are mounted is closed by a cover plate 90.
FIGS. 8, 9 and 10 schematically illustrate various steps in connection with the practice of the present invention.
In FIG. 8, a fixture 16 will be seen to be clamped to table 14 by hydraulic clamping device 100 having a vertically movable chute 102 engaging a suitable upwardly facing region of fixture 16 while the hydraulic clamp has a further portion 104 slidable in a respective T-slot 24 of table 14.
In FIG. 8, the hydraulic clamp is engaged and is holding the fixture 16 down on the table while a lock pin 76 may have the respective piston 78 under pressure from below driving the lock pin upwardly into locating position. The air supply to the space beneath the bottom of fixture 16 and the top of table 14 and represented in FIGS. 8, 9 and 10 by conduit 106 is interrupted in FIG. 8.
The releasing of fixture 16 will be seen in FIG. 9 wherein it will be noted that clamp 100 has been actuated to retract chute 102 upwardly while a supply of air under pressure is initiated by a conduit 106 thereby to lift or float fixture 16 upwardly a short distance from the upper surface 20 of table 14.
By supplying air under pressure to the upper side of piston 78, pin 76 will be moved downwardly to the FIG. 10 position thereof. With the parts in the FIG. 10 position, the fixture 16 is movable on the supporting air curtain either in rotation, if a pivot pin is engaged with a hole in the bottom of the fixture, or in translation, if a pivot pin or table 14 is engaging slot means formed in the bottom of fixture 16, or in any direction, if there are no pivot pins on table 14 engaging the fixture.
A pair of typical fixtures are shown in FIGS. 11 and 12 looking up from below. The fixture 120 in FIG. 11 has slots 122 which may be provided for assisting in connecting a work member thereto. The table has a slot 124 formed into the bottom for receiving a pivot pin on the table and which will permit translation and rotation of the fixture on the table.
The fixture is also provided with a plurality of lock pin holes 126 distributed thereover and each adapted for receiving a table lock pin on the table. With the arrangement of FIG. 11, rotation and translation of the fixture 120 can be had to a plurality of different locations in which a work member thereon can be machined.
In FIG. 12, the fixture 130 is a central hole 132 for receiving a pivot pin while circumferentially distributed around the hole and spaced equal radial distances therefrom are lock pin holes 134 for receiving lock pins. With the arrangement of FIG. 12, the fixture is rotatable about the axis of hole 132 to various positions such as the right angles to the position illustrated or at 45 degrees from the position, unless the pivot pin engaging hole 132 is retractable whereupon the fixture of FIG. 12 would also be translatable.
A simplified showing of the circuit for actuating the locating pins is shown in FIG. 13. In this Figure, a source of pressure 140 is supplied through an air accumulator to the pressure inlets of valves 142 and 144. Each of these valves is a three position valve and operable for reversibly connecting the fluid inlet to one or the other of the service conduits connected thereto while exhausting the other service conduit and also having a position in which both of the service conduits are connected to exhaust.
The valve 142 may have the one service line connected to the upwardly facing sides of a pair of locating pin actuating pistons 146 and 143 with the other service line connected to the underneath sides of the pistons.
Valve 144, similarly, has one service line connected to the upwardly facing sides of pistons 150 and 152 pertaining to locating pins while the other service conduit is connected to the underneath sides of the pistons.
The conduits leading to the underneath sides of the pistons connected through needle valves 154 to a pilot cylinder 156 on a reversing valve 158 having a pressure inlet connected through the valve to the aforementioned conduit 34 representing the pressure supply to the table 14 for floating the fixture 16 thereon.
Valve 158 is normally held in position to supply pressure to conduit 34 by spring 160 but will move into position to exhaust conduit 34 when the pressure in pilot cylinder 156 reaches a predetermined amount. Thus, when the valves 142 and 144 are actuated to drive the locating pins upwardly into locating position, after the pins become seated, the pressure built up on the underneath sides of the pistons will cause valve 158 to shift to interrupt the air supply to the fluid cushion of fixture 16.
Similarly, a valve arrangement at 162 could be actuated in a similar manner via needle valve 164 so that following shifting of valve 158 to interrupt the air cushion, the hydraulic clamping device would be actuated.
The sequence of steps could, of course, be entirely under the control of manual valves, if so desired.
FIG. 14 shows how a centering pin 220 could be connected to a piston 222 reciprocable in cylinder 224 in the table 14 with fluid under pressure being supplied to opposite ends of cylinder 224 by passages 226 and 228 in the table. With the FIG. 14 arrangement, the pin 220 can be retracted into the table out of the range of movement of fixture 16, or it can be moved upwardly to engage a centering hole or slot in the fixture.
FIG. 15 shows a locating pin 230 connected to a piston 232 reciprocable in a cylinder 234 in the table; the same as is shown in FIG. 13. The difference in the arrangement of FIG. 15 is the provision of a selector valve 236 actuating solenoids 238 and 240 and providing for selective actuation of locating pin 230 so that it could be used as a centering pin for certain purposes, if so desired.
The present invention is also adapted for use in cases where the table is rotatable. With a fixture mounted on such a rotatable table, the table can be caused to rotate freely for a positioning of the fixture while pin and socket means are provided with the socket means on one end of the table and fixture and the pin means on the frame of the tool for fixing the table and the fixture thereon in predetermined rotated positions.
The construction of many of the lathe-type machine tools is such that the tool holding side head, or the tool holding turret side head, positions the tool in such a way as to bisect the circular table holding the work member. However, in any event, the pin can be located as a part of the machine tool, or independent of the machine tool, in such a way as to be exactly in line with the tool centers as they pass across the table, reaching various portions of the diameter of the table.
In most instances, it would be preferable for the pin, its housing, and the actuating unit, to be located on the bottom portion of the side head turret. The center of the pin would be in exact agreement with the center of the other tools housed in the turret, and consequently bisecting the table, and exactly in line with other tool stations on the machine tool, such as turret head traveling over the work member supported by a carriage, either in the horizontal or vertical environment.
The socket locating holes machined on the outer periphery of the circular bed and/or circular fixture plate resting on the circular table provide for location of the drill or milling cutter to the workpiece in an "X" environment, while a manual or N/C movement of the carriage, housing the drilling or milling cutting tool provides the "Y" environment.
In many cases, circular parts have bolt hole drilling requirements such that the "Y" environment once established will not move until the bolt circle has been completed. Also, in many cases, a keyway or similar surface must be located accurately with respect to the drilled holes on the work member, or with respect to some other important configuration of the work member. The cooperating socket holes perform this locating function quickly, easily and accurately.
The socket locating holes could be machined in the outer periphery of the machine tool circular table in one or more rows, or in other configurations as required. In addition, special socket hole locations for highly special parts might be incorporated in the periphery of circular work member holding fixture plates which are attached to the circular machine tool bed.
The socket locating holes might incorporate a tapered bushing if properly affixed to avoid a safety problem; might be taper machined directly into the bed and strengthened through hardening; or might be straight bore holes so that the cooperating pin, having a slightly tapered front end, might be inserted in a relatively slow manual environment with high reliability.
The pin, itself, located in a housing, held rigidly in place, preferably on the lower portion of the side head turret station so that it can make contact with any and all cooperating holes on the machine tool bed and bisect the table, similar to other cutting tools housed in the turret. The pin itself should be very rigid, an inch or more in diameter, properly supported inside the housing in order to be injected straight forward in the desired line.
The pin should preferably be tapered to match a cooperating tapered locating hole; however, it might, under a number of circumstances, be slightly tapered in the front to provide for the initial locating, and then a straight section of the pin driven into a straight section of the cooperating hole. This arrangement would provide for a somewhat larger contacting surface and would hold the table rigidly, even though the table would be in a free rotating environment on the machine tool, with sufficient force to hold the table rigid to permit the desired milling or drilling to the work member.
The pin could be injected or withdrawn through the use of a screw, cam-level or similar devices; however, it is more preferable that the pin utilize the initial spring locating feature, and the follow-up fluid pressure system outlined previously. In a sophisticated machine tool control environment, this pin might be operated by a machine tool control system in conjunction with a breaking device on the rotating table, and/or provide the signal for beginning the next function, such as the machining operation.
The arrangement described immediately above is shown FIGS. 16 through 18 wherein 200 is the frame of a machine having a table 202 rotatable therein and adapted for receiving a workpiece supporting fixture according to the present invention.
In the particular modification illustrated, table 202 has socket means 204 therein with pin means 206 carried in a housing 208 secured to one side of side head turret 210. As mentioned, the socket means could be provided in a fixture mounted on the table but now shown in FIGS. 16 and 17.
FIG. 18 shows the construction of pin 206 and the housing 208 therefor, and it will be seen that the pin is biased by a spring 211 toward socket engaging position and may, further, be under the control of, for example, fluid pressure supplied via conduits 212.
As mentioned above, pin means 206 could be under automatic control, if so desired.
Modifications may be made within the scope of the appended claims.
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Apparatus for locating a work member supporting fixture on a table and for clamping the fixture in located position on the table, especially to locate and clamp the work member during machining; in which the table is fixedly mounted in place, for example, in a machine tool with an upwardly facing horizontal surface exposed. The work member fixture has a downwardly facing surface receivable on the upper surface of the table and is adapted for fixedly supporting a work member therein. The table has passages therein under fluid pressure and a plurality of outlets lead from the passages through the upper surface of the table and are preferably provided with normally closed valves adapted to be actuated into open position by movement of a fixture thereover. The passages and outlets provide means for establishing a fluid film under pressure between the downwardly facing surface of the fixture and the upwardly facing surface of the table so that the fixture floats on the film and can be moved about easily on the table. Cooperating elements of pin and socket locating devices on the fixture and table provide for the location of the fixture in predetermined positions on the table and clamps are provided to clamp the fixture in located positions on the table. The locating devices on the table bear a predetermined relation to the work axis of the machine tool, a spindle axis, for example, and can, therefore, be depended on to locate the fixture in predetermined accurate positions for machining. A work member located in the fixture can, thus, be positioned rapidly for the machining of various regions thereof.
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This invention relates to a starch-based alkaline corrugating adhesive composition which provides improved corrugator running speeds. More particularly, it relates to relatively high solids corrugating adhesive compositions employing tapioca starch as the ungelatinized raw starch together with a gelatinized carrier component comprising a high amylose starch.
The procedures employed in the production of corrugated paperboard usually involve a continuous process whereby a strip of paperboard is first corrugated by means of heated, fluted rolls. The protruding tips on one side of this fluted paperboard strip are then coated with an adhesive, and a flat sheet of paperboard, commonly known in the trade as a facing, is thereafter applied to these tips. By applying heat and pressure to the two paperboard strips thus brought together, an adhesive bond is formed therebetween. The above-described procedure produces what is known to those skilled in the art as a single-faced board in that the facing is applied to only one surface thereof. If a double-faced paperboard is desired, in which an inner fluted layer is sandwiched between two facings, a second operation is performed wherein the adhesive is applied to the exposed tips of the single-faced board and the adhesive-coated tips are then pressed against a second facing in the combining section of the corrugator under the influence of pressure and heat. The typical corrugating process and the use of operation of corrugators in general are described in U.S. Pat. Nos. 2,102,937 and 2,051,025 to Bauer.
The particular adhesive employed in the corrugating process is selected on the basis of several factors, including the type of bond required in the final application of the finished corrugated product. Starch-based adhesives are most commonly used due to their desirable adhesive properties, low cost and ease of preparation.
The most fundamental of starch corrugating adhesives is an alkaline adhesive which is comprised of raw, ungelatinized starch suspended in an aqueous dispersion of cooked starch. The adhesive is produced by gelatinizing starch in water with sodium hydroxide (caustic soda) to yield a primary mix of gelatinized or cooked carrier, which is then slowly added to a secondary mix of raw (ungelatinized) starch, borax and water to produce the full-formulation adhesive. In the corrugating process, the adhesive is applied (usually at between 25° and 55° C.) to the tips of the fluted paper medium or single-faced board, whereupon the application of heat causes the raw starch to gelatinize, resulting in an instantaneous increase in viscosity and formation of the adhesive bond.
It is often desired or necessary in the manufacture of corrugated paperboard that the adhesive composition used in the process is selected to emphasize one or more important properties such as water resistant bonds, viscosity stability, pot life and the like. The adhesive compositions of the present invention are formulated to possess improved tack (also known in the corrugating art as "green bond strength") which translates to increased corrugator running speeds.
There are different theories regarding the respective roles of the raw starch and the carrier in the development of adhesive properties, but there is substantial evidence to support the view that the carrier contributes to the bond strength and set speed of the adhesive, and that good tack in the carrier leads to good tack and therefore improved runnability in the full-formulation adhesive (see R. Williams, C. Leake and M. Silano, TAPPI, Vol. 60 Nr 4 April/1977 pp 86-89).
It has been known for many years that a corrugated adhesive whose carrier portion is prepared from a high amylose starch is superior to one prepared from pearl starch, which contains about 27% amylose, because a carrier can be produced having improved rheological and film-forming properties, and increased moisture resistance. There are strong indications that the tack of the carrier also plays an important role in the corrugating process. Recent developments indicate that further improvements in tack can be achieved by specific combinations of particular starches employed as the raw starch and carrier in high solids formulations. These improvements in tack and green bond strength permit higher corrugating machine speeds as compared to corrugating adhesives known in the prior art.
SUMMARY OF THE INVENTION
It has now been discovered that improved and superior green bond strength and tack is developed in alkaline curing corrugating adhesives by the combination of tapioca starch as the ungelatinized raw starch and a carrier comprising gelatinized (cooked) high amylose starch in high solids formulations. In accordance with the invention, a corrugating adhesive composition having improved tack and corrugator speeds is obtained with the following components:
1. an ungelatinized tapioca starch;
2. a carrier starch comprising a high amylose starch or high amylose starch blend;
3. alkali such as sodium hydroxide;
4. borax; and
5. water: wherein the ungelatinized starch, carrier starch, alkali, borax and water are present in amounts of 23-42%, 1-9%, 0.2-1.3%, 0.2-1.3%, 55-70%, by weight, respectively, based on the total adhesive composition. The ranges for the starch components are given on a "dry basis", (d.b.).
While in many corrugating adhesives in the prior art the ungelatinized starch can be used at a variety of starch solids, experience has indicated that in industry, most corrugators are using corrugating adhesives containing from about 18-26% (d.b.) by weight of total solids. In the present invention, the improved tack and speed requires the use of adhesives which contain from 30-45%, preferably from 30-40% by weight of total solids. In the preferred adhesives having 30-40% solids, the maximum amount of ungelatinized tapioca employed in these adhesives will amount to about 38% (d.b.) by weight of the total adhesive.
DETAILED DESCRIPTION OF THE INVENTION
The raw starch component of the adhesive, in accordance with the invention, is a tapioca starch. Small amounts of starches other than tapioca such as starches derived from corn, potato, wheat, waxy maize, as well as high amylose starches, can be employed in replacing a portion of the tapioca starch without any significant loss of properties in the adhesive. For example, up to 20% of the tapioca starch may be replaced with a starch such as waxy maize or corn starch.
The carrier component of the present adhesive comprises a high amylose starch, i.e., a hybrid corn starch having an amylose content of from about 50 to 75%. Blends of high amylose starches and other starches which are not considered as having a high amylose content (namely those having an amylose content below 50%) are permissible. For purposes herein, the starch blend of the carrier component should contain at least 40% and preferably 50% by weight of amylose, and the high amylose starch (or blend thereof) employed as the carrier is used in an amount of from about 1 to 9% (d.b.) based on the weight of the adhesive.
The alkali (base) employed herein is preferably caustic soda, i.e., sodium hydroxide; however, other bases may be employed in partial or full replacement of the sodium hydroxide and include, for example, alkali metal hydroxides such as potassium hydroxide, alkaline earth hydroxides such as calcium hydroxide, alkaline earth oxides such as barium oxide, alkali metal carbonates such as sodium carbonate, and alkali metal silicates such as sodium silicate. The alkali may be employed in aqueous or solid form.
In addition to the essential ingredients of the adhesive composition of this invention, any conventional non-chemically functional additives may be incorporated into the adhesive in minor amounts, if desired. Such additives include, for example, wetting agents, proteins, plasticizers, solubilizing agents, rheology modifiers, water conditioners, penetration control agents, peptizers such as urea, gelatinization temperature modifiers, inert fillers such as clay and finely ground polymers, thickeners such as inorganic collodial clays, guar, hydroxyethyl cellulose, alginates, polyvinyl alcohol, polymers of ethylene oxide and the like, wet strength resins and emulsions such as polyvinyl acetate.
In the preparation of the corrugating adhesives herein, the preparation method used by the practitioner can vary without serious consequences. Ordinarily, however, the carrier starch is first gelatinized (cooked) in a portion of the water with the alkali (caustic soda) to provide the carrier component of the adhesive. In a separate vessel, a mixture or slurry is made of the raw starch, borax and remaining water. The carrier and raw starch mixture are combined to form the final adhesive. Optional ingredients, if desired, can be added at any convenient point during the preparation of either component but are usually added to the finished adhesive.
The adhesive thus obtained can be used to bond single or double-faced boards using any equipment which is presently employed for the preparation of corrugated board. Thus, the adhesive is maintained at a temperature preferably between 25° and 55° C. before its application to the protruding tips of the fluted paper strip. The actual application may be accomplished by the use of glue rolls which are ordinarily employed in most corrugating machines, or one may, if desired, utilize other application methods which may be able to achieve a different distribution of adhesive. Following the application of the adhesive to the fluted paper strip, the latter is then brought into immediate contact with the facing board under the influence of heat and pressure, as is well known in the art. A double-faced board may be subsequently prepared by bringing a second facing in contact with the open fluted surface of the single-faced board by the usual procedures.
The examples which follow illustrate specific embodiments of the invention. In the examples all parts and percentages are given by weight and all temperatures in degrees Fahrenheit and degrees Celsius.
The following testing procedure was used in the examples to characterize the tack of the various adhesives herein in preparing corrugated board.
TEST PROCEDURE
In evaluating the various adhesives for tack and green strength, the test adhesive was employed on a single-facer pilot plant corrugator in producing corrugated board using standard 69 lb./MSF wet strength liner board and 33 lb./MSF wet strength medium The corrugated single-faced web is taken immediately after production as the corrugator was running with each of the test adhesives. A sufficient portion of the liner was separated from the medium so as to enable the attachment of dial-type spring scale with a 2,000 g. capacity The liner was separated from the medium in a continuous fashion as the green bond strength (tack) is building with time. The time taken to achieve 2,000 g. of tack (green bond) was recorded. On a relative basis, the shorter the time required to achieve the 2,000 g. of tack (the point where fiber tear begins to develop), the faster the adhesive will run on the corrugator.
EXAMPLE I
This example illustrates the preparation of a corrugating adhesive representative of the invention and illustrates its improved tack and running speeds as compared to two prior art adhesives.
A carrier component was prepared by cooking at 105° F. (41° C.) 1,200 g. (1,056 g. d.b.) of a high amylose starch (amylose content 67-72%) in 6,560 g. of water and 240 g. of a 50% solution of sodium hydroxide until the starch was gelatinized. In a separate vessel, 7,200 g. (6,336 g. d.b.) of tapioca starch was added to 8,225 g. of water at 90° F. (32° C.), followed by the addition of 96 g. of borax (decahydrate) to provide a raw starch slurry. After 10 minutes of moderate agitation, the carrier starch cook was slowly added to the raw starch slurry and moderate agitation was continued. This adhesive was designated "Adhesive A".
Two prior art corrugating adhesives, designated "Adhesive B" and "Adhesive C", were prepared as follows.
Adhesive B--A carrier component was prepared by cooking at 160° F. (71° C.) for about 20 minutes 570 g. (502 g. d.b.) of corn starch (amylose content about 27%) in 3,753 g. of water and 96 g. (dry) of sodium hydroxide. The starch was gelatinized at the end of the 20-minute period. In a separate vessel, 3,600 g. (3,168 g. d.b.) of corn starch was slurried in 7,756 g. of water at 90° F. (32° C.), followed by the addition of 96 g. of borax (decahydrate). After 10 minutes of moderate agitation, the carrier cook was slowly added to the raw starch slurry with moderate agitation.
Adhesive C--A carrier component was prepared by cooking at 160° F. (71° C.) for 20 minutes 540 g. (475 g. d.b.) of corn starch (amylose content about 27%) in 4,505 g. of water with 300 g. of a 50% solution of sodium hydroxide. In a separate vessel, 8,640 (7,603 g. d.b.) of corn starch was slurried in 9,910 g. of water at 90° F. (32° C.), followed by the addition of 115.2 g. of borax (decahydrate). After 10 minutes of stirring, the carrier cook was slowly added with agitation to the raw starch slurry.
Table I characterizes the three adhesives and summarizes the results achieved in evaluating the adhesives in the tack test described above.
TABLE I______________________________________ Adhesive A Adhesive B Adhesive C______________________________________Raw Starch tapioca corn cornCarrier high amylose corn cornTotal Solids of 32.3% 24.3% 34.7%AdhesiveTime to reach 2,000 g. 7 sec. 23 sec. 15 sec.of tack______________________________________
The data shows superior tack was achieved with Adhesive A of the invention as compared to Adhesives B and C.
EXAMPLE II
The adhesives of the invention have been found to exhibit superior tack in preparing corrugated board employing a liner board which has been treated to provide a moisture resistant surface. Experience has shown that such surfaces are difficult to adhere with conventional adhesives of the prior art.
An adhesive representative of the invention, Adhesive A of Example I, was compared to two adhesives of the prior art; Adhesive C of Example I and Adhesive D prepared as follows:
Adhesive D--This adhesive is prepared identical to Adhesive A of Example I except that the tapioca raw starch was replaced with corn starch.
Table II characterizes the adhesives and summarizes the results achieved in the tack test described above in which the liner used was 42 lb./MSF paper coated with thermoset resin for providing moisture resistance.
TABLE II______________________________________ Adhesive A Adhesive C Adhesive D______________________________________Raw Starch tapioca corn cornCarrier high amylose corn high amyloseTotal solids of 32.3% 34.7% 32.3%adhesiveTime to reach 2,000 g. 18 sec. 50 sec. 30 sec.of tack______________________________________
Again, the data shows the adhesive of the invention to have superior tack as compared to the described prior art adhesives.
EXAMPLE III
The following example describes an evaluation run on a commercial type corrugator.
An adhesive representative of the invention, designated Adhesive E, was prepared as follows. A carrier component was prepared by cooking at 100° F. (38° C.) 14 lbs. (12.4 lbs. d.b.) of high amylose starch (amylose content 67-72%) in 74 lbs. of water and 4.6 lbs. of a 50% solution of sodium hydroxide until the starch was gelatinized. In a second container, 140 lbs. (123.2 lbs. d.b.) of tapioca starch was slurried in 163 lbs. of water at 105° F. (41° C.) to which was added 1.3 lbs. of borax (decahydrate). To provide the final adhesive, the high amylose carrier cook was slowly added to the raw starch slurry.
A prior art adhesive, designated Adhesive F, was prepared as follows. A carrier was prepared by adding 150 lbs. (132 lbs. d.b.) of starch containing approximately 30% amylose to 1,460 lbs. of water at 130° F. (54° C.). Thereafter 28 lbs. of dry caustic and 10 lbs. of borax (decahydrate) was added and the mixture was cooked for about 20 minutes, after which 1,250 lbs. of cooling water was added. In another container 1,100 lbs. (968 lbs. d.b.) of cornstarch was added to 1,420 lbs. of water containing 15 lbs. of borax (decahydrate). The final adhesive was provided by adding the carrier starch cook to the corn starch slurry with moderate agitation.
Each of the adhesives was run on a full size corrugator with the maximum speed obtainable without delamination being noted. Results are summarized in Table III.
TABLE III______________________________________ Adhesive E Adhesive F______________________________________Raw Starch tapioca cornCarrier high amylose 30% amyloseTotal solids of 35.1% 27.5%adhesiveRunning speed 750 fpm.* 475 fpm.maximum______________________________________ *feet per minute
EXAMPLE IV
In this example, Adhesive E of Example III was compared against a prior art adhesive described below by running on a full size corrugator using 76 lbs./MSF liner and 33 lbs./MSF waxed medium.
The prior art adhesive used herein was prepared by cooking 200 lbs. (176 lbs. d.b.) of a carrier starch whose amylose content was approximately 38%, in 835 lbs. of water at 130° F. (54° C.). Sodium hydroxide, 38 lbs. dry, was added and the starch allowed to cook for 18 minutes after which time cooling water totaling 60 lbs. was then added. In a second container, 1,300 lbs. (1,144 lbs. d.b.) of corn starch was added to 3,087 lbs. of water containing 19 lbs. of borax (pentahydrate) to provide a raw starch slurry. The final adhesive was prepared by adding the carrier to the raw starch slurry with moderate mixing. The solids of this adhesive totaled 24.9% by weight.
In running the above paper stock, maximum speeds of 755 fpm. were obtained with Adhesive E of the invention while a maximum speed of 500 fpm. was obtained with the described prior art adhesive.
Now that the preferred embodiments of the present invention have been described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly the spirit and scope of the present invention is to be limited only by the appended claims, and not by the foregoing disclosure.
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Alkaline-curing, starch-based corrugating adhesives employing ungelatinized tapioca starch and a carrier comprising high amylose starch, wherein the total solids of the adhesive is from 30 to 45% solids by weight, are disclosed. Said adhesives provide improved tack and corrugator running speeds.
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FIELD OF THE INVENTION
[0001] The invention relates to pharmaceutical compositions comprising a compound of formula (I) for use in the treatment of dermal wounds. The topical pharmaceutical composition may be used for the treatment of wounds affecting the deeper layers of the skin, including connective tissue. The pharmaceutical composition may comprise other active agents contributing to wound healing in addition to the compound of formula I.
STATE OF THE ART
[0002] The skin is the largest organ in humans providing protection against physical and chemical harm and causative agents. Hence, the appropriate healing of dermal wounds is necessary for the homeostasis. Wound regeneration is a complex process which requires a well-orchestrated interaction of different cell types.
[0003] Several topical formulations are known for the treatment of dermal wounds. Most of them promote the healing of superficial wounds and abrasions by facilitating epithelialization and exerting antibiotic- and anti-inflammatory effects (e.g. dexpanthenol containing formulations which facilitate epithelialization in burns and irritation and may be used as a supplemental therapy for chronic wounds, too).
[0004] Antimicrobial tinctures (e.g. povidone iodide, ethyl-hexyl-glycerol) and disinfectant solutions (e.g. hydrogen peroxide) eliminate causative agents but may also damage the epidermis and the dermis. Further, residual disinfectants in the wound may lead to irritation, inflammation.
[0005] Hyaluronate containing formulations promote tissue renewal and can be used for the acceleration of normal wound healing such as for the therapy of chronic wounds. Antibacterial agents (e.g. zinc, silver-sulfadiazine) are often added to hyaluronate containing formulations.
[0006] Joint application of fibrinolizine and dezoxiribonuclease leads to the decay of damaged cells resulting in clean wound surfaces which contributes to a better healing. The field of application comprises infected wounds or wounds carrying the risk of infection, chronic wounds and ulcers. Formulations containing collagenases or proteases have the same mechanism of action. If the wound is treated with disinfectant prior to their application, enzymes may be inactivated by the disinfectant as a result of inappropriate rinsing. Moreover, enzymes may irritate the healthy tissue surrounding the wound.
[0007] Sodium samarium disulfosalicilate, a non-steroid anti-inflammatory drug (NSAID) is applied in certain forms of acute dermatitis.
[0008] In clinical practice, negative pressure wound therapy, NO, hyperbaric oxygen, CO2 and growth factors can also be applied in the treatment of chronic wounds. (Daróczy et al., 2011ezt ellenörizni kell, magyarul nem ez van).
[0009] Dantrolene is a derivative of hydantoin, known since the 1960ies. This compound inhibits muscle contractility particularly in striated muscles through its effect on ryanodine receptors. However, the mentioned effect is characteristic of the heart and smooth muscle, as well. The original indication of dantrolene is muscle relaxation. In the USA and many European countries it is on market as a muscle relaxant especially for spastic conditions in which other drugs fail to work.
[0010] It has been described in the seventies that dantrolene is effective in the treatment of malignant hyperthermia which is a life-threatening complication of anesthesia originating in a mutation of ryanodine receptor type I. Until now, dantrolen is the only effective therapy for this disorder (Harrison, 1975). Malignant hyperthermia is the major indication for the use of dantrolene, but it may be applied in the treatment of neuroleptic malignant syndrome and ecstasy intoxication, too.
[0011] The Hungarian National Institute of Pharmacy recommends dantrolene for the treatment of malignant hyperthermia only (see the description on the website of the Institute).
[0012] US 20090306163 patent application reveals a dantrolene-containing cosmetic product which may be suitable for the prevention or treatment of wrinkling by muscle relaxant effect of dantrolene.
[0013] JP2007308403 patent application describes a dantrolene-containing medical product which can be applied locally in inflammatory disorders and burns. This invention utilizes the muscle relaxant effect of dantrolene, because muscle relaxant drugs soothe muscle contraction following the damage, improve microcirculation and reduce inflammation.
[0014] JP2011250728 patent application describes a method for the screening of compounds which may regenerate impaired barrier function after superficial injuries or due to skin aging. Agents identified by the method may be used in cosmetic products which prevent dehydration of the skin. The advantage of the method is that it may replace animal experiments in testing ingredients of cosmetic products. The method has identified compounds which inhibit the ryanodine receptors. Thus, the examples mention dantrolene which is an antagonist of ryanodine receptors.
[0015] According to the data obtained in animal experiments by Denda and coworkers (Denda et al., 2012), local application of dantrolene accelerates barrier regeneration after removal of the uppermost layer of the epidermis.
[0016] In the course of our research activity, it has unexpectedly been recognized that dantrolene positively affects the healing of large, full-thickness dermal wounds.
DEFINITIONS
[0017] Dermal wound, as used herein is a discontinuity of the skin, and optionally, that of the skin and the underlying tissues. Wounds may be simple or complex. Simple, superficial- or moderately deep wounds affect the skin, while complex or deep wounds may affect the underlying muscles, nerves, bones and vessels as well. The term dermal wound is used herein for both acute and chronic, difficult-to-heal wounds. Full-thickness wounds are wounds affecting each layer of the skin inclusive connective tissue, and optionally connective tissue under the skin.
[0018] Skin tissue (briefly skin) is an extended organ with barrier function comprising the following 3 layers: epidermis, dermis and subcutis.
[0019] Epidermis is a keratinized stratified squamous epithelium, the cells of which are continuously being replaced from the stratum basale. Melanocytes can also be found in the epidermis. In the present description, the upper layer of the skin refers to the epidermis or its uppermost cellular layers.
[0020] Dermis consists of loose connective tissue and contains vessels, nerve endings and skin appendages (hair follicles, sebaceous glands and sweat glands).
[0021] Hypodermis contains connective tissue and fat.
[0022] Subject is a human or another vertebrate in need of a treatment promoting the healing of the dermal wound.
[0023] (Wound) Dressing is defined as an interactive product which can be utilized in wound treatment. Interactive dressings build a physical or chemical interaction with the wound. This category comprises hydrogels, hydrocolloids, alginate-based bandages, film and matrix bandages and impregnated meshes.
[0024] Throughout the description, the terms comprise(s), comprising indicate that an object comprising something may comprise other components, as well. Thus, a list of one or more elements following the verb “comprise(s)”, “comprising” does not exclude the presence of other components. E.g. a medical product which comprises an active substance may also comprise other agents or any type of additives. A special variation of the verb consist is essentially consisting of something which means that an object comprising the listed components, comprises beyond the list only such components which do not contribute to its main effect. For example, a medical product, which essentially consists of a certain active agent, may contain additives that do not change (especially not substantially) the biological effect, but the product does not comprise any other active agent.
[0025] In the description, the use of singular forms or definite articles does not exclude the interpretation as plural on determination of the scope of protection, unless it is indicated or the context suggests contrariwise.
[0026] The terms “one”, “a”, or “an”, unless otherwise indicated or where the context requires otherwise are used as an indefinite article and not as a numeral.
BRIEF DESCRIPTION OF THE INVENTION
[0027] The invention relates to a pharmaceutical composition for use in the treatment of a dermal wound in a subject in need of such a treatment, wherein the pharmaceutical composition comprises as an active agent a ryanodine receptor antagonist compound of general formula (I),
[0000]
[0000] wherein in formula (I)
Q is an electron withdrawing group preferably selected from halogen atoms, preferably Br, Cl or F; pseudohalogen, such as azido, thiocyano, or cyano; nitro, unsubstituted amino, substituted amino, preferably methylamino, ethylmethylamino or dimethylamino; hydroxy, C 1-4 alkyloxy, preferably methyloxy or ethyloxy; X 1 and X 2 are (a) sp2 carbon atoms to which a H or methyl is attached or (b) sp2 nitrogen atom, wherein preferably when X 1 is defined by (b), X 2 is defined by (a) and when X 2 is defined by (b), X 1 is defined by (a) or both X 1 and X 2 are defined by (a) R 1 is a hydrogen atom, C 1-4 alkyl, C 2-4 alkenyl, the alkyl or alkenyl being unsubstituted or substituted, wherein the substituent is preferably selected from the group consisting of halogen atoms, preferably I, Br, Cl or F; azido, amino, which may be unsubstituted or substituted, preferably methylamino, ethylmethylamino or dimethylamino; or R 1 is aryl or heteroaryl, preferably phenyl, benzyl or tolyl, which is unsubstituted or substituted with a substituent preferably selected from the group consisting of halogen atoms, preferably I, Br, Cl or F; azido, amino, which may be unsubstituted or substituted, preferably methylamino, ethylmethylamino, or dimethylamino, and R 2 is a hydrogen atom, hydroxy, C 1-4 alkyloxy, preferably methyloxy or ethyloxy; unsubstituted or substituted C 1-4 alkyl, wherein the substituent is preferably selected from the group consisting of halogen atoms, preferably I, Br, Cl or F; azido, amino, which may be unsubstituted or substituted, preferably methylamino, ethylmethylamino or dimethylamino;
or a pharmaceutically acceptable salt thereof, such as a sodium salt thereof and a pharmaceutically acceptable vehicle, carrier and/or excipient.
[0033] In a preferred embodiment the active agent of the composition is a compound of general formula (I), wherein in formula (I)
Q is an electron withdrawing group preferably selected from halogen atoms, preferably Br, Cl or F;
[0035] pseudohalogen, such as azido, thiocyano, or cyano; nitro, unsubstituted amino, substituted amino, preferably methylamino, ethylmethylamino or dimethylamino; hydroxy, C 1-4 alkyloxy, preferably methyloxy or ethyloxy;
X 1 and X 2 are (a) sp2 carbon atom to which a H or methyl is attached or (b) sp2 nitrogen atom, wherein preferably when X 1 is defined by (b), X 2 is defined by (a) and when X 2 is defined by (b), X 1 is defined by (a) or both X 1 and X 2 are defined by (a), R 1 is a hydrogen atom, C 1-4 alkyl, C 2-4 alkenyl, the alkyl or alkenyl being unsubstituted or substituted, wherein the substituent is preferably selected from the group consisting of halogen atoms, preferably I, Br, Cl or F; azido, amino, which may be unsubstituted or substituted, preferably methylamino, ethylmethylamino or dimethylamino; or R 1 is C 6-14 aryl or C 4-14 heteroaryl, wherein the heteroaryl comprises 1 to 5, preferably 1 to 3 heteroatoms selected from N, O, S; wherein the aryl or heteroaryl may be unsubstituted or substituted with a substituent preferably selected from the group consisting of methyl, ethyl, propyl, isopropyl, halogen, preferably I, Br, Cl or F; azido, hydroxy, amino, which is unsubstituted or substituted, preferably methylamino, ethylmethylamino or dimethylamino, and/or optionally R 1 is not H, R 2 is a hydrogen atom, hydroxy, C 1-4 alkyloxy, preferably methyloxy or ethyloxy; unsubstituted or substituted C 1-4 alkyl, wherein the substituent is preferably selected from the group consisting of halogen atoms, preferably I, Br, Cl or F; azido, hydroxy, amino, which is unsubstituted or substituted, preferably methylamino, ethylmethylamino or dimethylamino;
or a pharmaceutically acceptable salt thereof.
[0040] Preferably, when Q is a substituted amino, Q is attached via the N of the amino group and/or when Q is alkoxy, Q is attached via the 0 of the alkoxy group.
[0041] In a preferred embodiment in the formula of the compound according to general formula (I)
[0000] Q is selected from Br, Cl or F, azido, nitro and amino,
both X 1 and X 2 are ═CH— (sp2 carbon atom to which a H atom is attached),
R 1 is H, methyl or ethyl,
R 2 is H or hydroxy,
or a pharmaceutically acceptable salt thereof.
[0042] Preferably, in the formula of the compound according to general formula (I)
[0000] Q is selected from Br or Cl, nitro and amino,
both X 1 and X 2 are ═CH— (sp2 carbon atom to which a H atom is attached),
R 1 is H or methyl,
R 2 is H or hydroxy,
or a pharmaceutically acceptable salt thereof.
[0043] The active agent in the pharmaceutical composition according to the invention is highly preferably selected from the group consisting of azumolene, hydroxy dantrolene, amino dantrolene and dantrolene and a pharmaceutically acceptable salt thereof. The compound is preferably or highly preferably dantrolene or a pharmaceutically acceptable salt thereof.
[0044] The compound of the invention is a ryanodine receptor (RyR) antagonist. Preferably, the compound of the invention increases blood flow, particularly the blood flow of the wound edges and in capillaries, particularly as monitored by Laser Doppler. The compound of the invention preferably increases the diameter of blood vessels, particularly as monitored by IVM (intravital video microscopy).
[0045] Preferably the dermal wound is a wound that extends into a layer under the epidermis.
[0046] Highly preferably the dermal wound extends into all layers of the skin, including connective tissue, optionally connective tissue under the skin.
[0047] Highly preferably the dermal wound is associated with a chronic disease, wherein the chronic disease is preferably diabetes mellitus.
[0048] The dermal wound is preferably not a burn. Preferably, the dermal wound is not a wound that may or should be treated by a method identical to a treatment method for a burn wound, particularly not a frostbite, a wound caused by electric shock, or a wound caused by a corrosive chemical. Highly preferably the wound is not a wound to be treated basically or principally by a treatment method against inflammation or a wound that is to be treated basically or principally with a muscle relaxant agent.
[0049] According to a preferred embodiment the pharmaceutical composition is formulated for topical use. The pharmaceutical composition may be in the form of an ointment, creme, gel, spray, talcum, foam composition, patch, wound dressing, solution or suspension.
[0050] The pharmaceutical composition may further comprise an other agent useful in the healing of wounds. The additional agent useful in wound healing is e.g. selected from analgesic compounds, circulation enhancer compounds, anti-inflammatory compounds, compounds with a muscle relaxant effect, antibacterial compounds, antimicrobial compounds, enhancers of tissue forming, compounds that facilitate the degradation of damaged or dead cells, growth factors, disinfectants.
[0051] The subject is preferably a vertebrate animal, highly preferably a mammal, particularly preferably a human.
[0052] According to a further embodiment the invention relates to a method for the treatment of dermal injuries in a subject in need of such a treatment, wherein the damaged area of the skin is contacted with a compound of general formula (I)
[0000]
[0000] wherein Q, X 1 , X 2 , R 1 and R 2 of the formula are defined herein, e.g. above.
[0053] Preferably, the dermal wound of the method of the invention is a wound that extends into a layer under the epidermis.
[0054] Highly preferably the injury of the skin extends to all layers of the skin, including connective tissue, optionally connective tissue under the skin.
[0055] Highly preferably the dermal wound is associated with a chronic disease, wherein the chronic disease is preferably diabetes mellitus.
[0056] According to a preferred embodiment the compound of formula (I) is delivered to the injured skin in the form of a pharmaceutical composition. Highly preferably the composition is formulated for topical use. The pharmaceutical composition may be in the form of an ointment, cream, gel, spray, talcum, foam composition, patch, wound dressing, solution or suspension.
[0057] Highly preferably the composition is delivered to the injured skin surface 1 to 10 times daily, preferably 1 to 4, highly preferably 2 to 3 times daily.
[0058] Highly preferably the pharmaceutical composition described herein is used in the method of the invention.
SHORT DESCRIPTION OF THE FIGURES
[0059] Each Figure depicts median values with 25 th and 75 th percentiles. In each Figure, X means p<0.05 vs control, Da: dantrolene-treated group, control: saline-treated control group.
[0060] FIG. 1 : Macroscopic wound closure in the control- and dantrolene-treated groups.
[0061] FIG. 2 : Red blood cell velocity in the capillaries in the control- and dantrolene-treated groups.
[0062] FIG. 3 : Vessel diameters in the wound edges in the control- and dantrolene-treated groups.
[0063] FIG. 4 : Leukocyte adhesion in postcapillary venules in the control- and dantrolene-treated groups.
[0064] FIG. 5 : Blood flow of the wound area determined with Laser Doppler before and after application of dantrolene.
[0065] FIG. 6 : Extension of epithelialization zone (relative to initial diameter of the wound) in the control- and dantrolene-treated groups.
[0066] FIG. 7 : Dermal regeneration (relative to the dermis of the intact skin) in the control- and dantrolene-treated groups.
DETAILED DESCRIPTION OF THE INVENTION
[0067] The human skin consists of three layers: epidermis, dermis and subcutis. The epidermis is a multi-layer stratified squamous epithelium in which cells are continuously replenished from the stratum basale. Melanocytes are also found in the epidermis. The base of the dermis is a loose connective tissue containing vessels, nerve endings and skin appendages (e.g. hair follicles, sebaceous glands and sweat glands). Fatty tissue can be found among the tissue fibres of the subcutis. Herein, we define the top layer of the skin as the epidermis or the upper cell layers of the epidermis.
[0068] Dermal wounds, extending into the upper layers of the skin, preferably the layers under the epidermis, are frequent and according to the state of the art there is a need for further therapeutic approaches.
[0069] Dermal wounds, treated according to the method of the invention, may be superficial wounds affecting the epidermis and the directly underlying layer or moderately deep wounds penetrating to the dermis. Complex or deep dermal wounds affect not only the skin but may also extend to the muscle layer, nerves, bones and vessels under the skin. Concerning etiology, dermal wounds may originate in abrasion, slice, cutting, puncturing, crushing, laceration, biting, inadequate blood supply (e.g. atherosclerosis related ulcus), chronic diseases (e.g. foot ulcer due to diabetes), necrosis (e.g. decubitus), thermic harms (e.g. burns), and chemical challenges (e.g. acids) or other impacts. According to certain preferred embodiments, the dermal wound is not a thermic (e.g. burn) wound or a wound of the same mechanism or a wound requiring the same treatment as a burn wound. The term dermal wound as used herein may refer to both acute and chronic (difficult-to-heal) wounds. Preferably, the wound is a full thickness dermal wound. Full thickness wounds affect each layer of the skin, including connective tissue of the dermis and, optionally, that of the subcutis.
[0070] To our best knowledge, the background art does not offer any information regarding the effects of dantrolene or those of other compounds acting as antagonist of ryanodine receptors, described in the present invention, in the skin layers under the uppermost layer of the epidermis, and preferably in layers under the epidermis and tissue layers under the skin. It has not yet been clarified what kind of ryanodine receptors occur in the deeper layers of the skin, and therefore, no information is available on their distribution and physiological role in these tissues.
[0071] One skilled in the art can test the activity of an agent as a rynodine receptor antagonist without undue difficulties. Appropriate methods are described by Jaggar et al., 1998, Arendshorst & Thai, 2009, Denda et al., 2012 and other publications cited by the these authors. It is known that rynodine receptors play different roles in different organs and tissues. Although ryanodine receptors were found first in muscle tissue, it has been recognized that they appear in other tissues, as well. Their most extensively studied role is the connection of excitation and contraction, but they can be found in non-excitatory cells, too. Ryanodine receptor type 1 (RyR-1) is characteristic of striated muscle, type 2 (RyR-2) can be found in cardiac muscle but has been described in Langerhans islets, too. Ryanodine receptors type 1 and 3 were proved to be present in leukocytes. Ryanodine receptor type 3 (RyR-3) was first identified in the mammalian brain, but according to the present knowledge its occurrence may be considered universal, it can be found in the skin, striated muscle, smooth muscle and leukocytes although at lower quantities and its role is not fully clarified. RyR-1 and RyR-2 are also expressed in the brain. However, the pattern of their expression is different. RyR-1 appears abundantly in Purkinje cells of the cerebellum, RyR-2 is expressed predominantly in the dentate gyrus while RyR-3 in the pyramid cells of hippocampus (Ca1 region), the basal ganglia and the olfactory bulb. All isoforms are present in smooth muscle cells (Kushnir et al., 2010).
[0072] Ryanodine affects the mechanism of contraction differently in striated muscle and cardiac muscle. In striated muscle, it induces contractions leading to tetanic spasms, while it may result in cardiac arrest via decreasing the contractility in the heart. Although both effects are based on calcium release, the activity of calcium-scavenging mechanisms are different in striated muscle and cardiac muscle.
[0073] It has been described that ryanodine receptors can be found in vessels of different caliber in several organs, e.g. in the kidney (Arendshorst & Thai, 2009), urether, spermatic duct, mesenteric artery (Borisova et al., 2009), striated muscle (cremaster muscle) (Westcott & Jackson, 2011) and the brain (Dabertrand et al., 2012). Ryanodine receptors influence the intracellular calcium level in the vascular smooth muscle hereby regulating vascular tonus. However, they may play a different role in different organs. Inhibition of ryanodine receptors was found to lead to vasoconstriction (Jaggar et al., 1998). However, inhibition of ryanodine receptors may soothe the existing vasoconstriction in the kidney (Arendshorst & Thai, 2009). Caffeine, which activates the ryanodine receptors, leads to vasoconstriction in cerebral and meningeal vessels (Dabertrand et al., 2012, Knot et al., 1998). Nutritive arteries of the muscle tissue display vasodilatation due to inhibition of ryanodine receptors (Westcott & Jackson, 2011).
[0074] A paper published by Denda et al. (Denda et al., 2012) and patent application JP 2011250728 reveal that dantrolene and 1,1-diheptyl-4,4bipyridinium-dibromide (DHBP), another known antagonist of ryanodine receptors, ameliorate transepidermal water loss in mice in which barrier function is impaired after tape stripping of the upper epidermis. The authors have shown by means of immunohistochemistry that ryanodine receptors are present on the keratinocytes. Furthermore, expression of all isotypes (at mRNA level) is more pronounced in differentiated keratinocytes. RyR-1 and RyR-2 are localized in the upper layer of the epidermis. Accordingly, the authors presumed that the promotion of barrier reconstruction induced by dantrolene and DHBP originates in the inhibition of ryanodine receptors.
[0075] As far as we know, no data are available concerning the role of ryanodine receptors on dermal circulation and their impact on dermal injuries affecting layers under the upper part of epidermis.
[0076] In our experiments, we have studied the effects of dantrolene on different parameters of wound healing. SKH-1 hairless male mice were used in the experiments. Full-thickness wound was made in a dorsal skin fold. The effects of dantrolene or saline (control group) on wound healing were monitored by means of photo documentation, intravital videomicroscopy (IVM) and laser Doppler flowmetry. The experimental setup was in accordance with the model described by Sorg et al. (Sorg et al., 2007). Wounds were treated daily either with dantrolene or with saline.
[0077] Unexpectedly, our findings have shown that dantrolene accelerated the wound closure and decreased the number of leukocyte-endothelial interactions. Another unexpected effect was that dantrolene increased blood flow in the wound edges, evaluation of IVM records revealed significantly higher vessel diameters in dantrolene-treated animals than in control ones. Higher red blood cell velocities were measured in the capillaries. Laser Doppler flowmetry unraveled considerably higher blood flow as compared to baseline values. This microcirculation-improving effect of dantrolene was detected in two different tissue layers which, in view of the above mentioned published data, was not predictable.
[0078] IVM visualized the dermal vessels of the wound edges and showed that application of dantrolene increases vessel diameters, while laser Doppler sensor was placed onto the basis of the wound and blood flow in the muscle layer of the skin fold's opposite side was monitored. This examination showed elevated blood flow in the muscle.
[0079] Macroscopic wound closure was assessed by evaluation of photographs with a special software. Histology was used for characterization of epithelialization and dermal regeneration. Macroscopic wound closure reached nearly 100% in both groups. Rate of wound closure in the dantrolene-treated group was significantly higher on days 4, 8 and 12 than in the control group. Faster dermal regeneration induced by dantrolene is an unexpected result, because no information was available previously on regenerative or any other effects of dantrolene and/or ryanodine receptors in the lower layers of the skin. Ryanodine receptors mediate diverse effects in different tissues and the same ligands may induce distinct effects on different isoforms. Thus, effects of dantrolene on wounds penetrating into the deeper layers of the skin were not predictable for one skilled in the art prior to the experiments.
[0080] Based on our experiments, dantrolene exerts its beneficial effects through the vasculature and microcirculation of the dermis and the muscle layer. Although based on the findings described in patent application JP 2011250728 and of Denda and co-workers (Denda et al., 2012), the effect of dantrolene to the barrier function and regeneration of the epidermis could have been speculated, no patent (application) or manuscript describes the effect of dantrolene—or any other ryanodin-antagonist—on the circulation of neighboring vessels of wounds. Hence, this effect of dantrolene and its role in wound healing are novel and unforeseen results of our experiments.
[0081] The composition useful for wound healing referred to in patent application JP 2011250728 contains dantrolene, but based on its description the skilled artisan would have not deducted the conclusion which is described herein. The composition described in patent application JP 2011250728 is a muscle relaxant, which is used against inflammation, but not directly for the purpose of wound healing, although it was applied on skin wounds, the healing of which was depending on inflammatory processes, too.
[0082] Dantrolene—like other muscle relaxants described in patent application JP 2011250728—reduces inflammation through its muscle-relaxant effect by inhibiting the post-injury muscle control. However, in the present invention healing of skin wounds where the muscle control has no significance, is facilitated, since in the experimental model we used not only the upper and middle layer of skin tissue but the muscle layer below were removed as well. Therefore, according to the present invention, the effect of dantrolene on wound healing cannot be explained by its muscle relaxant effect.
[0083] In our experiments, excised wound was formed, the healing tendency of which differs from combustion wounds disclosed in JP 2007308403. Reducing inflammation, such as by the use of steroids, is recommended in case of minor combustion wounds, while in wounds of other origin steroids worsen healing tendency. Accordingly, reducing inflammation is not obviously results in improved wound healing.
[0084] Based on our experimental results, we may rightly assume that dantrolene will exert the same effect on wound healing in case of wounds similar to those in the above described experiments, such as diabetes mellitus and cardiovascular failure-related slow healing and chronic wounds. In support of our hypothesis we have designed the following experiment: application of dantrolene to promote wound healing in a skin fold chamber model after inducing diabetes by streptozotocin in mice.
[0085] Diabetes is induced with intraperitoneal (ip) injections of streptozotocin (5×50 mg/kg) according to literature data (Lee et al., 2014, Langer et al., 2002). After 5 weeks, the blood glucose content is measured and animals with 16.6 and 33.2 mmol/L glucose level are enrolled to the experiment. Wounds of standard size are made on the dorsal part of the ear. Wound healing will be investigated according to the methods described in the examples and mentioned above.
[0086] The pharmaceutical composition according to the invention may be used as a topical formulation. The formulation may be e.g. an ointment, cream, gel, talcum, foam composition, patch, wound dressing (such as a hydrogel, film bandage, mesh combined with alginate, impregnated with a cream), solution or suspension. Administration may be as usual to the applied formulation or different; e.g. an ointment may be spread to the skin in a thin layer once or multiple times daily, a solution may be dripped into the wound once or multiple times a day to wet the wound, a patch or wound dressing may be changed to cover the wound multiple times a day or week.
[0087] The concentration of the active agent in the pharmaceutical composition according to the invention depends on the formulation and the indication for application. It might be e.g. 1 to 100 mg/kg for a cream, 1-100 mg/ml or 1 to 1000 μM or preferably 10 to 500 μM for a solution.
[0088] Treating dermal wounds and determining the method of treatment in the light of the active agent and its effect is implicit in the knowledge of one skilled in the art. Further information regarding the treatment of dermal wounds is to be found in Cathy Thomas Hess “Clinical Guide to Skin and Wound Care” 7. ed. 2012, and Avi Shai and Howard I. Maibach “Wound Healing and Ulcers of the Skin—Diagnosis and Therapy—The Practical Approach” 2005, and: “A nem gyógyuló (krónikus) börsebek ellátásának elöirányzott irányelve.” A Börgyógyász Szakmai Kollégium jóváhagyásával készült irányelv 2011. átdolgozott formája. (“Guidelines to the therapy of non-healing (chronic) dermal wounds”. Revised version of the Guidelines (2011) approved by the Hungarian College of Dermatology.
EXAMPLES
Example 1
The Effects of Dantrolene on the Healing of Full-Thickness Dermal Wounds in Mice
[0089] The experiments were performed on male SKH-1 hairless mice of our own rearing (body weight: 36-44 g). Procedures and protocols were approved by the competent authorities (license number: V./145/2013.). Only healthy animals free of any type of injury were used, mice with any sign of disorders were discarded. Prior to the interventions the animals were anesthetized with a mixture of ketamine (Sigma) (90 mg/kg) and xylazine (Sigma) (25 mg/kg) administered intraperitoneally. A skin fold was formed in the dorsal region and was fixed with two symmetrical, fenestrated titanium plates (IROLA GmbH, Schonach, Germany) according to the description of Sorg et al. (Sorg et al., 2007).
[0090] Interventions and Treatments:
[0091] In the midline of the dorsal region two holding stitches were placed in order to form a skin fold. This skin fold was sandwiched by two symmetrical, fenestrated titanium plates. The plates were fixed with sutures, bolts and nuts. On one side of the skin fold, a circular full-thickness wound was made by removing the tissue down to muscle layer of the other side (the diameter of the wound was 4 mm while those of used for Laser-Doppler flowmetry came to 11 mm). The wound was covered with a glass coverslip incorporated into the window of the titanium frame. The glass was removed for the duration of treatments and measurements only. In the control group (n=6), the wounds were treated with 100 μL of sterile saline once a day while in the dantrolene-treated group (n=6) 100 μL of a solution containing the sodium salt of dantrolene (100 μM) was applied to the wound once a day (the salt was dissolved in sterile saline). The observation period took 20 days (according to our previous results this is the time period needed for approximately 100% closure of wounds of 4 mm).
[0092] Examinations:
[0093] Macroscopic wound closure. Photographs of the wounds were taken immediately after surgery and on days 4, 8, 12, 16 and 20. Circumstances of photographing were standardized (same light sources and distances). The images were evaluated with a software developed by our working group (DermAssess©). This software is an accessory function to the ImageJ software and enables the determination of color intensity (Eros et al., 2014) and the area measurement after calibration. Decrease in the wound area relative to the baseline value is given as percentage.
[0094] Intravital videomicroscopy (IVM). Microcirculation of the wound edges was monitored by means of IVM on days 4, 8 and 12. After anesthesia, 80 μL of a solution of fluorescein-isothyocyanate (FITC) labeled dextrane (2%) and also 80 μL of a solution of rhodamine-6G was administered retrobulbar. These contrast materials allow us to visualize microcirculation and leukocyte-endothelial interactions at the appropriate wavelengths. Video records of the microcirculation were evaluated off-line with Pictron IVM software. Red blood cell velocity (RBCV) was determined in the capillaries, the diameter of each vessel in the evaluated fields-of-view was measured (only diameters above 6 μm were considered) and sticking leukocytes were counted in the postcapillary venules (this parameter is relative to the area of the vessel wall and is given as cell/μm2).
[0095] Laser-Doppler flowmetry. In a further group (n=6), the animals were anesthetized on day 1 after wound creation. The sensor of the Laser-Doppler equipment was placed onto the wound. The sensor was removed after 10 minutes of measurement and 200 μL of dantrolene solution was applied to the wound. Another measurement was performed 10 minutes later.
[0096] Histology. On days 4 and 20 groups of control- and dantrolene-treated animals were sacrificed, the wounds were then excised, fixed in a solution of formaldehyde, embedded in paraffin and stained with hematoxylin and eosin. The Pannoramic Viewer software was used for the evaluation. Zone of epithelialization was defined as the extension of epithelial regeneration measured from the wound edges and given as percentage relative to the initial diameter of the wound. Dermal regeneration was determined, too (thickness of dermal connective tissue was measured within the wound area and was given as percentage relative to that of determined in the intact skin).
[0097] Statistical Analysis of the Results
[0098] Control- and dantrolene-treated groups were compared with the Mann-Whitney test and p<0.05 was considered statistically significant.
[0099] Results
[0100] Macroscopic wound closure. This parameter reached nearly 100% in both groups by day 20. On days 4, 8, and 12, the rate of wound closure in dantrolene-treated groups was significantly higher than in control group. On day 16, no difference was found between the groups ( FIG. 1 ).
[0101] RBCV in the capillaries. RBCV of dantrolene-treated animals was found be higher at all times of measurements (days 4, 8 and 12) than in control group ( FIG. 2 ).
[0102] Vessel diameters at the wound edges. Vessel diameters, determined at the wound edges of mice exposed to dantrolene, were considerably higher than those in the control group at corresponding times ( FIG. 3 ).
[0103] Sticking leukocytes in the postcapillary venules. Concerning leukocyte-endothelial interactions, said parameter was assessed as an indicator of inflammation. Our results revealed that application of dantrolene significantly decreased the number of sticking leukocytes on days 4 and 8. The difference on day 12 was not statistically significant ( FIG. 4 ).
[0104] Blood flow in the wound area. Laser Doppler flowmetry showed significant elevation in blood flow after dantrolene treatment ( FIG. 5 ).
[0105] Extension of epithelialization zone. Epithelialization determined with routine histology (zone of epithelialization) was more extended in dantrolene-treated mice than in control ones on day 4 ( FIG. 6 ).
[0106] Dermal regeneration. On day 4, said parameter was more expressed in animals receiving dantrolene than in control group ( FIG. 7 ).
Example 2
Effect of Dantrolene on the Healing of Diabetic Wounds
[0107] The experiments will be performed on 12-15-week-old SKH-1 hairless mice of our own rearing (minimal weight: 30 g). Procedures and protocols were approved by the competent authorities (license number: V./145/2013.). Appropriate temperature (24+2° C.), 12 h dark-light cycles and free access to standard laboratory chow and water will be provided. Only healthy animals, free of any type of injury will be used, mice with any sign of disorders (except diabetes mellitus) will be discarded.
[0108] Interventions and Treatments:
[0109] According to recent data, diabetes mellitus can be induced with Streptozotocin (50 mg/kg intraperitoneally injected daily for 5 days) (Lee et al., 2014). 5 weeks after the induction of diabetes, the blood glucose level will be determined. Animals with blood glucose levels between 16.6 and 33.2 mmol/l will be accepted for the study (Langer et al., 2002). Prior to the interventions the animals will be anesthetized with an intraperitoneally administered mixture of ketamine (90 mg/kg) and xylazine (25 mg/kg). The ear will then be gently stretched. On the dorsal side of the ear, a circular area with a diameter of 2.5 mm will be marked. Using this mark, a full-thickness dermal layer will be excised down to the underlying cartilage by means of microsurgical scissors under a surgical microscope (Langer et al., 2002). The wound will be treated with a dantrolene-containing formulation (100 μM), while the control group will receive the vehicle, without the active agent. The observation period will take 15 days.
[0110] Examinations.
[0111] Macroscopic wound closure.
[0112] Photographs will be taken on the wounds immediately after surgery and on days 4, 7, 12, and 15. Circumstances of photographing will be standardized (same light sources and distances). The images will be evaluated with a software developed by our working group (DermAssess©). This software is an accessory function to the ImageJ software and enables the determination of color intensity (Eros et al., 2014) and the area measurement after calibration.
[0113] Intravital videomicroscopy (IVM): Microcirculation of the wound edges will be monitored by means of IVM on days 4, 7 and 12. After anesthesia, 80 μL of a solution of fluorescein-isothyocyanate (FITC) labeled dextrane (2%) and also 80 μL of a solution of rhodamine-6G will be administered retrobulbar. These contrast materials allow us to visualize microcirculation and leukocyte-endothelial interactions at the appropriate wavelengths. Video records of the microcirculation will be evaluated off-line with Pictron IVM software. Red blood cell velocity (RBCV) will determined in the capillaries, the diameter of each vessel in the evaluated fields-of-view will be measured (only diameters above 6 μm will be considered) and sticking leukocytes will be counted in the postcapillary venules (this parameter is relative to the area of the vessel wall and is given as cell/μm2).
[0114] Histology: Histology. On day 15 animals will be sacrificed, the wounds will then be excised, in order to be fixed in a solution of formaldehyde, embedded in paraffin and stained with hematoxylin and eosin. The Pannoramic Viewer software will be used for the evaluation. Zone of epithelialization will be defined as the extension of epithelial regeneration measured from the wound edges and given as percentage relative to the initial diameter of the wound.
REFERENCES
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Denda S, Kumamoto J, Takei K, Tsutsumi M, Aoki H, Denda M: Ryanodine receptors are expressed in epidermal keratinocytes and associated with keratinocyte differentiation and epidermal permeability barrier homeostasis. J Invest Dermatol 2012; 132: 69-75.
Kushnir A, Betzenhause M, Marks A R. Ryanodine Receptor Studies Using Genetically Engineered Mice. FEBS Lett 2010; 584(10):1956-1965.
Balschun D, Wolfer D P, Bertocchini F, Barone V, Conti A, Zuschratter W, Missiaen L, Lipp H P, Frey J U, Sorrentino V. Deletion of the ryanodine receptor type 3 (RyR3) impairs forms of synaptic plasticity and spatial learning. EMBO J. 1999; 18:5264-73
Zucchi R, Ronca-Testoni S. The Sarcoplasmic Reticulum Ca 2+ Channel/Ryanodine Receptor: Modulation by Endogenous Effectors, Drugs and Disease States. Pharmacol Rev. 1997 (49):1-52
Arendshorst W J, Thai T L: Regulation of the renal microcirculation by ryanodine receptors and calcium-induced calcium release. Curr Opin Nephrol Hypertens 2009; 18:40-49.
Borisova L, Wray S, Eisner D A, Burdyga T: How structure, Ca signals, and cellular communications underlie function in precapillary arterioles. Circ Res 2009; 105:803-810.
Westcott E B, Jackson W F: Heterogeneous function of ryanodine receptors, but not IP 3 receptors, in hamster cremaster muscle feed arteries and arterioles. Am J Physiol Heart Circ Physiol 2011; 300:H1616-H1630.
Dabertrand F, Nelson M T, Brayden J E: Ryanodine receptors, calcium signaling, and regulation of vascular tone in the cerebral parenchymal microcirculation. Microcirculation 2012; 20:307-316.
Hess, Cathy Thomas “Clinical Guide to Skin and Wound Care” 7. kiad. 2012
M, Stevenson A S, Lederer W J, Knot H J, Bonev A D, Nelson M T: Ca 2+ channels, ryanodine receptors and Ca 2+ -activated K + channels: a functional unit for regulating arterial tone. Acta Physiol Scan 1998; 164:577-587.
Dabertrand F, Nelson M T, Brayden J E: Acidosis dilates brain parenchymal arterioles by conversion of calcium waves to sparks to activate BK channels. Circ Res 2012; 110:285-294.
Knot H J, Standen N B, Nelson M T: Ryanodine receptors regulate arterial diameter and wall [Ca 2 ] in cerebral arteries of rat by membrane potential and intravascular pressure. J Physiol 1998; 508(Pt I):211-221.
[0128] Shai Avi és Maibach Howard I. “Wound Healing and Ulcers of the Skin—Diagnosis and Therapy—The Practical Approach” 2005
[0129] Sorg H, Krueger C, Vollmar B: Intravital insights in skin wound healing using the mouse dorsal skin fold chamber. J Anat 2007; 211:810-818.
www.ogyi.hu/kiseroirat/ah/ah_0000015827_20090323104723.doc Harrison G C: Control of the malignant hyperpyrexic syndrome in MHS swine by dantrolene sodium. Br J Anaesth 1975; 47:62-65. Erös G, Kurgyis Z, Németh I B, Csizmazia E, Berkó S, Szabó-Révész P, Kemény L, Csányi E: The irritant effects of pharmaceutically applied surfactants. J Surfact Deterg 2014; 17(1):67-70. Lee E, Kim D Y, Chung E, Lee E A, Park K S, Son Y: Transplantation of cyclic stretched fibroblasts accelerates the wound-healing process in streptozotocin-induced diabetic mice. Cell Transplant 2014; 23:285-301. Langer S, Born F, Breidenbach A, Schneider A, Uhl E, Messmer K: Effect of C-peptide on wound healing and microcirculation in diabetic mice. Eur J Med Res 2002; 7:502-508.
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The invention relates to the use of pharmaceutical compositions containing as the active agent a compound of formula I in the treatment of dermal wounds. The compositions may be used for the promotion of healing of wounds affecting the deeper layers under the epithelium, including dermal- and sub dermal connective tissue, being cut, punctured, sliced wounds or originating in insufficient tissue perfusion, chronic diseases or other harms. The compositions are formulated for local application and may comprise other active agents contributing to wound healing in addition to a compound of formula (I).
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation-in-Part application of U.S. application Ser. No. 11/325,533 filed Jan. 5, 2006. Priority is claimed based on U.S. application Ser. No. 11/325,533 filed Jan. 5, 2006, which claims the priority of Japanese Patent Application No. 2005-001583 filed on Jan. 6, 2005, all of which is incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a semiconductor nanoparticle having high luminescence properties and a method for synthesizing the same. Moreover, the present invention relates to a fluorescent reagent and an optical device comprising such semiconductor nanoparticle.
[0004] 2. Background Art
[0005] Semiconductor nanoparticles with particle sizes of 10 nm or less are located in the transition region between bulk semiconductor crystals and molecules, so that they exhibit physicochemical properties different from those of either bulk semiconductor crystals or molecules. In such region, the degeneracy of energy bands that is observed in bulk semiconductors is removed and the orbits become discrete, so that a quantum size effect appears in which the energy width of the forbidden band changes depending on particle size. According to the appearance of the quantum size effect, the energy width of the forbidden band of a semiconductor nanoparticle decreases or increases in response to an increase or decrease of particle size. This change of the energy width of the forbidden band affects the fluorescence properties of the particle in question. A particle that has a smaller particle size and wider forbidden band energy width tends to have a shorter a fluorescent wavelength, while a particle that has a larger particle size and a narrower forbidden band energy width tends to have a longer fluorescent wavelength. That is, it is possible to create a desired fluorescent color by controlling particle size. In addition to the properties described above, semiconductor nanoparticles have high durability against excitation lights, etc., and a region which can be excited widely extends more towards the shorter wavelengths than the fluorescent wavelength, so that simultaneous excitation of multiple fluorescent colors is also possible by using a single excitation light source. Thus, semiconductor nanoparticles serving as fluorescent material are gaining significant attention. Specifically, the fields related to biotechnology and to optical device technology are listed as fields in which semiconductor nanoparticles have been used actively, and further applications are expected in the future.
[0006] In order to use semiconductor nanoparticles serving as fluorescence material, it is desired that such particles have fluorescence properties in which the fluorescence spectrum has a waveform with a narrow and sharp full width half maximum (FWHM). Thus, it is necessary that the band gap fluorescence properties in response to the forbidden band widths of the semiconductor nanoparticles are made effective. However, even if a prepared bulk particle has a monodisperse particle size, such particle per se does not exhibit sufficient band gap fluorescence properties. As a reason for this, the presence of the energy level existing mainly at the surface site of the semiconductor nanoparticle is mentioned, and, since the energy level exists in the forbidden band inside the particle, it has been thought that the band gap fluorescence properties are inhibited. Due to the reasons mentioned above, the inactivation of the aforementioned energy level and the obtaining of the band gap fluorescence have become significant subjects.
[0007] A method for providing a solution to this subject relates to a (CdSe)ZnS semiconductor nanoparticle, which has a so-called core-shell type structure. The aforementioned method involves obtaining high luminescence properties by coating the semiconductor nanoparticle (CdSe) with a second semiconductor material (ZnS), which has a wider forbidden band width than that of the particle, and removing the energy level in the forbidden band of the particle, thereby making the band gap fluorescence properties effective. (JP Patent Publication (Kohyo) No. 2001-523758 A and J. Phys. Chem. B. 101:9463 (1997))
[0008] In addition, by achieving particle size monodispersion in an aqueous solution and carrying out particle surface reforming, inventors have been studying a method for making band gap fluorescence effective. As a result of intensive studies carried out by the inventors, a method for obtaining semiconductor particles having commercially adequate fluorescence properties has been developed, in which semiconductor nanoparticles synthesized by a size-selective photoetching technique are treated in a refining process, the particles are subjected to surface reforming using sodium hydroxide or amine-ammonium compounds, and the energy levels at the particle surfaces are made inactive by arranging the electron-releasing groups on the surfaces, such that the band gap fluorescence properties are made effective. Moreover, by coating the obtained nanoparticles with organic compounds such as one composed of amphiphilic molecules, we succeeded in obtaining semiconductor nanoparticles having improved chemical durability. According to a series of these methods, synthesis of semiconductor nanoparticles that have high luminescence properties was realized by using a safe and simple technique in an aqueous solution. The nanoparticles per se have sufficient durability. In addition, high durability can be imparted to them by allowing preferably usable organic compounds, such as amphipathic molecules, to bind to each other. However, for the purpose of synthesizing high-functional semiconductor nanoparticles by a more convenient method, the inventors have arrived at the present invention.
SUMMARY OF THE INVENTION
[0009] The inventors have invented a surface treatment, such as an OH coating or ammonia treatment, as a surface reforming technique for semiconductor nanoparticles. However, semiconductor nanoparticles that have been subjected to a surface treatment, such as an OH coating or ammonia treatment, do not have sufficient durability against external factors, typically including pH. It has been an objective to solve the aforementioned problems.
[0010] In order to protect semiconductor nanoparticles from the aforementioned external factors, the inventors have attempted a method of coating obtained nanoparticles with organic material. Further, the inventors have conducted studies of semiconductor nanoparticles having chemical durability and showing high luminescence properties. When semiconductor nanoparticles are utilized for bio-related applications, it is preferable to modify the surfaces of such semiconductor nanoparticles with a functional group such as a carboxyl group. Also, it is necessary to modify semiconductor nanoparticles so as to improve the industrial availability thereof.
[0011] The inventors found that semiconductor nanoparticles exerting high luminescence properties can be obtained by applying surface reforming to semiconductor nanoparticles, and modifying the semiconductor nanoparticles with a functional group-containing polymer, thereby allowing the polymer to form a crosslink via a crosslinking agent.
[0012] That is, firstly, the present invention is an invention of a semiconductor nanoparticle exerting high luminescence properties, which is modified with a functional group-containing polymer that electrostatically binds to the semiconductor nanoparticle.
[0013] Preferably, electron-releasing groups are arranged on the surface of the semiconductor nanoparticle, and the polymer electrostatically binds to the outside of the electron-releasing groups. Preferably, the functional group-containing polymer electrostatically binds to the surface of the semiconductor nanoparticle, and the modifying groups of the functional group-containing polymer form a crosslinking bond via a crosslinking agent.
[0014] Preferably, specific examples of functional groups of the functional group-containing polymer include, but are not limited to, one or more functional groups selected from the group consisting of —COOH, —OH, —NH 2 , —SH, —OCN, —CNO, —CHO, —CH═O, —CH═CH 2 , and —C≡CH, so that various types of crosslinking reactions can be involved.
[0015] The functional group-containing polymer may directly bind to the surface of a semiconductor nanoparticle or bind thereto via a semiconductor nanoparticle-coating compound.
[0016] Preferably, specific examples of the crosslinking bond include one or more bonds selected from the group consisting of an ester bond, an amide bond, an imide bond, an ether bond, a urethane bond, a sulfide bond, a polysulfide bond, a carbonate bond, a thiol bond, a thioester bond, and a thiourethane bond. The crosslinking bond comprises a crosslink that results from carbon-carbon double bond or carbon-carbon triple bond polymerization.
[0017] In preferred examples, the functional group-containing polymer is polyacrylic acid and the crosslinking agent is alkylene diamine.
[0018] Preferably, examples of the electron-releasing group include at least one group selected from the group consisting of —OR, —OCH 2 R, —OCOCH 2 R, —NHR, —N(CH 2 R) 2 , —NHCOCH 2 R, —CH 2 R, and —C 6 H 4 R, where R is hydrogen, a substituted hydrocarbon group, or an unsubstituted hydrogen group. In addition, preferably, examples of the semiconductor nanoparticle surface-coating compound include one or more compounds selected from the group consisting of primary amines (R 1 NH 2 ), in particular alkyl amines having more than 7 carbons, more preferably C 8-24 alkyl amines, secondary amines (R 1 R 2 NH), tertiary amines (R 1 R 2 R 3 N), and quaternary ammonium compounds (R 4 R 5 R 6 R 7 N + ), where R 1 to R 7 are each hydrogen, a substituted hydrocarbon group, or an unsubstituted hydrogen group and R 1 to R 7 preferably comprise a substituent at a terminal opposite to an amino group or ammonium group.
[0019] Preferably, specific examples of the semiconductor nanoparticle material include, but are not limited to, one or more materials selected from the group consisting of ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdMnS, CdSe, CdMnSe, CdTe, CdMnTe, HgS, HgSe, HgTe, InP, InAs, InSb, InN, GaN, GaP, GaAs, GaSb, TiO 2 , WO 3 , PbS, PbSe, MgTe, AlAs, AlP, AlSb, AlS, Ge, and Si. In addition, a semiconductor nanoparticle having a multilayer structure consisting of a core portion and a shell portion may be made of one or more member of the aforementioned group.
[0020] The particle size of the semiconductor nanoparticle of the present invention exhibits a deviation of less than 10% rms in diameter, thereby achieving monodispersion.
[0021] Moreover, the semiconductor nanoparticle of the present invention is characterized in that it emits light in a narrow spectrum range of less than 60 nm in terms of full width at half maximum (FWHM) upon being irradiated with excitation light.
[0022] Secondly, the present invention is an invention of a method for manufacturing a semiconductor nanoparticle, which comprises a process for allowing a functional group-containing polymer to electrostatically bind to the surface of the semiconductor nanoparticle, a process for causing functional groups of the polymer to form a crosslink via a crosslinking agent.
[0023] Specifically, the method comprises a process for arranging electron-releasing groups on the surface of a semiconductor nanoparticle by adding surface-treating material having one or more electron-releasing groups to the semiconductor nanoparticle, a process for allowing a functional group-containing polymer to electrostatically bind to the arranged electron-releasing groups, and a process for causing functional groups of the functional group-containing polymer to form a crosslink via a crosslinking agent.
[0024] As above, preferably, examples of functional groups of the functional group-containing polymer include, but are not limited to, one or more groups selected from the group consisting of —COOH, —OH, —NH 2 , —SH, —OCN, —CNO, —CHO —CH═O, —CH═CH 2 , and —C≡CH.
[0025] Preferably, examples of the crosslinking reaction include one or more reactions selected from the group consisting of an esterification reaction, an amidation reaction, an imidation reaction, an etherification reaction, an urethanation reaction, a sulfidation reaction, a polysulfidation reaction, a carbonate reaction, a thiolation reaction, a thioesterification reaction, and a thiourethanation reaction. A carbon-carbon double bond or carbon-carbon triple bond polymerization reaction is also effective for the formation of an organic layer as an outer shell of the semiconductor nanoparticle.
[0026] Particularly, in preferred examples, the functional group-containing polymer is polyacrylic acid and the crosslinking agent is alkylene diamine. Specifically, a semiconductor nanoparticle having further improved durability and a surface condition that is particularly preferable for bio-related applications is obtained by allowing a polymer such as polyacrylic acid to electrostatically bind to the surface of a semiconductor nanoparticle that has been coated with organic compounds or by surface reforming with the use of electric charges on the surface of the semiconductor nanoparticle, and further by allowing the polymer to form a crosslinking bond with another polymer with the use of ethylenediamine, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), or the like.
[0027] Preferably, examples of a surface-treating material that provides electron-releasing groups to a semiconductor nanoparticle surface include at least a pure metal, a metal compound, nitrogenated compounds selected from the group consisting of ammonia, amines, ammoniums, nitriles, and isocyanates, or oxygenated compounds selected from the group consisting of alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, and acid anhydrides.
[0028] Preferably, examples of the semiconductor nanoparticle-coating material include at least one material selected from the group consisting of primary amines (R 1 NH 2 ), secondary amines (R 1 R 2 NH), tertiary amines (R 1 R 2 R 3 N), and quaternary ammonium compounds (R 4 R 5 R 6 R 7 N + ), where R 1 to R 7 are each hydrogen, a substituted hydrocarbon group, or an unsubstituted hydrocarbon group, and R 1 to R 7 preferably comprise a substituent at a terminal opposite to an amino group or ammonium group.
[0029] Thirdly, the present invention is an invention regarding semiconductor nanoparticle applications, and the invention relates to a fluorescent reagent and an optical device.
[0030] According to the present invention, semiconductor nanoparticles that are available for use in industries related to bio-applications can be synthesized. Further, reagents that are relatively safer than those used in existing methods can be used, so that a synthesis method that is performed under safe reaction conditions can be selected. Thus, semiconductor nanoparticles that are suitable for mass synthesis and the like can be produced in a more industrially adequate manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 shows absorbance and fluorescence spectra of a NH 3 surface reformed semiconductor nanoparticle and a semiconductor nanoparticle obtained by adding an ammonium compound to an aqueous solution containing the surface reformed semiconductor nanoparticle.
[0032] FIG. 2 shows a schematic diagram of a semiconductor nanoparticle obtained by adding an ammonium compound to a NH 3 surface reformed semiconductor nanoparticle.
[0033] FIG. 3 shows absorbance and fluorescence spectra of a semiconductor nanoparticle obtained by adding an ammonium compound to a NH 3 surface reformed semiconductor nanoparticle.
[0034] FIG. 4 shows a schematic drawing of semiconductor nanoparticles comprising a crosslink formed with polyacrylic acid and ethylenediamine.
[0035] FIG. 5 shows absorbance and fluorescence spectra of a semiconductor nanoparticle comprising a crosslink formed with polyacrylic acid and ethylenediamine.
[0036] FIG. 6 shows transmission electron microscope (TEM) pictures of a semiconductor nanoparticle comprising a crosslink formed with polyacrylic acid and ethylenediamine.
[0037] FIG. 7 shows absorbance and fluorescence spectra together with durability of a semiconductor nanoparticle synthesized according to the example 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] The preferred embodiments for carrying out the present invention will be described below.
EXAMPLES
[0000] (In the Case of using a Size Selective Photoetching Technique)
[0039] First, 61.8 mg of sodium hexametaphosphate (0.1 mmol) and 84.4 mg of cadmium perchlorate (0.2 mmol) were added to a container filled with 1000 ml of 30° C. ultrapure water, 141.960 mg of disodium hydrogenphosphate (1 mmol) was added thereto, and then this solution was stirred for 30 minutes in a container that was sealed while nitrogen was bubbled thereinto. After that, 4.96 cm −3 (1 atm, 25° C.) of hydrogen sulfide gas was added to the aforementioned container to result in equal amounts of S 2− and Cd 2+ while the container was strongly shaken, and the solution was agitated for several hours at room temperature. At this time, the color of the solution changed from optically clear colorless to optically clear yellow. Moreover, after removing unreacted hydrogen sulfide in the solution by bubbling nitrogen into the solution, oxygen bubbling was carried out for 10 minutes and 25.7 mg of methyl viologen (0.1 mmol) was added to the solution. Here, the aforementioned solution was irradiated with monochromatic light using a laser, etc. or light from a mercury vapor lamp that had passed through a color filter to control the particle size using a size selective photoetching technique. Then, after the aforementioned solution was agitated for 30 minutes while nitrogen was bubbled into the solution, 50 μl of 3-mercaptopropionic acid was added thereto and the resultant was agitated for one night under shading.
[0000] (In the Case of not using a Size Selective Photoetching Technique)
[0040] First, 61.8 mg of sodium hexametaphosphate (0.1 mmol) and 84.4 mg of cadmium perchlorate (0.2 mmol) were added to a container filled with 1000 ml of 30° C. ultrapure water, 28.392 mg of disodium hydrogenphosphate (0.2 mmol) and 95.984 mg of sodium dihydrogenphosphate (0.8 mmol) were added thereto, and then this solution was stirred for 30 minutes in a container that was sealed up while nitrogen was bubbled thereinto. After that, 4.96 cm −3 (1 atm, 25° C.) of hydrogen sulfide gas was added to the aforementioned container to result in equal amounts of S 2− and Cd 2+ while the container was strongly shaken, and the solution was agitated for several hours at room temperature. Moreover, after removing unreacted hydrogen sulfide in the solution by bubbling nitrogen into the solution, 50 μl of 3-mercaptopropionic acid was added to the solution, followed by agitation for one night under shading.
[0041] 1000 ml of solution prepared by either method described above was ultra-filtered and concentrated to several milliliters so as to remove methyl viologen, hexametaphosphoric acid, unreacted thiol compound, and ions, etc. dissolved upon photoetching from the aqueous solution, such that a solution containing semiconductor nanoparticles having surfaces modified with a pure thiol compound was prepared. Then, it was ultra-filtered by adding pure water and refined by repeating this process several times. Thereafter, a surface reforming treatment was performed by using the solution, which was finally concentrated to several milliliters.
[0042] The refined thiol-modified semiconductor nanoparticle solution obtained as described above was diluted by using 0.1 M NH 3 aq. so as to have an absorbance of 0.5, and surface treatment was carried out by allowing it stand for several days under irradiating fluorescent light. Accordingly, a semiconductor nanoparticle solution having high luminescence properties was obtained. The obtained solution was optically clear yellow and it had excellent luminescence properties. Fluorescence spectra from such time are shown in FIG. 1 .
[0043] A mixed solution made by adding tridodecylmethylammonium chloride to an organic solvent such as hexane to a concentration of 1 mg/ml with respect to the solvent was added to the aforementioned surface reformed semiconductor nanoparticle solution in an amount such that it accounted for 1/10 of the amount of the solution. Or, alternatively, a mixed solution made by adding trioctadecylmethylammonium bromide to an organic solvent to a concentration of 2 mg/ml with respect to the solvent was added to the surface reformed semiconductor nanoparticle solution in an amount such that it accounted for 1/10 of the amount of the solution, and methanol was added thereto in an amount such that it accounted for ⅕ of the amount of the solution. Either one of these resulting solutions was strongly agitated for a certain time. As a result, it could be confirmed that the optically clear yellow part was transferred from the aqueous phase to the organic phase. Then, after performing a centrifugal separation, the aqueous phase and the organic phase were separated. The aforementioned recovered organic phase was diluted by adding an organic solvent such as hexane so as to result in the same absorbance as that of the aforementioned aqueous solution before transfer. The semiconductor nanoparticles transferred to the organic phase still maintained high luminescence properties. Fluorescence spectra from such time are shown in FIG. 1 .
Example 1
[0044] Nanoparticles perfectly dispersed into the organic solvent obtained as mentioned above were coated with amphipathic molecules. 10 ml of a solution in which nanoparticles had perfectly dispersed into the aforementioned organic solvent was put into a container such as a stoppered test tube or an eggplant shaped flask, etc. and was made to assume a membranous form on the inner wall of the container by evaporation. Then, the particles were dissolved again by adding 2 ml of solution in which dodecyltrimethylammonium chloride was dissolved in chloroform to a concentration of 5 mM, and the resulting solution was made to assume a membranous form again on the inner wall of the container by evaporation. Moreover, after removing residual chloroform by heating the container at 90° C., the particles were dissolved again by adding 2 ml of methanol. Then, methanol was removed by adding 10 ml of ultrapure water, followed by agitation for some time during heating to 90° C. Finally, an optically clear yellow solution could be obtained by performing centrifugal separation so as to remove the precipitation. A schematic drawing and optical spectra at this time are shown in FIGS. 2 and 3 , respectively.
[0045] Polyacrylic acid (average molecular weight: 5000) and ethylenediamine were added to the obtained optically clear yellow solution to concentrations of 0.1 mM and 1.5 mM therein, respectively, followed by agitation for some time. Further, hydrochloric acid 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide was added thereto to a concentration of 10 mM therein, followed by agitation for several days. Thereafter, the resultant was ultra-filtered so as to be refined. A schematic drawing, fluorescence spectra, and transmission electron microscope (TEM) pictures from such time are shown in FIGS. 4, 5 , and 6 , respectively.
[0046] Particle having further improved durability can be synthesized by arbitrarily selecting the types of surfactants and crosslinking agents for use, the types of solvents and methods for replacing the solvents, temperature conditions, etc.
Example 2
[0047] CdS nanoparticles perfectly dispersed into the organic solvent obtained as mentioned above (10 ml) were put into an eggplant shaped flask, and then hexane was removed by evaporation. 2 ml of chloroform was added and octadecylamine was added thereto to a concentration of 0.5 mM, and then, they were dissolved using ultrasonic wave. Further, the chloroform was removed by evaporation, and 2 ml of THF was added thereto for dissolving the nanoparticles again. Here, ultrasonic treatment may be used. Then, 10 ml of ultrapure water and a stirring bar were put into an eggplant shaped flask, and CdS nanoparticles dissolved in THF were rapidly poured thereto while agitated by the stirrer. The solution was dissolved by ultrasonic treatment, etc, only THF was removed by evaporation for obtaining a water solution, and then, the water solution was put into a centrifuge tube for removing precipitation by centrifugation. Thereby, water-soluble nanoparticles with amino groups arranged on the surfaces thereof were obtained.
[0048] 10 ml of the obtained solution and a stirring bar were put into an eggplant shaped flask, and 50 μl of 0.2 M-polyacrylic acid adjusted to pH 7 was added thereto, and agitated by the stirrer for one hour. 1 μl of ethylenediamine is added thereto and agitated by the stirrer for ten minutes, and then, 19.2 mg of WSC was added and further agitated by the stirrer overnight. In this case, the polyacrilic acids binding to the surfaces of the particles are crosslinked by ethylenediamine. When amine is used as amphipathic molecules to make the nanoparticles water-soluble, this amine also binds to the polyacrilic acids. This solution was put into the centrifuge tube for removing precipitation by centrifugation, and then, flow cleaning was carried out using ultrafiltration equipment of 50 ml cells. Although precipitation was produced under an acidic region, the obtained particles continued to maintain the same fluorescence property for more than one month under regions of pH 5 to 9 in pure water.
[0049] Each of the nanoparticles obtained according to either the example 1 or 2 has a carboxyl group exposed on the surface thereof. Such configuration is preferable for staining and labeling of biopolymers.
[0050] As described above, the present invention is not especially limited with respect to the material of particles, the types of surfactants and crosslinking agents for use, the types of polymers to be electrostatically bound, the types of solvents and methods for replacing the solvents, concentration and temperature conditions, etc. Further, characteristic improvements in dispersibility and durability can be realized by arbitrarily selecting these conditions, and the surface design of varying the types of functional groups to be exposed to the surface or the like can be flexibly performed. Furthermore, with the use of the method of the present invention, semiconductor particles having an entirely positively charged surface condition and those having a negatively charged surface condition can alternately be laminated on each other, so that the improvement of durability of the particles can be attempted. In addition, crosslinking using ethylenediamine was carried out in the Examples, while polymers used may contain a portion capable of being crosslinked. Further, in the present invention, particle size control is not particularly carried out. It is also possible to obtain fine particle sizes using an ultrasonic homogenizer, etc.; however, any particle size can be appropriate.
[0051] According to the present invention, it becomes possible to easily synthesize semiconductor nanoparticles that have high luminescence properties and excellent chemical stability. The semiconductor nanoparticles of the present invention can be used for fluorescent reagents and optical devices, etc. by utilizing such high luminescence properties.
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Semiconductor nanoparticles having high luminescence properties that are preferable for applications and uses of biotechnology are provided. With the use of electric charges on the surfaces of particles, the particles and selected polymers are allowed to electrostatically bind to each other, such that the surfaces of the particles are coated. The polymers are allowed to crosslink to each other, resulting in the improved durability of the particles. Further, functional groups contained in the polymers are exposed on the surfaces of the particles. Accordingly, semiconductor nanoparticles that are preferably utilized for applications such as staining and labeling of biopolymers have been synthesized.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to conductive polymers comprising silicon-containing polymers, such as polysilanes, poly(di-silanylenephenylenes) and the like, which are particularly useful as electrodes for batteries, solar cells and boxes for electromagnetic shields. The invention also relates to a process for preparing such polymers.
2. Description of the Prior Art
In recent years, it has been found that doping of polyacetylene with electron acceptors or electron donors results in a charge transfer forming reaction, thereby developing high electric conductivity based on the electron conduction. Attention has now been paid to conductive organic polymer compounds such as polyacetylene, polyphenylene, polypyrrole, polyaniline and polythiophene for use as materials capable of forming highly conductive films.
However, these organic polymer compounds are not molten or fused and are poor in shaping properties. Accordingly, the following problems are involved. Where these polymers are formed into films according to a vapor phase polymerization process or an electrolytic polymerization process, limitation is inevitably placed on the shape of the resultant film, which depends on the shape of a reactor container or an electrode. In addition, when doped with electron acceptors or electron donors, the polymers suffer considerable degradation, thus presenting problems with practical applications.
On the other hand, silicon-containing polymers contain silicon atoms, so that they are more metallic in nature and exhibit greater non-electron-localizing properties than those polymers containing carbon atoms. In addition, such polymers are highly resistant to heat, are flexible and have good thin film-forming properties, thus being very interesting polymers. However, few silicon-containing polymers have been known as having high conductivity. Only Ishikawa et al proposed highly conductive polymers wherein disilanylenephenylene polymers are doped with fluorine compounds such as SbF 5 , AsF 5 and the like (M. Ishikawa et al., J. Organometallics, 6, 1673 (1987); J. Organomet. Chem., 369, C18 (1989); Organometallics, 8, 2741 (1989); Macromolecules, 24, 2106 (1991)). However, SbF 5 , AsF 5 and the like are so toxic that they are undesirable to handle. Further, they necessitate a complicated doping procedure.
Therefore, studies have been made to dope ferric chloride (FeCl 3 ) which is less toxic and easier in handling than the fluorine compounds such as SbF 5 , AsF 5 and the like. For instance, Corriu et al proposed doping with FeCl 3 by mixing the polymer and FeCl 3 in a solution (R. J. Corriu et al., J. Organomet. Chem., 417, C50 (1991)). This procedure is a wet doping method which requires flammable solvents and has the problem that satisfactorily high electric conductivity cannot be imparted to the polymers.
SUMMARY OF THE INVENTION
An object of the present invention is to provide silicon-containing polymers which are imparted with high electric conductivity and good shaping properties.
Another object of the present invention is to provide silicon-containing polymers doped with ferric chloride whereby high electric conductivity is imparted thereto.
A further object of the present invention is to provide a method for preparing such silicon-containing polymers as mentioned above.
We have made intensive studies in order to achieve the above objectives. As a result, it has been found that silicon-containing polymers having Si--Si bonds or both Si--Si bonds and C--C multiple bonds in the main chain thereof are simply doped by a dry process wherein they are exposed to the vapor of ferric chloride, thereby obtaining conductive polymers having high electric conductivity and good shaping properties. More particularly, ferric chloride is initially heated and vaporized at normal pressures or under reduced pressure. When the film of a silicon-containing polymer is subjected to vapor phase doping of ferric chloride, it is readily doped thereby providing a conductive polymer film with high electric conductivity. The silicon-containing polymers having such a main chain as set out above are soluble in solvents and can be formed as a film or coating of a desired shape. This enables one to dope the polymer in the form of a desirably shaped film or coating. Ferric chloride used for the doping is low in toxicity and inexpensive, and it readily imparts electric conductivity to silicon-containing polymers at a high level. After doping, the polymers undergo little or no embrittlement and keep their inherent flexibility.
Hence, according to one embodiment of the present invention, there is provided a silicon-containing conductive polymer which comprises a silicon-containing polymer having Si--Si bonds or both Si--Si bonds and C--C multiple bonds in the main chain, and ferric chloride doped in the silicon-containing polymer through vapor phase doping.
According to another embodiment of the present invention, there is also provided a method for preparing a silicon-containing conductive polymer which comprises providing a film or coating of a silicon-containing polymer which has Si--Si bonds or both Si--Si bonds and C--C multiple bonds in the main chain, and subjecting the film or coating to vapor phase doping with ferric chloride. In order to create the vapor of ferric chloride, it is preferred to heat ferric chloride at normal pressures or under a reduced pressure at a temperature of 50° to 300° C.
In general, ferric chloride may be doped in silicon-containing polymers by several methods including (1) a wet doping method wherein the polymer is immersed in a solution of dissolved ferric chloride in an inert solvent, and (2) a simultaneous doping method wherein the polymer is dissolved in a solution of dissolved ferric chloride, from which a film or coating is formed thereby doping the polymer with the ferric chloride at the same time. In either doping method, the doping with ferric chloride brings about degradation of the silicon-containing polymer. This will entail gelation or decomposition of the polymer in a complicated manner. Additionally, high electric conductivity cannot be achieved. In contrast, the method of the present invention is free of these disadvantages, by which the polymers can be readily doped thereby attaining high electric conductivity.
The conductive polymers have good shaping properties and can be readily formed into highly conductive films or coatings. The condutive polymers are useful as a material for forming electrodes of batteries, solar cells and boxes for electromagnetic shields. Thus, the polymers have wide utility in the fields of the electric, electronic and communication industries.
DETAILED DESCRIPTION OF THE INVENTION
The silicon-containing polymers should be ones which have Si--Si bonds or both Si--Si bonds and C--C multiple bonds in the main chain. The silicon-containing polymer should preferably have the following general formula (1) or (2). ##STR1## wherein A is a group with multiple C--C bonds.
Examples of the group with multiple C--C bonds include ##STR2##
In the above formulae, each R independently represents a hydrogen atom or a substituted or unsubstituted monovalent organic group having 1 to 14, preferably 1 to 10 carbon atoms. Specific examples of the monovalent organic group include alkyl groups such as methyl, ethyl, propyl, butyl, hexyl and the like, aryl groups such as phenyl, tolyl, naphthyl, anthracenyl and the like, and heterocyclic ring-bearing alkyl groups such as carbazolylpropyl.
These silicon-containing polymers are not critical with respect to the weight average molecular weight and are generally in the range of 2,000 to 1,000,000, preferably 3,000 to 500,000. Therefore, "n" in formulae (1) and (2) should preferably be an integer which imparts the above weight average molecular weight to the silicon-containing polymers. In the silicon-containing polymer, the Si--Si bond should be provided in an amount of 50 to 100 mol %.
In order to obtain the conductive polymer of the invention, ferric chloride is heated at normal pressures or under a reduced pressure to vaporize the ferric chloride. The silicon-containing polymer is subjected to vapor phase doping in the vapor of the ferric chloride. As the vapor phase doping proceeds, the conductivity of the polymer increases rapidly. Finally, the conductivity is maintained at a given level, at which time the doping is completed.
The doping speed can be appropriately controlled by controlling the atmospheric temperature of the ferric chloride dopant and the partial pressure of the dopant in a container used for the doping. More particularly, the pressure is in the range of 0.001 to 760 mmHg and the temperature is in the range of 50° to 300° C. In view of the effective increase of the electric conductivity of the polymer, it is preferred that the pressure is in the range of 0.1 to 10 mmHg and the temperature is in the range of 50° to 200° C. If the pressure is lower than 0.001 mmHg, it takes a long time before reaching such a low pressure level, with poor economy. On the contrary, when the pressure exceeds 760 mmHg, the doping speed becomes very slow. This is because the boiling point of ferric chloride is 319° C. at normal pressures. When the temperature is lower than 50° C., the doping speed becomes low. When the temperature exceeds 300° C., the silicon-containing polymer film may degrade at the time of the doping.
Using the doping method of the invention, there can be obtained conductive polymers with high electric conductivity by a simple procedure wherein ferric chloride which is low in toxicity is used as a dopant without use of any flammable solvent.
It will be noted that in the practice of the invention, the starting silicon-containing polymer is usually employed in the form of a film or coating in order to facilitate uniform doping throughout the polymer.
The present invention is more particularly described by way of examples, which should not be construed as limiting the invention thereto. Comparative examples are also described. First, preparation of polysilane and poly(di-silanylenephenylene) is described.
SYNTHETIC EXAMPLE
Toluene was added to metallic sodium in a stream of nitrogen, followed by heating to 110° C. for dispersion under high speed agitation. While agitating, dichlorodiorganosilane or bis(chlorodialkylsilyl)benzene was gently dropped into the dispersion. The silicon compounds were each added in an amount of 1 to 1.05 moles per 2 moles of the metallic sodium. Agitation was continued over 4 hours until the starting material disappeared, thereby completing the reaction. After allowing to cool, the resulting salt was filtered and concentrated to obtain intended polysilane or poly (disilanylenephenylene).
EXAMPLES 1-11
The silicon-containing polymer (i.e. polysilane or poly(disilanylenephenylene) prepared in the Synthetic Example) was dissolved in tetrahydrofuran (THF) to make a 10% polymer solution. Separately, a four terminal unit was formed on a glass sheet by vacuum deposition of platinum to provide an electrode. The polymer solution was spin coated on the glass sheet and dried at a pressure of 2 mmHg at a temperature of 50° C., thereby forming a 1 μm thick thin film to obtain a sample for measurement of electric conductivity.
Ferric chloride was placed in the bottom of a dried, brown glass bottle container and the thin film was attached to the inside of the glass bottle. Thereafter, the glass bottle was connected to a vacuum pump and evacuated to a level of 4 mmHg, under which the ferric chloride at the bottom of the bottle was heated by means of a mantle heater. By the heating, the thin film was turned from transparent to blackish brown, simultaneously with a rapid increase of the electric conductivity. The conductivity was finally kept at a given level, at which the temperature of the sample reached as high as 150° C. At this stage, the vacuum pump was stopped and the heating was also stopped, followed by allowing the bottle to cool down to 25° C. and measurement of electric conductivity. The results are shown in Table 1.
It will be noted that the conductivity was measured by contacting the film on the glass sheet with the vapor of ferric chloride while monitoring the variation in DC resistance in relation to the time. After the resistance value was kept stable, the film was allowed to cool down to 25° C. The electric conductivity was determined from the resistance value.
TABLE 1______________________________________ conductivity after doping with FeCl.sub.3Example Silicon-containing Polymer (S/cm,No. [weight average molecular weight] at 25° C.)______________________________________1 phenylmethylpolysilane [46,000] 5.5 × 10.sup.-62 SiH group-containing 1.6 × 10.sup.-4 phenylmethylpolysilane (containing 6.5 mol % of SiH group) [24,000]3 dioctylpolysilane [120,000] 1.0 × 10.sup.-74 dibutylpolysilane [650,000] 2.2 × 10.sup.-105 (biphenylethyl)methylpolysilane 1.3 × 10.sup.-4 [8,500]6 CZ [3,600] 1.5 × 10.sup.-57 CZ/PS copolymer* (containing 16.7 2.6 × 10.sup.-5 mol % of carbazolylpropyl group) [207,000]8 (phenanthrenylpropyl)methyl- 7.7 × 10.sup.-6 polysilane [8,600]9 phenylmethyl side chain-bearing 3.3 × 10.sup.-4 polydisilanylenephenylene [27,000]10 dibutyl side chain-bearing 1.5 × 10.sup.-6 polydisilanylenephenylene [9,500]11 phenylmethyl side chain-bearing 5.0 × 10.sup.-4 polydisilanylenexylylene [6,900]______________________________________ *CZ: 3(N-carbazoyl) propyl methyl polysilane PS: phenylmethylpolysilane
COMPARATIVE EXAMPLES 1 & 2
Polysilane having a carbazolylisopropyl group at side chains (CZ) was provided as a silicon-containing polymer and dissolved in THF to make a 10% polymer solution. Separately, a 10% ferric chloride solution in THF was mixed with the polymer solution at ratios to the polymer indicated in Table 2, followed by allowing to stand. As a result, it was found that about one hour after the mixing, the mixtures were gelled.
A four terminal unit was formed on a glass substrate to provide an electrode. Immediately after mixing of the 10% ferric chloride solution in THF and the 10% polymer solution in THF, the mixture was spin coated onto the glass sheet and dried under conditions of a pressure of 2 mmHg and a temperature of 50° C., thereby forming a 1.0 μm thick thin film for use as a sample for measurement of electric conductivity (Comparative Examples 1 and 2). The results of the measurement are shown in Table 2 in which the results of Example 6 are also shown for comparison.
TABLE 2______________________________________ Amount of Electric dopant conductivity Film-forming (ratio by (S/cm conditions weight) at 25° C.)______________________________________Comparative wet process CZ/FeCl.sub.3 = 3.8 × 10.sup.-8Example 1 solvent: THF 1/0.333Comparative temperature: 25° C. CZ/FeCl.sub.3 = 4.7 × 10.sup.-8Example 2 pressure: 760 mmHg 1/0.666Example 6 dry process -- 1.5 × 10.sup.-5 temperature: 150° C. pressure: 2 mmHg______________________________________
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A conductive polymer comprises a silicon-containing polymer having, in the main chain thereof, Si--Si bonds or both Si--Si bonds and C--C multiple bonds, and ferric chloride doped in said polymer through vapor phase doping. A method for preparing such a conductive polymer is also described.
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BACKGROUND OF THE INVENTION
The present invention is directed to a warp knitting machine for diagonally layable warp threads. This machine is provided with a frame comprising the needle bed, a motor-driven main shaft, and a laying arrangement whose thread guides are movable across the breadth of the needle bed and back. A large number of weft threads are provided to the knitting machine from reserve spools.
Warp knitting machines of this type have been know for decades as Milanese machines. Since the thread guides for providing the warp threads (or a part of the warp threads) to the machine run on a circular path, the finished fabric contains warp threads which generally speaking run diagonally from one fabric edge to the other and back. The thread guides are constructed either as holes in a continuous band or as thread guides on displaceable individual carriers. They are able to carry out controlled movements with at rest positions and rearward displacement so that a patterning is achieved. The warp threads are provided from partial warp beams which lie over the laying arrangment and similarly over the circular path and have a circulation time equal to that of the lapping arrangement. The warp beams are small since otherwise problems will occur when they are moved on a circular path. Therefore, large changes are required of the partial warp beams, even when one works with thin threads.
Accordingly there is a need for a warp knitting machine of the aforegoing type which requires less use of new thread provision bodies and which permits the use of whatever threads desired, particularly thicker threads.
SUMMARY OF THE INVENTION
In accordance with the disclosed embodiments demonstrating features and advantages of the present invention, there is provided a warp knitting machine for diagonally laying warp threads. The machine has a frame secured to rotate about a fixed axis and a needle bed mounted on the frame to reciprocate with respect to it. The machine also has a motor-driven main shaft rotatably mounted on the frame. Also included is a drive means coupled to and driven by the main shaft to rotate the frame. The machine also has a lapping arrangement mounted on the frame. The lapping arrangement includes thread guides mounted to circulate across the breadth of the needle bed in a direction opposite to the direction of rotation of the frame. The frame and the thread guides have the same period of cycling. The machine also includes a spool storage device having a plurality of spools of thread located upon a fixed creel.
In a preferred embodiment, the thread supply is on spools in a fixed creel and is fed out through a fixed thread guide arrangement lying above the lapping arrangement. Preferably, the machine frame rotates around a vertical axis opposite to the circulating direction of the thread guides but with the same rotation time.
With the foregoing apparatus, unless steps are taken, threads from a creel would become tangled because of the circulation of the thread guides. In order to prevent this, the frame of the warp knitting machine must be turning in the opposite direction. The turning herein may be so slow that service personnel for the machine are perfectly capable of manually watching for errors.
The frame can be continually turnable. This gives rise to a rather simple construction. In particular, it is possible to provide a simple drive means. For example, the frame can be mounted on a turntable which is drivable by means of a reduction gear from the main shaft of the machine. As disclosed hereinafter, more complex rotation schemes are contemplated as well.
It is further advantageous if the number of spools in the creel is chosen to be so large with respect to the working speed of the machine, that the circulating speed of the frame is less than one revolution per minute, suitably less than half a revolution pwer minute. It is therefore advantageous to work with a larger number of warp threads and therefore a larger creel.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be illustrated by reference to the following drawings, wherein:
FIG. 1 is a side elevational view of the machine of the present invention showing the positioning of the appropriate creel.
FIG. 2 is a front elevational view of the machine of FIG. 1.
FIG. 3 is an upward plan view of the underside of the laying arrangement of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred machine of the present invention comprises a frame 1 having two side portions 2 and 3 which are mounted on a turntable 4. This turntable 4 runs on several peripherally mounted rollers 5 rolling on base plate 6. Base plate 6 has affixed to it central fixed gear wheel 7. Bevel gear 8, supported on frame 1, engages gear wheel 7 and by turning turns frame 1. Bevel gear 8 is driven by main shaft 9 through tooth belt 11, reduction gear 10 and gear box 12. In FIG. 1 the gear box 12 comprises a simple tooth drive. The main shaft 9 is driven by a motor 14 through belt drive 15. The normal turning direction of the frame 1 is indicated by arrow 16.
In FIG. 2 gear box 12A is provided as a stepping gear which can be controlled by program arrangement 13. For example, box 12a can be an electricaly controllable transmission. Arrangement 13 can control such a transmission with a cam driven potentiometer or switch contacts (neither shown) connected to the transmission 12a either directly or through a programmable computer (not shown). Arrangement 13 can operate to control turning speed, turning direction and even stopping times in accordance with a predetermined program.
The frame 1 supports a working area 17 to which warp threads 18 are led from a warp beam 19 over a guide bar 20. Warp threads 21 run from warp beam 22 over guide bar 23. Guide bars 20 and 23 are arranged to reciprocate through the usual shogging and/or swinging motions. Warp threads 24 are fed over a laying arrangement 25 via its circulating thread guides 26. The working area 17 is provided with a fabric take off arrangement 27 comprising three take off rollers and a fabric winding roller 28.
The warp threads 24 are pulled off individual spools 29 on a fixed creel 30 and run over two stationary thread guide arrangements 31 and 32 of the lapping arrangement 25. The use of stationary creel 30 makes it possible for the threads 24 to be led from single spools 29. Such single spools 29 can carry substantially larger amounts of threads than a single movable partial warp beam. One can use supersized spools carrying higher weights of thread, for example, 15 kilograms. It is therefore possible to use much thicker threads which are, for example, useful for reinforcement purposes and which can be held in longer lengths on the spools 29. It is also possible to utilize thread materials such as glass or carbon fibers which cannot be warped on warp beams. Indeed, it is possible to construct a creel 30 which is much larger than the rest of the machine. Even the weight of the creel 30 plus the weight of the full spools can be greater than the weight of the machine itself. Because of the separate stationary creel 30, vibrations during thread take-off are, to all intents and purposes non-existent.
The thread guide arrangement comprises a eyelet plate 32 and 31 each of which have one guide opening or eyelet 33 for each weft thread. In the illustrated example of FIG. 3, the eyelet plate 32 is annular and the eyelets 33 are placed circularly around its circumference.
It is advantageous if the turning axis of the frame 1 runs through the center of the eyelet plate 32. This gives great assurance that individual threads 24 do not touch each other. In particular, the thread guide arrangement 32 may be formed by a eyelet plate 32 with equally spaced eyelets 33. It is advantageous if these eyelets 33 are set around a circle with the eyelet plate 32 shaped in the form of a ring since tangling is then very unlikely even though the emerging threads may leave at time-varying angles. Such an arrangement provides an easy way of preventing mutual interference between the strings 24.
The frame 1 comprises a turning axle 34 which by cooperating with guiding wheels 5 through a central trunion, nipple or other means may be definitely determined. The central axis 34 runs through the guiding arrangement 32.
The lapping arrangement 25 is similarly driven from main shaft 9 over a toothed belt 35 in such a manner that the threads 24 move in the direction shown by arrow 36 (if lapping arrangement 25 is taken as a frame of reference). In FIG. 3 where the lapping arrangement 25 is viewed from below, the circulation direction 36 of the lapping arrangement 25 and the turning direction 16 of the frame 1 are similarly indicated.
In FIG. 2 an intermediate drive 37, for example, a stepping drive, is provided which is controlled by a program arrangement 13 by the means of which the lapping pattern may be provided with changes in the circulation movement. For example stopping, higher speed, reverse direction may be imposed on lapping arrangement 25. The circulatory movement of the lapping arrangement 25 and the adjustments to the average speed of frame 1, which are controlled by program arrangement 13, are thereby advantageously adjusted to each other.
There remains the possibility that while the lapping arrangement 25 is subject to a predetermined program control, the frame 1 is continuously driven in such a manner that the circulation time of the frame 1 is equal to the circulation time of the lapping arrangement 25. Under such circomstances, the lapping arrangement 25 can be set up in the known manner, that is to say, be provided with a circulating band with holes or with individual step-wise displaceable carrier elements. It is preferred, however, to utilize an arrangement as is set forth in our co-pending and co-filed application Ser. No. 894,563 filed Aug. 8, 1986 entitled "CIRCULATING THREAD GUIDES."
Synchronization is assured because of the mutual coupling of the lapping arrangement 25 and the turning drive for frame 1 with the main shaft 9 which also drives the knitting arrangement. It is possible to exactly determine the circulation of the thread 24, the turning of the frame 1 and the production speed as well as also the progress of creep. It is also possible to provide a programming arrangement which gives the frame 1 different turning speeds, non-motion and/or different circulation times. This can be advantageous, for example, if the laying arrangement 25 does not run continuously in the circuit, but has a pre-programmed timing and thus the fed thread would collide with each other if the frame turned continually under these circumstances. In particular, the turning drive of the frame 1 should correspond to the appropriate speed, stopping motion and reverse motion of the circulating drive of the thread guides 26.
In each case the warp threads 24 give rise to diagonal patterns on the fabric. In the experimental example a 60 inch (1524 mm) wide machine equipped with seven needles per inch was used. This gives rise to 360 threads on the forward level and 360 on the rearward level. To this are added 2 times 6 threads on the edge in the turning position, thus there are utilized 732 threads per revolution. The machine ran at a working speed of 300 working rows per minute. This corresponds to 0.406 machine circuits per minute at such a speed it is clearly possible for the operator to manually correct and observe any errors.
Frame 1 can also be equipped with a weft thread insert magazine and further thread provision arrangements as is usual. Using this machine it is possible to provide fabric with particularly strong reinforcing threads in all directions which provides high fabric stability as is described in DEOS No. 3304345.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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There is provided a warp knitting machine for diagonally laying warp threads with thread guides that circulate around a continuous pathway. The warp threads are taken from spools located on a fixed creel and are led through a fixed thread feed arrangement located above the circulating path. The frame is rotatable about a perpendicular turning axis in a direction opposite to the direction of rotation of the thread guides. These rotations have the same circuit times. In this way it is possible to provide long time intervals between the stopping times necessary for the replacement of the spools. It also allows the use of many different types of thread material.
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BACKGROUND OF THE INVENTION
The invention is directed to a process for the production of 1-amino-2-mercapto-2-methylpropyl phosphonic acid or 1-amino-2-mercapto-2-methylpropyl alkyl phosphinic acids. These compounds are pharmaceutically active materials, especially suitable for the treatment of inflammations, degenerative diseases of the joints such as rheumatoid arthritis and Wilson's illness.
It is known to produce 1-amino-2-mercapto propyl phosphonic and phosphinic acids by reacting thiazolines-(3), in a given case as the hydrochloride, at elevated temperature in the molten condition or in the presence of a solvent with phosphonic acid (phosphorous acid) or a phosphinic acid and subsequently splitting the thiazolidine ring (EPO published application No. 33919, the entire disclosure of which is hereby incorporated by reference and relied upon). The disadvantage of the process especially is that the yields are only about 30%.
SUMMARY OF THE INVENTION
There has now been found a process for the production of 1-amino-2-mercapto-2-methylpropyl phosphonic acid or 1-amino-2-mercapto-2-methylpropyl alkyl phosphinic acids of the formula: ##STR2## in which Y is a hydroxy or the group R 1 where R 1 is an alkyl group, e.g. of 1 to 12 carbon atoms, from thiazolines-(3) and phosphorus compounds which is characterized by reacting a thiazoline-(3) of the formula: ##STR3## in which R 3 and R 4 are hydrogen or the same or different alkyl groups or are joined together to form with the carbon atom of the ring a closed alkylene ring with an ester of the formula: ##STR4## where R 2 is an alkoxy group and Z is R 1 or R 2 and where R 1 is an alkyl group as defined above and the ester formed of the formula: ##STR5## split hydrolytically. This process results in substantially more favorable yields than the known process.
According to the process of the invention there are produced compounds of formula I in which R 1 is preferably a branched or unbranched alkyl group of 1 to 12 carbon atoms, especially having 1 to 4 carbon atoms. Compounds which are accessible according to the invention, for example are:
1-amino-2-mercapto-2-methylpropyl phosphonic acid,
1-amino-2-mercapto-2-methylpropyl methylphosphinic acid,
1-amino-2-mercapto-2-methylpropyl ethylphosphinic acid,
1-amino-2-mercapto-2-methylpropyl isopropylphosphinic acid, and
1-amino-2-mercapto-2-methylpropyl butylphosphinic acid.
There are preferably used for the reaction of the invention thiazoline-(3) compounds of the formula (II) in which R 3 and R 4 are hydrogen or the same or different alkyl groups having 1 to 3 carbon atoms. The alkyl groups can be joined together with the adjacent ring carbon atom to form a closed alkylene ring having 5 to 8 carbon atoms. There can be employed for example thiazoline-(3) compounds such as: 5,5-dimethyl-thiazoline-(3), 2,5,5-trimethyl-thiazoline-(3), 2-ethyl-5,5-dimethyl-thiazoline-(3), 2-propyl-5,5-dimethyl-thiazoline-(3), 2,2-dipropyl-5,5-dimethyl-thiazoline-(3), 2,2-tetramethylene-5,5-dimethyl-thiazoline-(3), 2,2-pentamethylene-5,5-dimethyl-thiazoline-(3) and especially 2-isopropyl-5,5-dimethyl-thiazoline-(3), 2,2-5,5-tetramethyl-thiazoline-(3) and 2,2-diethyl-5,5-dimethyl-thiazoline-(3).
According to the invention the thiazoline-(3) is reacted with an ester of formula (III). In this compound R 2 is preferably an alkoxy group which contains a branched or unbranched alkyl group having 1 to 12, especially 1 to 4, carbon atoms. Z stands for R 1 or R 2 with the above defined meanings. For example there can be employed as esters of formula III dimethyl phosphite, diethyl phosphite, diisopropyl phosphite, dibutyl phosphite, dihexyl phosphite, bis decyl phosphite, bis dodecyl phosphite, methyl ester of methylphosphinic acid, ethyl ester of methyl phosphinic acid, isobutyl ester of methylphosphinic acid, hexyl ester of methylphosphinic acid, dodecyl ester of methylphosphinic acid, isobutyl ester of ethylphosphinic acid, methyl ester of ethylphosphinic acid, methyl ester of propylphosphinic acid, ethyl ester of butylphosphinic acid.
In the reaction according to the invention of the thiazolidine-(3) of formula II with an ester of formula III there are formed esters of formula IV. These esters include for example 5,5-dimethyl-4-thiazolidinyl-phosphonic acid dimethyl ester, 5,5-dimethyl-4-thiazolidinyl-phosphonic acid diethyl ester, 2,5,5-trimethyl-4-thiazolidinyl-phosphonic acid dimethyl ester, 2-ethyl-5,5-dimethyl-4-thiazolidinyl-phosphonic acid diisopropylester, 2-isopropyl-5,5-dimethyl-4-thiazolidinyl-phosphonic acid dimethyl ester, 2-isopropyl-5,5-dimethyl-4-thiazolidinyl-phosphonic acid diethyl ester, 2-isopropyl-5,5-dimethyl-4-thiazolidinyl-phosphonic acid diisopropyl ester, 2,2,5,5-tetramethyl-4-thiazolidinylphosphonic acid diethyl ester, 2,2-diethyl-5,5-dimethyl-4-thiazolidinyl-phosphonic acid diethyl ester, 2,2-tetramethylene-5,5-dimethyl-4-thiazolidinyl-phosphonic acid diethyl ester, 2,2-pentamethylene-5,5-dimethyl-4-thiazolidinyl-phosphonic acid diisopropyl ester, 5,5-dimethyl-4-thiazolidinyl-methylphosphinic acid isobutyl ester, 2-ethyl-5,5-dimethyl-4-thiazolidinyl-ethyl-phosphinic acid isobutyl ester, 2-isopropyl-5,5-dimethyl-4-thiazolidinyl-methylphosphinic acid methyl ester, 2-isopropyl-5,5-dimethyl-4-thiazolidinyl-methylphosphinic acid isobutyl ester, 2-isopropyl-5,5-dimethyl-4-thiazolidinyl-ethylphosphonic acid isobutyl ester 2,2,5,5-tetramethyl-4-thiazolidinyl-methylphosphinic acid ethyl ester, 2,2-diethyl-5,5-dimethyl-4-thiazolidinyl-methylphosphinic acid methyl ester, 2,2-diethyl-5,5-dimethyl-4-thiazolidinyl-methylphosphinic acid isobutyl ester, 2,2-tetramethylene-5,5-dimethyl-4-thiazolidinyl-ethylphosphinic acid isobutyl ester, and 2,2-pentamethylene-5,5-dimethyl-4-thiazolidinyl-methylphosphinic acid isobutyl ester.
The esters of formula IV are new. They are also a part of the present invention.
To carry out the process of the invention the thiazoline (II) and the ester (III) are employed in substantially any molar ratio. Preferably there are used per mole of ester (III) 0.7 to 1.5 moles, especially about 1.0 mole, of the thiazoline (II). The reaction of the thiazoline (II) with the ester (III) is carried out suitably in liquid medium, preferably in the presence of an inert solvent. As solvent there can be used for example aliphatic or aromatic hydrocarbons which in a given case can be chlorinated. Illustrative are petroleum ether, decane, trichloroethylene, chlorobenzene, benzene, toluene and xylene.
The temperature at which the reaction is carried out in a given case depends on the type of compounds being reacted and, in case a solvent is used, on the type of solvent. Generally it is suitable to choose temperatures near the boiling point of the reaction mixture. In case a solvent is not used, however, the temperature should be at least that at which the reaction mixture is present as a melt. In most cases temperatures of about 50° to 250° C., especially 100° to 190° C. are advantageous.
The pressure can be selected substantially at choice, however, it is generally suitable to carry out the reaction at pressures which do not deviate substantially from normal pressure. In many cases because of the volatility of the materials at the temperatures used, it is necessary to operate at a corresponding elevated pressure.
For the hydrolytic splitting of the ester IV formed in the reaction, this is treated in aqueous medium, namely with at least stoichiometric amounts of water. In the case of the phosphonic acid esters there are required at least 3 moles of water and in the case of the phosphinic acid esters at least 2 moles of water per mole of the ester.
The treatment is carried out with water or with aqueous acids. Suitable are inorganic as well as organic acids insofar as they are not disturbing and especially are not decomposing, for example sulfuric acid or acetic acid. Preferably there is used hydrochloric acid. Generally elevated temperatures are required. Advantageous are temperatures between about 50° C., especially between 80° C., and the boiling point of the medium. The pressure hereby can also be chosen substantially at random. An especially preferred mode of operation is to drive off steam or to lead steam through the reaction mixture.
Unless otherwise indicated all parts and percentages are by weight.
The process can comprise, consist essentially of, or consist of the stated steps with the recited materials.
DETAILED DESCRIPTION
EXAMPLES
A. Production of the Thiazodinyl Phosphonic Acid Esters and the Thiazolidinyl Alkylphosphinic Acid Esters
EXAMPLE 1
A mixture of 314 grams (2 moles) of 2-isopropyl-5,5-dimethyl-thiazoline-(3), 276 grams (2 moles) of diethyl phosphite and 300 ml of petroleum ether (B.P. 120° to 150° C.) were held for 15 hours with the exclusion of moisture at 120° C. and then cooled to 20° C. In the cooling there separated out 2-isopropyl-5,5-dimethyl-4-thiazolidinyl phosphonic acid diethyl ester in the form of colorless crystals. These were filtered off, washed with 1000 ml of petroleum ether (B.P. 30° to 70° C.) and dried at 40° C. and 25 mbar. The yield was 509 grams, corresponding to 86%. The melting point of the material was 68° to 69° C. The elemental analysis showed: C=48.84% (48.79%); H=9.14% (8.87%); N=4.75% (4.74%); P=10.44% (10.49%); S= 10.31% (10.85%) - (in parantheses the calculated values for C 12 H 26 NO 3 PS).
EXAMPLE 2
The procedure was as in Example 1 but there were employed 342 grams (2 moles) of 2,2-diethyl-5,5-dimethyl-thiazoline-(3) and the 2,2-diethyl-5,5-dimethyl-4-thiazolidinyl phosphonic acid diethyl ester obtained was dried at 25° C. and 25 mbar. The yield was 489 grams, corresponding to 79%. The melting point of the material was 40° C. The elemental analysis showed: (C=50.29% (50.46%); H=9.31% (9.21%); N=4.51% (4.54%); P=10.20% (10.36%); S=9.98% (10.01%) - (in parantheses the calculated values for C 13 H 28 NO 3 PS).
The spectral analysis showed:
1 H-NMR(CDCl 3 ): δ=4.2 (mc. 4H) 0=CH 2 -CH 3 ; 3.20 (d, J=19 Hz, 1H) P-CH; 3.09 (S, 1H) NH; 2.1 - 0.7 ppm (m, 22H).
EXAMPLE 3
A mixture of 339 grams (2 moles) of 2,2-tetramethylene-5,5- dimethyl thiazoline-(3), 276 grams (2 moles) of diethyl phosphite and 300 ml of petroleum ether (B.P. 100° to 200° C.) were held for 15 hours at 105° C. Petroleum ether was evaporated from the reaction mixture at 30 mbar until crystallization occurred. The residue was cooled to 0° C. and filtered. The filter residue was washed with 500 ml of cold petroleum ether (B.P. 30° to 70° C.) and dried at 30° C. and 25 mbars. There were obtained 516 grams of 2,2-tetramethylene-5,5-dimethyl-4-thiazolidinyl-phosphonic acid diethyl ester corresponding to a yield of 91%. The melting point of the material was 61° to 63° C. The elemental analysis showed: C=50.77% (50.79%); H=8.60% (8.52%); N - 4.50% (4.56%); P=10.23% (10.08%); S=10.28% (10.43%) - (in parantheses the calculated values for C 13 H 26 NO 3 PS).
The spectral analysis showed:
1 H-NMR(CDCl 3 ): δ=4.20 (mc. 4H) O-CH 2 -CH 3 ; 3.13 (d, J=19 Hz, 1H) P-CH; 2.75 (s, 1H) NH ; 2.3 - 1.2 ppm (m, 20H).
EXAMPLE 4
A mixture of 92 grams (0.5 mole) of 2,2-pentamethylene-5,5-dimethyl thiazoline-(3), 69 grams (0.5 mole) of diethyl phosphite and 70 ml of petroleum (B.P. 140° to 200° C.) were held for 15 hours at 125° C. and then cooled to 0° C. In the cooling there separated out crystalline 2,2-pentamethylene-5,5-dimethyl-4-thiazolidinyl phosphonic acid diethyl ester. This material was filtered off, washed with 50 ml of n-pentane and dried for 24 hours at 50° C. and 30 mbar. The yield was 146 grams, corresponding to 91%. The melting point was 77° to 79° C. The elemental analysis showed: C=52.26% (52.32%); (*)
1 H-NMR(CDCl 3 ): δ=4.20 (mc. 4H) O-CH 2 -CH 3 ; 3.25 (d, J=19 Hz, 1H) P-CH; 2.0 - 1.0 ppm (m, 22H)
EXAMPLE 5
100 grams (0.7 mole) of 2,2,5,5-tetramethylthiazoline-(3) were mixed at 20° C. with 104 grams (0.8 mole) of diethyl phosphite. The mixture was held for 14 hours at 20° C. and 12 hours at 105° C. Then it was distilled. The 2,2,5,5-tetramethyl-4-thiazolidinyl phosphonic acid diethyl ester was obtained as a yellow oil. Its boiling point was 104° to 106° C. at 0.4 mbar. After addition of petroleum ether (B.P. 30° to 70° C.) and cooling there crystallized out of the oil the 2,2,5,5-tetramethyl-4-thiazolidinyl phosphonic acid diethyl ester. The yield was 14.5 grams, corresponding to 75%, based on the thiazoline employed. The elemental analysis of the ester obtained showed: C=46.88% (46.97%); H=8.89% (8.54); N=4.97%
The spectral analysis showed: (4.98%); P=11.11% (11.03%); S=11.40% (11.39%) - in parantheses the calculated values for C 11 H 24 NO 3 PS).
EXAMPLE 6
A mixture of 12.6 grams (0.08 mole) of 2-isopropyl-5,5-dimethyl-thiazoline-(3), 10.9 grams (0.08 mole) of methylphosphinic acid isobutyl ester and 15 ml of petroleum (B.P. 140° to 200° C.) were maintained at 120° C. for 15 hours and then cooled to 0° C. In the cooling there separated out 2-isopropyl-5,5-dimethyl-4-thiazolidinyl methylphosphinic acid isobutyl ester. The material was filtered off, washed with 10 ml of cold petroleum ether (B.P. 30° to 70° C.) and dried for 24 hours at 40° C. and 20 mbar. The yield was 18.5 grams, corresponding to 79%. The melting point of the material was 91° to 93° C. The elemental analysis showed: C=53.11% (53.22%); H=9.56% (9.62%); N=4.69% (4.77%); P=10.89% (10.92%); S=10.57% (10.56%) - (in parantheses the calculated value for C 13 H 28 NO 2 PS). The spectral analysis showed:
1 H-NMR(CDCl 3 ): δ=4.40 (d, J=7 Hz, 1H)-CH; 3.73 (mc, 2H) CH-CH 2 ; 2.80 (d, J=10 Hz, 1H) P-CH; 2.50 (s, sH) NH; 2.24 - 1.40 (m, 11H); 1.15 - 0.07 ppm (m, 6H).
EXAMPLE 7
The procedure was as in Example 6 but there were employed 14.7 grams (0.08 mole) of 2,2-pentamethylene-5,5-dimethyl thiazoline-(3). There were obtained 19.6 grams of 2,2-pentamethylene-5,5-dimethyl-4-thiazolidinyl methylphosphinic acid isobutyl ester, corresponding to a yield of 77%. The melting point of the material was 94° to 96° C. The elemental analysis showed: C=56.41% (56.40%); H=9.66% (9.46%); N=4.36% (4.38%); P=10.06% (10.04%); S=9.76% (9.70%) - (in parantheses the calculated values for C 15 H 30 NO 2 PS). The spectral analysis showed:
1 H-NMR(CDCl 3 ): δ=3.78 (mc, 2H) O-CH 2 -CH 3 ; 3.12 (d, J=10 Hz, 1H) P-CH; 2.78 (s, 1H) NH; 2.15 - 1.2 (m, 20H); 0.93 ppm (d, J=7 Hz)(CH 3 ) 2 CH;
B. Hydrolytic Splitting of the Thiazolidinyl-Phosphonic Acid Ester and Thiazolidinyl Alkylphosphinic Acid Ester
EXAMPLE 1
2.95 grams (0.01 mole) of the 2-isopropyl-5,5-dimethyl-4-thiazolidinyl phosphonic acid diethyl ester obtained according to Example A1 was treated with 20 ml of semi-concentrated aqueous hydrochloric acid. The mixture was held under reflux at the boiling temperature for 5 hours, then subjected to a steam distillation and subsequently brought to dryness. The residue was dissolved in 8 ml of water, the solution clarified with activated carbon, mixed with 40 ml of ethanol and regulated to pH of 5 through addition of triethylamine. Thereby there separated out the 1-amino-2-mercapto-2-methylpropylphosphonic acid in the form of colorless crystals. It was filtered off, washed successively with 10 ml of ethanol and 10 ml of dimethyl ether and subsequently dried at 80° C. and 25 mbar. The yield was 1.70 grams, corresponding to 92%. The melting point of the material was 242° to 246° C.
EXAMPLE 2
30.9 grams (0.1 mole) of the 2,2-diethyl-5,5-dimethyl-4-thiazolidinyl phosphonic acid diethyl ester obtained according to Example A2 were treated successively with 40 ml of 12N aqueous hydrochloric acid and 210 ml of water. The mixture was subjected to a steam distillation for 23 hours.
Thereby there were distilled 4000 ml. The remaining reaction mixture was brought to dryness in a rotary evaporator. The residue was dissolved with heating in 40 ml of 6N aqueous hydrochloric acid, the solution treated with 400 ml of ethanol and adjusted to pH 5 by addition of trimethylamine. Thereby there separated out the 1-amino-2-mercapto-2-methylpropyl phosphonic acid in the form of colorless crystals. It was filtered under suction, washed successively with ethanol and diethyl ether and subsequently suction dried. The yield was 16.1 grams, corresponding to 87%. The melting point of the material was 243° to 246° C.
EXAMPLE 3
4.2 grams of the 2,2,5,5-tetramethyl-4-thiazolidinyl phosphonic acid diethyl ester obtained according to Example A5 was held in 20 ml of semi-concentrated aqueous hydrochloric acid for 5 hours under reflux at the boiling point. The mixture was evaporated to dryness, the residue dissolved in 10 ml of water with heating and the solution clarified with activated carbon. In the cooling there separated out crystalline 1-amino-2-mercapto-2-methylpropyl phosphonic acid. The material was filtered off and washed with 3 ml of water. The filtrate was adjusted to pH 3 by the addition of triethylamine and then treated with an equal volume of ethanol. Thereby there separated out a further amount of 1-amino-2-mercapto-2-methylpropyl phosphonic acid. The yield altogether was 2.5 grams, corresponding to 89%. The melting point of the material was 249° to 251° C.
EXAMPLE 4
There were used the reaction mixture directly as produced according to Example A5 as it was present before the distillation and it was treated with 790 ml of semi-concentrated aqueous hydrochloric acid. The mixture was held under reflux at the boiling temperature for 5 hours, then subjected to a steam distillation for 2 hours and finally brought to dryness. The residue was dissolved in 345 ml of water, the solution clarified with acticated carbon, mixed with 345 ml of ethanol and adjusted to pH 3 by addition of triethylamine. The 1-amino-2-mercapto-2-methylpropyl phosphonic acid separated thereby, was filtered off, washed with ethanol and diethyl ether and finally dried at 80° C. and 25 mbar. The yield was 85.3 grams, corresponding to 89%. The melting point of the material was 249° to 251° C.
EXAMPLE 5
2.93 grams (0.01 mole) of the 2-isopropyl-5,5-dimethyl-4-thiazolidinyl methyl phosphinic acid isobutyl ester obtained according to Example A6 was suspended in 50 ml of semi-concentrated aqueous hydrochloric acid. The mixture was held for 2.5 hours under reflux at the boiling temperature, then subjected for 4 hours to a steam distillation and finally brought to dryness in a rotary evaporator. The residue was dissolved in 30 ml of water. The solution was mixed with 100 ml of ethanol and adjusted to pH 5.1 by addition of triethylamine. Thereby there separated out 1-amino-2-mercapto-2-methylpropyl methylphosphinic acid in the form of colorless crystals. The material was filtered off, washed with a mixture of propanol-2 and methyl tert. butyl ether and finally dried. The yield was 1.72 grams corresponding to 94%. The melting point was 221° C.
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There are prepared 1-amino-2-mercapto-2-methylpropyl phosphonic acid or 1-amino-2-mercapto-2-methylpropyl alkylphosphinic acids of the formula ##STR1## in which Y is hydroxy or an alkyl group by reacting thiazoline-(3) with a phosphonic acid dialkyl ester or an alkylphosphinic acid alkyl ester and then hydrolytically splitting the thiazolidinyl phosphonic acid dialkyl ester or thiazolidinyl alkylphosphinic acid alkyl ester. The thiazolidinyl compounds are new compounds. The 1-amino-2-mercapto-2-methylpropyl phosphonic acid and the 1-amino-2-mercapto-2-methylpropyl alkylphosphinic acids are needed for pharmaceutical purposes.
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BACKGROUND OF THE INVENTION
The present invention relates generally to centrifugal blowers and more particularly to a means for reducing the noise of a centrifugal blower.
Centrifugal blowers and centrifugal fans are well known devices for blowing air and, in some instances, other fluids. A centrifugal blower has a fan wheel and a casing, or housing, with a cutoff as well as an air inlet and an air outlet. The fan wheel is of generally cylindrical configuration having blades facing forward or backward relative to the direction of rotation thereof about the axis of the cylinder. The casing typically is spiral in shape to collect the air delivered from the fan wheel and to conduct the same in a spiral flow pattern to the outlet.
A typical centrifugal blower includes a cylindrical fan wheel having a radial center along its axis and a spiral shaped blower housing with a blower outlet at one end thereof. The air inlet to the blower is in a side wall to permit air flow into the center of the fan wheel.
The spiral blower housing has an approximate center of curvature, otherwise known as a radial center, which is the theoretical center of the spiral, but approximately falling in the vicinity of the radial center of the fan wheel. The blower housing has two wall portions which lead generally to the blower outlet. One of those wall portions is that part of the spiral shape of the blower housing that is relatively far or remote from the spiral center, and the other wall portion may be considered the involute wall portion. The latter is generally curved inwardly along the track of the spiral toward the center thereof. Typically, the fan wheel is positioned so that it is relatively near the involute wall surface but relatively far from the remote wall portion. With the fan wheel so positioned, there is a generally annular spirally expanding flow path along which air may be blown by the rotating fan toward the blower outlet for discharge from the fan wheel in a generally linear flow direction or flow path. Linear is used herein to indicate a non-spirally confined flow path, and may be a divergent one as the air blown through the blower outlet may diverge or expand upon so leaving.
In the past, furnace parts were made of galvanized metal and the housings for furnace fans and other centrifugal blowers were also made from galvanized metal. In more recent technology, the housing for centrifugal fans is molded of a plastic material. This permits the integral formation of the housing with the outlet.
A "cutoff" occurs at the end of the involute wall portion relatively proximate to the blower outlet. A cutoff is formed at the transition point where the spiral air flow occurring in the housing is transformed to the relatively straight line discharge air flow through the blower outlet. During such transition, the typical cutoff tends to cut off or to impede air flow through the clearance area between the cutoff and the fan wheel, which in the instance of the present invention, rotates in a clock-wise direction.
Generally, the blower outlet is a cylindrical tube connected to the housing into which the air is blown from the housing through an opening into the cylindrical outlet. Integrally molded housings with outlets permit formation of openings which can optimize the path of the spiral air flow during its transition to the straight line air flow. The cutoff region contributes significantly to audible noise, notably, an audible tone or whistle-like sound. In spite of efficiently designed openings from the housing into the outlet, the noise level at the cutoff continues to exist.
Certain attempts have been made to deal with the audible noise at the cutoff. For instance, in U.S. Pat. No. 5,040,943, the passageway from the housing to the outlet is designed such that the opening is absent any vertical edge in juxtaposition to the fan, the edge having a geometry of uniformly changing dimensions. Whereas, such a design may have diminished some of the audible noise, there is still existing a considerable audible noise at the point where the blade of the fan passes the cutoff.
The present invention provides an improved configuration of the opening for the passage of air from the housing into the outlet in a centrifugal blower.
SUMMARY OF THE INVENTION
The present invention provides an integrated centrifugal blower housing, and an air flow outlet, whereby the intersection of the housing and the outlet provides an opening, one edge of which contains at least one fin extending downwardly into the opening and positioned to generate at least one vortex in the flow of the air from the housing through the opening into the outlet. The opening from the housing into the outlet is defined, commencing at the base opposite the cutoff, by a vertical line extending from the base of the housing, upwardly terminating in a straight horizontal line, which line ends in a parabolic curve downwardly terminating at the base at the cutoff. The parabolic curve is interrupted by the fin. The fin is substantially triangular in shape and extends downwardly from the parabolic curve with a vertical edge facing the cutoff. The vertical height of the fin may vary depending upon the vortex strength required, but is generally from about 10% to about 60% of the height of the opening where the fin is situated. The fin is preferably situated on the parabolic curve at a point located from about 40% to about 70% of the length of the curve from the base at the cutoff end. While a specific location of the fin is shown and described in the drawings, those skilled in the art will understand that the location and number of fins may vary in other embodiments of the present invention.
The fin creates a marked change in the path of the air flow at the cutoff. The fin creates a vortex in the air flow, the vortex being located substantially behind the fin on the side of the housing, and causes the air flow at the cutoff to be markedly changed substantially eliminating the audible noise at the cutoff.
The most discernible noise by the human ear is caused by that of the blades of the radial fan passing the cutoff. The frequency generated by that noise is well within the discernible range of the human ear. Consequently, the most irritating noise caused by the centrifugal blower is the blade passing noise at the cutoff. The present invention provides a means of altering the air flow in such a manner as to substantially reduce the noise caused by the blade passing at the cutoff.
BRIEF DESCRIPTION OF THE DRAWING
In the drawings FIG. 1 is a perspective view of the housing of a centrifugal blower of one embodiment of the present invention;
FIG. 2 is a top plan view of the centrifugal blower housing of FIG. 1;
FIG. 3 is a partial sectional view along line 3--3 of the embodiment of FIG. 2 of the invention;
FIG. 4 is a graph depicting one embodiment of the present invention; and
FIG. 5 is a graph depicting another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With respect to FIG. 1, FIG. 1 depicts a portion of a centrifugal blower housing 10. The housing 10 is generally spiral in shape to collect the air delivered from the fan wheel, and to conduct the same in a spiral flow pattern to an outlet 25. The housing 10 has a base 18 and vertical walls 12 and 14. The wall 12 extends away from the fan wheel which is seated on an axis located at a hole 16. The wall 14 is an involute wall and extends inwardly toward the fan wheel (not shown). The air is moved in a clockwise direction and is delivered to the fan wheel through a side opening not shown in FIG. 1. The fan wheel will bring the air from the involute wall in a clockwise direction past the wall 12 and into an opening 22. The opening 22 is an opening in the housing 10 and opens into an outlet 25. The opening 22 which transports the air from the housing 10 to an outlet 25, has a shape which is designed to lower the noise of the fan in conjunction with air flow. Specifically, the opening 22 commencing at the base 18 at the wall 12, extends vertically and terminates in a horizontal line which terminates downwardly in a parabolic curve. The parabolic curve terminates at the base 18 on the wall 14 and creates a cutoff 24. The cutoff causes noise as the blades of the fan wheel pass the cutoff region. In order to redirect the flow of air to lessen the noise at the cutoff, a fin 26 is provided and situated approximately mid-way on the parabolic curve extending downwardly. The fin 26 has a vertical edge which allows a vortex to be created behind the fin 26 creating a negative pressure such that the air flow pattern is changed at the cutoff 24, and hence the noise is substantially reduced at the cutoff 24. The housing 10 is a section of the overall housing for a centrifugal blower. The housing 10 has a flange 20 with spaced holes to allow bolting of the portion of housing 10 to another mated portion to complete the centrifugal blower housing.
With respect to FIG. 2, a top plan view is depicted of a housing portion 10. The housing portion 10 has a base 18 and walls not visible in the top plan view which terminate in a flange 20, the flange having holes for mating the portion of housing to another part of the centrifugal blower housing. A hole 16 locates the axis of a fan wheel, not shown, which moves air within the housing. The opening 22 into the outlet 25 has a cutoff 24. In FIG. 3, the opening 22 of FIG. 2 is clearly depicted as viewed along line 3--3. In FIG. 3, the configuration of the opening 22 is defined by the base 18, a wall 12, and a portion of a wall 14. The wall 14 defines the opening with a straight line 44 coming from the wall 12, extending horizontally, ending in a parabolic curve 42, extending downwardly, and ending at the base 18. The parabolic curve 42 intersection with the base at 18 creates a cutoff 24. Approximately, midway on the parabolic curve is located a fin 26.
FIG. 4 is a graph depicting the prior art in dotted line and the present invention in the solid line. The graph indicates from the range of 0 to 3200 Hz, the noise level in decibels, which each blower provides. The peaks of noise from the prior art product at point A and point B are particularly disturbing to the human ear. It should be noted that the present product substantially eliminates these peaks of noise. The noise at the peak identified as B, is the blade-passing noise at the cutoff. The prior art centrifugal fan is one produced by Emerson Electric, St. Louis, Mo.
With respect to FIG. 5, the graph is very similar to FIG. 4; however, the dotted line represents the prior art which is a commercial unit manufactured by Ametec-Lamb Electric of Kent, Ohio, appearing to be in accordance with U.S. Pat. No. 5,040,943. Here again, it should be noted, that the blade passing noise is depicted by the point marked E on the graph, but it should be observed that the present invention denoted by the solid line substantially reduces the noise, for instance at points C and D, in much of the decibel range, which is particularly disturbing to the human ear.
For instance, as shown in Table 1 below, the blade passing amplitude in the prior art is shown in Sample Nos. 1 through 9. Sample Nos. 8 and 9 are subsequently modified according to the invention and the results are found in samples A through G. In each instance except Sample C, the fin was placed such that the tip of the fin was located at approximately 55% of the distance on the parabolic curve from the base of the parabolic curve. In the case of Sample C, a tip of the fin was located at about 65% of the distance from the base of the parabolic curve.
TABLE I______________________________________ Overall Noise Blade-Passing Fan WheelSample No. dB (A) Amplitude dB RPM______________________________________1 69 60 32892 66 54 32673 66 51 33174 66 55 33175 69 54 32806 66 55 33157 68 61 32908 67 58 33019 68 61 3301A 65 47 3310B 65 51 3317C 66 53 3320D 66 47 3327E 66 47 3318F 67 49 3323G 66 48 3317______________________________________
Although the Samples A through G show only a slight improvement in overall noise over the prior art Sample Nos. 1-9, the difference in blade passing amplitude is significant. Each of the modified samples had a fin described as the preferred embodiment of the present invention. The noise reduction over that of Sample Nos. 8 and 9 by A through G including Sample C was about 18%. This is a considerable reduction in noise. The average noise reduction over the average blade passing amplitude of the prior art is 14%. This still is a significant reduction in noise.
Most generally a single fin extending downwardly from the top of the opening is sufficient to create the desired vortex. However, if an even stronger vortex is desired, more fins can be added extending upwardly from the base immediately below the first fin. Preferably the extra fin(s) would also have a vertical side facing the cutoff.
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The present invention provides a centrifugal blower wherein the noise at the cutoff has been substantially reduced by providing a vortex in the air flow near the cutoff to redirect the air flow. A fin projects downwardly into the space created by the exhaust outlet to redirect the air flow away from the cutoff and create a vortex to quiet the air flow.
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BACKGROUND OF THE INVENTION
The present invention relates to a zero insertion force (ZIF) socket, and especially to a ZIF socket which ensures stable reliable electrical connection between an IC package and a circuit board without the help of a cam lever.
A conventional ZIF socket are disclosed in U.S. Pat. Nos. 5,489,218, and 5,679,020. Such conventional ZIF socket commonly has a cam attached between a base and a slidable cover for driving the slidable cover to slide along a top surface of the base from an original position to a final position. In the original position, pins of an IC package do not contact with the corresponding terminals fixed in the base. When the cover is driven by the cam to the final position, the pins of the IC package are properly positioned to electrically contact the corresponding terminals of the ZIF socket, and the cover is secured with the base at the final position. The cam is usually fixed to a lateral side of the ZIF socket, thus, the cam occupies a relatively large space and does not promote miniaturization of the ZIF socket.
A conventional ZIF socket without a cam is disclosed in U.S. Pat. No. 5,730,615. The ZIF socket comprises a base and a cover. Two expansion sections laterally extend from the base and the cover, respectively. Each expansion section defines a receiving slot therein whereby the cover is actuated to move in a front-to-end direction by inserting a flat tool into the receiving slots of both the base and the cover, and successively moving the flat tool in the receiving slots rearwardly and forwardly, whereby terminals fixed in the base electrical contact with corresponding pins of an IC package, which are positioned within the cover.
However, the conventional ZIF socket without a cam does not include a retention member to lock a cover of the ZIF socket at a final position the pins of an IC package engage with corresponding contacts of the ZIF socket. Therefore, the slidable covers are apt to move whereby the pins of the IC package may disengage from the contacts of the ZIF sockets when an exterior force is exerted on the ZIF socket.
Another conventional ZIF socket without a cam lever is disclosed in U.S. Pat. No. 4,988,310. The socket includes a base housing and a cover slidably mounted on the housing which drives pins of an IC package to electrically engage with corresponding contact elements disposed in the base housing. The socket further comprises a spring fixed in a slot defined in a lateral side of the base with legs extending into a corresponding slot defined in the cover. When the cover is moved by an external tool, the spring is biased to allow the pins of an IC package to engage with the contact elements of the socket. Since the inserting force exerted on the pins of the IC package by all the contacts is much greater than the biasing force exerted by the spring, the cover can not disengage from the pins without assistance from an external force provided by the socket.
The biasing force exerted by the spring can be balanced by some of the force exerted on the pins of the IC package by the contacts. However, the biasing force reduces a normal force exerted on the pins by the contacts thereby increasing contact impedance between the pins and the corresponding contacts. Thus, poor electrical connection quality will result.
BRIEF SUMMARY OF THE INVENTION
A main object of the present invention is to provide a ZIF socket having a retention member for ensuring proper electrical engagement and disengagement between pins of a mating IC package and contacts of the present invention.
Another object of the present invention is to provide a ZIF socket having a retention member for ensuring proper contact forces between pins of an IC package and contacts of the ZIF socket thereby achieving an excellent electrical connection between the ZIF socket and the IC package.
In order to achieve the object set forth, a ZIF socket in accordance with the present invention comprises a dielectric base retaining a plurality of contacts therein, a slidable cover, and a resilient retention member mounted between the base and the slidable cover. The base forms first and second platforms outwardly projecting from opposite lateral sides thereof for providing the cover a moving space to slide along a top surface of the base. The second platform defines an access cavity in a top face thereof for insertion of a tool being to operate the cover to slide along the top surface of the base, a receiving slot proximate the access cavity, a groove proximate the receiving slot, and a recess communicating with the access cavity, the groove and the receiving slot. The recess cooperates with the receiving slot for receiving the retention member therein. A block extends from an outer lateral edge of the second platform for cooperation with a side wall of the first platform to define the moving space. The cover also defines a cutout corresponding to the access cavity of the base, and a retention section corresponding to the receiving slot of the base for engaging with the resilient retention member.
The resilient retention member comprises a main body disposed in the recess of the base, a retention portion extending through the receiving slot of the base into the retention section of the cover, a pressing portion partially extending into the access cavity, and a positioning portion extending into the groove. The positioning portion forms a barb on a lateral face for securely engaging within a notch defined in an inner side wall of the groove of the base. When an external tool is inserted through the cutout of the cover into the access cavity of the base to press the pressing portion of the retention member, the pressing portion and the main body simultaneously occur elastic deformations and downwardly pivotally move about the barb of the positioning portion. Thus, the retention member is driven to deflect and releases the cover whereby the cover can be driven to slide along the upper surface of the base for allowing pins of a mating IC package to engage with the corresponding contacts mounted in the base. When the tool is removed from the access cavity of the base, the main body and the pressing portion will recover from the elastic deformations while the retention portion of the retention member engages again with the retention section of the cover thereby locking the cover and the base together.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a ZIF socket of the present invention;
FIG. 2 is an assembled view of FIG. 1;
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2;
FIG. 4 is a perspective view of a retention member of the present invention;
FIG. 5 is another perspective view of the retention member of FIG. 4;
FIG. 6 is similar to FIG. 3 of a base taken along line 6--6 of FIG. 1; and
FIG. 7 is a cross-sectional view showing a tool being operated to move the retention member fixed in the ZIF socket.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1, 2 and 6, a zero insertion force (ZIF) socket 1 comprises a dielectric base 2, a slidable cover 3 mounted to a top surface 27 of the base 2, a plurality of contacts 4 received in the base 2, and a resilient retention member 5 fixed in the base 2. The base 2 is rectangular and defines an opening 22 in a middle thereof and a plurality of contact receiving passageways 21 therein for receiving the corresponding contacts 4.
First and second platforms 23, 24 outwardly extend from opposite sides of the base 2, and each platform 23, 24 has a top face (not labeled) flush with a top surface 27 of the base 2. The second platform 24 defines an access cavity 25 in the top face thereof for insertion of an external tool, a groove 261 proximate the access cavity 25, a receiving slot 262 in the top face between the access cavity 25 and the groove 261 for engaging with the retention member 5, and a recess 26 in the top face of the second platform 24 communicating with the access cavity 25 for insertion of the retention member 5, the groove 261 and the receiving slot 262. A block 241 upwardly extends from a lateral edge of the second platform 24. The first platform 23 forms a side wall 231 for cooperating with the block 241 of the first platform 24 to define a moving space (not labeled) in which the cover 3 is movable.
The cover 3 also defines an opening 30 in a middle thereof and a plurality of pin receiving passageways 31 therein for receiving pins of a mating IC package. A pair of abutting flanges 37 extends from opposite sides of the cover 3 for abutting against corresponding sides of the base 2 thereby limiting movement of the cover 3 perpendicular to a direction "A". A pair of tabs 33 extends from an edge of the cover 3 for covering the second platform 24 thereby positioning the cover 3 at a first position. A cutout 34 is defined between the tabs 33 corresponding to the access cavity 25 of the base 2. A retention section 32 is defined in one of the tabs 33 corresponding to the receiving slot 262 of the base 2 for engaging with the retention member 5. The retention section 32 can either be a slot or a recess. If the retention section 32 is a recess, the recess is exposed to a bottom surface of the cover 3. When the tabs 33 are positioned on the first platform 24, a distance "B" is defined between an edge of the cover 3 opposite the tabs 33 and the side wall 231 of the first platform 23 for allowing the cover 3 to smoothly slide along the top surface 27 of the base 2.
Referring also to FIGS. 4 and 5, the retention member 5 is made of dielectric material or metal material or other suitable material having appropriate resiliency. The retention member 5 comprises a main body 50, a positioning portion 51 downwardly extending from a free end of the main body 51 for engaging within the groove 261 of the base 2, a retention portion 52 upwardly extending from a middle of the main body 51 for insertion into the receiving slot 262 of the base and the retention section 32 of the cover 3, and a pressing portion 53 outwardly extending from the other free end of the main body 51 opposite and perpendicular to the positioning portion 51 for being pressed by an external tool 7 to engage or disengage the retention member 5 with the cover 3. The pressing portion 23, the retention portion 52, and the positioning portion 51 are all perpendicular to each other. The main body 50 has a straight portion 510 for connecting the pressing portion 53 with the retention portion 52, and an inclined portion 512 formed between the retention portion 52 and the positioning portion 51. The retention portion 52 forms an arcuate surface 521 at a free end thereof for facilitating insertion of the retention portion 52 into the retention section 32 of the cover 3. The positioning portion 51 forms a barb 511 for securely engaging within a notch 2610 defined in an inner side wall of the groove 261 of the base 2.
Referring further to FIGS. 3 and 7, in assembly, the contacts 4 are inserted in the corresponding contact receiving passageways 21 of the base 2. The cover 3 is disposed on the top surface 27 of the base 2. The tabs 33 are aligned with the second platform 24, while the retention section 32 is aligned with the receiving slot 262 of the base 2. An IC package (not shown) is then positioned on the cover 3 so that pins of the IC package extend through the corresponding pin passageways 31 of the cover 3 into the corresponding contact receiving passageways 21 of the base 2 but do not electrically engage the contacts 4. The IC package and the cover 3 are then driven to move the distance "B" in the direction "A". Thus, the pins of the IC package electrically contact the corresponding contacts 4 received in the contact receiving passageways 21.
The retention member 5 is then fixed in the recess 26 from the bottom surface 28 of the base 2. The pressing portion 53 extends into the access cavity 25, the retention portion 52 extends through the receiving slot 262 of the base 2 into the retention section 32 of the cover 3, while the positioning portion 51 is disposed in the groove 261 and abuts against the inner side walls of the groove 261. The barb 511 securely engages within the notch 2610. Thus, the cover 3 and the IC package are secured to the base 2 with the pins of the IC package contacting the corresponding contacts 4.
To remove the IC package, the external tool 7 is required. The barb 511 of the positioning portion 51 works as a pivot about which the retention member 5 pivotally moves within the base 2. The tool 7 is operated to downwardly press the pressing portion 53 of the retention member 5, the main body 50 and the pressing portion 53 will occur resilient deformations and is simultaneously driven to pivotally downwardly move about the barb 511 of the positioning portion 51, while the retention portion 52 is driven to deflect and withdrawn from the retention section 32 of the cover 3, and the positioning portion 51 remains still within the groove 261. The receiving slot 262 of the base 2 is large enough for deflections of the retention portion 52 of the retention member 5 therein. Thus, the cover 3 and the IC package are released to move along the top surface 27 of the base 2 in the direction "A".
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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A zero insertion force (ZIF) socket comprises a dielectric base defining a number of contact receiving passageways for receiving a number of contacts therein and forming a pair of platforms outwardly extending from opposite lateral edges thereof, a slidable cover defining a number of pin receiving passageways for receiving corresponding pins of an IC package therein, and a resilient retention member received in one of the platforms of the base for locking the cover with the base in position thereby ensuring excellent electrical connection between the IC package and the ZIF socket.
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BACKGROUND OF THE INVENTION
The present invention relates to the processing of clay minerals and, more particularly, is directed to the processing of kaolinitic clays at high solids under acidic conditions to produce an improved paper filler composition.
It is well known that the incorporation of clay-based filler compositions into the paper web during the formation of paper sheet can significantly improve the optical properties of the resultant paper sheet. This improvement in opacity of the paper sheet by means of incorporation of the clay filler is the result of increased light scattering due primarily to the difference in indices of refraction between the filler, the paper fiber and air, and also due to the increased number of light scattering voids formed in the paper web upon the incorpoation of a clay filler. In order for the clay filler to perform well in improving opacity of the paper, the particle size distribution within the clay filler must be such that a large percentage of the clay particles have equivalent spherical diameters of between 0.6 and 1.5 microns and contain minimal particles with equivalent spherical diameters larger than 45 microns. Further, the paper maker must provide a paper product which meets customer specifications as to color shade. As it is customary to use dyes to obtain the desired paper color, the clay filler should have a good brightness consistent color, preferably showing good whiteness and little red, green, yellow or blue shade.
Unfortunately, very few kaolinitic clays in their crude state have the particle size distribution, the brightness or the color characteristics which are required for a good paper filler composition. For example, although tertiary kaolin clays mined in East Georgia have a fairly good particle size distribution in the crude state, they usually have low brightness and are highly colored. Their coloration varies widely ranging from grey-white to cream to brown to yellow to pink to purple. Additionally, a typical mine pit will contain up to about 60% of a clay having too low a brightness for processing under conventional prior art processes. Accordingly, such East Georgia tertiary kaolins are not, at present, widely used to make paper filler for white paper production.
It has become customary in the industry to beneficiate the crude kaolinitic clays used in clay filler compositions for paper making to improve particle size distribution and also improve color characteristics by removing ferric ion-containing compounds in the clay. Such ferric ion-containing compounds impart a non-white color to the clay and reduce the overall brightness or reflectance to visible light of the clay. It is well known that the effect of these ferric ion-containing compounds may be reduced by treating the clay with a reducing agent which converts the ferric ion to the less highly colored ferrous ion. A variety of reducing agents are known to be suitable for treating kaolinitic clays, but the most commonly used reducing agents are water-soluble dithionites or sulphites, such as sodium dithionite, zinc dithionite, sodium bisulphite, sodium hydrosulphite, and sodium pyrosulphite.
In the conventional process for reducing the ferric iron-containing impurities in a kaolinitic clay to the ferrous state, a low solids aqueous suspension of the crude clay is first formed, then if desired, degritted to remove large particles, and then treated with a reducing agent to convert the ferric ions therein to the ferrous state. The ferrous ion Is generally very soluble in water and will pass into the water in which the clay is suspended. The treated clay is then thickened, dewatered by filtration and the resultant filter cake thermally dried to produce a clay filler product having a high solids content, at least about 65%, suitable for economic transport. Such a low solids content process requires that the clay suspension be in a fluid state, that is, that the solids content of the crude clay suspension be less than about 50% by weight and usually in the range of 20% to 35% by weight. Unfortunately, such low solids processing of the crude kaolin requires that significant dewatering and drying be required to ready the treated clay product for economic transport. Significant economic benefits would be obtained if the crude kaolin clay could be processed at a high solids content, that is, at least about 65% by weight, so that the dewatering and subsequent drying of the treated clay could be minimized if not eliminated.
One such process for treating kaolinitic clays at high solids is disclosed in U.S. Pat. No. 4,186,027. As disclosed therein, a suspension of raw kaolinitic clay is formed in water at a solids content of 60% to 75% and at a pH in the range of from 7.0 to 11.0 with a dispersing agent. The fluid suspension of clay containing the dispersing agent is then treated with a water-soluble bleaching agent under alkaline pH conditions for a time sufficient to give the desired improvement and brightness of the clay. The treated clay product is said to not require any dewatering prior to shipment. This patent teaches that the suspensions must be prepared at a pH in the range of 7 to 11 in that suspensions outside of that range are allegedly too viscous to be refined successfully in a scroll-type centrifuge to give a product which is substantially free of particles having an equivalent spherical diameter larger than 10 microns. A drawback of such a high solids processing of the kaolinitic clay at an alkaline pH is that most of the papermaking processes used in the United States are carried out under acidic conditions. Therefore, it would be necessary to add additional acidic compounds in the papermaking process to neutralize an alkaline clay filler material produced from clay processing at a alkaline pH as disclosed in U.S. Pat. No. 4,186,027. Additionally, the clay filler material produced at an alkaline pH does not have good viscosity stability in that the viscosity of the clay filler produced in accordance with that process shows a significant increase in viscosity over time in storage. Further, beneficiation at an alkaline pH does not result in significant color improvement over the color characteristics of the crude.
Recently, a process has been developed for beneficiating a crude kaolinitic clay mineral at high solids under acidic conditions to produce a clay filler for use in papermaking. As disclosed in commonly assigned U.S. patent application Ser. No. 513,888, of Mitchell H. Koppelman and Ingrid K. Migliorini, filed July 14, 1983, crude kaolin clay is blunged with water containing a dispersing agent consisting of a blend of from about 20% to about 50% by weight of a water-soluble carbonate, about 20% to about 50% by weight of a water-soluble polyacrylate, and from 0% to about 60% by weight of a water-soluble anionic phosphate, to form a high solids fluid aqueous clay suspension having an acidic pH less than 7.0. This clay suspension is then fractionated to reduce the percentage of particles therein larger than 45 microns to not more than 0.2% by weight. The fractionated clay suspension is treated with an aqueous alkaline leaching solution containing a water-soluble reducing agent at a treatment level ranging from 1 to 6 pounds of reducing agent per ton of dry clay to convert ferric ions to ferrous ions. The treated clay suspension has a solids content of at least 65% by weight, a low grit content, an acid pH, and a brightness of at least 84, and is suitable without further dewatering for use as a clay filler in making paper.
One problem associated with such high solids processing of clay slurries is that high treatment levels in the leaching step, that is, for treatment levels in the range of 4 to 6 or more pounds of reducing agent per ton of dry clay, the viscosity of the treated clay product is unstable, that is, the viscosity increases with shelf age, and is often too high, that is, greater than about 2000 centipoise at 10 rpm, for practical use in the papermaking process. Therefore, crude clays having a low brightness, and thus requiring high levels of reducing agent in order to yield an acceptable product from a brightness standpoint, cannot be processed in this manner since the viscosity of the resultant product will be too high and unstable.
Accordingly, it is an object of the present invention to provide an improved process for beneficiating crude kaolinitic clays of low brightness via leaching a slurry of the clay at a high solids content and at high leaching treatment levels to produce a paper filler product having a stable improved brightness and color characteristics and an acceptable and stable viscosity.
SUMMARY OF THE INVENTION
According to the present invention, there is provided an improved process for treating a crude kaolinitic clay mineral, particularly crude clay having a low brightness, at high solids level, to provide a paper filler having improved brightness and acceptable viscosity, the improvement comprising the post-leaching treatment of the clay product with an oxidizing agent to destroy free-radical byproducts which are produced in the leaching process at high treatment levels and which are believed to cause an unacceptable rise in the viscosity of the leached clay product.
A fluid aqueous suspension of crude kaolinitic material is formed having a solids content of at least about 55% by weight, and preferably in the range of 65% to 75% by weight, and containing a dispersing agent. After subjecting the suspension to a fractionation process to produce a slurry having a particle size of 92-95% finer than 2 microns, the fractionated suspension is treated with an aqueous leaching solution containing a water-soluble reducing agent and allowed to leach under acidic conditions for a sufficient time to increase the brightness and improve the coloration of the clay mineral therein. The suspension, after treatment with the leaching solution, is treated with an oxidizing agent to destroy free-radical byproducts which are produced in the leaching process at high treatment levels. The clay product having been treated with an oxidizing agent subsequent to leaching has a stable improved brightness and a reduced and stable viscosity which makes it acceptable as a paper filler.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 of the drawing illustrates the increase in brightness produced by leaching a clay slurry with a reducing agent; and
FIG. 2 of the drawing illustrates the adverse increase in viscosity attendant with leaching a clay slurry with a reducing agent without post-leaching oxidation as in the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention can perhaps be better understood with reference to the following examples and the discussion thereof presented hereinafter. These examples are to be regarded as illustrative, but not in any way limiting, of the present invention.
EXAMPLE 1
A crude kaolin clay (Califf crude) was blunged with an aqueous dispersing solution comprising a 0.33% sodium hexametaphosphate and 0.17% soda ash to form a 70-71% solids, based on dry weight, aqueous clay suspension. After screening through a 250 mesh screen, the 70%+ solids clay suspension was fractionated on a centrifuge to give a product slurry having a particle size of 92-95% finer than 2 microns. The product slurry from the fractionation step had a solids content of approximately 69%. To simulate leaching at treatment levels of zero, one, two, four and six pounds of reducing agent per ton of clay on a dry basis, appropriate amounts of sodium dithionite dissolved in 5 milliliters of water were added, per 100 grams clay on a dry basis, to samples of the 69% solids fractionated slurry, which reduced the solids content to 67%. Each sample of leached slurry was allowed to stand for 48 hours prior to removing for determining the predispersed brightness. Additional samples of each of the leached slurries were also taken at this point and dried to a solids content of 70% for use in determining the Brookfield viscosity of the leached slurry. Additional dispersant was added, when necessary, to maintain optimum dispersion.
The viscosity and brightness measurements for each of the clay suspension of Example 1 are recorded in Table I.
EXAMPLE 2
A crude kaolin clay (Wrens crude) was blunged with an aqueous dispersing solution comprising a 0.33% sodium hexametaphosphate and 0.17% soda ash to form a 70-71% solids, based on dry weight, aqueous clay suspension. After screening through a 250 mesh screen, the 70%+ solids clay suspension was fractionated on a centrifuge to give a product slurry having a particle size of 92-95% finer than 2 microns. The product slurry from the fractionation step had a solids content of approximately 69%. To simulate leaching at treatment levels of zero, four and six pounds of reducing agent per ton of clay on a dry basis, appropriate amounts of sodium dithionite dissolved in 5 milliliters of water were added to 100 grams, on a dry basis, of the 69% solids, fractionated slurry, which reduced the solids content to 67%. The leached slurry was allowed to stand for 48 hours prior to removing for a sample for use in determining the predispersed brightness. An additional sample of the leached slurry was also taken at this point and dried to a solids content of 70% for use in determining the Brookfield viscosity of the leached slurry. Additional dispersant was added, when necessary, to maintain optimum dispersion.
The viscosity and brightness measurements for each of the clay suspensions of Example 1 are recorded in Table I.
TABLE I______________________________________ Leaching Treatment Brookfield (pounds sodium Viscosity Predispersed AcidExample dithionite/ton (centipoise FlocculatedNo. of dry clay) at 10 rpm) Brightness______________________________________(1a) 0.0 550 81.0(1b) 1.0 800 82.4(1c)-Califf 2.0 900 83.3(1d) 4.0 1500 85.1(1e) 6.0 2660 85.8(2a) 0.0 650 79.6(2b)-Wrens 4.0 2600 83.0(2c) 6.0 9000 83.6______________________________________
The brightness and viscosity measurements for the clay slurries processed in Examples 1 and 2, recorded in Table I above, are shown graphically in FIGS. 1 and 2, respectively, as a function of leaching treatment level. As illustrated in FIG. 1, the brightness of the clay slurry is improved, as expected, via leaching with the brightness increasing with increased treatment levels at least up to the level of treatment of six pounds of sodium dithionite per ton of clay on a dry basis. However, as illustrated in FIG. 2, there is also an adverse effect on the rheological properties of the clay slurry attendant with such leaching when unreacted leaching agent and leaching byproducts are not removed by post-leaching oxidation and filtration. As seen in FIG. 2, the viscosity of the Califf clay slurry increased by a factor of about 4 from 550 centipoise at 10 rpm in an untreated state to 2660 centipoise at 10 rpm after leaching at a treatment level of 6.0 pounds sodium dithionite per ton of dry clay. Similarly, the viscosity of the Wrens clay slurry increased by a factor of almost 14 from 650 centipoise at 10 rpm in an untreated state to 9000 centipoise at 10 rpm after leaching at a treatment level of 6.0 pounds sodium dithionite per ton of dry clay. As will be illustrated hereinafter, this adverse increase in viscosity with leaching can be greatly reduced in accordance with Applicants' invention, while maintaining improved brightness, by post-leaching oxidation and filtration.
EXAMPLE 3
A crude kaolin clay (Califf crude) was blunged with an aqueous dispersing solution comprising 0.33% sodium hexametaphosphate and 0.17% soda ash to form a 70-71% solids, based on dry weight, aqueous clay suspension. After screening through a 250 mesh screen, the 70%+ solids clay suspension was fractionated on a centrifuge to give a product slurry having a particle size of 92-95% finer than 2 microns. The product slurry from the fractionation step had a solids content of approximately 69%. To simulate leaching at a treatment level of four pounds of reducing agent per ton of clay on a dry basis, 0.20 grams of sodium dithionite dissolved in 5 milliters of a 4% sodium hydroxide solution was added to 100 grams, on a dry basis, of the 69% solids, fractionated slurry. The leached slip had a pH of 7.5 and a solids content of 67%. The leached slurry was allowed to stand for 48 hours prior to removing for a sample for use in determining the predispersed brightness. An additional sample of the leached slurry was also taken at this point and dried to a solids content of 70% for use in determining the Brookfield viscosity of the leached slurry. Additional dispersant was added, when necessary, to maintain optimum dispersion. The leached slurry had a Brookfield viscosity of 2730 centipoise at 10 rpm and a predispersed brightness of 85.7.
EXAMPLE 4
A crude kaolin clay (Califf crude) was blunged with an aqueous dispersing solution comprising a 0.33% sodium hexametaphosphate and 0.17% soda ash to form a 70-71% solids, based on dry weight, aqueous clay suspension. After screening through a 250 mesh screen, the 70%+ solids clay suspension was fractionated on a centrifuge to give a product slurry having a particle size of 92-95% finer than 2 microns. The product slurry from the fractionation step had a solids content of approximately 69%. To simulate leaching at a treatment level of four pounds of reducing agent per ton of clay on a dry basis, 0.20 grams of sodium dithionite dissolved in 5 milliliters of a 2% solution of tetrasodium pyrophosphate was added to 100 grams, on a dry basis, of the 69% solids, fractionated slurry. The leached slurry had a pH of 6.7 and a solids content of 67%. The leached slurry was allowed to stand for 48 hours prior to removing a sample for use in determining the predispersed brightness. An additional sample of the leached slurry was also taken at this point and dried to a solids content of 70% for use in determining the Brookfield viscosity of the leached slurry. Additional dispersant was added, when necessary, to maintain optimum dispersion. The leached slurry had a Brookfield viscosity of 1920 centipoise at 10 rpm and a predispersed brightness of 85.3.
EXAMPLE 5
A crude kaolin clay (Califf crude) was blunged with an aqueous dispersing solution comprising a 0.33% sodium hexametaphosphate and 0.17% soda ash to form a 70-71% solids, based on dry weight, aqueous clay suspension. After screening through a 250 mesh screen, the 70%+ solids clay suspension was fractionated on a centrifuge to give a product slurry having a particle size of 92-95% finer than 2 microns. The product slurry from the fractionation step had a solids content of approximately 69%. To simulate leaching at a treatment level of four pounds of reducing agent per ton of clay on a dry basis, 0.20 grams of sodium dithionite dissolved in 5 milliliters of a 2% solution of potassium tripolyphosphate was added to 100 grams, on a dry basis, of the 69% solids, fractionated slurry. The leached slurry had a pH of 6.6 and a solids content of 67%. The leached slurry was allowed to stand for 48 hours prior to removing a sample for use in determining the predispersed brightness. An additional sample of the leached slurry was also taken at this point and dried to a solids content of 70% for use in determining the Brookfield viscosity of the leached slurry. Additional dispersant was added, when necessary, to maintain optimum dispersion. The leached slurry had a Brookfield viscosity of 1680 centipoise at 10 rpm and a predispersed brightness of 85.5.
EXAMPLE 6
A crude kaolin clay (Wrens crude) was blunged with an aqueous dispersing solution comprising a 0.33% sodium hexametaphosphate and 0.17% soda ash to form a 70-71% solids, based on dry weight, aqueous clay suspension. After screening through a 250 mesh screen, the 70%+ solids clay suspension was fractionated on a centrifuge to give a product slurry having a particle size of 92-95% finer than 2 microns. The product slurry from the fractionation step had a solids content of approximately 69%. To simulate leaching at a treatment level of four pounds of reducing agent per ton of clay on a dry basis, 0.20 grams of sodium dithionite dissolved in 5 milliliters of a 4% sodium hydroxide solution was added to 100 grams, on a dry basis, of the 69% solids, fractionated slurry. The leached slurry had a pH of 7.5 and a solids content of 67%. The leached slurry was allowed to stand for 48 hours prior to removing a sample for use in determining the predispersed brightness. An additional sample of the leached slurry was also taken at this point and dried to a solids content of 70% for use in determining the Brookfield viscosity of the leached slurry. Additional dispersant was added, when necessary, to maintain optimum dispersion. The leached slurry had a Brookfield viscosity of 3280 centipoise at 10 rpm and a predispersed brightness of 84.4.
EXAMPLE 7
A crude kaolin clay (Wrens crude) was blunged with an aqueous dispersing solution comprising a 0.33% sodium hexametaphosphate and 0.17% soda ash to form a 70-71% solids, based on dry weight, aqueous clay suspension. After screening through a 250 mesh screen, the 70%+ solids clay suspension was fractionated on a centrifuge to give a product slurry having a particle size of 92-95% finer than 2 microns. The product slurry from the fractionation step had a solids content of approximately 69%. To simulate leaching at a treatment level of four pounds of reducing agent per ton of clay on a dry basis, 0.20 grams of sodium dithionite dissolved in 5 milliliters of a 2% solution of tetrasodium pyrophosphate was added to 100 grams, on a dry basis, of the 69% solids, fractionated slurry. The leached slurry had a pH of 6.7 and a solids content of 67%. The leached slurry was allowed to stand for 48 hours prior to removing a sample for use in determining the predispersed brightness. An additional sample of the leached slurry was also taken at this point and dried to a solids content of 70% for use in determining the Brookfield viscosity of the leached slurry. Additional dispersant was added, when necessary, to maintain optimum dispersion. The leached slurry had a Brookfield viscosity of 2000 centipoise at 10 rpm and a predispersed brightness of 83.2.
EXAMPLE 8
A crude kaolin clay (Wrens crude) was blunged with an aqueous dispersing solution comprising a 0.33% sodium hexametaphosphate and 0.17% soda ash to form a 70-71% solids, based on dry weight, aqueous clay suspension. After screening through a 250 mesh screen, the 70%+ solids clay suspension was fractionated on a centrifuge to give a product slurry having a particle size of 92-95% finer than 2 microns. The product slurry. from the fractionation step had a solids content of approximately 69%. To simulate leaching at a treatment level of four pounds of reducing agent per ton of clay on a dry basis, 0.20 grams of sodium dithionite dissolved in 5 milliliters of a 2% solution of potassium tripolyphosphate was added to 100 grams, on a dry basis, of the 69% solids, fractionated slurry. The leached slurry had a pH of 6.6 and a solids content of 67%. The leached slurry was allowed to stand for 48 hours prior to removing a sample for use in determining the predispersed brightness. An additional sample of the leached slurry was also taken at this point and dried to a solids content of 70% for use in determining the Brookfield viscosity of the leached slurry. Additional dispersant was added, when necessary, to maintain optimum dispersion. The leached slurry had a Brookfield viscosity of 1400 centipoise at 10 rpm and a predispersed brightness of 83.6.
TABLE IIa__________________________________________________________________________Example Brookfield Viscosity at 24 hrs. Hercules Viscosity Predispersed AcidNo. Leaching Treatment (centipoise at 10 rpm) Stability Ratio Flocculated__________________________________________________________________________ Brightness 1d sodium dithionite in water 1500 1.6 85.13 sodium dithionite in 4% 2730 1.57 85.7sodium hydroxide solution4 sodium dithionite in 1920 1.25 83.3tetrasodium pyrophosphate5 sodium dithionite in potassium 1680 1.34 85.5tripolyphosphate__________________________________________________________________________
TABLE IIb__________________________________________________________________________Example Brookfield Viscosity at 24 hrs. Hercules Viscosity Predispersed AcidNo. Leaching Treatment (centipoise at 10 rpm) Stability Ratio Flocculated__________________________________________________________________________ Brightness 2b sodium dithionite in water 2600 1.80 83.06 sodium dithionite in 4% 3200 2.43 84.4sodium hydroxide solution7 sodium dithionite in 2000 1.25 83.2tetrasodium pyrophosphate8 sodium dithionite in potassium 1400 1.71 83.6tripolyphosphate__________________________________________________________________________
As seen in Table IIa and IIb for the two different crudes, the addition of a dispersing agent in conjunction with the leaching treatment by dissolving the leaching agent in an aqueous solution of the dispersing agent prior to treating the clay slurry therewith can result in an improvement in the brightness and the viscosity stability of the product.
In Table IIa for Califf clay, the product clay slurries of Examples 3, 4 and 5, prepared by leaching with an aqueous solution of four pounds of sodium dithionite dissolved, respectively, in sodium hydroxide, tetrasodium pyrophosphate, and potassium tripolyphosphate, are compared with the product clay slurry of Example 1d prepared by leaching with a solution of four pounds of sodium dithionite dissolved in water without the addition of any dispersing agent. Similarly, in Table IIb for Wrens clay, the product clay slurries of Examples 6, 7 and 8, prepared by leaching with an aqueous solution of four pounds of sodium dithionite dissolved, respectively, in sodium hydroxide, tetrasodium pyrophosphate, and potassium tripolyphosphate, are compared with the product clay slurry of Example 2b prepared by leaching with a solution of four pounds of sodium dithionite dissolved in water without the addition of any dispersing agent.
As can be seen in Tables IIa and IIb, the addition of the dispersing agents tetrasodium pyrophosphate or potassium tripolyphosphate to the leaching agent resulted in an improved brightness and greatly improved viscosity stability for both clays. The addition of tetrasodium pyrophosphate to the sodium dithionite leaching chemical resulted in the greatest improvement in viscosity stability, while the addition of potassium tripolyphosphate to the sodium dithionite leaching chemical resulted in the lowest viscosity product. The addition of sodium hydroxide to the leaching chemical resulted in the greatest improvement in brightness but also caused an unacceptable increase in both viscosity for both clays and also in viscosity instability for the Wrens clay.
Accordingly, in the preferred embodiment of the present invention, the leaching solution comprises an aqueous solution of a water-soluble leaching agent and a water-soluble anionic phosphate.
EXAMPLE 9
A crude kaolin clay (Califf crude) slurry was prepared in accordance with the procedure outlined in Example 5 and then further processed in accordance with the present invention with a post-leaching treatment with an oxidizing agent. More specifically, the leached slurry was allowed to stand for 48 hours prior to treating the leached slurry with an oxidizing agent by adding sodium perborate to the leached slurry at a treatment level of 0.1 grams of oxidizing agent per 100 grams of dry clay. Samples of the post-leaching treated clay slurry were taken for use in determining the spray dried brightness, the acid flocculated brightness, and the Brookfield viscosity. The post-leaching treated clay slurry had an acid flocculated brightness of 85.2, a spray dried brightness of 84.6, and a Brookfield viscosity at 10 rpms of 1650 centipoise after standing for 24 hours and of 2050 centipoise after standing for 2 weeks.
EXAMPLE 10
A crude kaolin clay (Califf crude) slurry was prepared in accordance with the procedure outlined in Example 5 and then further processed in accordance with the present invention with a post-leaching treatment with an oxidizing agent. More specifically, the leached slurry was allowed to stand for 48 hours prior to treating the leached slurry with an oxidizing agent by adding hydroxylamine hydrochloride to the leached slurry at a treatment level of 0.05 grams of oxidizing agent per 100 grams of dry clay. Samples of the post-leaching treated clay slurry were taken for use in determining the spray dried brightness, the acid flocculated brightness, and the Brookfield viscosity. The post-leaching treated clay slurry had an acid flocculated brightness of 85.45, a spray dried brightness of 85.25, and a Brookfield viscosity at 10 rpms of 1650 centipoise after standing for 24 hours and of 2200 centipoise after standing for 2 weeks.
EXAMPLE 11
A crude kaolin clay (Califf crude) slurry was prepared in accordance with the procedure outlined in Example 5 and then further processed in accordance with the present invention with a post-leaching treatment with an oxidizing agent. More specifically, the leached slurry was allowed to stand for 48 hours prior to treating the leached slurry with an oxidizing agent by adding Pennstop 2697 (N,N-diethylhydroxylamine) to the leached slurry at a treatment level of 0.15 grams of oxidizing agent per 100 grams of dry clay. Samples of the post-leaching treated clay slurry were taken for use in determining the spray dried brightness, the acid flocculated brightness, and the Brookfield viscosity. The post-leaching treated clay slurry had an acid flocculated brightness of 85.2, a spray dried brightness of 84.1, and a Brookfield viscosity at 10 rpms of 1680 centipoise after standing for 24 hours and of 1850 centipoise after standing for 2 weeks.
EXAMPLE 12
A crude kaolin clay (Wrens crude) slurry was prepared in accordance with the procedure outlined in Example 5 and then further processed in accordance with the present invention with a post-leaching treatment with an oxidizing agent. More specifically, the leached slurry was allowed to stand for 48 hours prior to treating the leached slurry with an oxidizing agent by adding Pennstop 2607 (N,N-diethylhydroxylamine) to the leached slurry at a treatment level of 0.15 grams of oxidizing agent per 100 grams of dry clay. Samples of the post-leaching treated clay slurry were taken for use in determining the spray dried brightness, the acid flocculated brightness, and the Brookfield viscosity. The post-leaching treated clay slurry had an acid flocculated brightness of 83.4, and a Brookfield viscosity at 10 rpms of 2500 centipoise after standing for 24 hours.
TABLE III__________________________________________________________________________ Brookfield Viscosity Predispersed Acid Post-Leaching (centipoise at 10 rpm) Hercules Viscosity Flocculated BrightnessExample No. Oxidizing Agent at 24 hrs. at 2 wks. Stability Ratio Brightness Stability__________________________________________________________________________ 5 NONE 1680 2050 1.34 85.5 1.3 9 sodium perborate 1650 2050 1.33 85.2 0.610 hydroxylamine 1860 2200 1.18 85.45 0.2 hydrochloride11 N,N--diethyl- 1680 1850 1.17 85.2 1.1 hydroxylamine 2c NONE 9000 -- -- 83.6 --12 N,N--diethyl- 2500 -- -- 83.4 -- hydroxylamine__________________________________________________________________________
As seen in Table III, a high quality clay product having good brightness and improved rheological properties can be obtained for both crude clays by treating the leached clay slurry with an oxidizing agent in accordance with the present invention to oxidize unreacted leaching agent and byproducts formed during the leaching process. Three specific oxidizing agents: sodium perborate, hydroxylamine hydrochloride, and N,N-diethylhydroxylamine were treated. The use of N,N-diethylhydroxylamine (Examples 11,12) resulted in clay products from both clays having a reduced viscosity, and a greatly improved viscosity stability, but about the same brightness and brightness stability, when compared to the clay products Produced from these clays (Examples 5 and 2c respectively) treated via the same processes through the leaching step but without post-leaching oxidation in accordance with the present invention.
The use of sodium perborate or hydroxylamine hydrochloride as the oxidizing agent for post-leaching oxidation in accordance with the present invention also resulted in clay products having improved brightness and rheological properties. The use of sodium perborate or hydroxylamine hydrochloride resulted in significantly improved brightness stability in the oxidized clay product. With sodium perborate as the oxidizing agent, a slight improvement in viscosity stability was also noted, while using hydroxylamine hydrochloride as the oxidizing agent resulted in a significant improvement in viscosity stability but at a slight increase in viscosity.
EXAMPLE 13
A crude kaolin clay (Califf crude) was blunged with an aqueous dispersing solution comprising a blend of 0.12 grams sodium polyacrylate, 0.25 grams sodium hexametaphosphate and 0.17 grams sodium carbonate, under optimum conditions, to form 60-65% solids suspension. The dispersed clay suspension was then fractionated on a centrifuge to give a product suspension having a particle size of 92-95% finer than 2 microns. After fractionation, the solids content was adjusted to 55% and 0.3 grams of sodium dithionite dissolved in 5 milliliters of water was added to 100 grams, on a dry basis, of the clay suspension to simulate leaching at a treatment level of six pounds of reducing agent per ton of clay on a dry basis. The fractionated clay suspension was also acidified with sulfuric acid to a pH of 3.0-3.5. After mixing for one hour, the leached clay suspension was filtered via high pressure filtration on a Baroid Filter Press to form a filter cake at 74% solids. This filter cake was then redispersed to form a 70% solids slurry. The leached clay had a predispersed brightness of 84.4 and a Brookfield viscosity of 10 rpm of 2840 centipoise after standing for 24 hours.
EXAMPLE 14
A crude kaolin clay (Califf crude) was blunged with an aqueous dispersing solution comprising a blend of 0.12 grams sodium polyacrylate, 0.25 grams sodium hexametaphosphate and 0.17 grams sodium carbonate, under optimum conditions, to form 60-65% solids suspension. The dispersed clay suspension was then fractionated on a centrifuge to give a product suspension having a particle size of 92-95% finer than 2 microns. After fractionation, the solids content was adjusted to 55% and 0.3 grams of sodium dithionite dissolved in 5 milliliters of water was added to 100 grams, on a dry basis, of the clay suspension to simulate leaching at a treatment level of six pounds of reducing agent per ton of clay on a dry basis. The fractionated clay suspension was also acidified with sulfuric acid to a pH of 3.0-3.5. The leached clay suspension was then subjected to post-leaching oxidation by adding 0.20 grams of Pennstop 2697 (N,N-diethylhydroxylamine) per 100 grams of dry clay. The post-leaching treated clay suspension was then filtered via high pressure filtration on a Baroid Filter Press to form a filter cake at 74% solids. This filter cake was then redispersed to form a 70% solids slurry. The post-leaching treated clay had a predispersed brightness of 84.0 and a Brookfield viscosity of 10 rpm of 1700 centipoise after standing for 24 hours.
EXAMPLE 15
A crude kaolin clay (Wrens crude) was blunged with an aqueous dispersing solution comprising a blend of 0.12 grams sodium polyacrylate, 0.25 grams sodium hexametaphosphate and 0.17 grams sodium carbonate, under optimum conditions, to form a 60-65% solids suspension. The dispersed clay suspension was then fractionated on a centrifuge to give a product suspension having a particle size of 92-95% finer than 2 microns. After fractionation, the solids content was lowered to 15% and the pH of the suspension was reduced with sulphuric acid to a pH of 2.5. The clay suspension was then leached by adding thereto 0.3 grams of sodium dithionite dissolved in 5 milliliters of water to 100 grams, on a dry basis, to simulate leaching at a treatment level of six pounds of reducing agent per ton of clay on a dry basis. After mixing for one hour, the leached clay suspension was filtered to remove excess sulfate ions, soluble iron impurities and leaching byproducts. The filtered clay product was then dried to a solids content of 70%. The leached clay had a predispersed brightness of 84.3 and a Brookfield viscosity at 10 rpm of 800 centipoise after standing for 24 hours.
EXAMPLE 16
A crude kaolin clay (Wrens crude) was blunged with an aqueous dispersing solution comprising a blend of 0.12 grams sodium polyacrylate, 0.25 grams sodium hexametaphosphate and 0.17 grams sodium carbonate, under optimum conditions, to form a 60-65% solids suspension. The dispersed clay suspension was then fractionated on a centrifuge to give a product suspension having a particle size of 92-95% finer than 2 microns. After fractionation, the solids content was adjusted to 55% and 0.3 grams of sodium dithionite dissolved in 5 milliliters of water was added to 100 grams, on a dry basis, of the clay suspension to simulate leaching at a treatment level of six pounds of reducing agent per ton of clay on a dry basis. The fractionated clay suspension was also acidified with sulfuric acid to a pH of 3.0-3.5. After mixing for one hour, the leached clay suspension was filtered via high pressure filtration on a Baroid Filter Press to form a filter cake having a 74% solids. This filter cake was then redispersed to form a 70% solids slurry. The leached clay had a predispersed brightness of 84.5 and a Brookfield viscosity at 10 rpm of 1400 centipoise after standing for 24 hours.
EXAMPLE 17
A crude kaolin clay (Wrens crude) was blunged with an aqueous dispersing solution comprising a blend of 0.12 grams sodium polyacrylate, 0.25 grams sodium hexametaphosphate and 0.17 grams sodium carbonate, under optimum conditions, to form 60-65% solids suspension. The dispersed clay suspension was then fractionated on a centrifuge to give a product suspension having a particle size of 92-95% finer than 2 microns. After fractionation, the solids content was adjusted to 55% and 0.3 grams of sodium dithionite dissolved in 5 milliliters of water was added to 100 grams, on a dry basis, of the clay suspension to simulate leaching at a treatment level of six pounds of reducing agent per ton of clay on a dry basis. The fractionated clay suspension was also acidified with sulfuric acid to a pH of 3.0-3.5. The leached clay suspension was then subjected to post-leaching oxidation by adding 0.225 grams of sodium perborate per 100 grams of dry clay. The post-leaching treated clay suspension was then filtered via high pressure filtration on a Baroid Filter Press to form a filter cake at 74% solids. This filter cake was then redispersed to form a 70% solids slurry. The post-leaching treated clay had a predispersed brightness of 84.6 and a Brookfield viscosity of 10 rpm of 700 centipoise after standing for 24 hours.
TABLE IVa__________________________________________________________________________ % Solids Post-Leaching Brookfield Viscosity at 24 hrs. Predispersed AcidExample No. At Leaching Oxidizing Agent (centipoise at 10 rpm) Flocculated Brightness__________________________________________________________________________13 60-65 NONE 2840 84.414 60-65 N,N--diethyl- 1700 84.4 hydroxylamine__________________________________________________________________________
TABLE IVb__________________________________________________________________________ % Solids Post-Leaching Brookfield Viscosity at 24 hrs. Predispersed AcidExample No. At Leaching Oxidizing Agent (centipoise at 10 rpm) Flocculated Brightness__________________________________________________________________________15 15 NONE 800 84.316 60-65 NONE 1400 84.517 60-65 sodium perborate 700 84.6__________________________________________________________________________
The advantage of the process of the preferred embodiment of the invention, as illustrated in Examples 14 and 17, wherein the clay slurry is leached at a high solids content of at least about 55% solids under acidic conditions and the resultant leached clay slurry is treated with an oxidizing agent and pressure filtered to produce a clay product having a solids content of at least 70% solids, is further evidenced by the viscosity and brightness improvements presented in Tables IVa and IVb, respectively, for the Califf and Wrens clays. The post-leaching oxidation of the clay slurry derived from the Califf clay with N,N-diethylhydroxylamine (Example 14) resulted in a clay product having a significantly lower viscosity and only slightly reduced brightness when compared to the product (Example 13) derived from treating the Califf clay in accordance with the high solids beneficiating method disclosed in U.S. patent application Ser. No. 513,888 of Mitchell H. Koppelman and Ingrid K. Migliorini, filed July 14, 1983, but without post-leaching oxidation. The post-leaching oxidation of the clay slurry derived from the Wrens clay with sodium perborate (Example 17) resulted in a clay product having not only a lower viscosity but also a slightly higher brightness when compared either to the product (Example 16) derived from treating the Wrens clay in accordance with the high solids beneficiating method disclosed in the aforementioned application of Koppelman and Migliorini or to the product (Example 15) derived from treating the Wrens clay via typical prior art processes at low solids.
Accordingly, it has been illustrated that even crude kaolin clays, which have generally heretofore been considered to be of poor quality from a rheological and brightness standpoint to be used for making paper filler, may be beneficiated in accordance with the present invention at high solids and high leaching levels with post-leaching oxidation and filtration to yield a clay filler material having a suitable viscosity and brightness for use in the papermaking process. Post-leaching oxidation in accordance with the present invention enables high leaching treatment levels to be used in the leaching process without an adverse increase in the viscosity and decrease in brightness and brightness stability in the product clay filler. Post-leaching oxidation results in the destruction by oxidation of unreacted leaching agent and leaching byproducts which heretofore have resulted in a degradation in brightness of the product clay filler during drying. Through the use of high solids leaching at high treatment levels followed by post-leaching oxidation and press filtration, poorer quality kaolin clays can be used to produce quality clay filler for the papermaking industry without going through the costly filtration and drying steps necessary under current technology not only to increase the solids content to a commercially acceptable level of 70%, but also to remove excess sulfate ions, soluble iron impurities and leaching agent byproducts which adversely affect viscosity, viscosity stability, brightness, and brightness stability.
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A process for beneficiating a poor grade crude kaloinitic clay mineral to produce a clay filler for use in papermaking to improve the brightness of the paper product. The crude kaolin clay is blunged with water containing a dispersing agent to form a high solids fluid aqueous clay suspension. This clay suspension is then screened and fractionated to reduce the particle size thereof to 92-95% finer than 2 microns. The fractionated clay suspension is treated with an alkaline leaching solution containing a reducing agent effective in converting ferric ions to ferrous ions and, preferably, a water-soluble anionic phosphate. The leached clay suspension, which has a solids content of at least 55%, is then treated with an oxidizing agent to oxidize unreacted leaching agent and byproducts formed during the leaching process.
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FIELD OF THE INVENTION
[0001] The present invention generally relates to semiconductor processing, and more specifically to a shield employed in a plasma processing system.
BACKGROUND
[0002] This invention concerns new types of shields to be used in a plasma vapor deposition (PVD) process chamber for the processing of wafers in, for example, the semiconductor industry or the magnetic recording disk drive industry. A PVD process chamber generally consists of a target, a plasma environment, a wafer that is to be film deposited, shields, and other chamber components. The target provides the source of material to be deposited onto the wafer. The plasma environment, facilitated by an energized gas, drives the deposition process of transferring the target material to the surface of the wafer. An undesirable side effect is that target material also deposits on other places inside the chamber. The shields are intended to provide an envelope to contain the depositing material that does not deposit on the wafer.
[0003] An ideal shield would retain unlimited amounts of deposited materials falling onto it and would not allow materials to emit from it since the substances leaving the shield are a source of contamination for the wafer. However, a shield in practice has a limited life which often determines the production time of a PVD chamber. Beyond the end of shield life, a large amount of deposited materials and other process residuals on a shield may generate internal stress high enough to exceed the strengths of bonded materials which causes flaking and or the emission of a substance off the shield. The emitted substance leaving the shield may land on the wafer and cause defects and/or yield loss.
[0004] Shield components commonly used in PVD process chambers are fabricated from metal or ceramic materials. For example, a PVD tantalum deposition chamber may include shields such as an upper floating shield, an inner shield, a lower shield, a shutter disk, a cover ring, a deposition ring and a clamp ring. Commonly, shields are fabricated from a substrate material of stainless steel due to its excellent mechanical and chemical properties as well as its low cost. Ceramic materials, such as alumina or zirconia, have also been used as shield substrates in some cases (e.g., deposition rings) where high electrical conductivity of the substrate is undesirable. Titanium has also been used as a substrate for some shields (e.g., cover rings or shutter disks) where the low thermal expansion characteristics of titanium are desired in shield components located very close to the wafer being processed. It is believed that the reduced thermal expansion of titanium compared to stainless steel may reduce the generation of contaminating particles due to the stress in the deposited material caused by the expansion.
[0005] The surface of the components in a PVD process chamber is often treated so as to improve the adhesion of the deposited material since many materials deposited by a PVD process (“deposition material”) do not adhere well to smooth metal or ceramic components. Roughening the surface often improves the adhesion of deposited material to the component. Such roughening may be accomplished by means such as grit-blasting. Further improvement in the adhesion of deposited material may sometimes be obtained by coating the component with another material, such as aluminum, as described, e.g., Micro Magazine in March 2001 by Rosenberg, and U.S. Pat. No. 6,227,435 issued on May 8, 2001, to Lazarz et al. Usually, the coating itself has a rough surface finish which helps improve the mechanical interlocking between the deposited material and the coating. Ductile coatings, like aluminum, may also help to dissipate through plastic deformation a portion of the accumulated stress from the overlying deposited material. As long as the coating adheres well to the substrate material of the component, a substantial amount of deposited material can be accumulated without unduly contaminating wafers that are being processed. Typically, rough metal coatings may be applied to component surfaces by thermal spray methods such as twin-wire arc spraying or plasma spraying.
[0006] Once a certain amount of deposited material (which may incorporate other process residuals) has been accumulated on the shield components in a process chamber, the operation of the process chamber must cease temporarily until the shield components are replaced. If production continued without replacing the shield components, defective wafers would be produced due to contamination from material emitted from the shield components. Frequently, the sputtering target is replaced at the same time as the shield components are replaced to minimize lost production time of the costly equipment.
[0007] After replacing the shield components, and possibly the sputter target, the deposition chamber must be conditioned before production of wafers can continue. Often such chamber conditioning consists of a pump-down and bake-out procedure, followed by a target burn-in procedure. A typical pump-down and bake-out procedure evacuates the air in the chamber by means of vacuum pumps, thus reducing the pressure in the chamber. Then, the interior of the chamber and interior components may be heated above ambient temperature to hasten the achievement of even lower chamber pressures. Once a sufficiently low chamber pressure has been achieved, a target burn-in procedure sputters material from the surface of the target to prepare the target suitably for production processing. Often, the entire process of replacing the shield components and the sputtering target, then performing the pump-down and bake-out procedure, and then performing the target burn-in procedure may take many hours, e.g., 6 to 18 hours. Since this chamber conditioning process represents lost production time, it is desirable to minimize the total time spent on these activities.
[0008] One way to reduce the lost production time associated with replacement of shield components and/or sputtering targets is to reduce the time used for either or both of the chamber conditioning steps. For example, target burn-in is sometimes performed by alternating periods of deposition (“plasma on”) with periods during which the plasma is off. This “plasma-off” time may be needed to prevent the chamber or some of its components from being heated by the plasma to a temperature high enough to cause damage. However, if the percentage of “plasma off” time can be decreased, the total non-productive time of the equipment would be reduced.
[0009] It has been found; however, that shield components made according to standard methods may fail when such an approach is taken to reducing the target burn-in time. For example, if the ratio of “plasma on” to “plasma off” times of the burn-in procedure is increased from about 1.05 to about 1.38 when standard shield components fabricated from stainless steel coated with an aluminum arc spray coating are used in a typical PVD chamber for depositing tantalum, the shields fail much earlier than normal. The shields fail not during the burn-in procedure, but later during routine wafer processing. In other words, the burn-in procedure is completed without incident and normal production processing of wafers is started. After processing less than about one third of the number of wafers usually processed between shield replacements, the shield's aluminum coating and overlying deposition material delaminate over large areas of the shield. This failure forces immediate replacement of the shield components and also may result in scrapped wafers.
[0010] Since the interior chamber components exposed to the plasma are heated by the plasma, shortening of “plasma-off” times during the burn-in procedure causes these components to rise to a higher temperature. Since most of the shield components are poorly cooled, the maximum temperatures reached can be quite high. Analysis on shields that delaminated early after experiencing a fast burn-in cycle discovered a layer of an aluminum-iron-nickel intermetallic phase formed at the interface between the stainless-steel substrate and the aluminum are spray coating. This observation is consistent with published Fe—Al—Ni ternary phase diagram which indicated the formation of the Al—Fe—Ni intermetallic phase above about 400° C., as described by Guha et al. on Materials Characterization 34:181-188 published in 1995. When coupons made from stainless steel coated with aluminum arc spray were heated to various temperatures and then analyzed, they exhibited the same type of intermetallic phase after exposure to temperatures above about 400° C.
[0011] It was also observed that adjacent to the intermetallic phase layer, a region with a large population of voids of a few micrometers in size is formed in the aluminum spray coating. Such a high-porosity layer was not observed in either shields or coupons only subjected to temperatures lower than 400° C. The formation of the voids is thought to be a result of local depletion of aluminum atoms (or collections of atomic vacancies) that diffused into the intermetallic phase layer as the intermetallic phase layer grows. Similar observations of such pore formation were also found in solid-state reaction studies on other bi-materials, as described, e.g., Schmalzried in Solid-State Reaction published in 1981. This intermetallic phase layer with a large population of voids weakens the adhesion between the aluminum arc spray coating and the underlying stainless steel substrate, thus leading to delamination.
[0012] In the case of a PVD wafer process with a fast burn-in cycle, shields which attain a temperature above approximately 400° C. will contain an intermetallic phase layer and a void-populated layer after the burn-in. As a result, these shields will have a reduced cohesive strength between the aluminum arc spray coating and the stainless steel substrate. Upon the subsequent wafer processing, deposition materials and other process residuals accumulate on the surface of the shields and the internal stress increases, thereby acting to pull the aluminum coating apart from the stainless steel substrate along the weakened and void-populated layer. As a result, this prior art shield will fail at lower internal stress before its normal chamber life due to delamination along the weakened layer.
[0013] Thus, it is desirable to obtain a shield component, that after exposure to the higher temperatures caused by a shortened burn-in procedure, which is capable of operating for a normal number of wafers without excessive contamination to those wafers.
[0014] Nothing in the prior art provides the benefits attendant with the present invention.
[0015] Therefore, it is an object of the present invention to provide an improvement which overcomes the inadequacies of the prior art devices and which is a significant contribution to the advancement of the semiconductor processing art.
[0016] Another object of the present invention is to provide a shield component for a plasma processing system comprising a substrate, a reaction barrier layer, and a top coating.
[0017] Yet another object of the present invention is to provide a shield component for a plasma processing system comprising a substrate and a coating wherein said substrate does not chemically react with said coating to form a new intermetallic phase at a temperature range of about 400 to 660° C.
[0018] The foregoing has outlined some of the pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
[0019] The present invention provides a process shield for a PVD process chamber that can be exposed to temperatures above about 400° C. (but below the melting temperature of aluminum around 660° C.) without substantial weakening of the adhesion between the coating and the substrate (or intermetallic phase formation at the substrate-coating interface). Thus, the shields of the present invention can be used, for example, in a PVD process chamber utilizing a fast burn-in cycle to gain more wafer production time without sacrificing shield life. The invented shields have two embodiments to satisfy different deposition, refurbishment and economic requirements, i.e., a double coating embodiment and a single coating embodiment.
[0020] In regard to the double coating embodiment, the shield has a substrate material of stainless steel, a reaction barrier layer and a twin-wire arc sprayed top coating. The reaction barrier layer has a thickness of about 0.001 to about 0.010 inches that covers over the grit-blasted textured stainless steel substrate. The reaction barrier layer can be produced by a thermal spray method such as a plasma spray or a twin-wire arc spray or by a plating method. The reaction barrier layer comprises at least one of the following materials: titanium, a non-magnetic nickel-chromium alloy (major constituents of around 70% by weight of nickel and around 20% by weight of chromium) or a non-magnetic cobalt-chromium-molybdenum alloy (major constituents of around 60% by weight of cobalt, around 26% by weight of chromium and around 7% by weight of molybdenum). The top coating has a thickness of about 0.005 to about 0.020 inches or, more preferably, about 0.008 to about 0.012 inches which covers over the reaction barrier layer and comprises aluminum. The top coating can be applied by a thermal spray method such as a twin-wire arc spray or a plasma spray.
[0021] The material (Ti, Ni—Cr alloy or Co—Cr—Mo alloy) for the reaction barrier layer is so chosen that it will not lead to an intermetallic phase formation between the stainless steel substrate and the barrier layer or between the aluminum top coating and the barrier layer at temperatures in the range of about 400 to 660° C. In addition, the reaction barrier layer will not reduce the adhesion strength between the two interfaces. Thus, in comparison to a prior art shield whose mechanical property deteriorates after subjecting it to a temperature above about 400° C., the new shield of the present invention can be used at extended chamber temperatures without sacrificing shield life. Furthermore, the material used for the reaction barrier layer is non-magnetic. Thus, the addition of this reaction barrier layer does not affect the shield's RF or magnetic characteristics.
[0022] When coating the stainless steel substrate with the reaction barrier material of the present invention, it is desirable to maintain a minimum thickness of at least about 0.001 inches so as to maintain the barrier function of this layer. Also, it is desirable for the surface roughness of the reaction barrier layer to be greater than about 300 microinches to ensure adequate adhesion to the top coating when fabricating the top coating by thermal spray. Depending on spray angle between the normal of spray surface and the axis of the spray gun and on spray parameters (e.g., carrier gas pressure), the surface roughness average of the top coating typically lies between about 1000 to about 2000 microinches for arc spray or between about 500 and about 1000 microinches for plasma spray.
[0023] In regard to the single coating embodiment, the shield consists of a substrate material and a coating with substrate-coating material combinations chosen to allow no new intermetallic phase to form at the substrate-coating interface at elevated temperatures of around 400 to around 660° C. The following substrate-coating material combinations are used:
(1) The shield has a substrate material of stainless steel and a thermal-spray coating of around 0.005 to around 0.020 inches thick or, more preferably, about 0.008 to about 0.012 inches thick of one of the following materials: titanium, a non-magnetic nickel-chromium alloy (major constituents of around 70% by weight of nickel and around 20% by weight of chromium) or a non-magnetic cobalt-chromium-molybdenum alloy (major constituents of around 60% by weight of cobalt, around 26% by weight of chromium and around 7% by weight of molybdenum); (2) the shield has a substrate material of titanium and a thermal-spray coating of aluminum with a thickness around 0.005 to around 0.020 inches thick or, more preferably, about 0.008 to 0.012 inches thick; or (3) the shield has a substrate material of aluminum and a thermal-spray coating of titanium with a thickness around 0.005 to around 0.020 inches thick or, more preferably, about 0.008 to about 0.012 inches thick.
[0027] The material combinations between the substrate and coating as stated above do not lead to intermetallic phase formation at temperatures around 400 to around 660° C. and do not show thermal degradation of coating-to-substrate adhesion strength. The coating to substrate adhesion strengths of the shields of the present invention is equal or greater than that of a stainless steel-aluminum interface in a prior art shield. In comparison to prior art shields, whose mechanical property deteriorates above 400° C., the invented shields can be used at extended chamber temperatures without sacrificing shield life. Furthermore, the coating materials used on the shields of the present invention are non-magnetic and thus, will not introduce complications concerning its RF or magnetic characteristics.
[0028] The thermal spray coatings can be fabricated using a plasma spray process or a twin-wire arc spray process. Depending on spray angle between the surface normal and spray gun axis and on spray parameters, the coating surface roughness typically lies between around 500 to around 1000 microinches for a plasma spray process and the coating surface roughness typically lies between around 1000 to around 2000 microinches for a twin-wire arc spray process. The high surface roughness of the spray coating will allow a large amount of deposition materials to adhere to the shields.
[0029] The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The drawings illustrate partial sectional side views of the structure of the invented shield and of an example of a PVD process chamber in which the invented shields are used. It is to be understood that the drawings illustrate only typical embodiments of the invention and are not to be considered limiting in their scope.
[0031] FIG. 1 depicts a partial sectional side view of an example PVD chamber using the invented shields for at least one of the following components: an upper shield, an inner shield, a lower shield, a shutter disk, a cover ring and a clamp ring;
[0032] FIG. 2 is a partial sectional side view of the layer structure of a PVD chamber shield having a substrate material, a reaction barrier layer over the substrate and a top coating layer according to one embodiment of the present invention;
[0033] FIG. 3A is a partial sectional side view of the layer structure of a PVD chamber shield having a thermal spray coating over a substrate material of stainless steel according to one embodiment of the present invention;
[0034] FIG. 3B is a partial sectional side view of the layer structure of a PVD chamber shield having a thermal spray coating over a substrate material of titanium according to one embodiment of the present invention; and
[0035] FIG. 3C is a partial sectional side view of the layer structure of a PVD chamber shield having a thermal spray coating over a substrate material of aluminum according to one embodiment of the present invention.
[0036] Similar reference characters refer to similar parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0037] The invented PVD process chamber shield 10 (or PVD process chamber component) has enhanced thermal and mechanical stabilities and is used to contain deposition materials or residuals generated in the PVD process chamber. As an example, FIG. 1 illustrates a partial sectional side view of a PVD tantalum deposition chamber 20 . In this illustration, the chamber shields 10 include an upper floating shield 11 , an inner shield 12 , a lower shield 13 , a shutter disk 14 and a cover ring 15 . The current invention can apply to one or all of these shields components. Since each shield component experiences a different heating effect from the chamber plasma; however, different shields may reach different temperatures during operation.
[0038] The present invention discloses two embodiments of shields. The first embodiment of shield 50 , as illustrated in FIG. 2 , consists of a stainless steel substrate material 52 , a reaction barrier layer 60 and a top aluminum thermal spray coating 70 . To fabricate the first embodiment of shield 50 , a machined or a refurbished stainless steel part 52 is first cleaned; for example, in an alkaline cleaner bath with ultrasonic excitation and rinsed, for example in deionized water. Then, the surface 54 of the stainless steel substrate 52 to be coated is roughened; for example, by grit blasting. The grit blast process is performed by blasting a hard medium, such as aluminum oxide beads, toward the stainless steel surface 54 using compressed clean dry air. The purpose of the grit blast surface treatment is to roughen the stainless steel surface 54 to a desirable surface roughness average above about 150 microinches. The stainless steel surface 54 roughness is an important parameter affecting the adhesion between the stainless steel substrate 52 and coating materials since mechanical interlocking is one of the key adhesion mechanisms. The size of the aluminum oxide beads may be selected to achieve the desired roughness. Typical bead sizes are about mesh size 46 or about mesh size 24. Also, the pressure of the blasting air may be selected so as to achieve the desired surface roughness. Typically, air pressures from about 40 to about 80 psi may be used.
[0039] A reaction barrier layer 60 is then applied on the top of at least one portion of the grit-blasted textured stainless steel surface 54 . A preferred method of producing the reaction barrier layer 60 is by a plasma spray or a twin wire arc spray. The material for the reaction barrier layer 60 comprises at least one of the following materials: titanium, a non-magnetic nickel-chromium alloy (major constituents of around 70% by weight of nickel and around 20% by weight of chromium) or a non-magnetic cobalt-chromium-molybdenum alloy (major constituents of around 60% by weight of cobalt, around 26% by weight of chromium and around 7% by weight of molybdenum). The average thickness of this barrier layer 60 is preferably from around 0.001 to around 0.010 inches thick or, more preferably, about 0.003 to 0.005 inches thick. When coating the stainless steel substrate 52 with the reaction barrier material 60 , it is desirable to maintain a minimum thickness of at least about 0.001 inches so as to maintain the barrier function of this barrier layer 60 . Also, it is desirable for the surface 62 roughness of the reaction barrier layer 60 to be greater than about 300 microinches to ensure adequate adhesion to the top coating 70 . An aluminum top coating 70 is applied on the surface 62 of the reaction barrier layer 60 . The top coating 70 is applied by a thermal spray method on the barrier layer 60 . A preferred method for the thermal spray coating 70 is the use of a plasma spray process or a twin-wire arc spray process to generate a coating 70 having a thickness around 0.005 to around 0.020 inches thick or, more preferably, about 0.008 to about 0.012 inches thick. Depending on spray angle between the surface normal and spray gun axis and on spray parameters, the surface 72 roughness of the coating 70 lies between around 500 to around 1000 microinches for a plasma spray process, and the surface 72 roughness of the coating 70 lies between around 1000 to around 2000 microinches for a twin-wire arc spray process. These surface 72 roughness values are desirable to allow a large amount of deposition materials to adhere to this first embodiment of shields 50 .
[0040] The material for the reaction barrier layer 60 is so chosen that it will not lead to intermetallic phase formation between the substrate 52 and the barrier layer 60 or between the top coating 70 and the barrier layer 60 at temperatures in the range of about 400 to around 660° C. In addition, the reaction barrier layer 60 will not reduce the adhesion strength between the two interfaces. In comparison to a prior art shield, whose mechanical property deteriorates after subjecting to a temperature above about 400° C., the new shield 50 can be used at extended chamber temperatures without sacrificing shield life. The material used for the reaction barrier layer 60 is non-magnetic and the addition of this layer 60 does not affect the shield's RF or magnetic characteristics.
[0041] The second embodiment of shield 100 , as illustrated in FIGS. 3A to 3C , consists of a substrate 102 and a coating 110 , with substrate-coating material 102 combinations chosen to allow no new intermetallic phase to form at the substrate-coating interface. The following materials combinations are used:
(1) As shown in FIG. 3A , the shield 100 A has a substrate material 102 A of stainless steel and a thermal-spray coating 110 A of around 0.005 to around 0.020 inches thick or, more preferably, about 0.008 to about 0.012 inches thick of one of the following materials: titanium, a non-magnetic nickel-chromium alloy (major constituents of around 70% by weight of nickel and around 20% by weight of chromium) or a non-magnetic cobalt-chromium-molybdenum alloy (major constituents of around 60% by weight of cobalt, around 26% by weight of chromium and around 7% by weight of molybdenum); (2) As shown in FIG. 313 , the shield 100 B has a substrate material 102 B of titanium and a thermal-spray coating 110 B of aluminum with a thickness around 0.005 to around 0.020 inches thick or, more preferably, about 0.008 to about 0.012 inches thick; or (3) As shown in FIG. 3C , the shield 100 C has a substrate material 102 C of aluminum and a thermal-spray coating 110 C of titanium with a thickness around 0.005 to around 0.020 inches thick or, more preferably, about 0.008 to about 0.012 inches thick.
[0045] To fabricate the second embodiment of shield 100 ( 100 A, 100 B or 100 C), a machined or a refurbished shield 100 with one of the above substrate materials 102 ( 102 A, 102 B or 102 C) is first ultrasound cleaned; for example, in an alkaline cleaner bath with ultrasonic excitation and rinsed; for example, in deionized water. Then, the surface 104 ( 104 A, 104 B or 104 C) of the substrate 102 to be coated is roughened; for example, by grit blasting. The grit blast process is performed by blasting a hard medium, such as aluminum oxide beads, toward the surface 104 using compressed clean dry air. The purpose of the grit blast surface treatment is to roughen the surface 104 to a desirable surface roughness average above about 150 microinches. The surface roughness 104 is an important parameter affecting the adhesion between the substrate 102 and coating materials 110 ( 110 A, 110 B or 110 C) since mechanical interlocking is one of the key adhesion mechanisms. The size of the aluminum oxide beads may be selected to achieve the desired roughness. Typical bead sizes are about mesh size 46 or about mesh size 24. Also, the pressure of the blasting air may be selected so as to achieve the desired surface roughness. Typically, air pressures from about 40 to about 80 psi may be used.
[0046] The coating 110 is applied by a thermal spray method on at least one portion of the grit blasted surfaces 104 of the substrate material 102 , A preferred method for the thermal spray coating 110 is the use of a plasma spray process or a twin-wire arc spray process to generate a coating 110 having a thickness around 0.005 to around 0.020 inches thick or, more preferably, about 0.008 to about 0.012 inches thick. Depending on spray angle between the surface normal and spray gun axis and on spray parameters, the surface 112 ( 112 A, 112 B or 112 C) roughness of the coating 110 lies between around 500 to around 1000 microinches for a plasma spray process, and the surface 112 roughness of the coating 110 lies between around 1000 to around 2000 microinches for a twin-wire arc spray process. These surface 112 roughness values are desirable to allow a large amount of deposition materials to adhere to this second embodiment of shields 100 .
[0047] The material combinations between the substrate 102 and the coating 110 for this second embodiment of shield 100 of the present invention do not lead to intermetallic phase formation at temperatures around 400 to around 660° C. and do not show thermal degradation of the coating-to-substrate adhesion strength. The adhesion strength of these bi-materials is equal or greater than that of an aluminum-stainless steel interface in a conventional shield. In comparison to prior art shields, whose mechanical property deteriorates above around 400° C., the invented shield can be used at extended chamber temperatures without sacrificing shield life. Furthermore, the coating materials used are non-magnetic and thus, will not introduce complication concerning its RF characteristics.
[0048] A widely used thermal spray coating method is a twin-wire arc spray. In this method, two metal wires connected to different polarities of an electrical power supply are brought in proximity to trigger an electrical arcing and to melt two metal wires that are consumable. At the same time, a compressed carrier gas (normally a clean dry air) atomizes and propels the molten metal away from the arc gun and projects the melt onto a surface to be coated. The molten or partially molten metal droplets impact on the surface of a shield and solidify to form units (lamellae) of a thermal spray coating. The two metal wires are continuously fed to sustain the coating process. The rate of deposition is proportional to the wire feed rate that increases with the set value of electrical current. The surface roughness of the coating is mainly determined by the pressure of the carrier gas and by the spray angle (the angle between the axis of the spray gun and the normal of the surface to be coated). The arc spray gun can be attached to a robot that is then programmed to produce a consistent and uniform coating for a given geometry of a shield.
[0049] Plasma spray is another commonly used thermal spray method. Plasma spray involves the generation of a plasma flame facilitated by pressurized and an electrically energized gas mixture such as argon-hydrogen or argon-helium. The plasma flame can generate a high temperature zone (as high as 20,000° K) with high heat content and thus, can spray materials of high melting temperature. A powder port located adjacent to the plasma flame continuously feeds powders of the coating material to the flame. The powder particles entering the plasma flame get melted or partially melted and at the same time are propelled by the pressurized plasma flame towards the surface to be coated. The molten or partially molten droplets impact and solidify at the surface, forming units of the coating with their thermal and kinetic energies partially transforming to the energy of adhesion to the underlying substrate. The powder feed can be controlled to a given rate to yield a certain coating rate for a given speed of gun movement that can be controlled using a robot. A uniformly sized powder can be used to produce a coating with a uniform surface morphology. In comparison to arc spray, plasma spray is generally more expensive and yields a less rough surface with more uniform surface morphology and can coat both metal and ceramic materials.
[0050] The thickness of a thermal spray coating can be measured by a variety of techniques, such as using microscopy analysis on a cross-section sample, using a micrometer to determine sample or part thickness before and after coating and using commercially available coating thickness gages. The surface roughness average of a coating can be measured using a surface profilometer which involves scanning a surface by a diamond tip to generate a surface morphology profile. A recognized ASME/ANSI B46.1-2002 standard is used to define the measurement of the surface roughness average. For a surface roughness average greater than 400 microinches, a cut-off length of 0.3 inches is used.
[0051] The strength of adhesion of a coating to a substrate material is evaluated by an adhesion pull test. In a pull test, the coating with a given area is attached by an epoxy to a piston of a tester. The underlying substrate material is attached to the other piston of a tester by an epoxy or by a pin through a hole made in the substrate material. The tester's two pistons are then uniaxially pulled apart at a given rate of displacement. The force or stress acting on the pistons is recorded continuously. The minimum stress that is required to cause the delamination of the coating from the substrate is taken as the strength of adhesion of the coating to the substrate. To accurately determine the adhesion, the epoxy is so chosen that the strength of the bulk epoxy and the strength of adhesion of epoxy to the coating are much greater than the strength of adhesion of the coating to the substrate.
[0052] The impact of high temperature on the adhesion strength was evaluated for different combinations of substrate and coating materials used in the two embodiments of invented shields, as well as for aluminum-stainless steel bi-material samples representing the conventional shield. Coupons of these material combinations were prepared and were heat-treated at 250° C., 350° C., 450° C. and 550° C. under vacuum for one hour. Adhesion pull tests were then carried out on these samples as well as on samples without heat treatment. All samples representing the coating-substrate material combinations for the invented shields yielded similar adhesion strength of 7 to 9 kpsi for the different heat treatment temperatures. The strengths are similar to the strength of 7-8 kpsi for the samples of aluminum-stainless steel bi-material representing the conventional shield when no heat treatment was performed, but are much greater than that of 3 to 4 kpsi for the conventional shield samples when heat treatment at 450° C. and 550° C. was performed.
[0053] Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to analyze cross sectional metallurgical specimens. The specimens were prepared by cutting samples perpendicular to the coating to include the bi-material interface(s) and by subsequent fine polish. The analysis on the heat-treated samples determines if intermetallic phase(s) forms at the interface(s). Based on the SEM-EDS observations on cross section of the invented shield, no intermetallic phase was observed at any of the bi-material interfaces for the two embodiments of invented shields after the shields had been heated above 400° C. This is in contrast to the conventional aluminum coated stainless steel shield for which SEM-EDS analysis on samples after experiencing a fast burn-in cycle or being heat-treated above 400° C. revealed that, as a result of the excess heating, a layer of aluminum-iron-nickel intermetallic phase formed at the interface between the stainless-steel substrate and the aluminum arc spray coating. Associated with the intermetallic phase formation, it was also observed that adjacent to the intermetallic layer, a region with large population of voids is formed in the aluminum spray coating. Such a porous layer was not observed in shields or coupons that were only subjected to temperatures lower than 400° C. This layer with large population of voids weakens the aluminum are spray coating adhesion to the underlying stainless steel substrate.
[0054] The first embodiment of the invented shields use a reaction barrier layer that prohibits the intermetallic phase layer formation between stainless steel and aluminum. The second embodiment of invented shields use material combinations that any intermetallic phase would not be thermodynamically stable to form at the interface. The invented shield materials have thermal and structural stability, as well as good bulk and interface strengths to outperform the conventional aluminum arc sprayed stainless steel shields of the prior art during PVD processes requiring elevated chamber temperature.
[0055] The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.
[0056] Now that the invention has been described,
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The invented shield components are used for a plasma processing system to adhere deposition materials or process residuals during wafer processing, thus preventing excessive wafer contamination, even when exposed to high temperatures. One embodiment of the invented shields consists of a reaction barrier layer to separate the underlying substrate from the overlying spray coating to prevent solid-state chemical reaction between the substrate and the coating. Another embodiment of the invented shields consists of a substrate and a coating with a substrate-coating combination chosen to allow no new solid-state phase to form at the interface. The invented shields have well-bonded materials interfaces that preserve thermal and mechanical stability under high temperature conditions in a plasma processing system for the containment of deposition contaminates.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a Continuation of Ser. No. 12/699,116; filed Feb. 3, 2010; which is a Divisional of U.S. application Ser. No. 10/788,064 filed Feb. 26, 2004; issued as U.S. Pat. No. 7,786,238 on Aug. 31, 2010; which claims priority to German Application 10308753.2; all of which are hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
The present invention relates to cationic starch graft copolymers which are suitable for increasing the dry strength of paper, their use and their preparation.
The dry strength of paper covers various strength parameters which are determined on the dry paper, such as dry tensile strength, bursting strength, cleavage strength or strength in the z direction, stiffness, buckling resistance and surface strength (cf. “Dry Strength Additives”, Ed. W. F. Reynolds, TAPPI Press 1980, Atlanta). For increasing the dry strength, certain additives can be added to paper. The dry strength is determined primarily by hydrogen bridges within the paper sheet, in addition to the natural strength of the cellulose fibres themselves. Polymeric, hydrophilic additives which can form hydrogen bridges with the cellulose fibres and thus increase the contact area between the cellulose fibres have therefore proved useful. Typical examples of these are starch, galactomannans, polyacrylamides, carboxymethylcellulose and polyvinyl alcohol.
Additives for increasing the dry strength, i.e. dry strength agents, can be added to the paper pulp and/or applied to the surface of the paper. For use in the pulp, either cationic, self-retaining polymers are employed or anionic or amphoteric polymers are used in combination with a cationic fixing agent. In the case of surface use, the charge plays no role for the fixing, so that virtually uncharged polymers, such as polyvinyl alcohol, can also be used here. Starches and galactomannans which are used as dry strength agents in the pulp are usually cationically modified. Polyacrylamides are used in anionic, amphoteric or cationic form, amphoteric or anionic polyacrylamides usually being combined with a fixing agent when used in the pulp in order to achieve good retention in the paper.
U.S. Pat. No. 4,400,496 describes graft polymers based on starch and acrylamide, starch serving as the grafting base and the grafts either consisting only of acrylamide, i.e. being nonionic, or being composed of acrylamide and acrylic acid, i.e. being anionic. If they are added as dry strength agents to the paper pulp, such products must be combined with a fixing agent in order to ensure sufficient retention. EP-A 194 987 describes cationic starch graft polymers as paper dry strength agents, starch being used as grafting base and the grafts consisting of cationic polyacrylamide fragments. This is achieved by grafting on acrylamide together with a cationic vinyl monomer. The products described can be used without a fixing agent in the paper pulp since they have sufficient intrinsic retention owing to the cationic charge. A significant increase in the dry breaking strength is achieved thereby.
DESCRIPTION OF THE INVENTION
It has now surprisingly been found that cationic starch graft polymers whose grafts preferably predominantly comprise acrylamide and/or methacrylamide can be further improved in their action as dry strength agents if crosslinking agents having a functionality of 2 or higher are concomitantly used during the graft polylmerization of acrylamide or methacrylamide, cationic vinyl monomer and optionally further monofunctional vinyl monomers.
The present invention therefore relates to cationic starch graft polymers comprising the monomers a) to d)
a) 20-80% by weight of acrylamide, methacrylamide or mixtures thereof, b) 3-20% by weight of at least one basic or cationic vinyl monomer, c) 0.005-1.5% by weight of at least one bifunctional or higher-functional crosslinking agent, d) 0-10% by weight of at least one nonionic or anionic vinyl monomer which differs from the monomers mentioned under a) to c)
and a grafting base e)
e) 15-70% by weight of at least one starch or one starch derivative,
the sum of a) to e) being 100% by weight.
The starch graft polymers according to the invention are obtainable by free radical polymerization of monomers a) to d) in the presence of the grafting base e).
Acrylamide, methacrylamide and any desired mixtures of these two monomers are suitable as monomers mentioned under a). Pure acrylamide is preferably used.
Vinyl compounds which have a double bond capable of free radical polymerization and which either carry a permanently cationic charge, e.g. in the form of an ammonium group, or contain a basic group which is present in at least partly protonated form even under weakly acidic (pH 2.5-6) conditions are suitable as monomers mentioned under b). For example, N,N-dialkylaminoalkyl acrylates or methacrylates or N,N-dialkylaminoalkylacrylamides or -methacrylamides and the respective quaternization products thereof can be used. Specific examples of these are N,N-dimethylaminoethyl acrylate, N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl acrylate, N,N-diethylaminoethyl methacrylate, N,N-dimethylaminopropylacrylamide, N,N-dimethylaminopropylmethacrylamide and the corresponding quaternary ammonium salts which can be prepared from the abovementioned compounds, for example by reaction with customary quaternizing reagents, such as methyl chloride, dimethyl sulphate, epichlorohydrin or benzyl chloride, such as, for example, 2-(acryloyloxy)ethyltrimethylammonium chloride, 2-(methacryloyloxy)ethyltrimethyl-ammonium chloride, 3-(acrylamido)propyltrimethylammonium chloride, 3-(methacrylamidopropyl)trimethylammonium chloride, 2-(acryloyloxy)ethylbenzyl-dimethyl-ammonium chloride and 2-(methacryloyloxy)ethylbenzyldimethylammonium chloride. Further examples of suitable monomers mentioned under b) are vinylpyridine and diallyldimethylammonium chloride. Permanently cationic monomers are preferably used. 2-(Acryloyloxy)ethyltrimethylammonium chloride, 2-(methacryloyloxy)ethyltrimethyl-ammonium chloride and diallyldimethylammonium chloride are particularly preferred here.
For example, those having a water solubility of at least 3 g/l at 23° C. are suitable monomers mentioned under c), for example divinyl compounds, such as N,N′-methylenebisacrylamide, ethylene glycol diacrylate and ethylene glycol dimethacrylate. N,N′-Methylenebisacrylamide is preferably used.
Nonionic or anionic vinyl compounds, such as, for example, styrene, acrylic esters, methacrylic esters, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, N-vinylformamide, hydroxyethyl acrylate or methacrylate, and furthermore esters of acrylic acid or methacrylic acid which can be obtained by reaction with at least 2 equivalents of ethylene oxide, and acrylic acid, methacrylic acid, itaconic acid, maleic anhydride, vinyl sulphonic acid and styrenesulphonic acid, are suitable as monomers mentioned under d). However, the amount of the monomers mentioned under d) is preferably <3% by weight, based on the sum of a) to e).
If an anionic monomer mentioned under d) is used, the amount in relation to the amount of the cationic monomer under b) is chosen so that not more than 0.66 mol of anionic monomer, based on 1 mol of cationic monomer, is used. Exclusively products having an excess cationic charge are thus obtained.
Preferably, starches based on potato starch, rice starch, wheat starch, maize starch or tapioca starch are suitable as starches mentioned under e). Usually, starches whose molecular weights have already been reduced by partial degradation and/or which have been obtained by derivatization are preferably used instead of natural starches. Furthermore, starches for which both modification steps have been combined, i.e. which have been partially degraded and additionally derivatized, are suitable. Typical methods for starch degradation are, for example, enzymatic, oxidative, thermal or hydrolytic treatment. Examples of suitable starch derivatives are hydroxyethyl starch or cationic starch. Cationic starch is understood as meaning in general starch ethers which contain quaternary ammonium groups. In the context of the present invention, hydroxyethyl starch and cationic starch are preferred, and predegraded cationic starches, each having a degree of substitution DS of >0.01, are particularly preferred.
The polymerization is usually carried out in an aqueous medium in the neutral to acidic pH range, preferably in the pH range 2.5-6. The pH can be adjusted to a suitable value before the beginning of the polymerization by adding small amounts of mineral acids or organic acids, such as, for example, hydrochloric acid, sulphuric acid, phosphoric acid, formic acid or acetic acid. As a rule, the starch is initially introduced completely in aqueous suspension or solution and the other monomers are either added in the batch process or in the feed process and reacted in a free radical polymerization by means of suitable initiators. EP-A 194 987 describes, as a typical process, initially introducing the glutenized starch, and nonionic and cationic monomer in the form of a mixture and initiating the polymerization by adding an initiator and carrying out said polymerization.
The invention therefore also relates to a process for the preparation of the starch graft polymer according to the invention, which is characterized in that the components a) to e) are subjected to free radical polymerization in water in the presence of free radical initiators.
The invention furthermore relates to a process for the preparation of a cationic starch graft polymer, characterized in that the monomers a) to d)
a) 20-80% by weight of acrylamide, methacrylamide or mixtures thereof b) 3-20% by weight of at least one basic or cationic vinyl monomer c) 0-1.5% by weight of at least one bifunctional or higher-functional crosslinking agent d) 0-10% by weight of at least one nonionic or anionic vinyl monomer which differs from the monomers mentioned under a) to c)
are subjected to free radical polymerization in the presence of
e) 15-70% by weight of at least one starch or one starch derivative,
characterized in that, in a first step, the component e), as the grafting base, is subjected to free radical polymerization in water with at least 30% by weight of the total amount of the component b) and then, in a second step, the other components a), c), d) and the remaining amount of b) are subjected to free radical polymerization in the presence of the reaction mixture formed in the first step, and the sum of a) to e) is 100% by weight.
The invention also relates to cationic starch graft polymers obtainable by this process.
This two-stage process is preferably carried out in such a way that, in a first step, the vinyl monomer mentioned under b) is subjected to free radical polymerization by addition of an initiator in the presence of the component mentioned under e), the reaction temperature being at least 70° C., the duration of polymerization being at least 15 min and the amount of initiator being at least 2.0% by weight, based on the total amount of the monomer mentioned under b); and, in a second step, the remaining monomers are reacted in the presence of the reaction mixture formed.
The starch initially introduced in water is preferably heated to a value above its glutenization temperature before the first polymerization step is started. The customary temperature range for both polymerization steps is 70-100° C. The temperature may also be higher if a pressure-resistant reactor under superatmospheric pressure is employed. The customary duration of polymerization for the first step is 0.25-1.5 h and that for the second step is 0.5-4 h. The monomers and initiators can in each case be added in one or in several portions over the duration of polymerization, or can also be metered in continuously. Polymerization is carried out in an inert gas atmosphere, e.g. under nitrogen.
Initiators used for the polymerization are in general free radical initiators, preferably peroxo or azo compounds. Examples of these are hydrogen peroxide, sodium, potassium and ammonium peroxodisulphate, di-tert-butyl peroxide, dibenzoyl peroxide, azobisisobutyronitrile, 2,2′-azobis(2-methylbutyronitrile), 2,2′-azobis(2,4-dimethylvaleronitrile) and 2,2′-azobis(2-amidinopropane)dihydrochloride. Preferred among these are initiators having a water solubility of >1% by weight at 23° C., such as, for example, hydrogen peroxide and potassium and ammonium peroxodisulphate.
Furthermore, so-called redox initiator systems, in which said free radical initiators are used together with a reducing agent, are suitable as initiators. Examples of suitable reducing agents are sodium sulphite, sodium pyrosulphite, sodium hydrogen sulphite, sodium dithionite, sodium formaldehyde sulphoxylate and ascorbic acid. In addition, said free radical initiators can also be combined with heavy metal salts, such as cerium(IV), manganese or iron salts to give a suitable redox system. Ternary initiator systems consisting of free radical initiator, reducing agent and heavy metal salt are furthermore suitable.
If a binary redox system comprising free radical initiator and reducing agent is used, the reducing agent is preferably initially introduced before the beginning of the polymerization. An amount of 2.0-4.5% by weight, based on the total amount of monomer b), of free radical initiator is preferably used for the first polymerization step.
In general, the reaction conditions are preferably chosen so that at least 50% by weight of the monomer b) are reacted during the first polymerization step of the two-stage process. The conversion at the end of the first step can be determined by the methods known to a person skilled in the art, such as, for example, HPLC or 1 H-NMR spectroscopy.
During the entire preparation process, the reaction mixture is usually thoroughly mixed by means of suitable stirring or mixing units so that the added components are homogeneously distributed as rapidly as possible. After the end of the addition of the monomers and the initiator of the second polymerization step, the reaction mixture is usually allowed to continue reacting for some time in order to complete the polymerization. After this subsequent reaction time, a certain amount of initiator is preferably added again in order to polymerize as substantially as possible the residual monomers still present in the reaction mixture. After a further subsequent reaction time, the pH of the resulting polymer solution can be adjusted by adding suitable bases. A value in the range 4-7 is preferably established thereby, and preferred bases are alkali metal hydroxides and alkali metal acetates. Furthermore, buffer substances may also be added in order to stabilize the pH over the storage time.
The concentration of the graft polymer solutions prepared by the two-stage process is preferably 5-25% by weight and in particular 12-22% by weight. The viscosity of the resulting solutions is preferably <5 000 mPa·s measured at 23° C. by means of a rotational viscometer.
In order to increase the shelf-life of the resulting polymer solutions, a biocide may be added at the end of the preparation process in order to achieve effective protection from fungal and bacterial attack. Biocides based on isothiazolinones or benzoisothiazolinones, or formaldehyde-donating biocides, are preferably added for this purpose.
The cationic starch graft polymers according to the invention are suitable in principle for ensuring the dry strength of all customary papers, it being possible both to use them in the pulp, i.e. to add them to the paper stock prior to sheet formation, and to apply them to the surface of the paper web, for example by means of a size press or film press or by spraying.
The majority of the customary paper stock systems consist of fibres, mineral fillers and water. There are also filler-free stock systems. Suitable fibres in the context of the invention are all customary types, such as bleached and unbleached, wood-free and wood-containing, wastepaper-containing and deinked stocks. Examples of customary fillers are kaolin, natural or precipitated CaCO 3 , talc and titanium dioxide.
In a preferred embodiment, the polymers according to the invention are used in the pulp and owing to their cationic charge, are substantially absorbed onto the cellulose fibres. The polymers according to the invention can be used both in the acidic and in the neutral procedure. The customary added amounts (calculated as polymeric solid) are 0.05-2% by weight, based on dry paper stock. Optionally, the polymers according to the invention can also be combined with temporary or permanent wet strength agents, with the result that development of increased wet and dry strength is achieved. The polymers according to the invention are very suitable for combination with cationic wet strength agents. Examples of these are urea/or melamine/formaldehyde resins, polyamine/or polyamidoamine/epichlorohydrin resins, glyoxalated cationic polyacrylarrudes, as described, for example, in U.S. Pat. No. 4,605,702, and hydrophilized polyisocyanates, as described, for example, in EP-A 582 166/EP-A 944 886.
In a further preferred embodiment, the polymers according to the invention are applied to the surface of the paper web, usually by means of suitable application units, such as a size press or film press. The customary added amounts (calculated as polymeric solid) are 0.05-2% by weight, based on dry paper stock. In this application, the polymers according to the invention can be combined with other customary paper chemicals which are used in the surface, in particular with starches and surface sizes. Less suitable is the combination with anionic optical brighteners, since the brightener effect is reduced by the cationic polymer. When brighteners are concomitantly used, nonionic and/or cationic brighteners are preferably employed. Furthermore, the polymers according to the invention can also be combined with the temporary or permanent wet strength agents described above, also in the case of surface application, if it is also desired to increase the wet strength in addition to increasing the dry strength.
In addition to increasing the dry strength, i.e. the dry tensile strength, bursting strength, cleavage strength, stiffness and buckling resistance, the polymers according to the invention are also very suitable for reducing dusting and picking, which is advantageous for the printability in a number of customary printing processes. Furthermore, the dry strength agents according to the invention are suitable for use in pulp for improving the retention of fillers and of fines and for accelerating drainage. In addition, the dry strength agents according to the invention can advantageously be combined with the synthetic engine sizes alkylketene dimer (AKD) and alkenylsuccinic anhydride (ASA), since they promote the retention of these products when used in the pulp and can also act as so-called cationic promoters; i.e. can accelerate the reaction of AKD or ASA with the cellulose fibre.
Compared with the products frequently used for increasing the dry strength and based on glyoxalated polyacrylamides, the dry strength agents according to the invention have the advantage of a substantially increased shelf-life.
EXAMPLES
Preparation Examples
(all stated percentages are % by weight, unless stated otherwise)
For all preparation examples, cationic potato starches whose molecular weight had been reduced were used. Specifically, the starches used had the following features with regard to the method of molecular weight reduction and degree of substitution with cationic groups:
Method of reduction
Degree of substitution DS
Starch A
Oxidative
0.018
Starch B
Oxidative
0.027
Starch C
Oxidative
0.018
Examples 1-6 illustrate the preparation of cationic starch graft copolymers crosslinked according to the invention. Examples 7-14 illustrate the two-stage process according to the invention for the preparation of cationic starch graft copolymers which are likewise according to the invention.
Example 1
1 007 g of demineralized water are initially introduced at room temperature into a 2 1 plane-ground flask having jacket heating and a stirrer, and 50.5 g of starch A (solids content 82.2%) are suspended therein with stirring. The apparatus is then placed under nitrogen. Nitrogen atmosphere and stirring are maintained for the entire further reaction sequence.
The starch suspension is heated to 85° C., the starch glutenizing and forming a slightly turbid solution. After 85° C. have been reached, stirring is continued for 15 min and then 0.5 g of glacial acetic acid is added. Thereafter, the following two solutions are metered in uniformly and simultaneously over 90 min at 85° C.:
Feed 1): Aqueous solution of the monomers consisting of:
78.2 g of acrylamide
23.35 g of 2-(acryloyloxyethyl)trimethylammonium chloride as an 80% strength aqueous solution (AETAC)
3.0 g of a 1% strength aqueous solution of N,N′-methylenebisacrylamide (MBA)
100.0 g of demineralized water
Feed 2): Aqueous solution of the initiator, consisting of:
96.9 g of a 2% strength aqueous solution of ammonium peroxodisulphate
After the end of the metering operations, stirring is continued for 45 min at 85° C., after which 15.0 g of a 2% strength aqueous solution of ammonium peroxodisulphate are added for subsequent activation. Stirring is effected for a further 45 min at 85° C., after which the polymer solution is cooled to room temperature.
The pH is adjusted to 7.1 with about 7 g of 10% strength sodium hydroxide solution, and furthermore 1.4 g of a biocide (PREVENTOL® D 2, Bayer AG) are added. Finally, the polymer solution is filtered through a 100 μm polyamide filter cloth.
A moderately viscous, clear, homogeneous polymer solution is obtained.
Example 2
The procedure is as in example 1, but other amounts of initially introduced water and N,N′-methylenebisacrylamide are used:
Initially introduced demineralized water
995.0 g
1% strength aqueous solution of MBA
15.0 g
Example 3
The procedure is as in example 1, but 50.7 g of the starch B (81.9% solids content) are used.
Example 4
The procedure is as in example 2, but 50.7 g of the starch B (81.9% solids content) are used.
Example 5
The procedure is as in example 1, but 48.5 g of the starch C (85.6% solids content) are used. In contrast to example 1, 1 009 g of demineralized water are initially introduced.
Example 6
The procedure is as in example 2, but 48.5 g of the starch C (85.6% solids content) are used. In contrast to example 2, 997 g of demineralized water are initially introduced.
Example 7
1 031 g of demineralized water are initially introduced into a 2 1 plane-ground flask having jacket heating and a stirrer at room temperature, and 49.9 g of the starch A (solids content 83.1%) are suspended therein with stirring. The apparatus is then placed under nitrogen. Nitrogen atmosphere and stirring are maintained for the entire further reaction sequence.
The starch suspension is heated to 85° C., the starch glutenizing and forming a slightly turbid solution. After 85° C. have been reached, stirring is continued for 15 min, after which 0.5 g of glacial acetic acid and 23.4 g of an 80% strength aqueous solution of AETAC are added. For initiation of the 1st polymerization stage, the following solution is metered in uniformly over 30 min at 85° C.:
Feed 1): Aqueous initiator solution consisting of:
24.2 g of a 2% strength solution of ammonium peroxodisulphate
After completion of feed 1, the 2nd polymerization stage is carried out. For this purpose, the following solutions are metered in uniformly over 90 min at 85° C.:
Feed 2): Aqueous acrylamide solution consisting of:
78.2 g of acrylamide
80.0 g of demineralized water
Feed 3): Aqueous initiator solution consisting of:
72.7 g of a 2% strength solution-of ammonium peroxodisulphate
After the end of the metering operations, stirring is continued for 45 min at 85° C., after which 15.0 g of a 2% strength aqueous solution of ammonium peroxodisulphate are added for subsequent activation. Stirring is effected for a further 45 min at 85° C., after which the polymer solution is cooled to room temperature.
The pH is adjusted to 7.1 with about 7 g of 10% strength, sodium hydroxide solution and furthermore 1.4 g of the biocide PREVENTOL® D 2 (Bayer AG) are added. Finally, the polymer solution is filtered through a 100 μm polyamide filter cloth.
A slightly viscous, clear, homogeneous polymer solution is obtained.
Example 8
The procedure is analogous to example 7, but a metering time of 60 min is chosen for feed 1 and a metering time of 60 min for the simultaneous feeds 2 and 3.
Example 9
The procedure is analogous to example 7, but the solution of AETAC is metered in uniformly and simultaneously with feed 1 over 30 min.
Example 10
The procedure is analogous to example 7, but a different composition of the polymer is chosen. Specifically, in contrast to example 7, the following amounts are used:
Starch A (solids content 83.1′%)
66.6
g
Demineralized water (initially introduced)
1 049
g
AETAC as 80% strength aqueous solution
13.0
g
Feed 1
20.8
g
Feed 2:
Acrylamide
72.65
g
Demineralized water
75.0
g
Feed 3
62.3
g
Example 11
The procedure is analogous to example 7, but the starch B is used. In contrast to example 7, the following amounts are used:
Starch B (solids content 81.9%) 50.7 g Demineralized water (initially introduced) 1030 g
For a sample taken after the end of the 1st polymerization stage, a monomer conversion of 62% was determined by means of 1 H-NMR.
Example 12
The procedure is analogous to example 7, but the starch C is used. In contrast to example 7, the following amounts are used:
Starch C (solids content 85.6%)
48.5
g
Demineralized water (initially introduced)
1032
g
Example 13
826 g of demineralized water are initially introduced at room temperature into a 2 1 plane-ground flask having jacket heating and a stirrer, and 101.3 g of starch B (solids content 81.9%) are suspended therein with stirring. The apparatus is then placed under nitrogen. Nitrogen atmosphere and stirring are maintained for the entire further reaction sequence.
The starch suspension is heated to 85° C., the starch glutenizing and forming a slightly turbid solution. After 85° C. have been reached, stirring is continued for 15 min and then 0.6 g of glacial acetic acid, 6.0 g of a 5% strength aqueous solution of Rongalit® C (sodium formaldehyde sulphoxylate dihydrate) and 46.7 g of an 80% strength aqueous solution of AETAC are added. For initiation of the 1st polymerization stage, the following solution is metered in uniformly over 30 min at 85° C.:
Feed 1): Aqueous initiator solution consisting of:
48.5 g of a 2% strength solution of ammonium peroxodisulphate
After completion of feed 1; the 2nd polymerization stage is carried out. For this purpose, the following solutions are metered in uniformly over 90 min at 85° C.:
Feed 2): Aqueous acrylamide solution consisting of:
156.4 g of acrylamide
165.0 g of demineralized water
Feed 3): Aqueous initiator solution consisting of:
145.3 g of a 2% strength solution of ammonium peroxodisulphate
After the end of the metering operations, stirring is continued for 45 min at 85° C., after which 30.0 g of a 2% strength aqueous solution of ammonium peroxodisulphate are added for subsequent activation. Stirring is effected for a further 45 min at 85° C., after which the polymer solution is cooled to room temperature.
The pH is adjusted to 7.0 with about 11 g of 10% strength sodium, hydroxide solution, and furthermore 1.6 g of the biocide PREVENTOL® D 2 (Bayer AG) are added. Finally, the polymer solution is filtered through a 100 μm polyamide filter cloth.
A moderately viscous, clear, homogeneous polymer solution is obtained.
Example 14
The procedure is analogous to example 7, but a different composition of the polymer is chosen. Specifically, in contrast to example 7, the following amounts are used:
Demineralized water (initially introduced)
1 016
g
Feed 2:
Acrylamide
78.2
g
1% strength aqueous solution of MBA
15.0
g
Demineralized water
80.0
g
Example 15
Comparative Example Analogous to EP-A 194 987
1 014 g of demineralized water are initially introduced at room temperature into a 2 1 plane-ground flask having jacket heating and a stirrer, and 50.5 g of starch A (solids content 82.2%) are suspended therein with stirring. The apparatus is then placed under nitrogen. Nitrogen atmosphere and stirring are maintained for the entire further reaction sequence.
The starch suspension is heated to 85° C., the starch glutenizing and forming a slightly turbid solution. After 85° C. have been reached, stirring is continued for 15 min and then 0.5 g of glacial acetic acid is added. Thereafter, the following two solutions are metered in uniformly and simultaneously over 90 min at 85° C.:
Feed 1): Aqueous solution of the monomers consisting of:
78.2 g of acrylamide
23.35 g of AETAC as an 80% strength aqueous solution (AETAC)
100.0 g of demineralized water
Feed 2): Aqueous solution of the initiator, consisting of:
96.9 g of a 2% strength aqueous solution of ammonium peroxodisulphate
After the end of the metering operations, stirring is continued for 45 min at 85° C., after which 15.0 g of a 2% strength aqueous solution of ammonium peroxodisulphate are added for subsequent activation. Stirring is effected for a further 45 min at 85° C., after which the polymer solution is cooled to room temperature.
The pH is adjusted to 7.1 with about 7 g of 10% strength sodium hydroxide solution, and furthermore 1.4 g of the biocide PREVENTOL® D 2 (Bayer AG) are added. Finally, the polymer solution is filtered through a 100 μm polyamide filter cloth.
A moderately viscous, clear, homogeneous polymer solution is obtained.
TABLE 1
Physical parameters of the polymer solutions of
examples 1-15
pH
Solids content
Viscosity* at 23° C.
Example
established
(%)
(mPa · s)
1
7.1
10.3
390
2
7.3
10.2
90
3
7.1
10.3
120
4
7.1
10.3
100
5
7.0
10.0
60
6
7.0
10.2
3000
7
7.1
10.0
20
8
7.0
10.0
25
9
7.0
9.9
20
10
7.1
10.1
90
11
7.0
9.9
10
12
7.0
9.9
20
13
7.0
18.1
260
14
7.0
10.0
20
15
7.1
10.3
150
*measured using a Haake VT 5L rotational viscometer (L3 spindle)
Use Examples
(The stated amounts in the following examples are specified as percentages by weight, unless stated otherwise. All stated amounts represent the content of dry polymer, based on dry paper.)
0.5% or 1.5% of each of the polymers from the preceding preparation examples were added with stirring to a wastepaper-containing stock suspension having a consistency of about 5 g/l, prepared from rebeaten, CaCO 3 -containing lining cardboard. After a mixing time of 2.5 minutes, 0.2% of a retention. aid (RETAMINOL E, Bayer AG) was added. After a further mixing time of 10 s, sheets were formed using a Rapid-Koethen laboratory sheet former. These were dried for 7 min in the connected dryer and then conditioned overnight at 23° C. and 50% relative humidity. The ash content of the laboratory sheets without polymer addition, determined by ashing at about 900° C., was 11-13%. The basis weights of the sheets formed were in the range 65-85 g/m 2 .
The sheets thus formed measured with regard to dry tensile strength using an apparatus from Frank and with regard to the bursting strength using an apparatus from Lorentzen & Wettre. From these data, the relative increase in the dry tensile strength and in the bursting strength was calculated, relative to a comparative sample without addition of a corresponding dry strength agent. The following formula, which is shown here by way of example for the dry tensile strength, was used for the calculation:
Relative increase in the dry tensile strength = Δ DTS = ( SDTA Test sample - SDTS Zero sample ) SDTS Zero sample · 100 [ % ]
where:
SDTS=Standardized dry tensile strength in N Zero sample=Laboratory sheet without dry strength agent Test sample=Laboratory sheet with dry strength agent to be tested
All measured values of the dry tensile strength and of the bursting strength were based on a basis weight of 80 g/m 2 , with the result that five standardized dry tensile strength was calculated from the measured dry tensile strength:
Standardized dry tensile strength = SDTS = ( DTS · BW ) 80
where:
DTS=Measured value of the dry tensile strength BW=Basis weight of the associated laboratory sheet in g/m 2
Analogous procedures were used for calculating the standardized bursting strength or the relative increase in the bursting strength.
The values for the relative increase in the dry tensile strength (ΔDTS) or the relative increase in the bursting strength (ΔBS) are listed in table 2.
TABLE 2
Strength parameters of papers which were treated
with polymer solutions from examples 1-15
Added amount
Δ DTS
Δ BS
Example
(%)
(%)
(%)
1
0.5
6.3
24.5
1.5
20.7
40.1
2
0.5
9.8
25.0
1.5
22.5
36.6
3
0.5
7.7
16.5
1.5
21.6
30.1
4
0.5
3.9
21.2
1.5
19.7
35.8
5
0.5
6.3
19.9
1.5
22.8
32.2
6
0.5
17.4
18.5
1.5
20.7
35.3
7
0.5
11.4
22.9
1.5
30.9
40.5
8
0.5
17.9
26.6
1.5
34.6
37.9
9
0.5
16.3
17.6
1.5
30.2
35.9
10
0.5
10.7
23.4
1.5
18.5
32.4
11
0.5
25.0
27.6
1.5
23.2
39.6
12
0.5
17.0
18.7
1.5
34.4
44.5
13
0.5
13.8
19.4
1.5
15.0
34.6
14
0.5
16.1
25.4
1.5
21.2
39.3
15
0.5
-0.2
11.3
1.5
13.1
29.8
Both the use of a crosslinking agent (examples 1-6) and the use of the two-stage process according to the invention (examples 7-14) lead, when the same amounts are used, to higher strength parameters compared with the polymer solutions (example 15) known from the prior art.
The following preparation examples 16-20 show further possibilities for the preparation of the polymers according to the invention and for carrying out the processes according to the invention. In all cases, polymer solutions which likewise increased the dry strength of paper in a very good manner in pulp or surface applications were obtained.
Example 16
The procedure is as in example 1, but in contrast the starch C (solids content 85.6%) and acrylic acid are used as further monomer in feed 1. The amounts used are as follows:
Starch C
48.5 g
Demineralized water (initially introduced)
995 g
Feed 1): Aqueous solution of the monomers consisting of:
74.7 g of acrylamide
23.35 g of AETAC as 80% strength aqueous solution
3.5 g of acrylic acid
3.0 g of a 1% strength aqueous solution of MBA
100.0 g of demineralized water
10% strength sodium hydroxide solution
22.0 g
A clear, homogeneous polymer solution, having a pH of 5.3, a solids content of 10.3% and a viscosity of 2 390 mPa·s is obtained.
Example 17
1 005 g of demineralized water are initially introduced at room temperature into a 2 1 plane-ground flask having jacket heating and a stirrer, and 49.9 g of starch A (solids content 83.1%) are suspended therein with stirring. The apparatus is then placed under nitrogen. Nitrogen atmosphere and stirring are maintained for the entire further reaction sequence.
The starch suspension is heated to 85° C., the starch glutenizing and forming a slightly turbid solution. After 85° C. have been reached, stirring is continued for 15 min and then 2.0 g of glacial acetic acid and 0.65 g of sodium formaldehyde sulphoxylate dihydrate are added. Thereafter, the following two solutions are metered in uniformly and simultaneously over 90 min at 85° C.:
Feed 1): Aqueous solution of the monomers consisting of:
78.2 g of acrylamide
23:35 g of diallyldimethylammonium chloride as an 80% strength aqueous solution
3.0 g of a 1% strength aqueous solution of MBA
100.0 g of demineralized water
Feed 2): Aqueous solution of the initiator, consisting of:
96.9 g of a 2% strength aqueous solution of ammonium peroxodisulphate
After the end of the metering operations, stirring is continued for 45 min at 85° C., after which 15.0 g of a 2% strength aqueous solution of ammonium peroxodisulphate are added for subsequent activation. Stirring is effected for a further 45 min at 85° C., after which the polymer solution is cooled to room temperature.
The pH is adjusted to 7.1 with about 14 g of 10% strength sodium hydroxide solution, and furthermore 1.4 g of the biocide PREVENTOL® D 2 (Bayer AG) are added. Finally, the polymer solution is filtered through a 100 μm polyamide filter cloth.
A clear, homogeneous polymer solution having a solids content of 10.0% and a viscosity of 10 mPa·s is obtained.
Example 18
The procedure is analogous to example 1, but, instead of MBA, ethylene glycol dimethacrylate is used as a crosslinking agent in feed 1. In contrast to example 1, the following amounts are used:
Starch A (solids content 83.1 %)
49.9
g
Demineralized water (initially introduced)
995
g
1% strength aqueous emulsion of ethylene glycol dimethacrylate
15.0
g
(emulsified by addition of 0.1% of Na dodecylsulphate)
A clear, homogeneous polymer solution having a pH of 7.1, a solids content of 10.2% and a viscosity of 120 mPa·s is obtained.
Example 19
The procedure is analogous to example 7, but a different composition of the polymer is chosen. Specifically, in contrast to example 7, the following amounts are used:
Feed 2:
Acrylamide
73.4
g
Acrylic acid
4.8
g
Demineralized water
80.0
g
10% strength NaOH
about 30
g
A clear, homogeneous polymer solution having a pH of 7.0, a solids content of 9.8% and a viscosity of 25 mPa·s is obtained.
Example 20
1 022 g of demineralized water are initially introduced at room temperature into a 2 1 plane-ground flask having jacket heating and a stirrer, and 49.9 g of starch A (solids content 83.1%) are suspended therein with stirring. The apparatus is then placed under nitrogen. Nitrogen atmosphere and stirring are maintained for the entire further reaction sequence.
The starch suspension is heated to 85° C., the starch glutenizing and forming a slightly turbid solution. After 85° C. have been reached, stirring is continued for 15 min and then 0.5 g of glacial acetic acid, 0.15 g of Rongalit® C (sodium formaldehyde sulphoxylate dihydrate) and 25.6 g of a 65% strength aqueous solution of diallyldimethylammonium chloride are added. For initiation of the 1 st polymerization stage, the following solution is metered in uniformly over 30 min at 85° C.:
Feed 1): Aqueous initiator solution consisting of:
24.2 g of a 2% strength solution of ammonium peroxodisulphate
After completion of feed 1, the 2nd polymerization stage is carried out. For this purpose, the following solutions are metered in uniformly over 90 min at 85° C.:
Feed 2): Aqueous acrylamide solution consisting of:
80.3 g of acrylamide
85.0 g of demineralized water
Feed 3): Aqueous initiator solution consisting of:
72.7 g of a 2% strength solution of ammonium peroxodisuiphate
After the end of the metering operations, stirring is continued for 45 min at 85° C., after which 15.0 g of a 2% strength aqueous solution of ammonium peroxodisulphate are added for subsequent activation. Stirring is effected for a further 45 min at 85° C., after which the polymer solution is cooled to room temperature.
The pH is adjusted to 7.0 with about 6 g of 10% strength sodium hydroxide solution, and furthermore 1.4 g of the biocide PREVENTOL® D 2 (Bayer AG) are added. Finally, the polymer solution is filtered through a 100/lm polyamide filter cloth.
A clear homogeneous polymer solution having a pH of 7.0, a solids content of 10.0% and a viscosity of 10 mPa·s is obtained.
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Embodiments of the present disclosure provide for processes for manufacture of a dry strength paper, methods for imparting dry strength to paper using a cationic starch graft polymer, and the like.
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[0001] This application claims the benefit under 35 U.S.C. 119(e) of U.S. provisional application Ser. No. 61/980,882, filed Apr. 17, 2014.
FIELD OF THE INVENTION
[0002] The present invention relates to a heating assembly arranged to be received in a storage tank, for example an oil storage tank, in which the heating assembly comprises a heating chamber received within an interior of the storage tank and which in turn receives a catalytic heating unit therein.
BACKGROUND
[0003] In oil production, it is common to locate an oil storage tank at an oil well site to produce hydrocarbons from the well directly into the oil storage tank. It is also known to provide a propane burner which directs exhaust into a burner tube extending into the oil storage tank for heating oil in the tank to maintain fluidity and/or prevent freezing of contents within the tank. Heating the oil may also assist in settling sand out of the oil to the bottom of the tank, and assists with fluidity of the oil when subsequently pumping the oil into transport tanker trucks.
[0004] U.S. Pat. No. 7,293,606 by Benoit discloses a heat exchanging apparatus including a gas fuelled flameless catalytic heater. According to one embodiment, an oil storage tank is heated by locating the catalytic heater remotely from the tank and communicating heat exchanger fluid in a loop between the catalytic heater and a heater coil in the tank. Although the heat exchanger fluid can effectively heat the contents of the oil storage tank, the heat exchanger coil in the storage tank can be difficult to maintain as it is subjected to abrasive sands and corrosive fluids within the oil storage tank. Furthermore, considerable heat may be lost in communication between the remotely located catalytic heater and the heater coil in the oil storage tank.
SUMMARY OF THE INVENTION
[0005] According to one aspect of the invention there is provided a heating assembly for use with a catalytic heater unit and an oil storage tank having boundary walls surrounding an interior oil storage chamber, a tank opening in one of the boundary walls, and a tank mounting flange surrounding the tank opening, the heating assembly comprising:
[0006] a heater casing including a plurality of casing walls which surround a heating chamber defined within the casing; and
[0007] a casing mounting flange joined to the casing walls;
[0008] the casing mounting flange being mountable in sealing engagement relative to the tank mounting flange such that the casing protrudes into the interior oil storage chamber of the oil storage tank;
[0009] the casing mounting flange and the casing walls of the heater casing collectively forming a barrier arranged to fully enclose the tank opening when the casing mounting flange is mounted in sealing engagement relative to the tank mounting flange; and
[0010] the heating chamber being suitable sized and configured to operably receive the catalytic heater therein.
[0011] The heater casing received within the oil storage compartment of the oil storage tank allows heat to be transferred directly from the catalytic heater unit to the casing, which in turn communicates the heat directly to the surrounding oil in the storage tank. The casing occupies a larger volume than a typical heat exchanger coil for more efficient transfer of heat to the surrounding oil in the storage tank. Furthermore, the heater casing can be much more robust in construction than a typical heat exchanger coil such that abrasive sands and corrosive fluids are much less of concern with regard to maintenance of the heater unit.
[0012] The casing mounting flange is located at one end of the casing such that the casing mounting flange is joined to the casing walls such that the casing is arranged to be fully received within the interior oil storage chamber of the oil storage tank.
[0013] Preferably a main opening is provided at one end of the casing which is suitably sized to receive the catalytic heating unit therethrough. The casing mounting flange may be located at one end of the casing such that the main opening lies in a plane of the casing mounting flange.
[0014] Preferably a door is supported on the casing so as to be operable between a closed position spanning the main opening and an open position in which the main opening is sufficiently unobstructed by the door to receive the catalytic heating unit therethrough. The door is preferably heat insulated.
[0015] There may further be provided a carriage member arranged to support the heater unit thereon and a slide assembly supporting the carriage member within the casing so as to be longitudinally slidable between a loading position in proximity to the main opening and a working position spaced inwardly into the heating chamber of the casing from the main opening relative to the loading position.
[0016] The heating chamber of the casing is preferably suitably sized to receive the catalytic heater unit therein such that the casing walls are spaced apart from the catalytic heater unit on all sides thereof.
[0017] More particularly, the heating chamber of the casing is preferably suitably sized such that the catalytic heater unit is arranged to be received therein at a location corresponding to the catalytic heater unit being fully received within the interior oil storage chamber of the oil storage tank at a location spaced inwardly from the boundary walls of the oil storage tank.
[0018] The casing preferably includes a combustion air inlet and an exhaust outlet formed in the casing so as to be arranged to communicate from the heating chamber to an exterior of the storage tank.
[0019] Preferably the combustion air inlet and the exhaust outlet are formed in a common one of the casing walls at an exterior end of the casing in which the combustion air inlet is located in proximity to a bottom end of the casing and the exhaust outlet is located in proximity to a top end of the casing. There may further me provided an exhaust collection hood in communication with the exhaust outlet which is supported within the casing so as to be arranged to receive exhaust from the heater unit received therebelow.
[0020] There may further be provided a fuel supply line arranged to communicate between an external fuel supply and the catalytic heating unit within the heating chamber of the casing in which at least a portion of the fuel supply line within the heating chamber of the casing comprises a flexible line.
[0021] According to a second aspect of the present invention there is provided an oil storage tank comprising:
[0022] boundary walls surrounding an interior oil storage chamber;
[0023] a tank opening in one of the boundary walls;
[0024] a tank mounting flange surrounding the tank opening;
[0025] a heating assembly, as described above, in which the casing mounting flange is mounted in sealing engagement relative to the tank mounting flange such that the heater casing protrudes into the interior oil storage chamber of the oil storage tank, and the casing mounting flange and the casing walls of the heater casing collectively form a barrier which fully encloses the tank opening; and
[0026] a catalytic heater unit operably received within the heating chamber of the casing.
[0027] Preferably the casing mounting flange is located at one end of the casing such that the casing is fully received within the interior oil storage chamber of the oil storage tank.
[0028] Preferably the catalytic heater unit is also located within the casing so as to be fully received within the interior oil storage chamber of the oil storage tank at a location spaced inwardly from the boundary walls of the oil storage tank.
[0029] One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a perspective view of the heating assembly;
[0031] FIG. 2 is a sectional view of the heating assembly along the line 2 - 2 in FIG. 1 ;
[0032] FIG. 3 is a sectional view of the heating assembly along the line 3 - 3 of FIG. 2 ;
[0033] FIG. 4 is a perspective view of the heating assembly shown supported on a horizontal tank; and
[0034] FIG. 5 is a perspective view of the heating assembly shown supported on an upright tank.
[0035] In the drawings like characters of reference indicate corresponding parts in the different figures.
DETAILED DESCRIPTION
[0036] Referring to the accompanying figures, there is illustrated a heating assembly generally indicated by reference numeral 10 . The assembly 10 is suited for heating a liquid storage tank 12 having tank boundary walls 14 surrounding the hollow interior which defines a main liquid storage portion for storing liquid, for example oil therein. The heating assembly 10 is used with a hydrocarbon fuelled flameless catalytic heater unit 16 .
[0037] The heater unit 16 in a conventional catalytic heater unit, for example of the type available under the trademark name Catadyne. A typical heater unit relies on a flameless combustion or oxidation of a gaseous hydrocarbon fuel, for example natural gas or propane fed by a fuel supply line, in order to produce heat. The heater unit typically includes a respective housing which contains a catalyst pad having a catalyst carried on a substrate to provide a catalyst bed upon which the fuel is combusted. The combustion is an exothermic oxidation reaction between the hydrocarbon fuel and oxygen, assisted by the presence of the catalyst, to produce water vapor, carbon dioxide and radiant heat in the form of infrared energy. An electrical heating element may be included, within the housing of the heater unit to preheat the catalyst pad initially during start-up of the heater unit.
[0038] The heating assembly 10 generally includes a heater casing 20 which is elongate in a longitudinal direction between an external and 22 arranged to be supported in proximity to a boundary wall of the storage tank, and an interior end 24 arranged to be positioned within the interior storage chamber of the storage tank 12 at a location spaced inwardly from the corresponding boundary wall.
[0039] More particularly, the casing 20 comprises a top wall 26 , a bottom wall 28 , and two laterally opposed side walls 30 which collectively surround the heating chamber while spanning in the longitudinal direction between the opposing exterior and interior ends. A first end wall 32 spans the exterior end and a corresponding second end wall 34 spans the interior end to fully enclose the interior chamber.
[0040] The first end wall 32 protrudes outwardly beyond the corresponding casing walls 26 , 28 and 30 on all sides to define a casing mounting flange 36 as the peripheral portion of the first end wall protruding beyond the casing walls. The casing mounting flange 36 thus extends about the full circumference of the casing while being oriented in a plane which is perpendicular to the longitudinal direction thereof.
[0041] The storage tank 12 is prepared to receive the casing of the heating assembly therein by providing the tank with a tank opening 38 in an upright one of the boundary walls. The tank opening is suitably sized to receive the casing inserted into the storage tank therethrough. A mounting collar 40 is mounted about the periphery of the tank opening in which the collar projects perpendicularly outward from the corresponding boundary wall about the tank opening.
[0042] At the exterior end of the collar 40 , a tank mounting flange 42 is provided which extends radially outward from the outer end of the collar 40 about the full circumference thereof so that the tank mounting flange is generally annular in shape and is oriented parallel to the corresponding boundary wall at a location spaced longitudinally outward in the axial direction of the weld collar from the boundary wall. The tank mounting flange 42 is substantially identical in size and configuration to the casing mounting flange 36 in which both mounting flanges include corresponding fastener holes which are aligned with one another in a mounted position of the casing on the storage tank.
[0043] A suitable annular gasket 44 is sandwiched between the mounting flanges with corresponding bolts 46 extending in the axial direction through co-operating apertures in both mounting flanges to clamp the mounting flanges together with the gasket therebetween. The collar 40 provides sufficient space between the tank mounting flange 42 and the boundary wall to provide access to the fasteners from behind.
[0044] In a mounted position, the casing 20 is fully received within the interior of the tank so as to be substantially fully received within the perimeter of the storage tank as defined by the boundary walls. The casing walls, and in particular the top wall 26 , the bottom wall 28 , the two side walls 30 and the second end wall 34 are joined to one another and the casing mounting flange 36 so as to collectively form a barrier which fully spans and encloses the tank opening 38 in the mounted position of the casing. The casing protrudes into the storage tank by a sufficient distance such that a catalytic heater unit 16 supported within the heating chamber of the casing can be positioned at a location spaced inwardly from the corresponding boundary wall of the storage tank.
[0045] The casing 20 further includes a main opening 50 within the first end wall 32 for communicating to the exterior from the inner heating chamber of the casing. The main opening is suitably sized to permit the catalytic heater unit to be received therethrough. A door 52 is provided which is coupled by hinges to the exterior side of the first end wall so that the door can be pivotally operated between a closed position fully spanning and enclosing the main opening 50 , and an open position in which the main opening 50 is sufficiently unobstructed by the door 52 to permit the heater unit to be received through the main opening.
[0046] Combustion air is provided to the catalytic heater unit through a combustion air inlet 54 in the form of an opening in the first end wall in proximity to the bottom of the casing, below the main opening 50 . The air inlet is sufficiently sized to allow fresh air for combustion to enter therethrough into the interior chamber. A grate or other suitable structure may be provided to partially restrict access through the opening of the air inlet 54 . In further arrangements the air inlet may be provided in the door 52 in proximity to the bottom end thereof.
[0047] An exhaust collection hood 56 is mounted within the interior of the heating chamber in proximity to the top wall so as to be located directly above the heater unit in the working position thereof. The hood 56 comprises an enclosed duct which is open at the bottom side thereof so that hot exhaust gases will passively rise from the catalytic heater unit up through the open bottom end of the collection hood thereabove. An exhaust opening 58 is provided in the first end wall in proximity to the top end of the casing so as to be located above the main opening 50 . An exhaust pipe 60 communicates from the collection hood 56 through the exhaust opening 58 such that exhaust collected within the hood can be subsequently passively directed through the exhaust pipe and to the exterior through the exhaust opening 58 .
[0048] A fuel source is mounted externally of the casing and storage tank for supplying fuel, for example propane or natural gas, to the catalytic heater unit through a fuel line 62 connected therebetween. The fuel line 62 communicates through a corresponding fuel opening in the first end wall in proximity to the combustion air inlet, below the main opening 50 . The fuel line 62 includes a flexible portion 64 which communicates between the first end wall and the heater unit to permit displacement of the heater unit relative to the casing during initial mounting of the unit in the casing and during subsequent removal and remounting for maintenance and the like while the fuel line remains connected to the heater unit.
[0049] The heater unit is supported within the casing on a carriage member 66 supported within the bottom end of the heating chamber of the casing. A slide assembly comprising longitudinally extending rails 68 support the carriage member and the catalytic heater unit thereon such that the carriage and heater unit are longitudinally slidable along the rails 68 between a working position supported fully within the interior of the heating chamber at a location spaced inwardly from the boundary wall of the storage tank to permit the door to be secured in the closed position, and a loading position in which the carriage and heater unit supported thereon can be slidably displaced outward to project partially or fully through the main opening 50 when the doors opened.
[0050] In the mounted position, the heater unit is typically operated steadily at a low level to provide sufficient heat to prevent freezing of the contents of the storage tank. The controller of the catalytic heater unit may include a thermostat which cycles operation of the heater unit simply to maintain air within the enclosed heating chamber receiving the heater unit therein within a prescribed temperature range, or more particularly above a lower limit and below an upper limit of the thermostat.
[0051] The exterior of the boundary wall of the storage tank 12 and the exterior of the collar 40 of the storage tank are preferably coated with an insulating material, for example spray foam, to assist in maintaining heat within the storage tank. In addition, the door 52 and the first end wall of the heating assembly may be further insulated with a heat insulating material such as spray foam and the like to minimize heat loss through the exterior end of the casing.
[0052] The casing walls including the top wall, the bottom wall, the two side walls, and the second end wall remain uninsulated to permit heat to be readily transferred thereacross from the catalytic heater unit to the surrounding fluid in the storage tank. The heater unit primarily transmits heat in the form of infrared radiant energy which radiates from the heater unit to the casing walls of the casing which then in turn transfers heat to the surrounding fluid by conduction and convection.
[0053] Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.
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In an oil storage tank having an interior oil storage chamber and a tank opening in one of the boundary walls, a heating assembly is supported to extend into the interior oil storage chamber from the tank opening. The assembly includes a casing of walls surrounding with a casing mounting flange mountable in sealing engagement relative to a tank mounting flange about the full perimeter of the tank opening such that the casing protrudes into the interior oil storage chamber of the oil storage tank. The heating chamber is suitable sized and configured to operably receive a catalytic heater therein. The heating chamber further accommodates entry of combustion air and combustion fuel into the heating chamber and exhaust of emissions therefrom.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the structure of an angle portion that makes up an insertion portion of an endoscope used for medical use, etc.
2. Description of the Related Art
Generally, with an endoscope for medical use, etc., an insertion portion, for insertion into a body cavity, etc., is connected to a body control portion, and a universal cable, which is detachably connected at least to a light source device, is lead out to the body control portion. The insertion portion comprises, in the order from the side connected to the body control portion, a flexible portion, an angle portion, and a distal end hard portion, and the angle portion, which is connected to the front end of the flexible portion, which can be bent in an arbitrary direction in accordance with an insertion path of the insertion portion, is a portion that can be operated to become bent by an angle control section disposed at the body control portion. An endoscopic observation mechanism, comprising an illumination portion and an observation portion, is mounted to the distal end hard portion, and by performing a bending operation of the angle portion, the direction of the distal end hard portion can be controlled to thereby orient the distal end hard portion towards an insertion path or change the endoscopic observation field.
In regard to the structure of the angle portion, an angle portion structure, equipped with a predetermined number of angle rings, is formed by pivotally joining the angle rings to each other in the front/rear direction successively by means of pivoting joint pins. The outer periphery of the angle portion structure is covered with a net, and this net is furthermore covered with an outer sheath layer formed of a flexible member. The interior of the angle portion structure is thus a passage of a cylindrical shape, and various members are inserted into this passage. Members inserted into this passage include a light guide that transmits illumination light and a signal cable that extends from a solid-state image pickup element disposed at the observation portion (an image guide in the case of an optical endoscope), and an operative instrument insertion channel, an air/water feed tube, etc., are also inserted into this passage.
Here, at the rigid front end part, the front end of the operative instrument insertion channel opens to a position near the observation portion. When an affected part, etc., is found while observing the interior of a body cavity by the endoscopic observation mechanism, the operative instrument insertion channel is used to perform a curative procedure, sampling of tissue, or injection of a medical solution, etc., and a forceps or other operative instrument is inserted into the channel with the insertion portion being inserted inside the body cavity. The operative instrument insertion channel extends into the insertion portion from the body control portion and the portions from the body control portion to the portion connected to the distal end hard portion are formed of a flexible tube that can be bent in arbitrary directions.
In order to enable bending of the angle portion, the angle rings in the front/rear direction are connected in a mutually inclinable manner, and pivoting joint portions are pivotally joined at two locations along the circumference of each angle ring that are separated by 180°. With each angle ring, notched portions are formed obliquely in directions of 90° from each pivoting joint portion, and the angle of inclination of angle rings in the front/rear direction is controlled by the angle of the notched portions. The curvature of bending of the angle portion is thus determined by the length dimension of each angle ring and the inclination angle, that is, the notch width of each notched portion. When the angle rings are pivotally joined at the left and right sides, the angle portion can bend as a whole in the upward and downward directions and when pivotal joining at the left and right sides and at the front and rear are repeated in that order, the angle portion can bend as a whole in the four directions of leftward, rightward, upward, and downward.
In order to make the angle portion become bent by remote operation, two to four angle operating wires are extended from a take-up reel that makes up an angle operating device provided in the body control portion, and these angle operating wires are extended in a manner enabling pushing and pulling operations while being positioned in the circumferential direction by wire guides inside the angle portion. When, for example, the angle portion is to be bent in the upward or downward direction, one of the pair of angle operating wires that are positioned at upper and lower positions is pulled and the other is operated so as to be drawn out. The angle portion is provided for performing the operation of directing the distal end hard portion to a desired direction, and in order to enable the change of direction of the endoscopic observation field at the distal end hard portion from the frontward to the rearward direction, the angle of curvature in at least one direction should be no less than 180° and preferably no less than 200°. The length of the angle portion and the shapes of the angle rings, which form the structural body of the angle portion, are set with the maximum angle of curvature as a basis.
The angle portion is operated to become bent inside a narrow body cavity and thus the locus of the movement of the angle portion in a bending operation is preferably made as compact as possible. Meanwhile, since an operative instrument may be inserted into the operative instrument insertion channel even with the angle portion being bent, the radius of curvature in the maximum bent state is preferably as large as possible in order to enable smooth insertion of the operative instrument.
Here, an arrangement, wherein the length dimensions of the angle rings and the positions of the wire guides, provided for positioning the angle operating wires in the circumferential direction, are varied in the axial line direction to control the bending shape of the angle portion, is disclosed, for example, in JP-A-3-218723.
With the above-mentioned related-art, by making the angle rings decrease continuously in length towards the front end side of the angle portion, that is, towards the side of connection to the distal end hard portion, the radius of curvature of bending of the angle portion is made small, and as a result of the angle portion thus being made compact in movement and the locus of movement of the rigid front end part, in the process of performing a bending operation of the angle portion inside a narrow body cavity, being made compact, the rigid front end part is prevented from becoming pressed strongly against the inner walls of the body cavity during this operation, thereby alleviating the pain that is inflicted on a subject and improving the operability of the angle portion.
However, it is required that the ease of insertion of an operative instrument into the operative instrument insertion channel be good even when the angle portion is in a bent state. Though the operative instrument that is inserted into the operative instrument insertion channel may be a flexible member, such as a tube, the operative instrument may instead be a forceps or other considerably rigid object, which has forceps claws and a forceps claw opening/closing mechanism disposed at the front end and thus with which a portion of some length in the axial line direction is a rigid portion. When the angle portion is bent, the operative instrument insertion channel, which is inserted in the interior thereof also becomes bent at substantially the same curvature as the angle portion, and in the maximally bent state, the operative instrument insertion channel will also become bent sharply. Insertion of a forceps or other operative instrument of poor insertion condition in a passage that is sharply bent in this manner accompanies high resistance against insertion and not only is the operability poor but the inner surface of the operative instrument insertion channel may become pressed by the front end portion of the operative instrument and the flexible tube that makes up the operative instrument insertion channel may become deformed or damaged, etc.
SUMMARY OF THE INVENTION
This invention has been made in view of the above points, and an object thereof is to provide an angle portion that can be bent to the required angle of curvature while making the locus of movement of the angle portion during a bending operation as compact as possible and yet making the radius of curvature during bending as large as possible.
In order to achieve the above object, the present invention provides in an endoscope angle portion, having an angle portion structure, comprising a predetermined number of angle ring units, each angle ring unit having pivoting joint portions extending from both ends thereof and having a shape that is notched obliquely in directions away from the pivoting joint portions, and wherein the angle portion structure is formed by pivotally joining the angle ring units in the front/rear direction, an endoscope angle portion characterized in that with angle ring units at a base end side and angle ring units at a front end side among the angle ring units forming the angle portion structure, the angle ring units at the base end side are made larger in length dimension and smaller in notch width of the notched portion.
In other words, according to the invention, there is provided an endoscope angle portion comprising an angle portion structure including angle ring units each of which comprises pivoting joint portions extending from its both ends and has a shape that is notched obliquely in directions away from the pivoting joint portions, and wherein adjacent ones of the angle ring units is pivotally joined to form the angle portion structure, wherein a first angle ring unit of the angle ring units has a larger length dimension than that of a second angle ring unit of the angle ring units, and the first angle ring unit has a smaller notch width of a notched portion than that of the second angle ring unit, the first angle ring unit being nearer a base end of the endoscope angle portion than the second angle ring unit.
Each angle ring is arranged from a member of cylindrical shape that has extending portions formed at the left and right sides or pairs of extending portions formed at the left/right sides and upper/lower sides, respectively, as pivoting joint portions, and angle rings in the front/rear direction are connected by joining and stopping the pivoting joint portions by means of pivoting joint pins. When respective pairs of the pivoting joint portions at the left/right sides are pivotally joined to each other, the angle portion can be bent in upward and downward directions. When the pivoting joint portions at the upper/lower sides and left/right sides are joined in an alternating manner, the angle portion can be bent in the four directions of upward, downward, leftward, and rightward. In the case where such bending in four directions is enabled, each pair of angle rings that are pivotally joined at the upper/lower sides function as a single, integral unit during bending in the upward and downward directions. In the case of an arrangement enabling bending in two directions, each angle ring unit is a single angle ring, and in the case of an arrangement enabling bending in four directions, each angle ring unit is a set of two angle rings.
Generally, in the case of an arrangement enabling bending in four directions, the maximum curvature of bending is enabled for bending in the upward direction. As the angle ring unit in this case, a pair of front and rear angle rings, which are pivotally joined so as to enable bending in the left and right directions, make up a single angle ring unit. In other words, each of the angle ring units comprises a pair of angle rings so as to bend to a left direction and right direction of the endoscope angle portion, and the angle ring units are provided in an axial line direction of the endoscope angle portion so that the angle portion structure can bend upward and downward.
The length dimension of an angle ring unit is the interval between two pivoting joint portions, positioned at one side and the other side, respectively, and extending in the same direction in the circumferential direction. To be more precise, the length dimension is the interval between the central positions of pivoting joint pins that are fixed to the pivoting joint portions. Portions of each angle ring in the direction of approximately 90° from each pivoting joint portion are inclined obliquely and these inclined portions are the notched portions, and the width dimension of each notched portion is determined by the angle of inclination at the notched portion. The length dimension and the notch width of each angle ring unit are set as described above, and in the axial line direction of the angle portion, the shapes of the angle ring units are varied in a continuous manner or in a step-like manner. In the case of continuous variation, a plurality of types of angle rings that differ in dimensions are used. With an arrangement in which the shapes are varied in a step-like manner, the number of types of angle rings used can be made low. It is thus preferable to vary the angle ring units in a step-like manner and most preferably, the angle ring units are varied in approximately two or three steps. In this case, by making the length dimension of each angle ring unit and the notch width dimension of each notched portion change at the front and rear of a boundary, corresponding to positions of an arc spanning approximately ¼th of a circle formed at the base end side when the angle portion structure is bent to the maximum curvature of bending, the locus of movement of the distal end hard portion during bending operation of the angle portion can be made as compact as possible and yet the radius of curvature during bending can be made large. In other words, third angle ring units of the angle ring units form an arc spanning approximately ¼th of a circle in the state in which the angle portion structure is bent to the maximum curvature of bending, the third angle ring units being nearest the base end of the endoscope angle portion, and an angle ring unit adjacent to the distal one of the third angle ring units has a different length dimension from that of the distal one of the third angle ring units, and has a different notch width of a notched portion from that of the distal one of the third angle ring units.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall arrangement diagram of an endoscope equipped with an angle portion of the present invention;
FIG. 2 is a sectional view of the angle portion of FIG. 1 ;
FIG. 3 is an action explanation diagram of the action states of an insertion portion;
FIG. 4 is a front view of an angle ring unit;
FIG. 5 is a front view of two types of angle rings used in angle ring units; and
FIGS. 6A and 6B are arrangement explanation diagrams of a state in which an angle portion structure is extended straightly and a state in which the angle portion structure is bent by 90°.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention shall now be described with reference to the drawings. FIG. 1 shows the overall arrangement of an endoscope and FIG. 2 shows a cross section of a front end section of an insertion portion.
Firstly, in FIG. 1 , 1 is a body control portion, 2 is an insertion portion, and 3 is a universal cable. The body control portion 1 is held by one hand and operated by an operating surgeon or other endoscope operator, and the insertion portion 2 is inserted inside a body cavity. The universal cable 3 is equipped with a light source connector, the other end of which is detachably connected to a light source device. A connector for connection to a processor, which is provided integral to or separate from the light source device, is also equipped in the case of an electronic endoscope. The arrangement of the end section of the universal cable 3 is well known and illustration and description thereof shall be omitted.
The insertion portion 2 has a section of predetermined length from the portion connected to the body control portion 1 arranged as a flexible portion 2 a , which can be bent in an arbitrary direction in accordance with the insertion path of the insertion portion. An angle portion 2 b is connected to the front end of the flexible portion 2 a , and a distal end hard portion 2 c is connected to the front end of the angle portion 2 b . As shown in FIG. 2 , an endoscopic observation mechanism 4 , comprising an illumination portion and an observation portion, is provided on the front end face (or front end side face) of the distal end hard portion 2 c , and an operative instrument insertion channel 5 opens at a position near the observation portion. The angle portion 2 b is for controlling the direction of insertion of the distal end hard portion 2 c and changing the endoscopic observation field of the endoscopic observation mechanism 4 . In order to provide a wide view field from the front to the rear of the inserted instrument 2 as the endoscopic observation field, the angle portion 2 b can be bent to an angle of curvature of no less than 180° and preferably no less than 200°.
The arrangement of the angle portion 2 b is shown in FIG. 2 . The angle portion 2 b has an angle portion structure 10 , the interior of which forms a circular passage, and this angle portion structure 10 is covered by a net 11 . The net 11 is furthermore covered by an outer sheath 12 , formed of an elastic member. The angle portion structure 10 is thus the structural body of the angle portion 2 b , and although omitted from illustration, the various members indicated in the description of the related-art are inserted into its internal passage. The angle portion structure 10 has a high strength in the direction of compression, and angle rings 13 are thus formed of metal.
The angle portion structure 10 is formed by pivotally joining the angle rings 13 successively, and at the respective ends thereof are disposed a base end connection ring 13 B, which is connected to the flexible portion 2 a , and a front end connection ring 13 F, which is connected to the distal end hard portion 2 c . Each angle ring 13 is an annular member having pivoting joint portions 13 a and 13 b provided at the respective sides, and these pivoting joint portions 13 a and 13 b are formed as flat portions. The pivoting joint portions 13 a at one end side are provided as a pair in a positional relationship of 180° with respect to each other, and the pivoting joint portions 13 b at the other end side are provided as a pair in a positional relationship of 90° with respect to the pivoting joint portions 13 a at the one end side. These pivoting joint portions 13 a and 13 b , respectively, have pin insertion holes formed therein, and by joining the respective pivoting joint portions 13 a or joining the respective pivoting joint portions 13 b of angle rings 13 in the front/rear direction and stopping by means of pivoting joint pins 14 , the angle rings 13 in the front/rear direction are joined in a manner enabling rotation relative to each other about the axes of pivoting joint pins 14 . For example, at a portion at which the left and right pivoting joint portions 13 a of angle rings 13 in the front/rear direction are pivotally joined to each other, the angle rings 13 in the front/rear direction are rotatable in the upward and downward directions. Meanwhile, a portion, at which the upper and lower pivoting joint portions 13 b are pivotally joined to each other, is enabled to rotate in the leftward and rightward directions.
Among the base end and front end connection rings 13 B and 13 F at the respective ends of the angle portion structure 10 , the base end connection ring 13 B has pivoting joint portions for connection to an angle ring 13 positioned at the front thereof, is not provided with pivoting joint portions at the base end side, and is connected and fixed by soldering or other means to a connection ring 15 to the flexible portion 2 . The front end connection ring 13 F is equipped with pivoting joint portions for connection to an angle ring 13 to the rear thereof but is not provided with pivoting joint portions at the front end side thereof. This front end connection ring 13 F is fitted into and fixed by a set screw or other means to a base end portion of the distal end hard portion 2 c.
The angle portion 2 b is arranged so that it can be bent by remote operation by an angle operating device 6 , disposed at the body control portion 1 . A wire guide hole 14 a is thus bored in each pivoting joint pin 14 , operating wires 16 are inserted through these wire guide holes 14 a , and the front end portion of each operating wire 16 is fixed to the front end connection ring 13 F. The guides for operating wires 16 may instead be arranged from cut-and-constricted portions provided on the angle rings 13 .
FIG. 3 shows a state in which the insertion portion 2 of the endoscope with the above-described arrangement is inserted inside a body cavity. Inside this body cavity, the distal end hard portion 2 c can be changed in direction to thereby the direction of the endoscopic observation field from the front side of the insertion portion 2 to the rear side. For this purpose, the angle portion 2 b is operated to bend, and in this process of bending the angle portion 2 b , the orientation state, which is attained when the angle portion 2 b is bent, from the state of being directed straightly forward as indicated by the solid lines, to a right angle with respect to the straight state, is indicated as b in the figure, and the orientation state, at which the maximum angle of curvature is attained, is indicated as c in the figure.
The upright height H of the angle portion 2 b in the orientation state b must be made low. When this height H becomes high, the distal end hard portion 2 c becomes pressed against the inner wall of the body cavity in the process of changing direction. As a result, the resistance during the bending operation becomes large and severe pain is inflicted on the subject as well. Furthermore, if the height H becomes significantly high, the inner walls of the body cavity may become damaged. The operative instrument insertion channel 5 is inserted through the interior of the angle portion 2 b , and since this operative instrument insertion channel 5 becomes bent at substantially the same curvature as the curvature of bending of the angle portion 2 b , if the radius of curvature of the angle portion 2 b is small, the operative instrument insertion channel 5 will become bent sharply accordingly. The operation of inserting an operative instrument inside the operative instrument insertion channel 5 is thus made difficult. In particular, in the case of a forceps, etc., that has a hard portion of predetermined length at the front end portion, the resistance against insertion inside the operative instrument insertion channel 5 becomes extremely large and in extreme cases, the operative instrument may become locked in the middle. Furthermore, in order to realize a large variation of the endoscopic observation field, the angle portion 2 b is enabled to become bent by no less than 180° in at least one direction in the maximally bent state.
When with an arrangement wherein the angle portion 2 b is enabled to become bent in the four directions of upward, downward, leftward, and rightward, the same angle of curvature is not enabled for all of these directions but arrangements are made so that the angle of curvature will be maximized for one of the directions, specifically, the upward direction, and when the observation field of the endoscopic observation mechanism is to be directed towards the rear, the angle portion 2 b is generally bent upwards, that is, in the direction shown in FIG. 3 . Arrangements are thus made so that in the state in which the angle portion 2 b is erected to an angle of 90° from the axial line of the insertion portion in the upwardly bending operation, the upright height dimension H from the axial central line L of the insertion portion will be restrained to the minimum and yet the radius of curvature R at the state of the maximum angle of curvature is made as large as possible.
When in the case where the angle portion 2 b is enabled to be bent in the four directions of upward, downward, leftward, and rightward, the angle portion 2 b is bent upward, each set of two angle rings 13 , among the angle rings 13 in the front/rear direction, with which the pivoting joint parts 13 b are pivotally joined, become practically integrated in the process of bending in the upward/downward direction. Such an angle ring unit is indicated by the symbol 13 U in FIG. 4 . Though in the case of an arrangement wherein bending in the two directions of upward and downward is enabled, each angle ring unit 13 U is arranged from a single angle ring, in the case of an arrangement enabling bending in the four directions of upward, downward, leftward, and rightward, each angle ring unit 13 U is arranged from two angle rings 13 in the front/rear directions.
Here, where S is the length dimension of the angle ring unit 13 U in the axial line direction. This length dimension S is the interval from the center of the pivoting joint pin 14 , mounted to one of the pivoting joint portions 13 a , and the center of the pivoting joint pin 14 , mounted to the other pivoting joint portion 13 a . Also, where the interval in the axial line direction of the notched portion of the angle ring unit 13 U is the notch width T. Each angle ring unit 13 U is then arranged as described below in order to restrain the height dimension H, when the angle portion 2 b is directed upward and bent to a state of an angle of 90° with respect to the axial line of the insertion portion 2 , to the minimum and yet make large the radius of curvature R when the maximum angle of curvature is attained.
Firstly, two types of angle rings that differ in the length dimension and the notch width dimension are used. Each angle ring unit 13 U is arranged from two angle rings, and as shown in FIG. 5 , for one angle ring 13 P of the two types of angle rings, the length dimension, specifically, the interval, from the center of the pin insertion hole of the pivoting joint portion 13 a to the center of the pin insertion hole of the pivoting joint portion 13 a , is indicated as s 1 and the width of the notched portion in the phase direction of 90° from the pivoting joint portion is indicated as t 1 , and for the other angle ring 13 Q, the length dimension is indicated as s 2 and the notch width is indicated as t 2 . Here, the dimensional relationships s 1 >s 2 and t 1 <t 2 are made to hold.
The external appearance of the upper half of the angle portion structure 10 is shown in FIG. 6A . As is clear from this figure, in regard to the angle ring units, the structure is arranged from angle ring units 13 UX, in each of which two angle rings 13 P are connected, an angle ring unit 13 UY, in which an angle ring 13 P and an angle ring 13 Q are connected, and angle ring units 13 UZ, in each of which two angle rings 13 Q are connected. The length dimension S of each angle ring unit 13 UX is 2s 1 and thus the largest, the length dimension S of the angle ring unit 13 UY is (s 1 +s 2 ) and is thus of intermediate magnitude, and the length dimension S of each angle ring unit 13 UZ is 2s 2 and thus the smallest. From the base end connection ring 13 B, a predetermined number of angle ring units 13 UX (corresponding to third angle units) are connected successively, and from the front end connection ring 13 F, a predetermined number of angle ring units 13 UZ are connected successively. One angle ring unit 13 UY is disposed in the middle. In this embodiment, the angle ring unit 13 UY corresponds to an angle unit adjacent to the distal one 13 UX′ of the angle ring units 13 UX (third angle units).
Due to the above, the total notch width is 2t 1 and is the smallest at each connection portion at which the angle ring units 13 UX are connected to each other and at the portion of connection of 13 UX with 13 UY, the total notch width is t 1 +t 2 and thus of intermediate value at the portion of connection of the angle ring units 13 UY and 13 UZ, and the total notch width is 2t 2 and is the largest at each of the portions of connection of the angle ring units 13 UZ with each other.
When the angle portion 2 b is bent by applying tension to an operating wire 16 , the angle portion 2 b does not begin to bend as a whole but becomes bent successively from the base end side. That is, the wall surfaces that make up the notched portions between the base end connection ring 13 B and the adjacent angle ring unit 13 UX contact each other, then the wall surfaces making up the notched portions between this angle ring unit 13 UX and the angle ring unit 13 UX positioned in front contact each other, and bending is performed successively towards the front end side. Thus, in the middle of the bending operation of angle portion 2 b , there exists a state wherein although the base end side is bent, the front end side is straight as shown in FIG. 6 B. That is, when the angle portion 2 b is operated to become bent, first its base end side is made upright and the front end side becomes bent and the state of maximum curvature is reached via the state of FIG. 6B .
In the state in which the angle portion 2 b is bent at an angle of 90° as shown in FIG. 6B and thus in the state of maximum curvature, the radius of curvature of the angle ring units 13 UX becomes R, and of the total length of the angle portion 2 b , the portion, corresponding to arc angle positions making up ¼th of the circle of radius of curvature R, is arranged from the angle ring units 13 UX. The radius of curvature at the portion of the starting end of bending can thus be made large. If the angle portion 2 b is arranged from the angle ring units 13 UX over its entire length, the height H will become extremely high. However, since a single angle ring unit 13 UY, which is shorter in length than angle ring unit 13 UX, and a plurality of angle ring units 13 UY, which are even shorter, are disposed at the front end side of the angle ring units 13 UX, the height dimension H when the angle portion 2 b is made upright to an angle of 90° from the axial line of the insertion portion 2 can be made correspondingly lower. In the locus of movement of the distal end hard portion 2 c in the process of a bending operation of the angle portion 2 b , the widest space becomes necessary when the angle portion 2 b is made upright to 90° with respect to the axial line of the insertion portion. Here by restraining this height H to the minimum, the locus of movement is made compact, the angle portion 2 b is made good in operability, and pain inflicted on the subject can be lightened.
When the angle portion 2 b is put in the maximally bent state, the portion made up of the angle ring units 13 UZ, which are positioned along the extension of the portion made up of the angle ring units 13 UX, becomes small in radius of curvature than the portion made up of the angle ring units 13 UX. However, since the angle ring unit 13 UY exists in between, the transition of the radius of curvature is relaxed, and since bending occurs at a stage prior to this transition portion, the transition of the radius of curvature corresponds to the difference in the radii of curvature of the angle ring units 13 UX and the angle ring units 13 UZ. The degree of change of bending will thus be small. Thus, when in the state in which the angle portion 2 b is maximally bent, an operative instrument is inserted inside the operative instrument insertion channel 5 , since the operative instrument will be put in a gradually bent state initially and will become bent further by just the difference in the radii of curvature at the portion of transition of the radius of curvature, smooth insertion operability is secured. On the other hand, if the angle ring units 13 UZ are connected across the entire length of the angle portion 2 b , the radius of curvature of the angle portion 2 b as a whole will be small and the insertability of the operative instrument will be poor.
Even if the length dimensions of the angle ring units are varied in a continuous manner or the width dimensions of the notched portions are varied in a continuous manner, the height dimension H will become higher or the radius of curvature R will become smaller, or the height dimension H will become higher and the radius of curvature R will become smaller in comparison to the above-described arrangement of the present invention.
By appropriately setting the numbers and shapes of the angle ring units 13 UX and the angle ring units 13 UZ, the required angle of curvature can be realized.
By the above arrangement, the angle portion can be enabled to be bent compactly without placing restrictions on the angle of curvature of the angle portion, the curvature of bending can be made large to enable smooth angle operation inside a narrow body cavity, the pain inflicted on a subject can be lowered, and the operability of insertion of operative instruments can be improved.
The entire disclosure of each and every foreign patent application from which the benefit of foreign priority has been claimed in the present application is incorporated herein by reference, as if fully set forth.
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An endoscope angle portion comprises an angle portion structure. The angle portion structure includes angle ring units each of which comprises pivoting joint portions extending from its both ends and has a shape that is notched obliquely in directions away from the pivoting joint portions, and wherein adjacent ones of the angle ring units is pivotally joined to form the angle portion structure, wherein a first angle ring unit of the angle ring units has a larger length dimension than that of a second angle ring unit of the angle ring units, and the first angle ring unit has a smaller notch width of a notched portion than that of the second angle ring unit, the first angle ring unit being nearer a base end of the endoscope angle portion than the second angle ring unit.
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THE INVENTION
This invention relates to a method for building a structure which is comprised of assembling a plurality of skeletal building blocks formed from rods or bars and the building block system incorporated in the method.
BACKGROUND OF THE INVENTION
Historically, man has created structures from masonary blocks. This form of building traces its ancestory from the earliest structures which were piles of rock to contemporary cut stone systems and from sun backed brick to the contemporary trend of utilizing kiln fired bricks and cast cement blocks.
Structures utilizing masonary techniques has become increasingly costly due to the labor and energy involved in transporting the materials to the place of construction and erecting the structure. Masonary items such as brick, cut stone or concrete block are extremely heavy and a significant amount of energy is expended transporting them from their place of origin to the building site. Furthermore, skilled masons are required to lay up the building blocks, whether they be brick stone or cement and mortar is required to secure the blocks together. Thus the cost of a masonary structure is a function of considerable energy expended in transporting the materials and a significant amount of skilled labor in handling the mortar and blocks.
A second contemporary means of construction consists of fabricating a structure from a framework of sawn boards and covering the framework with siding and plater board type materials. This latter method of construction is not as sturdy as the block construction and like the block system, does not provide adequate thermal insulation. Furthermore, the wooden structure is prone to fire and insect damage and it requires constant maintenance to prevent deterioration.
OBJECTIVES OF THE INVENTION
In view of the obvious shortcomings of the various contemporary building methods, it is an objective of this invention to provide a building block which may be assembled by an unskilled laborer without the aid of mortar to create structures having plumb walls and square corners and insulative and structural integrity that is greater than masonary techniques but requires less man power to assemble than a woodframe structure.
A further objective of the present invention is to provide a method for fabricating a structure which includes assembling a number of blocks comprised of pre-formed rods or bars.
A still further objective of the present invention is to provide a building structure comprised of a plurality of interlocking blocks fabricated from formed rods or bars which include interlocking appendages.
It is a further objective of the present invention to provide a building module fabricated from rods or bars that are shaped in the form of a block and incorporate appendages that will interlock the modules to permit fabricating a structure to meet the needs of the user.
Another objective of the present invention is to provide a method for building a structure comprised of assembling formed skeletal modules, inserting nailing strips in recesses provided therein, securing external and internal facing materials to the modules by nailing the facing materials to the nailing strips and filling the void between the internal and external facing panels with an insulating material.
A still further objective of the present invention is a provide a method for building a structure comprised of assembling formed skeletal modules, inserting nailing strips in recesses provided therein, securing facing materials to one side of the modules by nailing the facing materials to the nailing strips and spraying a masonary or resinous insulating and weatherproofing material over the exposed side of the skeletal modules and back to the facing materials to complete a wall structure.
The foregoing and other objectives of the invention will become apparent in light of the drawings, specification and claims contained herein.
SUMMARY OF THE INVENTION
Presented hereby is a building block or module which is fabricated by forming metal, plastic, fiberglass, or any other suitable rod like materials to create a skeletal structure having dimensions approximately equivalent to contemporary building blocks. The skeletal building blocks include recesses formed in at least one side along the midline which are dimensioned to receive nailing strips to which a facing panel may be secured. The skeletal blocks are provided with appendages which lock on to adjacent blocks so that a structure may be fabricated by stacking the blocks in a conventional staggered manner similar to that used in masonary construction.
A structural wall formed from a plurality of the skeletal blocks is completed by inserting nailing strips in the provided recesses and nailing a facing material along one or both sides of the block wall. Insulating material may be inserted in the hollow spaces between the facing materials or if desired, facing material may be applied to only one side of the wall and the other completed by spraying a masonary product or other suitable material over the exposed skeletal structure and back of the facing material to build up a thickness equivalent to the width of the blocks.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a 3-4 view of a preferred embodiment of the building block of the present invention.
FIG. 2 is a cutaway view illustrating a base structural strip embodiment of the present invention.
FIG. 3 is a cutaway view illustrating a wall fabricated from the structural blocks of the present invention and incorporating facing paneling on both sides.
FIG. 4 is a cutaway view of a wall fabricated from structural blocks of the present invention utilizing facing paneling on one side and sprayed material on the other.
DESCRIPTION OF THE INVENTION
FIG. 1 illustrates the basic, skeletal building block upon which this invention is predicated and which is incorporated in the various methods of structure fabrication taught herein. The block is comprised of a framework which may be fabricated from a metal rod or heavy gauge wire calculated to meet the anticipated stress which will be encountered in the structure fabricated from a plurality of similar blocks. The materials for forming the structure of the block do not have to be metal rod or wire. They can be bar or sheet shaped and fabricated from metal, platic, fiberglass, boron filament, or a wide variety of materials having the required physical properties which will enable the creation of a strong and resilient structure.
The preferred embodiment illustrated in FIG. 1 incorporates a top rectangular section 11 and a bottom rectangular section 12. Both the top and bottom rectangular sections are exactly identical in shape and dimension and include rectangular recesses 13 and 14 located at the midpoint of each side. These recesses are dimensioned to receive furring or nailing strips which will permit facing material to be secured to the blocks.
The top and bottom rectangular sections 11 and 12 are joined by a plurality of rod like structures of equal length so that the top and bottom rectangular sections 11 and 12 will be parallel in the completed skeletal block.
In FIG. 1, four rods 15 are located at the inside corners of the furring strip receiving recesses 13 and 14. These rods may be secured to the top and bottom rectangular structures by any convenient means but in the preferred embodiment they are welded in place.
The outer corners of the furring strip receiving recesses of the top 11, and bottom 12 rectangles are joined together by rods 16 which are secured to the top and bottom rectangular frameworks in a manner similar to that described for rods 15. The bottom ends of rods 16 incorporate a rectangularly shaped hook section 17 dimensioned to cooperate with the top rectangular section of a block position immediately beneath it. To accomplish this, the rectangular hook section 17 has an upper section 18 which is perpendicular to the major portion of rod 16 connecting the top and bottom rectangles together. The perpendicular section 18 has an inside face that is equal in length to the diameter of the material forming the bottom rectangular structure 12. A section 19 descends from section 18 in a plane parallel to the major portion of the rod which interconnects the top and bottom rectangles. Section 19 has an inner face which has a dimension equivalent to the diameter of the material forming the bottom rectangle 12 plus the diameter of the material forming the top rectangle 11 of the skeletal block to which it is going to be attached. A lower section 20 extends from section 19 parallel to section 18. Section 20 has an inner face length equal to the diameter of the top rectangular section of the block to which the illustrated block is to be secured. Thus, the bottom portion of the connnecting rods 16 incorporate a hook section 17 which is generally rectangular in shape and which forms a recess that will accommodate the rod structure of the bottom rectangle of the block into which rod 16 is incorporated and the rod structure of the top rectangle of the skeletal block to which the illustrated block is to be attached.
In assembling a structure similar to that illustrated in FIGS. 2, 3, and 4, the hook sections 17 engage the top rectangle of the lower block structure when the sides of the bottom rectangle are compressed to allow the bottom portions 20 of the hooks 17 to pass the top rectangle of the lower block and then allowed to return to their normal position due to the resiliency of the materials with which the lower rectangular section 12 is fabricated.
The corners of the top rectangle 11 and bottom rectangle 12 are joined by vertical rods 21 which are secured in a fashion similar to the rods 15 and dimensioned so that the top and bottom rectangles will be parallel when the block is assembled. The corner support rods 21 incorporate an off set section 22 which passes around the rod structure of the bottom rectangle 12 and descends a distance therebelow which is equal to at least the diameter of the structure of the top rectangle of the block to which the illustrated block is to be attached to. When the blocks are assembled in a staggered fashion, the off set portions 22 of corner rods 21 will occupy a position immediately behind vertical support rods 16 of the block located directly below and the hook sections 17 will engage the top rectangular frame of the lower block immediately behind the corner brace rods 21 of the lower block.
In the preferred embodiment illustrated in FIG. 1, additional vertical rods 23 are positioned inboard of the corner rods 21. The vertical rods 23 incorporate an off set portion 24 located at the bottom which is similar to the off set portion 22 of vertical rods 21. Vertical rods 23 are secured between the top and bottom rectangular structures in a manner similar to that utilized for the other vertical rods in the structure and they are displaced from the corner rods a distance which will cause the off set portions 22 to be adjacent to the sides of the rectangular recess in the lower block, see FIGS. 2, 3 and 4.
FIG. 2 illustrates a footer string which is comprised of a plurality of skeletal blocks similar to that illustrated in FIG. 1 except the vertical rods 16, 21 and 23 are the same lengths as rods 15 and they do not incorporate their respective hooks or off set portions 17, 22 or 24.
The trunk line section of FIG. 2 is comprised of a plurality of skeletal blocks which are interconnected by securing the blocks together with sections of rod 31 which may be secured to adjacent top rectangular sections or bottom rectangular sections by welding or any other convenient means dependent upon the materials used. The interconnecting rod sections 31 are dimensioned so that a space will be created between adjacent skeletal block which is equivalent to the recesses in the sides of the top and bottom rectangles of the blocks. Thus when blocks are assembled in a staggered fashion as illustrated, a continuous channel is formed between the space between blocks and the rectangular channel in the side of the block immediately above, see the interrelationship between blocks 32, 33 and 34.
The trunk line section may be braced by securing bracing rods 36 between selected vertical rods of the blocks forming the trunk line section. This technique may be utilized to brace additional sections of the wall after the blocks have been assembled to the trunk line section. However, if additional bracing is utilized between the blocks secured to the top of the trunk line sections, any additional welding or similar fastening step will have to be incorporated in the wall assembly process. It is anticipated that trunk line sections will be placed in a concrete footer by placing the trunk line in the footer excavation along with the reinforcing rods 41 before the footer is poured. This will result in the bottom rectangle sections of the blocks comprising the trunk line forming part of the footer reinforcing network and it will eliminate the need for a portion of the reinforcing metal required by most building codes.
Trunk line sections similar to those illustrated in FIG. 2 may also be used as the top course of blocks in a wall to provide a more rigid support for roof or floor beams. The top course of a wall may also be covered with a plate such as a large timber or steel beam to provide a rigid surface for supporting beams. Shorter trunk line sections may also be used as lintels over window or door openings.
FIG. 3 illustrates a wall constructed from a plurality of blocks similar to those illustrated in FIG. 1. The blocks may be assembled on trunk line sections to those illustrated in FIG. 2 with the trunk line set in a concrete footer or secured to the floor surface by some other convenient means. If desired, the trunk sections may be eliminated and the lower course of blocks may be comprised of standard blocks as illustrated in FIG. 1 but positioned in an inverted orientation so that the bottom rectangular sections of the lower course of skeletal blocks will mate with the lower rectangular sections of the second course of blocks. This will provide additional security between the first and second course of skeletal blocks and provide a level surface without hook or off set protrusions to facilitate setting the wall on a wood surface or an existing concrete surface.
When a basic wall is assembled from the skeletal blocks as illustrated in FIG. 3, nailing strips 51 are forced into the channels formed by the rectangular recesses in the sides of the skeletal blocks and by the spaces between adjacent blocks. In a preferred embodiment, the skeletal blocks are 143/8 inches long and the rectangular recesses are 15/8 inches wide so that when the blocks are assembled in a wall in a staggered fashion as illustrated in FIG. 3, the nailing strips will be on 16 inch centers. Any convenient dimensions may be utilized for the blocks, however to be compatible with the standards currently used in the industry for masonary blocks and various code requirements for 16 inch centers for studding, it is suggested that the preferred dimensions for the skeletal blocks would be 143/8 inches long by 8 inches high with widths similar to those used in concrete blocks such as 2 inches, 4 inches, 6 inches, 8 inches and 12 inches. The rectangular recesses may be any size desired, but it is suggested that an internal dimesnion of the recesses equal to 15/8 inches wide by 3/4 inch deep so that the resultant channels will accept a commercially available standard wood strip.
Once the nailing strips 51 have been inserted in the channels created by the blocks, a facing material 52 and 53 may be nailed to the nailing strips 51. If the wall is an outside wall, the exterior facing panel 52 may be similar to the sheeting used in frame structures, aluminum siding or any convenient weatherproof material. The interior side of the wall 53 may be faced with wall board, paneling or any desired paneling material.
In an alternate embodiment of the present invention, the nailing strips may be eliminated and the panel material may be secured directly to the rods forming the skeletal blocks with hook or U bolts 54 and 55 respectively. If this method of fastening the paneling material to the skeletal blocks is utilized, the rectangular recesses in the sides of the blocks may be eliminated. The rectangular recesses may be eliminated on one or both sides without destroying the integrity of the structure or the ease of assembly. For instance, the blocks on the left side of FIG. 3 are illustrated with no nailing strip channels but block spacing is maintained because the hook sections 17 of upper blocks cooperate with the corners of lower blocks.
After the wall facings 52 and 53 have been installed, insulating material 56 may be poured between facing panels 52 and 53 to create a wall having insulating qualities significantly better than prior art structures.
FIG. 4 illustrates an alternate wall construction where a facing panel 62 is secured to the wall via nailing strips 61 or similar means such as suggested with respect to FIG. 3. After the facing panel 62 is installed, the skeletal block side of the wall is coated with a sprayed on structural material such as cement applied with a spray technique or stucco to a thickness which will cover the blocks and provide a smooth, wear and weather resistant surface 63.
The nailing strip channels are not required in the sprayed side of the wall illustrated in FIG. 4 but their inclusion will not destroy the integrity of the wall. Thus, standard blocks having recesses on both sides may be used for all types of construction anticipated for the skeletal block of the present invention.
As previously suggested, a wide variety of materials may be utilized to fabricate the construction blocks described herein. However, the preferred embodiment anticipates the use of steel rods or wires which may be formed in a wire bending machine and then welded together to form the blocks. The table below indicates the anticipated compressive strength of wire blocks formed from 3/16 inch, 7/32 inch and 1/4 inch diameter steel wire.
______________________________________3/16 φ Wire ##STR1##(Block wt. = 1.735 pounds) ##STR2## P = 619,188 Pounds/Wire × 16 Wires = P = 9907 Pounds/Block Pounds7/32 φ Wire ##STR3##(Block wt. = 2.357 pounds) ##STR4## P = 1135.1787 Pounds/Wire × 16 Wires = P = 18.162 Pounds/Block Pounds1/4 φ Wire ##STR5##(Block wt. = 3.083 pounds) ##STR6## P = 2012.3623 Pounds/Wire × 16 Wires = P = 32,197 Pounds/Block______________________________________
The commpressive strength does not vary as a function of the block size because 16 vertical wires are used whether the blocks are 2 inches wide or 12 inches wide. However, the block weight will vary as a function of the material incorporated in the top and bottom rectangular structures. The block weights given in the table above are exemplary for 8 inch wide blocks.
A typical method of building a wall utilizing the skeletal construction blocks of the present invention is to prepare a footer excavation, lay in the reinforcing rod, lay in trunk line sections the length of the wall to be constructed, and pour the concrete footer. After the footer has set, skeletal construction blocks are connected to the trunk line section and interconnected by compressing the lower sides of a block so that that hook sections 17 will pass inside the rectangular top sections. Once the hook sections 17 have passed inside the rectangular top section of a lower block, the compressive force is released and the resiliency of the structure snaps the hook sections about the top section of the lower block so that an assembly similar to that illustrated in FIGS. 2, 3 and 4 is created. Alternate methods may be used to secure the blocks together, for instance the hook and off set portions 17, 22 and 24 of FIG. 1 may be eliminated and the blocks may be secured by welding them in place or bolting them together with U bolts. If desired, additional rigidity may be incorporated into the structure utilizing the preferred hook and off set sections by welding the blocks together after they have been secured together by the hook section 17 and off set sections 22 and 24.
Regardless of the means to secure the skeletal construction blocks together, additional rigidity may be incorporated into the structure if desired by performing the steps of positioning bracing means similar to the bracing wires 36 of FIG. 2 within the wall structure and welding the bracing wires to the blocks.
When the block wall has been constructed, nailing strips are forced into the channels and facing panel nailed to the nailing strips. If desired, a wall may be insulated by performing the step of pouring an insulating material in the void formed by facing panels on either side of the construction.
An aternate method of completing the wall structure may be accomplished by building a wall as previously described and facing only one side with a facing material. After the facing panel has been installed, cement may be blown over the wire block and against the facing panel to a thickness which exceeds the width of the wire block so that a smooth concrete surface results.
Another alternate means of finishing the structure is to build a wall and face it on one side using the steps previously set forth and attaching brick ties to the remaining unfinished side of the wall. When the brick ties have been affixed to either nailing strips or directly to the skeletal construction blocks, a brick or stone course may be laid against the blocks to create a desired decorative effect. After the brick or stone course has been laid, the space between the interior facing panel and the brick or stone work may be insulated by pouring an insulating material such as fiberglass between the two wall faces.
While preferred embodiments of this invention have been illustrated, variations and modifications may be apparent to those skilled in the art. Therefore, I do not wish to be limited thereto and ask that the scope and breadth of this invention be determined from the claims which follow rather than the above description.
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A construction method for fabricating structures and a system of building blocks utilized in the method is presented. The blocks are skeletal and formed from heavy gauge rods or bars with straight and hook projections that permit the blocks to be interconnected. Recesses are provided in the blocks so that an assembly of blocks will accommodate furring strips or stringers which will add to the structural integrity of the block structure and provide a nailing surface.
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BACKGROUND OF THE INVENTION
The present invention relates to a guide for pieces of fabric that include accessories such as pockets, belts, etc., in a sewing unit having a conventional sewing machine equipped with a needle and known types of feeding mechanisms which define a sewing axis along which the pieces of fabric are advanced in order to be assembled.
Conventional sewing machines are also provided with guides consisting of plates which are disposed one above the other and spaced apart from one another so as to form separate channels in which the pieces of fabric to be joined together are guided so as to enable them to slide separately during the sewing operation.
These guides, which are normally located in the vicinity of the sewing machine needle, are adapted to guide the pieces of fabric towards the needle in a manner to match their respective edges and to orient them with respect to the sewing axis according to the particular outer profile of the workpiece.
Consequently, the above mentioned means of joining together pieces of fabric is carried out in such a way that the pockets, which have already been attached, present an obstacle when the pieces of fabric are being advanced between the plates which form the guide. It is therefore necessary to carry out two preliminary operations: the first is that of temporarily removing the guide from the zone of passage of the pieces of fabric when the part containing a pocket is being sewn.
It is necessary to remove the guide in this manner to prevent the intermediate plate of the guide, which separates the pieces of fabric, from being inserted in one of the pockets, which, as is known, are disposed between said pieces of fabric, and which would prevent the pieces of fabric from sliding freely in the guide.
The second preliminary operation is that of manually guiding the pieces of fabric when stitching those portions provided with pockets so as to maintain the pieces of fabric correctly oriented and matched when the guide has been removed.
These preliminary operations are responsible for what is considered a considerable loss of time relative to the total sewing time which prevents the operator from performing other preparatory operations on other pieces of fabric to be assembled or from loading other sewing units.
The returning of the guide to the zone of passage of the pieces of fabric is normally accomplished by a pneumatic control means and necessitates special attention by the operator to assure that the pieces of fabric are correctly inserted in their respective guide channels.
The object of the present invention is to eliminate the aforementioned preliminary operations and also eliminate the delayed insertion of the pieces of fabric in the guide when the work cycle is already in progress.
The technical problem to be solved in order to achieve this object is that of inserting the pieces of fabric to be assembled in the guide before commencing the work cycle by placing the guide per se in a position in which it will not interfere with accessories which were previously attached to the pieces of fabric.
SUMMARY OF THE INVENTION
This technical problem is solved by means of a guide of the aforementioned type provided with the following features:
a. a guide equipped with plates which are disposed one above the other and spaced apart from one another so as to form two channels in which the separate pieces of fabric are caused to slide separately;
b. a support means for the guide which is movable parallel to the sewing axis;
c. a gripping and holding means for clamping the pieces of fabric temporarily in the guide while they are being advanced to the stitching instrumentalities;
d. a control device for the gripping means;
e. first control means for the control device acting on the latter at the beginning of the work cycle so as to activate the gripping means; and
f. second control means operatively associated with the first control means for the gripping means upon termination of sewing the part of the pieces of fabric comprising the accessories; the guide being caused to move from a loading position to an operating position directly by the pieces of fabric through the intermediary of the gripping means.
Other features and advantages of the present invention will be made apparent in the following detailed description thereof which is provided with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a sewing unit equipped with the guide according to the present invention;
FIG. 2 shows a pneumatic control circuit for the device shown in FIG. 1;
FIG. 3 is a cross-section of the guide;
FIG. 4 is a diagrammatic view of a workpiece sample to be assembled; and
FIG. 5 is a rear view of a feature of a modification of the guide.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the guide 1 according to the invention is associated with a sewing unit comprising a conventional sewing machine 2 having a needle 3 and a presser foot 4 pressing in a conventional manner on a throat plate 5 from which the conventional feeding mechanisms (not shown) project periodically.
The feeding mechanisms together with the needle define a sewing axis 6 along which the workpiece consisting of two pieces of fabric to be joined is advanced.
The workpiece may consist, for example, of pant sections 100, at least one of which is provided with a pocket 101 (FIG. 4).
The guide 1 is disposed forwardly of the sewing machine 2. The guide 1 consists essentially of two vertical supports 7 and 8 which are supported on the work bed plate 9 of the sewing unit and which are spaced apart from one another. Horizontally disposed between the vertical supports 7 and 8 is a slide bar 10 and two retaining bars 11 which are arranged one above the other and in a retracted position with respect to the slide bar 10.
A support means or carriage member 12 for a fabric guide 13 is mounted on the slide bar 10.
The support means consist essentially of a movable support block 14 having a suitable slide bushing 15 through which the aforementioned slide bar 10 extends.
As shown in FIG. 1 one side of the movable block 14 has a support arm 16 fixed thereto by any suitable means not shown and adjustably supports a horizontally disposed shaft 17 therein.
This adjustment feature is provided to enable the guide 13 to be correctly positioned with respect to the sewing axis 6.
More specifically, the positioning of the guide 13 serves to adjust the distance between the stitching to be formed and the edge of the fabric that is guided within the guide.
One end of the horizontal shaft 17 extends between and in a plane normal to the axis of the retaining bars 11 which are spaced apart from one another by an amount corresponding to the thickness of said horizontal shaft so as to permit longitudinal movement thereof without pivoting about the slide bar 10.
A depending support 18 is attached to the opposite end of the horizontal shaft 17 and serves to support the fabric guide 13 by means of an "L" shaped bracket 19.
As shown more clearly in FIG. 3, the fabric guide 13 includes an upper plate 20, an intermediate plate 21 and a lower plate 22 which are disposed one above the other and in spaced relation which defines two channels within which the separate pieces of the fabric workpiece are caused to slide so as to be matched and oriented with the sewing axis 6.
The depending support 18 is provided with a bracket member 23 which serves to support a gripping and holding means identified generally in FIG. 1 by numeral 24. The gripping means 24 includes a vertically disposed pneumatic cylinder 25 whose piston rod 26 overhangs the lower plate 22 of the fabric guide 13 and with which it makes contact to temporarily block both of the aforementioned pieces of fabric while the gripping means 24 is actuated in a manner that will be more fully described hereinafter in the paragraph entitled "Mode of Operation".
An end-of-stroke actuator 27 in mounted adjacent one end of the slide bar 10 so as to cooperate with the support means 12 of the guide at the end of its travel which the latter performs while guiding the pieces of fabric to be assembled.
The end-of-stroke actuator, which defines the operating position of the fabric guide 13, is adjustably mounted in the support 8 to which a support plate 28 is also attached. Blocking means consisting of a pneumatic cylinder 29 is mounted on the support plate 28. The piston rod of the cylinder 29 is provided with an end 30 which is designed to be inserted in a corresponding hole 31 provided in the support arm 16 of the support means 12.
Lastly, the guide 1 is equipped with pneumatic return means 32 for the guide 13 and includes a pneumatic cylinder 33 whose piston rod 34 carries a depending lug 35 on its free end that is adapted to make contact with the block 14 of the support means 12 in order to move the latter from its operating position adjacent to the sewing machine 2 to a loading position for the separate pieces of the fabric workpiece.
The loading position is spaced from the sewing machine and is defined by an adjustable collar 36 assembled as shown in FIG. 1 on the slide bar 10.
Referring now to FIG. 2, the pneumatic control circuit for the guide 1 is provided with a main conduit 37 that is connected to a conventional compressed air source 38 and from which leads a conduit 39 connected to a control device consisting of a distributor box 40 connected by means of the conduits 41 and 42 to the gripping means 24.
A first control means for the control device is supplied from the main conduit 37 by means of a conduit 43. This control device includes a first electrovalve 44 connected by a conduit 45 to a pressure valve 46 which is connected by means of a conduit 47 to the pilot mechanism of the distributor box 40.
The main conduit 37 also supplies a second control means for the control device by means of a conduit 48.
The second control means has a second electrovalve 49 acting on the pilot mechanism of the aforementioned distributor box 40 by means of a conduit 50 from the opposite side to that of the first electrovalve 44.
The first electrovalve 44 is activated by an electric pulse corresponding to the starting of the sewing unit while the second electrovalve 49 is activated by the end-of-stroke actuator 27 on which the support means 12 of the guide 13 act at the end of the movement which the latter performs while guiding the pieces of fabric to be assembled.
The second electrovalve 49 acts on the pilot mechanism of the pressure valve 46 of the first control means by way of another conduit 51 via a common stroke regulator 52.
The conduits 50 and 51 are also used to supply the pneumatic cylinder 29 of the blocking means such that when the second electrovalve 49 is activated the support means 12 is blocked, and also the guide 13 in its operating position.
Lastly, the main conduit 37 supplies compressed air to the return means 32 which includes a valve 53 whose pilot mechanism is controlled by means of a conduit 54 directly by a conventional pneumatic device (not shown) for raising the presser foot of the sewing machine.
The valve 53 is connected by means of conduits 55 and 56 to the pneumatic cylinder 33 of the return means 32.
A stroke regulator 57 is provided on the conduit 56.
MODE OF OPERATION
Before starting the work cycle the presser foot 4 is first raised by the operator so that the leading edges 102 of the pieces of fabric 100 to be assembled can be inserted.
When the presser foot is raised, a pneumatic pulse acts on the pilot mechanism of the valve 53 putting it into the position shown in FIG. 2 which corresponds to the supplying of the conduit 56.
As a result, the depending lug 35 is moved in a direction to engage the block 14 and is effective in moving the latter and the support means 12 to the loading position of the guide.
The space between the loading position and the needle 3 of the sewing machine is such as to include those portions of the pieces of fabric provided with the pockets 101 and thus prevents interference between the latter and the intermediate plate 21 of the guide 13.
Immediately after termination of the preliminary step of inserting the aforementioned leading edges 102 beneath the presser foot the operator inserts the separate pieces of fabric into their respective channels of the guide 13 and then actuates the means for lowering the presser foot.
Following the lowering of the presser foot, the conduit 54 ceases to be supplied and the valve 53 switches the air supply from the conduit 56 to the conduit 55, causing the depending lug 35 to be moved away from the movable block 14 toward the sewing machine and thus allowing the support means of the guide to be displaced without any impediment or obstruction.
The sewing machine is now started and an electric pulse reaches the first electrovalve 44, causing it to open and thus acting on the pilot mechanism of the distributor box 40.
As a result, switching occurs from the conduit 39 to the conduit 41 which produces the lowering of the rod 26 of the gripping means on the underlying pieces of fabric such that the latter are held against the lower plate 22 of the guide 13. The guide is therefore drawn towards the sewing machine 2 and during this movement it keeps the pieces of fabric aligned according to the sewing axis 6.
More specifically, stitching is also executed parallel to the profile of the edge in the part occupied by the pockets owing to the fact that an auxiliary guide 13a is provided in a fixed position adjacent the presser foot 4.
This auxiliary and conventional type guide is effective in moving the aforementioned portions of the fabric at right angles to the sewing axis 6 by means of its respective vertical wall 13b.
Thus, although the pieces 100 have a curvilinear edge in the portions occupied by the pockets, as shown in FIG. 4, the wall 13b is effective in maintaining the edge in perfect alignment with the sewing axis 6.
The movement of the guide 13 stops when the movable block 14 comes into contact with the end-of-stroke actuator 27.
The end-of-stroke actuator 27 closes the electric feed circuit of the second electrovalve 49 which leads from that of the first electrovalve 44 -- as a result of which it is possible to obtain excitation of the second electrovalve if the first electrovalve 44 is excited.
Excitation of the second electrovalve 49 causes switching from the conduit 48 to the conduit 50 resulting in the admission of compressed air into the cylinder 29 of the blocking means causing the end 30 to enter the hole 31 in the support means 12 so as to lock it in that position corresponding to the operating position of the guide 13.
The supplying of the conduit 50 simultaneously causes the activation of the distribution box 40 which switches the conduit 39 to the conduit 42, moving the rod 26 upwardly and out of engagement with the pieces of fabric.
Switching of the distributor box 40 is possible due to the fact that the flow of compressed air in the conduit 52 has ceased and as a result the valve 46 interrupts the admission of compressed air to the pilot mechanism of the distributor box 40.
The pieces of fabric to be assembled are now free to continue their movement towards the sewing machine, sliding in the guide which remains closed. Although the guide is first adapted to serve as a clamp together with the gripping means 24, it completes its function in cooperation with the auxiliary guide 13a, to match and orient the edges of the fabric according to the sewing axis 6.
As soon as the work cycle is terminated the sewing machine stops, causing a cessation of excitation of the first electrovalve 44 which interrupts the flow of compressed air to the valve 46. The second electrovalve 49 also ceases to be excited, causing the restoring of the pneumatic connection with the conduit 51 which terminates the disengagement of the end 30 from the hole 31 and the pre-arrangement of the valve 46 for the connection of the conduit 45 with the conduit 47.
As the presser foot 4 is automatically raised at the end of the work cycle, the valve is also activated by the feed through the conduit 54.
The compressed air flow thus passes from the conduit 55 to the conduit 56 causing activation of the return means 32 and longitudinal movement of the piston rod 34 of the cylinder 33 which is effective in returning the guide 13 to its loading position and in readiness for the next work cycle.
According to a possible modification of the return means 32 (FIG. 5), the support means 12 is connected to a cable 103 which is operatively connected to a first pulley 104 rotatably mounted on a plate 105 that is attached to the support 7.
Cable 103 extends through an eye 106 provided in a counter-weight 107 which is slidable carried within a cylindrical member 108. This cylinder member is assembled in an opening 109 in the work bed plate 9 and depends from the latter in a conventional manner.
The cable engages a second pulley 110 and adjacent to the latter is provided with another counter-weight 111 which exerts a slight pull on said cable so as to prevent any twisting thereof.
One end of the cable 103 is attached to the plate 105. The cylindrical member 108 is closed at its lower end by means of a pneumatic cylinder 112 which performs the same function as the pneumatic cylinder 33.
During the movement of the support means 12 of the guide 13 the pneumatic cylinder 112 is actuated so that its respective piston rod 113 is fully extended and is effective in maintaining the counter-weight 107 in its uppermost position within the cylindrical member and 108 corresponds to the total displacement of the support means for the guide. With the counter-weight in this position there is no pull on the pieces of fabric during the entire stage of sewing those portions of the workpiece which include pockets.
The tensioning counter-weight 111 acts on the cable 103 only in this state in opposition to the drag exerted by the pieces of fabric, but without negatively influencing the stitching produced in the latter.
As soon as the work cycle has been terminated the reversal of the feed to the cylinder 112 causes the re-entry of the piston rod 113 and thus the lowering of the counter-weight 107 which returns the support means 12 to the loading position against the adjustment ring 36.
The use of the guide according to the present invention eliminates any preliminary operations other than that employed to insert the pieces of fabric to be assembled beneath the presser foot of the sewing machine and in the guide per se prior to commencing the work cycle, and necessitates no further intervention on the part of the operator.
In the above description specific reference has been made to the use of the device according to the invention for assembling parts of pants, at least one of which is provided with a pocket. However, it is obvious that the use of the device can be extended to assembly operations involving pieces of fabric which do not include accessories but wherein it is important for accompaniment to be provided for a specific initial section.
The type of guide can also differ from the one described. For example, it is possible to provide a single channel in which one or more pieces of fabric can slide without departing from the scope of the present invention.
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A workpiece guide for a sewing unit for guiding pieces of fabric having accessories such as pockets, belts or the like to the stitching instrumentalities of a sewing machine. The guide is movable from a loading position to an operating position along the sewing axis by means of a gripping device carried by the guide which temporarily clamps the workpiece in an area devoid of accessories. In timed sequence with the work cycle, control devices automatically release the workpiece and return the guide to the loading position in readiness for the next work cycle.
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BACKGROUND OF THE INVENTION
The present invention pertains to an improved cutting device for trimming adjacent edges of pieces of fabric being joined by means of flat seam stitching with a covering stitch in a sewing machine. When two pieces of material are to be joined by seaming in a manner whereby their sewn edges are disposed in co-planar and contiguous relation, it is common practice to feed the two pieces into the machine so that the finished and joined edges are formed adjacent to the original edges of each piece which are severed from the latter immediately prior to the seaming operation. This is accomplished by positioning the pieces so that the major portion of both are disposed on the same horizontal plane and with the adjacent edges of each being turned at right angles to said horizontal plane and in abutting relationship with one another. These abutting edges are caused to enter a guide formed in the machine's presser foot and are severed from the two pieces just prior to the latter being subjected to the seaming operation of the flat-seam and covering stitch type.
To perform seaming operations of this type which are commonly referred to as cut-stitch operations, trimming devices are provided which include a fixed blade disposed horizontally in the base of the presser foot and which extends perpendicular to the direction of advance of a workpiece. Such trimming devices also include a movable blade carried by a movable support which locates it in operative association with the fixed blade and the movable support is operatively connected to any suitable actuating means forming a part of the machine itself. The movable support is also provided with a biasing means which serves to maintain contact between the fixed and movable blades. The presser foot is attached to the lower end of the fabric presser bar which is supported in the frame of the sewing machine and in a known manner is continuously biased by spring means associated with said presser bar in the direction of the usual needle plate which is mounted in the machine's worksurface that supports the workpieces during the sewing operation. A conventional transport means or feed dogs cooperate in a known manner with the underside of the presser foot to effect advance of the workpiece during the seaming operation. The biasing means operatively associated with the movable support is adapted to act on the movable blade so as to continually urge it into contact with the fixed blade even when the presser foot is being displaced in an upwardly direction away from the needle plate.
In the known type of trimming devices described above, the fixed blade is supported in the base portion of the presser foot so as to be in relatively close proximity with the needle plate and the movable blade is located above and in operative association with said fixed blade. The biasing means for the movable support serves to maintain the two blades in operative contact by pressing downwardly on the movable blade thus effecting its actuation in a positive manner. This downward force on the movable blade coupled with the biasing means acting on the presser bar subject the feed dogs, to what is considered, an excessive amount of downward force by the presser foot. As a result of this the feed dogs in order to perform their intended function must overcome the combined forces of both biasing means associated with the presser bar and movable blade.
It must be understood that both of these biasing means must be capable of producing selected and accurate amounts of force which differ one from the other in view of the function each is caused to perform. In particular, the biasing means for the presser bar should be such that the force it exerts while cooperating with the feed dogs will not have any damaging effects on the structure of the workpiece being advanced therebetween. Additionally, the biasing means for the movable support must be sufficient to maintain operative contact between the two blades without subjecting them to too great a biasing force which would result in excessive wear and a shortened life expectancy of said blades. These factors are considered serious in known trimming devices for it is quite difficult and time consuming to obtain the most desirable setting of each of the two biasing means so that the forces they provide will be the most advantageous for the particular characteristics of the material forming the workpiece.
Additionally, the biasing means for the movable supports in the known trimming devices are subjected to compression forces caused by the upward movement of the feed dogs which passes through the fabric to the presser foot and in a direction that opposes the spring force pressing on said fabric and being directed in an upwardly direction, said compression forces are transmitted to the biasing means acting on the movable blade. This condition occurs when contact between the two blades is such that their cutting edges are in spaced relation which defines their inactive or rest position and places undue stress on the movable blade. This condition also creates an unbalanced condition in the presser foot which can be attributed to the biasing means of the movable support that creates a greater degree of compression on the side of said presser foot at which said movable blade is operating.
As a result of the increased forces on one side of the presser foot, the fabric being advanced by the latter has a tendency to become misaligned or in other words, the fabric is urged to rotate out of alignment with the intended path it should follow during its advancement.
It is a general object of the present invention to eliminate the described disadvantages prevalent in known trimming devices.
A further object is that of lightening the loads on the elements which are in frictional contact and in contact with the fabric so as to substantially reduce wear between the blades and provide a means to maintain desired control of the forces acting on the presser foot during advancement of the fabric so that the latter accurately follows its intended and desired path toward the sewing zone.
SUMMARY OF THE INVENTION
According to the invention, these and other objects are acccomplished by an improved fabric trimming device in which the movable blade is disposed adjacent the base of the presser foot and in frictional contact with the underside of the fixed blade and includes a biasing means for maintaining said movable blade in contact with said fixed blade. Additionally, this biasing means is arranged to act on the movable blade in a direction opposite to that of the biasing means acting on the presser foot.
The feature of causing the biasing means associated with the movable support to act on the movable blade in a direction opposite to the biasing means acting on the presser foot provides a means whereby the desired amount of pressure between the two blades can be obtained and maintained which is best suited for the particular type of material forming the workpiece. Additionally, during the period when the feed dogs project above the needle plate there is a limited amount of release of pressure between the two blades for the fixed blade which is being raised with the presser foot permits the spring, forming the biasing means for the movable blade, to increase in length to the extent of slightly reducing the biasing force with which said movable blade engages said fixed blade.
The device according to the invention is effective in reducing frictional wear between the two blades to a minimum and to maintain the presser foot in a balanced state whereby its underside maintains full contact with the workpiece so that the latter advances along its intended path of travel without any deviations therefrom.
These and other objects of the present invention will become more fully apparent by reference to the appended claims and as the following detailed description proceeds in reference to the figures of drawing wherein:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a portion of a workpiece showing the invention's two cutting blades in operative association with the edges thereof;
FIG. 2 is a perspective view of a portion of a sewing machine showing the trimming device according to the invention applied thereto; and
FIG. 3 is a sectional view as seen looking in the direction of the indicating arrows of line III--III in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, a portion of a workpiece is shown in FIG. 1 which is formed by two pieces of material 10 and 11 with their respective edges 12 and 13 being folded to extend in side by side relation in a plane substantially perpendicular to that containing the remainder of said pieces. The two edges 12 and 13 to be trimmed are cut by two operatively associated blade elements which define a stationary or fixed blade 14 and a movable blade 15 which is caused to move alternately to and fro in the directions depicted by the arrow X and is effective in severing the edges to be trimmed at a point in time when the fabric pieces are stationary between two successive steps for advancing it. Immediately following the cutting area, a so-called flat-seam is being formed which includes seaming stitches 16 and covering stitches 17. This type of seaming is well known to those conversant in the art and to describe it in further detail at this time is considered unnecessary.
To accomplish the above cutting operation, the fabric pieces are fed onto the worksurface of the machine which includes the usual needle plate 18 that forms a part of said machine's framework 19 and the edges to be trimmed are inserted in an opening or guide passage 20 formed between two spaced arms (FIG. 2) of the presser foot. These edges are guided by a wall 22 forming the sides of the guide passage to the location of the blade elements 14 and 15 after which the severed edge portions are removed laterally by means of a guide 23. In FIG. 2 the indicating arrow Y identifies the direction of advance of the workpiece. The presser foot is identified by numeral 24 and includes a base portion 25 one side of which is adapted to fixedly support the fixed blade 14 therein by means of a screw 26. This fixed blade also includes a longitudinally extending finger 27 formed on one end thereof which serves to guide and maintain contact with the movable blade 15 when the latter during its movement is at a distance furthest from the location of performing its cutting function. As shown in FIG. 2 the needle plate 18 includes the usual openings generally indicated by numeral 28 which provide the well known means for the feed dogs 29 of the fabric transport device to perform its intended function. The feed dogs, in a known manner, travel in a generally elliptical pathway by being caused to move upwardly in the direction of the presser foot, thence in the direction of arrow Y and then downwardly and back to their initial position for repeating the cycle.
During the advancing movement in the direction Y and in particular at the start of this movement, the feed dogs of the transport device applies stress, via the fabric, on the presser foot, and produces an upwardly directed force on the latter. Advance of the workpiece is accomplished by means of the conventional sawtooth configuration 30 which forms the upper surface of the feed dogs 29. As shown in FIG. 2, the presser foot also includes the usual openings 31 through which the machine's needle (not shown) is caused to travel during the sewing operation.
The presser foot 24 is supported in a conventional manner by a support 32 connected to a fabric presser bar 33 which is housed so as to be slidable in the vertical direction within a sleeve 34. The fabric presser bar 33 is biased in a downwardly direction by means of a fabric presser spring 35 and the biasing force of the latter can be adjusted by means of a regulating plunger 36. The fabric presser bar transmits a pre-selected amount of force on the presser foot 24, which passes through the fabric and to the teeth of the feed dogs. When the feed dogs are raised, they cause simultaneous raising of the presser foot that results in a slight compression of the fabric presser spring 35 which increases the biasing force being applied to the presser foot.
The movable blade 15 is carried by a support arm 37 connected to the sleeve 34 and is caused to oscillate in the directions depicted by the indicating arrow Z by means of an eccentric member 38 operatively connected therewith which is mounted on a rotatably driven shaft 39. The means which operatively connects the eccentric member 38 with the support arm 37 includes a connecting rod 40 (FIG. 2) having a pin 42 which interconnects it with one end of an arcuated arm 43 whose opposite end is fixed on the sleeve 34 so as to cause said sleeve and support arm to oscillate about the axis of the fabric presser bar 33. This driven shaft 39 and the eccentric member 38 are housed in the upper horizontal arm (not shown) of the sewing machine.
The support arm 37 has a U-shaped bracket 44 forming that end opposite the end attached to the sleeve 34 and the arms of this bracket are identified by numerals 45 and 46. These arms 45 and 46 have bushings 47 and 48 respectively attached thereto in vertically aligned relation and serve to support a rod 49 for sliding movement therein. The lower end of rod 49 has a support block 50 fixed thereon which supports the movable blade 15 by means of a locking screw 51. From the support block 50 the movable blade 15 extends in the direction of and into an opening or guide passage 52 (FIG. 3) provided in one side of the presser foot 24. The location of the movable blade 15 is such that it is disposed below the fixed blade 14 and the latters longitudinally extending finger 27, in other words the movable blade 15 is closer to the needle plate with respect to the fixed blade 14. The biasing force of the movable blade 15 against the fixed blade 14 and the finger 27 is provided by means of a helical spring 53 which presses at one end against the bushing 47, which is fixed to the arm 45 of the bracket 44, and at the other end against a stop element 55 which is fixed on the rod 49 in an adjustable manner by means of a screw 56. A finger 57 on the stop element 55 rests against a vertically extending guide 58 which is fixed to the bracket 44 intermediate its arms 45 and 46 and serves to prevent oscillation of the movable blade 15.
In operation of the biasing force provided by the helical spring 53 is directed toward the stop element 55 urging the latter and the rod 49 upwardly so that the movable blade 15 is also urged upwardly into frictional contact with the fixed blade 14 and its longitudinally extending finger 27. Additionally, it is possible to regulate the biasing force which the spring 53 produces so as to provide the most desirable operating pressure between the two blades 14 and 15 which is independent of the biasing force provided by the fabric presser spring 35. When the presser foot 24 is raised by the feed dogs 29, the fixed blade 14 moves upwardly therewith and such movement subjects the spring 35 to further compression. As a result of this, the movable blade 15 is also raised under the action of the spring 53 and the biasing force provided thereby is reduced, so that there is a reduction in the biasing force by the knife 15 on the finger 27, if the advancing operation occurs when the blade 15 is in the rest position shown in FIG. 2. By causing the helical spring 53 and the spring 35 to direct their forces in opposite directions provides the necessary means for substantially reducing frictional wear between the two blades 14 and 15 and maintains the presser foot 24 in a balanced state so that the workpieces will not become misaligned from their intended path of advancement.
Although the present invention has been described in connection with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.
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A workpiece trimming device for sewing machines having a fixed blade mounted in one side of the machine's presser foot and a movable blade operatively associated with the underside of the fixed blade reciprocally driven within a passage formed on the opposite side of the presser foot in alignment with the fixed blade. A first biasing force acting on the presser bar continually urges the presser foot in the direction of the needle plate and a second biasing force acting in the opposite direction of the first maintains contact between the fixed and movable blades. The first and second biasing forces acting in opposite directions provides an improved means for controlling the intended functions of the presser foot and cooperating trimming blades.
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BACKGROUND OF THE INVENTION
This invention relates to a monitoring device for double threads in warp tying machines having a tying device, grippers for the groups of warp threads to be tied together, and a device for separating the outermost warp thread to move it out of the plane of the warp.
It is known to ensure the correct sequence of individual threads within the warp by inserting a so-called lease into the warp, in most cases with the aid of two leasing cords. In a device of this kind, as described in Swiss Pat. No. 619,011, the separating devices separate the outermost warp thread from the layer of warp threads by changing their position in relation to the layer of the warp threads together with the leasing cords after separation of a thread so that all threads following the next outermost warp thread are displaced by the latter. In this case, therefore, the separation of double threads is prevented by the cooperation of the leasing cords with the separating device.
Additional safety against the separation of double threads is achieved according to Swiss Pat. No. 348,937 by designing the separating device, e.g. a notched needle, in such a manner that it can only separate one thread.
If, however, a lease is used, then the prevention of separation of double threads depends solely on the correct choice of separating needle in accordance with the given yarn diameter. Even then, however, two or in exceptional cases even more than two warp threads are liable to be separated, especially if the warp threads have been sized. This has the undesirable result that the dying device produces a so-called three-legged knot. Two different types of problems then arise, depending on the position of the double thread:
If the double thread lies on the side of the old warp, i.e., if two warp threads of the old warp are tied to a warp thread of the new warp, then thread breakage occurs at the latest at the level of the first row of drop wires since the two threads of the double thread are drawn into different drop wires. This thread breakage must be repaired by the manual insertion of a piece of thread. In addtion, a missing warp thread must be supplied to the new warp from an edge of the group of threads for the second thread of the double thread.
If the double thread lies on the side of the new warp, i.e. if a warp thread of the old warp is tied to two warp threads of the new warp, then these two new warp threads together with one old warp thread are drawn through the associated drop wire, through a heald and through a tube of the reed. The fault is then not detected until the starting place is reached and one of the two new warp threads of the double thread must be cut off, pulled backwards out of the reed, heald and drop wire and deflected and removed at one side of the beam.
Apart from the fact that elimination of both these types of faults requires an undesirable amount of manual operation, the double threads are liable to impair the quality of the woven fabric. For example, if the number of warp threads which have had to be deflected and removed from the side exceeds a certain value, such as four, differences in tension are then liable to occur in the new warp resulting in a poor quality of weave.
It is therefore necessary to prevent the formation of three-legged knots. In other words, double threads must always be detected in good time before the tying process is performed.
The problem of detecting double threads is also found in other textile fields, for example in winding. German Auslegeschrift No. 1,560,548 discloses a winding machine having a monitoring device for the tying of double threads. The device comprises a measuring instrument for measuring the thread dimensions in the path of the thread downstream of the tying device. Measuring of the thread dimension may be carried out, for example, by optical means.
Optical measurement of the thread dimension always entails a certain risk of error due to dust formed in yarn processing. Moreover, it is not ideal to place the measuring instrument downstream of the tying device as this cannot prevent the formation of a three-legged knot.
The invention serves to provide a monitoring device for double threads which will not only effectively detect double threads and hence prevent the formation of three-legged knots but is also substantially immune to the presence of dirt and dust.
BRIEF SUMMARY OF THE INVENTION
The problem of three-legged knots is solved according to the invention by guiding the warp threads over a thread guide in the region between the separating device and a thread gripper so that the outermost warp thread is deflected over this thread guide as it is moved out of the plane of the warp. A measuring device is provided in the region of deflection of the outermost warp thread to measure the force exerted on the point of deflection or on the separating device by a deflected warp thread. A measuring signal obtained is used as the criterion for the presence of a double thread.
Measurement of the force in the region of deflection by a suitable sensor is virtually unaffected by dust and dirt if the sensor used consists, for example, of an elongation measuring strip, a piezoelectric sensor sensitive to deflection or a piezoelectric pressure convertor. Practical experiments have shown that the measuring signal obtained is twice as great from a double thread and three times as great from a triple thread as that obtained from a single thread and is therefore a reliable cirterion for the recognition of a double thread.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described below with the aid of constructional examples illustrated in the drawings wherein like reference numerals are applied to like elements and wherein:
FIG. 1 is a schematic representation of a warp tying machine equipped with a monitoring device according to the invention;
FIGS. 2 and 3 are two different views of a first embodiment given by way of example of a detail of FIG. 1;
FIG. 2 represents an enlarged partial section through the thread guide in the region of the sensor in FIG. 1 with the plane of section lying in the plane of FIG. 1;
FIG. 3 is an end view in the direction of the arrow III of FIG. 2 shown on an enlarged scale;
FIG. 4 shows another embodiment of the device of FIG. 1; and
FIG. 5 illustrates a third embodiment of the device of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows two groups of threads, K a and K n clamped between two gripper rails 1,2 and 1',2', the upper group of threads K a forming an old warp and the lower group of threads K n a new warp which is to be tied to the old warp. One of the two gripper rails for each group of threads K a and K n , e.g. the gripper rail 2 and the gripper rail 2', is displaceable in relation to the other rail of the group so that the tension in each group of threads K a and K n can be individually adjusted. The two adjustable gripper rails 2, 2' are arranged at zones spaced in the threadwise direction and located near the free ends of the threads K a , K n . In addition, the adjustable gripper rails permit tension to be adjusted in at least the edge portion of the group of threads.
The groups of threads K a , K n pass through the range of action of a tying machine 3. In practice, the tying machine 3 is placed at one of the two lateral edges of the groups of threads K a , K n and moved transversely to these groups of threads. With each successive cycle of operation, one thread of the old warp K a and one thread of the new wrap K n are tied together. The tying process basically uses a separating means or device 4, 4', respectively, for each of the two thread groups K a , K n . In each operating cycle, the separating device 4, 4' engages and separates the outermost warp thread of the group and presents it to a feed device 5, 5' which conveys the thread to a tying device 6. In this process, each of the two threads is gripped by a thread gripper (not shown) and the ends of the threads are then cut off by shears 7, 7' arranged between the feed devices 5, 5' and the tying device 6.
Since the tying machine 3 is not, as such, an object of the present invention, only those parts essential for an understanding of the invention have been shown in FIG. 1. A tying machine 3 of the type described is known and is marketed by the assignee hereof under the name USTER TOPMATIC.
Two thread guides 8, 9 on which the threads of the two groups K a , K n lie are arranged one on each side of the separating devices 4, 4'. The distance between these thread guides is relatively small, amounting to only a few millimeters. In the rest position, the threads assume the position shown in broken lines between the thread guides 8, 9 while the separating devices 4, 4' are arranged so that in each case the end of the thread guide facing its group of threads is arranged above the group of threads K a or, respectively, below the lower group of threads K n . To separate the outermost warp thread, the upper separating device 4 is moved downward and the lower separating device 4' is moved upward. By means of a notch arranged at its end face of the separating device 4, 4' and adjusted to the diameter of the thread, the separating device 4, 4' only takes hold of the one outermost warp thread and pushes it downward or upward out of the plane of the group of threads K a , K n from which it was taken, i.e., the warp thread plane.
As the outermost warp threads are moved out of the plane of their group of threads, they are deflected over the contact surfaces of the guide 8, 9 and act on the contact surfaces of the separating device to exert on them a force which is greater than that exerted by the outmost warp thread at rest (shown in broken lines) owing to the increasing thread tension (Hookes law).
This force varies according to whether the two or more warp threads are deflected about the contact surface of the respective thread guide. Experiments with threads of different yarn counts have shown that the force acting on the contact surface is twice as great when two threads are deflected simultaneously and three times as great when three threads are deflected as that exerted when only one thread is deflected.
Normally, only one outermost warp thread is separated at a time. The separation of two threads, a so-called double thread, results in formation of a three-legged knot, which should be avoided at all costs. The separation of a double thread should therefore be indicated before the tying process takes place.
In the tying machine 3 illustrated in FIG. 1, the above-mentioned dependence of the force acting on the point of deflection and on the separating device upon the number of deflected threads is used for monitoring and detecting the presence of double threads. Briefly, the detection is accomplished with a fault detecting means which senses a value related to the magnitude of the force exerted by said separating means in each of the successive thread deflecting operations. The fault detecting means produces an error signal when the sensed value does not correspond to a predetermined force which is essentially the approximate force required for deflecting a single thread.
The fault detecting means includes a displaceable guide means which supports the thread which has been separated from the group of warp threads. The guide means is movable in response to deflection of the separated thread from the warp thread plane. In addition, the fault detecting means includes a sensing means which detects movement of at least a portion of the guide means and generates a signal value which is related to the force applied to the thread that is separated by the separating means.
The monitoring may be carried out by means of sensing means such as sensors 10, 10', one being installed in each of the two thread guides 8, 9 for the two groups of threads K a , K n . FIG. 1 shows the sensors 10, 10' arranged on the thread guide 8 facing the free ends of the threads, with the sensor 10 placed on the upper group of threads K a and the sensor 10' placed on the lower group of threads K n . It should be noted, however, that the sensors 10, 10' could equally well be placed on the thread guide 9 facing the tying device 6 or they could even be placed one on each of the two thread guides 8, 9. Furthermore, the sensors 10, 10' could be arranged on the separating devices 4, 4', for example where the separating devices are mounted.
The sensors 10, 10' could in principle be any measuring elements suitable for indicating the forces acting on the deflecting points of the thread guides 8, 9. Piezoelectric convertors and elongation measuring strips (i.e., strain gauges) have proved to be particularly suitable.
The measuring signal of the sensors 10, 10' is transmitted to a control means having an amplifier 11, an evaluating stage 12, and a control unit 13. The amplifier 11 amplifies the measuring signal and transmits it to the control unit 13 of the tying machine 3 by way of the evaluating stage 12. The evaluating stage 12 is a suitable conventional comparator which compares the amplified signal to a predetermined threhsold value related to the force exerted by a single thread. In addition, the evaluating stage 12 sends appropriate signals to the control unit 13 for operating visual indicators and a switching device. The control unit 13 includes, inter alia, a means for interrputing or controlling operation of the machine, such as a switch 14 that is capable of switching off the drive 15 of the tying machine 3. The control unit further includes two double thread visual indicators 16, 16', one for the upper and one for the lower group of threads K a , K n . If, for example, the sensor 10 for the upper group of threads K a detects that the thread separated by the separating device 4 exerts a higher force on the thread guide 8, corresponding to the presence of a double thread, then the measuring signal obtained after amplification in the amplifier 11 acts on the switch 14 to stop the tying machine 3 and to turn on the double thread visual indicator 16 to produce a visual signal. The indicator 16 signals the presence of a double thread in the upper group of threads K a . The other indicator 16' signals the presence of a double thread in the lower group of threads K n .
The evaluating stage 12 is designed to be automatically calibrated for the contact force of an individual thread of the given group of threads as a predetermined reference value or threshold value, since the contact force depends on characteristics of the particular thread such as the yarn count, the material of the thread and the tension between the gripper rails 1, 2 and 1', 2'. It is also possible to regulate the warp thread tension between the gripper rails to a given value on the basis of the contact force.
The thread guides 8, 9 indicated schematically in FIG. 1 may in practice be in the form of flat plates, for example, and extend perpendicularly to the plane of the drawing. The groups of threads K a , K n lie on the part of these guides which is situated to the front with respect to the observer. As soon as one of the separating devices 4, 4' has gripped an outermost warp thread and pushed it out of the plane of its group of threads to present it to its corresponding feed device 5, 5', the separating device and outermost warp thread move perpendicularly to the plane of the drawing and the outermost warp thread slides on its thread guides 8, 9 to reach the portion of the thread guide 8 on which the sensors 10, 10' are situated. In this location, measurement of the contact force then takes place.
According to FIG. 2, the contact part of the thread guide 8 includes a rigid part or element 17 and a rocking part or element 18 displaceably mounted on the rigid part 17. The rocking part 18 is unilaterally attached to the rigid part 17 by a leaf spring 19. According to the drawing, the group of warp threads K a lies on the lefthand part of the rigid part 17 and on the adjacent area of the rocking part 18, which is the part of the tread guide 8 facing the observer in FIG. 1. When the separating device 4 (see FIG. 3) is moved downward in the direction of the arrow A, it separates the outermost warp thread K r and deflects it out of the plane of the group of threads K a . The separating device 4 is then displaced to the right in the direction of the arrow B and pulls the separated outermost warp thread K r away from its group of threads K a over the rocking part 18 and the separated thread then slides along this rocking part 18. The warp threads are prevented from slipping into the gap between the rigid part 17 and the rocking part 18 by means of lateral guides (not shown) arranged in this region.
The contact force is measured in the region of a measuring point M which, for the sake of making use of the force of leverage, is situated on the rigid part 17 at some distance from the point of attachment of the leaf spring 19. The leaf spring 19 has an elongation measuring strip 20 on each of the two surfaces which are the upper and the lower surfaces with respect to the direction of the contact force of the outermost warp thread K r and each of these strips 20 has a connection 21 for a cable leading to the amplifier 11 (FIG. 1). Instead of the elongation measuring strips 20, a piezoelectric sensor sensitive to deflection may be used.
In the example illustrated in FIGS. 2 and 3, the contact force exerted by the outermost warp thread K r is measured by means of the elongation of the elongation measuring strip 20 mounted on the leaf spring 19. A much more powerful measuring signal is obtained by measuring the deflection of the rocking part 18, i.e., by arranging the elongation measuring strip between the rocking part 18 and the rigid part 17 of the thread guide 8. Such an arrangement is illustrated in FIG. 4.
According to FIG. 4, the rocking part 18' may be a tongue extending away from the rigid part 17' of the thread guide 8. An L-shaped link plate 22 is attached in the region of the free end of the tongue, the lower arm of this link plate 22 extending under the top edge of the rigid part 17' in this region. The lower end of an elongation measuring strip 20' is clamped to the lower arm of this link plate 22 while the upper end of the strip 20' is fixed to the rigid part 17'. The elongation measuring strip 20' is either arranged between the rigid part 17' and the rocking part 18' without a special support or, as indicated in FIG. 4, it is applied to a small plate 23 of elastic plastic, preferably by being cast into this plate. Calculation shows that this measuring arrangement may be expected to produce a measuring signal which is about 20 to 30 times as great as that obtained from the arrangement of FIGS. 2 and 3. Practical experiments have shown that deflection of the rocking part 18' by 10 -5 mm. produces an elongation of the elongation measuring strip 20' of 10 -3 mm/m, which corresponds to about 35 times the measuring signal obtained with the arrangement of FIGS. 2 and 3.
According to another variation of the method (see FIG. 5) of measuring the force of contact of the outermost warp thread, a piezoelectric convertor 24 is used for this measurement instead of an elongation measuring strip. For this purpose, a suitable deflecting element 25 for the outermost warp thread is arranged laterally to the thread guide 8 to extend slightly beyond the contact surface of the thread guide. Such a deflecting element 25 may be, for example, stirrup-shaped or flat, and is mounted on a supporting shaft 26 which makes contact with the piezoelectric convertor 24. When the separated outermost warp thread K r is moved away from its group of threads K a , it is pushed on this deflecting element 25 and the force of contact which it exerts on this element produces a force acting on the piezoelectric convertor 24 in the longitudinal direction of the supporting shaft 26.
Other embodiments of the monitoring device described are conceivable and lie within the competence of a person of ordinary skill in the art. In such additional embodiments, the presence of double threads should be monitored by means of the force of contact of a separated outermost warp thread on its respective guide or point of deflection or on the separating device.
It will now be apparent that the present invention provides a novel device for determining the presence of double threads. Moreover, it will be apparent to those skilled in the art that there are numerous modifications, variations, substitutions and equivalents for the features of this invention which do not materially depart from the scope of the invention. Accordingly, it is expressly intended that all such modifications, variations, substitutions and equivalents that fall within the spirit and scope of the appended claims be embraced thereby.
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A tying machine includes a tying device, grippers for two groups of warp threads (K a , K n ) which are to be tied together and a device for separating the outermost warp thread of each group and moving it out of the plane of the warp. In the region between the separating device and a gripper, the warp threads are guided over a thread guide where the outermost warp thread is deflected and moved out of the plane of the warp. A measuring device for measuring the force exerted by a deflected warp thread on the point of deflection or on the separating device is arranged in the region of deflection, and the signal of this measuring device serves as criterion for the presence of a double thread. The measuring device may be a piezoelectric pressure convertor or an elongation measuring strip or a piezo sensor which is sensitive to deflection. Thus, the measuring device is virtually unaffected by dirt or dust. Since the signal produced by a double thread is twice as great as that produced by a single thread, such double threads are reliably recognized.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to German Patent Application No. 10 2009 020 840.2, filed May 12, 2009, which is hereby incorporated by reference in its entirety for all purposes.
TECHNICAL FIELD
The present disclosure relates to an aircraft high lift system with at least one load station for actuating a flap of a wing, preferably a landing flap and/or a leading-edge flap, and at least one transmission with transmission portions located between branch transmissions, wherein by means of the branch transmissions actuating energy can be branched off from the transmission to the load station, and to a method for determining an operating condition of an aircraft high lift system.
BACKGROUND AND SUMMARY
Aircraft high lift systems which actuate and move wing flaps such as landing flaps and leading-edge flaps of the aircraft can get into inadmissible operating conditions or error conditions. For safety reasons, it is necessary to immediately detect these inadmissible operating conditions and preferably communicate the same directly to the pilot.
Inadmissible operating conditions can result for example from
an interruption of a load path of a drive station of a wing flap (“disconnect”), an interruption in the transmission of the aircraft high lift system, a jamming of elements of a load path of a drive station (“jam”), a jamming in the transmission and/or a skewing of a flap body (“skew”).
To avoid for example inadmissible loads in the jamming case (“jam”), aircraft high lift systems known from the prior art, as schematically shown in FIG. 1 , employ mechanical torque limiters 18 .
From DE 103 08 301 B3, an aircraft high lift system with an overload protection is known, which includes a drive system and elements for transmitting the drive energy over the entire wing span to drive stations of individual segments of landing flap/leading-edge flap systems. The overload protection consists of force sensors such as strain gauges and/or load cells arranged at the outlet of the respective drive station or of the actuating gears for the landing flaps or leading-edge flaps. Jamming cases in the actuating gear and/or in the transmission are, however, not detectable with this system.
The US 2006/0060719 A1 relates to an aircraft high lift system with a drive unit, elements for transmitting the drive energy to drive stations of individual segments of landing flap/leading-edge flap systems and with an overload protection, wherein the overload protection includes at least one electrical overload sensor which is arranged in the drive train between the drive unit and an output station.
All known systems have in common that an interruption of the load path merely is detected indirectly via the response of a torque limiter or by means of the resulting obvious skewing of a flap. Depending on the design of the structural components and the drive and guiding elements, the error can also remain unnoticed up to the next maintenance interval.
Furthermore, in the known aircraft high lift systems with mechanical torque limiter a localization of the error location generally can only be effected by visual inspection of the mechanical indications on the load limiters.
It would be desirable, however, to provide for a direct localization of the error location.
Therefore, it is the object of the present disclosure to develop an aircraft high lift system as mentioned above in an advantageous way, in particular to the effect that the same is of simpler and lighter construction due to the omission of heavy and complex components and provides for a localization of the error location independent of where the error is located in the system, i.e. also provides for detecting errors in the actuating gear and/or in the transmission.
In accordance with the present disclosure, this object is solved by an aircraft high lift system with at least one load station for actuating a flap of a wing, for example a landing flap and/or a leading-edge flap, and at least one transmission with transmission portions, which are disposed between branch transmissions, wherein by means of the branch transmissions, actuating energy can be branched off from the transmission to the load station, wherein at least one detection sensor is provided, by which an operating condition of the transmission and/or the load station can directly and/or indirectly be determined, wherein the detection means on the output side of the branch transmission is arranged in the inlet of the load station and/or in a transmission portion. Accordingly, it is provided that an aircraft high lift system includes at least one load station for actuating a wing flap, for example a landing flap and/or a leading-edge flap, and at least one transmission with transmission portions located between branch transmissions, wherein by means of the branch transmissions actuating energy can be branched off from the transmission to the load station. At least one detection means is provided, by means of which the operating condition of the transmission and/or the load station can directly and/or indirectly be determined, wherein the detection means on the output side of the branch transmission is arranged in the inlet of the load station and/or in a transmission portion.
This provides the advantage that a simple construction of the aircraft high lift system becomes possible. At the same time, a localization of a possible error is facilitated, since by assigning the signal to the detection means, whose arrangement in turn is known, the error location within the system is easily communicated. Furthermore, it is particularly advantageous that the error and also the error location can directly be communicated to the pilot.
Furthermore, it can be provided that by means of the detection means the torque applied and/or the time course of the torque can be detected and/or that the detection means is a torque sensor. This provides the advantage that the easily evaluatable characteristic of the torque or torque profile can be utilized for determining the operating condition and correspondingly also for faulty operating conditions. In the aircraft high lift system, reference values and/or curves or patterns for example can be stored in suitable means, which can be matched with current values. By such indirect evaluation, detailed conclusions as to the operating condition can already be made possible with a small number of detection means. Moreover, by means of the reference values and/or curves or patterns a detailed statement as to the kind of error and the error location in one and/or both of the load stations of a flap can already be made possible with only one single detection means.
It is furthermore conceivable that no mechanical torque limiter is present, in particular that no mechanical torque limiter is present on the output side of a transfer gear in the transmission branching off actuating energy provided by a central drive unit and/or that no mechanical torque limiter is present in a load station. This provides the advantage that the aircraft high lift system can be constructed simpler and lighter in weight. Due to the omission of the highly complex and heavy components, the prime costs, but also the maintenance costs are decreased, since the maintenance requirements can be reduced in addition.
Moreover, it is conceivable that an evaluation unit is provided, which has a signal connection with the at least one detection means and by means of which the signals of the detection means can be evaluated, in order to determine an operating condition. Advantageously, reference values and/or curves or patterns with respect to correct operating conditions and faulty operating conditions are stored in the evaluation unit or can be retrieved by the evaluation unit. It is furthermore conceivable that the evaluation unit logs its determination results and stores the same in a memory. Furthermore, the evaluation unit can communicate the current operating conditions to the pilot and also possibly issue warnings in the case of faulty operating conditions via an output unit such as a monitor or a control instrument in the cockpit.
Furthermore, it can be provided that the evaluation unit is a central evaluation unit which has a signal connection with all detection means of the aircraft high lift system. Thus, the information from the detection means of the left and right wing advantageously can be evaluated together in the central evaluation unit.
It is furthermore possible that a load station includes a station actuator and a spindle with a spindle nut, wherein the station actuator transmits the actuating torque to the spindle and the spindle nut converts the rotatory movement into a translational movement for the flap, and that the detection means in the load station is arranged before the station actuator.
It can also be provided that the transmission portion is a transmission portion between the branch transmissions of two load stations associated to a flap.
It is furthermore conceivable that by means of the detection means arranged in this transmission portion the torque applied there and/or the time course of the torque can be determined.
It can advantageously be provided that by monitoring the ratio of the load components of the load stations faulty operating conditions can be determined by means of the evaluation unit and/or that by monitoring and comparing pairs of the actuating forces applied at the load stations of the left and right wing of the aircraft faulty operating conditions can be determined by means of the evaluation unit and/or that by including the current values for wing configuration, the aircraft weight, the airspeed and/or the temperature a desired value for the actuating force applied at the load stations can be determined by means of the evaluation unit, and that by matching the actual values determined with the calculated desired values faulty operating conditions can be determined by means of the evaluation unit.
In particular, it is advantageous when by direct and/or indirect comparison of the load components of two load stations
a jamming case in one of the load stations of two load stations associated to a flap can be determined by means of a rising operating torque in the first load station associated to the flap with constant operating torque of the second load station associated to the flap and/or an interruption of a load path in a first load station associated to a flap can be determined by means of the presence of the entire load on the intact load path of the second load station associated to the flap and/or a skewing of the flap after an interruption or a jump in the time course of the applied torque in a load station associated to the flap can be determined and/or an interruption in the transmission portion between the flaps can be determined by means of a torque decrease at both load stations by using at least one signal from position measuring means for determining the flap position and/or an interruption of the transmission portion between the load stations of the outer flap can be determined by means of the reaction of the inner load station and/or an interruption of the transmission portion between the load stations of the inner flap can be determined by means of a change in the ratios of the load components of the load stations of the inner and outer flap by using the evaluation unit.
Furthermore, the present disclosure relates to a method for determining an operating condition of an aircraft high lift system with at least one load station for actuating a flap of a wing, preferably a landing flap and/or leading-edge flap, and at least one transmission for transmitting actuating energy to the load stations, wherein with reference to the torque applied at the transmission and/or in the load station and/or the time course of the torque the operating condition of the aircraft high lift system is determined directly and/or indirectly. Accordingly, it is provided that in a method for determining an operating condition of an aircraft high lift system with at least one load station for actuating a wing flap, preferably landing flap and/or leading-edge flap, and at least one transmission for transmitting actuating energy to the load stations by means of the torque applied at the transmission and/or in the load station and/or the time course of the torque the operating condition of the aircraft high lift system is directly and/or indirectly determined.
Furthermore, it is conceivable that by monitoring and comparing pairs of the actuating forces applied at the load stations of the left and right wing of the aircraft faulty operating conditions are determined and/or that by including the current values for wing configuration, the aircraft weight, the airspeed and/or the temperature a desired value for the actuating force applied at the load stations is determined, and that by matching the actual values determined with the calculated desired values faulty operating conditions are determined.
In addition, it can be provided that by monitoring the ratio of the load components of the load stations faulty operating conditions are determined.
Furthermore it is possible that by direct and/or indirect comparison of the load components of two load stations
a jamming case in one of the load stations of two load stations associated to a flap is determined by means of a rising operating torque in the first load station associated to the flap with constant operating torque of the second load station associated to the flap and/or an interruption of a load path in a first load station associated to a flap is determined by means of the presence of the entire load on the intact load path of the second load station associated to the flap and/or a skewing of the flap after an interruption or a jump in the time course of the applied torque in a load station associated to the flap is determined and/or an interruption in the transmission portion between the flaps is determined by means of a torque decrease at both load stations by using at least one signal from position measuring means for determining the flap position and/or an interruption of the transmission portion between the load stations of the outer flap is determined by means of the reaction of the inner load station and/or an interruption of the transmission portion between the load stations of the inner flap is determined by means of a change in the ratios of the load components of the load stations of the inner and outer flap.
Advantageously, the method is performed with the aircraft high lift system described herein.
Further details and advantages of the present disclosure will now be explained in detail with reference to an embodiment illustrated in the drawing.
BRIEF DESCRIPTION OF FIGURES
FIG. 1 shows a known aircraft high lift system in a schematic representation.
FIG. 2 shows an aircraft high lift system of the present disclosure in a schematic representation in a first embodiment.
FIG. 3 shows an aircraft high lift system of the present disclosure in a schematic representation in a second embodiment.
DETAILED DESCRIPTION
FIG. 1 shows a known aircraft high lift system 10 in a schematic representation. The aircraft high lift system 10 includes a central drive unit 12 , by means of which electric or hydraulic energy of the aircraft supply is converted into mechanical actuating energy. By means of non-illustrated braking means, the aircraft high lift system can be maintained in position.
Via a central shaft 14 , the central drive unit 12 transmits the actuating energy from the central drive unit 12 to a transfer gear 16 , which distributes the actuating energy to the transmission 17 of the right wing and to the transmission 17 ′ of the left wing. In the embodiment shown in FIG. 1 , the construction of the aircraft high lift system substantially is only shown for the right wing.
On the output side of the transfer gear 16 , a torque limiter 18 , 18 ′ is each provided, which on overload blocks the drive and dissipates the actuating torque into the non-illustrated supporting structure, in particular into the supporting structure of the transmission 17 in the fuselage and/or wing.
On the output side of the torque limiter 18 , branch transmissions 40 a , 40 b , 40 c , 40 d are arranged in the transmission 17 , which preferably are identical in construction. The branch transmissions 40 a and 40 b are associated to the right-hand inner landing flap 20 and the branch transmissions 40 c and 40 d are associated to the right-hand outer landing flap 30 .
To each landing flap 20 and 30 , two substantially preferably identically constructed load stations 22 , 24 , 32 , 34 are associated. In detail, the load stations 22 and 24 are associated to the right-hand inner landing flap 20 and the load stations 32 and 34 are associated to the right-hand outer landing flap 30 . The branch transmissions 40 a , 40 b , 40 c , 40 d each withdraw the required actuating energy for the load stations 22 , 24 , 32 , 34 associated to the respective branch transmission 40 a , 40 b , 40 c , 40 d from the transmission 17 .
Between the branch transmissions 40 a and 40 b a first transmission portion 42 is disposed, between the branch transmissions 40 b and 40 c a second transmission portion 44 is disposed, and between the branch transmissions 40 c and 40 d a third transmission portion 46 is disposed. The first and third transmission portions 42 and 46 are portions of the transmission 17 , which are located between the branch transmissions 40 a and 40 b or 40 c and 40 d , respectively, which each are associated to a landing flap 20 , 30 .
The transmission portions 42 , 44 , 46 of the transmission 17 preferably, in particular for safety reasons, are configured and arranged uncoupled such that each load station 22 , 24 , 32 , 34 can each be supplied with actuating energy independent of the condition of the remaining load stations.
After the branch transmission 40 a , 40 b , 40 c , 40 d a station torque limiter 50 a , 50 b , 50 c , 50 d is provided, which in a case of error limits the actuating torque transmitted and thus can prevent damages at the load station. On the output side of the station torque limiters 50 a , 50 b , 50 c , 50 d a station actuator 60 a , 60 b , 60 c , 60 d is provided, which converts the actuating torque and transmits the same to the spindle 70 a , 70 b , 70 c , 70 d.
The spindle 70 a , 70 b , 70 c , 70 d transmits the actuating energy to the spindle nut 80 a , 80 b , 80 c , 80 d , which in turn converts the rotatory movement transmitted to the same into a translational movement. Via the guide transmissions 90 a , 90 b , 90 c , 90 d , this translational movement or the actuating energy transmitted thereby is each forwarded to the flaps 20 and 30 and the kinematic course of the flap movement is determined.
In FIGS. 2 and 3 , a first and a second embodiment for an aircraft high lift system in accordance with the present disclosure are shown. Comparable components are provided with the same reference numerals from FIG. 1 .
In the embodiment of an aircraft high lift system 10 of the present disclosure as shown in FIG. 2 and in FIG. 3 , the station torque limiters 50 a , 50 b , 50 c , 50 d and the system torque limiter 18 present in the aircraft high lift system 10 shown in FIG. 1 are missing.
In the embodiment of FIG. 2 , detection means 110 a , 110 b , 110 c , 110 d configured as detection sensors, such as load sensors or torque sensors 110 a , 110 b , 110 c , 110 d each are arranged on the output side of the branch transmissions 40 a , 40 b , 40 c , 40 d and before the station actuators 60 a , 60 b , 60 c , 60 d or transmissions 60 a , 60 b , 60 c , 60 d on the input shaft of the respective load station 22 , 24 , 32 , 34 .
By means of the load sensors or torque sensors 110 a , 110 b , 110 c , 110 d the torque applied and hence also the actual torque profile can be detected. Corresponding signals are forwarded to the electronic evaluation unit 100 via the signal lines 102 . Signal lines 102 ′ lead to the non-illustrated left wing. Evaluation unit may include code and instructions on computer readable storage medium for carrying out the various method actions described herein.
In the embodiment shown in FIG. 3 , load sensors 110 ′ and 110 ″ each are provided between individual load stations 22 , 24 or 32 , 34 of the flaps 20 , 30 , which have a signal connection with the evaluation unit 100 via signal lines 102 .
The load sensor 110 ′ associated to the right-hand inner flap 20 is arranged on the transmission shaft 42 or the transmission portion 42 between the load stations 22 and 24 , whereas the load sensor 110 ″ associated to the right-hand outer flap 30 is arranged on the transmission shaft 46 or the transmission portion 46 between the load stations 32 and 34 .
Thus, advantageously, only one sensor 110 ′ or 110 ″ per flap 20 , 30 is required, so that the number of required sensors 110 ′, 110 ″ for an aircraft high lift system 10 advantageously can be halved as compared to previously known systems. In principle, however, for example one or more additional sensors can be provided for reasons of redundancy.
All methods for error detection described with reference to FIG. 2 correspondingly can also be used with the aircraft high lift system shown in FIG. 3 , in particular be performed by means of the evaluation unit 100 , and in the two systems shown in FIGS. 2 and 3 rotary actuators can also be used instead of the spindles 70 a , 70 b , 70 c , 70 d.
In error-free operation, each load station 22 , 24 , 32 , 34 transmits a certain amount of the wind load acting on the flap 20 , 30 . This load component is specified by the geometry of the flap 20 , 30 and the aerodynamic load distribution and is only changed in a case of error. In consideration of these circumstances, a possibility for error detection is given by monitoring the ratio of the load components of the load stations 22 , 24 , 32 , 34 or components thereof associated to a flap 20 , 30 . For monitoring the load components of the load stations 22 , 24 , 32 , 34 or components thereof associated to a flap 20 , 30 , the procedure can be as follows:
Upon occurrence of a jamming case in a load station 22 , 24 , 32 , 34 , also referred to as “jam”, the operating torque of the defective load station 22 , 24 , 32 , 34 will rise comparatively strongly, whereas the load component of the intact load path does not change. Thus, the occurrence of a jamming case can be detected unambiguously by means of the evaluation unit 100 . In the case of an interruption of the load path within a first load station, also referred to as “disconnect”, for example with the right-hand inner flap 20 the load station 22 , no more load is transmitted along this path, whereas the intact load path, for example with the right-hand inner flap 20 the load station 24 , must now bear the entire load. Thus, the occurrence of this error case can be detected unambiguously by means of the evaluation unit 100 . In the embodiment shown in FIG. 2 , this is directly detectable by means of the signal of the load sensors 110 a , 110 b , 110 c , 110 d . In the embodiment shown in FIG. 3 , this error case can be detected indirectly via the changed time course e.g. of the torque in particular within the transmission portions 42 and 46 , which can be detected by the evaluation unit 100 for example by matching against reference curves. The error case “skewing of a flap”, also referred to as “skew”, only occurs after an interruption of the load path and hence can also be detected by the evaluation unit 100 . By means of the evaluation unit 100 and the load sensors 110 a , 110 b , 110 c , 110 d and 110 ′, 110 ″, respectively, the time course of the torque in a load station 22 , 24 , 32 , 34 can be monitored, so that an interruption of the load path is directly detected. In the embodiment shown in FIG. 2 , this is directly detectable by means of the signal of the load sensors 110 a , 110 b , 110 c , 110 d . In the embodiment shown in FIG. 3 , this error case can be detected indirectly via the changed time course e.g. of the torque in particular within the transmission portions 42 and 46 , which can be detected by the evaluation unit 100 for example by matching against reference curves. In the case of an interruption of the transmission in the transmission portion 44 between the flaps 20 and 30 , the flap 20 or 30 separated from the drive is set back by the wind load. Both torque sensors 110 a and 110 b or 110 c and 110 d according to the embodiment shown in FIG. 2 no longer measure any load. In the embodiment shown in FIG. 3 , the load sensor 110 ′ and/or 110 ″ associated to the flap 20 or 30 separated from the drive no longer measures any load. This error case can e.g. be detected by non-illustrated position sensors, which preferably are connected with the evaluation unit 100 . Alternatively or in addition, the procedure can be as follows: An interruption of the transmission 17 between the actuators of the outer flap, e.g. in the transmission portion 44 and/or 46 , is detected like an interruption of the load path (see above), because the flap loads only are reacted to by the load stations 22 , 24 of the inner flap 20 . An interruption of the transmission between the actuators of the inner flap 20 in the portion 42 likewise is unambiguously detected by the evaluation unit 100 , because in this error case the load portion of the outer flap 30 is transmitted by the actuators of the inner flap 20 to the flap structure, which in this case serves as second load path. In this condition, the entire drive power of the half wing passes over the inner actuator 22 of the inner flap 20 , whereas the outer actuator 24 of the inner flap 20 only supports the transmission of the outer flap 30 . The ratio of the actuator loads hence clearly is changed and hence can unambiguously be associated to this error case.
In particular, it is advantageous that by means of the sensors 110 a , 110 b , 110 c , 110 d and 110 ′, 110 ″, respectively, and by means of the signal transmitted by them the error location is also detected at the same time. An expensive search by the maintenance personnel hence can be omitted.
A jamming case in the transmission 17 can be detected for example by non-illustrated overload protection devices, in which e.g. sensors monitor the torque applied in the transmission.
For monitoring the loads of the load stations 22 , 24 , 32 , 34 of the right and left wing, the procedure furthermore can be as follows:
With an undisturbed straight flight, the wind loads at the flaps 20 , 30 of the right and left wing are the same. Since the drive systems of the flaps 20 , 30 are axially symmetrical to the longitudinal axis of the aircraft, equal actuating forces are produced at the load stations to the left and right at equal positions, which are detected by the load sensors and are compared in pairs in an electronic evaluation unit. With reference to these criteria, it can additionally be detected by means of the evaluation unit 100 whether an interruption of the load path of a drive station or load station 22 , 24 , 32 , 34 , an interruption in the transmission 17 , 17 ′, a jamming of elements of the load path of a drive station, a jamming in the transmission 17 , 17 ′ and/or a skewing of a flap body 20 , 30 has occurred.
It is provided to consider influences acting on the flaps 20 , 30 of the right and left wing, which cause an unsymmetrical loading of the flaps 20 , 30 . These influences in particular include the unilateral use of a spoiler such as a roll spoiler, but also the influence of gusts, sideslip, turning flight, side wind or entry into turbulent wakes e.g. of an aircraft flying ahead. These influences generally are limited in time and can therefore be filtered out.
Furthermore, it is also possible to operate or support an error detection by means of a comparison of the desired and actual values of the loads:
For this purpose, a desired value for each load station 22 , 24 , 32 , 34 is calculated by means of the evaluation unit 100 from the values for the configuration of the wing such as the flap angle, the aircraft weight, the airspeed, the temperature etc. and compared with the actual value measured. In the case of significant deviations, which are detectable e.g. by means of corresponding limit values, one of the error cases described above is detected. To each error case one or more limit values are associated, and when the same are exceeded or not reached, an error case will be detected unambiguously on the part of the evaluation unit.
The structure of the left part of the aircraft high lift system 10 of the present disclosure substantially is identical in construction, as shown in FIGS. 2 and 3 . In principle, however, it is likewise conceivable to provide independent aircraft high lift systems 10 for the left and the right wing, as they are shown in FIG. 2 or 3 .
Furthermore, it is conceivable in principle to configure an aircraft high lift system 10 such that it is a combination of the systems shown in FIGS. 2 and 3 , i.e. includes both the torque sensors 110 a , 110 b , 110 c , 110 d and 110 ′, 110 ″ with the arrangements shown in FIGS. 2 and 3 .
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The present disclosure relates to an aircraft high lift system with at least one load station for actuating a flap of a wing, preferably a landing flap and/or a leading-edge flap, at least one transmission with transmission portions located between branch transmissions, wherein by means of the branch transmissions actuating energy can be branched off from the transmission to the load station, and to a method for determining an operating condition of an aircraft high lift system.
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FIELD OF THE INVENTION
[0001] The present device relates to an improvement to protective barriers that are commonly installed beneath ceilings and in place of walls in buildings that are under construction or being renovated to protect selected areas from dust and moisture created by or permitted to enter due to the work being performed.
BACKGROUND
[0002] Protective barriers, such as those described herein, are commonly used to prevent dust, debris and moisture from falling onto floors, people, merchandise and equipment located below ceilings or roofs being repaired or constructed. In this way, the protective barrier protects from added costs from damage or injury resulting from such falling material and encroaching moisture and can allow work to continue below the ceiling or roof under construction. Such barriers are commonly constructed from interconnected sections of polyethylene sheets or similar materials, which have proven to be durable, easy to work with, and relatively inexpensive.
[0003] However, a problem can arise with this type or protective barrier, which can allow some dust to pass through the barrier. Specifically, a protective barrier can comprise sections of polyethylene sheets or similar materials connected by seams which are typically made by sewing two or more sections together. The sewing of these seams results in thousands of holes created when a needle, used to sew the sections together, pierces the sections to allow the string to be threaded through them to bind them together. These holes create passageways through which dust and other powdery substances can travel, thus circumventing the purpose of the protective barrier.
[0004] What is needed is a protective barrier comprising sections connected by seams sewn together in a way that prevents dust from being able to pass through the holes created by the sewing.
SUMMARY OF THE INVENTION
[0005] It is an aspect of the present inventive concept to provide a seam for connecting sections of material, which can be configured to prevent dust from being able to pass through the holes created by the sewing together of two or more sections of polyethylene sheets or similar materials.
[0006] The above aspects can be obtained by a protective barrier comprising at least one first section and at least one second section connected by a seam where the first section and second section come into contact with each other, the seam also comprising a dustcover system comprising a first dustcover section and a second dustcover section, wherein each is connected to the first section and the second section, wherein the seam is at least partially covered by a part of the first dustcover section and a part of the second dustcover section; and a thread connecting the first dustcover section, the second dustcover section, the first section, and the second section, by passing through the first section, the second section, the first dustcover section and the second dustcover section.
[0007] The above aspects can also be obtained by a method for constructing a protective barrier, the method comprising: providing a protective barrier, comprising at least one first section and at least one second section, a dustcover system comprising a first dustcover section and a second dustcover section, and a thread; placing the first section and second section into contact with each other creating a seam; placing the first dustcover section and a second dustcover section over the seam; and using the thread to connect the first dustcover section, the second dustcover section, the first section, and the second section, by passing the thread through the first section, the second section, the first dustcover section and the second dustcover section so that the thread is covered by part of the first dustcover section and part the second dustcover section.
[0008] These together with other aspects and advantages which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part thereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Further features and advantages of the present device, as well as the structure and operation of various embodiments of the present device, will become apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:
[0010] FIG. 1 is a schematic drawing of a prior art seam connecting two sections of polyethylene sheets or similar materials to create a protective barrier;
[0011] FIG. 2 is a side, cutaway view of the schematic drawing of the prior art seam shown in FIG. 1 connecting two sections of polyethylene sheets or similar materials comprising the protective barrier through which a dust or similar powder is shown passing through the seam;
[0012] FIG. 3 is a schematic drawing of a seam connecting two sections of polyethylene sheets or similar materials comprising a protective barrier, wherein the seam comprises a dustcover system, according to an embodiment;
[0013] FIG. 4 is a side, cutaway view of the seam connecting two sections of polyethylene sheets or similar materials comprising a protective barrier, as shown in FIG. 3 , wherein the seam comprises a dustcover system, according to an embodiment;
[0014] FIG. 5 is an exploded view of the seam connecting two sections of polyethylene sheets or similar materials comprising the protective barrier as shown in FIGS. 3 and 4 , wherein the seam comprises a dustcover system, according to an embodiment;
[0015] FIG. 6 is a side, cutaway view of the seam connecting a first section and a second section comprising a protective barrier, each comprised of polyethylene sheets or similar materials, wherein the seam comprises a dustcover system, according to an alternative embodiment; and
[0016] FIG. 7 is an exploded view of the seam shown in FIG. 6 connecting the first section and second section comprising a protective barrier, wherein each is comprised of polyethylene or similar materials comprising a protective barrier, wherein the seam comprises a dustcover system, according to an alternative embodiment.
DETAILED DESCRIPTION
[0017] This description of the exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description, relative terms such as “lower,” “upper,” “horizontal,” “vertical,”, “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.
[0018] Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
[0019] The present dustcover system can be used to solve the problem created when two or more sections of polyethylene, or similar materials, are sewn together creating holes through each. Polymers, such as polyethylene, have many attractive features when used as protective barriers including the fact that they are impermeable to almost all types of liquids, powders and small debris including dust and water, and they are relatively inexpensive per square foot. However, a disadvantage of polymers, such as polyethylene, is that, unlike fabrics, holes created when a needle and thread are placed through them do not close or even get smaller over time. Rather, such holes stay the same size as when they were created or get larger and create passageways sufficiently large for dust and water to travel through thus reducing the effectiveness of the protective barrier. The present dustcover system can prevent dust from passing through these holes by covering them with dustcover sections, which are attached to the seam and can interlock over the seam in some embodiments. In some embodiments, these dustcover systems can completely cover the seams further inhibiting the flow of dust and water through the seam.
[0020] FIG. 1 is a schematic drawing of a protective barrier 100 comprising a seam 101 , which is part of the prior art, connecting a first section 102 of polyethylene sheet or similar material to a second section 103 of polyethylene sheet or similar material using a thread 104 , according to an embodiment. In this representational view of the prior art, holes 105 are created each time the thread 104 passes through the first section 102 and second section 103 to create the seam 101 .
[0021] FIG. 2 is a side, cutaway view of the seam 101 , which is part of the prior art, comprising the protective barrier 100 shown in FIG. 1 . In this view, the thread 104 comprising the seam 101 is shown connecting the first section 102 to the second section 103 and dust 106 is shown passing from an outer, unprotected side 107 of the protective barrier 100 to an inner, protected side 108 of the protective barrier 100 . This passage of dust can be prevented by the present apparatus, in its various embodiments, which are explained in detail below.
[0022] FIG. 3 is a schematic drawing of a seam 301 connecting a first section 302 to a second section 303 of a protective barrier 300 , wherein the seam 301 comprises a dustcover system 310 , according to an embodiment. This dustcover system 310 can be comprised of a first dustcover section 311 and a section dustcover section 312 . According to an embodiment, both the first dustcover section 311 and the second dustcover section 312 can be configured to fold over the seam 310 , thus preventing dust (not pictured in FIG. 3 ) from being allowed to pass through the holes 305 created by the thread 304 . Specifically, according to an embodiment, the dustcover sections 312 and 313 can be comprised of a polyethylene or similar material which can be made to retain a shape configured to bend over the seam 301 and stay in that position. In addition, the dustcover 310 can be configured so that it can be opened while the seam 301 is sewn and automatically close after the seam 301 has been sewn.
[0023] The thread 304 , comprising a protective barrier 300 , can be made from any standard material used to create thread, including nylon, cotton, silk, polypropylene, polyester and any number of other natural or synthetic materials, which are commonly used to manufacture thread. However, in an embodiment the thread 304 can be comprised of a water soluble material such as polyvinyl alcohol, which can disintegrate when contacted by water allowing the seam 301 to come apart. The benefits of protective barriers comprising such seems have been described in U.S. patent application Ser. No. 13/964,968, which is incorporated by reference herein in its entirety. Similarly, in an alternative embodiment the thread 304 can be comprised of a heat sensitive material such as a copolyamide or polycprolacone, which can disintegrate when subjected to temperatures between 140 degrees and 180 degrees Celsius allowing the seam 301 to come apart at those temperatures. The benefits of protective barriers comprising such seems have been described in U.S. patent application Ser. No. 13/965,137, which is also incorporated by reference herein in its entirety.
[0024] FIG. 4 is a side, cutaway view of the protective barrier 300 , as shown in FIG. 3 , comprising a seam 301 connecting a first section 302 to a second section 303 , wherein the seam comprises a dustcover system 310 , according to an embodiment. In this figure, the shape of the first dustcover section 311 and the shape of the second dustcover section 312 can each be seen clearly. Specifically, each dustcover section is shown to be a C-shape, wherein each is facing in an opposite direction, according to an embodiment, but this folded-over configuration could also be described as a V-shape or U-shape. As shown, the seam 301 comprises, in order from bottom to top, the thread 304 , having a bottom section 314 , the second section 303 , followed by the first end 322 of the second dustcover section 312 , the first section 302 , followed by the first end 321 of the first dustcover section 311 , and the top section 324 of the thread 304 . All of these components are bound together by the thread 304 . Above the top section 324 of the thread 304 of a polyethylene or similar material, can be the second end 331 of the first dustcover section 311 , which can be made to retain a C-shape configured to bend over the seam 301 and stay in that position. In an embodiment, the first dustcover section 311 can have a C-shape with an opening to the right and the second dustcover section 312 can have a C-shape with an opening to the left. Above the second end 331 of the first dustcover section 311 can be the second end 332 of the second dustcover section 312 , which can also bend over the top section 324 of the thread 304 and bend over the second end 331 of the first dustcover section 311 . As shown in FIGS. 3 and 4 , the thread 304 and the holes 305 , shown in FIG. 3 , can be covered by the two second ends of the dust cover sections, 331 and 332 , comprising the dustcover system 310 . The primary advantage of this system 310 is that the second end 331 of the first dustcover section 311 and the second end 332 of the second dustcover section 312 are not punctured by the thread 304 , but can still open sufficiently to allow the thread 304 to be installed beneath them. Once the second end 331 of the first dustcover section 311 and the second end 332 of the second dustcover section 312 are in place, as shown in FIGS. 3 and 4 , there are no holes available for dust to pass through the protective barrier 300 .
[0025] FIG. 5 is an exploded view of the seam 301 connecting two sections, 302 and 303 , of polyethylene sheets or similar materials comprising a protective barrier 300 , previously shown in FIGS. 3 and 4 , wherein the seam 301 comprises a first dustcover section 311 and a second dustcover section 312 , according to an embodiment. In this embodiment the first dustcover section 311 is adjacent to the first section 302 and the second dustcover section 312 is adjacent to the second section 303 .
[0026] FIG. 6 is a side, cutaway view of the seam 601 connecting a first section 602 and a second section 603 comprising a protective barrier 600 . Each can be comprised of polyethylene sheets or similar materials comprising a protective barrier, wherein the seam 601 comprises a first dustcover section 611 and a second dustcover section 612 , according to an alternative embodiment. In this embodiment, the dustcover 605 can be comprised of the first dustcover section 611 and second dustcover section 612 , which are the same as in the embodiment shown in FIGS. 3 thru 5 . However, in this embodiment, the first dustcover section 611 and second dustcover section 612 , are located above the point where the first section 602 and the second section 603 come into contact with each other. This alternative configuration can provide the same protection to the seam 601 as that provided by the dustcover system 310 to seam 301 in the embodiment described and shown in FIGS. 3-5 .
[0027] FIG. 7 is an exploded view of the seam 601 connecting a first section 602 and a second section 603 , each comprised of polyethylene sheets or similar materials, comprising a protective barrier 600 , wherein the seam 601 comprises a first dustcover section 611 and a second dustcover section 612 , according to an alternative embodiment. This view shows how the first section 602 is directly connected to the second section 603 according to this embodiment. Further, this view also shows how the first dustcover section 611 can be located partially within the second dustcover section 612 , thus protecting and covering the thread 624 wherein both are located above the first section 602 and the second section 603 .
[0028] Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention.
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The present protective barrier is similar to those commonly installed beneath ceilings during construction work being performed on ceilings or roofs of buildings, wherein two or more sections are sewn together to construct the protective barrier. However, the present protective barrier also comprises a dustcover, which covers the seam entirely preventing dust from passing through holes created when the seam is sewn using a thread or similar means.
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FIELD OF THE INVENTION
This invention relates generally to plastic sheet sealing and dividing means, and is more particularly concerned with a method and apparatus for dividing a single large tubular member into a plurality of smaller tubular members, commonly known as slit sealing.
BACKGROUND OF THE INVENTION
It is very common in the plastics industry to produce a film of plastic, for example polyethylene, by extruding the plastic material in a tubular shape. In order to achieve the greatest efficiency, the extruders have been made increasingly larger so that the diameter of the extruded tube is quite large. A common means for utilizing these extruded tubular members is to subdivide the large tubular member by flattening the tubular member between pinch rolls, severing the tube longitudinally thereof, and sealing the cut edges to provide a plurality of tubular members. These smaller tubular members can then be cut and sealed transversely to provide a plurality of bags of a reasonably useable size.
The conventional means for carrying out the slitting and sealing operation is through the use of a knife arrangement wherein the knife is heated, and the plastic tubular member is pulled against the sharp edge of the knife, the cut edges then continuing to move in contact with the heated surfaces of the knife member so that the cut edges of the plastic material are melted by the heated knife surfaces, and a bead is rolled at the edge to make a securely sealed edge.
While the prior art slit sealing apparatus has been used reasonably successfully for several years, as the extruders become larger, and the tube is formed faster, the temperature of the knife must be increased in temperature to attempt to form a secure seal and bead in the short length of time the plastic material is riding against the knife. Since polyethylene is basically flamable, it will be understood that an extremely high temperature will tend to burn the material and cause unsightly edges on the product. A lower temperature, with the short dwell times, simply provides for a poor seal which may break under normal use of the final product. One attempt at resolving this problem has been the use of heated air to preheat the plastic material in the area to be slit and sealed so that the subsequent slit sealer can seal more effectively. While such an arrangement may slightly enhance the sealing of the material, such an arrangement will still not assure a good seal at extremely high extruder speeds.
SUMMARY OF THE INVENTION
The present invention overcomes the above mentioned and other difficulties with the prior art slit sealing apparatus by providing fluid means for sealing a longitudinal path of the tubular member coming from the extruder, and heated knife means for severing the sealed path. More specifically, the present invention includes means for heating air or other appropriate fluid, distributor means for distributing the heated air over a portion of the path of travel of the plastic tube in conjunction with platen means for defining the sealed path. Adjacent to the sealing means and located along the sealed path, there is a knife for severing the sealed path, the knife being heated only sufficiently to prevent an accumulation of plastic residue thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention will become apparent from consideration of the following specification when taken in conjunction with the accompanying drawings in which:
FIG. 1 is a top plan view of a slit sealing apparatus made in accordance with the present invention;
FIG. 2 is an enlarged cross-sectional view taken substantially along the line 2--2 in FIG. 1; and,
FIG. 3 is a fragmentary view, partially in cross-section, showing the sealing means made in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to the drawings, and to that embodiment of the invention here chosen by way of illustration, FIG. 1 shows a large tube of material 10 as such material would come from an extruder. Those skilled in the art will realize that the film is extruded as a tube 10, and the tube is filled with air so that portions of the material do not touch other portions of material until the material has cooled sufficiently that no sticking will occur. The tube 10 is then carried to a pair of pinch rolls 11 which flatten the tube 10 into a web 12. This web 12 is fed under a roller 14 which holds the web against a roll 15 where the sealing device generally indicated at 16 seals a path 18, the path 18 comprising a strip along the web 12 wherein the two layers of the web 12 are sealed together. After the sealing apparatus 16 seals the strip, or path 18, a cutting means generally indicated at 19 severs the path 18 to yield two separate tubular members 20 and 21.
Those skilled in the art will realize that, when the members 20 and 21 are separated, some means must be utilized to maintain the severed edges apart until the edges are sufficiently cooled that there is no danger of rejoining. There is here shown a plurality of rollers as are conventional so that the two tubular members 20 and 21 are vertically separated after severing to maintain the desired separation. Also, a crowned roller may be used to effect the required separation.
It should further be understood that the embodiment of the invention here presented by way of illustration shows a single tubular member 10 and a single sealing means 16 and severing means 19 so that two smaller tubular members 20 and 21 are provided. A plurality of sealing means 16, and a plurality of severing means 19, can be easily distributed along the roll 15 and along the web 12 to provide three or more smaller tubular members such as the members 20 and 21. For a given size of tubular members 10, two or more of the sealing and severing means may be used to make smaller diameter tubular members; or, in the event larger tubular members 10 are provided, a plurality of the sealing and severing means may be required to produce the same final sizes of members such as the members 20 and 21.
Looking now at FIG. 2 of the drawings for a better understanding of the operation of the sealing and severing means of the present invention, it will be seen that the sealing means 16 includes an air inlet 22 which receives air or other gas under pressure, and directs the gas into the heating chamber 24. The air passes from the heating chamber 24 into the fluid distributer 25.
As was previously mentioned, the web 12 passes around the roller 14, and the roller 14 serves to hold the web 12 against a relatively long arc on the surface on the roll 15. Though considerable variation is possible as will be discussed in more detail hereinafter, the distributor 25 covers approximately a 120° arc, and the roller 14 must be placed sufficiently beyond that arc to hold the web 12 in position to be sealed by the fluid distributor 25. The web 12 then leaves the upper point of the roller 15 and extends generally horizontally for a short distance before engaging the cutting edge 26 of the severing means 19.
Returning now to the heating chamber 24, it will be understood that any form of heater to heat air will operate quite well in the present invention. Heaters with heat transfer fins may be used for more efficient heat transfer, and other conventional designs may be used. However, the heating chamber 24 is here shown as including two chambers 28 and 29, each of the chambers 28 and 29 including an electric heating element such as the elements indicated at 30 and 31. The air inlet 22 is shown at one end of the chamber 28, and a connecting passageway 32 is shown at the opposite end of the chamber 28. As a result, air will be received through the inlet 22 and be required to traverse the entire length of the chamber 28 where it is exposed to heat of the electric heater 30; then, the air can pass through the passageway 32 and into the chamber 29 where it must traverse the full length of the chamber 29 in contact with the heating element 31 in order to pass through the outlet 32.
It should be observed that the outlet 32 contains a constriction 34. It has been found that the constriction 34 improves the operation of the device by delaying the air passing from the air inlet 22, through the heater chambers 28 and 29 and into the air distributor 25. If the air is allowed to pass at its normal speed through the heater chambers, the air may not receive enough heat for best operation; however, with the constriction 34 to cause a back pressure, the air is delayed sufficiently that the air can be well heated before being admitted to the fluid distributor 25.
The hot air is admitted into the distributor 25 where the central opening 35 allows the heated air to be immediately distributed throughout the approximately 120° arc. Spaced along the inner wall 36, there is a plurality of apertures 38 through which the air will be directed against the film 12 as it traverses the roll 15.
At this point, it should be understood that the linear speed of the tubular member 10 will vary with different extruders. With any sealing operation, there must be some minimum dwell time. As the dwell time is decreased, the temperature must be increased in order to heat the material sufficiently to allow the desired sealing. In the arrangement shown in FIG. 2 of the drawings, it will be understood that, with a given size of roll 15, the length of the arc covered by the air distributor 25 will vary the dwell time. Of course, the roll 15 can be increased or decreased in size so long as the air distributor 25 can be sufficiently long to give the necessary dwell time.
Attention is now directed to the severing means 19 as shown in FIG. 2 of the drawings. It will here be seen that the severing means 19 includes the knife 39 having the cutting edge 26, the knife 39 being mounted in a block 40 which is heated by an appropriate electrical heating means the electrical line 41 being shown for connection to the heater. Since it is desirable to control the temperature of the block 40, hence the knife 39, the block 40 also includes a temperature sensing means having the lead 42 extending therefrom.
While it is possible to sever the path 18 with a cold but very sharp knife, it has been found that there tends to be an accumulation of plastic material on the sharp edge of the knife, and the use of heat has been found to dissipate this build-up and allow the knife to remain clean for considerable periods of operation. While circular cutters or other means may be used to prevent the build-up of material, the use of a heated knife is both simple and effective.
It has been found that the rapid flow of material across the cutting edge 26 removes a large amount of heat from the cutting edge, so the use of heaters only for the block 40 may not provide the needed quantity of heat in the cutting edge 26. Failure to maintain a high enough temperature in the cutting edge 26 will result in a build-up of material on the edge 26.
To assure that the cutting edge 26 remains hot enough to remain clean, it has been found desirable to pass an electric current through the blade itself. In the embodiment of the invention here illustrated, this is accomplished through the provision of a second block 40' having an electric cable 41' connected thereto. The block 40' is disposed below the web 12 for connection to the lower end of the knife 39. Thus, an electric current can be passed through the knife 39 to maintain the desired temperature.
If desired, of course, the knife 39 can be made in a U-shape so both ends are above the web 12 for easy connection; or, the lower end of the knife 39 may be a removable plug to allow the knife 39 to be removed from the web 12.
It is important to understand at this point that the severing means 19 does not in any way participate in the sealing of the edges of the layers of the material in the web 12. The sealing means 16 provides a complete seal between the layers of the material, and the severing means 19 simply severs the sealed path 18. The heating of the knife 39 is solely to keep the cutting edge 26 of the knife 39 free of build-up. Further, it is desirable to keep the knife 39 thin to prevent any sealing at the knife because there would be a bead rolled at the edge. Such a bead is unnecessary and undesirable.
It will be readily seen that sufficiently hot air blowing against a thermoplastic web will cause some sealing between the separate layers of the web. In a slit sealing arrangement such as that contemplated herein, it is highly desirable to have a discrete sealed area, or path, 18 rather than the somewhat random area that may be achieved by simply a blast of hot air. To achieve this discrete sealed area, it has been found that a platen in conjunction with the carefully controlled heated air will yield a well defined sealed area, or path, 18.
In FIG. 3 of the drawings, it will be seen that the roll 15 has a raised portion, or platen 44 thereon, somewhat as a plateau on the surface of the roll 15. It will be understood that the platen 44 extends completely, circumferentially around the roll 15, and the platen 44 is precisely aligned with the apertures 38 in the distributor 25. As is best shown in FIG. 3, the platen 44 holds the two layers 12a and 12b away from the roller 15 and towards the apertures 38. With this arrangement, as the heated air is expelled through the apertures 38, the air impinges directly on the web 12, and particularly on the portion of the web 12 that is supported by the platen 44. With such an arrangement, it has been found that there will be a sealed area having precise definition, and as wide as the platen 44.
While the platen 44 may be formed by numerous means, in one successful embodiment of the invention, it has been found that tape having an adhesive backing can be wrapped around the roll 15 to provide the platen 44. The particular tape used has been approximately 1/8 inch, or about 3 mm wide, and a very neat and well defined sealed area or path 18 has been achieved. It is also contemplated within the scope of the present invention to provide a platen 44 formed integrally with the roll 15. For example, the platen could be machined on the roll 15 when the roll itself is finished. Further, a plurality of platens could be spaced along the roll 15 to make one roll adaptable to a wide variety of slit-sealing operations.
From the foregoing, it will be realized that the height of the platen 44 is not truly critical. If the platen is too small, the sealing will be accomplished but the definition of the edges will not be good; if the platen is too large, the sealing will be accomplished but there will be some distortion of the film. It has been found for general purposes that a platen around 0.010 to 0.015 inch, or 0.2 to 0.5 mm, operates satisfactorily. The foregoing guidelines will allow those skilled in the art to select the particular height desired for any given operation.
FIG. 3 of the drawings also shows a portion of the web 12 after the sealed path 18 has been provided, the path 18 being shown as well defined by discrete sealed edges 46. The knife 39 must then be located between these sealed edges 46 to sever the path 18 generally centrally thereof. It will also be obvious to those skilled in the art that a wider pathway 18 may be provided if greater latitude in severing is required, or a narrower path 18 may be provided if the web can be controlled closely enough for the severing means to sever the middle of the path 18 and provide well sealed edges on both the members.
From the foregoing it should be understood that a tubular member 10 will be directed from a conventional extruder, and the tubular member 10 will be flattened into a web 12 by pinch rolls 11 or the like. The web 12 is then wrapped around a roll such as the roll 15, and heated air is distributed along an arc of the roll 15. The heated air should be heated to a temperature slightly above the melt point of the thermoplastic involved. Polyethylene melts at temperatures from about 185° to about 230° F., or 85° to 110° C., so the temperature of the air should be slightly above these temperatures. Of course the low density and high density polyethylenes vary in the amount of heat required, and precise temperatures must, in any case, be selected for the particular film involved. It is important to note, however, that a further increase in temperature of the air is not particularly effective, but the pressure of the air is important in obtaining a proper seal. In general, around 30 to 40 psig as measured at the entrance 22 to the heater 24 will be effective on polyethylene, and the pressure should be increased in the event a good seal is not obtained.
Once the sealed path 18 has been provided by the sealing means 16, the web 12 passes to the severing means 19. It will be understood that the severing means 19 should be as close as practicable to the sealing means 16 since the sealed path 18 will be easier to sever before the sealed path 18 cools completely. The web 12 is moved by means of the various rollers, and is held as taut as is reasonably possible for maximum control. The blade 39 will be reasonably thin, the object being simple to sever the web, and an extremely thick blade 39 will tend to roll a bead at the edge of the material. Thus, the sharp edge 26 of the knife 39 cuts the sealed path 18, and the heated blade keeps the cutting edge 26 clean and free of build-up. The temperature may be held by means of appropriate temperature control apparatus through the detecting means hereinabove discussed, or the current through the blade can be gradually increased until there is no accumulation of material.
It will therefore be seen that the present invention provides an extremely simple but highly effective method and apparatus for making a longitudinal seal on a multi-layer web, and severing the sealed area. The provision of an effective seal without a rolled bead is desirable both in that the seal is well made and secure, and the absence of a bead at the edge of the material allows the material to be placed into a roll and rolled neatly without the interference of the usual bead.
It will of course be understood by those skilled in the art that the particular embodiment of the invention here presented is by way of illustration only, and is meant to be in no way restrictive; therefore, numerous changes and modifications may be made, and the full use of equivalents resorted to, without departing from the spirit or scope of the invention as defined in the appended claims.
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A method for dividing an extruded tube into a plurality of smaller tubes is disclosed. The method includes the steps of flattening the tube into a web, sealing one or more longitudinal strips, or paths, along the web, and cutting generally the middle of the paths to separate the different smaller pieces. The apparatus includes a roll having a raised platen circumferentially thereof, and an air distributor to direct heated air against the web on the platen to effect a seal in the area of the platen. The web, with the sealed strips, is moved past a knife that severs the strip, and the knife is heated to prevent the accumulation of material thereon.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to storage racks, and more particularly pertains to a new and improved rack for holding stereo and television remote control devices.
2. Description of the Prior Art
The prior art is replete with various types of racks for holding virtually any conceivable item. Many of these racks are mounted on swivel bases, while also having variously positioned vertical and horizontal support shelves. A typical prior art rack is to be found in U.S. Pat. No. 3,433,364, which issued to T. Chen on Mar. 18, 1969. The rack disclosed in this patent is effectively a revolving foldable bookstand and includes a plurality of vertical supports for retaining books on a top planar surface of the rack. This rack is illustrative of a far greater number of patented racks, with the particular novelty of each of the racks residing in their support shelf positioning for holding particular unique items. More specifically, the Chen rack is specially designed to hold books, and would not be particularly useful for holding other types of items, although other items could be supported thereby.
Another innovative rack is disclosed in U.S. Pat. No. 3,889,817, which issued to J. Berkman on June, 1975. The rack disclosed in this patent includes a generally square-shaped supporting surface with four dividing walls radiating outwardly from the center. Slots are provided in the walls for receiving magnetic tape cartridges. As can be appreciated, this rack is essentially similar to the above-discussed rack; however, its most functional and efficient use is for the storage of magnetic tape cartridges. Other items stored on the rack would not fit properly thereon, and it is unlikely that such other uses of the rack would be anticipated by an owner.
As such, it can be appreciated that there are literally hundreds of designs for racks which initially appear substantially similar, while their functional utility is limited therebetween to certain shaped and sized items. More particularly, the storage of different items requires differently designed racks. Although numerous rack designs are currently commercially available, there are apparently no specially designed racks for holding stereo and television remote control devices and as such, it would appear that there exists a need for such a specially designed rack structure. In this respect, the present invention substantially fulfills this need.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of support racks now present in the prior art, the present invention provides an improved support rack construction wherein the same is particularly designed for the storage of stereo and television remote control devices. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved support rack which has all the advantages of the prior art support rack constructions and none of the disadvantages.
To attain this, the present invention comprises a substantially rectangularly shaped rack structure having a plurality of horizontally adjustable shelves The shelves are retained within slots formed within the box-like rack housing, with the shelves being slidably removable and repositionable to obtain the desired height adjustment. As such, the storage capacity between shelves can be varied to accommodate the various sized remote control devices now available for the control of stereo apparatuses and televisions.
Additionally, the rack structure may include either a fixed or swivel base, while a side positioned slot may be provided for holding a television guide or the like. If desired, a carrying handle can be attached to a topmost surface of the rack to facilitate a transporting thereof.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. Those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
It is therefore an object of the present invention to provide a new and improved support rack which has all the advantages of the prior art support racks and none of the disadvantages.
It is another object of the present invention to provide a new and improved support rack which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new and improved support rack which is of a durable and reliable construction.
An even further object of the present invention is to provide a new and improved support rack which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such support racks economically available to the buying public.
Still yet another object of the present invention is to provide a new and improved support rack which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
Still another object of the present invention is to provide a new and improved support rack which is particularly designed for the storage of stereo and television remote control devices.
Yet another object of the present invention is to provide a new and improved support rack which includes horizontally adjustable shelves.
Those together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a rear perspective view of a first embodiment of the remote control organizer rack comprising the present invention.
FIG. 2 is a front elevation view thereof.
FIG. 3 is a left side elevation view of the invention.
FIG. 4 is a right side elevation view of the present invention.
FIG. 5 is a top plan view of the present invention.
FIG. 6 is a bottom plan view of the invention.
FIG. 7 is a rear elevation view of the present invention.
FIG. 8 is a bottom perspective view of a modified embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to the drawings, and in particular to FIGS. 1-7 thereof, a new and improved support rack embodying the principles and concepts of the present invention and generally designated by reference numeral 10 will be described.
More specifically, it will be noted that the support rack 10 essentially comprises a rectangularly-shaped housing 12. In this respect, the housing 12 is formed of integral or separable planar surfaces which form a top surface 14, a bottom surface 16, left and right respective vertical sidewalls 18, 20, and a vertical rear wall 22. In the separable construction, the planar sections 14-22 may be attached together by any conventional means, such as through the use of glue, threaded fasteners, or the like, to thereby form the aforementioned housing 12.
Further illustrated in the drawings is a plurality of downwardly extending, surface contacting supports 24, which could be formed of a flexible rubber-like material to prevent abrasive damage to furniture and the like. The supports 24 can vary in number and can be constructed of any conceivable material which would perform the desired function, while the supports may be attached to the housing 12 by any conventional means as above-mentioned.
As best illustrated in FIGS. 1 and 2, a further upstanding planar support 26 may be attached to a bottommost portion of the sidewall 18. The planar section 26 may be integrally or otherwise attached to the wall 18 by a horizontal section 28, thereby to define a slot between the walls 18, 26. The slot formed by the walls 18, 26 is particularly well designed for receiving and supporting a television guide or some other similar publication.
As is also best illustrated in FIGS. 1 and 2, interior portions of the sidewalls 18, 20 are provided with parallelly-aligned inwardly extending slots 28 which are designed to slidingly receive and support a plurality of horizontally positioned shelves 30. The shelves 30 may be removed from the housing 12 when desired and may be repositioned therein in any pair of chosen slots 28, to thus vary the storage space between adjacent shelves. As such, storage space adjustability is provided to facilitate various sizes of remote control devices.
FIG. 8 of the drawings illustrates a modified embodiment of the invention wherein the surface supports 24 have been replaced with a single swivel base 32. The swivel base 32 is rotatable relative to the housing 12 and may be attached thereto by any conventional means. The swivel base 32 allows a rotation of the housing 12 to facilitate access to various remote control devices contained therein.
With respect to the manner of usage and operation of the present invention 10, such usage and operation should be apparent from the above description. Accordingly, no further discussion relative thereto will be provided.
With respect to the above description then, it is to realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A rack is specially designed for holding stereo and television remote control devices. The rack includes horizontally adjustable shelves and may further include either a fixed or swivel base. The rack also includes a special holder for a television guide book or the like.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2010-0103805 filed Oct. 25, 2010, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] (a) Technical Field
[0003] The present invention relates to a heating device for an end plate of a fuel cell stack. More particularly, it relates to a heating device for an end plate of a fuel cell stack, which can prevent a decrease in temperature of unit cells around the ends of the fuel cell stack by providing a structure for circulating high temperature coolant discharged from the fuel cell stack in the end plate. A non-uniform temperature distribution in the fuel cell stack can thereby be prevented.
[0004] (b) Background Art
[0005] First, the configuration of a fuel cell stack (hereinafter referred to also as stack) will be briefly described with reference to FIGS. 6 and 8 below.
[0006] A membrane-electrode assembly (MEA) is positioned in the center of each unit cell of the fuel cell stack, and the MEA comprises a solid polymer electrolyte membrane 10 , through which hydrogen ions (protons) are transported, and an electrode/catalyst layer such as a cathode (“air electrode”) 12 and an anode (“fuel electrode) 14 , in which an electrochemical reaction between hydrogen and oxygen takes place, disposed on both sides of the polymer electrolyte membrane 10 .
[0007] Moreover, a gas diffusion layer (GDL) 16 and a gasket 18 are sequentially stacked on both sides of the MEA, where the cathode 12 and the anode 14 are located. A separator 20 including flow fields, through which reactant gases (such as hydrogen as a fuel and oxygen or air as an oxidant) are supplied and coolant passes, is located on the outsides of each GDL 16 .
[0008] After several hundreds of unit cells are stacked, an end plate 30 for supporting and fixing the unit cells is connected to each end of the fuel cell stack.
[0009] Further, a current collector 32 for collecting electricity generated in the stack and supplying the electricity to the outside is mounted on the inside of each end plate 30 .
[0010] An oxidation reaction of hydrogen occurs at the anode 14 of the stack to produce hydrogen ions (protons, H + ) and electrons (e − ) by a catalyst disposed in the electrode/catalyst layer. The hydrogen ions and electrons are transmitted to the cathode 12 through the electrolyte membrane 10 and the separator 20 . At the cathode 12 , water is produced by the electrochemical reaction between the hydrogen ions and electrons transmitted from the anode 14 and the oxygen-containing air. Electrical energy generated by the flow of electrons is supplied to a load that uses the electrical energy through the current collector 32 of the end plate 30 .
[0011] Hydrogen inlet and outlet manifolds, air inlet and outlet manifolds, and coolant inlet and outlet manifolds are further formed adjacent to each other on the separators 20 as well as the end plates 30 .
[0012] The flow of coolant for cooling the unit cells of the stack is as follows. As shown in FIG. 6 , the coolant supplied through a coolant inlet manifold 34 cools the unit cells of the stack and is then discharged through a coolant outlet manifold 36 .
[0013] However, when measuring the temperature of the coolant in the coolant outlet manifold 36 , it can be seen from the graph of FIG. 7 , which displays the temperature for the various cells in the stack, that the temperature of the coolant at the upstream is high and gradually decreases at the downstream. In other words, the temperature of the coolant increases as it cools the unit cells of the stack, and then gradually decreases as the coolant flows toward the outlet of the end plate through the coolant outlet manifold.
[0014] If the temperature of the coolant decreases as the coolant flows toward the outlet of the end plate through the coolant outlet manifold, the temperature of unit cells adjacent to the end plate also decreases, and thus a non-uniform temperature distribution occurs in the entire unit cells.
[0015] A typical polymer electrolyte membrane fuel cell generally exhibits excellent performance in a temperature range from room temperature to 80° C. However, if the non-uniform temperature distribution occurs in the entire unit cells as the temperature of several unit cells is lowered, the performance is reduced by a reduction in reaction activity and a reduction in ion conductivity of the electrolyte membrane.
[0016] In particular, if the temperature of the stack mounted in a vehicle is lowered below the freezing point (e.g. if the outside temperature is below zero such as in winter conditions), the activity of the electrodes including the cathode and the anode in the stack is reduced. Moreover, the water carrying hydrogen ions in the electrolyte membrane freezes in the stack, which reduces the ion conductivity of the electrolyte membrane, thereby deteriorating the performance of the stack.
[0017] Further, if the temperature of the stack is low while humidified gas is supplied to the stack, a flooding problem occurs due to condensation of water. This has a critical effect on the performance and durability of the stack. Therefore, in order to operate the fuel cell stack at an appropriate temperature, it is very important to uniformly maintain the temperature distribution of the fuel cell stack, in which several hundreds of unit cells are stacked together, in a predetermined range.
[0018] Taking these factors into account, many methods have been devices in an attempt to prevent a decrease in temperature of unit cells adjacent to the end plate. For example, methods have been proposed wherein a device is inserted for thermally insulating or heating the area between the end plate and the stacked cells.
[0019] For example, U.S. Pat. No. 6,824,901 describes a method of inserting a thick insulator between an end plate and a separator to thermally insulate the region where the reaction occurs, or disposing a plane heater between the end plate and the separator to maintain the temperature of the entire fuel cell stack at a predetermined level during cold start-up.
[0020] Korean Patent No. 10-2006-0077284 describes a fuel cell stack, in which different types of current collectors having different coefficients of thermal expansion are provided to generate heat, thereby thermally insulating unit cells around the end plate.
[0021] Korean Patent No. 10-2006-0074397 describes a stack fixture structure for cold start-up of a fuel cell vehicle, in which a cover for covering the outside of an end plate is attached to a fuel cell stack to form an air layer for thermal insulation.
[0022] However, in the case where the entire end plate is thermally insulated, the thickness of the insulator for the thermal insulation should be increased, which increases the thickness of the entire fuel cell stack. In the case where the cover is attached to the outside of the end plate, it is impossible to prevent the heat generated in the electrodes from being transferred to the end plate. Moreover, in the case where the heater is disposed between the end plate and the separator, it is necessary to supply an external power source for the operation of the heater, and thus a system for controlling the heater and power supply is complicated.
[0023] Accordingly, there remains a need in the art for an apparatus and method for maintaining a uniform temperature distribution in a fuel cell stack.
[0024] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
SUMMARY OF THE DISCLOSURE
[0025] The present invention provides a heating device for an end plate of a fuel cell stack. The heating device can uniformly maintain the temperature distribution of unit cells constituting the fuel cell stack in a predetermined range in such a manner that high temperature coolant flowing from the upstream of a coolant outlet manifold to the downstream is allowed to circulate through the inside of the end plate and to be discharged to the outside. As such, the thermal energy of the coolant is supplied to the end plate and, at the same time, is transferred to unit cells adjacent to the end plate.
[0026] In one aspect, the present invention provides a heating device for an end plate of a fuel cell stack, the device comprising a coolant circulator provided within the end plate such that all or part of the high temperature coolant flowing through a coolant outlet manifold flows through the coolant circulator. As such, the thermal energy of the coolant is transferred to the end plate and unit cells adjacent to the end plate.
[0027] In a preferred embodiment, the coolant circulator comprises: a single coolant inlet and a single coolant outlet formed on one end of the end plate and being in contact with the coolant outlet manifold, wherein the single coolant outlet can be provided in front of the fuel cell stack and the single coolant inlet can be provided in the rear of the single coolant outlet; and a single coolant flow field connected between the single coolant inlet and the single coolant outlet and formed inside the end plate through which the coolant is circulated.
[0028] In another preferred embodiment, the single coolant flow field comprises: a single upstream channel extending from the single coolant inlet to the inside of the other end of the end plate, which is in contact with a coolant inlet manifold, through one side of the end plate; and a single downstream channel extending from the other end of the end plate to the single coolant outlet through the other side of the end plate.
[0029] In still another preferred embodiment, the coolant circulator comprises: multiple coolant inlets and multiple coolant outlets formed on one end of the end plate being in contact with the coolant outlet manifold, the multiple coolant inlets or multiple coolant outlets being provided in front of the fuel cell stack; and multiple coolant flow fields connected between the multiple coolant inlets and the multiple coolant outlets and formed inside the end plate through which the coolant is circulated.
[0030] In yet another preferred embodiment, the multiple coolant flow fields comprise: multiple upstream channels extending from the multiple coolant inlets to the inside of the other end of the end plate, which is in contact with a coolant inlet manifold, through one side of the end plate, the multiple upstream channels forming several separate spaces in the end plate in the left and right direction; and multiple downstream channels extending from the other end of the end plate to the multiple coolant outlets through the other side of the end plate, the multiple downstream channels forming several separate spaces in the end plate in the left and right direction.
[0031] In still yet another preferred embodiment, each of the multiple coolant inlets is integrally formed with a vane for guiding the flow of the coolant.
[0032] In a further preferred embodiment, the height of the vanes formed on the multiple coolant inlets increases as it goes from the upstream of the coolant outlet manifold to the downstream.
[0033] In another further preferred embodiment, the multiple upstream channels of the multiple coolant flow fields are provided in parallel to each other on one side of left and right sides, and the multiple downstream channels are provided in parallel to each other on the other side of the left and right sides.
[0034] In still another further preferred embodiment, each of the multiple upstream channels of the multiple coolant flow fields and each of multiple downstream channels of the multiple coolant flow fields are formed alternately on the left and right sides.
[0035] Other aspects and preferred embodiments of the invention are discussed infra.
[0036] It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles.
[0037] The above and other features of the invention are discussed infra.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The above and other features of the present invention will now be described in detail with reference to certain exemplary embodiments thereof illustrated the accompanying drawings which are given hereinbelow by way of illustration only, and thus are not limitative of the present invention, and wherein:
[0039] FIG. 1 is a cross-sectional view showing a heating device for an end plate of a fuel cell stack in accordance with a first embodiment of the present invention.
[0040] FIG. 2 is a cross-sectional view showing a heating device for an end plate of a fuel cell stack in accordance with a second embodiment of the present invention.
[0041] FIG. 3 is a cross-sectional view showing a heating device for an end plate of a fuel cell stack in accordance with a third embodiment of the present invention.
[0042] FIG. 4 is a cross-sectional view showing a heating device for an end plate of a fuel cell stack in accordance with a fourth embodiment of the present invention.
[0043] FIG. 5 is a cross-sectional view showing a heating device for an end plate of a fuel cell stack in accordance with a fifth embodiment of the present invention.
[0044] FIG. 6 is a cross-sectional view showing the flow of coolant of a fuel cell stack.
[0045] FIG. 7 is a graph showing a change in temperature of coolant flowing through a coolant outlet manifold of a fuel cell stack.
[0046] FIG. 8 is a schematic diagram showing the configuration of a typical fuel cell stack.
[0047] Reference numerals set forth in the Drawings includes reference to the following elements as further discussed below:
[0000]
10: electrolyte membrane
12: cathode
14: anode
16: gas diffusion layer
18: gasket
20: separator
30: end plate
32: current collector
34: coolant inlet manifold
36: coolant outlet manifold
40: coolant circulator
41: single coolant inlet
42: single coolant outlet
43: single coolant flow field
44: single upstream channel
45: single downstream channel
50: coolant circulator
51: multiple coolant inlet
52: multiple coolant outlet
53: multiple coolant flow field
54: multiple upstream channel
55: multiple downstream channel
56: vane
[0048] It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.
[0049] In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.
DETAILED DESCRIPTION
[0050] Hereinafter reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. While the invention will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention to those exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
[0051] As mentioned above, when the temperature of coolant after cooling a fuel cell stack decreases as the coolant flows toward an outlet of an end plate through a coolant outlet manifold, the temperature of unit cells adjacent to the end plate also decreases. As a result, a non-uniform temperature distribution occurs in the entire unit cells.
[0052] The present invention provides a method and apparatus for maintaining the temperature distribution of unit cells constituting a fuel cell stack in a predetermined range. In particular, according to the present invention, the thermal energy of high temperature coolant discharged after cooling the unit cells of the stack is transferred to an end plate and unit cells adjacent to the end plate, to thereby reduce and even prevent a temperature decrease of the unit cells adjacent to the end plate at the end of the fuel cell stack during operation.
[0053] For example, as shown in the figures, a separate coolant circulator 40 is provided inside the end plate 30 such that all or part of the high temperature coolant that cools the unit cells of the stack and flows through a coolant outlet manifold 36 is introduced into the coolant circulator 40 .
[0054] Therefore, the thermal energy of the coolant flowing through the coolant circulator 40 is easily transferred to the end plate 30 and the unit cells adjacent to the end plate 30 , and a decrease in temperature of the unit cells adjacent to the end plate 30 at the end of the fuel cell stack can be reduced and even prevented.
[0055] Next, the configuration and operation of a coolant circulator in accordance with a first embodiment of the present invention will be described with reference to FIG. 1 .
[0056] In the coolant circulator 40 shown in FIG. 1 , a single coolant inlet 41 and a single coolant outlet 42 are formed on one end (“bottom” end, as shown in the figures) of the end plate 30 and are disposed so as to be in contact with the coolant outlet manifold 36 . In particular, the single coolant outlet 42 can be provided in front of the stack (i.e., at the final discharge port of the coolant), while the single coolant inlet 41 can be provided in the rear of the single coolant outlet 42 , as shown.
[0057] As further shown, a single coolant flow field 43 connected between the single coolant inlet 41 and the single coolant outlet 42 is provided inside the end plate 30 .
[0058] In particular, the single coolant flow field 43 can comprise a single upstream channel 44 and a single downstream channel 45 . As shown, for example, the single upstream channel 44 can extend from the single coolant inlet 41 to the inside of the other end (“top” end as shown in the figures) of the end plate 30 , which is in contact with a coolant inlet manifold 34 , through one side of the end plate 30 . The single downstream channel 45 can then extend from the other end (“top” end) of the end plate 30 to the single coolant outlet 42 through the other side of the end plate 30 .
[0059] Therefore, the low temperature coolant supplied through the coolant inlet manifold 34 cools the unit cells of the stack to absorb heat, and then flows through the coolant outlet manifold 36 .
[0060] Subsequently, all or part of the high temperature coolant flowing from the upstream of the coolant outlet manifold 36 to the downstream is supplied to the single coolant flow field 43 through the single coolant inlet 41 .
[0061] The coolant supplied through the single coolant inlet 41 then flows along the single upstream channel 44 and through the one side of the end plate 30 , and then flows along the single downstream channel 45 to the single coolant outlet 42 through the other side of the end plate 30 .
[0062] Here, the thermal energy from the high temperature coolant flowing through the single upstream channel 44 and the single downstream channel 45 is transferred to the end plate 30 and the unit cells adjacent to the end plate 30 to maintain the temperature of the unit cells adjacent to the end plate 30 . As a result, it is possible to reduce and even to prevent the decrease in temperature of the unit cells, and thus it is possible to uniformly maintain the temperature distribution of the unit cells constituting the stack within a predetermined range.
[0063] Next, the configuration and operation of a coolant circulator in accordance with a second embodiment of the present invention will be described with reference to FIG. 2 .
[0064] In the coolant circulator 50 as shown in FIG. 2 , multiple coolant inlets 51 and multiple coolant outlets 52 are formed on one end (“bottom” end) of an end plate 30 being in contact with a coolant outlet manifold 36 . For example, two coolant outlets 52 can be provided in parallel to each other in front of the stack (i.e., at the final discharge port of the coolant) and two coolant inlets 51 can be provided in parallel to each other in the rear of the multiple coolant outlets 52 . Of course, the coolant inlets and outlets 51 , 52 are not limited to only two, and any multiple number of coolant inlets and outlets 51 , 52 can be provided.
[0065] As further shown, multiple coolant flow fields 53 can be disposed within the end plate 30 between the multiple coolant inlets 51 and the multiple coolant outlets 52 .
[0066] In particular, the multiple coolant flow fields 53 can comprise multiple upstream channels 54 extending from the multiple coolant inlets 51 to the inside of the other end (“top” end) of the end plate 30 , which is in contact with a coolant inlet manifold 34 , through one side of the end plate 30 , and multiple downstream channels 55 extending from the other end (“top” end) of the end plate 30 to the multiple coolant outlets 52 through the other side of the end plate 30 .
[0067] For example, the multiple upstream channels 54 can form several separate spaces in the end plate 30 in the left and right direction, and the multiple downstream channels 55 can also form several separate spaces in the end plate 30 in the left and right direction. In a preferred embodiment, the multiple upstream channels 54 of the multiple coolant flow fields 53 are disposed parallel to each other on the right side of the multiple downstream channels 55 , and the multiple downstream channels 55 of the multiple coolant flow fields 53 are disposed parallel to each other on the left side of the multiple upstream channels 54 . Of course, the invention is not limited to this specific arrangement and, for example, the multiple upstream channels 54 and the multiple downstream channels 55 of the multiple coolant flow fields 53 may be formed in one space, respectively, on the left and right sides.
[0068] As shown in connection with FIG. 2 , a vane 56 can be further provided for guiding the flow of the coolant. For example, the vane 56 can be integrally formed one or more of the multiple coolant inlets 51 . In accordance with a preferred embodiment, for example, as shown in FIG. 2 , the height of the vanes 56 formed on the multiple coolant inlets 51 increases from the upstream of the coolant outlet manifold 36 to the downstream.
[0069] For example, based on the flow direction of the coolant, a vane 56 having a smaller height can be mounted on the coolant inlet 51 at the upstream of the coolant outlet manifold 36 , while a vane 56 having a greater height can be mounted on the coolant inlet 51 at the downstream of the coolant outlet manifold 36 . As such, the flow of the coolant can be easily guided toward the multiple coolant flow fields 53 .
[0070] Therefore, the low temperature coolant supplied through the coolant inlet manifold 34 cools the unit cells of the stack to absorb heat, and then flows through the coolant outlet manifold 36 .
[0071] Subsequently, all or part of the high temperature coolant flowing from the upstream of the coolant outlet manifold 36 to the downstream is supplied to the multiple coolant flow fields 53 through the multiple coolant inlets 51 , preferably with the guidance of the vanes 56 .
[0072] For example, the coolant supplied through the multiple coolant inlets 51 flows along the multiple upstream channels 54 extending to the inside of the other end (“top” end) of the end plate 30 , which is in contact with the coolant inlet manifold 34 , through the one side of the end plate 30 , and then flows along the multiple downstream channels 55 extending from the other end (“top” end) of the end plate 30 to the multiple coolant outlets 52 through the other side of the end plate 30 .
[0073] Therefore, the thermal energy from the high temperature coolant flowing through the multiple upstream channels 54 and the multiple downstream channels 55 is transferred to the end plate 30 and the unit cells adjacent to the end plate 30 to maintain the temperature of the unit cells adjacent to the end plate 30 . As a result, it is possible to reduce and even to prevent the decrease in temperature of the unit cells, and thus to uniformly maintain the temperature distribution of the entire unit cells constituting the stack within a predetermined range.
[0074] Next, the configuration and operation of a coolant circulator in accordance with a third embodiment of the present invention will be described with reference to FIG. 3 .
[0075] In the coolant circulator shown in FIG. 3 , multiple coolant inlets 51 and multiple coolant outlets 52 are formed on one end (“bottom” end) of an end plate 30 being in contact with a coolant outlet manifold 36 . For example, two multiple coolant inlets 51 can be provided, preferably parallel to each other, in front of the stack (i.e., at the final discharge port of the coolant). Two multiple coolant outlets 52 can further be provided, preferably parallel to each other, in the rear of the multiple coolant inlets 51 . As noted in connection with FIG. 2 , any multiple number of coolant inlets and outlets 51 , 52 other than two can also be provided.
[0076] In the third embodiment, the positions of the multiple coolant inlets 51 and the multiple coolant outlets 52 are opposite to those in the second embodiment. Therefore, the positions of corresponding structures, particularly the multiple upstream channels 54 and multiple downstream channels 55 of multiple coolant flow fields 53 , are also opposite to those in the second embodiment.
[0077] Therefore, when the coolant is discharged through the multiple downstream channels 55 and the multiple coolant outlets 52 , the coolant may be reintroduced into the multiple downstream channels 55 in the second embodiment. However, in the third embodiment, the multiple downstream channels 55 and the multiple coolant outlets 52 are located on the downstream side compared to the multiple upstream channels 54 and the multiple coolant inlets 51 , and thus it is possible to prevent the coolant from flowing in reverse toward the multiple downstream channels 55 .
[0078] Likewise, in the third embodiment, the thermal energy from the high temperature coolant flowing through the multiple upstream channels 54 and the multiple downstream channels 55 is transferred to the end plate 30 and the unit cells adjacent to the end plate 30 , to thereby maintain the temperature of the unit cells adjacent to the end plate 30 . As a result, it is possible to reduce and to even prevent the decrease in temperature of the unit cells, and thus it is possible to uniformly maintain the temperature distribution of the entire unit cells constituting the stack within a predetermined range.
[0079] Next, the configuration and operation of coolant circulators in accordance with fourth and fifth embodiments of the present invention will be described with reference to FIGS. 4 and 5 .
[0080] In the coolant circulator in accordance with the fourth embodiment of the present invention ( FIG. 4 ), multiple coolant inlets 51 and multiple coolant outlets 52 are formed on one end (“bottom” end) of an end plate 30 being in contact with a coolant outlet manifold 36 . For example, a plurality of multiple coolant inlets 51 are provided, preferably parallel to each other, on one side of left and right sides (e.g. on the right side as shown in FIG. 4 ), and a plurality of multiple coolant outlets 52 are provided, preferably parallel to each other, on the other side of the left and right sides (e.g. on the left side as shown in FIG. 4 ).
[0081] According to some embodiments, one or more vanes 56 , preferably having an increasing height from the upstream to the downstream, are mounted on one or more of the multiple coolant inlets 51 .
[0082] Further, a plurality of multiple upstream channels 54 of multiple coolant flow fields 53 , formed inside the end plate 30 , are provided, preferably parallel to each other, on one side of left and right sides (e.g. on the right side as shown in FIG. 4 ), and a plurality of multiple downstream channels 55 are provided, preferably parallel to each other, on the other side of the left and right sides (e.g. on the left side as shown in FIG. 4 ). Thus, the multiple upstream channels 54 extend from the multiple coolant inlets 51 , and the multiple downstream channels 55 meet the multiple coolant outlets 52 .
[0083] In the coolant circulator in accordance with the fifth embodiment of the present invention ( FIG. 5 ), multiple coolant inlets 51 and multiple coolant outlets 52 are formed on one end (“bottom” end) of an end plate 30 being in contact with a coolant outlet manifold 36 . In particular, a plurality of multiple coolant inlets 51 and a plurality of multiple coolant outlets 52 are provided, preferably parallel to each other, and each of the multiple coolant inlets 51 and each of the multiple coolant outlets 52 are formed in an alternating arrangement, as shown.
[0084] Moreover, within the end plate a plurality of multiple upstream channels 54 and a plurality of multiple downstream channels 55 of multiple coolant flow fields 53 are provided, preferably parallel to each other, with each of the multiple upstream channels 54 and each of the multiple downstream channels 55 being provided in an alternating arrangement, as shown. The multiple upstream channels 54 extend from the multiple coolant inlets 51 , and the multiple downstream channels 55 meet the multiple coolant outlets 52 , respectively.
[0085] Therefore, the low temperature coolant supplied through the coolant inlet manifold 34 cools the unit cells of the stack to absorb heat and then flows through the coolant outlet manifold 36 .
[0086] Subsequently, all or part of the high temperature coolant flowing from the upstream of the coolant outlet manifold 36 to the downstream is supplied to the multiple coolant flow fields 53 through the multiple coolant inlets 51 , preferably with the guidance of the vanes 56 .
[0087] In particular, the coolant supplied through the multiple coolant inlets 51 flows along the multiple upstream channels 54 extending to the inside of the other end (“top” end) of the end plate 30 , which is in contact with the coolant inlet manifold 34 , through one side of the end plate 30 , and then flows along the multiple downstream channels 55 extending from the other end (“top” end) of the end plate 30 to the multiple coolant outlets 52 through the other side of the end plate 30 .
[0088] When the coolant is discharged through the coolant outlet manifold 36 , high inertia energy can be applied to the coolant by the guide vanes 56 , and thus the coolant is easily introduced into the multiple coolant inlets 51 , passes through the multiple upstream channels 54 , and flows through the multiple downstream channels 55 , whose pressure is relatively low, to the multiple coolant outlets 52 .
[0089] Likewise, the thermal energy from the high temperature coolant flowing through the multiple upstream channels 54 and the multiple downstream channels 55 is transferred to the end plate 30 and the unit cells adjacent to the end plate 30 , to thereby maintain the temperature of the unit cells adjacent to the end plate 30 . As a result, it is possible to reduce ad even to prevent the decrease in temperature of the unit cells, and thus it is possible to uniformly maintain the temperature distribution of the entire unit cells constituting the stack in a predetermined range.
[0090] As described above, the present invention provides the following effects.
[0091] According to the present invention, the coolant circulation flow field is provided in the end plate such that all or part of the high temperature coolant that cools the stack and is discharged from the upstream side of the coolant outlet manifold to the downstream side passes through the coolant circulation flow field, to transfer the thermal energy of the coolant to the end plate and the unit cells adjacent to the end plate. As such, the temperature distribution of the unit cells constituting the stack can be maintained within a predetermined range.
[0092] In particular, the thermal energy from the high temperature coolant flowing through the coolant circulation flow field in the end plate is transferred to the end plate and the unit cells adjacent to the end plate, to thereby reduce and even prevent the decrease in temperature of the unit cells. It is thus possible to uniformly maintain the temperature distribution of the entire unit cells constituting the stack within a predetermined range, thereby reducing and even preventing deterioration of performance of the stack.
[0093] The invention has been described in detail with reference to preferred embodiments thereof. However, it will be appreciated by those skilled in the art that changes may 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 and their equivalents.
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The present invention provides a heating device for an end plate of a fuel cell stack, which can prevent a decrease in temperature of unit cells around the ends of the fuel cell stack by providing a structure for circulating high temperature coolant discharged from the fuel cell stack in the end plate. Non-uniform temperature distribution in the fuel cell stack can thereby be prevented. In particular, a heating device for an end plate of a fuel cell stack is provided wherein high temperature coolant flowing from the upstream of a coolant outlet manifold to the downstream is allowed to circulate through the inside of the end plate and to be discharged to the outside such that the thermal energy of the coolant is supplied to the end plate and, at the same time, transferred to unit cells adjacent to the end plate.
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