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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/239,650 filed Oct. 12, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to latching devices, and more particularly to a side panel slam-to-close latching system for latching hinged doors or panels and the like to a corresponding frame for various uses, such as in vehicles.
[0004] 2. Brief Description of the Prior Art
[0005] Door-mounted “slam” latches employ a camming surface on the end of a sliding-bolt element that cooperates with a striker on the door frame to cause a bolt action to secure the door when it is closed against the frame. Such latches are activated to secure the door when the door is merely pushed shut or slammed. However, to open the door, operation of the latch mechanism is required to release the latch. In some slam latches, as the door is being closed, the bolt is urged against a spring force by the action of a camming surface cooperating with the striker to slide into the latch housing. Once the camming surface has passed the door frame inner surface, the spring force then urges the bolt element to engage behind the door frame, or to engage a keeper mounted on the door frame. In order to open the door, the bolt is manually operated, usually through a grip, to withdraw the bolt from engagement with the keeper.
[0006] Examples of prior art slam latches are disclosed in U.S. Pat. Nos. 3,841,674, 3,850,464, 5,482,333 and 5,628,634.
[0007] The spring force for such latches can be provided through separate spring elements, such as a torsion bar spring (FIGS. 8 - 9 , U.S. Pat. No. 3,841,674), a torsion coil spring (FIGS. 11 - 13 , U.S. Pat. No. 3,841,674), or a compression coil spring (FIG. 13, U.S. Pat. No. 3,841,674). Alternatively, the spring element can be integrally molded with a latch body made from an appropriate plastic or polymeric material (FIGS. 1 - 7 , U.S. Pat. No. 3,841,674; U.S. Pat. No. 5,842,333; FIG. 6A- 6 E, U.S. Pat. No. 5,628,534).
[0008] Slam latches with integrally molded spring elements have a number of advantages over slam latches that use separate metal springs. First, slam latches with integrally molded spring elements tend to be less expensive because fewer parts are required to be made and assembled for each latch. Further, during manufacture metal springs may become embrittled and thus subject to breakage.
[0009] On the other hand, prior art latches with integrally molded spring elements may not have the same life expectancy as those that use separate metal springs. Elements formed from polymeric materials that are subjected to cyclic stresses, such as integrally molded spring elements in slam latches, sometimes fail at stress levels far below their yield stress, due to fatigue failure.
[0010] Prior slam latches have employed generally planar integrally molded spring elements. Examples include those shown in FIGS. 1 - 7 of U.S. Pat. No. 3,850,464, and FIGS. 6 B- 6 E of U.S. Pat. No. 5,628,534. A variation is disclosed in U.S. Pat. No. 5,482,333, in which the spring member 5 includes two pairs of integrally hinged generally planar elements, molded from a suitable resin, such as polypropylene, in a relaxed configuration. In each of these designs, when the latch is operated stresses are generated primarily proximate the portion of the latch where the spring extends from the latch body.
[0011] There is a need for a simple, inexpensive slam latch having an integrally molded spring element that resists cyclic stresses and fatigue failure, and which can be easily and inexpensively manufactured with minimal parts, and which is user friendly.
SUMMARY OF THE INVENTION
[0012] The present invention provides a latch of the slam type for installation in an opening in a door or panel for releasably retaining the panel relative to a frame. The latch is particularly useful for securing carpeted panels, such as are found in automotive interiors.
[0013] The latch is adapted for installation in a generally rectangular opening or aperture formed in the panel near the edge of the door panel.
[0014] The latch includes a generally flat, rectangular upper plate, which is positioned above the door panel when the latch is mounted in the opening. In a presently preferred embodiment, the plate extends beyond the edge of the door panel and over the top of the frame, thereby serving to prevent inward movement of the door panel beneath the frame.
[0015] The latch also includes a generally box-like latch housing that extends and is molded directly under the plate and through the opening in the door panel when the latch is mounted in the door panel. The latch housing forms a central well, and the well extends through a generally rectangular central opening that is formed in the plate. The central well is divided into a pawl recess and an actuation recess, whereby a housing wall separates the pawl recess from the actuation recess.
[0016] The latch is a two-piece assembly comprising a pawl and a housing. The pawl is assembled within the housing, and snaps together. The pawl includes a living spring portion, which flexibly moves the locking portion of the pawl into and out of locking position under the frame.
[0017] The latch is operated in the following manner: the operator squeezes the pawl against the housing wall, using two fingers, one against the pawl and the other against the backside of the housing wall. As a result of the squeezing action, the pawl living spring flexes and the pawl moves away from the frame. When the pawl exits the frame completely the latch is unlocked and the operator can pull the latch and the panel will open. The pawl provides for a slam action by the use of a ramp shape, which interacts with the frame, which forces the pawl away from the frame and forces the pawl living spring to flex. After the latch has cleared the frame the pawl living spring relaxes and the pawl engages the frame, completing the latching process.
[0018] The latch is installed into the door panel by snapping. The lower part of the housing is placed into a hole provided for this purpose, while leaving the upper part of the housing (a flange or upper lip) above the surface of the panel.
[0019] It is an object of the present invention to provide a latch, which is useful for securing a door panel such as a door panel in a vehicle.
[0020] It is another object of the present invention to provide a latch, which includes a living spring member, which allows for the latch o return to its original position once it is released.
[0021] Still another object of the present invention is to provide a latch, which is easily mounted in the door or panel frame and can easily accommodate the door or panel.
[0022] Another object of the present invention is to provide a latch, which is designed relatively simply and inexpensive, yet can perform its function properly.
[0023] Yet another object of the present invention is to provide a latch, which comprises a minimum number of parts.
[0024] It is still another object of the present invention to provide a latch, which comprises two separate pieces, which snap-fit together for assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 is a perspective view of the side panel latch shown in the neutral position according to the present invention.
[0026] [0026]FIG. 2 is a top view of the side panel latch of FIG. 1 shown in the neutral position.
[0027] [0027]FIG. 3 is a bottom view of the side panel latch of FIG. 1 shown in the neutral position.
[0028] [0028]FIG. 4 is a perspective view of the side panel latch shown in the actuated position according to the present invention.
[0029] [0029]FIG. 5 is a top view of the side panel latch of FIG. 4 shown in the actuated position.
[0030] [0030]FIG. 6 is a bottom view of the side panel latch of FIG. 4 shown in the actuated position.
[0031] [0031]FIG. 7 is a perspective view of the pawl according to the present invention.
[0032] [0032]FIG. 8 is a top view of the pawl of FIG. 7.
[0033] [0033]FIG. 9 is a bottom view of the pawl of FIG. 7.
[0034] [0034]FIG. 10 is a perspective view of the housing according to the present invention.
[0035] [0035]FIG. 11 is a top view of the housing of FIG. 10.
[0036] [0036]FIG. 12 is a bottom view of the housing of FIG. 10.
[0037] [0037]FIG. 13 is a top view of the side panel latch installed in an assembly shown in the neutral position with the door or panel portion closed according to the present invention.
[0038] [0038]FIG. 14 is a bottom view of the side panel latch of FIG. 13 installed in an assembly shown in the neutral position.
[0039] [0039]FIG. 15 is a cross-sectional side elevation view of the side panel latch of FIG. 13 installed in an assembly shown in the neutral position.
[0040] [0040]FIG. 16 is a magnified view of the cross-sectional side elevation view of the side panel latch of FIG. 15 installed in an assembly shown in the neutral position.
[0041] [0041]FIG. 17 is an alternate cross-sectional perspective view of the side panel latch of FIG. 13 installed in an assembly shown in the neutral position.
[0042] [0042]FIG. 18 is a cross-sectional side elevation view of the side panel latch installed in an assembly shown in the actuated position.
[0043] [0043]FIG. 19 is a magnified view of the cross-sectional side elevation view of the side panel latch of FIG. 18 installed in an assembly shown in the actuated position.
[0044] [0044]FIG. 20 is a cross-sectional perspective view of the side panel latch installed in an assembly shown in the actuated position with the door or panel portion open.
[0045] [0045]FIG. 21 is an isolated cross-sectional perspective view of the side panel latch installed in an assembly shown in the actuated position.
[0046] [0046]FIG. 22 is a cross-sectional side elevation view of the side panel latch of FIG. 20 installed in an assembly shown in the actuated position with the door or panel portion open.
[0047] [0047]FIG. 23 is a magnified cross-sectional side elevation view of the side panel latch of FIG. 22 installed in an assembly shown in the actuated position with the door or panel portion open.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] Referring now to the drawings in detail, wherein like reference numerals indicate like elements throughout the several views, there is shown in FIGS. 1 - 6 various views of a side panel latch according to the present invention. The latch 1 comprises two separate parts, a housing 2 and a pawl 3 , each of which is a separately molded piece.
[0049] Reference now will be made to the individual components of the latch 1 . FIGS. 7 - 9 show various views of the pawl 3 of the latch 1 . Wherein said pawl 3 comprises a locking portion 71 , and a living spring portion 4 , wherein said living portion 4 is embodied in a generally inverted U-shaped mechanism. Said pawl 3 further comprises a pair of locking pegs 5 , 6 for retaining the latch 1 in a closed position. Said locking peg 5 comprises an indentation 7 recessed on the top wall 31 of locking peg 5 . Similarly, said locking peg 6 comprises an indentation 8 recessed on the top wall 32 of locking peg 6 . Said locking peg 5 further comprises a front ramped wall 22 , a curved bottom peg portion 63 , a front straight upper wall 29 , outer side wall 24 , inner side wall 28 , and bottom wall 33 . Moreover, said locking peg 6 also further comprises a front ramped wall 23 , a curved bottom peg portion 64 , a front straight upper wall 30 , outer side wall 25 , inner side wall 27 , and bottom wall 34 .
[0050] Said locking pegs 5 , 6 are separated from each other by a space 26 , wherein said space 26 terminates at a sloped inner wall 41 , wherein a straight upper lip 42 extends upwardly from said sloped inner wall 41 . A sloped outer wall 68 is the opposite side of sloped inner wall 41 , wherein said sloped outer wall 68 joins said locking pegs 5 , 6 to the living spring portion 4 of the pawl 3 .
[0051] As best seen in FIG. 9, the bottom wall 33 of locking peg 5 comprises an indentation 35 , wherein said indentation 35 comprises a sloped back wall 37 , which is angled at the same position and at the same plane as sloped inner wall 41 . Diametrically opposed to said sloped back wall 37 is front wall 39 of indentation 35 . Similarly, the bottom wall 34 of locking peg 6 comprises an indentation 36 , wherein said indentation 35 comprises a sloped back wall 38 , which is angled at the same position and at the same plane as sloped inner wall 41 . Diametrically opposed to said sloped back wall 38 is front wall 40 of indentation 36 .
[0052] Said living spring portion 4 of said pawl 3 further comprises a curvilinear flexion portion 9 located at a position atop of said living spring portion 4 . Said living spring portion 4 further comprises a pair of generally downward sloping walls 10 , 11 extending downwardly from said curvilinear flexion portion 9 . Whereby, generally downward sloping wall 11 is diametrically opposed to sloped outer wall 68 . Generally downward sloping wall 10 comprises an outer wall 12 , an inner wall 13 , and a curved portion 19 . Whereas, generally downward sloping wall 11 comprises an outer wall 14 , an inner wall 15 , and a curved portion 20 . An open space 16 separates said downward sloping wall 10 from downward sloping wall 11 . A pair of catches 17 , 18 extend from said curved portion 19 of said living spring portion 4 , wherein a catch indent separates said catch 17 from said catch 18 .
[0053] Said curved portion 20 of said living spring portion 4 terminates at a pawl base 69 , which joins said living spring portion 4 with said locking portion 71 . Said sloped outer wall 68 terminates at a curved joining portion 70 , which terminates at said pawl base 69 , thus joining said locking portion 71 with said living spring portion 4 .
[0054] FIGS. 10 - 12 show various views of the housing 2 of the latch 1 . The housing 2 comprises a pawl recess 43 , an actuation recess 44 , a top surface 45 , a front upper lip 58 , a rear upper lip 66 a right side wall 46 , a left side wall 47 , a housing wall 48 , a pair of peg opening holes 49 , 50 , a pair of catch opening holes 51 , 52 , a base 53 , a curved base 61 , a rear catch 54 , a front catch 55 , a stop 62 , a guide 67 , and a catch stop 65 .
[0055] The housing wall 48 divides said housing 2 into two compartments, wherein one of the compartments is the pawl recess 43 , and the other compartment is the actuation recess 44 . The pawl recess 43 is adapted to receive the pawl 3 , wherein the actuation recess 44 is adapted to receive the means for actuating the pawl, such as the user's fingers (not shown). The bottom of said pawl recess 43 comprises the base 53 , and the bottom of said actuation recess 44 comprises the curved base 61 . The top surface 45 of the housing 2 is generally flat such that when said latch 1 is mounted into the assembly (shown in FIGS. 13 - 23 ), the latch 1 becomes almost flush with other parts of the assembly (such as a frame 59 and a door 60 ) with only a thickness in an amount equal to a thickness of front upper lip 58 and rear upper lip 66 extending from the surface of the panel 59 and the door 60 .
[0056] Said housing wall 48 terminates at its bottom with said pair of catch opening holes 51 , 52 . Said pair of catch opening holes 51 , 52 are adapted to accommodate catches 17 , 18 of said pawl 3 . Thus, when the pawl 3 is installed in the housing 2 , said catches 17 , 18 snap into position within catch opening holes 52 , 51 respectively.
[0057] The housing is adapted to receive the locking portion 71 of the pawl 3 also. Whereby, the peg opening holes 49 , 50 are adapted to receive the locking pegs 5 , 6 respectively. The front catch 55 is positioned such to reside within space 26 of pawl 3 once the pawl 3 is installed in the housing 2 . The front catch 55 comprises an upper sloped portion 56 and a lower sloped portion 57 . Said front catch 55 is dimensioned and configured such that when the latch 1 is mounted into the door 60 , the front catch 55 prevents said latch 1 from moving by sandwiching said door 60 in between said front catch 55 and said front upper lip 58 .
[0058] The rear catch 54 likewise keeps the latch 1 in position, and prevents the latch 1 from moving once the latch 1 is installed into the door 60 . The rear catch 54 , as best seen in FIG. 12, terminates at the catch stop 65 , thereby the door 60 is sandwiched in between the rear upper lip 66 and the catch stop 65 of said rear catch 54 . The guide 67 is included just below said rear upper lip, attached to the curved base 61 of the housing 2 .
[0059] [0059]FIG. 11 most clearly shows the stop 62 extending from the top surface 45 of the housing 2 . The stop 62 prevents the straight upper lip 42 of said pawl 3 from moving into the pawl recess 43 , thereby limiting the lateral movement of said locking pegs 5 , 6 .
[0060] FIGS. 13 - 23 show the latch 1 installed in the door 60 , and also show the frame 59 . FIGS. 13 - 17 show the latch in a neutral position, whereby the locking pegs 5 , 6 extend under the frame 59 , thereby locking the latch 1 and preventing the door 60 from opening. FIG. 16 best shows locking peg 6 extending beyond door-frame boundary 72 , wherein said boundary 72 is the demarcation line between where the frame 59 ends and the door 60 begins. Thus, once locking pegs 5 , 6 extend beyond this boundary 72 , the latch is said to be in a neutral position, and when the door is closed, the door will be locked.
[0061] FIGS. 18 - 23 show the latch in an actuated position, whereby the locking pegs 5 , 6 do not extend under the frame 59 , thereby the latch 1 is open, and thus the door 60 may swingably open outward. FIG. 19 best shows locking peg 6 extending only under the door 60 , and only up to, but not including, the door-frame boundary 72 . Thus, the door 60 is capable of being opened. Once the latch 1 is actuated, and the door 60 is opened, then the user may release the pawl, such that it returns to its neutral position, whereby the locking pegs 5 , 6 extend to their fullest lateral positions.
[0062] When the user wishes to close the door, then he or she does not have to actuate the latch 1 . Rather the user may simply slam the latch down, wherein the front ramped walls 22 , 23 of the locking pegs 5 , 6 will allow the door 60 to close. At the point of contact when the latch is being slammed shut (door 60 is being slammed shut), the frame 59 at the door-frame boundary 72 will contact the front ramped walls 22 , 23 , causing the locking pegs 5 , 6 of the pawl 3 to move laterally into a position of actuation, thereby causing the living spring portion 4 to compress, and allowing the locking pegs 5 , 6 to clear the frame 59 . Once the locking pegs 5 , 6 clear the frame 59 , and the door 60 is closed, the locking pegs 5 , 6 snap back into neutral position, whereby locking pegs 5 , 6 extend under the frame 59 , past the door-frame boundary 72 . Thus, the living spring portion 4 returns to its neutral, non-compressed position. The front upper lip 58 extends beyond the door-frame boundary 72 and over the top of the frame 59 , thereby serving to prevent inward movement of the door 60 beneath the frame 59 .
[0063] These and other advantages of the present invention will be understood upon a reading of the Summary of the Invention, the Brief Description of the Drawing Figures and the Detailed Description of the Preferred Embodiment. Other modifications may be made consistent with the spirit and scope of the invention described herein.
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A side panel slam action latch comprising a two-piece assembly embodied in a rigid housing and a relatively flexible pawl member. The flexible portion of the pawl serving to actuate the pawl from a closed position to an open position. Locking pegs extend from the pawl to lock the latch, and upon actuation of the pawl, the locking pegs retract and allow for opening and closing of the door panel, which houses the latch.
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RELATED APPLICATIONS
[0001] The application is a continuation application of prior U.S. application Ser. No. 12/568,034, filed on Sep. 28, 2009, and which claims the benefit of: (1) U.S. Provisional Application No. 61/173,355, which was filed on Apr. 28, 2009, (2) U.S. Provisional Application No. 61/166,260, which was filed on Apr. 3, 2009, and (3) U.S. Provisional Application No. 61/100,295, which was filed on Sep. 26, 2008. Each of these disclosures are herein incorporated by reference in their entirety.
BACKGROUND
[0002] Internal combustion engines contain multiple cylinders. Exhaust gas is generated when a fuel and air mixture is ignited and expanded within a cylinder to drive a piston. The exhaust gas is typically vented from the cylinders through an exhaust stroke to the atmosphere. The exhausted gas typically has a very high temperature when leaving the cylinders. In some proposed systems, the exhaust gas is delivered to a second cylinder for further expansion.
[0003] Some internal combustion engines have injected water into the same cylinder performing combustion with fuel and air intake.
[0004] There has also been a proposal for a combined engine that has a combustion cylinder mounted upstream of an expansion cylinder. The expansion cylinder receives hot exhaust gas from the combustion cylinder, and also receives a source of water that is expanded into steam by the hot exhaust gas to create further drive for a common crankshaft.
[0005] While this proposed system has good potential, there are many improvements that would make the system more practical.
SUMMARY
[0006] In features of this invention, downstream expansion cylinders are associated with a combustion cylinder to provide an overall surface area and volumetric displacement of expansion cylinders sufficient to lower the temperature of fluids associated with the combined engine to such an extent that a radiator can be eliminated in an associated vehicle, or other system.
[0007] In a separate feature, a catalytic material is placed on surfaces which will “see” the hot exhaust gases such that catalytic conversion of impurities in the gases can be achieved within the engine itself.
[0008] In yet another feature, water is recovered from a system having both a water injection expansion cylinder, and a combustion cylinder, and the recovered water is re-used for the expansion.
[0009] In yet another feature, gearing is provided between an expansion cylinder and a combustion cylinder such that the output of the combined engine is optimized, and the two cylinders do not drive the crankshaft in a one-to-one fashion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 schematically shows a first embodiment engine.
[0011] FIG. 2 is a flowchart of a basic system incorporating this invention.
[0012] FIG. 3 shows a second embodiment system.
[0013] FIG. 4 shows another potential embodiment.
[0014] FIG. 5 shows yet another embodiment.
[0015] FIG. 6 shows yet another embodiment.
[0016] FIG. 7 shows yet another embodiment.
[0017] FIG. 8 graphically shows the input versus output for exemplary systems.
[0018] FIG. 9 shows a water cooling system incorporated into this invention.
[0019] FIG. 10 shows another embodiment of the water cooling system.
[0020] FIG. 11 shows a water recovery system.
[0021] FIG. 12 shows a catalytic conversion system.
DETAILED DESCRIPTION
[0022] An engine 20 is illustrated in FIG. 1 , and incorporates combustion cylinders 32 and 34 , which are mounted adjacent to an expansion cylinder 33 . Each of the cylinders include pistons 50 , which are driven to drive a common crankshaft 52 . Although the cylinders are shown in side-by-side relationship, in practice, they will be inline such that the common crankshaft 52 is driven by each of the pistons 50 . Of course, other configurations can be used.
[0023] The cylinders 32 and 34 are combustion cylinders and are shown having spark plugs 44 . However, other combustion cylinders which do not require spark plugs would also benefit from the teachings of this application.
[0024] As shown, intake valves 40 control the flow of air and fuel into the cylinders 32 , 34 , in some engine types, such as Diesel, the fuel may be directly injected into the cylinders. The combined air and fuel is compressed, ignited, and exhausted through exhaust valves 42 into an associated exhaust line 46 . The cylinders 32 and 34 may be four-stroke cylinders, and will operate as known, at least as described to this point.
[0025] Inlet valves 48 on the expansion cylinder 33 alternately operate in sync with the alternating operation of valves 42 and receive the hot, high pressure exhaust from the exhaust lines 46 . The gases at least partially drive the larger displacement piston 50 associated with the expansion cylinder 33 in a two-stroke fashion. As known, the cylinders 32 and 34 will be out of phase by 360°. Cylinder 33 has a final exhaust valve not shown.
[0026] A water injection system 70 takes water from a source of water 71 and injects it into the engine at any one of several possible locations. As shown, the water may be injected through line 72 into the exhaust line 46 . Water may be injected through line 74 to the top of the cylinder of the expansion cylinder 33 . The water may be injected as shown at 76 into the top of cylinders 32 , 34 . If injected into the cylinders 32 and 34 , it is preferred that the water be injected late in an exhaust cycle.
[0027] The water injection and metering can be performed in much the same way as high pressure fuel injection is commonly performed in a diesel engine, for example. The injection of water is estimated to be at a rate of 1 to 2 times the rate of fuel consumption for a gasoline engine. The water can be injected into the expansion cylinder 33 head at the time exhaust gases are being communicated to the expansion cylinder 33 . Owing to a finite thermal absorption and vaporization delay for the heat of the ignition to vaporize the injected water, it may be beneficial in some cases to move the injection of the water forward in the process, into the exhaust passage 46 , or into one of the cylinders as described above at 76 . In the case of injecting the water into one of the combustion cylinders 32 or 34 , this should occur at a mature point of the power-stroke, 160 degrees-175 degrees, past top dead center, for example.
[0028] Valves V are shown for controlling the flow of the injection of the water, and may be controlled by an overall engine control, in a manner that would be apparent to a worker of skill in this art.
[0029] While cam shafts are shown for controlling the operation of the several cylinder valves, other means of valve timing, such as electronic valve controls may be utilized.
[0030] Fuel and air fed combustion cylinders 32 and 34 may fire nominally at 0 degrees and 360 degrees of rotation respectively. The cylinders 32 , 34 alternate intake and power strokes while the expansion cylinder 33 executes an exhaust stroke. During the exhaust stroke, gases exit the expansion cylinder through a valve, not shown. Each cylinder 32 , 34 contributes torque to a crankshaft 52 through the power-stroke. The combustion cylinders 32 , 34 alternate compression and exhaust strokes while the second cylinder 33 is executing a power stroke. In the power stroke, the piston 50 in the expansion cylinder is driven by expansion of the steam and exhaust gas. The expansion cylinder 33 expands the exhausted gas of the cylinder 32 beginning nominally at 180 degrees of rotation and then, after completing an exhaust stroke, the cylinder 33 alternately further expands the emission from the cylinder 34 beginning nominally at 540 degrees of rotation, in a two-stroke fashion.
[0031] In one example, displacement of the expansion cylinder 33 is four times that of the cylinders 32 or 34 (the displacements of the cylinder 32 and cylinder 34 may be nominally the same). Accordingly, the second cylinder 33 contributes significant positive torque to the crankshaft 52 .
[0032] Oil pans 60 associated with the combustion cylinders 32 and 34 are shown. The sump 62 of the expansion cylinder may be sealed from the oil pans 60 , and their combustion cylinders 32 and 34 , such that water can collect, as will be described below.
[0033] FIG. 2 is a flowchart which briefly describes the above-described system. First, an exhaust gas is produced in a combustion cylinder. This exhaust gas is expanded along with water via a water injection process. The expanded gas creates a pressure front which drives the expansion cylinder piston. The expanded gas is substantially cooled before discharge. Thermal transfer between cylinders maintains the working temperature of the first cylinder.
[0034] FIG. 3 shows a top down view of an embodiment 100 with combustion cylinders 132 associated with an expansion cylinder 133 . An exhaust passage 146 connects cylinders 132 to cylinder 133 . Additional downstream expansion cylinders 102 are provided, to provide a multi-stage cascade. As shown, the exhaust 104 from the expansion cylinder 133 delivers expanded exhaust gas into the cylinders 102 .
[0035] In general, the use of the several expansion cylinders provides that the total surface area of expansion cylinders is sufficiently large that all, or the great majority, of the generated heat and energy can be recaptured prior to being exhausted to atmosphere. In this manner, the invention may allow the elimination of the radiator.
[0036] The pistons of the outer expansion cylinders 102 can have the same rotational phase as the four-stroke cylinders 132 , respectively, and could be 180 degrees out of phase with the central two-stroke expansion cylinder 133 . In this example, the need for ever larger displacement through a cascade is provided by having the combined displacement of the outer cylinders 102 be substantially greater than the displacement of the central cylinder 133 , while the interior configuration may operate as previously described.
[0037] The example outer cylinders 102 , may have bores that are larger than the central cylinder 133 by a factor of √{square root over (2)}, causing a combined displacement four times larger than the first cascade in the central cylinder 133 .
[0038] In one example, two outer cylinders 102 receive the exhausted gas. In other examples, cascading continues from cylinder 133 to a single downstream cylinder. The direction and number of cylinders receiving the exhaust is not limited. It is desirable that each downstream, or cascaded, cylinder has larger displacement than the cylinder providing exhaust gases.
[0039] Water injection can occur through a water injection line 108 which is shown injecting water into the first stage expansion cylinder at 107 , and the second stage expansion cylinders 102 at 106 . As will be described below, the several stage cascading as disclosed in the FIG. 3 embodiment allows the exhaust gas and water to be lowered to a very low temperature, and for a great majority of the potential energy generated by the combustion process to be captured as useful energy, rather than lost as wasted energy.
[0040] As seen in FIG. 4 , four-stroke combustion cylinder 202 drives a crankshaft 280 , and a two-stroke expansion cylinder 204 that is powered by exhaust and water as described above, drives a shaft 279 . An intermediate two-to-one gear reduction 206 may be a planetary transmission. The gear reduction 206 may be any type of coaxial gear reduction. One example would be a complex planetary gearing system, including more than one planetary gear set to eventually provide a 2:1 reduction, however, other gear reductions can be utilized.
[0041] The crankshafts of the two cylinders 202 , 204 are mechanically synchronized in this embodiment through gear reduction 206 , such that the 360 degree operation of cylinder 204 is effectively expanded to 720 degrees to match the operation of four-stroke cylinder 202 . The example arrangement has the heavier reciprocating mass of the two-stroke, secondary power-stroke expansion cylinder 204 now reciprocating at half speed of the lighter, but faster, fuel and air fed four-stroke cylinder 202 . The example arrangement has appreciable opportunity for additional thermal-to-mechanical energy extraction through a single cascade.
[0042] As shown in FIG. 5 , an alternative system may use a dual gearing 208 and 210 that achieves the two-to-one gear reduction from the expansion cylinder crankshaft 212 to the crankshaft 214 . This may allow the larger displacement requirement of expansion cylinder 204 to be achieved by a longer stroke or a combination of a larger bore and a larger stroke.
[0043] The FIG. 4 or 5 arrangements can be used in combined multiple groupings. Also, water injection would preferably be used with these embodiments.
[0044] Referring to FIG. 6 , two two-stroke secondary power-stroke expansion cylinders 502 can be coupled to one four-stroke combustion cylinder 504 in various different formations. In such formations, the four-stroke cylinder 504 supplies the exhausted gas required for secondary expansion alternately to the two two-stroke secondary power-stroke expansion cylinders 502 . In general, the expansion cylinders 502 are driven such that they operate at one-fourth the speed of the piston for the combustion cylinder 504 , and are out of phase with each other. A gear reduction 581 is shown schematically connecting their crank portions 580 . Typically, the three crank portions will be non-coaxial, although this is not a limitation on this portion of the inventive concepts.
[0045] For each two-stroke expansion cylinder 502 , there are four quarter-exhaust strokes and four quarter-power strokes for each one thousand fourteen hundred forty degree cycle, or two four-stroke cycles. The first two-stroke cylinder 502 is offset from the second two-stroke cylinder 502 , such that when one is in an exhaust stroke, the other is in a power stroke. This allows the four-stroke 504 to feed one two-stroke at a time.
[0046] Again, a water supply source 535 may inject water through a line 537 into an exhaust line 19 connecting the single combustion cylinder 504 to each of the expansion cylinders 502 . Of course, as with the earlier embodiments, any number of other locations for water injection may also be utilized.
[0047] Again, an oil pan 583 may be maintained separate from water sumps 579 .
[0048] An embodiment 700 is illustrated in FIG. 7 . Combustion cylinders 706 generate hot exhaust gas which is passed downstream to a first expansion cylinders 704 , and then to second expansion cylinders 702 . Each expansion cylinder 704 and 702 has a progressively greater displacement and effective surface area compared to the combustion chambers 706 . As shown, gearing 714 drives gear 712 to achieve a first gear reduction, and gear 712 drives a second gear 713 . The gear reduction between gears 714 and 712 is selected such that there is a 2:1 step-down. Gears 712 and 713 provide a 1:1 drive arrangement.
[0049] The operation of the system may generally be as described above. Again, water injection is shown schematically through a source 710 into the expansion cylinder 702 and 704 . Again, water pans 703 may be maintained separate from oil pan 701 . However, here oil pan 701 services both combustion cylinders 706 and hot first expansion cylinders 704 while only the second, and final in this example, expansion cylinders 703 are cool enough to be serviced by water pans 703 .
[0050] In other examples, N-two-stroke expansion cylinders can be coupled to M positioned four-stroke cylinders to create multiple cascades. Here, N and M are arbitrary numbers greater than or equal to 1.
[0051] In a similar example, one four-stroke cylinder could feed N-number of two-stroke, secondary-power-stroke expansion cylinders, where N is an arbitrary but generally even number. This creates an adaptable system configuration where the engine wastes little to no heat and the final exhaust temperature is brought to an exceptionally low value. Therefore, the only system energy exit is through the performance of mechanical work. This may allow the elimination of the radiator for an associated vehicle.
[0052] High-temperature, water-lubricated polymeric materials may be used in critical places within the construction of the second cascade, such as the outer cylinders 702 . For example, the second cascade can have a dense, Teflon-like coating on the interior of the cylinder wall. The type of coating is not limited here. The connecting rod bearings similarly may use dense Teflon for bearing material, although similarly, not limited. The second cascade may be intentionally driven beyond the condensation point, such that water lubrication is available, as water condensation is captured within the engine for re-use. The heat loss by the final exhaust can be managed in this manner down to a negligible level.
[0053] FIG. 8 shows a schematic summary of the overall operation of the several above disclosed embodiments. Air and fuel is brought into the system and combusted. Thermal insulation is preferably provided about the engine such that there is minimal heat loss to the environment from the engine. The energy output in a typical engine includes mechanical work, such as driving a crankshaft. The inventive systems are designed to maximize this output.
[0054] The prior art systems typically lose heat to a radiator. The inventive systems attempt to minimize any heat to a radiator, and in fact to eliminate any need for a radiator, as will be explained below.
[0055] Prior systems lose heat to the exhaust. The inventive systems aim to reduce the temperature of the exhaust to such an extent that there will be little or no heat loss at this location. The same is true with heat loss to convection.
[0056] FIG. 9 shows an embodiment 900 of a water cooling system which may be maintained as a closed circuit, and separate from the water injection. In the water cooling system 900 , cascade or expansion cylinders 902 are adjacent to a combustion cylinder 904 . A water jacket 906 surrounds each of the cylinders. As can be appreciated, fuel, air and water injection lines, consistent with the above-described embodiments, would also extend through the water jacket in actual embodiments. A return line 908 returns water from the water jacket 906 through a flow control valve 910 , and to a water pump 912 which recirculates the water. The pump 912 is arranged such that it pulls the water from the vicinity of the combustion cylinder 904 , over the expansion cylinders 902 . The heat which is captured in the water by cooling a combustion cylinder 904 is partially captured to heat the expansion cylinders 902 . An optional heat exchanger 951 may be included which utilizes remaining heat in the return line 908 to heat water in the water injection line 950 heading for the expansion cylinders. However, this heat exchanger is optional, and need not be utilized.
[0057] The main requirement for the cooling water jacket to cool the combustion cylinders, and then heat the expansion cylinders, is that the temperature of the cascade or expansion cylinders needs to be lower than the working temperature of the liquid coolant. This requirement can be facilitated by increasing the operating pressure, and therefore temperature, of the liquid coolant system. A temperature sensor 914 can be set such that it will send a signal to a control 916 to allow higher temperatures if such are desirable. While water may be used as the cooling fluid, any number of other coolants may be utilized.
[0058] The temperature sensor 914 may provide information back to the control 916 which controls the water valve 910 to ensure adequate water supply to maintain the temperatures as desired.
[0059] In addition, the control 916 may be an ignition control input which can control the timing of the ignition for the combustion cylinder 904 . In a standard engine, it would not be desirable to slow ignition timing based upon undue temperatures in the system, as this will simply reduce the overall produced useful energy. However, given that the present invention captures a much greater percentage of the useful energy, slowing of ignition timing can be utilized while still capturing sufficient power through the subsequent cascades. Thus, the control 916 may be programmed with an algorithm that will identify an undesirably high temperature at the temperature sensor 914 , and slow ignition timing. In this manner, the overall system can be more likely to capture a greater percentage of the useful energy created by combustion.
[0060] In general, the control 916 can modulate the ignition timing to achieve tight control over the temperature of the combustion cylinder. A sensed over-temperature condition can be rectified by retarding the ignition timing by one to twenty-five degrees of crank rotation, for example. The exact amount may depend on the size and abruptness of the overall temperature condition. This will transfer some of the heat load to the expansion cylinders, where it can contribute to useful work. This retardation of ignition timing will also reduce the peak temperature and pressure for the benefit of reduction of pollutant generation.
[0061] FIG. 10 shows another embodiment 920 wherein the expansion cylinders 902 are positioned to be separated by a thin wall 922 from the combustion cylinder 904 . All of the cylinders may be formed in a single block 921 . This embodiment may be a passive transfer system that does not include a pump. The liquid jacket 919 surrounding the block 921 may be a sealed container containing any vapor or liquid fluid having good heat transfer properties.
[0062] Any number of other ways of transferring heat from the combustion chambers to the expansion chambers may be incorporated into this invention.
[0063] With either of the FIGS. 9 and 10 embodiments, the very hot combustion cylinder 904 transfers heat energy to the cascade cylinders 902 . The cascade cylinders 902 benefit from this additional heat, as it increases the temperature of the injected water environment to produce additional steam, and allows the recapture of this heat energy.
[0064] By capturing and transferring the heat in this manner, the system is able to reduce the exhaust gas and water from the most downstream cascade cylinder to such an extent that no radiator may be necessary.
[0065] FIG. 11 shows a water recovery system 930 . When utilized in a system, and in particular in a mobile vehicle system, the source of water to be injected must be contained within a tank 936 associated with the vehicle. The system 930 has a cylinder 932 provided with a piston 933 driven to expand from exhaust and water expansion, as are found in any of the embodiments described above. An exhaust 938 of this system passes through a water scrubber or water trap 940 which returns water through a line 941 , and passes exhaust gases downstream through a line 943 . More than one phase of water scrubbing may be provided. Eventually, the exhaust gas may reach a muffler 942 . Muffler 942 may be provided with yet another scrubber 944 which passes the final exhaust gas through line 945 to atmosphere, and returns water through yet another water return line 941 to an overall water return line 952 . Scrubber 944 may be included within the muffler housing or attached downstream.
[0066] The piston 933 is provided with piston seals 948 which may provide a loose seal with an internal surface 950 of the expansion cylinder 932 . The amount of “clearance” is exaggerated in this Figure to show the fact of the clearance. The crankcase 946 for the expansion cylinder may be separated from oil such that the expansion cylinder components are lubricated only by this water. The water-containing crankcase may be similar to the case 62 in FIG. 1 , 579 in FIG. 6 , 703 in FIG. 7 or any other arrangement. The use of the loose fit will ensure that a good deal of steam which has been expanded to the point of condensation in the cylinder 932 will fall to the crankcase 946 , and be returned through water return line 952 to the water tank 936 . A pump 937 may drive the water to the injection line 934 back into the cylinder 932 .
[0067] The recovery of the water from the crankcase 946 may be only necessary on the most downstream expansion cylinder, however, it can optionally be utilized on more expansion cylinders than simply the most downstream. A water scrubber 939 is shown on the line leading from the crankcase 946 , and may remove an exhaust gas 929 , similar to the above-described embodiment.
[0068] The water scrubbers may be known water traps, and in particular may be chilled or cold water traps of known design. Further, the crankcase drain line can be combined into the exhaust line 938 such that a single set of water scrubbers may be utilized to achieve the above-described features.
[0069] By having this detailed water recovery system, the present invention ensures that the source of water will be largely recycled, and that an unduly large water tank will not be necessary.
[0070] Across the embodiments, expansion cylinders may be provided in sufficient numbers, such that the final exhaust may be brought to a low temperature, say below 500° F., and in a preferred embodiment, at or below 212° F. When surrounded with high levels of an external insulation, this low temperature exhaust becomes almost entirely the sole source of thermal efficiency loss in steady-state operation. The frictional “loss” of internal moving components also becomes captured within the system so as to be either converted as part of the useful mechanical output or to otherwise be a component of this modest final exhaust emission. These engines may achieve steady-state thermal-to-mechanical efficiencies that are in the range of 94-96%.
[0071] Steady-state operation may be characterized by the following rough thermal budget. In a current engine, say a radiator would account for 25% of the thermal budget, while in the described examples accounting for essentially 0%. In a current engine, conduction/convection might account for 25% of the thermal budget whereas in the described examples accounting could be approximately 1-2% of the thermal budget. In a current engine, exhaust may account for 25% of the thermal budget whereas in the described examples may account for approximately 2-3% of the thermal budget. Further, in a current engine, mechanical extraction may account for 25% of the thermal budget where as in the described examples might account for approximately 95% of the thermal budget.
[0072] It is believed that there could be back pressure due to the injection of the exhaust gas that could complicate the breathing induction of the combustion cylinders. By injecting water into a cascade cylinder head space after the exhaust gas communication is complete (as an example at the 50% cut-off point for a 2:1 crank synchronization; at the 25% cut-off point for a 4:1 crank synchronization, there will be less back pressure for the exhaust cycle to work into. As another example, should there be a 8:1 speed reduction on the cranks, the above can occur at the 12.5% cut-off point. This will improve the breathing of the combustion cylinder to improve power density, while still allowing the establishment of a steam vaporization pressure front.
[0073] Other ways of addressing this breathing concern can be utilized. As an example, the combustion four-stroke cylinder can be RAM charged or super-charged. The combustion cylinder can be of a particularly long stroke, as in a diesel cycle. The combustion cylinder can employ at Atkinson cycle, resulting in a very low cylinder pressure by the end of its power-stroke. The displacement ratio of the expansion cylinder to the combustion cylinder can be designed to be higher than described above. The combustion cylinder can be replaced with a split-cycle pair of cylinders, as has been proposed by Scuderi Motors. Water can be injected into the cascade cylinder head space after the exhaust communication is complete, as described above. Any of these methods of simplifying the breathing/back pressure issue can be utilized.
[0074] Referring to FIG. 12 , in one example, components have their surface materials chosen so as to catalyze certain desirable reactions for the benefit of reduced exhaust emissions. A surface within a cylinder assembly could include an inner lining 611 made of a particular surface material designed to have the same catalyzation effect as a catalytic converter. In one embodiment, the cylinder is an expansion cylinder, and more preferably, plural expansion cylinders such as are described above. The surface materials may include but are not limited to: platinum, palladium, rhodium, cerium, iron, and manganese. This example takes advantage of both the enhanced residence time as well as the enhanced surface area, as both increase with an increase in cascaded cylinders, to catalyze reactions that are presently catalyzed in a separate external catalytic converter subsequently eliminating or reducing the need for the converter. As shown in FIG. 12 , a first cylinder 604 is associated with a downstream cylinder 606 , which is larger. Pistons 608 move within the cylinders 604 and 606 . Cylinder head 619 receives valves 617 . An exhaust connection 610 connects the two. The lining material 611 can be formed on any, or all, of the interior of the cylinders, the pistons, and the cylinder heads, the valves and in the exhaust passage 610 . The catalytic materials can be used on any surface, e.g., fluid flow paths, etc., that will “see” the hot exhaust gas.
[0075] In another example, different surface materials for internal environments become required as the final exhaust emission is likely to be much cooler than presently-in-use four-stroke engines, and possibly much lower than desirable for best catalytic reaction kinetics.
[0076] Generally, surfaces exposed to the hot gaseous fluid flow may have thermal insulation on the outside of the arrangement, or hot interior-surfaces and structural components may be made of thermally low conductive material. Another alternative would be to maximize heat loss prevention and use a low conductive material that is additionally thermally insulated on the outside. For example, the piston tops have substantial surface area exposed to hot gases, while their bottoms are exposed to crankcase oil. The heat-of-combustion to the displacement volume above the piston top may be confined for thermal-to-mechanical extraction and to avoid heating the crankcase oil. Therefore piston tops made of, for example, a thermally dead ceramic, or ones with a lightweight, crankcase-compatible insulation on the underside, or both, may be used. Another example would be pistons made of normal material, clad bonded with a thermally dead ceramic top surface. Similar concepts could be applied to the valves and valve tops, the hot gaseous-exposed interior-surface of the cylinder-head, the intake passages and exhaust passages from one cylinder to the next in the several above embodiments. This creates a continuous expansion motor with heat energy preserved through all the hot gaseous fluid flow and confined to mechanical energy extraction by the various, and now cascaded, power strokes.
[0077] Ultimately, water vapor condensation concerns may limit the minimum desirable final exhaust temperature, but only after a far greater thermal-to-mechanical extraction has been accomplished relative to currently-in-use internal combustions engines. Distilled water may be sufficient for the disclosed purpose, but tap water, or, tap water with a de-calcification/de-crystallization agent alone may also be sufficient. Further, the fuel can carry de-calcification/de-crystallization capability.
[0078] Many operating environments will be cold enough to freeze the water, causing a potential problem. However, this is likely manageable using, for example, flexible storage containers that can accommodate freeze expansion or similar technology. The final exhaust can also be used to melt the stored water over the longer operational term and a small high temperature thermal extraction channel from the 4 -stroke cylinders can be used to melt water initially for the near term start-up. One other possibility is an electric melt device which is most cost-effective for initial, temporary use.
[0079] The combustion cylinder can be made up of, but not limited to, one or more of the following types of fuel and air cylinders including aspirated, fuel injected, carbureted, turbo-charged, super-charged, ram-charged, or any combination of these. The fuel can include, but is not limited to, the use of fuels including gasoline, diesel, propane, natural gas, alcohol, hydrogen, kerosene, or any other fuel known in the art.
[0080] In another example, the combustion cylinders may include an Otto four-stroke cylinder, Atkinson four-stroke cylinder, Diesel four-stroke cylinder, or any other known four-stroke cylinder.
[0081] While the expansion cylinders have generally been described as two-stroke cylinders, the invention would extend to four-stroke cylinder assemblies.
[0082] 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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Downstream expansion cylinders are associated with a combustion cylinder such that an overall surface area and displacement volume of the expansion cylinder is sufficient to lower the temperature of fluids associated with the combined engine to such an extent that a radiator can be eliminated in an associated vehicle, or other system. In a separate feature, a catalytic material is placed on surfaces which will “see” the hot exhaust gases such that catalytic conversion of impurities in the gases can be achieved within the engine itself. In yet another feature, water is recovered from a system having both a water injection expansion cylinder, and a combustion cylinder, and the recovered water is re-used for the expansion. In yet another feature, gearing is provided between the expansion cylinder and a combustion cylinder such that the output of the combined engine is optimized, and the two cylinders do not drive the crankshafts in a one-to-one fashion. In another feature the combustion cylinder's ignition timing is delayed (retarded) to manage thermal control of said combustion cylinder between it and a subsequent expansion cylinder or cylinders.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a non-provisional application claiming priority from Chinese Patent Application No. CN201110452621.X, filed Dec. 30, 2011, and incorporated herein by reference in its entirety.
FIELD OF THE DISCLOSURE
The present invention relates to an electric tool for weeding the lawn in a garden, and more particularly to an electric weeder.
BACKGROUND OF RELATED ART
In the prior art, the traditional methods for weeding the lawn include manual weeding and spraying herbicide by a chemical method. In order to alleviate work intensity of manual weeding and enhance the efficiency of weeding, some digging tools are designed for weeding, which contain manual machine and hand-held electric weeder. However, these digging tools almost have some disadvantages, for example, the weeds cannot be eradicated, or some large pits may be remained in the ground after weeding, so that the initial greensward and then the lawn are damaged.
The prior electric weeder commonly includes a diving device, a transmission device, an operating handle, a connecting device, a removing device, and a working head. This weeder has a relatively long and incompact overall structure, and the removing structure is too complex for the user to operate conveniently; moreover, the handle structure of the machine is not designed according to the characteristic of the weeding operation, that is, it is not designed by cooperating the weeding operation with the ergonomics application, resulting in that the user may get tired easily when operating the machine and it is time and labor consuming.
SUMMARY
The object of the present invention is to provide an electric weeder which can exactly weed the lawn with little damage, and it includes a simple weeds-removing mechanism and can enhance the efficiency of weeds-removing. In addition, the present invention provides an operating method for weeding, and also provides an optimal size range of the external appearance which incorporates with the external shape of the machine, with such size range, the weeder enables the force direction of the hand of the operator approximately pass through the working head of the machine during the operation so as to obtain an object of labor saving.
In order to resolve the above technical problem, the present invention provides an electric weeder, including a driving device, a transmission shaft, a working head, a sleeve, a removable handle, and a removing plate. The driving device is disposed in the housing, a transmission shaft is rotatively driven by the driving device, the working head is connected to and rotated along with the transmission shaft. The sleeve is mounted around the transmission shaft and connected to the housing; the removable handle is configured to move along the transmission shaft, and one end of the removable handle is disposed around the sleeve; the removing plate is disposed on the other end of the removable handle and configured to move along with the removable handle, and the removing plate is provided with a through portion allowing the working head to pass through.
The invention also provides an electric weeder, including a housing, a driving device, a working head, and a removable handle. The driving device is disposed in a housing, and including an axis line. The working head is connected to the axis line and driven by the driving device; the removable handle moves relative to the working head and the housing, and wherein on end of the removing handle is movably connected to the housing, the other end includes a removing plate, and the removing plate includes a through portion being passed through by the working head.
The beneficial effects of the present invention are as follows:
The electric weeder of the present invention can exactly weed the lawn with little damage, and the weeds-removing mechanism is simple and practical. The removable handle is directly cooperated with the weeds-removing mechanism in the axial direction such that the weeds and soils can be pushed out by the removable handle without any connections that are usually arranged between the conventional operating handle and the weeds-removing mechanism, which makes the overall structure of the machine more simple and effectively reduces the overall length of the machine; the removable handle can remove the weeds automatically so as to lower the work intensity of the operator and increase the efficiency of weeding. Contrary to the conventional machine, the design for the external structure of the present invention advantageously cooperates with the ergonomics. As a result, the operator can operate the machine with labor and time saving, and it is not easy to feel tired upon holding the machine, thus the work efficiency can be enhanced greatly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a structural view of an electric weeder according to one embodiment of the present invention;
FIG. 2 is a structural view of the electric weeder of FIG. 1 during removing the weeds;
FIG. 3 is a structural view of an electric weeder according to another embodiment of the present invention;
FIG. 4 is a structural view of the electric weeder of FIG. 3 during removing the weeds; and
FIG. 5 is a structural view of the external structure of the electric weeder according to the present invention.
DETAILED DESCRIPTION
Next, the present invention will be described with reference to the drawings. The following embodiments are only used to explain the technical solutions of the present invention more clearly, and cannot be used to restrict the protection scope of the present invention.
The First Embodiment
As shown in FIGS. 1 and 2 , the electric weeder includes a power portion, a transmission portion, and a weeds-removing mechanism. A driving device (not shown) is disposed in a main housing 7 and used to drive a transmission shaft 2 to rotate. A sleeve 8 which is mounted around the transmission shaft 2 is connected to the lower end of the main housing 7 , and in other embodiments, the sleeve 8 may be integrated with the main housing 7 . One end of the sleeve 8 is connected to the main housing 7 , and the other end is a flange 81 protruding from the body of the sleeve. Generally, the working head of the machine includes several rods 1 arranged on the same circumference, wherein the ends of the rods are all connected to the transmission shaft 2 . The driving device may be similar to that of an electric drilling machine, an electric screwdriver, or other electric driving devices.
A removable handle 5 is disposed around the periphery of the transmission shaft 2 and can slide along the transmission shaft 2 . The removable handle 5 is configured as cylinder shape, wherein one end thereof is a hook 52 which is slidably mounted around the outer wall of the sleeve 8 and limited by the flange 81 on the lower end of the sleeve 8 so as to slide without disengaging from the outer wall of the sleeve 8 , and the other end thereof is closed by a removing plate 3 . The removing plate 3 is provided with several through portions for allowing several rods 1 to pass through, respectively. In addition, a circular limiting plate 51 is connected to the inner wall of the removable handle 5 , and the distance between the limiting plate 51 and the hood 52 is larger than the height of the sleeve 8 , so that the flange 81 on the sleeve 8 is always located between the limiting plate 51 and the hook 52 . The circular structure formed in the limiting plate 51 will not interfere with the movement of the transmission shaft 2 , and the transmission shaft 2 can freely rotate or shuttle axially therein.
The weeds-removing mechanism further includes a reset element which is generally a reset spring 4 mounted around the transmission shaft 2 . The transmission shaft 2 is provided with a shoulder 21 , thus, one end of the reset spring 4 may be abutted against a limiting plate 51 in the removable handle 5 , and the other end of the reset spring 4 may be abutted against the shoulder 21 on the transmission shaft 2 , so that the reset spring 4 is held by the limiting plate 51 and the shoulder 21 .
When using the electric weeder to weed the lawn, as shown in FIG. 1 , the center of the circumference surrounded by the rods 1 should be aligned with the roots of the weeds and the machine should be inserted into the ground with an appropriate depth. Subsequently, the switch 6 is activated to control the start of the driving device in the main housing 7 , and then the transmission shaft 2 is driven by the driving device and rotated to bring the rods 1 to rotate, such that the roots of the weeds and the soil can be wrapped on the rods 1 under the action of the rotation of the rods 1 . At this time, the operator may turn off the switch 6 and pull the rods 1 together with the weeds and soil out of the ground. In this way, only a very small pit may be remained on the ground which was occupied by the weeds.
When removing the weeds, the operator may push the removable handle 5 downwards, and the removable handle 5 may force the removing plate 3 to move downwards, as shown in FIG. 2 . With the guidance of the through portions on the removing plate, the removing plate 3 may move downwards along the rods 1 to remove out the soil wrapped on the rods 1 and the weeds in the soil. Since the reset spring 4 abuts against the shoulder on the transmission shaft 2 at one end and keeps static relative to the transmission shaft 2 , the limiting plate 51 in the removable handle 5 will compress the reset spring 4 when the removable handle 5 moves downwards in the axial direction of the sleeve 8 . During the movement of the removable handle 5 , the extreme position thereof is limited by locking the hook 52 at one end of the removable handle 5 on the flange 81 of the sleeve 8 .
When the soil wrapped on the rods 1 and the weeds in the soil have been removed out by pushing the removable handle 5 downwards, if the operator releases the removable handle 5 , the weeds-removing mechanism will restore to its initial position automatically under the action of the reset force of the reset spring 4 .
The Second Embodiment
As shown in FIGS. 3 and 4 , the present embodiment is improved on the basis of the first embodiment.
In the present embodiment, the removing plate 3 is moveably connected to the removable handle 5 . The removing plate 3 is provided with a circle of protruding flange 31 at the outer periphery, and the end of the removable handle 5 is correspondingly provided with a circle of groove 53 for accommodating the protruding flange 31 of the removing plate 3 , so that the removing plate 3 can be freely rotated in the removable handle 5 . With such configuration, when the removable handle 5 is pushed to slide up and down in the axial direction, the removing plate 3 can also be forced to slide. Moreover, the structure of the sleeve 8 in the first embodiment is changed in the present embodiment. Specifically, a sleeve 9 which is mounted around the transmission shaft 2 is connected to the lower end of the main housing 7 , and in other embodiments, the sleeve 9 may be integrated with the main housing 7 . One end of the sleeve 9 is connected to the main housing 7 , and the other end is connected with a protruding spring limiting block 10 . In addition, a circular limiting plate 51 is connected to the inner wall of the removable handle 5 , wherein the distance between the limiting plate 51 and the hook 52 is smaller than the height of the sleeve 9 , and the spring limiting block 10 connected to the sleeve 9 can stop the downward movement of the limiting plate 51 so as to restrict the removable handle 5 to slide in a certain range.
The reset spring 4 is mounted around the sleeve 9 and the two ends of the reset spring 4 respectively abuts against the hook 52 of the removable handle 5 and the spring limiting block 10 so that it can be held by the hook 52 of the removable handle 5 and the spring limiting block 10 .
Other structures are similar to those in the first embodiment.
When weeding the lawn, the driving device is turned on by the switch 6 to drive the transmission shaft 2 to be rotated, and the rods 1 can be rotated along with the transmission shaft 2 to force the removing plate 3 mounted around the rods 1 to be rotated. Since the removing plate 3 is movably connected with the removable handle 5 , the removable handle 5 would not rotate when the removing plate 3 is rotated with the rods 1 . Moreover, the reset spring 4 is mounted around the sleeve 9 , so that the reset spring 4 , the sleeve 9 , and the spring limiting block 10 would not rotate with the transmission shaft 2 when the transmission 2 is rotated. In this way, it can prevent the removable handle 5 , the reset spring 4 , the sleeve 9 and other elements rotating as the rotation of the transmission shaft 2 , thereby reducing the output power of the driving device.
The Third Embodiment
In the first embodiment, as shown in FIGS. 1 and 2 , during the normal state (i.e. the electric weeder is not operated); the removable handle 5 is located at a position near to the top portion under the action of the reset spring 4 . Every time the machine is operated, it is necessary to overcome the elastic force of the reset spring to manually push the removable handle 5 downwards to a position near to the bottom portion so as to force the removing plate 3 to remove the weeds.
In the present embodiment, the position of the reset spring 4 in the first embodiment is changed, that is, the reset spring is mounted around the transmission shaft and held by the limiting plate 51 and the flange 81 .
During the natural state (i.e. the electric weeder is not operated), the removable handle 5 is located at a position near to the bottom portion under the action of the reset spring, namely, a position shown in FIG. 2 . When the operator uses the machine to remove the weeds, the center of the circumference surrounded by the rods 1 should be aligned with the roots of the weeds and the machine should be inserted into the ground with an appropriate depth, the removing plate 3 will be pushed to move upwards due to the resistance of the soil, and then the insertion force can overcome the elastic force of the reset spring. As a result, as shown in FIG. 1 , the removable handle 5 is pushed to a position near to the top portion (in other embodiments, the removable handle can also be lifted upwards by hand firstly), and the reset spring is compressed. As such, if the operator activates the switch 6 , the rods 1 will rotate along with the transmission shaft 2 , so that the roots of the weeds and the soil can be wrapped on the rods 1 under the action of the rotation of the rods 1 . At this time, the operator may pull the rods 1 together with the weeds and soil out of the ground, and the removable handle can be automatically restored to remove the weeds under the action of the reset force of the reset spring. That is to say, it is not necessary to manually push the removable handle 5 and can obtain the automatic weeds-removing.
The Fourth Embodiment
In the second embodiment, as shown in FIGS. 3 and 4 , during the natural state (i.e. the electric weeder is not operated), the removable handle 5 is located at a position near to the top portion under the action of the reset spring 4 . Every time the machine is operated, it is necessary to overcome the elastic force of the reset spring to manually push the removable handle 5 downwards to a position near to the bottom portion so as to force the removing plate 3 to remove the weeds.
In the present embodiment, the position of the reset spring 4 in the second embodiment is changed, that is, the reset spring 4 is mounted around the sleeve 9 which is located at the outside of the removable handle, and the reset spring 4 is held by the hook 52 of the removable handle 5 and the shoulder formed at the joint between the housing and the sleeve.
During the natural state (i.e. the electric weeder is not operated), the removable handle 5 is located at a position near to the bottom portion under the action of the reset spring, namely, a position shown in FIG. 4 . When the operator uses the machine to remove the weeds, the center of the circumference surrounded by the rods 1 should be aligned with the roots of the weeds and the machine should be inserted into the ground with an appropriate depth, the removing plate 3 will be pushed to move upwards due to the resistance of the soil, and then the insertion force can overcome the elastic force of the reset spring. As a result, as shown in FIG. 3 , the removable handle 5 is pushed to a position near to the top portion (in other embodiments, the removable handle can also be lifted upwards by hand firstly), and the reset spring is compressed. As such, if the operator activates the switch 6 , the rods 1 will rotate along with the transmission shaft 2 , so that the roots of the weeds and the soil can be wrapped on the rods 1 under the action of the rotation of the rods 1 . At this time, the operator may pull the rods 1 together with the weeds and soil out of the ground, and the removable handle can be automatically restored to remove the weeds under the action of the reset force of the reset spring. That is to say, it is can obtain the automatic weeds-removing without manually pushing the removable handle 5 .
The Fifth Embodiment
As shown in FIG. 5 , the external dimensions of the electric weeder in the above embodiments are optimally designed.
The optimal lengths of the electric weeder are as follows:
1. The length L 1 of the hand-held portion of the main housing 7 of the electric weeder is 50<L 1 ≦170 mm, so that a space for receiving the fingers is provided when the operator holds the handle;
2. The length L 2 of the removable handle 5 is 60<L 2 ≦200 mm, so that a space for operating with fingers is provided when the operator holds the removable handle to remove the weeds;
3. The width L 3 for holding on the main housing 7 is 30<L 3 ≦60 mm, so that the main housing is adapted to be hand-held by the operator and a space for operating with fingers is provided;
4. The overall length of the machine is L 0 =L 1 +L 2 +L 3 /2>50+60+15=125 mm, L 0 =L 1 +L 2 +L 3 /2≦170+200+30=400 mm, and thus 125<L 0 ≦400 mm;
5. The effective working length of the pin is 20<L 4 ≦50 mm, and L 4 /L 0 =0.05˜0.4.
The optimal diameter ratios of the electric weeder are as follows:
1. The diameter Φa of the circumference along which the rods 1 are arranged is Φ8 mm≦Φa≦Φ20 mm. With this range, the pit remained on the ground after weeding has a suitable diameter, and the resistance during the rotation of the pin is also suitable since the larger the diameter is, the greater the resistance is.
2. The diameter Φb of the end of the removable handle 5 is Φ12≦Φb≦Φ30 mm. With this range, the operator can easily observe the roots of the weeds, and the end of the removable handle would not obstruct the vision of the operator.
3. The diameter Φc of the hand-held portion of the handle is Φ25≦Φc≦Φ45 mm. With this range, the handle is suitable to be held by hand.
4. In order to make the operator observe that the working head is exactly located at the roots of the weeds during the operation, the ratio of the working portion is Φa /Φb=0.5˜1.
The above contents are the preferred embodiments of the present invention. It should be noted that without departing the technical principle of the present invention, the person skilled in the art may make some modifications and changes to the present invention, which may be considered as a part of the protection scope of the present invention.
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An electric weeder, including a housing, a driving device, a working head, and a removable handle. The driving device is disposed in a housing, and including an axis line. The working head is connected to the axis line and driven by the driving device; the removable handle moves relative to the working head and the housing, and wherein on end of the removing handle is movably connected to the housing, the other end includes a removing plate, and the removing plate includes a through portion being passed through by the working head. The electric weeder of the present invention can exactly weed the lawn with little damage, the overall structure of the machine is more simple to effectively reduce the overall length of the machine; the removable handle can remove the weeds automatically to lower the work intensity and increase the weeding efficiency.
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BACKGROUND OF THE INVENTION
a) Field of the Invention
The present invention relates to a variable magnification viewfinder optical system to be used in cameras, etc., and more specifically to a variable magnification viewfinder optical system suited for use in 35 mm lens shutter cameras.
b) Description of the Prior Art
In the recent years, there have been proposed numerous 35 mm lens shutter cameras which are adapted to be used at two selectable focal lengths. For such cameras having two selectable focal lengths, it is convenient for confirming actual photographing field angles on finders to compose finders so as to permit varying magnifications thereof in conjunction with the selection of focal lengths of the photographic lens systems. For providing this convenience, there have already been proposed a variety of finder optical systems which permit varying magnifications thereof. For example, Japanese Preliminary Patent Publication No. Sho 60-166934 proposed an inverted Galileo finder comprising a negative objective lens component and a positive eyepiece lens component arranged in the order from the object side, and adapted to permit varying magnification of the finder by replacing said negative objective lens component with another objective lens component which is composed of a positive lens element and a negative lens element arranged in the order from the object side.
Further, Japanese Preliminary Patent Publication No. Sho 61-87122 proposed a finder optical system comprising, in the order from the object side, a fixed lens component having a positive refractive power as a whole, a negative movable lens component and a fixed lens component having a positive refractive power as a whole, and adapted to vary focal length of the finder by moving said negative movable lens component forward and backward along the optical axis.
Furthermore, Japanese Preliminary Patent Publication No. Sho 63-129312 proposed an inverted Galileo finder which comprises, in the order from the object side, a negative objective lens component composed of two negative lens elements and a positive fixed eyepiece lens component, and is adapted a to vary magnification thereof by placing one of the two negative lens elements out of the effective optical path of the finder and moving the other negative lens element toward the eyepiece lens component along the optical axis.
Japanese Preliminary Patent Publication No. Sho 61-77820 proposed a finder optical system which comprises an objective lens component designed as a negative lens component consisting of a lens element having a positive refractive power and a lens element having a negative refractive power including at least one lens element made of a transparent elastic material, and an eyepiece lens component designed as a positive lens component, and is adapted to vary magnification thereof by deforming the transparent elastic material lens element so as to vary the refractive power of the objective lens component as a whole.
Japanese Preliminary Patent Publication No. Sho 61-221720 proposed a finder optical system which comprises an objective lens component and an eyepiece lens component each composed of a single lens element made of a transparent elastic material, and is adapted to vary magnification thereof by deforming the lens elements so as to vary the refractive powers thereof while maintaining a certain definite relationship therebetween.
Japanese Preliminary Patent Publication No. Sho 62-56918 proposed a finder optical system which comprises lens elements including ones designed as liquid crystal lens elements and is adapted to vary magnification thereof by moving some of the lens elements other than the liquid crystal lens elements in accordance with variation of the refractive powers of the liquid crystal lens elements.
Out of the conventional examples described above, however, each of the finder optical systems which is adapted to vary the magnification thereof by moving a portion of the optical system has a composition to move one or more lens elements to vary the refractive power of the objective lens component as a whole, and therefore has disadvantages such as the mechanism for varying the magnification is complicated and requires high precision, and cost is increased for manufacturing the finder optical system in practice since the number of parts is increased, thus requiring tedious assembly procedures and delicate adjustment. Speaking concretely, it is necessary to compose the magnification varying mechanism in such a manner that the movable lens elements are located with correct distances reserved to the other fixed lens elements before and after the movements and with no eccentricities with regard to the optical axis. Otherwise, it will be difficult to attain to the design performance such as the magnification, dioptric power, field ratio, and image legibility. Further, the finder optical systems which are adapted to vary magnifications thereof by using the lens elements having the variable refractive powers, out of the conventional examples described above, control the refractive powers by deforming the external shapes of the lens elements having the variable refractive powers under physical forces of driving devices and must control the driving devices with high accuracy so as to obtain stable deformation degrees, thereby having disadvantages that the driving mechanisms and the control circuits therefor are complicated and that costs are enhanced for manufacturing the finder optical systems in practice.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a variable magnification viewfinder optical system which has a simplified mechanism for varying magnification thereof and can be manufactured at a reduced cost.
Another object of the present invention is to provide a variable magnification viewfinder optical system which is easily capable of attaining to design performance such as magnification, field ratio and image legibility with high precision.
The variable magnification viewfinder optical system according to the present invention comprises a polarizing element for allowing incident light to emerge as linearly polarized light, an objective optical system comprising a first lens component having refractive power that varies depending on the oscillating direction of the incident light, and an eyepiece optical system comprising a second lens component having variable refractive power, and is adapted to change the oscillating direction of said polarizing element from one plane to another plane perpendicular to the first.
Since the variable magnification viewfinder optical system according to the present invention comprises no movable lens elements, it permits positioning the lens elements thereof with high precision, thereby attaining a precise design performance with a simple mechanism, reducing the number of the required parts as well as the number of assembling and adjusting steps, and lowering manufacturing cost. Speaking more concretely, the present invention makes it possible to easily attain to a predetermined design performance of the viewfinder optical system in respect of magnification, dioptric power, field ratio, and image legibility since the element varied for changing magnification of the optical system has no relation to the relative distance between the lens components of the optical system or eccentricity with regard to the optical axis thereof. Further, since magnification of the viewfinder optical system according to the present invention is changed by turning the polarizing element by an angle of 90° or ON-OFF control of an application voltage to a liquid crystal layer, an alternative control is sufficient for the magnification change, thereby making it possible to simplify the driving mechanism and the control circuit, and to lower manufacturing cost for the viewfinder optical system.
These and other objects as well as the features and the advantages of the present invention will becomes apparent from the following detailed description of the preferred embodiments when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A and FIG. 1B are diagrams illustrating the principal to change polarizing direction of light by turning a polarizing plate around an optical axis;
FIG. 2A and FIG. 2B are diagrams illustrating the principle to change polarizing direction of light by eletrically driving a TN liquid crystal layer arranged after the polarizing plate;
FIG. 3 is a sectional view illustrating the composition of an Embodiment 1 of the variable magnification viewfinder optical system according to the present invention; and
FIG. 4 is a sectional view illustrating the composition of an Embodiment 2 of the variable magnification viewfinder optical system according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Prior to detailed description of the present invention with reference to the preferred embodiments, the lens elements having variable refractive powers, the control method for changing polarizing direction of light by 90° and fundamental composition of the viewfinder optical system according to the present invention will be explained below.
The lens elements having variable refractive powers (birefringent lens components) can be made of crystalline materials such as liquid crystal and calcite.
Further, the variable magnification viewfinder optical system is to be controlled so as to change polarizing direction of light by 90° by a certain adequate method, for example, one of the two methods described below. One method is to turn a polarizing plate 1 around an optical axis as illustrated in FIG. 1A and FIG. 1B. The other method is to arrange a TN (twist nematic) liquid crystal layer 2 after the polarizing plate 1 as illustrated in FIG. 2A and FIG. 2B, and turn the polarizing direction by electrically driving the TN liquid crystal layer 2.
Since the viewfinder optical system has a fundamental composition wherein the optical system can be divided into the objective lens component and the eyepiece lens component, the following formula must nearly establish among refractive power φ O of the objective lens component, refractive power φ E of the eyepiece lens component and paraxial distance e between these lens components:
1/φ.sub.O +1/φ.sub.E =e
Hence, when the refractive power φ O of the objective lens component, the refractive power φ E of the eyepiece lens component and angular magnifications γ at the tele position and the wide position respectively are represented by reference symbols φ OT , φ ET , γ T and φ OW , φ EW , γ W respectively, the following formulas will establish;
1/φ.sub.OW +1/φ.sub.EW =1/φ.sub.OT +1/φ.sub.ET =e
γ.sub.W =-φ.sub.EW /φ.sub.OW, γ.sub.T =-φ.sub.ET /φ.sub.OT
When an image point is located between the rear principal point of the objective lens component and the front principal point of the eyepiece lens component (when φ O and φ E have the same sign), it is therefore necessary to select a composition of the optical system wherein φ O is strong (has a large absolute value) and φ E is weak for the wide position, and another composition wherein φ O is weak and φ E is strong for the tele position. When an image point is located before the rear principal point of the objective lens component (in case of γ<1) (when φ O and φ E have the signs different from one another), it is necessary to select a composition wherein both φ O and φ E are strong for the wide position, and another composition wherein both φ O and φ E are weak for the tele position. In a case where an image point is located after the front principal point of the eyepiece lens component (in case of γ>1)(when φ O and φ E have the signs different from each other), it is necessary to select a composition wherein both φ O and φ E are weak for the wide position and another composition wherein both φ O and φ E are strong for the tele position. It will therefore be understood that the combination of φ O and φ E having the same sign allows to obtain a magnification variation ratio γ T /γ W which is higher than that available with the combinations of φ O and φ E having the signs different from each other when the selected refractive power φ O or φ Z varies at the same rate.
In the description of the above formula, the expression "must nearly establish" is selected since strict establishment of the above formula will be at zero diopter, which is set slightly on the negative side in most cases of practical designs. Even when diopter is not set at zero, e has a value different only slightly from that determined by formula.
Further, each of the refractive power φ O of the objective lens component and the refractive power φ E of the eyepiece lens component is divided, by the paraxial theory, into a portion which varies depending on polarizing direction and another portion which is constant independent of the polarizing direction. When the variable portions of the refractive powers of the objective lens component and the eyepiece lens component are represented by φ OV and φ EV respectively, and the invariable portions of the refractive powers of the objective lens component and the eyepiece lens component are designated by φ OC and φ EC respectively, φ O and φ E can be expressed as follows:
φ.sub.O =φ.sub.OC +φ.sub.OV,
φ.sub.E =φ.sub.EC +φ.sub.EV
Now, assuming that φ OC =φ EC =O, the angular magnification at the tele position and that at the wide position of the optical system are in the following relationship:
γ.sub.W ·γ.sub.T =1
However, φ OC =φ OE =O is inconvenient since viewfinder optical system should generally be so designed as to have magnification levels lower than 1x at both the tele position and the wide position taking the visual performance of photographers into consideration. By selecting adequate values other than 0 for φ OC and φ OE , it is possible to obtain γ W ·γ T ≠1, or optionally set γ W and γ T matched with the visual performance of photographers. For this purpose, it is practically important to impart refractive powers(φ OC ≠0, φ OE ≠0) to the lens elements other than the birefringent lens elements for obtaining γ W ·γ T ≠1 independently of the refractive index of the liquid crystal.
As for indications for the range finding frame and visual field frame, two types are conceivable. In one of these types, apparent sizes of these indications are kept constant regardless of magnification change by composing the optical system in such a manner that the polarized direction of the rays to be used for the indications is always kept constant independently of the polarized direction of the rays used in the visual field system. In the other type, the optical system is composed taking into consideration the variation of apparent sizes of the indications to be caused by the magnification change.
Now, the present invention will be described more detailedly with reference to the preferred embodiments illustrated in the accompanying drawings.
In the following description on the magnification change in the embodiments, thickness of each lens component is ignored since refractive power is almost never influenced by the thickness.
Embodiment 1
FIG. 3 shows a keplerian variable magnification viewfinder optical system preferred as the Embodiment 1, wherein a polarizing plate 11, an objective lens component 12, an erect prism 13 and eyepiece lens component 14 are arranged in the order from the object side, and an eye 15 is located at the position of the exit pupil of the eyepiece lens component 14. The polarizing plate 11 is mounted on a polarizing plate driving device 16 so as to be rotatable 90° around the optical axis. Further, both the objective lens component 12 and the eyepiece lens component 14 are designed as cemented doublets each of which is used as a case and consists of lens elements made of a material having low double refraction and having a liquid crystal lens layer interposed therebetween. Though the surfaces located before and after the liquid crystal layers are traced as spherical surfaces for representing the refractive powers of the surfaces in FIG. 3, these surfaces are designed actually as Fresnel lens surfaces. Radii of curvature on the surfaces of the lens elements arranged in the objective lens component 12 are r 3 , r 4 , r 5 and r 6 in the order from the object side, whereas radii of curvature on the surfaces of the lens elements arranged in the eyepiece lens component 14 are r 9 , r 10 , r 11 and r 12 in the order from the object side. Each of the cases of the liquid crystal lens elements has a refractive index n C (=1.51633), and the liquid crystal has a refractive index n. (=1.7) for the extraordinary ray and refractive index n. (=1.5) for the ordinary ray. The liquid crystal lens elements arranged in the objective lens component 12 and the eyepiece lens component 14 are oriented so as to be perpendicular to each other, and the polarizing plate 11 is set in such a direction that the ray having been transmitted through the polarizing plate 11 is always polarized as the ordinary ray at a wide position and as the extraordinary ray at the tele position for the liquid crystal lens element arranged in the objective lens component. The reason for selecting the perpendicular orientation between the liquid crystal lens elements will be described later together with the refractive power distribution in the Embodiment 1.
Since the liquid crystal used in the Embodiment 1 has an Abbe's number of approximately 30 which is smaller than that of the plastic material selected for the cases, the cases are used as positive lens elements and the liquid crystal lens elements are used as negative lens elements. Furthermore, since φ O and φ E have the same sign, the optical system is composed in such a manner that the objective lens component 12 has strong power and the eyepiece lens component 14 has weak power at the wide position, and vice versa at the tele position. Speaking more concretely, the optical system is composed in such a manner that the negative power of the liquid crystal lens element of the objective lens component 12 is weakened and the negative power of the liquid crystal lens element of the eyepiece lens component 14 is strengthened at the wide position, and vice versa at the tele position, whereby the liquid crystal lens element of the objective lens component 12 has a low refractive index and the liquid crystal lens element of the eyepiece lens component 14 has a high refractive index at the wide position, and vice versa at the tele position. In addition, though each of the lens components has a slightly positive refractive power when the liquid crystal is set at the lower refractive index thereof which has an absolute value smaller than that of the refractive power of the case in the Embodiment 1, the fundamental concept described above is applicable to the Embodiment 1.
Now, description will be made on the variation of megnification.
First, a ray coming from an object passes through the polarizing plate 11, the objective lens component 12, the erect prism 13 and the eyepiece lens component 14 in this order, and then is incident on the eye 15.
At the wide position, the ray having been transmitted through the polarizing plate 11 is polarized in such a direction as to be the ordinary ray for the liquid crystal lens element in the objective lens component 12 and the extraordinary ray for the liquid crystal lens element in the eyepiece lens component 14. Accordingly, the power of the objective lens component 12, that of the eyepiece lens component 14 and the angular magnification of the optical system at the wide position are calculated by the following formulae:
φ.sub.OW =(n.sub.C -1)(1/r.sub.3 -1/r.sub.6)+(n.sub.O -1) (1/r.sub.4 -1/r.sub.5)
φ.sub.EW =(n.sub.C -1)(1/r.sub.9 -1/r.sub.12)+(n.sub.e -1) (1/r.sub.10 -1/r.sub.11)
γ.sub.W =-φ.sub.EW /φ.sub.OW
The refractive powers and angular magnification calculated by using the above formulae are φ OW =0.03982, φ EW =0.01877 and γ W =-0.4712. On the other hand, accurate calculations taking thickness into consideration will give refractive powers of φ OW =0.03927 and φ EW =0.0186 as well as an angular magnification γ W =-0.47517 at a dioptric power of -1 diopter.
At the tele position where the polarizing plate 11 is rotated 90° around the optical axis from the direction thereof at the wide position by a polarizing plate drive means 16, the ray having passed through the polarizing plate 11 is polarized so as to be the extraordinary ray for the liquid crystal lens element arranged in the objective lens component 12 and the ordinary ray for the liquid crystal lens element in the eyepiece lens component 14. Therefore, the refractive power of the objective lens component 12, that of the eyepiece lens component 14, and the angular magnification of the optical system are as calculated by the following formulae:
φ.sub.OT =(n.sub.C -1)(1/r.sub.3 -1/r.sub.6)+(n.sub.C -1) (1/r.sub.4 -1/r.sub.5)
φ.sub.ET =(n.sub.C -1)(1/r.sub.9 -1/r.sub.12)+(n.sub.O -1) (1/r.sub.10 -1/r.sub.11)
γ.sub.T =-φ.sub.ET /φ.sub.OT
The refractive powers and angular magnification calculated by using the above formulae are φ OT =0.02638, φ ET =0.02543 and γ T =-0.9640 respectively. On the other hand, accurate calculations taking thickness into consideration will give powers of φ OT =0.02619 and φ ET =0.02521 as well as an angular magnification γ T =-0.97530 at a dioptric power of -1 diopter. In the Embodiment 1, the surfaces of the liquid crystal lens elements are designed as Fresnel type for thinning the liquid crystal layers. Further, the polarizing plate 11 may be of various types.
It is generally necessary for liquid crystal lens elements to select thin liquid crystal layers in order to stabilize orientations of liquid crystal molecules. In case of a liquid crystal lens element having a large effective diameter, a method to design at least the front or rear surface of the liquid crystal layer as a Fresnel lens surface for thinning the layer. When a liquid crystal lens element has a small effective diameter, in contrast, either of the surfaces thereof need not be designed as a Fresnel surface but can be designed as a spherical surface. In the latter case, the spherical surface can be manufactured more easily and provides more legible images in the visual field.
Numerical data of the Embodiment 1 will be listed in the table shown below:
______________________________________ RefractiveSurface Radius of Distance between index orNo. curvature (r) surfaces (d) material (n)______________________________________1 ∞ 1 Polarizing plate2 ∞ 1 Air3 26.6662 1 1.516334 -29.7573 0.001 Liquid crystal layer [n.sub.e = 1.7] [n.sub.o = 1.5]5 29.7573 1 1.516336 -26.6662 12.77 Air7 ∞ 75 1.516338 ∞ 12.77 Air9 39.8927 1 1.5163310 -60.0280 0.01 Liquid crystal layer [n.sub.o = 1.5] [n.sub.e = 1.7]11 60.0280 1 1.5163312 -43.2329 15 Air13 ∞ (Pupil location)______________________________________ Angular magnification: γ τ = -0.97530, γ w = -0.47517 Dioptric power: -1 diopter
Embodiment 2
FIG. 4 illustrates an inverted Galilean variable magnification viewfinder optical system preferred as the Embodiment 2, wherein a polarizing plate 11, a TN liquid crystal layer 17, an objective lens component 12 and an eyepiece lens component 14 are arranged in the order from the object side, and an eye 15 is located at the position of the exit pupil of the eyepiece lens component 14. The polarizing plate 11 is fixed, whereas the TN liquid crystal layer 17 is to be controlled by ON-OFF operation of a voltage application means 18. Speaking more concretely, the TN liquid crystal layer 17 is set so as to transmit the linearly polarized light coming from the polarizing plate 11 while turning the plane of polarization thereof by 90° when the voltage application means 18 is turned OFF, and transmit said light without turning the plane of polarization thereof when the voltage application means 18 is turned ON. Further, both the objective lens component 12 and the eyepiece lens component 14 are designed as cemented doublets each of which is used as a case and composed of lens elements made of a material having low double refraction and cemented with a calcite lens element interposed therebetween. In the Embodiment 2, radii of curvature on the surfaces of the lens elements composing the objective lens component are r 3 , r 4 , r 5 and r 6 in the order from the object side, radii of curvature on the surfaces of the lens elements composing the eyepiece lens components are r 7 , r 8 , r 9 and n O in the order from the object side, refractive index of the lens elements arranged before and after the calcite lens element is n C (=1.51633), refractive index of the calcite lens element for the extraordinary ray is n O (=1.48640), and refractive index of the calcite lens element for the ordinary ray is n O (=1.65835). In this case, the optical axis of the crystal of the calcite in the objective lens component 12 is parallel with that of the calcite in the eyepiece lens component 14, and the polarizing plate 11 is set in such a direction that the ray having passed through the polarizing plate 11 is polarized so as to be the extraordinary ray for the calcite lens element arranged in the objective lens component 12 at the wide position and the ordinary ray for the calcite lens element at the tele position. The reason for setting the optical axes of the crystals so as to be parallel with each other will be described later together with the fundamental concept of the power distribution selected for the Embodiment 2. As is seen from FIG. 4, in the object lens component 12 the lens elements arranged before and after calcite lens element are designed as negative lens elements and the calcite lens element is designed as a positive lens element whereas, in the eyepiece lens component 14, the lens elements arranged before and after the calcite lens element are designed as positive lens elements and the calcite lens element is designed as a negative lens element. Since calcite has an Abbe's number which is nearly equal to that of the glass material selected for the lens elements arranged before and after the calcite lens elements, the above-described lens designs have been selected not for correction of chromatic aberrations but for protecting calcite which is an easily damaged material. Further, since φ O and φ E have signs different from each other, the viewfinder optical system is composed in such a manner that both the objective lens component 12 and the eyepiece lens component 14 have strong powers at the wide position, and vice versa at the tele position. In other words, the viewfinder optical system is composed in such a manner that the positive power of the calcite lens element arranged in the objective lens component 12 and the negative power of the calcite lens element arranged in the eyepiece lens component 14 are weakened at the wide position, and vice versa at the tele position, whereby the calcite lens elements arranged in the objective lens component 12 and the eyepiece lens component 14 have the lower refractive powers at the wide position, and vice versa at the tele position.
Now, description will be made on variation of magnification of the Embodiment 2.
First, the ray coming from an object is transmitted through the polarizing plate 11, the TN liquid crystal layer 17, the objective lens component 12 and the eyepiece lens component 14 in this order, and then falls on the eye 15.
At the wide position, no voltage is applied to the TN liquid crystal layer 17 from the voltage application means 18, the ray having passed through the polarizing plate 11 is polarized in such a direction that the ray having passed through the TN liquid crystal layer 17 is polarized in the direction perpendicular to the direction of polarization at the incidence stage, and the extraordinary ray for both the calcite lens elements arranged in the objective lens component 12 and the eyepiece lens component 14. Therefore, the refractive power of the objective lens component 12, that of the eyepiece lens component 14 and the angular magnification of the viewfinder optical system at the wide position are calculated as follows:
φ.sub.OW =(n.sub.C -1)(1/r.sub.3 -1/r.sub.6)+(n.sub.O -1) (1/r.sub.4 -1/r.sub.5)
φ.sub.EW =(n.sub.C -1)(1/r.sub.7 -1/r.sub.10)+(n.sub.O -1) (1/r.sub.8 -1/r.sub.9)
γ.sub.W =-φ.sub.EW /φ.sub.OW
The above formulae give the refractive powers of the lens components and the angular magnification of the viewfinder optical system as φ OW -0.03967, φ EW =0.02050 and γ W =0.5168 respectively. On the other hands, accurate calculations taking thickness of the lens components into consideration will give refractive powers of φ OW =-0.04045 and φ EW =0.02019 as well as an angular magnification of γ W =0.52385 at a dioptric power of -1 diopter.
At the tele position, a voltage is applied to the TN liquid crystal layer 17 from the voltage application means 18, and the polarized direction of the ray having passed through the polarizing plate 11 remains unchanged even after transmission through the TN liquid crystal layer 17 so that the ray becomes the ordinary ray for both the calcite lens elements arranged in the objective lens component 12 and the eyepiece lens component 14. Therefore, the refractive power of the objective lens component 12, that of the eyepiece lens component 14 and the angular magnification of the finder optical system at the tele position are calculated as follows:
φ.sub.OT =(n.sub.C -1)(1/r.sub.3 -1/r.sub.6)+(n.sub.O -1) (1/r.sub.4 -1/r.sub.5)
φ.sub.ET =(n.sub.C -1)(1/r.sub.7 -1/r.sub.10)+(n.sub.O -1) (1/r.sub.8 -1/r.sub.9)
γ.sub.T =-φ.sub.ET /φ.sub.TO
The above calculations give the refractive powers and the angular magnification as φ OT =-0.01271, φ ET =0.00889 and γ T =0.6995. On the other hand, accurate calculations taking thickness of the lens components into consideration will give refractive powers of φ OT =31 0.01270 and φ ET =0.08892 as well as an angular magnification of γ T =0.77873 at a dioptric power of -1 diopter.
Though the crystalline materials such as calcite used in the Embodiment 2 are expensive, these materials are more excellent in performance such as stabilities of refractive indices and double refraction as well as clarities than the liquid crystal lenses, and therefore assure higher legibility of image in viewfinders. Further, though each of the lens components is designed as a cemented doublet in the Embodiment 2, it is possible to divide the lens elements thereof as required for correction of aberrations and compose the lens component of a large number of lens elements.
Numerical data of the Embodiment 2 are listed in the following table:
______________________________________ RefractiveSurface Radius of Distance between index orNo. curvature surfaces (d) material (n)______________________________________1 ∞ 1 Polarizing plate and TN liquid crystal layer2 ∞ 1 Air3 -29.5273 0.5 1.516334 12.7584 2 Calcite [n.sub.e = 1.48640] [n.sub.o = 1.65835]5 -12.7584 0.5 1.516336 22.5273 20 Air7 54.8589 2 1.516338 -29.6233 0.5 Calcite [n.sub.e = 1.48640] [n.sub.o = 1.65835]9 29.6233 2 1.5163310 -56.9470 15 Air11 ∞ (Pupil location)______________________________________ Angular magnification γ τ = 0.77873 γ w = 0.52385 Dioptric power: -1 diopter
In the Embodiments 1 and 2, the polarizing element 11 may be arranged between the objective lens component 12 and the eyepiece lens component 14 or after the eyepiece lens component 14, as shown by chain lines in FIGS. 3 and 4.
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The variable magnification viewfinder optical system comprises a polarizing element allowing the light incident thereon to emerge as a linearly polarized light, an objective optical system comprising a first lens component having refractive power variable dependently on the oscillating direction of the incident light, an eyepiece optical system comprising a second lens component having variable refractive power and a switching device capable of changing the oscillating direction of said polarizing element from one to another perpendicular to each other. This viewfinder optical system is capable of easily attaining to design performance thereof such as magnification, dioptric power, field ratio and image legibility, and permits simplifying composition thereof and lowering manufacturing cost therefor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to bearing take-up apparatus, and more particularly relates to such a take-up apparatus that is quickly, easily and safely assembled.
2. Description of the Prior Art
U.S. Pat. No. 1,571,009 which issued to Holzer on Jan. 26, 1926 discloses a bearing take-up apparatus having a base with upstanding end walls rigid therewith and a cover which cooperates with the base to define a guideway which slidably receives a bearing that journals one end of a shaft. The bearing is adjusted longitudinally of the guideway by an adjusting screw which is threaded in one of the end walls and is rotatably received in abutting engagement with the bearing housing.
Another bearing take-up apparatus which is not patented but has been manufactured by the assignee of the present invention for several years, includes a V-shaped cover having end brackets secured thereto and projecting downwardly therefrom. A threaded take-up screw is inserted through holes in the cover end brackets and has two bearing advancing nuts threaded on and positioned within the end brackets, and also has two nuts rigidly secured to the ends of the screw and positioned externally of the end plates. When assembling the take-up screw in the cover end brackets, the cover is inverted and held in a fixture. A bearing is then inverted and is placed in sliding engagement on the lower edges of the cover. The bearing has nut engaging cavities therein which are fitted over the bearing advancing nuts. A take-up frame base is then inverted and is placed in sliding engagement with the bottom of the bearing housing, which base is then bolted to the cover end brackets. The completed prior art bearing take-up frame is then removed from the fixture and is inverted to upright position thereby completing the assembly operation of the prior art device.
SUMMARY OF THE INVENTION
The bearing take-up apparatus of the present invention includes a base having spaced upstanding end walls rigidly secured thereto. A bearing housing is slidably mounted on the base between the end walls and has cavities on its upper surface. A threaded take-up screw mechanism includes a threaded rod with bearing advancing nuts screwed on the rod and positioned to be received in the bearing cavities. Washers near the outer ends of the rod and screw anchoring nuts are rigidly secured to both ends of the rod. The screw mechanism is lowered upon the upper surface of the end plates with the anchoring nuts and washers overhanging the end walls and with the bearing advancing nuts received within the bearing cavities for adjusting the bearing longitudinally of the base. An inverted V-shaped cover having slotted end brackets is then lowered over the screw and the brackets are then bolted to the end walls.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of the bearing take-up apparatus of the present invention with parts of the cover being cut away, and the near wall of a portion of the bearing housing being cut away to show one of the cavities in section and with the remainder of the bearing housing being shown in phantom.
FIG. 2 is a plan of FIG. 1 with parts of the cover being removed.
FIG. 3 is an end elevation with portions broken away, looking in the direction of arrows 3--3 of FIG. 1.
FIG. 4 is a pictorial view of a portion of a bearing take-up apparatus to better illustrate the manner of assembling the several components of the bearing take-up apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A bearing take-up apparatus 10 (FIGS. 1-4) of the present invention is directed to an arrangement of components which permits a much faster method of assembling the several components than was possible with similar prior art take-up assemblies. After the take-up apparatus has been assembled, it will be apparent that the ultimate use of the take-up apparatus is the same as the prior art apparatus; that is, to tension belts or chains trained around pulleys or the like that are secured to a shaft journaled in two side-by-side bearing take-up apparatus.
The bearing take-up apparatus 10 in general comprises a base or base frame 12, a bearing housing 14, a threaded adjusting or take-up screw mechanism 16, and a cover 18 secured to the base frame 12.
More particularly, the base frame 12 comprises an inverted fabricated channel 20 having inwardly turned end portions 22. Bolt holes 24 are formed in the upper surface 26 of the channel 20 and are aligned with semi-cylindrical slots 28 in the end portions 22 for receiving bolts (not shown) or the like which rigidly secure the base frame to a supporting surface when placed in operation.
In the preferred embodiment, the length of the base lies within the range of about 28.5-56.5 inches (72-144 cm) to provide at least four different sizes of take-up apparatus providing bearing adjustment lengths of 12, 18, 24 and 30 inches (31, 45.5, 60 and 76 cm). When the three layer bases are used, one or more reinforcing straps 30 (FIGS. 1 and 2) are welded across the sides of the base to stiffen the same.
The base frame 12 also includes a pair of end walls 32 which are rigidly secured to the end portions of the channel 20. Each end wall 32 is generally U-shaped and includes a transverse plate 34 having a pair of gussets or side walls 36 bent outwardly therefrom with the lower edges of plate 34 and the gussets 36 welded to the upper surface and side walls, respectively, of the base frame 12. Pairs of apertures 38, which are preferably square aperatures to receive the heads of square neck bolts 40, are formed in each gusset 36. The upper surface 42 of each transverse plate 34 supports one overlapping end portion of the take-up screw mechanism 16 and is preferably flat as best shown in FIG. 4, although it will be understood that the upper surface may be provided with a depressed concave arcuate portion to cradle the screw mechanism 16 if desired.
The bearing housing 14 is a well known commercial item and includes a bearing unit, such as a ball bearing, a roller bearing, or babbitted bearing unit. The bearing housing 14 includes upper and lower ears 44 which slidably maintain the bearing housing in position between the base frame 12 and the cover 18. The upper surface of the bearing housing is also provided with abutment surfaces which define cavities 46 that receive portions of the take-up screw mechanism 16.
The take-up screw mechanism 16 comprises a threaded rod or adjustment screw 50 of proper length having a pair of square bearing advancing nuts 52 screwed thereon, a pair of washers 54, and a pair of hexagonal nuts 56 on opposite ends portions of the screw and secured in place by split pins 58 or the like. The screw mechanism 16 is then placed on the upper surfaces 42 of the end walls 32 with the nuts 56 and washers 54 overlapping the end walls 32 and with the square nuts 52 positioned within the cavities 46 of the bearing housing 14. It will be understood that a portion of the adjusting screw 50 is received within U-shaped slots (not shown) in the walls of the cavities 46.
The cover 18 preferably comprises an angle bar 60 of proper length with its apex directed upwardly as best shown in FIGS. 3 and 4. Fabricated tabs or end brackets 62 of generally U-shaped construction each include a transverse wall 64 and side walls 66. Each transverse wall 64 includes a vertically extending open bottomed slot 68 (FIGS. 3 and 4) and a generally V-shaped upper end that is preferably welded to the associated end portion of the angle bar 60. The side walls 66 are apertured to receive the previously referred to square neck bolts 40 when the cover is lowered over the take-up screw mechanism 16 into position to be secured to the base frame 12. When fully assembled as best shown in FIGS. 1-3, the fabricated end bracket 62 of the cover are received within the associated U-shaped end walls 32 of the base frame 12 with the associated washers 54 and hexagonal nuts 56 being disposed outside of and overhanging adjacent transverse walls 34,64. Thus, when the bolts 40 are tightened, a simple, sturdy, and easily assembled bearing take-up apparatus is provided.
It will be understood that the bearing housing 14 is moved in one direction longitudinally of the base frame 12 by engaging one of the nuts 56 and rotating the screw 50 in one direction; while rotation of the screw in the opposite direction will move the bearing housing in the opposite direction.
It has been determined that the time required to assemble the above described bearing take-up mechanism 10 is about one-half that required when assembling assignee's previously described prior art mechanism. Also, the steps taken when assembling the take-up apparatus 10 is much more efficient and stable as compared to that of assembling the components when inverted thus minimizing injury to personnel when assembling the bearing take-up mechanism 10.
The steps taken when assembling the take-up apparatus 10 comprises placing the base frame 12 on a bench or the like in upright position, placing the bearing housing 14 on the base frame, spacing the square nuts 52 in positions to be received by the cavities 46 of the bearing housing 14 and then placing the take-up screw mechanism 16 onto the upper surface 42 of the end walls with the nuts 52 received in the bearing cavities 46 thus preventing the take-up screw from rolling, lowering the cover into position over the screw mechanism 16, with the screw being received by the slot 68 in the bracket 62 and with the washers 54 and hexagonal nuts 56 overlapping the wall 32, and thereafter bolting the cover end bracket 62 to the associated base end walls 32.
From the foregoing description it is apparent that an improved bearing take-up apparatus is provided which greatly minimizes assembly time and thus the cost of the apparatus yet provides a sturdy apparatus with the adjusting screw well protected from falling objects.
Although the best mode contemplated for carrying out the present invention has been herein shown and described it will be apparent that modification and variation may be made without departing from what is regarded to be the subject matter of the invention.
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A bearing take-up apparatus includes a rigid base having spaced upstanding walls between which a bearing housing having recesses in its upper surface is slidably received. A threaded screw having anchoring means rigidly secured on its ends and nuts intermediate its ends is lowered onto upper surfaces of the end walls with the nuts positioned to be received within the recesses while the anchoring means overhang the end walls. A cover is lowered over the screw and connecting means are provided for releasably connecting the cover to the end walls.
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BACKGROUND
Prior Art
[0001] The following is a tabulation of some prior art that presently appears relevant:
[0000]
U.S. Patents
Patent Number
Kind Code
Publ. Date
Patentee
4,565,579
Jan. 21, 1986
Fujioka
5,771,557
Jun. 30, 1998
Contrasto
7,308,892
B2
Jan. 18, 2007
Cockerell
8,146,309
B1
Apr. 03, 2012
Logemann
7,572,852
B1
Aug. 11, 2009
Ware
NONPATENT LITERATURE DOCUMENTS
[0000]
“Mechanical cracking of saw cut joints in concrete slabs on ground to eliminate the need for steel reinforcement”, Allen Cockerell, Concrete Slab Technology Pty Ltd
“Methods of concrete crack repair” www.theconstructor.org
“Bustar Expanding Grout Technical Page” www.demolitiontechnologies.com
“Crusting Cracks” www.indecorativeconcrete.com
“Concrete cracking. It happens. Here's how to fix it.” Kim Basham PhD, PE www.lmcc.com
[0007] There are many methods for repairing concrete where the crack goes all the way through the concrete and has a gap. This type of crack can be called an open shrinkage crack. These gaps are often left unrepaired. The crack is often less noticeable than a repair. Adding a saw cut on top of a crack will conceal a crack by making it appear to be a saw cut control joint. Longer, wider or crooked cracks that have a gap can be filled with various products to protect against water intrusion, weed control, improve load transfer and improve general appearance. Structural repairs can include epoxy to bond pieces together, steel bars installed at intervals across a crack or a combination of both. A cracked concrete section can be cut out, demolished and replaced. Full slab removal and replacement may be an option when concrete is severely degraded or an exact color match is required.
U.S. Pat. No. 4,565,579 discloses an expansive mortar composition for breaking rock and concrete. The composition is commonly used for demolition purposes. Holes are drilled into the breakable material. The expansive mortar is poured into the holes where pressure builds and breaks the concrete or rock in an irregular way. U.S. Pat. No. 5,771,557 shows a metal stitching method of repairing concrete cracks. In this method the concrete surface is patched when the crack is filled. It would be very difficult to match the color of the patch with the color of the concrete being patched. This structural repair method is used in anticipation of a full resurfacing repair. U.S. Pat. No. 7,308,892 shows a method of making the concrete crack from below the slab. This method would leave a jagged somewhat straight crack. It would require a saw cut through the middle of each crack to make them have a more finished appearance. U.S. Pat. No. 8,146,309 shows a crack inducer with a drainage channel at the base of the slab. This will create an unfinished crack at the top of the slab. U.S. Pat. No. 7,572,852 shows a patching material for fixing exposed aggregate concrete. This will require a great deal of time to get a good color match. The repaired crack is likely to reoccur in the same location if a saw cut is not installed to relieve the pressures that caused the original crack.
[0013] All the crack repair methods heretofore known suffer from a number of disadvantages:
(a) Crack fill repairs make a crack extremely noticeable by highlighting the crack. (b) Coloring the crack filler material to make an exact color match with the concrete is nearly impossible. (c) An exact color match between batches of concrete is nearly impossible. (d) Concrete is installed in uncontrolled environmental conditions that cause some of the color matching problems. (e) The difficulty of color matching concrete increases as the concrete ages. (f) Aesthetic repairs are often required to cover a visible crack repair. (g) Installing some inches of new concrete over an entire area can be done to cover the top of unsightly concrete. (h) Concrete resurfacing with ¼ to ⅜ inch of polymer modified type cement can be as expensive as four inches of new concrete. (i) Spray applied concrete resurfacing materials, colorants, colored sealers or any combination can be used on a section or an entire area to conceal a damaged surface. (j) Carpet or tile can be required to cover cracked concrete. (k) Rework of mismatched colors to improve aesthetics is time consuming and costly. (l) Concrete demolition is very labor intensive. (m) Installation of concrete is very labor intensive. (n) Installing a straight line saw cut on a crooked or bowed crack will only partially conceal the crack. (o) Saw cut repairs are limited to concealing straight cracks. (p) Saw cut repairs are limited to cracks that fall in line with the standard control joint layout. (q) Repairs may require removing a concrete section between a saw cut and a path of a jagged crack that results in the major challenges of unsightly patching and mismatching color as obstacles to a successful repair.
SUMMARY
[0031] In accordance with one embodiment a new method for concrete crack repair comprises a saw cut control joint near the crack and placing expansive mortar in the saw cut to apply pressure inside the saw cut whereby it opens the saw cut and closes the crack. The saw cut is then cleared of expansive mortar and fitted with an epoxy plug to hold the saw cut in the open position. Epoxy is placed inside the closed crack to bond both sides of the crack together. A cosmetic treatment is now possible to the top of the closed crack and caulk to the opened saw cut.
ADVANTAGES
[0032] Accordingly several advantages of one or more aspects are as follows: to provide a very tight crack, that is easy to cosmetically touch up, that increases load transfer across the crack, that develops interlocking action of aggregate particles on the face of the crack, that creates a control joint that isolates future movement, that spreads an active control joint, that transfers the width of the crack to the control joint, that is aesthetically pleasing, that is less noticeable, that will be bonded together with low viscosity epoxy, that produces the control joint that distracts the eye away from the closed crack, that eliminates the need to remove a concrete section, that eliminates the need to resurface or cover unsightly patching, that lowers the skill level required of craftsmen performing a crack repair, that can be cosmetically treated in similar ways as crusting cracks in decorative concrete, that eliminates the need to fill a crack, that eliminates caulking cracks, that reduces patching to pop outs that may have occurred along the top edge of a jagged crack, that reduces the labor required to make the repair, that can be held in place with the control joint spacer, that does not require coloring, that is aesthetically superior, that is easier to repair, that can be applied again to close the larger crack, that is economical, that increases job site profitability, that increases jobsite safety, that reduces the number of tools required to fix the job, etc.
DRAWINGS—FIGURES
[0033] FIG. 1 shows a top view example of an open shrinkage crack in a concrete slab.
[0034] FIG. 2 shows a top view of the open shrinkage crack, a dam and a saw cut that receives the expansive mortar application in a concrete slab.
[0035] FIG. 3 shows a top view of a completed repair including an expanded saw cut and a closed shrinkage crack in a concrete slab.
[0036] FIG. 4 shows a side view of a saw cut, an open shrinkage crack with the newly placed expansive mortar in a concrete slab.
[0037] FIG. 5 shows a side view of expansive mortar, expansive pressure inside the saw cut, the crack created at the bottom of the saw cut and the closed shrinkage crack in a concrete slab.
[0038] FIG. 6 shows a side view of a completed repair including a rigid spacer, caulk, expansive mortar, location of cosmetic repairs and the closed shrinkage crack in a concrete slab.
[0000]
Drawings-Reference Numerals
7
cosmetic surface repair
15
rigid spacer
8
open shrinkage crack
16
caulk
9
finished concrete slab
17
adhesive
10
saw cut
18
dam
11
wider saw cut
19
concrete piece number one
12
closed shrinkage crack
20
concrete piece number two
13
expansive mortar
21
cracked edges
14
created crack
DETAILED DESCRIPTION OF THE INVENTION
[0039] One embodiment of a crack repair method is illustrated in FIGS. 1 , 2 and 3 (top view) and FIGS. 4 , 5 and 6 (side view). The repair begins with planning the location of a saw cut 10 that balances aesthetics and close proximity to the open shrinkage crack 8 located on concrete piece number one 19 . The completed saw cut 10 should not appear askew. Create a dam 18 inside the saw cut 10 . Restrict expansive mortar 13 from any area where the saw cut 10 runs inside the open shrinkage crack 8 in order to confine pressure and not spread concrete piece number one 19 and concrete piece number two 20 apart. Expansive mortar 13 is mixed to a fluid consistency and poured into the saw cut 10 being treated adjacent the crack. The expansive pressure generated by the expansive mortar 13 will create a crack 14 at the bottom of the saw cut 10 and progresses to move one side of the saw cut 10 and simultaneously close the shrinkage crack 12 . The cracked edges 21 of concrete are held in place with the interlocking aggregate inside the closed shrinkage crack 12 , a rigid spacer 15 in the saw cut 10 and adhesive 17 in the closed shrinkage crack 12 . A cosmetic surface repair 7 is optionally made to the top of the closed shrinkage crack 12 .
Alternative Embodiments
[0040] In one embodiment, expansive mortar is used to facilitate pressure inside the saw cut. However, the pressure can be developed from any other material that can be placed inside the saw cut that develops sufficient expandable pressure to open the saw cut, such as foam, plastic, polyethylene, polypropylene, vinyl, nylon, rubber, leather, various impregnated or laminated fibrous materials, various plasticized materials, cardboard, paper, etc.
[0041] In one embodiment, the rigid spacer used to hold the control joint is made of epoxy. The rigid spacer can be of made of any other material that can be placed inside the saw cut to hold the prescribed separation and the crack tightly in place, such as cement, mortar, foam, polyethylene, polypropylene, vinyl, nylon, rubber, leather, various impregnated or laminated fibrous materials, various plasticized materials, cardboard, paper, etc.
[0042] In one embodiment, gravity fed epoxy is used as adhesive to hold the cracked concrete pieces together. The adhesive can be of any other material installed in the crack designed to bond the pieces together. The adhesive can be installed before the crack closes, after closure or both. The adhesive can have long or short set times and consist of various materials such as film, fabrics, foam, polyethylene, polypropylene, vinyl, nylon, rubber, leather, various impregnated or laminated fibrous materials, various plasticized materials, cardboard, paper, etc.
[0043] In one embodiment, the saw cut is of sufficient depth to receive the expansive mortar. The saw cut can be of varying depths. Best results are achieved when the saw cuts down to the top of the steel reinforcement in the slab. The steel will remain in place and give support across the newly formed control joint. Sometimes reinforcement steel is too high in the slab and may inadvertently be cut when installing the saw cut control joint. Consequently, the concrete is supported by the compacted base material under it and the epoxy interlocking the crack at the bottom of the saw cut.
Advantages
[0044] From the description above, a number of advantages of some embodiments of my new method for concrete crack repair become evident:
(a) The tightly closed shrinkage crack can be treated with cosmetic repairs that produce aesthetically pleasing results. (b) The tightly closed shrinkage crack can be left untouched and produce aesthetically pleasing results. (c) The expansive action of the mortar in the saw cut creates an active control joint. (d) Expansion and contraction movement of the repaired concrete slab are directed toward the new control joint. (e) Expansion and contraction movement of the repaired concrete slab are directed away from the repaired crack. (f) A saw cut control joint omitted from the original concrete installation can be added after a crack has occurred. (g) The expansive mortar does not stain the concrete surface like other materials. (h) This method does not require full resurfacing. (i) This method does not require new concrete. (j) The cracked concrete becomes the repair material. (k) The cracked concrete is an exact color match. (l) The demolition becomes unnecessary. (m)The new control joint will distract the eye and render a tight crack less noticeable. (n) The damage from striking or prying is avoided by activating the control joint with expansive mortar. (o) The pressure generated with expansive mortar is uniform inside the saw cut. (p) The pressure generated is internal and does not chip the top surface. (q) The entire crack shifts simultaneously without pinch points. (r) The repair can be done by one person.
[0063] Accordingly, the reader will see that the new method for concrete crack repair of various embodiments can be used to repair cracks easily and conveniently, can be used where a control joint should have been installed, can produce better quality repairs, is an exact color match and is economical. In addition, when cracks are repaired, the active control joint created enhances the durability of the crack repair and so reduces jobsite call backs by increasing the repair performance. Furthermore, the new method for concrete crack repair has the additional advantages in that:
It permits increased speed in repair; It permits increased quality of repair; It permits reduction in man power to make the repair; It permits using the existing concrete in the repair; It permits a new option for the repair man; It permits trial and error when selecting control joint placement; It permits increases work place safety; and It permits increases work efficiency.
[0072] Although the description above contains much specificity, these should not be construed as limiting the scope of the embodiments but merely providing illustrations of some of the several embodiments. For example, the saw cut can have various sizes and shapes; the saw cut can have various depths; the shrinkage crack can be of various shapes, sizes and angles; the expansive mortar can be of various compositions of matter; the adhesive can be of various forms of matter; the closed shrinkage crack can be partially bonded; the adhesive can be omitted in the closed shrinkage crack; the epoxy bond inside the closed crack can individually hold the piece in place; the rigid spacer can be relied upon in combination with the interlocking aggregate to keep the pieces in place; the rigid spacer can be of any form of matter; the rigid spacer can be bonded to one side of the saw cut; the rigid spacer can be bonded to neither side of the saw cut; the rigid spacer can be bonded to both sides of the saw cut; the rigid spacer can be held in place by friction; the rigid spacer can have a finished the top surface to replace the caulk; the control joint can be held open with any form of matter, etc.
[0073] Thus the scope of the embodiments should be determined by the appended claims and their legal equivalents, rather than by the examples given.
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A method for repairing cracked concrete ( 8 ) using expansive mortar ( 13 ) comprising the steps of installing a saw cut ( 10 ) next to an open shrinkage crack ( 8 ) and opening the saw cut ( 10 ) with expansive mortar ( 13 ) to create a wider saw cut ( 11 ) and shift half the saw cut ( 10 ) toward the open shrinkage crack ( 8 ) to close the shrinkage crack ( 12 ) tightly. Install a rigid spacer ( 16 ) to maintain the width of the control joint. Install adhesive ( 18 ) from the top of finished concrete slab ( 9 ) into the closed shrinkage crack ( 12 ). The surface of the finished concrete slab ( 9 ) will receive cosmetic repair ( 7 ) to the closed shrinkage crack ( 12 ) and let dry before applying sealer. Other embodiments are described as shown.
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FIELD OF THE INVENTION
This invention relates generally to a baseball pitching target functioning as a practice or training device, which returns a pitched baseball to a predetermined distance from the target, by virtue of the choice of the physical properties of three resilient structural members having a combined resilience chosen to provide that distance; and the target has a planar face which is presented to the pitcher at an obtuse angle in a narrow range; the target has no moving parts, no sensors or computing means connected thereto, has no ball collection means and is incapable of providing a score.
BACKGROUND OF INVENTION
The invention is narrowly directed to help a baseball pitcher choose and use the most basic training device rather than choosing one of numerous pitching targets which provide indicia of accuracy or scoring, or choosing a device which uses a net or a canvas attached to a rectangular frame.
Devices for scoring pitches are generally directed to fill special needs, serve a specified narrow purpose, are too complicated for use by a typical youngster bent on honing his pitching skill, and too expensive to purchase and to maintain. Most popular among passive devices which do nothing more than attempt to return, deflect or stop a ball pitched onto a target area, is a net or a canvas either held directly in a frame, usually rectangular, or by plural springs provided with a back support; preferably the ground-contacting portion of the frame is anchored to the ground by plural stakes and not free-standing.
The problem with using a net is that the velocity and direction of return of the ball is highly variable depending on how close to the frame the net is struck by the ball. The variation in the angle of return is exaggerated when the face of the net is tilted at an obtuse angle, with the result that the ball is seldom returned to the vicinity of the pitcher. Moreover, a ball striking the frame careens off unpredictably, thus jeopardizing the safety of bystanders. Though the basic, simple, net or canvas tilted at an obtuse angle could be constructed of heavy duty materials held in a rigid frame by plural springs able to withstand repeated impacts of a baseball, the variability of rebound caused by loosening of the springs and net after multiple impacts is as unavoidable as it is undesirable because it shortens the useful life of the device.
The goal is to provide an unobviously simple, durable, passive, planar, solid target which is light-weight so as to be portable and stowable; which is not a net yet fulfills the needs of a lone pitcher practicing with a limited supply of baseballs, typically in the range from 1 to 5, so that with a large enough target resting directly on the ground, the time spent chasing pitched balls is limited only to those balls which entirely miss the target. In one embodiment all pitches hitting the target are returned in the general vicinity of the target, mimicking a “bunt”, irrespective of where they strike the target. In another embodiment, the goal is to provide a target which strives to return a pitch striking any portion of its surface at a velocity of at least 100 Km/hr (62 mph), to a zone in the general vicinity of the pitcher, “strikes” being returned closer to the pitcher by virtue of the smaller reflected angle (relative to the horizontal) from the strike zone than a pitch in the upper periphery of the target around the strike zone; alternatively, by choice of the resilience of materials used in the strike zone and in the peripheral zone, a “ball” may be returned closer to the pitcher than a “strike”; and, using each embodiment of the invention, the surface of each returned ball bears no visually noticeable damage due to its impact on the target. It is essential that the entire practice device be an essentially weatherproof, easily portable composite which is stowable in the trunk of an automobile referred to as a “compact”, and weighs in the range from 5-15 Kg (11-33 lb); and despite its light weight militating against maintaining a fixed position when struck with a ball pitched at a velocity in the range from about 100 km/hr (62 mph) to about 160 km/hr (99 mph), the target with a minimum of support structure is to remain stable and immovable in use.
When the resilience of the resilient pad is low as measured by ASTM D1667, pitches are returned as bunts; when the resilience of the pad is relatively higher so as to complement the rebound imparted by a cover sheet tightly tensioned across it, pitches are returned as infield hits. In each case, the pad being backed by a relatively thin, indentable, impact-resistant backstop with defined flexibility, a ball pitched against the resilient pad at a velocity in excess of about 100 km/hr (62 mph) makes a momentary indentation (hence “indentable”) in all three components, the cover sheet, the pad and the backstop. Though such an indentation is minimal relative to the indentation made in a net adapted to return a baseball pitched at the same speed, the combination of physical properties of each structural component and indentation of all three, together with the angulation of the target's surface, is sufficient to bias the return vector (representing the ball) towards the central horizontal axis so as to “serve” the pitch to a chosen location in front of the pitcher. Over a distance of about 18.3 meters (60 feet) the biased return vector delivers the ball closer to the pitcher than the reflected vector.
When the resilient pad is a composite of two pads having markedly different resilience, one central pad dimensioned to correspond to the strike zone and the other pad for the peripheral zone, the pitcher can get a physical confirmation of a strike by choosing the appropriate resilience of each of the pads. The returned distance of a “strike” may be less than or greater than that of a “ball” depending upon whether the choice of the resilience of the central pad, which resilience determines the rebound of the ball, is higher or lower than that of the peripheral pad.
U.S. Pat. No. 3,001,790 to Pratt teaches a simple practice device for a baseball pitcher using a target of wood, plastic, metal or concrete panels, the central panel of the target being vertical and planar, and beveled peripheral panels around the central panel being angulated so that a pitch is returned in a direction dictated by the angle of the panels, only pitches in the central panel being returned along a path towards the pitcher.
The foregoing '790 patent was an improvement upon an earlier relatively complicated practice device disclosed in U.S. Pat. No. 2,162,438 to Letarte, in which plural panels rebound a pitched ball in various directions, the panels imparting different rebounds to balls in accordance with the speed at which each panel is struck, and depending upon which panel is struck. Angulation of a central panel which is covered with resilient material is adjustable so as to present a face at an obtuse angle. Angulation of hinged panels is controlled by an elaborate support structure. The panels may be constructed of wood, metal or other suitable material which will impart a substantial rebound to the ball but there is no enabling disclosure to help choose what physical properties might be critical to provide a particular rebound, namely sufficient to return the ball to a zone in the general vicinity of the pitcher. Recognizing that a concrete surface will provide a baseball pitched against it with substantial rebound, there is no suggestion that the material of choice might itself be resilient enough to be indentable by a baseball striking the material's surface at a velocity of at least 100 km/hr (62 mph). That the material itself is rigid is implicit from the disclosure that the panels are covered with a resilient material to provide the requisite rebound, e.g. a sheet of rubber which is of sufficient thickness to impart rebound to the baseball at a comparatively fast speed when thrown against the target; and again there is no teaching to enable one to find a suitable sheet of rubber, or its thickness, for the specified purpose, or the manner in which it is overlaid on the suitable material, without undue experimentation.
Further, the accuracy of a pitch to the '438 device is determined automatically by the nature of the rebound of the ball, that is, by the angular direction of a returned ball, since the strike zone is fixed by the choice of size of the central panel. Moreover, metal hinges for the panels interfere with the angle of return of the baseball even after their usefulness is impaired by repeatedly being struck by a baseball; and though the stability of the several panels relies upon the size of the large panels which stand at the same height as the batter, the stability is compromised because the lower edges of the panels are not supported on the ground. Much as the '790 patent sought to eliminate the complexities and disadvantages of the '438 invention, and presumably its expected heavy weight, the use of man-made materials not available in nature, in the invention disclosed herein, which materials have the physical properties specified, seeks to improve on the invention disclosed in the '790 patent.
SUMMARY OF THE INVENTION
A passive pitching target, suitable for use by a lone pitcher, comprises a portable and trunk-stowable device including a resilient rectangular laminar backstop indentable by a baseball pitched at a velocity of 100 km/hr (62 mph) (“pitch-indentable”); the target is higher than it is wide, and rests with its base supported on the ground; one planar face of the backstop is fully covered with a soft readily indentable laminar resilient pad of synthetic resinous material having a specified elasticity and resilience, specified to cushion the pitched baseball striking the target's planar surface to return it to a desired location in the range from about 2 m (6.56 ft) to about 15 m (49 ft), and to return it to a location in the range from about 2 meters (6.56 ft) to 5 meters (16.4 ft) from the target, mimicking a “bunt”; the pad is dimensioned for height and width the same as the backstop and is optionally removably or fixedly secured, preferably glued, in contact with the face of the backboard; the thin resilient pad and a portion of the rear surface of the backstop are preferably enveloped in a removably affixed synthetic resinous cover sheet of resilient material tightly stretched and overlying the resilient pad in intimate contact therewith, the three components forming an indentable laminate; a strike zone is visually identified on or through the overlying sheet depending upon whether the sheet is transparent; the strike zone has an area which may be changed to accommodate the need of a pitcher without changing its width; overlapping strike zones for batters of different height are provided for convenience; the area of the target itself is fixed and large enough to return a reasonably errant pitch; and the backstop is braced against the ground, both with its lower edge against the ground, and with a brace wide enough to prevent the light-weight target from being repositioned when the target is struck in either one of its upper comers; the brace includes a pair of interconnected elongate support members (or legs) connected with hinges directly to the rear of the backstop and otherwise unconnected to the backstop; the legs are dimensioned so as to present the planar face of the strike zone at an obtuse angle θ to the ground (which lies in the horizontal plane), the angle being in the range from 100° to about 140°, preferably in the narrow range from 100° to 120° and when folded against the backstop, the legs extend no further than the bottom edge of the target for easy storage in an upright position against a wall; the simple support structure of the support member provides the requisite stability by bracing without any portion of the practice device being staked to the ground.
In a first embodiment, the resilient pad is a unitary rectangular pad of uniform thickness having a single resilience such that a “strike” pitched with a chosen velocity (say 100 km/br, 62 mph) against the strike zone is returned to substantially the same distance from the target as a ball pitched at the same velocity against the periphery of the strike zone, the angle of return, measured in the vertical plane, being essentially the reflected angle relative to the line of flight towards the target, unless modified by the physical properties of the resilient pad and backboard; specifically, a “strike” is returned the same distance from the target as a “ball”, the angle of returns 1 and 2 relative to the normal at the face being different for each, (see FIG. 6 ) if each pitch is released from precisely the same location and in a substantially linear path, each angle being affected by the momentary shape of the curved surface generated by the indentability of the combination of the cover sheet, the resilient pad and the backstop so as to provide an inward bias to the return, toward the central horizontal axis of the target, that is, towards the pitcher. A “strike” delivered to the geometric center of the strike zone in a linear path from a height the same as the center of the strike zone will be returned along a reflected linear path modified by the contribution of the curvature of the surface of the momentary dent; any pitch delivered to any other portion of the target will also be returned depending upon the angle of incidence modified by the effect of the momentary indentation of the target at the location where it is struck. By changing the resilience of the resilient pad and the tension across the face of the resilient cover sheet, the distance to which a pitched ball is returned (the “returned distance”) may be varied. A pad requiring a pressure of 13.8 KPa (2 psi) will return a 100 km/hr (62 mph) pitch less than one half the distance from the location where the pitch was delivered; another pad requiring a pressure in the range from 68.9-344.5 KPa (10-50 psi), will return a 100 km/hr (62 mph) pitch more than one half the distance from the location where the pitch was delivered.
In an analogous manner, the angle of return β, measured in the horizontal plane, is essentially the reflected angle relative to the line of flight towards the target, modified by the physical properties of the resilient pad and backboard, the angle of returns β1 and β2 being different for pitches in the strike zone and in the peripheral area, but also biased towards the central horizontal axis due to the momentary indentation caused by each pitch. Since the target is relatively narrow, the differences in the angle of return in the horizontal plane is of relatively minor concern and are therefore not shown.
The thickness and physical properties of the cover sheet and the extent to which it is tensioned, are critical in their effect on the ball returning capability of the combination of cover sheet, resilient pad and backstop, as well as the angle of return of the ball. However, neither the cover sheet's color, or any pattern on it, are material so long as at least one strike zone is visually defined on the cover sheet's exposed face. The physical properties of the combination of cover sheet, resilient pad and backstop are the same for each portion of the area of the target which functions as if it was a homogeneous laminate, and the strike zone is visually identified only. Since the angle of return of all pitches is biased towards the central horizontal axis of the target due to the momentary indentation of the target by a baseball pitched against it, the difference in accuracies between pitches is determined not so much by the angle at which each is returned but by visual observation of where the target was struck.
In a second embodiment of the target, the resilient pad is a composite of first and second rectangular pads, each having substantially the same thickness but different resilience and colors, the first pad providing the strike zone of desired dimensions, that is, constant width but desired height, and the second pad providing the peripheral target area; and the cover sheet is substantially light transmitting, preferably transparent. A baseball which has an impact in the strike zone (“strike”) is visually seen to have been a strike; confirmation that it is a strike is decreed by the returned distance of the ball, which return distance may be chosen either to mimic a “bunt” or an “infield hit”; for example, a strike may be returned to a distance closer to the pitcher than one striking outside the strike zone, preferably in the range from about 25% to 50% closer to the pitcher than a “ball”, because of the difference in combined resilience and deformations of the structural elements of the target. As before, the momentary indentability of the combination of cover sheet, each resilient pad (whether central or peripheral), and backstop, bias the reflected angle of the returned ball towards the horizontal central axis of the target.
BRIEF DESCRIPTION OF THE DRAWING
The foregoing and additional objects and advantages of the invention will best be understood by reference to the following detailed description, accompanied with schematic illustrations of preferred embodiments of the invention, in which illustrations like reference numerals refer to like elements, and in which:
FIG. 1 is a front perspective view of the practice device, not to scale, resting on the ground.
FIG. 2 is a rear perspective view, not to scale, illustrating the pitching device resting on the ground.
FIG. 3 is a side elevational view, not to scale, illustrating a cross-section of the target and its stabilizing support members.
FIG. 4 is a front elevational view of a composite resilient pad, not to scale, in which the central portion defines a strike zone, and the peripheral portion defines a peripheral target zone, and the faces of the resilient pads are essentially coplanar.
FIG. 5 is a partial vector diagram schematically illustrating the reflected angle of a baseball striking an angulated rigid backstop being substantially the same as the angle of incidence of the baseball.
FIG. 6 is a partial vector diagram schematically illustrating the reflected angle of a baseball striking an angulated resilient and indentable backstop being substantially different from the angle of incidence of the baseball (the indentation is exaggerated in the drawing for illustrative purposes).
FIG. 7 is a front elevational view of a cover sheet, not to scale, on which overlapping strike zones are defined, one for a shorter batter, the other for a taller batter.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The problem referred to above is best addressed by specifying a large enough target with enough mass so as not to require anchoring to the ground yet being readily portable, that is, easily picked up and accommodated in a trunk of a typical “compact”, the weight being no more 15 Kg (33 lbs), preferably in the range from 8-13 Kg (17.6-28.7 lb); further, by providing an inclined target with a combination of a resilient backstop to which a resilient pad is preferably attached with an adhesive, and a cover sheet to function as protection of the resilient pad secured to the backstop with screws driven through the backstop's rear surface. Alternatively, the cover sheet is made of stretchable rubber filled with carbon black, e.g. butyl rubber, and the marginal portions of the sheet are folded over and the corners secured so as to form a tightly stretchable slip-cover which, under tension, can be pulled over the pad and backstop, extending over the edges of the backstop where the periphery of the cover sheet is held in place by the backstop without any fastening means. In this manner, the resilient pad is detachably secured to the face of the backstop, eliminating the need for glue or other fastening means. Thus the cover sheet forms a deformable large planar spring, analogous to a trampoline, cushioned by the resilient pad, a ball pitched against the strike zone is returned within a zone relatively close to the pitcher. This “service” to the pitcher is due to an unexpectedly effective choice of the inclination of the face of the target, the flexural modulus (ASTM D 790) of the backstop, the resilience of the pad, the tensile strength and hardness of the cover sheet, and the use of only a pair of legs for support. The “service” is affected by the physical properties and the manner in which the resilient pad and backstop are overlaid with the thin cover sheet.
When the resilient pad is homogeneous and has a single resilience, the pitcher can visually check whether the pitch has struck a spot within the strike zone which is identified on or through the cover sheet. Though the resilient pad cushions the deformation of both the backstop and the cover sheet, the cover sheet in turn protects the resilient pad from damage due to the full impact of the baseball and from absorbing water if kept outside in the rain.
Referring to FIGS. 1 , 2 and 3 there is schematically illustrated the structure of the practice device identified generally by reference numeral 10 , comprising a generally laminar rectangular target 20 and an adjustable support member 30 pivotably attached near the top, at the rear of the target 20 so that adjustability is restricted to a distance at which the laterally spaced apart feet of the support legs 31 and 31 ′ connected by crossbar 32 , may rest so as to define a stable support area A. The ground-contacting surface of the support structure has an angle Φ of approximately 67° for better stability while in the standing position. The dimensions of the target are such relative to the support member that the lower edge of the target 21 rests on the ground and the face 22 of the target 20 is presented at an obtuse angle θ in the preferred range from about 100° to 120° to the horizontal.
The target 20 comprises a resilient and indentable planar backstop 40 the face of which is fully covered with a resilient pad 50 which in turn is fully covered by a cover sheet 60 , together forming a laminate indentable by a baseball pitched at 100 Km/hr. The thin backstop 40 , less than 0.5 cm (0.2″) thick, has a flexural modulus determined by ASTM D-790 in the range from about 60 to 11,000 MPa (8.7 to 1596.5×10 3 psi). The resilient pad 50 is a unitary rectangular pad of synthetic resinous material having a hardness in the range from about Shore OO 15-95 (ASTM D-2240), having a resilience measured as compressive pressure required to make an indentation 25% of the thickness of the pad, the pressure being in the range from 6.89-344.5 KPa (1-50 psi) and thickness in the range from about 0.2 cm (0.08 in) to about 4 cm (1.57 in), preferably of a homogeneous closed cell or open cell foam of an elastomer.
Referring to FIG. 3 illustrating a cross-sectional view of the target 20 of the practice device 10 , the resilient pad 50 and the indentable laminar backstop 40 each have the same area with a width and length each at least 20% greater than the corresponding dimensions of a chosen maximum area of a strike zone. Preferably the backstop has a length (or height) no more than 1.52 meters (60 inches) and a width of 1.22 meters (48 inches) so as to fit in the trunk of a typical automobile. It is essential that (i) the backstop 40 be constructed from material able to withstand repeated impacts of a baseball traveling at a speed of up to 161 km/hr (100 mph) because of the cumulative damaging effect of such “ball-peening” despite the backstop being protected by the resilient pad 50 and enveloped by cover sheet 60 , wrapped around the edges of the backstop; and (ii) that the weight of the practice device be limited for portability to 15 kg (33 lb), yet be heavy enough to remain stationary when struck by a high-velocity pitch. Upper and lower margins 61 , 62 (side margins are not visible in this view) of the cover sheet are secured to the rear surface of the backstop 40 .
This balance is achieved with a laminar rectangle of impact-resistant glass-fiber reinforced polyethylene having a flexural modulus in the range from about 1448 to 4136 MPa (2.1×10 5 psi to 6×10 5 psi), or less desirably, by a correspondingly dimensioned piece of high density polyethylene (HDPE) sheet about 0.3 cm (0.125″) thick having a flexural modulus of 69 MPa (6×10 5 psi), to which is adhered the resilient pad 50 .
As shown in FIG. 2 , because it is essential that the practice device weigh less than 15 Kg (33 lb) to be easily portable and stowable in an automobile characterized by the term “compact”, only a single pair of support legs 31 , 31 ′ is used. However, they are positioned so as to provide a wide enough base A to counteract a force generated by a pitched baseball striking a corner of the target, or any location within the target. Minimum necessary support is provided when the distance between lines through the two legs 31 , 31 ′ and the bottom of the target is at least one-half the width of the target.
Most preferred to provide the requisite support area is a pair of inextensible elongated rigid struts 31 and 31 ′ interconnected with a crossbar 32 , functioning as twin support members, each pivotably connected to the rear of the backstop, near each side thereof and its upper edge, with hinges 33 , 33 ′. The length of each leg is such that when the legs contact the ground along a line parallel to and laterally spaced apart relative to the lower edge of the backstop, the face of the target is presented at an obtuse angle of 110°; the further away the spaced apart parallel line through the feet of the legs in contact with the ground, the greater the angle θ. The desired angle at which the face is supported is a function of the speed at which the pitcher expects to pitch the baseball, the height of the pitcher, and the distance of the pitcher from the target. No means for locking the legs 31 , 31 ′ in position is normally necessary, the geometry of the support means being such as to make locking the legs unnecessary when the device rests on grass or sand. Locking may be necessary to prevent slippage if the device 10 is placed on a relatively low-friction surface, such as a cemented or other smooth surface. A convenient locking means includes a short strut 35 secured to the rear surface of backstop 40 , the strut having a vertical through-bore 36 in its mid-portion, through which through-bore 36 a cord 34 is passed (see FIG. 2 ); the cord is also passed through a passage 37 in crossbar 32 , and the ends of the cord secured with a locking means 38 so as to restrict movement of the legs 31 , 31 ′ away from the lower edge of the target. Alternatively, a locking strut (not shown) may be used to provide a locking function by securing opposed ends of the locking strut to the strut 35 and crossbar 32 respectively.
Referring more particularly now to FIG. 3 there is illustrated the cover sheet 60 providing the face 22 of the rectangular target 20 ; the resilient pad 50 is covered with the cover sheet 60 of synthetic impact-resistant polymer having a thickness in the range from about 254 μm (micrometers) or 10 mils to 1524 μm (60 mils), in superimposed contact with the resilient pad. The cover sheet is transparent and the thickness of the sheet has no noticeable effect on either the angle or the distance of the rebound of the ball. Underlying the cover sheet is a unitary resilient pad, and the cover sheet overlaps the sides of the backstop for at least 2.5 cm (1 inch).
Reverting to FIG. 1 , the strike zone 70 is outlined on the cover sheet by a first pair of vertical strips 23 , 23 ′ of 2.5 cm (1 inch) wide adhesive tape horizontally spaced apart so that the outer edges of the tapes are at a fixed distance of a standard strike zone, that is, 43.2 cm (17 inches); and a second pair of horizontal strips 24 , 24 ′ vertically spaced apart at a variable distance chosen by the pitcher to correspond with the height of the batter whose strike zone is to be defined. The strips are secured to the exposed outer face 22 of the cover sheet 60 , and the color of the strips is chosen to contrast with that of the cover sheet (see FIG. 3 ).
Referring to FIG. 4 there is illustrated a composite resilient pad 51 comprising a central rectangular pad 52 corresponding in area to a strike zone of choice, and a peripheral pad 53 which snugly envelops the central pad so that the exposed faces of the pads are coplanar; the backstop (not visible, but behind the composite resilient pad) has the same area, as shown in FIGS. 1 and 2 , and both the composite pad 51 and the backstop are covered by a transparent cover sheet (not visible). Either the central pad or the peripheral pad has a resilience greater than that of the other, this difference preferably being in the range from about 15% to 30%, so that a baseball pitched against the surface of one will be returned correspondingly further than a baseball pitched against the surface of the other. Preferably the central pad will have a higher resilience than the peripheral pad to reward the pitcher for accuracy.
Referring to FIG. 5 , there is schematically illustrated the return path of a baseball pitched against the angulated surface of a rigid backstop which is too inflexible to be dented by a baseball pitched against it from point P 1 directly in front of and laterally with respect to point Q in the center of the strike zone. The path of return is along the line to P 2 , the angle of reflection α1 relative to the normal at the point Q being the same as the angle of incidence α1.
Referring to FIG. 6 , there is schematically illustrated the return path of a baseball pitched against the angulated surface of a resilient flexible and indentable backstop which is dented by a baseball pitched against it from point P 1 directly in front of and laterally with respect to the same point Q in the center of the strike zone. The path of return is along the line to P 3 , the angle of reflection α2 relative to the normal at the point Q being less than the angle of incidence α1 because of the contribution of the momentary curvature of the dented surface. The angle α2 being less, the flight of the returned ball is biased towards the path from P 1 which corresponds to the horizontal central axis of the strike zone.
Referring to FIG. 7 , there is illustrated a cover sheet 60 illustrating twin strike zones to avoid repositioning the tapes to practice for batters of different heights. A first strike zone 71 is defined by parallel spaced apart vertical and horizontal striped strips, 25 , 25 ′ and 26 , 26 ′ respectively, to correspond to the strike zone of a batter who is relatively short; and a second strike zone 72 is defined by parallel spaced apart vertical and horizontal dotted strips, 27 , 27 ′ and 28 , 28 ′ respectively, to correspond to the strike zone of a batter who is relatively tall. Though the upper portion of the strike zone 71 and the lower portion of strike zone 72 overlap one another, the strips 26 and 28 ′ defining the overlap, each strike zone is visually clearly defined, differentiating a first strike zone from a second, so as to easily distinguish a strike or a ball for the relevant batter.
In the following illustrative example 1 a practice device is constructed to return a pitched ball as a “bunt”, using the following structural elements:
EXAMPLE 1
A backstop is made from high density polyethylene (HDPE) sheet available from McMaster-Carr Supply Company (“McMaster”), the dimensions of the sheet being 122 cm (48″)×94 cm (37″)×0.32 cm (0.125″). To one face of the sheet is adhered a pad of white melamine foam having a density of 11.2 kg/cu meter (0.7 lb/cu ft) having a resilience measured as requiring 12 KPa (1.74 psi) to provide compression of 25% (also referred to as a 25% deflection). The pad is covered with a sheet of gray vinyl 1 mm (0.040″) thick with the margins of the sheet being uniformly tensioned and secured around the periphery of the HDPE backstop, and a strike zone defined with white adhesive tape.
A support structure illustrated in FIGS. 1-3 is provided by rectilinear or cylindrical struts 29 , 29 ′ which may be of wood such as furring strips, each about 2.5 cm (1″)×3.75 cm (1.5″)×2 cm (0.75″)×69 cm (27″) long, or molded from a polyolefin such as polyethylene. The support structure is hingedly connected to the backstop, each leg with a metal hinge. The support legs are extended so as to support the face of the target at about 120°.
A standard Rawlings Official League baseball pitched from 18.287 meters (60 ft) against the strike zone at 100 km/hr (62 mph) is returned about 6.4 meters (21 feet) from the target; the same baseball pitched against the periphery of the target at the same speed is returned about the same distance from the target.
EXAMPLE 2
In this illustrative example 2, a practice device is constructed with the same structural elements as the device in example 1 above, except that the resilient pad is a composite pad comprising a central pad having dimensions of a chosen strike zone, and a coplanar peripheral pad contiguous with and surrounding the strike pad.
The central pad is cut from 1.25 cm (0.5″) thick black colored Evalite ethylene vinyl acetate foam purchased from McMaster having a density of 32 Kg/cu meter (2 lb/cu ft) and requiring 34.5 KPa (5 psi) for 25% deflection.
The peripheral pad is cut from the same sheet of Melamine used in example 1, to leave a rectangular central aperture into which the central pad is snugly fitted. The dimensions of the peripheral pad are 122 cm (48″)×94 cm (37″).
A “strike” impacting the central pad is returned 84% further from the target than a “ball” pitched against the peripheral pad with the same velocity of 100 km/hr (62 mph).
EXAMPLE 3
The device is constructed in a manner analogous to that described in example 1 except the following resilient materials were used:
Resilient backstop: 0.236 cm×122 cm×94 cm (0.093″×48″×37″) phenolic canvas (H-26000), flexural modulus 138 MPa (20×10 3 psi), obtained from Schoen Insulation Services having Izod Impact Strength 123 N-m/m (2.3 ft-lb/in). Resilient Pad: 0.95 cm (0.375″) thick “Ultimate” rebound polyurethane foam from Leggett & Platt Inc. Coversheet: 0.08 cm thick (0.031″) commercial grade black Neoprene rubber purchased from McMaster-Carr Supply Company. When the face of the target is at an angle of 120 degrees, a standard baseball (Rawlings Official League) pitched from 18.287 meters (60 ft) against the strike zone at 100 km/hr (62 mph) is returned about 3.4 meters (11 feet) from any location in the target.
EXAMPLE 4
Following rubber composition was mixed in a Banbury as described by Sandstrom in U.S. Pat. No. 4,443,279:
Parts Per
Material
Stage
Hundred Rubber
Isobutylene-isoprene rubber
1
70
(Butyl)
EPDM
1
30
N-550 Carbon Black
1
50
Zinc oxide
1
3
Stearic acid
1
1.5
Hydrocarbon resin
1
8
Productive Second Stage
Sulfur
2
2
Mercaptobenzothiazole
2
1.25
Tetramethylthiuram disulfide
2
1
The above compound was calendered into a 117 cm×91 cm×0.04 cm (46″×36″×0.015″) sheet which was formed around a rectangular sheet appropriately dimensioned to yield a slip-cover of the cover sheet with its corners sealed, adapted to be fitted with a chosen tension (across the face of the cover sheet) over a resilient pad provided by a pad of 0.95 cm (0.375″) Poron cellular polyurethane foam from Rogers Corporation, secured to a backstop provided by a glass fiber reinforced (40% by weight) polyethylene sheet 122 cm (48″)×94 cm (37″)×0.16 cm (0.063″) having a flexural modulus of 87×10 6 MPa (12.62×10 3 psi) and Izod impact strength of 213 N-m/m (4 ft.lb/inch) of notch. Since the cover sheet is not fastened to the backstop it is readily removed to change the resilient pad; as before, adhesive tape is used to re-define the strike zone, if necessary.
The support means is provided by a unitary “H-shaped” structure of molded polyolefin struts hingedly connected to the backstop.
When the face of the target is at an angle of 120° a standard baseball pitched from 18.3 meters (60 ft) against any location on the target at 100 km/hr (62 mph) is returned about 7.6 meters (25 ft) from the target.
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A passive pitching target comprises a portable device including a resilient rectangular laminar backstop indentable by a baseball pitched at a velocity of 100 km/hr (62 mph); the target is higher than it is wide, and rests with its base supported on the ground; one planar face of the backstop is fully covered with a laminar resilient pad of synthetic resinous material having a specified resilience to ensure that a pitched baseball striking the target's planar surface is returned to the pitcher at a location of choice, either less than one-half the distance from where the pitch was thrown, to mimic a “bunt”, or, in the general vicinity of the location from where the ball was pitched; the pad is dimensioned for height and width the same as the backstop and is removably affixed in contact with the face of the backboard; the resilient pad, in turn is fully covered with a removably affixed synthetic resinous sheet of material overlying the resilient pad and in intimate contact therewith, the target forming an indentable laminate; a strike zone is visually identified on or through the overlying sheet depending upon whether the sheet is transparent.
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RELATED APPLICATIONS
This application claims the benefit of U.S. Application Ser. No. 61/562,784, entitled “Rapid Prototype Extruded Conductive Pathways”, filed on Nov. 22, 2011, and which is incorporated herein by reference.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
This invention was made with Government support under Contract No. DE-AC09-08SR22470 awarded by the United States Department of Energy. The Government has certain rights in the invention.
FIELD OF THE INVENTION
This invention is directed towards a process of producing electrically conductive pathways within rapid prototyping parts and similar parts made by plastic extrusion nozzles. The process allows for a three-dimensional part having both conductive and non-conductive portions and allows for such parts to be manufactured in a single production step.
BACKGROUND OF THE INVENTION
This invention relates generally to products and substrates having conductive and non-conductive portions. Representative patents on materials having conductive and non-conductive portions include:
U.S. Pat. No. 6,951,233 to Calvar discloses materials having a conductive band within a non-conductive material. The process allows extrusion of conductive and non-conductive materials at the same time but extrudes materials in a straight line and does not offer an ability to extrude complicated conductive shapes and traces.
U.S. Pat. No. 4,858,407 is directed to extruding semi-conductive and non-conductive heat layers on an electrical cable. The extruded layers are essentially cylinders and are concentric. There is no inter-mixing of materials and non-linear products can not be made.
U.S. Pat. No. 5,133,120 provides a method to fill a hole on a circuit board with a conductive paste. The conductive paste joins conductive layers within the circuit board following circuit board production.
U.S. Pat. Nos. 5,925,414 and 6,132,510 are directed to extruding a conductive paste through a stencil or screen onto an essentially planar surface. The method within these patents will not produce a three-dimensional conductive pathway or permit formation of a desired part in, a single step.
U.S. Application 2006/0063060 teaches extrusion of a conductive material such as graphite through a non-conductive substrate to produce conductive pathways through a substrate. The extrusion is a secondary process that requires assembly of the graphite substrate and non-conductive substrate.
There remains room for improvement in variation within the art.
SUMMARY OF THE INVENTION
It is one aspect of one of the present embodiments to provide for a method and process of producing an electrically conductive pathway within a three-dimensional part made by a rapid prototype extrusion machine or a rapid additive manufacturing machine.
It is a further aspect of at least one of the present embodiments of the invention to provide for a process and method extrude a part having conductive and non-conductive material made by selectively extruding conductive materials within desired regions on each layer of the part. The extrusion of the conductive material may be made through the use of a separate extruder head containing a conductive material.
It is a further aspect of at least one of the present embodiments to provide for a three-dimensional substrate having conductive and non-conductive electrical pathways in which the conductive portions are formed through the addition of a conductive material during extrusion, the conductive material including conductive metals such as stainless steel fibers, copper fibers, other metallic fibers, or the use of non-metallic conductive materials such as carbon, carbon nano tubes, carbon nanoparticles and conductive polymers.
It is a further aspect of at least one of the present embodiments of the present invention to provide for an electrically conductive pathway within a three-dimensional extruded part using conductive powder layers applied during extrusion of a part. As used herein, the term “three-dimensional” additionally includes three-dimensional substrates that have a non-uniform shape or geometry with respect to either the final substrate shape and/or to the shape of a respective conductive or non-conductive region or regions within the substrate.
It is a further aspect of at least one of the present embodiments of the present invention to provide for an electrically conductive pathway within a three-dimensional part, which the part is created by a plurality of layers of powders held together with a binder, usually applied in an ink jet manner. When desired, the binder can include a conductive filler, such conductive fillers including nano tubes. The process allows conductive pathways to be printed and/or within the part created by the sequential formation of the respective powder layers and binders, using conductive and non-conductive binder as appropriate to create the conductive pathways.
It is a further aspect of at least one of the present embodiments of the present invention to provide for a process of providing a three-dimensional part having selected areas of electrical conductivity and non-conductivity comprising the steps of:
supplying one of either a rapid prototype extrusion machine or a rapid additive manufacturing machine; and
extruding a three-dimensional part comprising a first portion which is electrically non-conductive and a second portion which is electrically conductive, the second portion including a mixture of a non-conductive substrate with an electrically conductive substrate.
It is a further aspect of at least one of the present embodiments of the present invention to provide for a process of providing a multi-layered object having areas of electrical conductivity and electrical non-conductivity comprising the steps of:
forming a non-conductive substrate by the deposition of multiple substrate layers;
integrating within the multiple substrate layers of the non-conductive substrate at least one three-dimensional region of a conductive substrate, the conductive substrate applied by one of the either stereo lithography, laser sintering, ink-jet printing, or fused deposition;
wherein the multi-layered object has a three-dimensional electrical conductive portion within the non-conductive substrate.
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the present invention are disclosed in the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions.
In accordance with this invention, any number of rapid prototyping apparatuses can be modified as set forth herein to carry out a process for formation of a three-dimensional object having conductive and non-conductive portions therein. U.S. Pat. No. 7,896,639 to Objet Geometries Ltd. describes an apparatus using multiple printing heads for sequentially forming thin layers for a construction material in response to computer controlled data. U.S. Pat. No. 7,896,639 is incorporated herein by reference. Using one or more print heads, as described in the above-referenced application, to dispense a conductive material either in the form of a powder, a binder, or a polymer, a conductive region can be formed in a three-dimensional structure. Suitable conductive powders, binders, or polymers may include carbon nano tubes or fine metallic particles or fibers that are dispensed through the printing heads so as to construct a conductive portion within a three-dimensional part.
U.S. Pat. No. 7,722,802, which is incorporated herein by reference, describes a powder based rapid generative prototyping method. The teachings and methodology described in the '802 patent can be modified as described below in accordance with the present invention.
By controlling the sequential deposition of a conductive powder material, which may include metals, conductive polymers, or a conductive carbon substrate, a three-dimensional body having conductivity there through may be provided. Alternatively, a non-conductive powder may be deposited in and bound together with selectively applied conductive and non-conductive binder. In general, additive manufacturing (AM) represents a technology field that can be used to form three-dimensional objects for solid images. In general, AM techniques build three-dimensional objects, layer by layer, from a building medium using data representing successive cross-sections of the object to be formed. The four primary modes of AM include stereo lithography, laser sintering, ink jet printing of solid images, and fused deposition modeling.
In accordance with the present invention, it is recognized that the present technology directed to using thin layers to form solid structures can be modified such that a portion of the applied thin layers may include conductive materials such as steel wool, copper fibers, other metal fibers, and non-metallic conductive substrates such as carbon based materials including carbon nano tubes or conductive polymers. Suitable conductive polymers which can be applied by one or more of the methodologies described herein include various linear-backbone polymer compounds including polyacetylene, polypyrrole, polyaniline, and their co-polymers and which include various melanins. Included among suitable conductive polymers are poly(fluorine)s, polyphenylenes, polypyrenes, polyazulenes, polynaphthalenes, poly(acetylene)s, poly(p-phenylene vinylene), poly(pyrrole)s, polycarbazoles, polyindoles, polyazepines, polyanilines, poly(thiophene)s, poly(3,4-ethylenedioxythiophene), poly(p-phenylene sulfide), and combinations thereof. Depending upon the nature of the conductive polymer, suitable applicators can be used based upon the material of choice. Various binders including electrically-conductive materials can also be added to the conductive polymers to enhance the use, application, or electrical-conductivity properties.
By applying such conductive materials within a precise location and geometry, a three-dimensional object having an electrical pathway there through can be provided. Using a similar approach, an electrically conductive object may have an appropriate layer of non-conductive material added where needed as an insulator.
The present process allows for rapid production of a part and/or a prototype in which the electrical properties of the part may be evaluated as well as a more traditional mechanical attributes of the part. The present invention lends itself to the production of integrated circuits within a rapid prototype part of the formation of a rapid prototype circuit board. Any three-dimensional part that lends itself to production through AM processes may be modified such that a component of the three-dimensional structure is supplied through an electrically conductive material. As a result, increased functionality of a prototype can be provided. In addition, to the extent the AM is used to manufacture production parts, technology allows an improved way of supplying three-dimensional parts which require defined pathways of conductive and non-conductive regions.
The present process also lends itself to the production of parts that are more difficult to reverse engineer. A traditional electrically wired device can easily be reverse engineered by tracing the wiring configuration. Even for parts that are concealed within a housing which is designed to render inoperative if the housing is removed, reverse engineering can still be accomplished by the use of x-rays or other imaging technology. For some products, the external housing can be melted or dissolved in an effort to preserve the integrity of the sealed interior portion.
The present invention is more resistant to reverse engineering. While x-rays can be used to determine varying density within the extruded layers, it is possible to provide additives to the various insulating and detector materials such that the layers are not readily differentia table using imaging technology such as x-rays. Absent imaging technology, a physical removal of layers is needed which is more difficult and costly. It is possible to match to colors of the various conductive and non-conductive portions such that visual reconstruction of various layers is not readily apparent.
As a result of using conductive and non-conductive materials having similar densities and colors, one can make the reverse engineering process much more complicated. Such capabilities are a useful aspect for certain embodiments of the present invention.
Although preferred embodiments of the invention have been described using specific terms, devices, and methods, such description is for illustrative purposes only. The words used are words of description rather than of limitation. It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or the scope of the claims of the present invention. In addition, it should be understood that aspects of the various embodiments may be interchanged, both in whole, or in part. Therefore, the spirit and scope of the invention should not be limited to the description of the preferred versions contained therein.
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A process of producing electrically conductive pathways within additively manufactured parts and similar parts made by plastic extrusion nozzles. The process allows for a three-dimensional part having both conductive and non-conductive portions and allows for such parts to be manufactured in a single production step.
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BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0001] The invention relates to a method and a device for sensing unbalance-dependent movement phenomena in a laundry drum that is equipped with a rotational sensor as an instrument for measuring the rotational speed.
[0002] Such generic measures are disclosed, for example, in European Patent EP 0 349 798 B1. In accordance therewith, the laundry drum, which rotates in a domestic washing machine about its horizontal axis, is driven through a reduction gear, in this case a transmission, by an electric motor that can be controlled in its rotational speed and is equipped with a tachogenerator as a rotational sensor. Its rotor, functioning as an actuator, resolves in a rotationally rigid manner together with the motor shaft while its stator, functioning as a sensing element, is fixed rigidly to the motor housing which, for its part, is fitted on the tub, within which the drum, which is mounted in the end wall of the tub, rotates. The output voltage or the output frequency of the rotational sensor is a measure of the rotational speed of the motor at a particular instant and thus also for the rotational speed of the drum, which is reduced in relation to the rotational speed of the motor, at a particular instant. The rotational speeds experience unbalance-dependent fluctuations, with the result that the signal fluctuation at the output of the rotational sensor is a measure of the unbalance at a particular instant in the loading of the laundry drum. An unbalance of this type can be encountered in the program sequence of a washing machine or spin-dryer by a laundry distributing phase before the program for driving the drum is switched on to a significantly higher rotational speed for extracting the moisture from the laundry and, finally, for spin-drying the laundry in the drum.
[0003] Such measures have become thoroughly well-established in the case of current washing machines and spin-dryers whose laundry drums have an essentially horizontal axis of rotation. However, rotational sensor systems sense only the rotational speed or the angular acceleration about the axis of the drum, which substantially coincides with the main axis of inertia. On the other hand, in the case of a nonsymmetrical loading with respect to the center point of the axis of rotation of the drum, acceleration components also occur on the drum and result in wobbling movements of the drum in the pitching and yawing direction and in corresponding movement components of the tub, in which the drum is mounted. Such movements cannot be sensed by a sensor whose sensing element is connected rigidly to the tub, since such movements are not orientated centripetally with respect to the axis of rotation about the axis of inertia of the rotation of the drum, but rather are based on unbalance-induced oscillations about the Y-axis and about the Z-axis of a three-dimensional Cartesian coordinate system, if the X-axis thereof is the axis of rotation of the laundry drum. Such unbalance-induced oscillations in addition to those about the X-axis occur, in particular, if the laundry is distributed nonuniformly in the axial direction within the drum. This occurs, for example, in the case of higher cost machines, in which the axis of the laundry drum runs at an inclination to the rear from the engagement opening to make it easier to see in and to make the loading and unloading process much more convenient. As a result, the laundry which, after being lifted up in the drum, drops back in the direction of gravitational force and therefore vertically, is not distributed here to a greater or lesser extent symmetrically with respect to the center point of the axis of the drum. This leads increasingly to unbalance-induced loads about axes of inertia transversely with respect to the axis of rotation, and therefore to the wobbling stresses on the drum and on the tub surrounding it. This results in the risk of the tub striking, in particular laterally, against the inner walls of the appliance housing surrounding it. Although this can be encountered by a greater clear distance between the housing and tub, this brings about, however, a reduction in the drum diameter and thus a reduced loading volume and therefore works against the higher machine price.
[0004] In recognition of these circumstances, the present invention is based on the technical problem of sensing, with the laundry drum loaded, also those unbalance phenomena which result in wobbling stresses on the drum that cannot be detected as a consequence of fluctuations in the rotational speed about the axis of the drum, but which it should also be possible to counteract by control technology so as to avoid critical, unbalance-induced deflections of the tub by the drive of the drum. In particular, the intention of the present invention is therefore to be able to sense unbalance-induced oscillations of the drum that cannot be sensed using a rotational sensor coupled in the conventional manner rigidly to the machine.
SUMMARY OF THE INVENTION
[0005] It is accordingly an object of the invention to provide a method and a device for sensing unbalance-dependent movement phenomena in a laundry drum that overcomes the above-mentioned disadvantages of the prior art devices of this general type.
[0006] With the foregoing and other objects in view there is provided, in accordance with the invention, a method for sensing unbalance-dependent movement phenomena in a laundry drum. The method includes measuring a rotational movement of the laundry drum, and sensing angular accelerations occurring about an axis of inertia transversely with respect to an axis of rotation of the laundry drum, as a fluctuation in a measured value of a rotational speed through a displacement of a sensing element or actuator of a rotational sensor system.
[0007] Accordingly, use is no longer made of a sensing element of the rotational sensor that is coupled rigidly to the appliance, in which the laundry drum rotates, but rather the sensing element can be displaced tangentially (preferably counter to an elastic restoring force and/or against one or two stops) or about the axis of rotation of the actuator, which revolves together with the drum. As a result, the rotational sensor additionally senses an angular acceleration about one of the two other main axes of inertia, which are perpendicular with respect to the axis of rotation of the laundry drum and may therefore result in a wobbling movement of the drum.
[0008] It will normally suffice to derive a measure for the wobbling movement just from the angular acceleration about one of the two axes of inertia which are perpendicular with respect to the axis of rotation of the drum; or in the case of a horizontal axis of rotation, preferably about the vertical axis in order to avoid the wobbling drum striking laterally against the bucking tub surrounding it or to avoid this tub striking laterally against the lateral appliance walls by prompt counter control of the motor in antiphase on the drive side. If, however, in the plane transverse with respect to the axis of rotation of the drum, two rotational sensors having sensing elements which are coupled, according to the invention, elastically to the machine, are disposed orthogonally with respect to each other, continuously updated information about the angular acceleration can be obtained from them for each of the two main axes of inertia transverse with respect to the axis of rotation of the drum.
[0009] This is of particular interest in the case of obliquely mounted laundry drums that are substantially for the user easier to load and unload and offer an easier visual view of the drum contents. The laundry in a rotating, obliquely mounted drum continues, of course, to fall in the direction of action of gravitational force and therefore no longer perpendicularly with respect to the axis of rotation of the drum, in which case an uneven distribution over the axial length of the drum is more probable. This can lead to wobbling movements during the high-speed rotation of the drum, which movements cannot be sensed by conventional rotational sensor systems with their rigid attachment to the appliance. In order to be able to counteract all such possible wobbling movements, for example via an activation of the driving motor of the drum in proper phase, both angular accelerations about the axes of inertia have to be sensed orthogonally with respect to the main axis of inertia X. For this purpose, the output signal of the rotational sensor, which signal indicates the rotational speed of the drum, experiences a variation as a function of the additional pitching or yawing movements of the laundry drum because the particular sensing element of the rotational sensor is, according to the invention, no longer fixed rigidly, but rather can be displaced in the transverse plane to the axis of rotation of the drum counter to the elastic force of a restoring device under the influence of the wobbling forces which occur. Two possibilities according to the invention of displacing rotational-sensor sensing elements, which possibilities are provided orthogonally with respect to each other in this transverse plane, therefore supply separate effects on the results of the continuous measurements of rotational speed on the drum, namely in accordance with the pitching and the yawing stresses on the laundry drum.
[0010] The sensing according to the invention of wobbling movements by measuring the fluctuations which are combined with the current measured value of rotational speed in the case of a displaceable rotational-sensor sensing element can be used not only with an axis of rotation of the drum that is horizontal or that is slightly inclined with respect to the horizontal, but in any desired spatial angular position of the axis of rotation and therefore also in the case of a vertical X-axis or axis of rotation of the drum, as in the case of the “actuator washing machines”. Whereas for the basic explanations above, and also in the description of examples which follows below, the starting point for making comprehension easier is that the actuator of the rotational sensor system is coupled in a rotationally rigid manner to the drum and its sensing element can be pivoted (preferably counter to an elastic restoring force), the reverse assignment can also be realized within the context of the present invention, i.e. a, for example, rotationally elastic coupling of the rotor or similar actuator to the drum with a conventional, rigid coupling of the coil system or similar sensing element to the appliance part which supports the drum. A crucial factor, according to the invention, is that the wobbling stresses on the rotating drum enable the rotational-speed signal supplied by the rotational sensor system to correspondingly intensively fluctuate.
[0011] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0012] Although the invention is illustrated and described herein as embodied in a method and a device for sensing unbalance-dependent movement phenomena in a laundry drum, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0013] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a diagrammatic illustration of a stator of a tachogenerator functioning as a rotational sensor, the stator being coupled elastically to a drum tub according to the invention;
[0015] FIG. 2 is a perspective view of an elastically displaceable light barrier of a pulse-repetition-frequency generator being the rotational sensor; and
[0016] FIG. 3 is a perspective view showing a development of the rotational sensor according to FIG. 2 in order to be able to sense angular accelerations about two axes of inertia, which are perpendicular to an axis of rotation of the drum, and therefore detecting the complete wobbling stress on the laundry drum about the Y and Z-axes.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a rear view being opposite to the loading opening view, of a laundry drum 11 of a domestic washing machine or a domestic spin-dryer, which is mounted rotatably here in a rear wall of a tub 12 (sketched in cubic form). The tub 12 is suspended in an oscillable, but elastically damped manner, in a machine housing 13 . In the simplified illustrations of the drawing, a motor, which is coupled directly or by a gear mechanism to the laundry drum 11 , for the rotational movement of the laundry drum 11 about its axis of rotation 14 that is inclined, for example, with respect to the horizontal has been omitted. However, FIG. 1 does illustrate a transmission 15 for the rotationally rigid coupling of a permanent-magnet-type rotor of a rotational sensor 18 in the form of a tachogenerator 18 to the laundry drum 11 , which is driven by the electric motor. An axis of rotation 20 of the rotor of the rotational sensor 18 is oriented substantially parallel to the axis of rotation 14 of the laundry drum 11 which, for its part, shall be defined in the three-dimensional Cartesian coordinate system (as indicated in FIG. 1 ) as the X-axis. This is the main axis of inertia of the rotating system of the loaded laundry drum 11 in the event of an accumulation of masses that is distributed approximately axially symmetrically with respect to its center point.
[0018] Like the laundry drum 11 , a rotor of the rotational sensor 18 is also mounted rotatably via its stator on the tub 12 . Driven by the drum 11 , the rotor rotates within the coil system of its stator. The rotor therefore functions as an actuator 16 and the coil system functions as a sensing element 17 of the rotational sensor 18 . As a tachogenerator 18 , the rotational sensor 18 supplies an output voltage, which is dependent on rotational speed, or as a frequency generator, the rotational sensor 18 c supplies a pulse sequence, as a function of the rotational speed, to an evaluation circuit which can be provided separately (not taken into consideration in the drawing), but in practice is preferably realized in a microprocessor control of the driving motor for the operation of the laundry drum 11 .
[0019] The particular feature of the rotational sensor 18 lies in the fact that the sensing element 17 in the form of a stator is no longer fixed in a rotationally rigid manner to the tub 12 or other appliance part rotatably holding the drum 11 , but rather can be pivoted about the axis of rotation 20 of the actuator 16 counter to an elastic restoring device 19 , with it being possible for the maximum pivotable deflection to be limited by two non-illustrated stops (one per pivoting direction) as an alternative or in addition to the elastic restoring device 19 . In this case, the sensing element 17 has an eccentric distribution of masses with respect to its axis of rotation 20 , which is illustrated in the sketch by an externally and locally applied, eccentric additional mass 21 . By this measure, in the case of an angular acceleration about the vertical Y-axis as a consequence of a wobbling movement of the drum 11 , a rotational-speed error is combined with the rotational-speed signal of the rotational sensor 18 as a fluctuation in the measured value of the rotational speed, the fluctuation serving, in the evaluation by control technology, as a measure of the current amplitude of the wobbling.
[0020] A drive of the unbalanced laundry drum 11 at a moderate speed of rotation results in a relatively long period of duration for the fluctuating output signals of the rotational sensor 18 , with it being possible for any possible distortions of them as a consequence of slight oscillating movements of the sensing element 17 to be eliminated by measuring techniques, in so far as they cannot be entirely ignored in practice. However, the relative rotational-speed error rises with increasing rotational speed of the drum 11 owing to its tendency to then wobble more severely, and so, at high rotational speeds of the spinning operation, a rotational-speed error which is large enough to evaluate occurs at the output of the rotational sensor 18 owing to the correspondingly severe, wobbling-induced displacement of the sensing element 17 . This fluctuation, which is combined with the measurement of the rotational speed, is therefore in a direct interrelationship with the wobbling movement of the drum 11 as a consequence of angular accelerations about the axes of inertia Y and Z, which are perpendicular with respect to the axis of rotation X, 14 , particularly since, owing to the high potential energy of the loaded drum 11 at high rotational speeds, the rotational-speed fluctuations about the axis of rotation 14 themselves are still very small, even under unbalance effects, in comparison to the fluctuations in measured values caused by the wobbling stresses.
[0021] According to the invention, the pivotably mounted rotational-sensor sensing element 17 thereby senses effects of forces which would not be able to be sensed if the rotational sensor were focused rigidly on the simple rotational movement of the laundry drum 11 , but can nevertheless have a considerable adverse affect on the operational reliability of the machine.
[0022] In the variant according to FIG. 2 , the laundry drum 11 is directly equipped with the actuator 16 of the rotational sensor 18 , with the result that the axis of rotation 14 of the drum and the axis of rotation 20 of the actuator coincide with the main axis of inertia X. A sensing element 17 ′ is secured here rigidly on the tub or housing ( 12 or 13 in FIG. 1 ). The actuator 16 , which rotates together with the laundry drum 11 , has a structure with gaps, for example (as indicated in the enlargement of FIG. 2 ) in the form of slots or apertures of, for example, approximately rectangular cross section which follow one another uniformly in the mark-space ratio of “1”. In this example, the gap-type structure of the actuator 16 is engaged over in a U-shaped manner along its outer edge by a forked light barrier as the sensing element 17 ′. Wherever the actuator 16 is transparent on account of its gap-type structure, the rotational sensor 18 responds because the sensing element 17 ′ connects through. The repetition frequency of the pulses triggered by the light barrier is a measure for the rotational speed at a particular instant of the laundry drum 11 about its axis 14 .
[0023] In addition, the actuator 16 , which is in the form of the gap-type ring which rotates in a rotationally rigid manner together with the laundry drum 11 , is engaged over by the sensing element 17 , which is indeed also fitted to the tub 12 or the housing 13 , but is not secured rigidly, but rather again can be displaced counter to a restoring device 19 in and counter to the direction of movement of the actuator 16 to a structurally predefined degree. Here too, the maximum displacement of the sensing element 17 can be limited by one or two (for the sake of clarity not shown) stops (one per direction of movement of the sensing element 17 ) as an alternative or in addition to the restoring device 19 .
[0024] An eccentric additional mass is not required here because this light-barrier sensing element 17 does not contain any distribution of masses concentric with respect to the X-axis. Its displacement occurs again if, owing to angular accelerations about the axis of inertia Y, forces act transversely with respect to the axis and therefore in the Z-direction to the movably mounted sensing element 17 . In the course of such a displacement of the elastically supported sensing element 17 in or counter to the direction of movement of the actuator 16 , again the pulse repetition triggered by the rotational sensor 18 varies significantly, at high rotational speed of the laundry drum 11 , in relation to the pulse repetition triggered by the sensing element 17 ′ which is fixed on the appliance and senses the rotational movement of the drum 11 about its axis X=14. This variable difference in pulse frequency is a measure for the yawing movement of the laundry drum 11 , i.e. its deflection about the vertical Y-axis in the horizontal Z-direction transversely with respect to the X-direction, the axis of rotation 14 , which is assumed for these exemplary embodiments as being essentially horizontal.
[0025] The development according to FIG. 3 involves, in principle, two rotational sensors 18 , 18 a having displaceable sensing elements 17 of the type as explained above in conjunction with FIG. 2 . These two rotational sensors 18 , 18 a are secured in a manner pivoted orthogonally in relation to each other in a plane which is oriented perpendicularly with respect to the axis of rotation 14 of the drum and therefore lies in the plane of coordinates of the Y and Z-axes. As a result, the one sensing element 17 is displaced again, as previously, owing to angular accelerations, about the Y-axis in the Z-direction, and the sensing element 17 a , which is orientated orthogonally with respect thereto, is displaced, owing to angular accelerations, about the Z-axis in the Y-direction. A comparison of the fluctuating output frequencies of these two rotational sensors 18 , 18 a with respect to the sensing element ( 17 in FIG. 2 ) which is orientated rigidly with respect to the apparatus is now rendered superfluous because the pulse repetition frequencies of the two sensing elements 17 and 17 a , which can be displaced counter to their elastic restoring devices 19 , 19 a , can be compared directly with one another. The relative changes in them are in each case a measure of the wobbling forces, which are now sensed separately in the two coordinate directions transversely with respect to the axis of rotation 14 of the drum.
[0026] The invention thus takes into account that, in particular at higher rotational speeds of the laundry drum 11 , which is driven by an electric motor, not only do angular accelerations about its axis of rotation 14 as the main axis of inertia X occur, but, in addition, pitching and yawing forces which are dependent on the axially eccentric loading occur about the Z- and Y-axes, which are spatially orthogonal in each case with respect to the X-axis, on account of angular accelerations. These result in wobbling movements which cannot be sensed by a rotational sensor 18 , which is coupled rigidly to the machine in a conventional manner parallel to the X-axis, because they are also effective about other axes (Y, Z) than about the X-axis. They lead to a relative movement of the sensing element 17 , which is now mounted displaceably relative to the machine counter to elastic restoring forces, and therefore also relative to the rotational movement of the actuator 16 , with the result that the output signal of the rotational sensor 18 leads to rotational-speed fluctuations which can clearly be sensed by measuring techniques. These are a measure of the current wobbling movement of the laundry drum 11 , which can be actively counteracted by its drive, for example by starting up another rotational speed having smaller resonance-induced deflections of the drum, by changing the gradient of the rotational speed, in order to more rapidly pass through critical resonance frequencies, by redistributing the laundry or, in particular at low spinning speeds, by torque fluctuations of the drum drive combined in proper phase.
[0027] This application claims the priority, under 35 U.S.C. § 119, of German patent application No. 103 45 591.4, filed Sep. 29, 2003, and German patent application No. 10 2004 028 365.6, filed Jun. 11, 2004; the entire disclosure of the prior applications are herewith incorporated by reference.
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The laundry in a rotating, obliquely mounted drum falls in the direction of action of gravitational force and therefore is no longer perpendicularly with respect to the axis of rotation of the drum, which results in an uneven distribution over the axial length of the drum, this leading to wobbling movement during the rotation of the drum that cannot be measured by conventional rotational sensor systems with their rigid attachment. In order to be able to counteract such movements on the drive side, these two further components of inertia have to be sensed orthogonally with respect to the main axis of inertia. For this purpose, the output signal of the rotational sensor, which signal indicates the rotational speed of the drum, experiences a variation in its output signal, the variation being dependent on the additional pitching and yawing movements of the laundry drum.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved process for the purification of crude 1,1-dichloro-1-fluoroethane by treatment with chlorine followed by distillation.
2. Description of the Related Art
1,1-Dichloro-1-fluoroethane (HFA-141b) is a partially halogenated chlorofluorinated hydrocarbon which is proving to be an advantageous substitute for certain entirely halogenated chlorofluorinated hydrocarbons (CFCs) whose production and use are being progressively reduced because they are suspected of having a harmful effect on the ozone layer.
Crude 1,1-dichloro-1-fluoroethane from the synthesis processes is generally contaminated by by-products of the synthesis and undesirable impurities. Certain of these by-products and impurities can be easily separated by distillation. This is especially the case for 1-chloro-1,1-difluoroethane, 1,1,1-trifluoroethane or 1,1,1-trichloroethane, as well as for the heavier compounds comprising a greater number of carbon atoms, formed during the reaction. However, 1,1-dichloro-1-fluoroethane generally contains as impurities small amounts of chlorinated and/or chlorofluorinated unsaturated compounds whose separation by distillation proves to be difficult, in view of their boiling point in the neighborhood of that of 1,1-dichloro-1-fluoroethane.
Besides vinylidene chloride, which is the most important impurity, the unsaturated impurities which may be present in 1,1-dichloro-1-fluoroethane to be purified are mainly cis- and trans-1,2-dichlorofluoroethylenes, trans-1,2-dichloroethylene, dichloroacetylene and 1-chloro-1-fluoroethylene.
Patent Application EP-A-0,401,493 from Atochem North America describes the purification of 1,1-dichloro -1-fluoroethane by photochemical chlorination of the unsaturated impurities followed by a separation by distillation. This process is implemented at a temperature such that 1,1-dichloro-1-fluoroethane is in the liquid phase at the operating pressure. The operating conditions are also in part limited by the presence of the light energy source.
The accent is put in this document on the purification from vinylidene chloride but, in the majority of the examples, it was not possible to fall below 120 ppm by weight of this compound. Additionally, the removal of cis- and trans-1,2-dichlorofluoroethylenes was not mentioned, which are more halogenated impurities whose conversion appears more difficult as, in certain cases, their concentration can increase again after having passed through a minimum. By way of reference, let it be pointed out that the PAFT II specifications (Program for Alternative Fluorocarbon Toxicity testing) impose a total chlorofluorinated unsaturated impurities content not exceeding 10 ppm by weight.
The present invention consequently has the aim of providing an improved process for the purification of crude 1,1-dichloro-1-fluoroethane by treatment with chlorine followed by a distillation which not only makes possible a better purification from vinylidene chloride but also an effective and rapid separation from the other unsaturated impurities, especially cis- and trans-1,2-dichlorofluoroethylenes.
SUMMARY OF THE INVENTION
For this purpose, the invention relates to a process for the purification of crude 1,1-dichloro-1-fluoroethane by treatment with chlorine and then distillation, the treatment with chlorine being carried out in the presence of an organic free radical initiator.
In the process according to the invention, crude 1,1-dichloro-1-fluoroethane is understood to denote 1,1-dichloro-1-fluoroethane and the impurities (including in this the by-products of its manufacture) which it contains.
In order to promote mixing of the crude 1,1-dichloro-1-fluoroethane with the organic initiator, the process according to the invention is preferably carried out in the liquid phase.
The organic free radical initiator has the function of decomposing the chlorine molecules by free radical splitting. According to the invention, the free radical initiator is an organic compound. Among the organic compounds, the peroxide or diazo compounds are most often used. In particular, the peroxide compounds are used. Among these, more particularly the diacyl peroxides, peroxydicarbonates, alkyl peresters, peracetals, ketone peroxides, alkyl hydroperoxides or dialkyl peroxides are chosen. Preferably, the diacyl peroxides or peroxydicarbonates are retained. Excellent results have been obtained with dilauroyl peroxide, dibenzoyl peroxide or dicetyl peroxydicarbonate. The organic initiator is preferably selected from the compounds having a half-life of 0.1 to 3 hours and, most often, of approximately 1 hour at the temperature of the treatment with chlorine.
The organic initiator may be used at very variable doses. It is generally used at a concentration of at least approximately 10 ppm by weight with respect to the crude 1,1-dichloro-1-fluoroethane. In particular, at least approximately 20 ppm by weight of organic initiator are used and more particularly still at least approximately 30 ppm by weight. Most often, not more than approximately 10,000 ppm by weight are used of organic initiator with respect to the crude 1,1-dichloro-1-fluoroethane. Preferably, a figure of approximately 1000 ppm by weight of organic initiator and more preferentially still a figure of approximately 300 ppm by weight is not exceeded.
The treatment with chlorine has the function of chlorinating the unsaturated impurities of the crude 1,1-dichloro-1-fluoroethane. It especially has the function of converting vinylidene chloride, the cis- and trans -1,2-dichlorofluoroethylenes and dichloroacetylene.
The chlorine can be used in the gaseous phase or in the liquid phase. It is introduced, in excess amounts with respect to all the unsaturated impurities to be chlorinated, into the crude 1,1-dichloro-1-fluoroethane.
Generally, the chlorine is used in a ratio of more than 3 mol per mole of unsaturated impurities, preferably at least approximately 4 mol per mole of unsaturated impurities. Most often, it is not desirable to exceed approximately 40 mol of chlorine per mole of unsaturated impurities. It is preferable to limit the amount used in order that virtually all the chlorine can react and is not found as such downstream from the present purification treatment. Preferably, a ratio of approximately 15 mol per mole of unsaturated impurities is not exceeded and more preferentially still this ratio does not exceed approximately 12.
The treatment with chlorine can be carried out in a wide range of temperatures. In particular, the treatment with chlorine is carried out at a temperature of at least approximately 40° C. and more particularly still of more than approximately 60° C. Higher temperatures make possible a faster conversion of the unsaturated compounds, more particularly of the 1,2-dichlorofluoroethylenes, without it being possible for too much formation of heavy compounds to result from parallel substitutive chlorination reactions. However, a correlative increase in the pressure results therefrom which it is advisable to take into account. Preferably, the treatment temperature does not exceed approximately 150° C. and, more preferentially still, it does not exceed approximately 100° C. Excellent results have been obtained when the treatment with chlorine is carried out at approximately from 60° to 100° C.
The treatment with chlorine can be carried out at autogenous pressure or a greater pressure generated by the introduction of an inert gas. In general, the treatment is carried out at a pressure which does not exceed approximately 5 MPa, preferably 2 MPa. Pressures from approximately 0.2 to approximately 1.0 MPa are highly suitable.
These correlated high pressure and temperature conditions allowed for the treatment with chlorine contribute to the efficient and rapid removal of the unsaturated impurities.
The duration of the treatment with chlorine can be from approximately 1 to approximately 120 minutes. Preferably, the duration of the treatment with chlorine is at most approximately 60 minutes.
In the presence of a significant excess of chlorine, the duration of the treatment will be altered in order to limit losses of 1,1-dichloro-1-fluoroethane by substitutive chlorination and formation of 1,1,2-trichloro-1-fluoroethane.
The presence will also be limited of metal ions which could be the origin of the reformation of cis- and trans-1,2-dichlorofluoroethylenes, by dehydrochlorination of the abovementioned 1,1,2-trichloro-1-fluoroethane. This explanation does not, however, bind the Applicant.
The chlorination reactor and the distillation devices are consequently preferably made with corrosion-resistant materials, such as especially the alloys of Monel, Inconel or Hastelloy type.
During the treatment with chlorine, it is seen to that the oxygen content in the chlorine is less than 1000 ppm by volume and preferably that it does not exceed 50 ppm by volume. To do this, the crude 1,1-dichloro-1-fluoroethane is first deaerated by sparging with an inert gas, for example nitrogen.
The distillation which follows the treatment with chlorine has the function of separating the impurities from 1,1-dichloro-1-fluoroethane, after their chlorination. The distillation can be carried out by any known conventional means.
According to an advantageous variant embodiment of the process according to the invention, the organic initiator is introduced into the crude 1,1-dichloro-1-fluoroethane before the chlorine. In a preferred variant of carrying out this embodiment of the invention, the chlorine is introduced into the 1,1-dichloro-1-fluoro -ethane at a temperature in the region of that of the treatment. In a particularly preferred variant of carrying out this embodiment of the invention, the organic initiator is also introduced into the 1,1-dichloro-1-fluoroethane at a temperature in the region of that of the treatment.
The process according to the invention applies to the purification of crude 1,1-dichloro-1-fluoroethane prepared by any synthesis process, without a prior treatment being required. The process according to the invention finds an advantageous application in the purification of 1,1-dichloro-1-fluoroethane obtained by synthesis from vinylidene chloride and hydrogen fluoride. The process according to the invention can especially be used in the presence of compounds whose boiling point is substantially greater than that of 1,1-dichloro-1-fluoro -ethane. Preferably, these compounds are, however, separated beforehand from the 1,1-dichloro-1-fluoroethane. It is also preferable to separate beforehand the compounds whose boiling point is substantially less than that of 1,1-dichloro-1-fluoro -ethane, such as especially 1-chloro-1,1-difluoroethane and 1,1,1-trifluoroethane. These separations can be carried out conventionally by distillation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Examples 1 to 3 illustrate the invention In a non-limiting way. Example 4R is given by way of reference.
EXAMPLES
Example 1
300 ml of crude 1,1-dichloro-1-fluoroethane, containing 110 ppm by weight of dilauroyl peroxide (half-life of 1 h at 80° C.) were introduced, by suction, into a 0.5 1 autoclave made of Hastelloy alloy, equipped with a stirrer, cooled beforehand to 0° C. and put under a vacuum of 1,500 Pa. The solution, maintained at 0° C., was then deaerated by repeatedly passing nitrogen through.
The reaction mixture was then brought to 76° C. by immersing the reactor in a preheated thermostatically controlled bath. The pressure, at this stage, was 4.2.10 5 Pa.
3 g of chlorine, i.e. 5.2 mol of chlorine per mole of unsaturated impurities, were then introduced. The temperature rose to 81° C. and was maintained at this value whereas the autogenous pressure increased to reach 5.2.10 5 Pa after 23 minutes.
Samples were withdrawn during the test, using a sample tube. They were collected directly in a flask containing 50 ml of a saturated aqueous sodium bicarbonate solution, cooled beforehand in ice. After decanting and drying over CaCl 2 , the organic phase collected was analyzed by gas phase chromatography.
Table 1 shows the contents of unsaturated impurities in mg.kg -1 in the crude 1,1-dichloro-1-fluoroethane, before introduction of chlorine and then 23 minutes after introduction of chlorine.
TABLE 1______________________________________ Initial After reaction treatmentUnsaturated compound mixture t = 23 min______________________________________Vinylidene chloride 850 <2Dichloroacetylene 228 <1trans-1,2-Dichloroethylene 920 <1cis-1,2-Dichlorofluoroethylene 79 <1trans-1,2-Dichlorofluoroethylene 43 <21-Chloro-1-fluoroethylene 2 <1______________________________________
These results illustrate that, after only 23 minutes of treatment, there only remains less than 2 ppm by weight of each of the unsaturated impurities present, especially vinylidene chloride and cis- and trans-1,2-dichlorofluoroethylenes. It is thus possible, by distillation, to obtain 1,1-dichloro-1-fluoroethane of high purity.
Example 2
300 ml of crude 1,1-dichloro-1-fluoroethane, containing 71 ppm by weight of dibenzoyl peroxide (half-life of 1 h at 91° C) were introduced into an autoclave identical to that of Example 1 and in the same way. The solution, maintained at 0° C., was then deaerated by repeatedly passing nitrogen through.
The reaction mixture was then brought to 92° C. by immersing the reactor in a preheated thermostatically controlled bath. The pressure, at this stage, was 6.3.10 5 Pa.
4.8 g of chlorine, i.e. 8 mol of chlorine per mole of unsaturated impurities, were then introduced. The temperature rose to 96° C. and was maintained at this value whereas the autogenous pressure increased to reach 7.10 5 Pa after 15 minutes.
Samples were withdrawn during the test and analyzed as in Example 1.
Table 2 shows the contents of chlorinated and chlorofluorinated unsaturated impurities in mg.kg -1 in the crude 1,1-dichloro-1-fluoroethane, before introduction of chlorine and then 15 minutes after introduction of chlorine.
TABLE 2______________________________________ Initial After reaction treatmentUnsaturated compound mixture t = 15 min______________________________________Vinylidene chloride 863 <2Dichloroacetylene 230 <1trans-1,2-Dichloroethylene 937 <1cis-1,2-Dichlorofluoroethylene 80 <1trans-1,2-Dichlorofluoroethylene 42 <11-Chloro-1-fluoroethylene 2 <1______________________________________
Example 3
300 ml of crude 1,1-dichloro-1-fluoroethane, containing 156 ppm by weight of dicetyl peroxydicarbonate (half-life of 1 h at 57° C.) were introduced into an autoclave identical to that of Example 1 and in the same way. The solution, maintained at 0° C., was then deaerated by repeatedly passing nitrogen through.
The reaction mixture was then brought to 57° C. by immersing the reactor in a preheated thermostatically controlled bath. The pressure, at this stage, was 2.9.10 5 Pa.
4.8 g of chlorine, i.e. 11 mol of chlorine per mole of unsaturated impurities, were then introduced. The temperature rose to 63° C. and was maintained at this value whereas the autogenous pressure increased to reach 3.8.10 5 Pa after 22 minutes.
Samples were withdrawn during the test and analyzed as in Example 1.
Table 3 shows the contents of chlorinated and chlorofluorinated unsaturated impurities in mg.kg -1 in the crude 1,1-dichloro-1-fluoroethane, before introduction of chlorine and then 22 minutes after introduction of chlorine.
TABLE 3______________________________________ Initial After reaction treatmentUnsaturated compound mixture t = 22 min______________________________________Vinylidene chloride 879 <1Dichloroacetylene 291 <1trans-1,2-Dichloroethylene 945 3cis-1,2-Dichlorofluoroethylene 84 1trans-1,2-Dichlorofluoroethylene 47 <11-Chloro-1-fluoroethylene 1 <1______________________________________
Example 4R (for reference)
10 g of crude 1,1-dichloro-1-fluoroethane were introduced at room temperature into a 10 ml flask. An amount of gaseous chlorine corresponding to 3 mol of chlorine per mole of unsaturated impurities was then introduced, in a single step, using a syringe, through the Teflon stopper closing the flask.
The sample was then exposed to the radiation from a Philips HP 80 UV lamp in a closed chamber (lamp/sample distance: 15 cm). The temperature was maintained at approximately 35° C. by circulating air in the chamber.
The sample was then analyzed by gas phase chromatography.
Table 4 shows the contents of chlorinated and chlorofluorinated unsaturated impurities in mg.kg -1 in the crude 1,1-dichloro-1-fluoroethane, before introduction of chlorine and then 2.5 h and 8 h after introduction of chlorine.
TABLE 4______________________________________ Initial After treatment reaction t = t =Unsaturated compound mixture 2.5 h 8h______________________________________Vinylidene chloride 295 3 <1Dichloroacetylene 6 <1 <1trans-1,2-Dichloroethylene 189 5 13cis-1,2-Dichlorofluoroethylene 110 5 7trans-1,2-Dichlorofluoroethylene 114 9 101-Chloro-1-fluoroethylene 12 2 3______________________________________
This reference example illustrates that the complete chlorination of vinylidene chloride photochemically demands a very long treatment time and that, even in this case, cis- and trans-1,2-dichloro -fluoroethylenes and 1-chloro-1-fluoroethylene remain present in amounts which are significant with respect to the results obtained with the process according to the present invention.
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Process for the purification of crude 1,1-dichloro -1-fluoroethane by treatment with chlorine in the presence of an organic free radical initiator and then distillation.
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This is a division of co-pending application Ser. No. 350,540 filed on Feb. 19, 1982, now U.S. Pat. No. 4,506,916.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a card made of a thermoplastic material and having visually recognizable safety markings. The invention relates also to a method of manufacturing a card made of a thermoplastic material and having visually recognizable safety markings.
2. Description of the Prior Art
Recently, printed cards made of a plastics material have been widely accepted as credit cards, as money substrate and also as identification cards, which cards can convey a service, a value or an authorization of access. The partial information which identifies the owner of such card as well as the features, which subordinate such card under a certain organization or system is made in form of printings, embossments, punchings or in form of a magnet-, laser- or holographic information on this card. It is thereby relatively simple to copy the outer appearance of such card. It is obvious that accordingly there exists the possibility of a misuse of such cards which replace the longer the more cash transactions, which copying can be made presently without large efforts. Thereby specifically the public has no possibility to ascertain by itself if such card is genuine. Accordingly, cards have been developed and are known which are compound cards having a paper layer enclosed between two plastic layers. The paper layer is provided with a safety printing such as is known in common paper money and comprises such as is the well known case in paper money a watermark which is visible when a person views through the card. Furthermore, parts of the surfaces of the plastic may be provided with a printed pattern. Such cards do provide indeed a higher safety, however have several shortcomings. It has been proven that due to the compound consisting of different materials such as paper and plastic the embossments of the final card will generate a deformation. Due to the tension force exerted on the card it will show an arching or convexity in direction of the embossing, which detrimentally influences the automatic legibility of the above mentioned information in case such information is present thereon. Furthermore, the construction of such known card allows still an illegal intervention thereof. For this reason it is possible to open the card along the paper layer which allows, say, manipulation of this paper layer or it is possible to dissolve the protecting plastic layers by means of a solvent such that thereafter the paper layer is freely accessible. It is now due to above reasons not desired to have such cards made out of a paper-plastic compound. In contrast, it is desired to provide cards made completely out of a plastics material which comprise the necessary safety features. Because, however, such cards preferably have planar surfaces, no design thereof has been known until now which contains adequate safety features such as are, for instance, known to be present in modern bills with paper money which measures presupposed often irregular surface structures. Furthermore, there exist no cards made of a plastics material which have safety features which are visible by viewing through such card, which do not have other significant drawbacks.
SUMMARY OF THE INVENTION
Hence, it is a general object of the present invention to provide an improved construction of a card which comprises visually recognizable safety features without comprising, however, the drawbacks of mentioned known cards.
A further object of the invention is to provide a card made of a thermoplastic material and having visually recognizable safety markings, which card comprises at least two parts placed upon each other, of which at least one consists of a transparent thermoplastic material whereby the inner border area between the two parts comprises a relief-like structure which is given such a shape that upon a suitable viewing at least one safety marking is visually detectable. A further object is to provide a method of manufacturing a card made of a thermoplastics material and having visually recognizable safety markings, having further at least two parts placed upon each other, of which at least one consists of a transparent thermoplastic material whereby the inner border area between said two parts comprises a relief-like structure which is given such a shape that upon a suitable viewing at least one safety marking is visually detectable, which method comprises the steps of embossing by means of an embossing mold a one-sided relief into a first section of a thermoplastic mass; of embossing by means of a correspondingly complementary shaped second embossing mold a one-sided, complementary shaped relief into a second section of a thermoplastic mass; and of joining said two sections having said embossed surfaces nonseparably together.
Two specifically preferred embodiments are under consideration. According to one embodiment the safety marking is preferably viewable when viewing through the card which is arrived at in that one of the two parts consists of an opaque and the other of a transparent thermoplastic material whereby the relief-like structure extends such that in certain areas defining a safety marking the opaque part comprises a locally varying thickness.
The other embodiment is such, that such safety marking is preferably recognizable at the top view of the card, however, at a suitable viewing angle to which end at least one zone or area of the relief-like structure at the inner border area comprises a line-screen raster-like wave shape, whereby such border area is provided with a printed pattern such that the visual appearance thereof changes along with a change of the viewing angle thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully understood by reference to the following detailed description thereof when read in conjunction with the attached drawings, and wherein:
FIG. 1 is a view of a part of a card according to a first embodiment when viewed from above, i.e. when viewed through the card;
FIG. 2a is a schematically enlarged view of a section along line II--II of FIG. 1;
FIG. 2b is a view corresponding to the view of FIG. 2a whereby the two parts are shown prior to their joining together;
FIG. 3 is a view of a schematically enlarged section of a further embodiment of the card shown in FIG. 1;
FIG. 4 is a perspective view at an enlarged scale of a printed part having a wave shaped relief structure;
FIGS. 5a and 5b is a top view each of a card, however viewed at different angles, whereby the card is composed of the parts according to FIG. 4;
FIGS. 6a and 6b are schematic views of sections on an enlarged scale of two further embodiments of the invention; and
FIGS. 7a and 7b is a top view each, shown again on an enlarged scale of a further variant of the embodiments according to FIG. 6, whereby again different viewing angles are embodied.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Although the following description refers to the already mentioned various embodiment of which one refers to a marking when viewing through the card and the other to a marking when simply the card from above are shown separately from each other, it must be mentioned that this separate description of those two procedures is for clarity's sake only and that both embodiments are foreseen to be preferably and advantageously combined such as is schematically shown in FIG. 5.
Firstly, now those embodiments will be described which allow a marking or identification, respectively, when viewing through the card. In FIG. 1 a section of such a card 1 is shown when viewed directly from above whereby presupposed that a light source is arranged behind the card. Thereby two zones are recognizable and defined against the balance of the lighted picture of the card, which two zones may smoothly run into each other. A dark zone 4 and a light zone 5 bordering former zone 4 can be recognized. This corresponds to the well known appearance of a watermark in paper, which watermark is made in that paper fibers are concentrated on certain predetermined locations whereby the areas immediately adjacent to locations of less fibers in that fibers are withdrawn therefrom which leads to the bordering brighter zones. These varying concentrations of fibers lead now to a varying transparency to light, which variation is the reason for the described effect. In a card in accordance with the invention which shall have no paper inserted and which shall be made completely out of a plastics material the mentioned watermark cannot be made according to the above mentioned procedure. To this end a card is made from two half parts or portions, respectively, 2, 3 such as shown in FIGS. 2a and b. One half portion 2 consists of a transparent plastic material and the other half portion 3 consists of an opaque plastic material, i.e. a plastic material which is translucent, can be permeated by light but is, however, turbid. Such material has a higher light absorbing coefficient β, such that light will be substantially weakened when penetrating a relatively thin layer of about 0.4 mm of such material. Now use is made of the fact, that an absorption of light depends on the distance through which the light has traveled, this according to the equation
I=I.sub.o ·e.sup.-βS,
whereby
I o : incoming light intensity
I: Light intensity after passing distance S
β: Light absorbing coefficient.
Accordingly, a larger thickness of the layer leads to a higher absorbing of light. The influence of the transparent half portion 2 is negigible, because its light absorbing coefficient β is extremely small in comparison with such of the opaque layer. The opaque half portion 3 is now shaped such, that in order to shape watermark-like effects zones 4 are shaped which an increased thickness. In the zones 5 immediately adjacent the zones 4 there will be formed zones having a smaller thickness such that when viewing through the card, i.e. specifically through the half portion 3 a brighter zone 5 exists around the darker appearing zones such which is a characterizing feature at common watermarks. In FIG. 2b this is shown schematically by means of arrows which at the one hand represent the incoming light and at the other hand represent the light penetrating the layer whereby the thickness of the arrows represents the light intensity. The embossing of the relief in the opaque half portion 3 proceeds such, that the total amount of the material remains the same and that only a shifting of masses of material out of the zones 5 and into the zones 4 takes place. This leads to the fact, that the mean thickness measured over the zones 4 and 5 having mentioned relief like structure is the same as the thickness of the rest of the card. Such forming is made by means of an embossing tool of known design. The transparent half portion 2 is now provided with a corresponding embossment whereby the embossing tool used hereto is electrolytically formed off the first mentioned embossing tool. Thereafter, the two half portions are bonded together by a laminating to an integral homogeneous part such that they cannot be separated from each other. Along the border area provided with the relief like structure of the two half portions a polymerization of the molecules of the plastic materials takes place such that a molecular binding is formed which obviously cannot be separated. It is obvious, that also a graphical pattern may be printed onto the inner bordering areas in case such is desired. This will be more closely entered into when referring to further embodiments. The surfaces of a card 1 made in accordance with the above description are planar surfaces and may be printed or covered according to known procedures. The characteristic marking of the card is thereby enclosed inside of the card and no access thereto is possible. Thereby, this marking is normally not recognizable at a viewing of the card from the top because the differences of thickness as such are not recognizable at a top view. This makes it now still more difficult to imitate such marking by a corresponding misleading or deceiving, respectively, color print as is sometimes tried with paper having common watermarks in which as is known a small contrast of color is also discernible in a top view thereof.
In FIG. 3 a preferred embodiment of the explained principle is shown schematically in section and on an enlarged scale. In order to shape the relief-like structure of the border area use is made of the screen raster technique. In those zones 4 which shall be darker when viewed through the card the height h 4 of the individual point-like picture of screen elements is chosen to be larger than the height h 6 of the picture screen elements in the main area of the card. In contrast thereto the height h 5 of adjoining zones 5 is kept smaller. Decisive for the light permeability is the thickness of the opaque half portion 3 whereby the mean thickness across the individual zones is measured in case the individual screen points cannot be dissolved or not completely dissolved visually. These mean thicknesses are now chosen such that the effect mentioned already in connection with FIGS. 1 and 2 is visible when viewing through the card. Again the embossing leads only to a shifting of material out of the brighter areas 5 and into the darker areas 4. This shaping of the reliefs in form of a screen raster allows a simple shifting of these material masses and, additionally, increases the border area along which the two half portions of the card are joined together such that an increased adherence of the integral card made of the two half portions is arrived at. The transparent half portion 2 is again complementary shaped.
The relief shaped border area which is made by means of the above explained procedure inside of the card 1 may also be used to identify the card when viewing it simply from the top. If such is coupled with an identification mark which is only recognizable when looking through the card, the one half portion is still to be made of a transparent plastic material and the other from an opaque thermoplastic material.
An embodiment in which this procedure is shown is depicted in FIGS. 4 and 5. In FIG. 4 there is shown a line shaped relief structure arranged at the opaque half portion 3 whereby a corresponding shaping can be seen in its middle section which corresponds to the one shown in FIG. 3. This structure is now printed by a color band 8, which when viewed perpendicularly from above, extends rectilinearly. The opaque half portion 3 manufactured accordingly is mated with a complementary shaped transparent half portion (not particularly shown) to a card of which a section is schematically shown in FIG. 5. In FIG. 5a the appearance of the card is shown when viewed or looked, respectively, through the card. The rectilinearly extending line pattern 8 is recognizable as well as the zones 4 and 5 shaping the watermark. If the card is viewed at an acute angle such as is shown in FIG. 5b, the line pattern appears to be slightly wave shaped and the watermark disappeared. If viewing the card at an acute angle and more exactly, it is possible to recognize this watermark based on the higher amplitude of the waves of the line pattern 8. This combination of viewing through and top view identification increases the difficulty when counterfeiting such cards and accordingly increases their safety.
Finally a further embodiment of the invention is shown in FIG. 6 and 7 which allows an identification in the top view as well as in the through view. In FIGS. 6a and b two variants of this embodiment are shown in section. The border area between the two half portions 2 and 3 comprises each a linearly extending raster screen-like relief structure. Such will be provided on one of the half portions with a printed pattern which in top view changes depending on the viewing angle (FIG. 6a) or which, respectively, leads, when viewing through the card depending on the angle of view, to a changing impression of brightness (FIG. 6b). The first named variant is based on a relief structure which comprises at least roughly a square shape 9. The side flanks as well as the bottoms of the valleys are provided thereby with a color layer 10 whereagainst the crests or peaks, respectively, have no coloring. When viewed perpendicularly from above the colored areas 10 are basically recognizable as lines and when viewed at an acute angle from above, they will complement each other to a continuous colored area. If colors are used with a small translucity for light, one can recognize when viewing through the card depending on the viewing angle various brightnesses. Accordingly when viewing the embodiment of FIG. 6a perpendicularly from above a higher brightness is recognized as when viewing it at a slanted angle. In the embodiment according to FIG. 6b the relief structure as seen in section has a triangular shape 11. One flank 12 is provided with a color layer 12 and the other flank has no color layer. Again, depending on the viewing angle a changing appearance of the printed pattern is visible, which appearance changes from a simple line pattern (arrow at the left hand side of FIG. 6b) to a continuous color area (arrow at the right hand side of FIG. 6b). When viewing through the card the recognizable brightness is asymmetrical in case a color is used having a small light permeability. If the card is turned to the side beginning from a perpendicular orientation thereof, the brightness increases, and if the card is turned to the other side, the brightness decreases.
The mentioned embodiments can obviously be made further such that in addition a watermark appears when viewing through such card, such as mentioned above based on FIGS. 1 to 4. Furthermore, it is possible to add further safety features such as shown, for instance, in FIGS. 7a and b. This embodiment of the arrangement in accordance with FIG. 6a comprises a corresponding printing pattern which, however, is provided with gaps 13, which are arranged in line in certain directions. In the top view (FIG. 7b) this is not recognizable because this structure is an extremely fine structure. If, however, viewed at an extremely flat angle (FIG. 7a) bright alleys are clearly visible in a dark background. This effect is basically known from paper money, from bills whereby however an unplanar surface is presupposed and such can be used such as explained above without any further ado as an additional safety feature in planar plastic cards.
It is quite obvious that the planar surfaces of such plastic cards can be printed in a known way. In order to use the above mentioned features which must be viewed from the top, at a certain angle etc. the corresponding areas on the card must be provided with windows. Furthermore, parts of the information of the card itself may also be located at the printed pattern in the border area.
The described arrangement having a relief-like shape border area which may additionally be provided with a printed pattern and which extends between two card portions which are connected such that they can no longer be separated allows, as described above, many advantageous possibilities of a visual security measure of such cards which until now has not been achieved or possible. Thereby absolutely planar surfaces are maintained. Embossments in the card do not lead to an arching or convexing thereof such as is known by known compound cards. An access to the safety features for counterfeiting purposes is not possible.
A specifically advantageous use of a marking which can be recognized when viewing through the card by utilization of a relief shaped structure at the bordering area between the opaque portion 3 and the transparent portion 2 according to FIGS. 1 to 3 is to shape the relief structure in accordance with the portrait, a photographic picture of the card owner. When viewing through the card this portrait, photo of the owner appears in a watermark-like form and can be compared at any time with a real photograph of the owner or obviously with the owner himself. Accordingly, it is possible to have a further and individual recognition feature. This is specifically possible due to the fact, that the relief-like structure of the bordering area can have areas of varying thickness which flow smoothly into each other, which--contrary to the common watermarks, which usually are provided with just two brightness steps--provide when viewing through the card a picture with smooth variations of brightness between a maximum and a minimum.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims.
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In order to form safety markings at a planar card made of a plastics material, which card may be used, for instance, as credit card, this card is built up from at least two parts. The inner border area between these two parts comprises a relief-like structure which is the carrier of the safety marking. In order to generate a watermark-like effect the upper part is made of a opaque plastic material and the other part is made of a transparent plastics material. When viewing through this card the areas of the opaque layer having the largest thickness appear as darker areas, whereby when viewing the same way the areas having a smaller thickness show a certain brightness. After being embossed the two parts of the thermoplastic material are joined to each other such that they cannot be separated such that no access from the outside is possible to this safety marking. Accordingly, an additional safety factor is arrived at in cards which can be used as money substrate, identification means or a license for any kind of access.
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Velvet has long been considered one of the most opulent of fabrics. It has been found in the robes, crowns and thrones of monarchs. In the past, the beauty and luxurious touch of velvet was obtained by incorporating silk into the pile of the fabric. This necessarily kept velvet from the less than well to do. Sculpturing enhances the beauty of velvets but adds further to the cost. While purists would insist that any true velvet must contain silk, synthetic velvets have recently appeared which rival the true velvets in luxury and touch at substantially lower cost. Methods of producing the ornate look of sculptured velvets at moderate costs have recently been developed. A method of sculpturing pile fabrics has been disclosed in allowed U.S. Patent Application Ser. No. 750,618, now U.S. Pat. No. 4,112,560. An apparatus for carrying out this process has been disclosed in U.S. Pat. No. 4,085,700. These applications describe a method of trimming the pile from selected regions of a pile fabric by applying a stiffening agent to the regions of the pile from which the pile is to be removed, hardening the stiffening agent and drawing the fabric past a blade which contacts the pile in both the stiffened and unstiffened regions. The unstiffened fibers deflect away from the blade without being cut, but the stiffened fibers cannot deflect away and are severed. The apparatus described in these applications is capable of sculpturing fabrics of truly moderate cost but it is relatively sensitive to defects in the fabrics being processed and requires precise adjustment to achieve commercially acceptable sculpturing. Further, this apparatus has proved rather unforgiving of small deviations from precise alignment, which sometimes caused the blade to damage the unstiffened fibers, sculpture unevenly or cut through the substrate.
Recently, improvements have been made in this apparatus which make it much more forgiving of deviations from ideal alignment. In particular, it has been found that it is very advantageous to use a blade having an asymmetric shape for sculpturing. When a translating blade is used for sculpturing, it has proved advantageous to support the fabric either on a rotating knurled nose bar adjacent to the blade or on a rotating nose bar having a smooth center portion and a recessed portion coinciding with the selvage of the fabric to be sculptured. The recessed portion has threads cut into it which grip the selvage of the fabric and counteract the drag of the blade on the fabric.
When patterns having straight lines which coincide with either the warp or the weft of the fabric are to be sculptured, it was found that the lines were often of uneven thickness and that it was difficult to sculpture patterns with equal line width in either the warp or weft directions. These difficulties can be minimized if the screen used for printing has apertures arranged on a uniform hexagonal lattice of equilateral triangles wherein the angle between the base of each equilateral triangle and circumferential lines on the screen is substantially 15°.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevation illustrating a fabric sculpturing device of the present invention.
FIG. 2 is a view taken along line 2--2 in FIG. 1.
FIG. 3 is a sectional view taken along line 3--3 in FIG. 2.
FIG. 4 illustrates an alternative construction of the roller supports shown in FIG. 3.
FIG. 5 is an enlarged sectional view taken along line 5--5 of FIG. 4.
FIG. 6 is a side elevation view of an alternate nose bar for use in the sculpturing device.
FIG. 7 is an enlarged fragmentary view of FIG. 1 showing the cutting zone in more detail.
FIG. 8 is still a further enlarged fragmentary view of FIG. 1 illustrating the geometry of the blade.
FIG. 9 is a schematic view illustrating the pattern of the background design used in forming screens for use in the present invention.
FIG. 10 is a view illustrating the array of apertures formed when axes of symmetry of the background design are parallel to the lines in the pattern.
FIG. 11 is a view illustrating the array of apertures properly used for printing patterns having lines which are parallel to the warp or weft directions.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For a complete understanding of the present invention, it is advantageous to refer to the teachings of allowed U.S. Patent Application Ser. No. 750,618 and U.S. Pat. No. 4,085,700 both of which are hereby incorporated by reference.
In FIG. 1, pile fabric 10 which has been printed with stiffening agent in accordance with the teachings of the above-mentioned applications is stored in scray 12. To insure that pile fabric 10 is unwrinkled and evenly tensioned as it passes over nose bar 14 adjacent to blade 16, it is first passed over rollers 18, driven rollers 20 and then over spreader 21, roller 22, and spreader 23. Pile fabric 10 passes over nose bar 14 and is taken up by driven spreaders 24, driven rollers 26 and is stored on take up roll 28. Since it is important that pile fabric 10 be uniformly tensioned as it passes over nose bar 14 and to avoid start up problems, band knife 30 having translating blade 16 is mounted on pivotable carriage 32, while the fabric handling system is rigidly mounted on frame 34. This makes it possible to always maintain pile fabric 10 in a tensioned state even when blade 16 is retracted to allow seams to pass.
Since blade 16 is a translating endless band, it is advantageous for it to have a slight amount of curvature so that it can easily be maintained in one position. The abovementioned applications teach the desirability of matching the curvature of nose bar 14 to the curvature of blade 16. FIGS. 2 and 3, illustrate an especially advantageous mechanism for supporting nose bar 14 and maintaining uniform spacing between nose bar 14 and blade 16. Nose bar 14 rests upon rollers 36. Four rollers 36 are mounted on each pillow block 38. Pillow block 38 can be extended or withdrawn by adjusting positioning screw 44. By properly adjusting set screws 40, 41, 42, 46, 48, 50, 52, and 53, it is possible to orient pillow block 38 and thereby rollers 36 mounted on pillow block 38 so that the center lines of each set of rollers 36 are substantially parallel to the portion of blade 16 nearest that set of rollers 36. For example, in FIG. 2 on any pillow block 38 by turning set screws 52 and 40 counterclockwise as viewed from their respective heads while similarly turning each set screw 53 and 41 clockwise, it is possible to tilt pillow block 38 such that the right hand pair of rollers 36 is lifted slightly above the plane of the page while the left hand pair of rollers 36 is depressed slightly below the page. Similarly by turning set screw 48 counterclockwise as viewed from its head while similarly turning set screw 46 clockwise, it is possible to rotate each set of rollers 36 slightly clockwise as viewed in FIG. 2. By turning screws 40, 41, and 50 counterclockwise as viewed from their heads while similarly turning screws 42, 52, and 53 clockwise it is possible to lower the entire pillow block into the page as seen in FIG. 2. It is also possible to raise the portion of pillow block 38 nearest nose bar 14 out of the page while lowering the portion nearest set screw 44 into the page by turning set screws 40, 41, 52, and 53 counterclockwise while turning set screws 42 and 50 clockwise. This method of supporting and positioning rollers 36 makes it possible to match the curvature of nose bar 14 to the curvature of blade 16 closely.
FIGS. 4 and 5 illustrate an alternative construction for the roller supports wherein two long rollers 37 are rotatably mounted on each pillow block 39 which can be adjusted in the same fashion as pillow block 38. Whichever construction is used, it is very advantageous that the rollers be capable of exerting a bending force or moment upon the nose bar 14 when fabric 10 is tensioned. This requirement is met in the construction shown in FIGS. 2 and 3 since the rollers 36 rotatably mounted on each pillow block 38 are spaced apart by a distance which is more than three times the diameter of the nose bar 14. In FIGS. 4 and 5, the requirement is met since the length of rollers 37 on each pillow block 39 is greater than three times the diameter of nose bar 14.
In FIG. 2, nose bar 14, supported on rollers 36, has a substantially cylindrical center portion 56, a recessed end portion 58 with right hand threads 60. Recessed end portion 62 is formed in nose bar 14 at the end opposite the end in which recessed portion 58 is formed. In operation, blade 16 (not shown in FIG. 2) moves from right to left and exerts a drag on pile fabric 10 acting toward the left. Threads 60 in recessed portion 58 grip the right hand selvage of pile fabric 10 and pull it toward the right thus countering the drag of blade 16 on pile fabric 10 and reducing the tendency for pile fabric 10 to wrinkle on nose bar 14 due to the drag of blade 16. The left hand selvage is accommodated by recessed portion 62.
FIG. 6 illustrates alternative nose bar 114 which may be used in place of nose bar 14. Nose bar 114 is assembled from substantially cylindrical core 64 having internally threaded ends, smooth surfaced hollow cylindrical thick rings 66, knurled hollow cylindrical thick rings 68 and internally threaded smooth end portions 72. The nose bar is assembled by threading one end portion 72 into core 64, sliding a plurality of alternate smooth thick rings 66 and knurled thick rings 68 cover core 64, and threading end portion 72 into core 64. Smooth thick rings 66 coincide with rollers 36 and are hardened so they are not damaged by pressing against rollers 36 while knurled thick rings 68 grip fabric 10 and counteract the drag of blade 16. Ideally, the outer diameter of the projections or knurled rings 68 will be about 0.005 inches greater than the outer diameter of smooth rings 66 to prevent fabric 10 from slipping on nose bar 114. Recesses 70 formed in end portions 72 accommodate the selvages of fabric 10. This method of construction is very advantageous since it allows smooth thick rings 66 to be hardened after they are formed. It would be difficult to heat treat an entire bar after it was machined without warping it.
As shown in FIG. 7, blade 16 is confined between retainer plates 74, mounted on blade supports 76 which are mounted between support beams 78 on pivotable carriage 32.
As shown in FIG. 8, blade 16 has narrow facet 80 adjacent to face 82 which is adjacent to fabric 10 (omitted for clarity). Tip 84 of blade 16 is defined by the intersection of narrow facet 80 and wide facet 86. In preferred embodiments, the angle, B, between the normal to fabric 10 and narrow facet 80 will be between about 30° and about 60° while the included angle, A, between narrow facet 80 and wide facet 86 will be from about 75° to about 105°. The width, W, of narrow facet 80 will be less than about 1/3 the depth of the pile on the fabric to be sculptured. In more preferred embodiments, the angle, B, between narrow facet 80 and the normal to fabric 10 is about 48° plus or minus about 5°, the included angle, A, of blade 16 is about 85° plus or minus about 5° and the width, W, of narrow facet 80 is less than about 1/10 the depth of the pile of fabric 10. In still more preferred embodiments for sculpturing of pile upholstery fabrics, the width, W, of narrow facet 80 is between about 0.003 inches and 0.010 inches. In the most preferred embodiment for sculpturing of acrylic pile upholstery fabrics, the width, W, of narrow facet 80 is about 0.008 inches plus or minus about 0.001 inches while the most preferred width, W, for sculpturing of polyester pile fabrics is about 0.006 inches plus or minus about 0.001 inches. It is found that when blade 16 has the geometry described above, damage to the unstiffened pile is minimized and sculpturing is relatively forgiving of both defects in the fabric and minor variations from optimum alignment of nose bar 14 with respect to blade 16.
When designs having straight lines parallel to either the warp or the weft of the fabric are printed using conventional screens, it is found that often the lines are of non-uniform width. It has been found that this problem is caused by non-uniform line patterns which result when the lines in the pattern are parallel to an axis of symmetry of the design from which the screen is made. Screens for printing are often made by coating a slightly tapered mandrel with known photo-sensitive materials. The portions of the mandrel which correspond to areas which are to be open in the screen are exposed to light while the remainder is masked so that it remains unexposed. Upon subsequent treatment and electroplating by known methods, a thin removable screen is formed having openings in the areas which were exposed to light.
The mandrel is normally masked by wrapping a negative around it. The negatives are usually sequentially exposed to a background pattern and a design pattern. A typical background pattern is shown in FIG. 9. FIG. 10 illustrates a typical pattern resulting when the lines in the design pattern are parallel to an axis of symmetry of the background pattern. Vertical line 90 is composed of a series of fully open hexagons 92 while vertical line 94 is composed of two series of partial hexagons 96 and 98. Similarly, it can be seen that horizontal line 100 is composed of an alternating series of one full hexagon 102 followed by two half hexagons 104 while horizontal line 106 is composed of a series of partial hexagons 108 and 110. If a screen such as is depicted in FIG. 10 is used for applying adhesive, the amount of adhesive applied through the openings 92 in vertical line 90 will be greater than the amount applied through the openings 96 and 98 in vertical line 94. There are two principal reasons for this effect. First, when the mandrel is plated, the smaller holes 96 and 98 in lines 94 will tend to close up more than the holes 92 in line 90. Thus, the actual total open area formed by the holes 96 and 98 in line 94 will be less than the open area of the holes 92 in line 90. Indeed, holes 98 may close up entirely. Second, even if the percentage open area of the two were the same, more adhesive would flow through the holes in line 90 since more adhesive will flow through a large hole than through two small holes even if the total area of the two small holes combined is equal to the area of the large hole. Similarly, it can be seen that more adhesive will be deposited through vertical line 90 than through horizontal lines 100 or 106. It is difficult to say whether more adhesive would be deposited through horizontal line 100 or horizontal line 106, but it is certain that in many cases the amounts deposited will differ. These effects are undesirable since uneven sculpturing usually results when more adhesive is applied to one line than another. This effect is especially noticeable when regular patterns such as checkerboards or evenly spaced stripes are sculptured.
It has been found that these effects are minimized if no axis of symmetry of the background pattern is parallel to lines in the design pattern. If the background pattern has spaced apart apertures located on the vertices of an array of uniform equilateral triangles, this requirement is met by positioning the background pattern such that there will be a 15° angle between the axis of symmetry of the background pattern and circumferential lines on the screen. FIG. 11 illustrates a screen for printing lines in both the warp and weft directions using the present invention. On the screen shown in FIG. 11, the apertures define longitudinal or weft lines 116 and 118 and circumferential or warp lines 120 and 122. It can be seen that the geometric centers of adjacent apertures are located on the vertices of an array of equilateral triangles. The term "geometric center" of an aperture is to be understood to indicate the point where the center of that aperture would be if that aperture were complete whether or not the actual aperture is complete. For example in line 116, the geometric center of partial hexagon 124 would be located at point 126 and the geometric center of partial hexagon 128 would be at point 130. Thus, in FIG. 11, it can be seen that apertures 124, 132, and 134 define an equilateral triangle having sides 136, 138 and 140. The angle between side 136 and the circumferential direction is substantially 15°. The angle between side 138 and the longitudinal direction is substantially 15°. The angle between side 140 and either the longitudinal or circumferential direction is substantially 45°. All of the apertures shown in FIG. 11 are located such that their geometric centers define an array of equilateral triangles each having one side which defines a 15° angle with respect to the circumferential direction, another which defines a 15° angle with respect to the longitudinal direction and a third which defines a 45° angle with respect to both the circumferential and longitudinal directions.
It is not necessary that the apertures be hexagons as long as their geometric centers are located at the vertices of a uniform array of equilateral triangles satisfying the condition set out above. In the case of apertures having generalized shapes, the geometric center of any aperture is located at the point where the center of area of that aperture would be if it were complete whether the aperture is complete or incomplete. For example, the geometric center of a partial circle would be at the center of curvature of the arc of the partial circle.
If the conditions set forth above are satisfied, lines in the warp and weft directions will be printed properly so that lines which should be of uniform width will be uniform.
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An improved sculpturing apparatus having an asymmetric blade, improved fabric support means and an improved screen for applying stiffening agent is disclosed.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C. §120 to U.S. provisional application No. 62/272,997, filed Dec. 30, 2015, the disclosure of which is incorporated by reference herein in its entirety.
1. TECHNICAL FIELD
[0002] The present invention relates to in-car entertainment or in-vehicle infotainment.
2. DISCUSSION OF RELATED ART
[0003] In-car entertainment (ICE), or in-vehicle infotainment (IVI), is a collection of hardware and software in automobiles that provides audio or video entertainment. In car entertainment originated with car audio systems that consisted of radios and cassette or compact disc (CD) players, and now includes automotive navigation systems, video players, universal serial bus (USB) and Bluetooth connectivity, Carputers, in-car internet, and WiFi. Once controlled by simple dashboards, knobs and dials, ICE systems can include steering wheel audio controls and handsfree voice control.
SUMMARY OF THE INVENTION
[0004] According to an exemplary embodiment of the present invention, there is provided a rear seat entertainment system including: a first access point, wherein the first access point includes a first display screen and a plurality of input/output ports, and wherein the first access point is included in a first housing; and a second housing separate from the first housing, wherein the second housing includes a second display screen, wherein the first access point is configured to display first content on the first display screen and stream the first content displayed on the first display screen to the second housing so that the first content is simultaneously displayed on the first and second display screens, and wherein the first access point is further configured to receive second content from a first mobile device, display the second content on the first display screen and stream the second content displayed on the first display screen to the second housing so that the second content is simultaneously displayed on the first and second display screens.
[0005] The first and second housings are each configured to be disposed inside a vehicle seat headrest.
[0006] The first and second housings are each configured to be mounted to a vehicle seat.
[0007] The plurality of input/output ports include a high-definition multimedia interface (HDMI) port, a universal serial bus (USB) port, an analog audio output port and a secure digital (SD) card port.
[0008] The first access point further includes a digital video disc (DVD) player.
[0009] The rear seat entertainment system further includes an infrared remote control.
[0010] The first access point is further configured to stream the first content displayed on the first display screen to the first mobile device so that the first content is simultaneously displayed on the first display screen, and a third display screen of the first mobile device.
[0011] The first access point is further configured to stream the first content displayed on the first display screen to a second mobile device so that the first content is simultaneously displayed on the first display screen, the third display screen of the first mobile device, and a fourth display screen of the second mobile device.
[0012] The first mobile device is a smartphone or a tablet.
[0013] The second housing includes a second access point, wherein the second access point is configured to steam third content to a second mobile device so that the third content is displayed on a third display screen of the second mobile device.
[0014] According to an exemplary embodiment of the present invention, there is provided a vehicle entertainment system including: a master device, the master device including a first display screen and a plurality of input/output ports; and a first satellite device, the first satellite device including a second display screen, wherein the master device is configured to receive a hardwired connection via one of the plurality of input/output ports from a first portable device, receive first video content from the first portable device through the hardwired connection, display the first video content on the first display screen and wirelessly steam the first video content to the second display screen, and wherein the master device is further configured to stream the first video content to a second mobile device.
[0015] The master device and the satellite device are each configured to be disposed inside a vehicle seat headrest.
[0016] The master device and the first satellite device are each configured to be mounted to a vehicle seat.
[0017] The master device is further configured to receive second video content via a WiFi connection and wirelessly stream the second video content to the first mobile device or the second mobile device.
[0018] Content streaming operations of the master device are controllable with the first or second mobile devices.
[0019] The master device is configured to establish a dedicated in-car wireless network.
[0020] At least one of the first mobile device and the second mobile device is a smartphone or a tablet.
[0021] The master device further includes a plurality of input/output ports, wherein the plurality of input/output ports include an HDMI port, a USB port, an analog audio output port and an SD card port.
[0022] The master device further includes a DVD player.
[0023] The vehicle entertainment system further includes a second satellite device configured to play video content independent of video content played on the first satellite device or the master device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 illustrates a master device according to an exemplary embodiment of the present invention;
[0025] FIG. 2 illustrates a system including the master device, a satellite device and mobile devices according to an exemplary embodiment of the present invention;
[0026] FIG. 3 illustrates a wiring diagram of a system according to an exemplary embodiment of the present invention;
[0027] FIG. 4 is a circuit diagram of a satellite device according to an exemplary embodiment of the present invention; and
[0028] FIGS. 5A and 5B show a circuit diagram of a master device according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0029] Disclosed herein is an interchangeable rear seat infotainment system according to an exemplary embodiment of the present invention.
[0030] In the infotainment system according to an exemplary embodiment of the present invention, users can create and securely log into their own wireless in-car rear-seat infotainment networks and share and stream media content across all occupants of the vehicle regardless of whether the content is stored and viewed on the EVO system or stored and viewed on a passenger's mobile device. The infotainment system accepts content from secure digital (SD) card and high-definition multimedia interface (HDMI)/universal serial bus (USB)-based devices, supports Miracast and digital living network alliance (DLNA) functionality, and features the ability to provide consumers with a live TV experience. For example, using the infotainment system, Slingbox users can connect through an in-car Wi-Fi hotspot and watch the same cable/satellite television package they have in their home including on-demand and previously recorded digital video recorder (DVR) content.
[0031] Some exemplary features of the infotainment system include: large (8″, 10.1″ and up), high resolution screens designed for Headrest, Seatback, Center Console and Overhead installations; digital Bluetooth connection to the vehicle's infotainment system for high-quality audio playback; traditional “D-Pad” mini remote and mobile smart device app control system facilitating control from a smartphone or directly from the vehicle's center stack; enhanced, intuitive user interface; portable device charging; smart device connectivity and content sharing; simplified vehicle integration with the ability to add the infotainment system to a vehicle independent of its existing controller area network (CAN); flexible architecture designed for feature expansion and updating to meet the changing mobile environment; distributed content playback which allows all screens and smart devices to view the same movie simultaneously.
[0032] The system architecture comprises two monitor types, Master and Satellite. FIG. 1 shows a Master, while FIG. 2 shows a Master and a Satellite. For example, FIG. 1 shows a Master that includes a display, a DVD player, an SD card port, an audio output port, a USB port, an HDMI port and capacitive touch buttons for control of a graphical user interface.
[0033] The individual monitor types of the infotainment are as follows: EVO 0—Display only (Satellite), EVO 4, (Master with no DVD) and EVO 5, (Master with DVD), for example. The system's wireless components integrate as EVO 5 & EVO 0, EVO 4 & EVO 0, or two EVO 5 monitors. The Master monitor (EVO 4 & EVO 5) are standalone. The EVO 0 (Satellite) must be used in conjunction with either EVO 4 or EVO 5. In other words, EVO 0 is an auxiliary component.
[0034] Each infotainment system may contain the following at a minimum: integrated Power Filter; a combination of any two system individual monitor types; a method to share audio/video between components; infrared (IR) Remote Control; IR Wireless Headphones, one for each monitor; and text to speech capability.
[0035] Each component may have its own feature set. In this disclosure, the term “component” may mean one of EVO 0, 4 and/or 5. Each system component has the ability to have their microcontroller (MCU) Firmware Profile flashed and software updated via a user accessible USB. Each component may have its own designation which will have its own fit form or function defined.
[0036] The following tables contain each system component designation and its feature matrix.
[0000]
TABLE 1
EVO0 Feature Matrix
EVO0 Feature Matrix
Feature
Description
Display Panel
1024x600 WSVGA High Resolution Display
Panel
Audio
Wired Headphones
3.5 mm jack wired headphone output
IR Headphone Output
Analog IR headphones
System Control
IR Remote Control
IR remote control of system
GMSL Connection
Used for system component interconnect
Low-Level micro-
Basic microcontrollers needed for functions
controller system
[0000]
TABLE 2
EVO4 Feature Matrix
EVO4 Feature Matrix
Feature
Description
Display Panel
1024x600 WSVGA High Resolution
Display Panel
Connectivity
USB 2.0
USB 2.0 with support of FAT32 and
charging.
MHL 2.0 with HDMI 1.4
MHL 3.0 with HDMI Type A receptacle
SDXC
Secure Digital Card reader
Audio
Audio hardwire Output
Adjustable gain differential or single
ended audio
Wired Headphones
3.5 mm jack wired headphone output
FM Transmitter
98 channel
Bluetooth Audio profile
Bluetooth audio profile support
(A2DP)
IR Headphone Output
Analog IR headphones
System Control
IR Remote Control
IR remote control
Bluetooth profile AVRCP 1.5
Bluetooth remote control with feedback
IP Remote control
IP remote control will be app based
Auxiliary Monitor Control
Control of EVO 0
FCC Remote Control
Button To Speech function from remote
Digital media playback
High-Level Processor
Multimedia Engine
Supported Files and Formats
Refer to Codec List.
Wireless Connectivity
WLAN Network
Create and manage WLAN Access Point
Miracast Receiver
Miracast destination point
Multicast Streamer
Create a A/V media cast for multiple
destinations
DLNA Renderer
DLNA destination point
[0000]
TABLE 3
EVO5 Feature Matrix
EVO5 Feature Matrix
Feature
Description
Display Panel
High Resolution Display Panel
Connectivity
DVD
DVD/CD loader
USB 2.0
USB 2.0 with support of FAT32 and
charging.
MHL 3.0 with HDMI 1.4
MHL 3.0 with HDMI Type A receptacle
SDXC
Secure Digital Card reader
Audio
Audio hardwire Output
Adjustable gain differential or single
ended audio
Wired Headphones
3.5 mm jack wired headphone output
FM Transmitter
98 channel
Bluetooth Audio profile
Bluetooth audio profile support
(A2DP)
IR Headphone Output
Analog IR headphones
System Control
IR Remote Control
IR remote control
Bluetooth profile AVRCP 1.5
Bluetooth remote control with feedback
IP Remote control
IP remote control will be app based
Auxiliary Monitor Control
Control of extension monitor
FCC Remote Control
Button To Speech function from remote
Digital media playback
High-level Processor
Robust processing architecture
Multimedia Engine
Refer to agreed-upon Codec license listing
Wireless Connectivity
WLAN Network
Create and manage WLAN Access Point
Miracast Receiver
Miracast destination point
Multicast Streamer
Create a A/V media cast for multiple
destinations
DLNA Renderer
DLNA destination point
[0037] A detailed description of certain elements of the above feature matrixes and/or other parts of the EVO 0, 4 and 5 monitors will now be described.
Processors and Decoders
[0038] (EVO0)—may not have the ability to decode media content; may not have system-on-chip (SOC) or SOM architecture; may only have microprocessors needed to perform features of its feature Matrix.
[0039] (EVO4/5)—Full iMX6 based SOC or SOM may be used, e.g., iMX6 dual core Freescale SOC; have an operating system, e.g., Android 5.1; have a boot sequence; boot sequence starts once power is applied (e.g., vehicle ignition on) to the system component; capable of digital media playback.
USB Dedicated Charge Port (DCP)
[0040] USB type A receptacle shall be used. Power requirements support 10 watt charging criteria as outlined in USB Version 2.0 specification. Charging is enabled upon vehicle ignition being turned on. Charging device support fits the following criteria: supports Apple specification for iPhone charging; supports Apple specification for iPad charging; supports charging android phone devices; is able to reduce charging from 10 W upon demand to manage max current draw of the system (e.g., during temporary peak current draw conditions) and under low vehicle voltage conditions.
USB Charging Downstream Port (CDP)
[0041] USB 2.0 Read and Write—USB Version 2.0 specification compliant; USB type A receptacle shall be used; supports FAT32, NTFS, and exFAT file systems; USB feature supports both read and write as outlined in the USB 2.0 specification; supports up to a 1 TB USB drive.
[0042] USB Content sourcing—USB content is able to be sourced between system components; USB content sourced from another system component is able to play simultaneous on both system components without any A/V sync issues.
Mobile High-Definition Link (MHL)
[0043] MHL 2.0—MHL Version 2.0 specification compliant; MHL certified; HDMI Type A receptacle shall be used (e.g., 13.9 mm×4.45 mm); HDCP compliant; HDMI 1.4 compliant; charging shall support 10 watt device charging as outlined in MHL 2.0 specification.
[0044] Content sourcing—MHL content is able to be shared from EVO 4/5 to EVO 0; MHL content sourced from another system component shall be able to play simultaneously on both system components without any A/V sync issues.
HDMI
[0045] HDMI 1.4—version 1.4 specification compliant; HDMI certified; type A receptacle shall be used (e.g., 13.9 mm×4.45 mm); HDCP compliant.
[0046] Content sourcing—HDMI content is able to be shared from EVO 4/5 to EVO 0; HDMI content sourced EVO 4/5 to EVO 0 is able to play simultaneously on both system components without any A/V sync issues.
SD Card
[0047] SDXC (exFAT)—SDXC supports exFAT, NTFS, and FAT32 file systems; uses Standard SD Card receptacle (e.g., 32 mm×24 mm); supports read and write as outlined in the SDXC specification; supports a variety of file formats; supports up to a 512 GB SDXC card.
[0048] SDXC Content sourcing—SD content can be shared from EVO 4/5 to EVO 0; SD content sourced shared from EVO 4/5 to EVO 0 is able to play simultaneously on both system components without any A/V sync issues.
Wired Headphones
[0049] Receptacle—output receptacle shall use 3.5 mm TRRS phone connector; TRRS CTIA/AHJ standard compliant; contains a normally closed switch contact.
[0050] Audio output control—wired headphone audio output will have a volume control on the monitor display; wired headphone audio volume output shall be controlled by the remote control function and on screen display; wired Headphone audio volume output shall be controllable via an in-context audio selection in the player software, invoked by a “menu command”; shall support for apple in-line volume control enabled headphones. Example headphones are Klipsch R6i in-Ear Headphones; wired headphone audio output volume shall default to factory setting on any condition of a power cycle.
FM Transmitter
[0051] Can support 98 channel FM frequency, Channel resolution is 200 KHz; starting at 88.3 MHz; ending at 107.7 MHz.
[0052] Antenna shall route out of monitor assembly and be removable from the system component with VHC approved connector.
[0053] FM antenna can be included with the system component but is not necessary.
[0054] Functionality—shall be configured in firmware to be enabled and disabled on the system component according to system profiles; FM transmitter settings shall be available in a settings menu on the home screen; enabling and disabling the feature functionality shall be performed from the settings menu as well as an in-context audio selection in the player software, invoked by a “menu command”; changing FM frequency shall be performed from the settings menu as well as an in-context audio selection in the player software, invoked by a “menu command”; a hidden menu can be used to adjust the FM transmitter signal strength.
Bluetooth Connectivity
[0055] Bluetooth General Functionality—Bluetooth shall meet Specification v2.1+EDR at a minimum; Bluetooth settings shall be available in a settings menu on the home screen; enabling and disabling the feature functionality shall be performed from the settings menu as well as an in-context selection in the player software, invoked by a “menu command”; pairing Devices to the system shall be performed from the settings menu; Bluetooth connectivity shall work as a master device as outlined in the Bluetooth specification; Bluetooth connectivity shall also work as a slave device as outlined in the Bluetooth specification; feature shall be configured in firmware to be enabled and disabled on the system component according to system profiles.
Bluetooth Advanced Audio Distribution Profile (A2DP)
[0056] Bluetooth connectivity shall support stereo audio streaming to Bluetooth enabled devices via A2DP; Audio volume once paired shall default to 40 dB+−3 dB @ 1 kHz as measured at the drivers of headphones; Volume controls shall default to Bluetooth while Bluetooth is active; Volume changes made to any other audio output shall have no effect on the Bluetooth volume; Enabling wired headphones shall not disable Bluetooth A2DP; Enabling Bluetooth A2DP shall not disable wired headphones; Enabling IR headphones shall not disable Bluetooth A2DP; Enabling Bluetooth A2DP shall not disable IR headphones; Audio shall have the ability to compensate for the encoding/decoding delay and be synced with video within 10 microseconds; APT-X codec will be used to achieve low-latency.
Bluetooth Audio/Video Remote Control v 1.5 Profile (AVRCP)
[0057] Bluetooth connectivity shall support Audio/Video Remote Control v 1.5 Profile (AVRCP). The use of Bluetooth controls shall not disable IR controls. The use of IR controls shall not disable Bluetooth controls. Bluetooth controls shall perform the same functions as an IR remote control. Bluetooth QWERTY keyboard shall be supported anywhere text input in needed in the GUI.
IR Headphone
[0058] IR Analog Headphones shall be used with the following frequencies configured in firmware on the system component according to system profiles. For example, Master profile (EVO4/5): Left Channel 2.3 MHz, Right Channel 2.8 MHZ. For example, Satellite profile(EVO0): Left Channel 3.2 MHz, Right Channel 3.8 MHZ.
[0059] Enabling wired headphones shall not disable IR headphones. Enabling IR headphones shall not disable wired headphones. Enabling Bluetooth A2DP shall not disable IR headphones. Enabling IR headphones shall not disable Bluetooth A2DP. System component may have no IR headphone volume control. IR receiver may not be obstructed by any part of the system component in direct line of sight viewing position. IR Headphone output shall support the headphones.
IR Remote Control
[0060] NEC protocol shall be used. IR Remote shall have the ability to store two remote profiles on board, one for master system component and one for satellite system component. IR Remote shall be able to switch between remote profiles using Monitor A and Monitor B selection buttons. IR remote buttons shall support long press commands. IR remote output shall support the remote.
Audio Hardwired Output
[0061] Adjustable Gain Single Ended and Differential Audio—
[0062] Adjustable gain single ended audio shall be supported. Single ended gain shall have an adjustable range of 0V to 4V peak to peak and a resolution of 0.2 V. Setting of adjustable peak to peak voltage shall be configured in firmware.
[0063] Adjustable gain differential audio shall be supported. Differential audio gain shall have an adjustable range of 0V to 4V peak to peak and a resolution of 0.2 V. Setting of adjustable peak to peak voltage shall be configured in firmware.
[0064] Adjustable gain feature shall be configured in firmware to be enabled and disabled on the system component. Adjustable gain feature shall be configured in firmware to choose the audio type (single ended or differential).
Graphical User Interface (GUI) and On-Screen Display (OSD)
[0065] GUI may have the exact same visual appearance on all system components. GUI operation and layout may be exact same on all monitors. Navigation of GUI shall be handled by D pad arrows, select button, menu button and back button. All functions of the GUI shall be accessible in context specific OSD menus invoked with a menu button.
[0066] On screen QWERTY keyboard shall be supported anywhere text input in needed in the GUI. On screen QWERTY keyboard shall be handled by D pad arrows, select button, menu button and back button. From any status location in the GUI a press of the home button shall pause content playback and bring the GUI to the home screen. GUI shall support the following languages in all visible text to the end user: English, French, Spanish, Chinese (Both Traditional and Simplified), Arabic.
On-Screen Display (OSD)
[0067] OSD may have the exact same visual appearance on all monitors. OSD shall be context specific and only display content relevant to the current state of the device. OSD shall support the following languages in all OSD menus: English, French, Spanish, Chinese (Both Traditional and Simplified), Arabic.
Supported Files and Formats
[0068] Supported file formats, codecs and containers shall support those outlined below. For example, the infotainment system shall support the following formats: Video: AVI (Xvid, h.264/MPEG-4 Part 10 [AVC], MPEG/2/4); MPG/MPEG; VOB; MP4 Part 14 (MPEG4, h.264/MPEG-4 Part 10 [AVC]), MKV (h.264, h.264/MPEG-4 Part 10 [AVC], MPEG/2/4, VC-1), Photo: JPEG, BMP, PNG, Audio: MP3, ACC, WMA, MPEG-1, MPEG-2, AC-3, Subtitle: SRT, SSA, SUB
[0069] The infotainment system can also support the following formats: Video: FLV (Sorenson H.263), TS/TP/M2T (MPEG1/2/4, AVC, VC-1), MOV (MPEG4, h.264/MPEG-4 0Part 10), M2TS, WMV9, Photo: TIF/TIFF, GIF, Audio: WAV, Dolby Digital Plus, OGG; MKA; FLAC; DTS, Playlist: M3U.
WLAN
[0070] WLAN functionality shall be Wi-Fi certified. Infotainment device shall have the ability to create and control a unique WLAN network with a unique SSID (Access Point Mode; AP mode). WLAN SSID shall broadcast and be able to be joined by devices with supported network and encryption standards. Infotainment device can work in only one mode at a time (AP, Client Mode). Infotainment device shall have the ability to switch between AP mode and Client mode by the end user via the settings menu. Client mode shall be activated or deactivated by a toggle or radio button in the wireless section of the settings.
[0071] WLAN network shall assign internet protocol addresses (IP address) according to IPv4 standard via a DHCP server. WLAN shall be able to connect and manage Wi-Fi capable devices while in AP mode without limitation to how many. WLAN will deny access to the AP once 10 Wi-Fi capable devices have successfully connected. If access is denied WLAN shall alert devices trying to connect to the AP after it has meet its limit with clear language indicating the limit has been meet. WLAN network shall operate simultaneously in dual band mode in the 2.4 GHz and 5 GHz frequency band. WLAN and Wifi Direct (Miracast) shall be Real time Simultaneous dual band.
[0072] Concurrent WiFi Direct and Access Point Services. Example configuration: WLAN SSID shall be configured in firmware on the system component. All WLAN AP settings shall be configured in firmware on the system component. WLAN AP settings shall have the ability to be managed via a web interface.
[0073] Encryption: Supported Encryption types: WLAN may support network access via 64-bit WEP. WLAN may support network access via 128-bit WEP. WLAN shall support network access via WPA-PSK. WLAN shall support network access via WPA2-PSK. General Encryption features: Encryption shall be configured in firmware. Encryption password shall be configurable by the end user via the settings menu. WLAN shall maintain a log of all previously authenticated Wi-Fi capable devices by main access control address (MAC) and allow reconnection of these devices without the need for re-authentication.
[0074] Networking standards: Shall support IEEE 802.11n-2009. Shall support IEEE 802.11g-2003. Shall support IPv4. Shall support IPv6.
[0075] Data Rate: WLAN network shall have a minimum optimal data rate (Herby: MODR) suitable to stream up to 2 high definition video streams and receive commands from 2 ip-remotes in all frequency bands supported. Wireless network data rates shall be support desired use cases.
[0076] Coverage: WLAN coverage in all supported frequency bands to reach all devices inside the vehicle.
[0077] Network utilities: WLAN shall support Wi-Fi Multimedia (WMM). WLAN shall support Quality of Service Utility (QoS). Infotainment network will not block UPnP, DLNA, and Multicast.
Miracast Receiver
[0078] Miracast receiver functionality shall be Wi-Fi Alliance certified. Miracast functionality shall act as a Miracast receiver (WFD Sink) as specified in Wi-Fi Display Technical Specification Version 1.1. Miracast receiver functionality shall be HDCP 2.1 compliant.
[0079] General features: Miracast shall support both Audio and Video transmission. Miracast shall be configured in firmware on the system component. Miracast shall be a source input represented and selectable in all source input locations in the GUI. Miracast functionality shall not disrupt the status of any other device feature unless otherwise stated. Miracast shall perform the exact same regardless the mode the WLAN feature is in (AP or Client mode). WLAN and (Miracast) shall be Real time Simultaneous dual band.
[0080] Concurrent Access Point Services. Miracast Content sourcing: Miracast content shall be able to be sourced between system components. Miracast content sourced from another system component shall be able to play simultaneously on both system components without any A/V sync issues.
Multicast Streamer
[0081] Multicast General features: Multicast shall support a one-to-many network assisted distribution method. Multicast may perform its group communication using RTSP, RTP, RTCP, +Unicast. Multicast may perform its group communication using IP multicasting. Multicast functionality shall not stream protected content without the required Digital Rights Management (DRM) and content protection for said content. Multicast content shall be restricted to displaying only the content that is being played on the system component the stream is originating from. Multicast shall function the exact same regardless the mode the WLAN feature is in (AP or Client mode). Multicast shall always be enabled and streaming compatible content being played on multicast enabled system component to the available group. Multicast stream shall use a file format and codec that is universally playable from all iOS and Android devices. Multicast streaming shall be accessible from co developed applications for iOS and Android devices.
[0082] Multicast Content sourcing: Multicast content shall be able to be sourced by up to 2 devices connected to the active network the system component is connected to. All Multicast content streamed on compatible devices shall be able to play simultaneously without any A/V sync issues. Device-to-device latency shall be Xms maximum. All Multicast content streamed on compatible devices shall be able to play simultaneously without any A/V sync issues among all devices streaming the content. Device-to-device latency shall be Xms maximum.
Monitor Sharing
[0083] Monitor sharing makes content being displayed on one system component available to another. Monitor sharing does this by displaying all content being rendered on the source system component to the screen of a connected system component through a wired connection, for example.
Full Monitor Sharing
[0084] Full Monitor Sharing mode shall be configured in firmware on the system component. Only content which is being actively viewed on the source system component shall be shared to the other system component. Content being sourced from one source to another shall have no latency in the Video and Audio feed. Device to Device Latency shall be Xms maximum. If content is unavailable for streaming the “monitor sharing” source shall be greyed out and not selectable on the home screen. If a stream becomes unavailable during playback a screen informing the user of the error shall be displayed for 15 seconds then return to the home screen.
Auxiliary Monitor Control
[0085] Auxiliary monitor control enables an equipped system component to extend its feature set to an extension mode system component. System components which control extension monitors shall have enough resources to comfortably control two system components user experience and have resources to spare. Equipped system components referred in this section as “Master.”
[0086] Master shall power up automatically after switched power is applied. Control of both system components shall be identical, independent and controlled by Masters. All Masters equipped and configured I/O shall be available to both system components. Masters shall update attached extension mode firmware via GMSL de-serializer low level line during update procedure. The UX/UI of both system components shall be exactly the same.
[0087] Sources which are independent in nature (e.g. HDMI, DVD, etc.) may be limited to single input source. E.g., Master is equipped with HDMI and extension is not, only one HDMI source is available to be sourced from both system components. Sources which are not independent in nature (e.g. USB, SD, etc.) shall not be limited to single input source. E.g., Master is equipped with USB and extension is not. Multiple movies stored on the USB device shall be available to play independently on Master and extension.
[0088] Master shall interpret commands sent via the low level GMSL communication and execute actions. E.g., Extension is equipped with IR receiver for remote control commands. Any commands are to be passed to Master for execution of extension UX/UI.
DLNA
[0089] System components with DLNA enabled shall be DLNA certified.
[0090] Digital Media Renderer—A digital media renderer is a device used in the DLNA protocol as a content sink. Renderers are sinks that can play music, videos and pictures sent to it from a media controller. A renderer is not able to browse for media on network media servers. A system component shall be certified as a DLNA renderer. DLNA renderer shall be accessible from the home screen as a source (UI dependency). DLNA renderer shall be configured in firmware on the system component.
[0091] Referring now to FIGS. 1 and 2 and the discussion above, it can be seen that the Master (e.g., EVO 4 or 5) can receive a variety of content from a variety of sources. Moreover, the Master can distribute this content to a variety of destinations. For example, by virtue of its I/O connectivity, the Master can receive audio/video content via its USB port and HDMI/HML port. The Master can also receive audio/video content from an SD card, DVD or WiFi connection. This content can then be stored at the Master and/or distributed to other electronic components. This distribution may occur via a wired connection (e.g., GSML cable in FIG. 2 ) or wirelessly. Content may be transferred in a high-speed, high definition digital media manner.
[0092] For example, as shown in FIG. 2 , content may be wirelessly provided to mobile devices 1 and 2 (e.g., smartphones, tablets, etc.). The Master may provide content to one or both of the mobile devices 1 and 2 . This content may be provided wirelessly, independently and/or simultaneously. Similarly, the Satellite may provide content to one or both of the mobile devices 1 and 2 . This content may be provided wirelessly, independently and/or simultaneously. In other words, the infotainment system according to an exemplary embodiment of the present invention has the ability to share multiple content streams to any screen in the vehicle. The infotainment system according to an exemplary embodiment of the present invention can integrate with vehicle built-in screens as well as tablets and smartphones. Moreover, by using the infotainment system according to an exemplary embodiment of the present invention—content from one device (e.g., Mobile device 1 ) can be shared with another device (e.g., Mobile device 2 ) thru the Master. In this way, the Mater functions as an access point or a hub, for example.
[0093] For example, the mobile device 1 and the Master may share content bi-directionally thru DLNA. Further, the Master may Miracast content from the mobile device 2 . Further, the mobile devices 1 and 2 may have an app that enables them to control all functionality of the Master. This control may be done via Bluetooth, for example. In addition, the mobile devices 1 and 2 may be physically wired to the Master to display selected content on the Master's screen. That selected content may also be mirrored to the Satellite's screen. Further, the Master may access both live TV and recorded home cable/satellite TV and stream this to the mobile devices 1 and 2 as well as the Satellite thru an in-car WiFi network, for example.
[0094] The GUI on the Master's screen may be used to bring content into the vehicle from the home (e.g., via a WiFi connection), to set up screen monitoring and/or to set up content streaming. For example, via the GUI, a user may select content from the SD Card and share this content to the Satellite. Further, via the GUI, a user may enter a playback mode to watch something playing on the Master on the mobile device, or make this content play on more than one electronic device.
[0095] FIG. 3 illustrates a wiring diagram of a system according to an exemplary embodiment of the present invention. In FIG. 3 , Monitor A may be the Master device and Monitor B may be the Satellite device; however, the present invention is not limited thereto. At least one of the coax cables may be the GSML cable, for example.
[0096] FIG. 4 is a circuit diagram of a satellite device according to an exemplary embodiment of the present invention. The satellite device may include the circuit elements in Table 4 to implement the features described above therefor.
[0000]
TABLE 4
M0516LDN
MCU
FM-3038TM2-5DN
IR-RECEIVER
MAX9278
GMSL
MAX9850
AUDIO DECODER
AST0222DE
IR TRANSMITTER
[0097] FIGS. 5A and 5B show a circuit diagram of a master device according to an exemplary embodiment of the present invention. The master device may include the circuit elements in Table 5 to implement the features described above therefor.
[0000]
TABLE 5
iMX6D
Application processor
AST0222
IR Transmitter
TW9900
Y/C Video CVBS
NT5CC128M16IP-DII
DDR 3
EMMC08G-W100-A06
eMMC 8 Gb
WL1837MOD
Wifi & BT Module
M0516
MCU
SGTL5000
Audio Codec
TPA6132
AUDIO AMP headphone 2
CH
SN74CBTLV3257PWR
Low Voltage
HA5266
Multiplexer/Demultiplexer
MP3305
LED BACKLIGHT
InnoLux ZJ080NA-08A
TFT-LCD 8″ Panel
MAX9277
Serializers
MP62551
MHL 2.0 Charger 1A
IT6802E
HDMI PO
SLGC55544
USB IC
[0098] Although the present invention has been shown and described with reference to exemplary embodiments thereof, it is understood by those of ordinary skill in the art that various changes in form and detail can be made thereto without departing from the spirit and scope of the present invention as hereinafter claimed.
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A rear seat entertainment system includes an access point and a second housing. The access point includes a first screen and input/output ports. The access point is included in a first housing. The second housing is separate from the first housing and includes a second screen. The access point is configured to display first content on the first screen and stream the first content displayed on the first screen to the second housing so that the first content is displayed on the first and second screens. The access point is further configured to receive second content from a mobile device, display the second content on the first screen and stream the second content displayed on the first screen to the second housing so that the second content is displayed on the first and second screens.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a divisional of co-pending, commonly assigned U.S. patent application Ser. No. 10/141,348, filed on May 9, 2002, which is incorporated by reference herein in its entirety.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to a medical device for providing a change of shape in a part of the body of an organism. The invention further relates to a device and a method for reshaping a body vessel, and a device and a method for restraining growth of a body organ of an organism.
BACKGROUND OF THE INVENTION
[0003] At present the treatment of mitral annulus dilatation and other mitral insufficiencies consists of either repair or mitral valve replacements. Both methods require open-heart surgery, by the use of total cardiopulmonary by-pass, aortic cross-clamping and cardioplegic arrest. To certain groups of patients, open-heart surgery is particularly hazardous and therefore a less invasive method for repair of mitral insufficiency is desired.
[0004] Such a less invasive method is proposed in U.S. Pat. No. 6,210,432, which describes a method for treatment of mitral insufficiency without the need for cardiopulmonary by-pass and opening of the chest and heart. The method uses a device comprising an elongate body having such dimensions as to be insertable into the coronary sinus, which is a vein that substantially encircles the mitral orifice and annulus and drains blood from the myocardium to the right atrium. The elongate body has two states, in a first of which the elongate body has a shape that is adaptable to the shape of the coronary sinus, and to the second of which the elongate body is transferable from said first state assuming a reduced radius of curvature. Consequently, the radius of curvature of the coronary sinus is reduced. Due to the coronary sinus encircling the mitral annulus, the radius of curvature as well as the circumference of the mitral annulus are reduced. Thus, the described method takes advantage of the position of the coronary sinus being close to the mitral annulus, which makes repair possible by the use of current catheter-guided techniques.
[0005] According to one method described in U.S. Pat. No. 6,210,432, a device comprising an elongate stent is used. The elongate stent includes hooks which are arranged to dig into the walls of the coronary sinus, by means of the surgeon retracting a cover sheet from the stent, in order to fix the position of the stent in the coronary sinus. A stabilizing instrument is used for keeping the elongate stent in its first state and then, after the hooks have dug into the walls, releasing it to its second state assuming a reduced radius of curvature. However, the position fixation of the elongate stent in the coronary sinus by means of the hooks might be insufficient, so that the sudden release of the contraction of the elongate stent dislocates it. This dislocation of the device might result in unsatisfactory reduction of the circumference of the mitral annulus.
[0006] According to an alternative method described in U.S. Pat. No. 6,210,432 the device comprises three stent sections that are positioned in the coronary sinus and connected by wires. The wires may be maneuvered from outside the vein system such that the distances between the adjacent stent sections are reduced. Also with this method there is a risk of dislocation of the device, since the surgeon might accidentally move insufficiently fixed stent sections out of their proper position while manipulating them from outside the vein system.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide a more secure fixation of a medical device for providing a change of shape in a part of the body of an organism.
[0008] A particular object of the invention is to provide a more secure fixation of a device for reshaping a body vessel, as described above.
[0009] These and other objects are achieved by a device and method as defined in the claims.
[0010] More particularly, according to one aspect of the present invention, a medical device being insertable into the body of an organism comprises a member having a preferred state of shape, towards which the member by means of inherent forces strives when being in a non-preferred state of shape, and a delay means having a weakenable inherent stiffness to hold the member in the non-preferred state of shape for a period of time after the device is inserted into the body of the organism. The member is by means of said inherent forces arranged to provide a change of shape in a part of the body of an organism, whereas the delay means is arranged to delay the change of shape for a period of time. The time period is determined by how fast the weakening of said inherent stiffness proceeds. By delaying the change of shape this way, the device is allowed to heal on to body tissue of the organism before a change of shape of the device occurs. Which parts of the device that become fixed by the healing process can be determined by means of the design of the device. The normal healing process that occurs in every living organism is thus allowed to provide a well-established fixation of the device. Hence, the present invention provides a more secure fixation of a medical device for providing a change of shape in a part of the body of an organism.
[0011] In a preferred embodiment of the invention, said delay means holds said member in a non-preferred state of shape by counteracting the inherent forces of the member. Thus, the delay means is arranged to apply force to the member by means of the inherent stiffness, in order to counteract the inherent shape-changing forces of the member and thereby restrain the member from changing its shape.
[0012] Preferably, said delay means holds said member in a non-preferred state of shape while the inherent stiffness of the delay means overcomes the inherent forces of the member. That is, there is an equilibrium between the inherent forces of the member and the inherent stiffness of the delay means, and when the stiffness of the delay means no longer is strong enough to balance the inherent forces of the member, the change of shape will occur.
[0013] In another preferred embodiment of the invention, said delay means comprises a decomposable material. In this way, the inherent stiffness of the delay means is allowed to weaken simply as a result of the decomposable material of the delay means being decomposed.
[0014] Preferably, said delay means comprises a resorbable material. A resorbable material is a material that when it is inserted into the body of an organism, it will be resorbed by the body by means of enzymatic processes, by active absorption by the cells in the blood and tissue cells of the body, and/or by hydrolysis. Thus, the resorbable material of the delay means will advantageously be decomposed and vanish from the device by time, without leaving any major waste products in the body.
[0015] In another preferred embodiment, said member comprises an elastic material. An elastic material can in a simple way be forced to adopt a non-preferred shape.
[0016] In yet another preferred embodiment, said member comprises a material having superelasticity properties. Superelasticity properties means that the material may be deformed and in the deformed state the material will use its superelasticity forces to return to its preferred shape. These superelasticity forces thus constitute advantageously at least part of said inherent forces providing said strive towards said preferred state of shape of the member.
[0017] Preferably, said member comprises a shape memory material. A shape memory material is a material that has two different forms, one at lower temperatures and another at higher temperatures. At the lower temperatures, e.g. below 30.degree. C., the material is elastic and may be introduced into the body. At the higher temperatures, the material is still elastic but becomes also superelastic and assumes its preferred original shape unless the transformation to this original shape is obstructed by external stress to the material. The use of a shape memory material in the member is advantageous inter alia because then one can easily provide the device with said delay means while the member, at a lower temperature outside the body, more easily remains in a shape corresponding to said non-preferred state of shape inside the body.
[0018] According to another aspect of the present invention, a medical device for providing a change of shape in a part of the body of an organism comprises a first set of forces working towards a change of shape of the device, and a second set of forces working for preserving a present shape of the device and thereby counteracting said first set of forces. Said first and said second sets of forces are each inherent in a solid material of the device, and the forces of said second set of forces are arranged to decrease as a result of said solid material interacting chemically with said part of the body. As a result of the chemical interaction between the solid material of the device and the surrounding body, the forces of the second set of forces decrease and thus allow the device to provide said change of shape after a while, when parts of the device have become fixed in the body by a healing process. An advantage of the present invention, except that it provides a more secure fixation, is that there is no need for a stabilizing surgical instrument for keeping a present shape of the device during operation, since the shape is preserved by means of said second set of forces being inherent in the device itself.
[0019] Preferably said second set of forces is inherent in a decomposable material as mentioned above.
[0020] Said forces of said second set of forces are preferably arranged to decrease as a result of said solid material being decomposed by said part of the body.
[0021] In a preferred embodiment of the invention, said second set of forces is inherent in a resorbable material as described above.
[0022] Preferably, said forces of said second set of forces are arranged to decrease as a result of said solid material being resorbed by said part of the body.
[0023] In another preferred embodiment, said first set of forces is inherent in an elastic material.
[0024] Preferably, said first set of forces is inherent in a material having superelasticity properties as described above.
[0025] Said first set of forces is preferably inherent in a shape memory material as also described above.
[0026] In one embodiment of the invention, said first set of forces is inherent in a shape memory metal.
[0027] In an alternative embodiment of the invention, said first set of forces is inherent in a shape memory polymer.
[0028] The device is in one embodiment arranged to contract into a new shape as a result of said second set of forces being decreased.
[0029] In an alternative embodiment, the device is arranged to expand into a new shape as a result of said second set of forces being decreased.
[0030] The device could be arranged to change its shape in one dimension only, but it could also be arranged to change its shape in two dimensions, or even in three dimensions.
[0031] According to yet another aspect of the present invention, a medical device being insertable into the body of an organism comprises a member having a preferred state of shape and having a tendency to transfer its shape towards said preferred state of shape when being in a non-preferred state of shape. The device further comprises a resorbable means being arranged to hold the member in the non-preferred state of shape and to delay the transfer when the device is inserted into the body of the organism by counteracting said transfer during resorption of the resorbable means by the surrounding body of the organism. The resorption of the resorbable means by the surrounding body makes the resorbable means gradually vanish. Thus, after some period of time when parts of the device have grown on to body tissue, there is nothing left to hold the member in the non-preferred state of shape, whereby said transfer is released.
[0032] Also according to this aspect of the invention, said member preferably comprises an elastic material.
[0033] Preferably, said member comprises a material having superelasticity properties.
[0034] It is also preferred that said member comprises a shape memory material.
[0035] According to a particular aspect of the present invention, a device for reshaping a body vessel is elongate and has such dimensions as to be insertable into the vessel and has two states, in a first of which the device has a shape that is adaptable to the shape of the vessel, and to the second of which the device is transferable from said first state. The device further comprises a fixing means for fixing the ends of the device within the vessel, when the device is first positioned therein, a member for transferring the device to the second state by reshaping it, and a resorbable means for delaying said reshaping until the ends of the device are fixed by keeping said device in said first state until the resorbable means is resorbed. By allowing the ends of the device to heal on to the walls of the vessel, e.g. the coronary sinus, by means of said fixing means, before said reshaping of the device occurs, the present invention provides a more secure fixation of a device for reshaping a body vessel.
[0036] Preferably, said resorbable means comprises a resorbable sheath being arranged to enclose said member. This is advantageous since with the shape of a sheath the resorbable means is both easy to manufacture and easy to arrange on the member.
[0037] In another preferred embodiment of the invention, said fixing means is arranged to expand against the wall of the vessel when first positioned therein. This expansion against the wall of the vessel initiates and contributes to the fixing of the ends of the device, thus enabling a rigid fixing.
[0038] In yet another preferred embodiment of the invention, said fixing means is arranged to grow into the wall of the vessel. By taking advantage of the healing process in the tissue of the vessel wall, the fixing means can be fixed effectively. This can be facilitated by an expansion against the wall of the vessel as mentioned above.
[0039] In a preferred embodiment, said fixing means comprises a self-expandable stent at each end of the device.
[0040] According to another preferred embodiment, said member comprises a shape memory material providing said reshaping of the device.
[0041] Preferably, said reshaping of said device comprises shortening of said device.
[0042] In another preferred embodiment, said device is used for treatment of mitral annulus dilatation. Since the device can be inserted into a body vessel using catheter-guided techniques, the use of this device for treatment of mitral annulus dilatation is advantageous compared to open-heart surgery, which is the present procedure for repairing or replacing the mitral valve.
[0043] In yet another preferred embodiment, said vessel is the coronary sinus. The coronary sinus encircles the mitral orifice and annulus. Therefore, a reshaping of this vein also has a compressing effect on the mitral annulus.
[0044] Preferably, said reshaping of said device is used for reducing the radius of curvature of the coronary sinus. Hence, the radius of curvature as well as the circumference of the mitral annulus are also reduced. According to the invention, a method for reshaping a body vessel comprises the steps of inserting a device into the vessel, fixing the ends of the device within the vessel, reshaping the device, and delaying said reshaping by a resorbable means so that the step of fixing the ends of the device is performed before the step of reshaping the device.
[0045] According to a preferred embodiment, said step of fixing the ends of the device comprises providing a growth of the ends into the wall of the vessel.
[0046] According to another preferred embodiment, a shape memory material is used in the device for said step of reshaping the device.
[0047] Preferably, Nitinol is used in the device for said step of reshaping the device.
[0048] In a preferred embodiment, said step of reshaping the device comprises the step of shortening the device.
[0049] In another preferred embodiment, the method is used for treatment of mitral annulus dilatation.
[0050] In yet another preferred embodiment, said device is inserted into the coronary sinus in the vicinity of the posterior leaflet of the mitral valve.
[0051] Preferably, said reshaping is used for reducing the curvature of the coronary sinus and thereby reducing the radius of circumference of the mitral valve annulus.
[0052] The basic inventive idea, that reshaping of an implantable device may be delayed by means of a delay means being comprised in the device itself, opens up for new possibilities within many medical applications.
[0053] The present invention could be used for instance when a delayed expansion of a stent is desired. The stent could then preferably be crimped to a small diameter by means of a resorbable suture or, alternatively, a resorbable film. The film or thread would slowly be eaten away and the shape-changing forces may be released after the desired delay which is programmed in the properties of the resorbable restraining material. Such a stent might be used inside vessels, the trachea, the biliary tract or any other hollow structure in the human or animal body.
[0054] The invention would also be useful where openings of human, or animal, organs or other structures need to be opened or closed slowly. For instance, when an opening between the left and right side of the heart is present, an immediate closure of the opening could be dangerous, whereas a slower closure would be tolerated.
[0055] Within many medical areas, the present invention would be useful when a continuous long-term effect of shape-changing forces is desired. One such application would be a device designed to shorten or lengthen a human or animal structure in one or more dimensions. The device according to the invention would then have time to heal into the body structure before shape-changing forces are released and force the body structure to slowly change its shape.
[0056] This could for example be useful in the area of orthopedics for lengthening of a bone structure.
[0057] For orthodontic treatment, the described invention would be useful when it comes to tooth-regulation and lengthening of the maxilla and/or mandibula, i.e. the upper and lower jaws.
[0058] In plastic surgery an extra growth of skin area is often used to cover skin defects. Using the present invention a slow growth of skin area would be augmented.
[0059] An example within the area of urology surgery is lengthening of a penis. In this case a device made of three segments could be designed, where the distal ends of the device first are allowed to grow into the tissue. After fixation of the two ends of the device in the penis tissue, the mid portion which temporarily has been restrained by means of a resorbable material as described above will be released and the mid portion of the device will grow in length. One specific capacity of a human or animal body is to allow slow deformation of organs or tissues by compensatory tissue adaptation. A penis would therefore grow slowly to a predetermined length.
[0060] By means of the present invention, a sequential effect of shape-changing forces could also be provided, i.e. change of shape could occur in two or several steps as a result of resorbable material releasing the shape-changing forces in predetermined steps. In each step, a part or parts of a device could first heal into a body structure and secondly the desired shape-changing effects could be released.
[0061] As seen from the examples above, a substantial advantage of the present invention is that a change of shape is allowed to be made slowly so that body tissues have time to adapt.
[0062] Other medical applications of particular interest, which could be improved by using the present invention, are treatment of pathological heart growth and treatment of pathological alveolar sac growth. Some background of these two diseases will be given next.
[0063] Dilated cardiomyopathy (DCM) and ischemic heart disease (IHD) are common reasons for heart failure (HF). Heart failure in its terminal status is a deadly disease, and it is by far the most common cause of death in most countries, developed and undeveloped. Progressive HF, when it is deteriorating, results in a growth in the diameters of the heart ventricles, thus resulting in a general heart growth. The growth in heart size by dilatation initiated by myocardial pathology creates itself by its increase in heart diameter a pathology of its own, in the way of functional disorders.
[0064] Dr. Randas Batista implemented a surgical treatment for this disease by resecting big parts of the left ventricle (LV) with or without repair of the mitral valve. The long time results were, however, dismal since the LV tends to dilate again a second time despite of having been reduced in size by surgery (see Kawaguchi, A. T. et al. “Mitral Regurgitation Redilates the Left Ventricle After Partial Left Ventriculectomy (Batista Operation).” Journal of the American College of Cardiology, February 1998, Vol. 31, No. 2, Suppl. A, page 376A, ISSN: 0735-1097; see also Kawaguchi, A. T. et al. “Intraoperative Left Ventricular Pressure-Volume Relationship in Patients Undergoing Left Ventricular Diameter Reduction.” Circulation, 1997, Vol. 96, No. 8, Suppl., page 1198, ISSN: 0009-7322; and Prez de la Sota, E. et al. “Early Results with Partial Left Ventriculectomy (the Batista Operation).” Revista Espanola de Cardiologia, August 2000, Vol. 53, No. 8, pages 1022-1027, ISSN: 0300-8932).
[0065] Supporting the LV and preventing progressive LV dilatation in HF actively by means of wrapping the heart with living skeletal muscle from the back of the patient, stimulated by pacemaker, was introduced by Dr. Carpentier in the eighties (Chachques, J. C. et al. “Dynamic Cardiomyoplasty: clinical follow-up at 12 years.” European Journal of Cardio-Thoracic Surgery: Official Journal of the European Association for Cardio-Thoracic Surgery, October 1997, Vol. 12, No. 4, pages 560-568, ISSN: 1010-7940). The method has been rarely used and its effectiveness has been questioned.
[0066] More recently, methods of restraining the heart from growing have been introduced by Acorn Cardiovascular, Inc, St. Paul, Minn., USA. They are supporting the heart by means of a polyester mesh sutured to the surface of the heart after exposing the heart by splitting the sternum and opening the pericardium.
[0067] Even reducing the LV diameter by force, using wires that transverse the LV cavity and subsequent fixation, has been introduced by Myocor, Maple Grove, Minn. 55311, USA.
[0068] Chronic obstructive pulmonary disease (COPD) is an umbrella term used to describe airflow obstruction that is associated mainly with emphysema and chronic bronchitis. COPD is the fourth leading cause of death in the U.S. in 1998, according to the National Center for Health Statistics, Report of Final Morbidity Statistics, 1998. Emphysema causes irreversible lung damage by weakening and breaking the air sacs within the lungs. Further, sick air sacs sometimes grow unrestrainedly and repress smaller air sacs, resulting in lack of oxygen and by time death. This disease is hard to treat. At present, surgical treatment of dilated air sacs involves cutting them away, but this treatment gives no long-term effect since a new air sac will soon start to grow.
[0069] All these known methods for treatment of pathological heart growth and said known method for treatment of alveolar sac growth require, whether they are effective or not, major heart or lung surgery which, as mentioned before, is particularly hazardous to certain groups of patients. Therefore less invasive methods for treatment of pathological heart growth and alveolar sac growth are desired as well.
[0070] It is an object of the present invention to also provide less invasive treatments of pathological growth of body organs, by which treatments more long-term effects can be achieved.
[0071] A particular object of the invention is to provide less invasive treatments of pathological heart growth and alveolar sac growth.
[0072] These further objects are achieved by a device as defined in claim 50 and by a method as defined in claim 53 .
[0073] More particularly, according to a further aspect of the present invention, a device for restraining growth of a body organ of an organism is implantable into the body of the organism and comprises an elastic contractable member being arranged to enclose said body organ, and a resorbable means being arranged to delay contraction of the contractable member when the device is implanted in the body of the organism by counteracting the contraction during resorption of the resorbable means by the surrounding body of the organism.
[0074] A basic advantage of the device according to the invention is that the device, since said contractable member is elastic, can be inserted into the body using catheter-guided techniques. Hence, less invasive treatments can be provided.
[0075] Another advantage, which comes both from the elasticity and the delayed contraction, is that the device can be inserted by means of catheter-guided techniques even if said contractable member comprises a large area. This is due to the fact that the substantially elastic device at the insertion can be rolled up on a catheter and then be unfolded to enclose said organ.
[0076] After a period of time after the surgical or percutaneous insertion, the device will start to contract as a result of the resorbable means being resorbed. The contraction will then make the device enclose the organ tight and apply a restraining force which holds back the growth of the organ. Since the implanted device applies a continuous restraining force to the organ, more long-term effects can be achieved in treatment of growing body organs. It is to be noted that if the contraction of the device would not have been delayed, it would have been very difficult to roll up the device on a catheter and then unfold it round the organ.
[0077] Preferably, said contractable member comprises a shape memory material.
[0078] According to the invention, a method for restraining growth of a body organ of an organism comprises the steps of inserting a restraining device into the body of the organism, enclosing at least partly the body organ with the restraining device, compressing said restraining device by means of a contractable member of said restraining device, and delaying said compression by a resorbable means.
[0079] This inventive method could be used not only for treatment of pathological heart growth and alveolar sac growth, but also for treatment of bullous emphysema and for treatment of other body organs growing pathologically.
[0080] A device according to the present invention may be fixed in body tissue by other means in combination with or instead of the healing process allowed by the delaying of the change of shape. Hence, fixing of a device according to the invention may as well be accomplished for example by means of suturing, gluing, clipping or using hooks. These means of fixation would permit a better healing in of the device in the tissue and also prohibit dislocation while healing in.
[0081] As already seen, the number of advantages of the inventive device is large, of which a few are mentioned next. The present invention allows:
[0082] 1. less invasive surgical treatments;
[0083] 2. devices that are properly fixed inside the body by means of parts healing into the body tissue;
[0084] 3. devices to be designed that have multiple purposes;
[0085] 4. eliminating stabilizing surgical instruments for keeping a present shape of the device during operation;
[0086] 5. engineering to decide when a shape-changing action by the device is to take place in the body;
[0087] 6. a change of shape to be made slowly so that body tissue has time to adapt.
[0088] It should be understood that many modifications are possible within the spirit and scope of the invention, which is only limited by the appended claims. A few applications of the invention are mentioned above, of which some will be further described by way of illustration only in the detailed description. However, many other medical areas where the invention might be used will become apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0089] The invention will now be described in more detail with reference to the accompanying drawings, in which
[0090] FIGS. 1-4 are schematic views of the structure and the operation of an embodiment of a device according to the invention, illustrating the principle of delayed shortening;
[0091] FIGS. 5-8 are schematic views of the structure and the operation of another embodiment of a device according to the invention, illustrating the principle of delayed elongation;
[0092] FIG. 9 is a schematic view of another embodiment of a device according to the invention being an alternative to the embodiment shown in FIG. 7 ;
[0093] FIGS. 10 and 11 schematically illustrate another embodiment of a device according to the invention, shown in a first state and a second shortened state, respectively;
[0094] FIGS. 12 and 13 schematically illustrate another embodiment of a device according to the invention, shown in a first state and a second elongated state, respectively;
[0095] FIG. 14 is a schematic view of yet another embodiment of a device according to the invention, shown in a first state;
[0096] FIG. 15 a is a schematic view of another embodiment of a device according to the invention being an alternative to the embodiment shown in FIG. 14 and being shown in a first state;
[0097] FIG. 15 b is a schematic view of a device according to FIG. 15 a , illustrating the structure of a part of the device;
[0098] FIG. 16 is a schematic view illustrating the second state of a device according to FIG. 14 or 15 a;
[0099] FIGS. 17 and 18 are schematic views illustrating another embodiment of a device according to the invention, shown in a first state and a second state, respectively;
[0100] FIG. 19 is a schematic perspective view of a device for two-dimensional contraction according to the invention;
[0101] FIG. 20 is a schematic perspective view of another device for two-dimensional contraction according to the invention;
[0102] FIGS. 21 and 22 schematically illustrate an embodiment of a device according to the invention for treatment of mitral annulus dilatation, shown in a first state and a second shortened state, respectively;
[0103] FIGS. 23, 24 and 25 are schematic views illustrating the positioning, the fixing and the shortening respectively, of a device according to FIG. 21 when used in the coronary sinus;
[0104] FIG. 26 is a schematic perspective view illustrating a part of one possible arrangement of a device according to the invention presenting a reshapable area;
[0105] FIGS. 27-30 are schematic views illustrating the positioning and the contraction of an embodiment of the device according to the invention for treatment of pathological heart growth;
[0106] FIGS. 31 and 32 are schematic views illustrating the positioning of an embodiment of the device according to the invention for treatment of chronic obstructive pulmonary disease.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0107] FIGS. 1 to 4 show the principle of delayed shortening according to the invention.
[0108] In FIG. 1 , a shape-changing member 1 , here in the form of a thread 1 , made of or at least in part including a shape memory material is shown having a curved shape. This shape is the original shape that the shape-changing member 1 “remembers” and will assume when the temperature thereof passes a certain threshold, e.g. exceeds 30.degree. C.
[0109] FIG. 2 shows the shape-changing member 1 of FIG. 1 having been straightened by stretching to a substantially straight shape.
[0110] FIG. 3 illustrates an embodiment of a device according to the invention, where the device is in its non-activated state of shape A. More specifically, by covering the stretched and straight shape-changing member 1 in FIG. 2 with a delay means 2 , here in the form of a tube 2 having a sufficiently small inner cross-section, the stretched shape of the shape-changing member 1 can be maintained even when the device is implanted into a human body and the temperature of the shape-changing member 1 thus exceeds the threshold, e.g. 30. degree. C.
[0111] The delay means 2 may be flexible enough to follow the curves in e.g. vessels, but has a stiffness, here especially in its radial direction, which withstands the shape-changing force of the shape-changing member 1 . Thus, having been implanted into the human body, the shape-changing member 1 of the device will strive towards its original, here curved, shape according to FIG. 1 , but is restrained by the delay means 2 .
[0112] However, by manufacturing the delay means 2 from a resorbable material, the delay means 2 will be resorbed by time and the shape-changing member 1 will resume its original shape when the delay means 2 has been resorbed to such a degree or extent that it cannot restrain the shape-changing member 1 any longer, as schematically illustrated in FIG. 4 . Thus, the device has now “been transformed” from its non-activated long state of shape A ( FIG. 3 ), to an activated, shortened state of shape A′ ( FIG. 4 ), where the device consists essentially of the shape-changing member 1 only.
[0113] The device in FIG. 3 may be manufactured in the following way. The thread 1 of a shape memory material, e.g. with the shape illustrated in FIG. 2 , is programmed to remember the shape illustrated in FIG. 1 by being held in that shape while at the same time being heated to a temperature above said threshold. Upon cooling, beneath the threshold temperature, e.g. down to room temperature, the thread 1 will become more flexible and may more easily be deformed into its previous shape shown in FIG. 2 . In this cooled state, the thread 1 is covered by the resorbable tube 2 , e.g. by threading the tube 2 onto the thread 1 or by forming the tube 2 around the thread 1 . Other embodiments of a device according to the invention may operate and may be manufactured in a corresponding manner. Thus, a shape-changing member of a memory material is first held in a “preferred” state of shape while being heated above a threshold temperature, and then cooled beneath the threshold temperature so that it can easily be deformed into its previous “non-preferred” state of shape. Thereafter, the now “programmed” shape-changing member is “locked” in said non-preferred state of shape by a delay means in such a way that the delay means will obstruct the shape-changing member from resuming its preferred state of shape when being heated again, e.g. in a human body. Referring again to FIG. 3 , the inner radius of the tube 2 must not necessarily be so small that the shape-changing member in the form of the thread 1 cannot move at all in the radial direction. Hence, there may be a small radial play in which the shape-changing member 1 can move without consequently being able to change the length of the device to any larger extent. However, the device in FIG. 3 may also be manufactured with essentially no play between the shape-changing member 1 and the inner side of the delay means 2 , possibly also with a pretension or bias force from the delay means 2 acting on the shape-changing member 1 .
[0114] In order to clearly illustrate the shortening of the device, the curved thread 1 is located to the left in FIG. 4 , but, after its transformation, the thread 1 may just as well be located anywhere along the remaining parts of the tube 2 .
[0115] FIGS. 5 to 8 show the principle of delayed elongation according to the invention.
[0116] In FIG. 5 , a shape-changing member 3 , here in the form of a thread 3 of a shape-memory material, is shown having a straight original shape.
[0117] FIG. 6 shows the shape-changing thread member 3 of FIG. 5 when having been folded to a curved shape.
[0118] FIG. 7 illustrates an embodiment of a device according to the invention comprising a thread as illustrated in FIG. 6 , where the device is in its non-activated state of shape B. By covering the curved shape-changing member 3 with a delay means 4 in the form of a tube 4 of a resorbable material, the curved shape B can be maintained even when the device is implanted into a human body and strives towards its original straight shape.
[0119] As schematically illustrated in FIG. 8 , after implantation into the human body, the delay means 4 is resorbed by time and consequently the shape-changing member 3 will be released to resume its original straight shape B′. Thus, the device has now been transformed from its non-activated short state of shape B ( FIG. 7 ) to an activated, elongated state of shape B′ ( FIG. 8 ).
[0120] In the illustrated embodiments, the length of the shape-changing member 1 ; 3 is substantially unchanged by the transformation, whereas the shape of the shape-changing member 1 ; 3 is changed so that the length of the device is changed.
[0121] According to the invention, the material from which the shape-changing member is made may consist of or at least include Nitinol, which is an alloy composed of nickel (54-60%) and titanium. Small traces of chromium, cobalt, magnesium and iron may also be present in Nitinol. Alternatively, other materials such as Shape Memory Polymers (SMP) could be used as the shape memory material.
[0122] Actually, as far as the present invention concerns, the shape-changing material does not have to be a shape memory material. Any superelastic material would function in most applications. For example stainless steel (and other metals) may also be forced into a non-preferred state of shape by means of a resorbable restraining means.
[0123] Examples of usable resorbable materials from which the delay means may be made, or that are at least included, are PDS (polydioxanon), Pronova (polyhexaflouropropylen-VDF), Maxon (polyglyconat), Dexon (PGA, polyglycolic acid), Vicryl (polyglactin), PLA (polylactic acid), PDLLA (polydexolactic acid), PLLA (pololevolactic acid), starch, different kinds of sugar, butyric acid, collagen, and collatamp.
[0124] Depending on the choice of material, the release of the shape-changing forces may be delayed for a desired period of time. Also design parameters such as the thickness of the resorbable material may be set so that the shape-changing forces are delayed as long as desired. The delay time may vary from e.g. a few days up to several years depending on the application.
[0125] The thickness of the delay means may vary along the device, so that the order in which different parts of the device are released by the delay means may be controlled.
[0126] FIGS. 9 to 20 show some different embodiments of a device according to the invention.
[0127] FIG. 9 shows an embodiment of a device according to the invention being an alternative arrangement of a device for delayed elongation as compared to the device shown in FIG. 7 . Instead of a resorbable tube 4 as in FIG. 7 , the resorbable means comprises resorbable crosslinks 6 which hold the shape-changing member 5 in its curved state of shape and thus the device in its non-activated short state of shape C.
[0128] Resorbable crosslinks 6 ( FIG. 9 ) may also be combined with a tube 4 ( FIG. 7 ).
[0129] FIG. 10 shows an embodiment of a device according to the invention in its non-activated elongate state of shape D. Here, the shape-changing member 7 is scissors-shaped. A delay means 8 in the form of a tube 8 of resorbable material holds the shape-changing member 7 in a stretched, elongated state of shape and, thus, also the device in its elongate state of shape D. When the delay means 8 has been sufficiently resorbed, the scissors-shaped shape-changing member 7 will resume its original non-stretched shape and the device is transformed to its activated short state of shape D′ ( FIG. 11 ).
[0130] FIG. 10 a shows an alternative embodiment of a device according to the invention, where the tube 8 in FIG. 10 is replaced by a delay means in the form of resorbable threads 8 a . The delay means 8 a holds the scissors-shaped shape-changing member 7 a in a stretched, elongate state of shape and, thus, the device in a state of shape corresponding to D in FIG. 10 . Referring to FIG. 11 a , when the delay means 8 a is cut off by means of resorption, the shape-changing member 7 a will resume its original non-stretched shape and the device is transformed to its activated short state of shape corresponding to D′ in FIG. 11 .
[0131] FIG. 12 shows an embodiment of a device according to the invention in its non-activated short state of shape E. A scissors-shaped shape-changing member 9 of the device is held in a short state of shape by means of a delay means in the form of a resorbable thread 10 , and, thereby, the whole device is held in its short state of shape E. When the delay means 10 is cut off by means of resorption, the shape-changing member 9 will resume its original elongate shape so that the device is transformed to its activated state of shape E′ ( FIG. 13 ).
[0132] FIG. 14 shows an embodiment of a device according to the invention comprising a shape-changing member in the form of a coil 11 of a shape-memory material having been stretched and arranged in a delay means in the form of a tube 12 of resorbable material. The device is then in its non-activated state of shape F. When the delay means 12 has been sufficiently resorbed, the shape-changing member 11 will resume its original shorter and wider shape as shown in FIG. 16 , and the device is transformed to its activated state of shape F′.
[0133] In an alternative embodiment shown in FIGS. 15 a and 15 b of a device according to the invention, the tube 12 in FIG. 14 is replaced by a resorbable rod 13 provided with grooves 13 a in which a coil 11 is initially wound. The winding of the coil 11 in the grooves 13 a obstructs the coil 11 from resuming its original shape ( FIG. 16 ) and, hence, the device is held in its non-activated state of shape G by the rod 13 , as illustrated in FIG. 15 a . By resorption of the rod 13 in e.g. a human body, the shape-changing force of the coil 11 is released and the device is transformed to its activated state of shape G′ as shown in FIG. 16 .
[0134] In another embodiment shown in FIG. 17 of a device according to the invention, a coil 14 is wound around a resorbable rod 15 . When the rod 15 is resorbed, the shape-changing forces of the coil 14 will be released so that the coil 14 resumes an original elongate shape, as shown in FIG. 18 , whereby the device is transformed from its non-activated state of shape H to its activated state of shape H′.
[0135] FIG. 19 shows an embodiment of a device according to the invention in the form of a patch for closing or obstructing openings, e.g. in the heart of a human or animal body. The patch has a shape-changing member 16 comprising a grid matrix formed by threads made of memory material such as Nitinol or SMP. The threads may be covered individually by biocompatible material such as PTFE or dacron to fill in the gaps between the threads, e.g. in the way shown in FIG. 26 with threads 28 and biocompatible material 29 .
[0136] The patch in FIG. 19 further comprises a frame 17 for anchoring the patch in the body, e.g. by means of sutures. The frame may be made of any biocompatible material, such as PTFE or dacron. By the use of a cone (not shown), the threads may be spread apart, creating a central opening 16 a in the patch. The cone is advanced until a delay means 18 in the form of a separate ring 18 of a resorbable material, initially positioned on the cone, is positioned in the opening 16 a . The cone is then drawn back and the ring 18 is left in the opening 16 a , restraining the elastic threads in such a way that the central opening 16 a in the patch is maintained. FIG. 19 shows the patch in its non-activated state of shape I with the ring 18 positioned centrally. After implant and sufficient resorption of the restraining ring 18 and after a specified period of time, the central opening in the patch is closed and the patch is activated.
[0137] FIG. 20 shows an alternative embodiment of a device according to the invention in the form of a patch for closing openings. The patch may be constructed by attaching delay means 19 in the form of resorbable threads or bands 19 to the top of a sharp cone and down along the sides of the cone, advancing the cone through the middle of the patch so that the elastic threads 16 are spread out and thus an opening 16 a in the patch is created, and fastening one end of each band to the frame 17 on one side of the patch and the other end of each band 19 to the frame 17 on the other side of the patch, so that each band 19 encircles the opening. The bands 19 could be placed at regular intervals along the circumference of the opening so that they expand a substantially circular hole in the middle of the patch. By means of the resorbable bands 19 , the patch is held in its non-activated state of shape J.
[0138] It is to be noted that the above-described different embodiments are examples only. There are many possible different forms of a device according to the present invention. For example, the single shape-changing thread in FIGS. 1 to 9 may be replaced by several threads or by one or more bands. The scissors-shaped members 7 and 9 in FIGS. 10 to 13 may be multiplied so as to form a scissor-shaped area, which in turn may be shaped into different forms. The single tube in FIGS. 3, 7 , 10 and 14 may be slotted or may be divided into several tube segments. A delay means may also be provided in the form of resorbable glue, which holds parts of the shape-changing member together and in that way delay the change of shape of the device. The number of possible designs of a device according to the invention is, in fact, infinitely great.
[0139] Next, an embodiment according to the invention of a device for treatment of mitral annulus dilatation will be described.
[0140] The device shown in FIG. 21 , being in an elongate and non-activated state of shape K, comprises a shapechanging member 20 in the form of a shape memory metal thread 20 , a delay means 21 in the form of a resorbable sheath 21 enclosing the shape memory metal thread 20 for holding it in a straightened state of shape, and preferably self-expandable stents 22 and 23 located at the opposite ends of the device.
[0141] The device may include one or more additional shape memory metal threads, e.g. if a stronger shortening force is desired.
[0142] The shape memory metal thread 20 may be made of Nitinol, or other similar material which has a memory of an original shape as illustrated in FIG. 22 , and can be temporarily forced into another shape, e.g. as illustrated in FIG. 21 .
[0143] The resorbable sheath 21 is made of PDS, but it may also be made of any other material which is resorbable by the surrounding blood and tissue when applied in a human body and has the required stability and bending properties. The thickness of the resorbable sheath 21 is chosen so that the time needed for the surrounding blood and tissue in the coronary sinus 24 to resorb the resorbable sheath 21 enough for the device to enter its second shorter state of shape K′ is adapted to the time needed for the ends of the device to be fixed within the coronary sinus 24 .
[0144] The self-expandable stents 22 and 23 may be of conventional type with an elastic cylindrical unit, made of e.g. Nitinol, in an opened zigzag configuration. FIG. 21 a shows an alternative embodiment according to the invention of a device for treatment of mitral annulus dilatation. Here, the shape memory metal thread 20 is replaced by a scissors-shaped shape-changing member 20 a . The resorbable sheath 21 may then be replaced by resorbable threads 21 a , like in FIG. 10 a . Preferably, self-expandable stents 22 a and 23 a are located at the opposite ends of the device. The state of shape corresponding to K′ in FIG. 22 of the device shown in FIG. 21 a is shown in FIG. 22 a.
[0145] The above-described device as seen in FIG. 21 (or the device as seen in FIG. 21 a ), is positioned in the coronary sinus 24 , shown in FIGS. 23 to 25 , in the following way:
[0146] An introduction sheath (not shown) of synthetic material may be used to get access to the venous system. Having reached the venous system, a long guiding metal wire (not shown) is advanced through the introduction sheath and via the venous system to the coronary sinus 24 . This guiding wire and/or a delivery catheter is provided with X-ray distance markers so that the position of the device in the coronary sinus 24 may be monitored.
[0147] The elongate device in FIG. 21 (or the one in FIG. 21 a ) is locked onto a stent insertion device (not shown) so that the self-expandable stents 22 and 23 (or 22 a and 23 a ) are held in a crimped, non-expanded state. Thereafter, the stent insertion device with the elongate device locked thereon is pushed through the introduction sheath and the venous system to the coronary sinus 24 riding on the guiding wire. After having obtained an exact positioning of the elongate device in the coronary sinus 24 , as illustrated in FIG. 23 where the mitral valve annulus 25 and the mitral valve 26 having a central gap 27 are shown, the stent insertion device is removed. This will release the self-expandable stents 22 and 23 (or 22 a and 23 a ) so that they expand and contact the inner wall of the coronary sinus 24 and thereby provide for a temporary fixation of the elongate device in the coronary sinus 24 . Then, the guiding wire and the introduction sheath are removed.
[0148] After the insertion, the self-expandable stents 22 and 23 (or 22 a and 23 a ) will grow into the wall of the coronary sinus 24 while at the same time the resorbable sheath 21 (or restraining threads 21 a ) will be resorbed by the surrounding blood and tissue in the coronary sinus 24 , as schematically illustrated in FIG. 24 . When the resorbable sheath 21 (or resorbable threads 21 a ) has been resorbed to such a degree that it cannot hold the shape memory metal thread 20 (or the scissors-shaped member 20 a ) in its straightened state of shape any longer, the self-expandable stents 22 and 23 (or 22 a and 23 a ) will be properly fixed into the wall of the coronary sinus 24 as a result of the normal healing process which always occurs after positioning a stent in a blood vessel. Then the shape memory metal thread 20 (or the scissors-shaped member 20 a ) retracts and the device is transformed to its activated shorter state of shape K′, as illustrated in FIGS. 22 and 25 (corresponding to FIG. 22 a ). This shortening of the device makes it bend towards the mitral valve annulus 25 , moving the posterior part thereof forward. This movement reduces the circumference of the mitral valve annulus 25 and thereby closes the central gap 27 .
[0149] The device may be positioned by catheter technique or by any other adequate technique. It may be heparin-coated so as to avoid thrombosis in the coronary sinus 24 , thus reducing the need for aspirin, ticlopedine or anticoagulant therapy. At least parts of the device may contain or be covered with drugs like Tacrolimus, Rappamycin or Taxiferol to be delivered into the tissue to prohibit excessive reaction from surrounding tissue. At least parts of the device may be covered with or contain VEGF (Vascular Endothelial Growth Factor) to ensure smooth coverage with endothelial cells.
[0150] FIG. 26 shows one possible arrangement of a part of a contractable area according to the invention. The contractable area comprises a shape-changing member in the form of a grid matrix of shape memory metal threads 28 covered by a delay means in the form of a fabric of a resorbable material (it should be noted that FIG. 26 was previously used to illustrate how the threads of the patches of FIGS. 19 and 20 may be covered with biocompatible material). The fabric comprises resorbable bands 29 which have been weaved together to form an area. Each of the resorbable bands 29 is solid except for a cylindrical hollow space in which a thread 28 is located, just like the thread 1 is located inside the tube 2 in FIG. 3 .
[0151] The bands 29 restrain the threads 28 from being folded to their original curved shapes as long as the fabric 29 is not resorbed.
[0152] Analogously to the device in FIG. 3 , there may be a radial play between the inner wall of each band 29 and the thread 28 being located inside it, in which play the thread 28 can move without consequently being able to change the size of the area of the device to any larger extent.
[0153] Further, the hollow space in each band 29 must not necessarily be cylindrical. In fact, if the width of each band 29 is small enough as compared to the curves that the threads 28 will assume when being “activated” as a result of the bands 29 being resorbed, the bands 29 may be hollow.
[0154] The contractable area in FIG. 26 may be manufactured by threading a thread 28 of a memory material into each resorbable band 29 and then weaving the bands 29 with threads 28 together to form the fabric as illustrated in FIG. 26 .
[0155] Another possible way of making a contractable area according to the invention would be to arrange threads or bands of a memory material in a grid matrix and to fix the threads or bands together with resorbable crosslinks. The resorbable crosslinks would then restrain the threads or bands from being folded as long as enough resorbable material in the crosslinks is left unresorbed.
[0156] A contractable area according to the invention, as the one previously mentioned or as the one shown in FIG. 26 , may be formed into a contractable sac as shown in FIGS. 27 to 30 , which sac may be used to support a body organ or to restrain a pathologically growing body organ.
[0157] FIGS. 27 to 30 illustrate the use of a contractable sac 30 for treatment of pathological heart growth, according to another embodiment of the invention.
[0158] Referring to FIG. 27 , the sac 30 in its non-activated state of shape L is threaded inside out on a catheter 31 with an anchoring means 32 , here in the form of a suction cup 32 , and the catheter 31 with the sac 30 is introduced to the apex cordis 33 a of the heart 33 in known manner.
[0159] Now referring to FIG. 28 , the suction cup 32 is put on the apex cordis 33 a and the sac 30 is pushed off the catheter 31 , by means of a catheter instrument (not shown), over the suction cup 32 and up over the heart 33 .
[0160] Now referring to FIG. 29 , when the sac 30 is positioned round the heart 33 , the suction cup 32 is pulled out through the bottom of the sac 30 and the catheter 31 is removed from the body.
[0161] After a period of time, the resorbable material of the sac 30 will be resorbed and a restraining force by the shape memory metal threads against the heart 33 is released, and hence, the sac 30 is transformed to its activated state of shape L′, as illustrated in FIG. 30 . The sac 30 will then press itself tight round the heart 33 and apply a continuous restraining force on the heart 33 , thus decreasing the heart size, or at least preventing the heart 33 from growing further.
[0162] A contractable area according to the invention can also be used as a contractable sheet for treatment of alveolar sac growth, e.g. in emphysematic pulmonary diseases.
[0163] FIGS. 31 and 32 show the use of an embodiment of a device according to the invention for treatment of alveolar sac growth.
[0164] Referring to FIG. 31 a contractable sheet 34 in its non-activated state of shape M is rolled up on a catheter 35 , introduced between ribs 36 into the pleural cavity (the space between the pleura of the lung and the pleura of the chest wall), and placed upon the lung 38 surface to be treated.
[0165] The contractable sheet 34 may also be inserted into the body by means of open surgery or by means of endoscopic surgery and positioned on an organ surface.
[0166] Now referring to FIG. 32 , the sheet 34 is then rolled out over the lung 38 and the catheter 35 is removed.
[0167] The sheet 34 is arranged to grow fixed to the lung surface so that subsequent contraction of the sheet 34 , as a result of the resorbable material of the sheet 34 being resorbed, causes the sheet 34 to compress the lung 38 by means of a force of the shape memory metal threads in the sheet 34 . Hence, bullae and areas of enlarged alveolar sacs may be shrunk or eliminated and further pathological growth of alveolar sacs may be prevented.
[0168] In this embodiment the contractable sheet 34 contracts in two directions, one approximately vertical and one approximately horizontal. The sheet 34 could also be designed to contract in one direction only, e.g. the most horizontal one, or contract in a circular mode, and still be able to shrink bullous areas and prevent alveolar sacs from growing.
[0169] It is to be understood that modifications of the above described devices and methods can be made by people skilled in the art without departing from the spirit and scope of the invention.
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A delivery system for delivering a prosthetic heart valve to a native valve site within the human vasculature. The prosthetic valve is disposed on a balloon at the end of a balloon catheter. The balloon catheter passes through a delivery sleeve assembly and handle. A pull wire travels from the handle to a distal end of the delivery sleeve assembly. Actuation of the handle pulls on the pull wire, which causes openings in a slotted tube of the delivery sleeve assembly to close, thus causing the delivery sleeve assembly to bend. A stretchable cover is placed over the slotted tube for biasing the steerable catheter toward a straight position. Once advanced to the native valve site, the prosthetic valve is deployed by inflating the balloon.
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TECHNICAL FIELD
This invention, in art of construction, particularly relates to a steel structural system, which integrally combines steel frame with foaming cement, by embedding the former in the latter, to afford a structural system that resists fire, insulates heat, carries load and beautifies the environment.
BACKGROUND TECHNOLOGY
To date, steel structures are ready to erect and resistant to earthquake, with many merits for procedural, diversifying or industrialized production. However, the fender structures used in cooperation therewith are mostly made of such building materials as rolled steel sheets, gypsum rock wools or glass wool, so that the building structures formed thereby, especially in residential buildings, are poor in fire resistance, vulnerable to thermal bridge and costly in overall construction. Moreover, houses of the kind cannot render a comfortable feeling.
SUMMARY OF THE INVENTION
This invention is to provide a new type of foaming cement material, which integrally cooperates with steel frame to form a fender structure capable of bearing load in vertical or horizontal direction, either by the fender itself or by its combination with other building members through the lightweight steel frame being embedded in the foaming cement or between foaming cement boards/slabs. The fender structure, in cooperation with roof boards, ceilings and all types of floor slabs, forms a structural system that is capable of insulating heat, bearing load and beautifying the environment, comprising the followings:
This invention provides an A-type fender structure which, capable of carrying load solely by itself or by its combination with the main structural steel, possess the merits of fire resistance, load bearing, waterproof, heat insulation, beautiful decoration and ready erection. It a kind of load-bearing structure with a shaped steel frame embedded in the foaming cement.
This invention provides a B-type fender structure which, capable of carrying load solely by itself or by its combination with the main structural steel, possess the sound merits of fire resistance, load bearing, waterproof, heat insulation, beautiful decoration and ready erection. It's made up of a load-bearing B1-type board formed by steel frame partially embedded in the foaming cement with its mating part B2-type of foaming cement without the framework.
This invention provides C-type boards as well as a C-type fender structure where the steel frame is sandwiched between the said two C-type boards. It is entailed not only the effectiveness of fire-resistance and durability, but also the merit of load bearing, heat insulation, sound absorption and environment beautification as well.
This invention provides an assembled lightweight partition wallboard which, capable of being assembled or disassembled freely on site, is tied together with roof boards and floor slab by screws.
This invention also provides a process for constructing buildings of different shape, which uses foaming cement as the basic material for fire resistance, heat insulation and decorative designs. Together with various steel frames and cement surface layers, it can offer a series of ready-in-use buildings of light weight and rich patterns, with good performance in strength, durability, fire resistance and thermal insulation.
Still another purpose of this invention is to provide a new method for house construction using lightweight steel structures and a variety of lightweight boards to add floors to old buildings or to reconstruct old residential houses into completely renewal ones with all facilitates thereof upgraded at the same time.
The technical solutions of this invention comprises:
A type of structural system formed of foaming cement and lightweight steel structure (steel frame), which is further divided into mid-low-rise and mid-high-rise building structural systems, wherein the former is made up of A, B, or C-type fender structure, floor slabs, decorative elements, ceilings and assembled partition wallboards, and the latter A, B, or C-type fender structure, steel columns, floor slabs, decorative elements, assembled partition wallboards and ceilings; said foaming cement used therein has a density of 150 kg/m 3 −400 kg/m 3 and a thermal conductivity of 0.035-0.08 w/mk. It dose not need high-temperature steam curing, and is water impermeable (i.e. when dropping water on the surface of the foaming cement, water drop cannot penetrate through capillary into the foaming cement), and has airtight-cavity cellular structure (i.e. each cavity is separated from the others by walls thereof and thus every of them is isolated).
Of the fender structures, said A-type fender structure can either be formed on site with foaming cement or be assembled with pre-cast A-type board provided by manufacturers; said B-type fender structure is assembled on site with B1 and B2-type boards; and said C-type fender structure is formed of C1 and C2-type boards with steel frame sandwiched between them.
Said A, B, or C-type fender structure may be fastened mechanically to the steel skeleton of a building with steel frame embedded in the foaming cement. A, B, or C-type fender structure can be applied for walls and roofs.
Said foaming cement is made of dicalcium silicate, anhydrous calcium sulphoaluminate and sulphate dihydrate as main ingredients for gelatinizing, or by adding a given quantity of tricalcium silicate to form a compound, to mix with foaming agents and others modifying additives.
Said foaming cement may be added with an appropriate amount of fiber or organic resin to increase its tenacity. Said high-polymer fiber may be glass fiber, carbon fiber or dietary fiber.
Said foaming cement may be formed of the type of cement, whose density exceeds 400 kg/m 3 and whose thermal conductivity 0.8 w/mk, or by any other types of cements mixed with foaming gypsum, lightweight thermal insulation materials and gelatinizing materials.
The composition and content of said foaming cement are 10-70% dicalcium silicate, 10-70% anhydrous calcium sulphoaluminate, 10-70% sulphate dihydrate, 0-90% tricalcium silicate and 10-50% water, with thereto 1-10% foaming agent and 1-10% modifying additive mixtures.
Said surface layer of the foaming cement may be of elastic materials if without embedded reinforcing steel. Such surface layer can be made up of resin cement or elastic coating materials, etc.
Said surface layer of the foaming cement may be made into different patterns and shapes, such as brick face, stone carving, tiled shape, decorative line-arts or other ornamental designs.
Said surface layer of the foaming cement can be made into different colors or be coated with other colored finishing materials. For example, color cement can be coated on the surface layer, various surface paints can be brushed on it and decorative materials in wood grain pattern or those made from aluminum sheet, aluminum-plastic material, glass fiber reinforced plastics, stove tiles, other metals or plastic materials, can also become the panels therefor.
Said joint channels are lap joints (wedged or dovetailed) and the shape of which may be corrugated. Said joint channels can be socket or butt joint.
In the gap between connected joint channels, air-tight materials such as fluid sealants and foaming polyurethane may be filled in to make it waterproof.
Said reinforcement ribs are steel girders or small-sized shaped steels or small-sized shaped steels with slots.
Said tension-resistant materials can be wire meshes, fibers, fiber lattice, dietary fibers or organic resins, etc.
Said steel reinforcements are formed of steel reinforcement bars surrounded by a given thickness of cement, and the steel reinforcement bars are connected to the said reinforcement ribs or to other anchored steel reinforcement members in the foaming cement.
Said reinforcement bars are placed between the tension-resistant surface materials and foaming cement entity under the surface layer, whereby not only bonding strength of foaming cement is increased but also the steel reinforcement bars are well protected by a given thickness of cement cover.
Said reinforcement ribs can be made up of frame materials other than steel girders or small-sized shaped steels.
Said shaped steel of the steel frame can be of tendons of smaller shaped girders or their combinations.
Said steel frame or girders may also refer to wood frames, girders or their combinations.
Said embedded expansion joints may be placed anywhere around or at the center of the cement board to fasten cement board either by bolting or riveting to the steel frame. Through fixation holes, set bolts fix the embedded expansion joints to the steel frame. Fixation holes can be changed on site accordingly. When used as exterior walls, proper joints channels assure the watertight connection in addition to the fluid sealant and site-foamed polyurethane applied thereto.
Said steel column may be formed of steels of various sections, like H-shape steel, square or round steel tube etc., or of steel core concrete column or , , -shaped steel concrete column.
An A-type fender structure is formed by several A-type boards which are mechanically tied with one another by expansion joints or mechanically tied to the building steel skeleton. The expansion joints are at the ends of shaped steel frame and protrude out of the surface of the board.
Said A-type board is a board in which reinforcement ribs are embedded in foaming cement; cement surface layer strengthened with tension-resistant material is coated on the surface; steel reinforcements are placed in the binding area between foaming cement and cement surface layer; shaped steel frame mechanically tied with reinforcement rib is embedded in foaming cement; expansion joints of shaped steel frame protrude out of the surface of the board; and joint channels are made along the border of the board.
Said A-type board may be shaped into curved, angled or channeled designs.
Said A-type fender structure can be foamed on site. It begins from steel frame construction. After framework is well done, the cement surface layers can be prepared for decoration purpose. Besides this, other panels made of different materials, for example, metal, glass fiber reinforced plastics, wood or high-polymers, can be used instead for exterior and interior decoration. Then, these exterior and interior panels are mechanically fastened to the steel frame and the reinforcement ribs via joint members through thermal bridge. Next, cement foaming fluid is poured into the empty space, enclosed by exterior, interior boards, and steel frame, and begins to foam. Finally the whole wall is completed. Now, the exterior and interior boards may be partially connected with the reinforcement ribs, and the binding areas between surface layer and foaming cement entity can act as anchored concrete reinforcement in the foaming cement. When used for roofs, the exterior boards can be replaced with sheathings, tiled board or flexible waterproof material (See the Inventor's Application for Chinese Patent Invention No. 99109346. I, which is incorporated herewith by reference in its entirety.).
With regard to A-type fender structure, it is possible to break it up into several parts according to drawings, in such a size as required by transportation, so that the steel frame, foaming cement, reinforcement ribs, tension-resistant materials, reinforcing steel and cement surface layer can be pre-cast in the factory. Windows may also be opened in the wall in factory, and all the individual parts can be assembled on site by bolting or welding. When connected by bolts, joint members can be embedded into the floor slab because it will be poured later on site; When welded, the columns may be split into two pieces of shaped steels and be welded together on site. (see the Inventor's Application for Chinese Patent for Invention No. 0010 0543. X, which is incorporated herewith by reference in its entirety).
A B-type fender structure is formed by B1 board and its mating part B2 with foaming cement, steel reinforcements and reinforcement ribs inside the boards; On the outer surface layer of B1 or B2 is the cement surface layer strengthened by tension-resistant materials; Inside the foaming cement of B1 board is embedded shaped steel frame mechanically tied to reinforcement ribs with the framework partially exposed. Upon the exposed part are many expansion joints. Inside B2 board are embedded expansion joints with fixation holes. There are joint channels around both B1 and B2 boards; and the embedded expansion joints in B2 board are mechanically fixed to the steel frame inside B1 board.
A B-type fender structure, wherein it is formed of B1 board and its mating part B2 board. Inside the board are foaming cement, steel reinforcement and reinforcement ribs; on outer surface of B1 or B2 board is cement surface layer strengthened by tension-resistant material; inside foaming cement of B1 board is embedded shaped steel frame mechanically tied to reinforcement ribs with the steel frame partially exposed. Upon exposed part of the steel frame are expansion joints; Inside B2 board are embedded expansion joints with fixation holes; there are joint channels around the border of B1 or B2 boards; and the embedded steel expansion joints in B2 board are mechanically tied to steel frame inside B1 board.
Said B1-type board is the one in which reinforcement ribs are embedded in the foaming cement and a cement surface layer strengthened with tension-resistant material is coated only on one side of the board. In binding area between foaming cement and surface layer are the steel reinforcements. Inside the forming cement is embedded shaped steel frame mechanically tied to the reinforcement ribs with the steel frame partially exposed; outside the board are expansion joints and around the board are joint channels.
Said B2-type board is the one in which reinforced ribs are embedded in the foaming cement and a cement surface layer strengthened by tension-resistant materials is coated on one side of board. In binding area between foaming cement and surface layer are steel reinforcements; On the other side of the board are embedded expansion joints with fixation holes, and around the board are joint channels.
Said B1 and B2 boards may be shaped into curved, angled or channeled designs.
Said B2 board may be formed of other type of boards made with foaming cement, for example, gypsum, when used for exterior walls.
Said B-type fender structure, if used as roof, may be converted into tiled shape with steel frame exposed, and B2 board may not be used.
Said B-type fender structure may be broken up into several parts suitable for transportation. The work can be carried out in a line with the internal structure of the board without any sacrifice on its load-bearing capacity. Both B1 and B2 boards can be factory made. On construction site, the partially exposed steel frame inside B1 board is connected to one another with either bolts or rivets, and can be connected to B2 board via the embedded expansion joints inside B2. The built-in works, e.g. various pipes and wires, can be embedded between B1 and B2 boards. When used as exterior wallboard, it can be made waterproof with sealant filling the joint gap of tap, socket or butt joint channels. Steel expansion joints on exposed B1
steel frame are easy for use because they can be set wherever needed.
The B-type fender structure of this invention is a structure of large lightweight board and wallboard which are connected by welds and bolts. It is particularly suitable for dwelling houses as exterior walls, partition walls or roof boards and is getting popular for industrial use as exterior, fire-resistance and partition wallboards. (See the Inventor's Chinese Patent Application No. 00100542.1, which is incorporated herewith by reference in its entirety)
A C-type fender structure is formed by two cooperating C1 and C2 boards with foaming cement, reinforcing steel and reinforcement ribs inside. On the outer surface of C1 or C2 is the cement surface layer strengthened by tension-resistant materials; Between C1 and C2 boards is the shaped steel frame; Inside the board are embedded expansion joints with fixation holes and around the board are the joint channels.
Said C-type board is the board in which reinforcement ribs are embedded in foaming cement, a cement surface layer strengthened with tension-resistant materials is coated outside on one side of the board, while on the other side are the embedded expansion joints; steel reinforcements are placed between surface layer and foaming cement. Around the board are the joint channels.
When said C-type fender structure is used as roof boards, the cement surface layer of said C1 board can be made into tiled shape, the steel frame may still be exposed but the C2 board may not be used.
When said C-type fender structure is used as roof boards, said C1 board may be formed of rolled metal sheets, cement tiles, etc. to make it waterproof, while C2 board can be the heat insulation and fire resistant ceiling.
Said C1 and C2 board may be made into curved, angled or channeled designs.
When C-type fender structure is used as exterior walls, C1 board may be equipped with an air barrier on its inner side to make the exterior wall damp-proof in cold regions.
Said C2 board may be formed with materials other than foaming cement, for example, the gypsum when used as exterior wall.
Said members of steel frame in C-type fender structure should be made in factory and installed on site. The various building loads will be carried by steel frame. On construction site, the steel frame is first assembled and then are the C1 and/or C2 boards. Depending on the load, different bolts and rivets may be chosen. The two boards are clinched to the steel frame via embedded steel expansion Joints with fixation holes of C1and C2 board. After fixation, fixation holes can be filled with special material, which is a mixture of cement and lightweight heat insulation material. This mixture can be that of cement and pearlite or that of cement and polystyrene. Moreover, various pipes and wires can be laid in between C1 and C2 boards.
This invention also provides a special column structure which, formed of profiled steel concrete or shaped steel girders, is as thick as the walls of building. It can be in , , and -shape and can substitute for the steel column.
On occasion in which the diameter of shaped steel column is wider than the thickness of wall, special fireproof boards—C3-type—may be applied for the purposes of decoration. Other decorative materials may also do. (See the Inventor's Application for Chinese Patent No. 0010 0541.3, which is incorporated herewith by reference in its entirety)
Said various load-bearing fender structures may be used together and form a variety of building structures in cooperation with shaped steel columns, floor slabs, decorative members, ceilings and partition wallboards.
The shaped steel columns may be of the composite , and shaped columns.
The shaped steel columns may cooperate with A, B or C girder fender structure to support floor slabs at top and bottom ends thereof. If placed in a staggered fashion between floors, they may form a bay of double span. The floor slabs made from girders and ceilings can form a fire-resistance, lightweight, large-span bay over load-carrying walls. The girders thereof may be made of steel or wood. Said floor slabs, as lightweight fireproof building members, may be molded on site with reinforcement members, or be cast with steel or wood moulds, or be poured with pre-stressed lap boards, or be formed by foaming cement ceiling with girders.
Said ceiling may be made of C-type board.
This invention provides an assembled partition wallboard with reinforcement ribs embedded in the foaming cement, cement surface layer strengthened with tension-resistant materials, steel reinforcement placed at the place of binding area between surface layer and the foaming cement. There are joint channels along both sides of the board with bolt fixation on top and bottom side of the board. The set bolts are connected to the reinforcement ribs. On corresponding places of roof boards and floor slabs there are holes or joint channels for the bolt fixation.
For large-spanned buildings, assembled partition wallboards may be used so that the room space may be arranged in different ways to meet actual needs. (See the Inventor's Application for Chinese Patent No. 0010 0544.8, which is incorporated herewith by reference in its entirety)
This invention also provides a process for forming fire resistance structures of many shapes, whereby the easiness of forming and processing of foaming cement in moulds is made use of. It can be used for exterior and interior decoration or for landscape, and comprises the following steps:
Step One: Reinforcement ribs and small embedded expansion joints are first cast on site with foaming cement;
Step Two: Surface of the foaming cement is processed into desired shapes for decoration, and the reinforcement ribs embedded in the cement are partially exposed out of the foaming cement surface in a way that is used as steel reinforcements later.
Step Three: Spraying or brushing tension-resistant materials on the surface of foaming cement to form surface layer.
This method, whereby the foaming cement is made at first and then its surface is shaped into different designs when cement is set. Steel reinforcement bars embedded in foaming cement are partially exposed, so that they can form steel reinforcements with surface layer cement when it is sprayed or brushed on the foaming cement entity. With this method it's easy not only to accomplish many decorative designs but also to enhance the bonding strength between surface layer and foaming cement through the steel reinforcements.
This method can produce A, B or C-type boards, panels or joint channels in many decorative shapes, and, when applied to roofing, can produce corrugated or tiled decorative designs for roof drain system.
Said decorative structure is formed of airtight-cavity foaming cement with decorative surface layer. The shape of decorative design is set by steel frame inside while reinforcement ribs are mechanically tied to the steel frame and connected with steel reinforcement, which is placed in binding area between foaming cement and the decorative surface layer. In the said foaming cement may be embedded expansion joints with fixation holes.
Said architectural decorative pattern may be used for fascia, column head, lintel, column contour, handrail as well as a variety of inner and outside objects, such as rockery, garden sculpture, scenery landscape etc. (See the Inventor's Chinese Invention Patent No. 00100545.6, which is incorporated herewith by reference in its entirety)
This invention provides a process for old building renovation with steel structures, whereby the foundation of existing heavyweight structure can be reused. This Inventor's A, B or C-type truss fender structures can be used as partition walls and A, B or C-type fender structures as exterior walls. The assembled partition boards are used for interior partition walls. In cooperating with steel columns, floor slabs, decorative structures and ceiling, the steel columns and steel structure of the old building are firmly held together. A lightweight structure is constructed on the top of the building. Where the technical condition permits, the foundation is reformed to accommodate the newly lightweight building structures. Then, with many cooperating floor slabs cast on site, the steel columns are somehow safely connected to the existing building with a temporarily set supports and cables to stabilize the entire building. Possible storeys of the new building depend on the condition of the foundation, and the construction work can be carried on from the top of old building. With the new building going up, the old building is demolished and renovated from top down. The demolition and renovation should be carried out within the load-bearing capacity of the foundation and continued until the entire old building is pulled down, and then anther reconstruction work could be done for the foundation. With this technology, the renovation project is easily executed by pulling down old buildings to construct new ones on the foundation of the former.
For this invention another patented invention of the inventor is used, namely “the technology of installing guyed structure on steel columns of the structure skeleton of a main steel structure in the process for constructing dwelling houses ” (the Inventor's Patent Application No. 99109102. 7, which is incorporated herewith by reference in its entirety), so as to ensure the stability in the process of construction. This is a technology whereby a steel boot structure is set under steel columns of main building steel structure. Because it distributes pressure in a larger area of the ground, building construction can be stabilized under vertical load. Using this technology would make it possible to construct a platform on top of any existing one-storied or multiple-storied buildings, so that normal human life is kept intact therein, while upper parts is being constructed on the platform. After the upper parts of the house are made available for use, residents from lower floors may move up and the lower parts are demolished, and the foundation reconstruction work begins.
Said guyed structure may be realized by effectively connecting two steel structures of adjacent individual buildings of steel structure. Since the steel connecting members of each building are pre-designed and connected to main building structure, this building's joint members can couple with those of others to make adjacent buildings into one unit. Turning the individual buildings into a part of the whole structure of a building group not only makes the latter well established but also ensures the stability of the former. In this invention, newly renovated buildings may be laterally connected to a building group to attain stability and diversified utilization, for example, suspended gardens, shopping malls and sports centers, etc.
With a process of this invention to build steel structures for renovation of old buildings, steel connecting structures may be used to connect adjacent steel structures in order to turn a separate building into a part of whole buildings, which stabilizes not only the grouped buildings but also individual ones, so that the newly built higher buildings standing on the foundation of existing old ones are laterally stable. The connected steel structure may be formed of A, B or C-type fender structure, so that it becomes suspended. Ropes or cables may be used for temporary fixation during the construction. The connecting structure may vary in shape as corridors, arched bridges or a H-shaped structures. Said connecting structure may connect several individual buildings to form building clusters.
To ensure the lateral stability of the higher building newly erected on the foundation of the existing building, the connecting steel structure may be used to connect adjacent buildings to turn an individual building into a building cluster in order to stabilize both the cluster and the individual buildings. The connecting steel structure may be formed of A, B or C-type fender structure to make it a suspended building. Ropes or cables may be used for temporary fixation during construction. (See the Inventor's Application for Chinese Invention Patent No. 00100693.2, which is incorporated herewith be reference in its entirety.)
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIG. 1 is the schematic diagram of the structure of this invention.
FIG. 2-1 is the schematic diagram of A-type fender structure of this invention.
FIG. 2 - 2 - 1 is the schematic diagram of A-type board with lap joint of this invention.
FIG. 2 - 2 - 2 is the schematic diagram of A-type board with socket joint of this invention.
FIG. 2 - 2 - 3 is the schematic diagram of A-type board with butt joint of this invention.
FIG. 2-3 is the schematic diagram of blanket columned A-type fender structure of this invention.
FIG. 2-4 is the schematic diagram of A-type truss fender structure of this invention.
FIG. 3-1 is the schematic diagram of B-type fender structure of this invention.
FIG. 3 - 2 - 1 is the schematic diagram of B1-type board with lap joint of this invention.
FIG. 3 - 2 - 2 is the schematic diagram of B1-type board with socket joint of this invention.
FIG. 3 - 2 - 3 is the schematic diagram of B1-type deck with butt joint of this invention.
FIG. 3 - 3 - 1 is the schematic diagram of B2-type board with lap joint of this invention.
FIG. 3 - 3 - 2 is the schematic diagram of B2-type board with socket joint of this invention.
FIG. 3 - 3 - 3 is the schematic diagram of B2-type board with butt joint of this invention.
FIG. 3-4 is the schematic diagram of Application 1 with blanket columned B-type fender structure of this invention.
FIG. 3-5 is the schematic diagram of Application 2 of B-type truss fender structure of this invention.
FIG. 4-1 is the schematic diagram of C-type fender structure of this invention.
FIG. 4 - 2 - 1 is the schematic diagram of C-type board with lap joint of this invention.
FIG. 4 - 2 - 2 is the schematic diagram of C-type board with socket joint of this invention.
FIG. 4 - 2 - 3 is the schematic diagram of C-type board with butt joint of this invention.
FIG. 4-3 is the schematic diagram of Application 1 of blanket columned C-type fender structure of this invention.
FIG. 4-4 is the schematic diagram of Application 2 of C-type composite column fender structure of this invention.
FIG. 4-5 is the schematic diagram of Application 3 of C-type truss fender structure of this invention.
FIG. 4-6 is the schematic diagram of Application 4 of the profiled C-type fender structure of this invention.
FIG. 5 is the schematic diagram of assembled partition wall of this invention.
FIG. 6-1 is the schematic diagram of Application 1 of decorative pattern of this invention.
FIG. 6-2 is the schematic diagram of Application 2 of the decorative pattern of this invention
FIG. 7 is the schematic diagram of steel structure for building renovation method of this invention.
DESCRIPTION OF EMBODIMENTS
This invention is further explained by way of examples with reference to the accompanying drawings of the description.
The structural system of this invention as shown in FIG. 1 :
This invention mainly comprises load-bearing fender structure ( 111 ), shaped steel columniation ( 222 ), floor slabs ( 333 ), decorative design ( 444 ), ceiling( 555 ) and assembled partition wall( 666 ), wherein the load-bearing fender structure ( 111 ) is formed of A-type fender structure, B-type fender structure or C-type fender structure. Of them said A-type fender structure, in turn, is formed of several A-type boards; said B-type fender structure is formed of two mating B1 and B2 boards; and said C-type fender structure is formed of two mating C1 and C2 boards.
As is shown in FIG. 2 - 1 : A-type fender structure of this invention is the structure in which reinforcement ribs ( 6 ) are embedded in the foaming cement ( 1 ); the cement surface layer ( 4 ) strengthened by tension-resistant material ( 3 ) is coated outside; steel reinforcement ( 2 ) is set between foaming cement entity ( 1 ) and cement surface layer ( 4 ); shaped steel frame ( 5 ) is tied with reinforcement rib ( 6 ) in the foaming cement ( 1 ); expansion joint ( 7 ) of the steel frame ( 5 ) protrudes outside the surface of the board; and joint channel ( 9 ) edges the border.
Moreover, fluid sealant may be applied to joint gap between two joint channels ( 9 ) to make it waterproof.
As FIG. 2 - 2 - 1 shows: A-type board with lap joint of this invention is the one in which reinforcement ribs ( 6 ) are embedded in the foaming cement ( 1 ); cement surface layer ( 4 ) strengthened by tension-resistant material ( 3 ) is coated outside; steel reinforcement ( 2 ) is set between foaming cement entity(I)and cement surface layer ( 4 ); shaped steel frame ( 5 ) mechanically tied with reinforcement ribs ( 6 ) is embedded in the foaming cement ( 1 ); expansion joint ( 7 ) of the steel frame ( 5 ) protrudes outside the surface of the board and the lap joint channels ( 9 ) edges the border. When the board is used as roofing, cement surface may be corrugated and the lap joint channels ( 91 ) be corrugated.
As FIG. 2 - 2 - 2 shows, socket joint A-type board is different from lap A-type board in that socket joint channel ( 92 ) is along the border instead.
As FIG. 2 - 2 - 3 shows, butt joint A-type board is different from lap A-type board in that butt joint channel ( 93 ) is along the border instead.
There are two best examples of A-type fender structure of this invention:
Example 1: As FIG. 2-3 shows, blanket columned A-type fender structure is formed by A1, A2, A3 or A4 boards, and inside them is the steel frame composed of beams ( 51 ), columns ( 52 ), braces ( 53 ), beam expansion joints ( 511 ) and column expansion joints ( 521 ). The columns ( 52 ) may be replaced by vertical girders(?) to become composite columns, which may be placed at the corner of a building, at the place where exterior and interior wall meets or the intersection of partition walls, and at the place as required for load carrying.
Example 2 : As FIG. 2-4 shows, integrated A-type truss fender structure is formed of A1 and A2 boards, in which are placed the steel frame formed of beams ( 51 ), columns ( 52 ), braces ( 53 ). The girders inside A1 and A2 boards are connected into a whole structure using the expansion joints ( 54 ) of the steel frame with which the boards are connected, and are formed into a integrated structure with the columniation ( 222 ) placed on each end thereof. The columniation in the structure may be the various steel columns, steel core concrete columns, special , or -shaped steel core concrete columns and grouped columns of , or -shaped girders. The columns may be placed at the corner of a building, in the place where the outer and inner walls meet, in the place where the inner partition walls crisscross, or any place as required for carrying the load of the building.
As FIG. 3-1 shows, the B-type fender structure of this invention is formed of B1 and B2 two mating boards. Inside the boards there are foaming cement ( 1 ), steel reinforcement ( 2 ) and reinforcement ribs ( 6 ), and on the outer surface of the boards is the cement layer ( 4 ) strengthened by tension-resistant material ( 3 ), wherein shaped steel frame ( 5 ) mechanically tied with steel reinforcement ( 6 ) is embedded in the foaming cement ( 1 ) of B1 board, with a part of steel frame ( 5 ) exposed and on top of which there are the expansion joints ( 71 ) of the frame ( 5 ); embedded in B2 board are the expansion joints ( 72 ) and the fixation holes ( 8 ); along the outer edge of the B1 and B2 boards are the joint channels ( 9 ); and on the inner surface of B1 board is an isolated layer to facilitate damp-resistance of the outer wall in cold regions. In addition, the fluid sealant may be applied to the gap between connecting joint channels ( 9 )to make it waterproof.
As FIG. 3 - 2 - 1 shows, lap joint B1-type board of this invention is one in which reinforcement ribs ( 6 ) are embedded in the foaming cement ( 1 ); there is a cement surface layer ( 4 ) strengthened by tension-resistant material on one side of the board's outer surface; steel reinforcement ( 2 ) are embedded in binding area between the foaming cement ( 1 ) and cement surface layer ( 4 ); steel frame ( 5 ) mechanically tied with reinforcement ribs ( 6 ) is embedded in the foaming cement ( 1 ), with a part thereof exposed; on it there are expansion joints ( 71 ) for the frame( 5 ); and there are lap joint channels ( 91 ) along the border of the board.
As FIG. 3 - 2 - 2 shows, socket joint B1-type board is different from lap ones in that there are socket joint channels ( 92 ) along the border.
As FIG. 3 - 2 - 3 shows, butt joint B1-type board is different from lap B1-type board in that there are butt joint channels ( 93 ) along the edge.
As FIG. 3 - 3 - 1 shows, B2-type board of this invention is the one where reinforcement ribs ( 6 ) are embedded in the foaming cement ( 1 ), wherein there is the cement surface layer ( 4 ) strengthened by tension-resistant material( 3 ) on one side of its outer surface; there are steel reinforcement ( 3 ) at the bonding place between foaming cement ( 1 ) and cement surface layer ( 4 ); there are embedded the expansion joints ( 72 ) and fixation holes ( 8 ) on the other side; and there are joint channel ( 91 ) around the border.
As FIG. 3 - 3 - 2 shows, socket joint B2-type board is different from lap B2-type board in that there are socket joint channels ( 92 ) around the border instead.
As FIG. 3 - 3 - 3 shows, butt joint B2-type board is different from lap B2-type board in that there are butt joint channels ( 93 ) around the border instead.
There are two best examples of the B-type fender structure of this invention:
Example 1: As FIG. 3-4 shows, blanket columned B-type fender structure is formed of B1 and B2 boards with shaped steel frame composed of beams ( 51 ), girders ( 511 ), columns ( 52 ), braces( 53 ) and expansion joints ( 71 ). The column ( 52 ) in said steel frame may be replaced by girders formed of vertical columns to form composite truss columns of , or -shapes, which may be placed at the corner of a building, at the intersection where exterior and interior walls meet or where the inner partition walls crisscross, or in any places as required for carrying the load. Example 2: As FIG. 3-5 shows, the integrated B-type truss wall structure is formed of the B1 and B2 board with shaped steel frame composed of beams( 51 ), columns ( 52 ), braces ( 53 ) and expansion joints( 71 ). When used in buildings, this wall structure should be equipped with steel columniation ( 222 ) at the two ends of integrated truss. The columniation may be of various shaped steel columns, steel-core concrete columns, special , or -shape steel-core concrete columns and the composite columns of , or -shaped girders. It may be placed at the corner of a building, in places where outer and inner walls meet, or where inner partition walls crisscross, or any other places as required for carrying the load of building.
As FIG. 4-1 shows, C-type fender structure of this invention is formed of C1 and C2 two mating boards. In these boards are foaming cement ( 1 ), steel reinforcement( 2 ) and reinforcement ribs ( 6 ); on their outer surface is the cement surface layer ( 4 ) strengthened with tension-resistant material ( 3 ); in between the C1 and C2 boards are steel frame ( 5 ); inside C1 or C2 boards are embedded expansion joints( 7 ) and fixation holes ( 8 ); along the outer edge of C1 or C2 board are the joint channels( 9 ). On inner surface of said C1board there may be installed with an isolate layer to facilitate damp-resistance of the houses when used as exterior walls in cold regions.
Furthermore, fluid sealant may be applied to the gap where joint channels ( 9 ) are connected so as to make it water proof.
As FIG. 4 - 2 - 1 shows, lap joint C-type board of this invention is the one where reinforcement ribs ( 6 ) are embedded in foaming cement ( 1 ). There is a cement surface layer ( 4 ) strengthened with tension-resistant material ( 3 ) coated on one side of its outer surface and the embedded expansion joints are on the other side. There are fixation holes ( 8 ) on embedded expansion joints, steel reinforcement( 2 ) in the binding area formed by foaming cement ( 1 ) and cement surface layer ( 4 ), and lap joint channels ( 91 ) around the border.
As FIG. 4 - 2 - 2 shows, socket joint C-type board is different from lap C-type board in that there are socket joint channels ( 92 ) around the border instead.
As FIG. 4 - 2 - 3 shows, butt joint C-type board is different from lap C-type board in that there are butt joint channels ( 93 ) around the border instead.
There are four best applications by C-type fender structure of this invention:
Example 1: As FIG. 4-3 shows, blanket columned C-type fender structure is formed of steel frame composed of beams ( 51 ), girders ( 511 ), columns ( 52 ), braces ( 53 ) and laterally arranged C1 and C2 boards.
Example 2: As FIG. 4-4 shows, blanket columned+composite column C-type fender structure is formed of or -shaped composite column ( 54 ), which is the girders combined in vertical, and steel frame which is formed of beams( 51 ), columns ( 52 ) and laterally arranged C1 and C2 boards. The composite columns ( 54 ) may be placed at the corner of a building, the cross where outer and inner walls meet, the crisscross of inner partition walls, or any place for carrying the load , in the shape of , or -patterns. The foaming cement ceiling board ( 555 ) together with girders ( 334 ) can buildup a perfect fire resistant, lightweight floor slab( 333 ).
Example 3: As FIG. 4-5 shows, C-type integrated truss wall structure is formed of beams( 51 ), columns ( 52 ), braces ( 53 ) and C1, C2 boards. This fender structure, when used in buildings, should have steel columniation ( 222 ) set at the two ends of integrated truss. The columniation may be of various shaped steel columns, steel core concrete columns, special , or -shaped steel core concrete columns and composite columns with , or -shaped girders. This fender structure may be placed at the corner of a building, in the place where the outer and inner walls meet, in the place where the inner partition walls crisscross, and in any place as is required for carrying load of the building.
Application 4: As FIG. 4-6 shows, special C3-type board may be used as fire-proof decorative material for steel column ( 2 ) when the section size of steel column is larger than the thickness of wall.
As FIG. 5 shows, assembled partition board structure of this invention is the one where reinforcement ribs ( 6 ) are embedded in foaming cement(l); cement surface layer ( 4 ) strengthened with tension-resistant material ( 3 ) is coated on the surface of foaming cement(l); steel reinforcement( 2 ) are embedded in the binding area between cement surface layer ( 4 ) and foaming cement ( 1 ); joint channels ( 9 ) are on the right and left sides of the board; and fixation bolts ( 5 ) on top and bottom of the board with these bolts( 5 ) fastened to the reinforcement ribs ( 6 ).
As FIG. 6-1 shows, Example 1 is a decoration example of this invention. A decorative column which can be roughly shaped into a desired pattern with steel frame ( 5 ) is mainly formed by this airtight-cavity foaming cement ( 1 ) and a decorative surface layer( 4 ); the reinforcement ribs ( 6 ) are mechanically tied with the steel frame ( 5 ) and connected to the steel reinforcement( 2 ) in the binding area between decorative surface layer ( 4 ) and foaming cement ( 1 ); and the expansion joints ( 7 ) and fixation holes ( 8 ) may be embedded in said foaming cement.
As FIG. 6-2 shows, Application 2 is another decoration example of this invention: a stairway handrail is roughly shaped by the steel frame( 5 ); reinforcement ribs ( 6 ) are embedded in foaming cement ( 1 ); decorative surface layer( 4 ) strengthened with tension-resistant material ( 3 ) is coated on the surface; and steel reinforcement ( 2 ) is set in the binding area between foaming cement ( 1 ) and decorative surface layer ( 4 ). All these technical features work together to form a fire-proof, decorative stairway handrail.
As FIGS. 1 and 7 show, the steel structure construction method of this invention for old building renovation uses lightweight steel structure being capable to utilize the old solid-concrete foundation of existing buildings when increasing stories or altering the interior structure thereof by the method with large truss fender structure ( 13 ) plus steel columniation ( 222 ) outside. According to the calculation based on the weight of existing building and the load on its foundation, a corresponding floor of the old building is put down each time as a floor is added on top of it. A, B or C-type truss fender structure can be used as partition walls and A, B or C-type fender structure can be used as exterior walls. Together with assembled interior partition walls ( 66 ), shaped steel columns ( 223 ), floor slabs ( 333 ), structural decoration ( 44 ) and ceilings ( 555 ) therewith they provide an ideal method for the reconstruction. With the new building going up, the old one is demolished and reconstructed from top down. Thus, the general form of the old building is replaced entirely while the temporary supports ( 14 ) and cables ( 15 ) may be set during the construction.
Industrial Applicability
The construction of this invention is short in time while the design and operation thereof are easy to be standardized and industrialized. It has all the advantages of heat insulation, load-carrying decoration, fire resistance and proof, water proof and energy conservation. In addition, the overall costs become lower and room space expands. Because of its wide span, room can be rearranged in diverse manners with assembled partition wallboards and thus it is especially suitable for projects of rapid real estate development, urban reconstruction and urban-rural residential development as well. Good in earthquake resistance, the lightweight fender structures can benefit constructions in earthquake-prone regions and be a best choice for temporary houses in alleviating sufferings among disaster-stricken areas. When manufactured as industrialized production, it can be rendered as a highly integrated building with most of the construction works being finished in the factories. Heating facilities, air-conditioning, acoustic effects, kitchens, bathrooms, sports-rooms, exterior and interior decorations or other parts all can be done at one step in the factory and be assembled or installed on site as semi-products. The total construction costs are, therefore, reduced.
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A foaming cement ( 1 ), cooperates with the steel member ( 5 ), forms the fender structure ( 111 ), which could solely resist the load in horizontal or vertical direction, or cooperate with the columniation ( 222 ). The whole lightweight steel ( 5 ) is embedded in the foaming cement or the floor slabs. The fender structure ( 111 ) cooperates with the roof board, the ceiling ( 555 ) and the various floor slabs ( 333 ) in forming the structural system, which is capable of preserving heat and bearing the load and beautifying the environment.
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BACKGROUND OF INVENTION
Power supplied to an integrated circuit (IC) occurs through a power distribution network. The power distribution network starts with a power supply that generates an appropriate DC voltage. The power supplied to the IC must traverse from the power supply across the power distribution network before it reaches the IC. The power distribution network has characteristics that may affect the operation of the IC.
FIG. 1 shows a conventional IC system ( 10 ). The IC system ( 10 ) includes a printed circuit board (PCB) ( 12 ). The PCB ( 12 ) is a central platform on which various components are mounted. The PCB ( 12 ) has multiple layers that contain traces that connect the power supply and signals to the various components mounted on the PCB ( 12 ). Two layers, a system power supply layer ( 14 ) and a system ground layer ( 16 ), are shown in FIG. 2 .
The system power supply layer ( 14 ) and the system ground layer ( 16 ) provide power to an IC ( 20 ). The power supplied to the IC ( 20 ) traverses the system power supply layer ( 14 ) and the system ground layer ( 16 ) from a DC source (not shown) to a package ( 18 ) on which the IC ( 20 ) is mounted. Other components are also mounted on the PCB ( 12 ) that generally attempt to maintain a constant voltage supplied to the IC ( 20 ). These components may include, but are not limited to, an air-core inductor ( 24 ), a power supply regulating integrated circuit ( 26 ), switching transistors ( 28 ), a tantalum capacitor ( 30 ), and electrolytic capacitors ( 32 ).
A variety of different types and different locations of capacitors are used to help maintain a constant voltage supplied to the IC ( 20 ). Electrolytic capacitors ( 32 ) mounted on the PCB ( 12 ) connect between the system power supply layer ( 14 ) and the system ground layer ( 16 ). The package ( 18 ), similar to the PCB ( 12 ), may include multiple planes and interconnections between the planes to provide a connective substrate in which power and data signals traverse. Ceramic capacitors ( 22 ) mounted on the package ( 18 ) connect between a package power supply signal (not shown) and a package ground signal (not shown).
Due to active switching of circuit elements on the IC ( 20 ), the power required by the IC ( 20 ) changes. The active switching causes power supply noise. Additional components may be included to minimize such power supply noise. For example, ceramic capacitors ( 22 ) near the IC ( 20 ) act as local power supplies by storing and dissipating charge as needed.
The addition of components reduces the power supply impedance at most frequencies; however, localized impedance peaks may exist. The impedance peaks indicate a power supply resonance. The power supply resonance is formed when parasitics in the power distribution network and components connected to the power distribution network are excited at a particular frequency. The parasitics include the inherent inductance, resistance, and capacitance that may exist in the IC ( 20 ) (or other integrated circuits), package ( 18 ), and power distribution network. In particular, the power supply resonance may be formed from the power distribution network and a “parasitic tank circuit” that includes the chip capacitance and package inductance.
FIG. 2 shows a schematic of a power distribution network for an IC ( 296 ). The power distribution network is represented by impedances Z 1 ( 204 ), Z 2 ( 206 ), and Z 3 ( 208 ). Each of these impedances ( 204 , 206 , 208 ) may include resistive, inductive, and capacitive elements. Two power supply lines ( 292 , 294 ) supply power to the IC ( 296 ) located between the two power supply lines ( 292 , 294 ). The impedances ( 204 , 206 , 208 ) model both the inherent parasitics of the power distribution network and added components.
On the IC ( 296 ), various forms of chip capacitance may be used to further stabilize the power supply. Low equivalent series resistance (ESR) local decoupling capacitors are modeled by resistor ( 262 ) and capacitor ( 264 ). High ESR global decoupling capacitors are modeled by resistor ( 266 ) and capacitor ( 268 ). Non-switching logic on the IC ( 296 ) is modeled by resistor ( 270 ) and capacitors ( 272 , 274 ). Switching logic on the IC ( 296 ) is modeled by variable resistors ( 276 , 278 ) and capacitors ( 280 , 282 ).
In FIG. 2, the schematic of the power distribution network may be used to simulate the power supply impedance observed by the IC ( 296 ), as represented by “Z.” To measure the power supply impedance, a 1 Ampere AC current source ( 290 ) injects current onto power supply line ( 292 ). The measured voltage, VM, between the two power supply lines ( 292 , 294 ) may be used to calculate the power supply impedance. The impedance Z is equal to VM divided by the 1 Ampere AC current source ( 290 ). By varying the frequency of the 1 Ampere AC current source ( 290 ), a frequency versus impedance relationship may be determined.
A representative graph of power supply impedance is shown in FIG. 3 . Over a particular range of frequencies for the switching logic on the IC ( 296 ), the power supply impedance increases because the circuit formed by the chip and package resonates. A spike in a power supply impedance curve ( 302 ) has the effect of current-starving the IC ( 296 in FIG. 2 ). When the IC is current-starved, some voltage potentials on the IC ( 296 in FIG. 2) may shift from their desired values. Accordingly, an increase in the power supply impedance may cause undesired operation of the IC ( 296 in FIG. 2 ).
SUMMARY OF INVENTION
According to one aspect of the present invention, a computer system comprises a power distribution network arranged to propagate at least one voltage potential to an integrated circuit; a resonance detector arranged to detect a transmission from the integrated circuit to a receiver, wherein the transmission causes a power supply resonance; and a damping element operatively connected to the resonance detector and the power distribution network, where the damping element is on the integrated circuit, and where the damping element dampens the power supply resonance under control of the resonance detector.
According to one aspect of the present invention, a method for reducing a power supply resonance comprises propagating at least one voltage potential from a power supply to an integrated circuit; transmitting data from the integrated circuit to a receiver; detecting the transmitting for a transmission that causes the power supply resonance; and damping the power supply resonance dependent on the detecting.
According to one aspect of the present invention, an apparatus for reducing a power supply resonance comprises means for propagating at least one voltage potential from a power supply to an integrated circuit; means for detecting a transmission from the integrated circuit, where the transmission causes the power supply resonance; and means for damping the power supply resonance dependent on the means for detecting.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows a prior art integrated circuit system.
FIG. 2 shows a schematic of a power distribution network for an integrated circuit.
FIG. 3 shows a graph depicting power supply system impedance.
FIG. 4 shows a graph of I/O bit patterns in accordance with an embodiment of the present invention.
FIG. 5 shows a block diagram of a power supply resonance compensation system in accordance with an embodiment of the present invention.
FIG. 6 shows a block diagram of a resonance detector system in accordance with an embodiment of the present invention.
FIG. 7 shows a block diagram of a resonance detector system in accordance with an embodiment of the present invention.
FIG. 8 shows a schematic of a resonance detector and damping element in accordance with an embodiment of the present invention.
FIG. 9 shows a schematic of a resonance detector and damping element in accordance with an embodiment of the present invention.
FIG. 10 shows a graph depicting power supply system impedance in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
Embodiments of the present invention relate to a method for reducing power supply resonance.
Conventional approaches have focused on the clock frequency's relationship to the power supply resonance frequency. Much of the switching logic will operate at this frequency, and so if it closely matches the resonant frequency of the power distribution network, power supply resonance can be observed. However, even if the clock frequency is significantly different than the resonant frequency, certain patterns of transmitted bits may occur at the power supply resonant frequency, causing power supply resonance effects in a system.
FIG. 4 shows several exemplary bit patterns based on a 100 MHz clock frequency that may excite a circuit at frequencies other than 100 MHz. The clock signal ( 402 ) is shown on the top line of the graph. Input data bits in this clock's system are latched every 10 nanoseconds (at 5 ns, 15 ns, 25 ns, etc. in FIG. 5 ). The data is held steady during the positive clock edges.
The second line ( 404 ) on the graph shows an alternating bit pattern: “0101010101.” If a binary one is sent every other clock cycle, energy is input to the system every other clock cycle, for a resulting frequency of 50 MHz. The third line ( 406 ) on the graph shows the bit pattern: “0100100100,” inputting energy every third clock cycle. With this bit pattern, energy is input to the system at 33 MHz. The fourth line ( 408 ) on the graph shows a bit pattern with a binary one every fourth clock cycle, inputting energy at 25 MHz. The fifth signal ( 410 ) on the graph shows a different 25 MHz signal. The bit pattern is “0011,” and its duty cycle is 50%. Bit patterns with a 50% duty cycle have the strongest effect in inciting resonance. If any of the frequencies generated by a particular bit pattern matches the resonant frequency of the chip, the circuit may malfunction.
Data to be transmitted between integrated circuits passes through high power transmission amplifiers before being transmitted from one integrated circuit to another. These signals are greatly amplified on an integrated circuit and may have a relatively large effect on a power distribution network. If a frequency of data transmitted between integrated circuits occurs at a resonant frequency, the power distribution network may excite the power supply impedance spike described above. Accordingly, integrated circuits connected to the power distribution network may be current-starved and may malfunction. Data transmitted between integrated circuits is a significant contributor to switching-induced power supply resonance.
FIG. 5 shows a block diagram of a power supply resonance compensation system ( 500 ) in accordance with an embodiment of the present invention. In FIG. 5, a transmitting IC ( 510 ) is connected to a power supply ( 502 ) with two power supply lines ( 520 , 522 ). The transmitting IC ( 510 ) transmits data to a receiving IC ( 516 ) on line ( 518 ). The parasitic impedances Z 1 ( 504 ), Z 2 ( 506 ), and Z 3 ( 508 ) ( 204 , 206 , 208 shown in FIG. 2) are shown.
Embodiments of the present invention use a damping element ( 514 ) on the transmitting IC to dampen a power supply resonance and a resonance detector ( 512 ) to determine when the damping element ( 514 ) should be activated. The resonance detector ( 512 ) uses line ( 524 ) to control the damping element ( 514 ). Under non-resonant conditions, the damping element ( 514 ) should approximate an open circuit, thereby dissipating no power when it is not needed. The resonance detector ( 512 ) monitors transmissions between the integrated circuits ( 510 , 516 ) on line ( 518 ) and determines whether a transmission will cause a power supply resonance condition. If a transmission is determined to cause a power supply resonance condition, the resonance detector ( 512 ) will activate the damping element ( 514 ) so that the damping element ( 514 ) may damp the power supply resonance.
According to one or more embodiments of the present invention, the resonance detector ( 512 ) may store a list of bit patterns known to cause power supply resonance. Transmissions monitored by the resonance detector ( 512 ) would be compared to the list of offending bit patterns. Upon discovery of such a pattern, the resonance detector ( 512 ) enables the damping element ( 514 ) to dampen the impending power supply resonance caused by the offending bit pattern.
Because the first bit of an offending bit pattern may come at any time in a series of bits, a shift register may be used as part of the pattern detecting system. The bits to be transmitted would be fed through the shift register so that the pattern being transmitted could be “moved” with respect to the pattern it is being compared to. If at any time during the transmitted pattern's traversal of the shift register the transmitted pattern matches the pattern it is being compared to, the resonance detector ( 512 ) has detected an offensive bit pattern.
According to one or more embodiments of the present invention, the resonance detector ( 512 ) may perform a frequency analysis on the transmitted data signal. A frequency analysis algorithm may be used to determine the frequency content of the signal. Fourier analysis (e.g., Fast Fourier Transform) or wavelet analysis may be used to determine the frequency content of the signal. After determining the resonant frequency of an integrated circuit and power distribution network combination, frequencies generated by offending bit patterns are programmed into the resonance detector ( 512 ). During operation, bit patterns are transformed into the frequency domain, and the resonance detector ( 512 ) in turn looks for frequency content near the resonant frequency. The damping element ( 514 ) may be enabled if the signal contains enough energy near the resonant frequency to induce power supply resonance.
Signal frequency content near harmonics of the resonant frequency (i.e., frequencies that are integer multiples of the resonant frequency) may also cause power supply resonance. In one or more embodiments, a frequency analysis-based resonance detector may be programmed to be responsive to harmonic frequencies of the resonant frequency as well as the resonant frequency itself.
In FIG. 5 the resonance detector ( 512 ) is shown as a part of the transmitting IC ( 510 ). One of ordinary skill in the art will understand that the resonance detector ( 512 ) may also be included as a part of the receiving IC ( 516 ), or it may be included on a third IC (not shown) separate from the transmitting IC ( 510 ) and the receiving IC ( 516 ). The resonance detector ( 512 ) may also be a separate IC on the package of either the first or second IC.
FIG. 6 shows a block diagram of a resonance detector system in accordance with an embodiment of the present invention. Data transmitted on line ( 604 ) is sent to the resonance detector ( 602 ). The resonance detector ( 602 ) includes a data buffer that latches the transmitted data for analysis. The transmitted data is then passed on to the intended receiver on line ( 606 ). If the resonance detector ( 602 ) determines that a transmission will cause power supply resonance, the resonance detector ( 602 ) activates the damping element (not shown) using line ( 608 ).
One of ordinary skill in the art will understand that other configurations are possible. FIG. 7 shows a block diagram of an exemplary resonance detector system in accordance with an embodiment of the present invention. The resonance detector ( 702 ) may monitor transmissions between integrated circuits without being disposed between transmitter (not shown) and receiver (not shown) as in FIG. 6 . One of ordinary skill in the art will understand that lines ( 704 ), ( 706 ), and ( 708 ) represent the same electrical node. Data to be transmitted is sent on line ( 704 ), which splits into lines ( 708 ) and ( 706 ). Line ( 708 ) continues to carry the data on to the intended receiver, while line ( 706 ) supplies a copy of the transmitted data to the resonance detector ( 702 ). If the resonance detector ( 702 ) determines that a transmission will cause power supply resonance, the resonance detector ( 702 ) activates the damping element (not shown) using line ( 710 ).
As shown in FIG. 8, according to an embodiment of the present invention, a damping element ( 802 ) may be a resistor ( 804 ) in series with a PMOS transistor ( 806 ) operating as a switch. A resonance detector ( 814 ) supplies a high voltage potential to the gate of the transistor under non-resonant conditions, so that the damping element ( 802 ) is essentially an open circuit. When a power supply resonance-inducing transmission is detected, the resonance detector ( 814 ) supplies a low voltage potential to the transistor ( 806 ) using line ( 808 ), causing the transistor ( 806 ) to behave as a short circuit, thereby creating a resistance between the two power supply lines ( 810 , 812 ). The resistor ( 804 ) between the power supply lines ( 810 , 812 ) will dampen the power supply resonance. When an offending transmission is over or damping is no longer required, the resonance detector ( 814 ) will turn “off” the transistor ( 806 ).
One of ordinary skill in the art will understand that an NMOS transistor could also be used in this configuration. The NMOS transistor may connect to power supply line ( 812 ) with the resistor ( 804 ) connected to power supply line ( 810 ). The resonance detector ( 814 ) applies a voltage to the gate of the NMOS transistor while a power supply resonance inducing transmission is detected.
Those skilled in the art will note that the control scheme used for this switch-mode operation is called “bang—bang control” because the control signal “bangs” between two discrete values (i.e., ON and OFF) as some parameter (i.e., frequency of transmitted bits) enters and leaves an appropriate operating range (i.e., near resonance and away from resonance, respectively).
As shown in FIG. 9, according to an embodiment of the present invention, a damping element ( 902 ) may be a digital potentiometer ( 904 ) under control of a resonance detector ( 914 ). The resonance detector ( 914 ) sends control information on a line ( 908 ) to the potentiometer ( 904 ) that controls the resistance between the two power supply lines ( 910 , 912 ). For proper operation under non-resonant conditions, the potentiometer ( 904 ) may be set to a very high resistance so that it may act as an open circuit.
A potentiometer ( 904 ) has the advantage of being tunable and continuously variable. If the resonance detector ( 914 ) detects a transmission that may cause a small power supply resonance, the resonance detector ( 914 ) may respond appropriately by setting the potentiometer ( 904 ) to a slightly lower value than its open circuit mode. Accordingly, the power supply resonance is effectively damped while the damping element ( 902 ) dissipates as little power as necessary. If the resonance detector ( 914 ) detects a transmission that will induce a larger power supply resonance, the resonance detector ( 914 ) may set the potentiometer ( 904 ) to relatively low resistance value to dampen the larger power supply resonance.
In one or more embodiments, various different control schemes may be used to control the damping element ( 902 ). Proportional, integral, differential (PID) control is one control method that could be employed by the resonance detector ( 914 ). The resonance detector's ( 914 ) PID parameters may be selected to optimize at least one aspect of the system's performance. Depending on the application, the goal of the optimization may be to minimize the amplitude of a power supply resonance, to minimize the duration of a power supply resonance, or to minimize power dissipated by the damping element.
One of ordinary skill in the art will understand that there are many other potential embodiments of a damping element. The minimum requirements are that the damping element be controllable by a resonance detector, and that the damping element be able to dampen a power supply resonance. In one or more embodiments, the power supply resonance is dampened by lowering a power supply impedance.
FIG. 10 shows a graph depicting power supply system impedance in accordance with an embodiment of the present invention. Power supply impedance curve ( 1002 ) displays a power supply impedance curve ( 1002 ) without the influence of the present invention as shown in the power supply impedance curve ( 302 ) in FIG. 3 . Power supply impedance curve ( 1006 ) shows a relationship of impedance to frequency under the influence of the present invention. Away from the resonant frequency, the two power supply impedance curves ( 1002 , 1006 ) are approximately equivalent. Accordingly, a damping element is an open circuit at these frequencies. In other words, at such non-resonant frequencies, the damping element, for example damping element ( 802 ) in FIG. 8, has no effect on the power distribution network. Near the resonant frequency, the resonance detector activates the damping element, for example damping element ( 802 ) in FIG. 8, and the power supply resonance is attenuated.
Advantages of the present invention may include one or more of the following. In one or more embodiments, the present invention may dampen a power supply resonance in a power distribution network, thereby improving system performance.
In one or more embodiments, the present invention may limit the amount of power dissipated by the damping element while still effectively damping power supply resonance.
In one or more embodiments, the present invention may allow control over how a power supply resonance is damped. Amplitude of the power supply resonance, duration of the power supply resonance, or power dissipated by the damping element may be minimized.
Some power supply resonance-inducing transmissions may occur unpredictably. In one or more embodiments, the present invention may detect such power supply resonance-inducing transmissions, and the resulting power supply resonance may be damped.
In one or more embodiments, the present invention's damping element will only dissipate power when a power supply resonance exists and requires damping, thereby dissipating power only when needed.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
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An apparatus for compensating for the effects of resonance in an integrated circuit's power distribution network is provided. A resonance detector monitors transmissions from the integrated circuit for certain bit patterns that may excite the power distribution network at a specific frequency and cause power supply resonance. Power supply resonance causes an increase in power supply impedance. When offending transmissions are detected, the resonance detector activates a damping element on the integrated circuit which dampens the resonance. The damping element is a resistive device between two power supply lines that decreases power supply impedance when activated.
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BACKGROUND OF THE INVENTION
This invention has to do with patient isolation rooms, and more particularly, is concerned with improvements in known patient isolation rooms whereby the patient is maintained isolated from room air beyond the patient locus so that the patient is not exposed to potentially bacteria- and/or virus-contaminated air carried by hospital personnel or others co-present in or about the room with the patient. Apparatus is provided to achieve horizontal, unidirectional, laminar air stream flow of uniform velocity throughout its cross-section linearly across the patient locus, whereby cross-streams such as may be present in prior known rooms, which cross-streams may carry bacteria- and/or virus-contaminated air across the patient locus, are obviated.
For effective care of patients undergoing physically debilitating treatments such as chemotherapy to ameliorate cancerous conditions, and others especially susceptible to infection, such as burn victims, it is essential to isolate the patient as much as possible from sources of infection. Conversely, it is desirable to protect hospital personnel from infectious patient conditions. For these purposes, there have been developed "isolation rooms" which are spaces within the hospital having controlled air sources and which generally are operated under a positive pressure to exclude contamination to the maximum degree. Some of these rooms provide accordian folding walls equipped with viewer isolating viewports and associated hand glove ports for care of the patient while providing nearly total isolation from infection. State of the art viewports, however, are curved at critical areas, giving an optically distorted view of the patient. This invention provides a solution to this problem. Further, the present invention relates to virustatic control for patient isolation rooms.
PRIOR ART
As presently known, isolation rooms in hospitals are constructed to have at one end wall a bank of High Efficiency Particulate Air filters, termed HEPA filters in the art, which are arranged in a bank of vertical and horizontal rows of filters. A blower as a source of pressurized air is provided to force air to be purified, e.g. bacteria purged, through the HEPA filters. The air stream, as thus purified, is wafted across the bed defining the patient locus, and then recovered for recirculation. Recovery of the purified air leaving the patient is necessary for filtration economy, but has been a problem. In one form of the isolation room, there is provided outside of the room itself an air return system comprising a gross, non-HEPA filter leading to the intake of the blower being used to pressurize air for passage through the HEPA filters. Generally, these air circulation systems use the room doorway as an air outlet passage. This arrangement is deficient in at least two significant respects: The location of the patient's bed is often adjacent the viewport sidewall so that the patient may be most easily treated, and the corner doorway therein becomes the air outlet. All airstreams emanating from the HEPA filter bank are funnelled toward that doorway corner. When a doctor or other medical person is within the room and next to the patient's bed, the cross current, which is produced by the room air flow narrowing from the width of the filter bank wall to the width of only a doorway of the room, carries the bacteria and/or virus contaminants of the doctor or other hospital person across the patient locus, defeating the isolation function of the room. Even standing in the doorway sets up eddies and backwash air flows which can carry contaminants back into the room, although the air flow is primarily out the door. The corner doorway outlet arrangement is further deficient because of the resultant inability to maintain closed the doorway to the room. Children have been known to wander through an open doorway and leave the room. Use of half-doors has been tried to block the child's egress, but this expedient likewise blocks full air flow through the outlet, since the half-door acts as a baffle, increasing the funnelling effect experienced at the door opening, and doubling intended outlet air flow from 300 to 600 feet per minute. Moreover, no door, or only a one-half door, precludes protection of hospital personnel from contagious patient conditions, since the depurified air stream is unconfined at the doorway and may pervade other hospital spaces.
SUMMARY OF THE INVENTION
It is, accordingly, an object of the present invention to provide an improved patient isolation room. It is a further object to provide a patient isolation room in which air flow is horizontal, unidirectional and laminar and of uniform cross-section velocity throughout the patient locus. It is yet another object to provide a patient isolation room in which horizontal, unidirectional and laminar purified air streams encompass the patient locus on every side, linearly and without cross-streams, and thus without contamination of the patient locus by doctors or hospital personnel present in the room. Yet another object is to provide a patient isolation room in which the air inlet-outlet system permits the room door to be closed without blocking air recirculation through the room, thus obviating eddying and other turbulences about the doorway and their concomitant contamination. It is a further object to provide a more economical isolation room construction through the use of overhead air recirculation; and, with air recirculation which is quieter in use than patient isolation rooms heretofore known. It is a still further object of the invention to provide a more highly purified air stream to the room through the elimination of viral e.g. influenza contaminants as well as bacterial agents. It is a further and highly advantageous object to provide apparatus for the repetitive and automatic virustatic conditioning of the air stream during recirculation to and from the patient isolation room. It is another object to virustatically treat humidifying water to be passed into a patient isolation room, thereby controlling another source of difficulty in operation of such rooms, and as well to render HEPA filterable the viral agents, if any, within the air which are not normally so filterable.
These and other objects of the invention are realized in accordance with the apparatus hereinafter described, which comprises, in general, a patient isolation room having side, top and bottom walls surrounding a relatively smaller patient locus, and continuous air flow loop means isolating said locus from airborne contaminants beyond the locus, the loop means within the room including an inlet and outlet relatively sized and oppositely arranged to encompass the patient locus on every side with a purified, horizontal, unidirectional laminar air stream of uniform velocity throughout its cross-section, the loop means beyond the room conducting depurified air from the loop outlet above the room top wall for repurification and recirculation. Typically, the air flow loop means further includes the room air inlet being adjacent the patient locus, and an air purifying filter means adapted to pass purified air to the inlet for horizontal, unidirectional, laminar, cross-sectionally uniform flow therefrom toward the locus. The air flow loop means room air stream outlet is typically adapted to draw the air stream entering at the room inlet horizontally and unidirectionally across the patient locus to define with the inlet the mentioned locus encompassing relation. Further, the air flow loop means may include a blower beyond the room in air-drawing communication with the room outlet and in pressurized air communication with the room inlet.
In preferred embodiments, the air flow loop means includes a portion defining a closed passage above the room top wall receiving and passing across the top of the room contaminated or depurified air streams recovered from the room, in isolated relation for repurification and recirculation. The air stream outlet in such embodiments may comprise a first wall port spaced above the plane of the room bottom wall and horizontally and vertically extended to receive the horizontal air streams traversing the patient locus in the noted encompassing relation.
There may be provided a high efficiency, particulate air (HEPA) or other effective filter means in the air flow loop means, the air stream inlet comprising a second wall port adjacent the patient locus in air filter communicating relation with the filter means; the room air inlet port and outlet port being respectively horizontally and vertically extended, e.g. the inlet port being approximately commensurate with the air filter means, and opposed across the interior of the room, to traverse the patient locus with a purified air stream dimensioned to continuously encompass the locus on all sides during air stream passage between the inlet wall port and the outlet wall port.
In particular embodiments, the outlet first wall port is formed in a room side wall and the second inlet wall port is formed in the side wall opposite the outlet wall, to define the opposed relation of the inlet wall port and the outlet wall port. Alternatively, the outlet, first wall port may be formed in the room top wall (or ceiling) and the second, inlet wall port in the room side wall beyond the patient locus, relative to the first, outlet wall port, to define the opposed relation of the inlet wall port and the outlet wall port.
Further features of the apparatus include foreclosing room contamination from the closed passage above the room from dust and other contaminants above the room ceiling indraughted through spaces between ceiling panels, by having the room and closed passage dimensioned to have the air stream volume within the room and the closed passage (below the room top wall) flow as an air stream of lower velocity within the room which is of course thus relatively larger in volume, than the air stream beyond the room above the top wall (in the closed passage), which is of course thus smaller, relatively, in volume, the net effect being to draw contaminants upward from the room through any leakage points in the top wall by Venturi action, the Venturi action acting against room contamination from the passage through the room top wall.
Together with these features, the apparatus in its preferred embodiments also includes, as in other embodiments, in the loop means: an air blower communicating negative pressure to the room outlet wall port through the closed passage and positive pressure to the inlet wall port through the air filter; in the room: the outlet first wall port, being formed in a room side wall, and the second, inlet wall port, being formed in the room side wall opposite the outlet wall port to define the opposed relation of the inlet wall port and the outlet wall port; and withal the room and closed passage being relatively dimensioned to have a lower velocity air stream within the room below the top wall than beyond the room against room contamination from the passage through the room top wall.
Still other features include the patient locus being immediately adjacent a room side wall free of inlet and outlet wall ports, and the invention apparatus providing a viewport positioned in this locus-adjacent wall in patient viewing relation for a viewer outside the room, the viewport comprising an inwardly projecting panel assembly including a first, transparent planar panel extending angularly upward from the room wall a distance to provide a nonaberrant view downward of a patient within the patient locus, and at least one additional panel supporting the first panel in its position on the wall in viewer isolating relation.
Yet another feature of the herein disclosed apparatus is the distributive provision of a supply of virustatic material, and air pervious reticular structure positioned across the air flow path within the loop carrying the material supply in labyrinthine relation for random and repeated contact with air flowing in the loop to control virus in air flow loop air. In particular embodiments, the air flow loop means may further include a humidifier adapted to generate moisture vapor for entrainment in the loop air flow by water assisted evaporation of stored water, and the apparatus include also a biostatic material supply, and means to meter the supply material into the stored water to control virus and bacterial growth in the stored water.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described as to illustrative embodiments thereof in conjunction with the attached drawings, in which:
FIG. 1 is a perspective view of one form of patient isolation room according to the invention, featuring a top mounted blower and a ceiling air outlet to a loop air flow passage above the room;
FIG. 2 is a side view in vertical section thereof;
FIG. 3 is a view like FIG. 2 of another form of the invention featuring an end wall air outlet to the loop flow air passage above the room;
FIG. 4 is a perspective view of the presently preferred alternative embodiment of the invention, featuring a side mounted blower and the ceiling air outlet to a loop flow passage above the room and to the blower;
FIG. 5 is a detail view, greatly enlarged, of the recirculating air blower system taken on line 5--5 in FIG. 4;
FIG. 6 is a view in vertical section taken on line 6--6 in FIG. 5;
FIG. 7 is a detail horizontal section view of the HEPA filter element, greatly enlarged, taken on line 7 in FIG. 6; and
FIG. 8 is a front plan view of the HEPA filter element taken on line 8--8 in FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
System Overview
In each of the several embodiments now to be described, a blower-pressurized bank of HEPA filters is the source of a "piston" of purified air which moves through the patient locus laminarly, unidirectionally, horizontally and with uniform velocity throughout its cross-section. In each embodiment, an outlet for the air so moving is provided in a size, configuration and location relative to the HEPA filter bank as to enable the just described air movement. Between the air inlet and air outlet a wall-less passage is defined free of pinching or funneling effects and the patient locus is encompassed within this passage, thus isolated by the air curtain effect of the air stream flow at the peripheries of the patient locus. In each embodiment, the air is captured in a negative pressure outlet in the ceiling or in a room vertical wall outlet and carried back to the HEPA filter bank, with blower repressurization, and optionally viral conditioning and gross filtration, through a closed or walled passageway provided at least partially above the isolation room ceiling.
First Embodiment
With reference now to the drawings in detail, the first embodiment is shown in FIGS. 1 and 2. This first embodiment is characterized by a ceiling air outlet or return, an overhead blower installation, and an improved type of viewport according to the invention. Thus the patient isolation room 10 is seen to comprise four rectangular vertical walls 12, 14, 16 and 18, a horizontal bottom wall 20 as a floor and a horizontal top wall 22 as a ceiling. Room 10 is typically set up inside an existing hospital room on an existing hospital corridor. Thus hospital room walls, e.g. walls 24, 26 and others not shown may enclose the patient isolation room 10. The room 10 ceiling is formed of rectangular plastic panels 28, supported by a tie bar 30 and grid 32 arrangement, below the normal hospital room plaster ceiling 34 which in turn is below the structural reinforced concrete flooring 36 for the next story of the hospital building. Thus the patient isolation room 10 is set up apart from other hospital spaces.
The locus L of the patient in the room 10 is determined by positioning of bed 38. Conventionally for cancer victims this location is as shown in FIGS. 1 and 2, alongside side wall 18. Burn victims may be desirably positioned alongside wall 12.
Wall 18 may be in a hospital corridor or within a larger room space and is shown to include a doorway 40, a split door 42, a pair of glove ports 44 carried by a flexible transparent member 46 for translational movement. A viewport 48 is also provided, carried by member 46 in wall 18. Viewport 48 comprises a first planar transparent panel 50 extending upwardly and inwardly from member 46 to provide an untrammelled and nonabberant view of the patient in locus L by virtue of the planarity of the viewport in the line of vision of the person outside the room to the patient. Old style "bubbles" were shaped like airplane cockpit canopies and were curved at the critical intersection with the normal line of sight and gave distorted images. A second and shorter upper panel 52 and side panels 54 support the view panel 50 in its place on the member 46 and complete the viewport assembly.
Wall 12 forms one end of the room 10 and comprises a perimetrical frame 56 which encloses and supports a bank 58 of HEPA filters 60, shown in structural detail in FIGS. 5, 7 and 8. Wall 12 is spaced from hospital room wall 26 to define a plenum 62 for purposes to be described, and defines a room air inlet port I commensurate with the extent of the HEPA filter bank 58.
Walls 14 and 16 complete the vertical walls of the room 10 and may be plain or windowed at 64 as shown. Bottom wall 20 is typically the conventional hospital flooring.
Top wall 22 is the room ceiling as noted earlier, and in this embodiment of the invention it is provided with a generally rectangular opening 66 into which a reticulated grill 67 is inserted. The opening 66 defines a room air outlet port 0 commensurate with the opening. It will be noted that the outlet 0 (opening 66) is oppositely arranged to the inlet I (filter bank 58) across the patient locus L (bed 38) and that air streams entering at I will traverse the locus L and encompass the locus on every side in passing to the outlet 0.
Above the room ceiling or top wall 22 a closed passage 68 in communication with opening 66 is defined by the normal plaster ceiling 34 above, and room wall skirts 70, 72, 74 and 76 which peripherally enclose the above ceiling space as the room walls 12, 14, 16 and 18 do below the ceiling. Skirts 70-76 are not necessarily or even preferably continued extents of the room walls 12-18 but may be of any arrangement defining the closed passage 68 as a space of less volume than room 10 for purposes mentioned herein. Also in communication with the closed passage 68 are the intakes 78 of blowers 80. Blowers 80 are mounted on framing 82 above the plenum 62 and arranged so as to exhaust blower pressurized air into the plenum (see FIG. 2). Thus arranged, the blowers 80 indraught air in the closed passage 68 from opening 66, which is possibly depurified or "contaminated" by passage through the room 10, by inducing a negative pressure in the passage 68 as though the passage were an extension of the blower inlet. This negative pressure draws air into opening 66 within room 10. The filter bank 58 is in open communication with plenum 62 which it will be observed is at a super pressure. Air passes through the filter bank 58 with a pressure drop typical of HEPA filters and across the patient locus L under the influence of opening 66 whereby the inlet I and outlet O cooperate to pass the air stream across the locus in unidirectionally laminar relation, and at a uniform velocity in cross-section throughout locus L. Beyond the locus L the air streams tend upward and enter the opening 66 (see arrows FIG. 2). It is noteworthy that the substantial horizontal extent of the opening 66 enables air stream traversal of the patient locus L without lateral pinching or a horizontal cross-current, obviating non-linear air flows which can cause carriage of contaminants from beyond the locus into the locus.
Note to that the door 42 is kept closed during room operation, eliminating child wandering, eddies and backward currents from doorway standing of personnel, and contamination of hospital corridors and other spaces with room air, and enabling facilitated air conditioning and purification performance in a closed system.
A supplemental filter 84 supported by framing 86 is provided downstream of the ceiling opening 66. This filter 84 is typically of low efficiency and made of polyester or other fibrous mat; its purpose is to prolong the life of the high efficiency HEPA filters by screening out gross contaminants such as dust. In a further aspect of this invention, filters such as filter 84 may be used to define an air pervious structure which may be coated as to its individual fibers with a persistant quaternary ammonium compound or mixture of such compounds such as that sold under the trade name Control III which are demonstrated virustatic compounds. Thus coated, and recalling the labyrinthine path through a mat of such fibrous material, the filter 84 describes an intricate maze for air flow, virus carried in the air will collide randomly and repeatedly with the fiber coating, being killed or deactivated in the process whereby the air leaving the filter 84 is purified of live virus. Bacteria, of course, will likewise be killed, but these are of less concern since the HEPA filters 60 are able to filter out bacteria before the recirculated air is returned to the room 10.
It is additionally to be noted that the volume of closed passage 68 being less than the volume of room 10, and the quantum of air flowing through each being the same, that the velocity of air in the passage is greater than in the room. Thus any surface air flow effects along the ceiling, e.g. Venturi suctions will tend to draw air upward between ceiling panels 28 and grid 32 so that dust, dirt and plaster accumulations and bacterial contaminants in the passage 68 are not drawn downward into the room.
Second Embodiment
Turning now to the embodiment of FIG. 3, the room 10 arrangement is similar to FIGS. 1 and 2 except that in this embodiment the end vertical wall 16, noted as wall 161, is modified to comprise front and rear elements, the rear element 162 being solid and the front element 163 having an opening 661 formed therein, analogously to opening 66 in ceiling 22 of the FIG. 1 embodiment, and likewise provided with a grill 671 to define outlet port O. In the FIG. 3 embodiment, the air passed into the room 10 by HEPA filter bank 58 traverses the patient locus L flowing in a horizontal, laminar and unidirectional manner and encompassing the locus on every side, the outlet port 0 being so constructed and arranged as to horizontal extent (width) and height per se and of spacing above the plane of floor 20 relative to the inlet port I (the bank 58) and the locus L (bed 38) that the air piston envelopes the bed continuously and linearly. The FIG. 3 embodiment is shown to employ the overhead mounted blower 80, but a sidemount blower may be used with appropriate alterations in the closed passage 68 as in FIG. 4 now to be described.
Third Embodiment
The embodiment of FIG. 4 is the currently preferred form of the invention because of the ease of installation and the present state of the art of side-mount blowers. In this embodiment of blowers 80 do not need to be ceiling mounted, but the advantages of a closed passage 68 above the room ceiling is retained. Thus, and with particular reference to FIGS. 4, 5 and 6, the room 10 setup is like the FIG. 1, 2 embodiment with the same walls 12-18 located within the same hospital space as there described. Proceeding to the different aspects of this embodiment, the room 10 top wall 22 has a horizontal continued extent 22a which projects beyond the viewport 48. Wall 18 skirt 76 is likewise displaced as shown. This wall extent 22a is provided with a secondary outlet 88 whereby the closed passageway begins with the room outlet port O (opening 66) and ends with secondary outlet 88. A side mounted pair of blowers 80 is provided in cabinet 90, a generally rectangular structure which houses the blowers supported on framing 92, their inlets oriented to the perforate grill 94 of the cabinet and their outlets with baffles 96, oriented toward the plenum 62 between the HEPA filter bank 58 and hospital room wall 26. Blower operation is regulated through console controls 98. A series of prefilters 84 between the grill 94 and the blower intake 78 serve to filter gross particles, and may be provided with virustatic control agents as in the FIG. 1 embodiment. A cooling coil 100 for temperature control of the recirculating air is provided behind the prefilters 84.
With more particular reference to FIG. 6, there is shown a further innovation according to the invention. A conventional humidifier device is shown at 102 comprising a tank 104 for storing water 106. A heating coil 108 controllably evaporates water into the recirculating air to maintain a desired level of humidity, e.g. 50% for chemotherapy uses and 90% or more for burn victims. It has been observed that the stored water 106 is a fertile multiplying medium for bacteria and virus which once in the water may multiply drastically, ultimately to enter the room. This problem is obviated by provision herein of a virustatic control in the form of a metering container of liquid virustatic agent, e.g. one or more quaternary ammonium compounds, e.g. Control III, which are dripped into the stored water 106 at a predetermined rate from the inverted supply bottle 110 supported in place by the top wall 112 of tank 104.
While not forming per se a part of the present invention, this structure of the HEPA filters used herein comprise, with reference to FIGS. 7 and 8, reversely folded or accordion pleated fiberglass cloth 113 of high density, interleaved with spacers 114 which comprise fluted or corrugated aluminum or the like, to define a series of flow passages 116. The assembly of fiberglass cloth folds and aluminum spacers is tightly compressed and secured in a frame (not shown) to enable effective filtration of air containing contaminants as small as 0.3 micron with up to 99.97% efficiency. This level of filtration effectively removes bacteria, which are above 0.3 micron up to about 13 microns in size.
As noted, it is a further feature of the invention that destruction of virus-sized contaminants is provided. Thus virus which have a particle size typically 0.002 to 0.015 micron may be filtered by humidifying the air passing through the air flow loop, by the attachment of water droplets, effectively increasing the size of the virus to HEPA-filterable dimensions. In a further described features of the invention, prefilter 84 medium is coated with a virustatic material e.g. Control III (tradename), which is added in virustatically effective amounts into the humidifying water normally added to the air stream for patient comfort. It has been found that the addition of from 200 to 500 parts per million of the virustat, Control III, to the humidity water supply effectively controls virus levels.
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A patient isolation room having walls surrounding a relatively smaller patient locus, with continuous air flow loop including an air inlet and outlet relatively sized and oppositely arranged to encompass the patient locus on every side with a horizontal, unidirectional, laminar air stream of uniform velocity throughout its cross-section to maintain patient isolation from room air beyond said locus, the loop conducting depurified air beyond the room for recirculation and repurification.
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BACKGROUND
1. Field of the Invention
This invention relates to the art of pump control systems.
More particularly, the invention relates to a system for controlling and monitoring all the functions of a mobile fire pump apparatus having an electronically-controlled engine.
In a further and more specific aspect, the instant invention concerns a comprehensive electronic system for controlling the flow of fluids through an engine-driven fire pump.
2. Description of the Prior Art
Over the years, various systems have been devised for controlling engine-driven fire pumps. For instance, U.S. Pat. Nos. 3,786,689 and 4,189,005 to McLoughlin, as well as U.S. Pat. No. 5,888,052 to McLoughlin et al., disclose apparatus for controlling the pressure output from engine-driven centrifugal fire pumps. Likewise, U.S. Patent Application Publication No. 2005/0061373 to McLaughlin et al. discloses a system for regulating the fluid intake pressure of a pumping system, while U.S. Pat. No. 7,040,868 and U.S. Patent Publication No. 2005/7,040,868, both to McLoughlin et al., disclose systems for controlling pumping speed during discharge pressure fluctuations. Each of the aforementioned systems is somewhat limited in that it is designed primarily for the control of a single parameter (i.e. discharge pressure, intake pressure, or pump speed). None is a comprehensive system for simultaneously monitoring all the aspects of both fluid flow and engine performance. Furthermore, each of these systems is designed to control the flow of a single fluid (typically water) and does not include means for controlling the flow of any supplementary fluids, such as firefighting foam, which may be added to the discharge.
Accordingly, there exists a need for a comprehensive control system for simultaneously monitoring and controlling all the functions of an engine-driven mobile pumping apparatus.
SUMMARY OF THE INVENTION
Briefly, to achieve the desired objects of the instant invention in accordance with the preferred embodiments thereof, a system is provided for simultaneously monitoring and controlling all the functions of an engine-driven mobile pumping apparatus. Specifically, the system includes an engine-driven primary pump, an intake system for delivering liquid to the pump, and a discharge system for dispensing liquid from the pump. The intake system includes a supply line that is coupleable to both a reserve tank and a pressurized source, as well as an intake pressure sensor for monitoring the pressure upstream of the pump and an intake pressure regulating system for maintaining the intake pressure above a preset low inlet pressure P LOW . The discharge system includes at least one hose terminating in a discharge nozzle, a discharge pressure sensor for monitoring the pressure downstream of the pump, and a discharge pressure regulating system for maintaining the discharge pressure below a preset maximum discharge pressure P MAX The intake and discharge regulating systems are controlled by a master processor that also monitors and records various other conditions of the system such engine speed, voltage, current, temperature, and sends information about these conditions to the vehicle's control display and/or warning systems.
In a preferred embodiment of the invention, the intake system includes a first conduit coupleable to the pressurized source, a second conduit coupleable to an inlet opening in the reserve tank, and a third conduit coupleable to an outlet opening in the reserve tank. The intake pressure regulating system includes control valves in the first, second, and third conduits.
The discharge system in this embodiment includes a discharge valve in the at least one discharge hose, and a pressure relief valve upstream of the primary pump.
The system is programmed such that at start up, only the valve in the third conduit is open, so that the initial intake pressure is proportional to the level of water in the reserve tank. If the discharge pressure is lower than a preset minimum level P MIN , a priming pump is actuated until P MIN is reached. When P MIN is reached, the priming pump switches off, but the valve in the third conduit remains open, and the other two valves stay shut until the discharge pressure sensor detects that that a preset desired output pressure P D (typically somewhere between 100 and 150 psi) has been reached. At this point, if there is a pressurized source available, the valve in the third conduit is closed, and the valve in the first conduit is opened, so that water for the pump is supplied from the pressurized tank rather than from the reserve tank. Also, if the liquid level in the tank is below a preset minimum, the valve in the second conduit opens, allowing a portion of the liquid in the pressurized source to be diverted into the tank. As soon as the liquid level rises to its desired level, the valve in the second conduit closes again.
From this point onward, the system is maintained at more or less steady state by the engine governor, which responds to changes in discharge pressure by varying the RPM of the engine and/or actuating the relief valve, as needed. If the intake pressure suddenly drops below a preset low value P LOW , the valve in the third conduit reopens, allowing liquid from the tank to enter the system at a pressure proportional to the water level. When the intake pressure goes back over P LOW , this valve closes and the valve in the first conduit second conduit reopens, allowing the tank to be refilled.
Other components of the system include foam pumps for dispensing various firefighting foams, an air compressor for delivering rescue air to the firefighters, and a tank of compressed nitrogen or other non-flammable gases. Operation of all of these components is controlled by the master processor.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and further and more specific objects and inventions of the instant invention will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment thereof taken in conjunction with the drawings, in which:
FIG. 1 is a schematic drawing of a control system according to the present invention;
FIG. 2 is a control block diagram of the system; and
FIGS. 3 a - i are graphs showing the operation of various elements of the system over time.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning to the drawings in which like reference characters indicate corresponding elements throughout the several views, attention is first directed to FIG. 1 , which shows a schematic diagram of the control system 10 for a mobile pumping apparatus such as a fire truck (not shown). A gasoline or diesel engine 12 is mechanically coupled to a main centrifugal pump 14 having a supply line 16 which is coupleable to multiple fluid sources such as, for instance, a truck-mounted water tank 18 and a fire hydrant 20 . Various arrangements may be used for coupling the supply line 16 to the water tank 18 and the hydrant 20 , but in the illustrated embodiment, the terminal end of the supply line 16 is connected to an inlet manifold 21 that connects to a first hose 22 leading to the hydrant 20 and a second hose 23 leading to an inlet opening 24 in the water tank 18 . The second hose 23 includes a one-way check valve 25 preventing water from the tank 18 from flowing out towards the hydrant 20 . In addition, a third hose 26 leads from an outlet opening 27 in the tank 18 to the inlet manifold 21 .
The discharge line 30 of the pump 14 is coupled to a discharge manifold 31 having a plurality of openings 32 a, b . . . n, each of which may accommodate a fluid conduit 33 a, b . . . n that is coupled to a mixing manifold 34 a, b . . . n which allows water from the discharge line 30 to mix with additives such as foams, compressed gas, and air from various sources before finally being discharged through a fire hose 36 a, b , . . . n terminating in a nozzle 38 .
More specifically, the additives may include a Class A foam concentrate suitable for fighting wildfires and structural fires, and a Class B foam concentrate for extinguishing flammable liquid fires. In the illustrated embodiment, the Class A foam concentrate is stored in a first foam tank 40 and pumped by a first foam pump 42 into a first foam manifold 44 that accommodates a first set of foam conduits 46 a, b . . . n leading to the mixing manifolds 34 a, b . . . n. A first foam valve 47 is provided in each conduit 46 a, b . . . n for controlling the amount of class A foam dispensed into the associated mixing manifold 34 a, b . . . n. Similarly, the Class B foam concentrate is stored in a second foam tank 48 and pumped by a second foam pump 50 into a second foam manifold 52 that accommodates a second set of foam conduits 54 a, b . . . n leading to the mixing manifolds 34 a, b . . . n. A second foam valve 55 is provided in each conduit 54 a, b . . . n for controlling the amount of class B foam dispensed into the associated mixing manifold 34 a, b . . . n.
The system also includes an air compressor 58 driven by a water motor or hydraulic turbine 66 in the discharge line of the main centrifugal pump 14 . The compressor 58 receives ambient air through an air cleaner 68 , compresses it, and injects the pressurized air into a gas manifold 56 , which is coupled to the mixing manifolds 34 a, b . . . n via gas conduits 62 a, b, n. The flow of this compressed air, which may be used to resuscitate firefighters or others overcome by smoke inhalation, is regulated by an air control valve 70 in an air conduit 85 leading to the gas manifold 56 .
In addition, the system includes a pressurized gas tank 60 for delivering an inert or chemical fire-extinguishing gas to the gas manifold 56 . A gas flow valve 63 is provided for regulating the flow between the gas tank 60 and the gas manifold 56 . Each mixing manifold 34 a, b . . . n preferably contains a set of mixing plates (not shown), including a first mixing plate positioned downstream of the conduits, 46 a, b . . . n, and 54 a, b . . . n leading from the foam tanks 40 , 48 , and a second mixing plate positioned downstream of the gas conduits 62 a, b . . . n. The purpose of these plates is to induce turbulence in the water flowing through the manifolds 34 a, b . . . n, thus allowing more efficient mixing than would be possible with purely laminar flow.
The control system 10 of the present system comprises a system of valves for regulating flow though the various supply and discharge lines so that the pressure of the fluid or fluids discharged from the nozzle 38 remains safe at all times, regardless of fluctuations in intake pressure, engine rpm, and various other factors. On the intake side of the pump 14 , the system includes a first control valve A located between the intake manifold 21 and the tank inlet opening 24 , a second control valve B located between the intake manifold and the fire hydrant 22 , and a third control valve C located between the tank outlet opening 27 and the supply line inlet opening 28 . On the discharge side of the pump 14 , the system includes a pressure relief valve D located in the discharge line 30 of the pump 14 , and a discharge valve E associated with the nozzle 42 , as well as the foam and gas control valves 47 , 55 , and 63 mentioned earlier.
The control system 10 also provides continuous monitoring of parameters such as flow and pressure at various points throughout the system. Specifically, flow monitoring is achieved by a liquid flow meter 72 located in the fire hose 36 . Pressure is monitored by transducers 74 , 76 , 78 , 79 , 80 , 82 , and 84 on or in the intake manifold 21 , discharge line 30 , hose 32 , compressor outlet line 85 , gas tank 60 , and foam lines 86 and 87 , respectively. The level of liquid in the water tank 18 and foam in foam tanks 40 and 48 is monitored by level sensors 88 , 90 , and 92 , respectively. Also included, although not illustrated, are various sensors and/or meters for monitoring conditions such as engine speed, voltage, current, temperature, and so forth.
Signals from the monitoring devices 72 , 74 , 76 , 78 , 80 , 82 , 84 , 88 , 90 , 92 , and others are input to a master processor 94 , which in turn outputs to the pump governor 96 , engine control module 96 , generator 98 , foam pump motors 99 , 101 , control and warning displays 100 , 102 , pump switches 104 , and drivers 106 , 108 for the various valves as shown in FIG. 2 . In addition, the master processor 94 sends and receives signals from one or both of a transmitter 110 that allows the discharge valve E to be operated remotely and a nozzle control module 112 that allows manual control by a firefighter carrying the hose. It also monitors voltage and current outputs from the generator 98 (which may be powered either by its own separate engine, not shown, or by power takeoff from the main engine 12 ), and sends information about these outputs to the vehicle warning and/or display systems 100 , 102 .
The master processor 94 also includes a recording system (not shown) for recording all the operations of the vehicle and its systems. The system may be queried after an incident for details about the operating times and functions of various components.
Sequential operation of various valves and other components of the system will now be described with continued reference to FIGS. 1 and 2 , as well as additional reference to FIGS. 3 a - i . Initially, all the valves in the system are closed, the water level in the tank 18 is at a preset level L between full and ¾ths full, and the primary pump 14 is off. At time t 1 , the primary pump 14 is switched on, the tank outlet valve C is opened, and the pump discharge pressure transducer 76 begins to monitor the discharge pressure of the pump. If the transducer 76 detects that the actual discharge pressure P A is below a preset minimum value P MIN , a small electric motor 114 driving a secondary (priming) pump 116 is switched on, and remains in operation until time t 2 , when P MIN is reached. At this point, the priming pump 116 switches off. Valve C stays open, and valves A and B stay closed until t 3 , when the pump discharge pressure transducer 76 detects that a preset desired output pressure P D (typically somewhere between 100 and 150 psi) has been reached, signifying that the nozzle discharge valve E can be opened, and the firefighters may begin spraying at the fire. In addition, the rate of flow F A is monitored by the flow meter 72 , and maintained at an optimum flow rate F OP .
If there is no fire hydrant or pressurized water source available at this point, the system continues to operate in this fashion until the water tank 18 is empty. However, if a pressurized source 20 is available, valves A and B are opened and valve C is closed as soon as P A =P D , allowing water from the pressurized source 20 to flow into the water tank 18 . At t 4 , when the level sensor 86 associated with the water tank 18 detects that the water level has returned to its initial value L, valve A closes so that all the water from the pressurized source 20 flows directly into the pump 14 .
After t 4 , the system is maintained more or less at steady state by the pressure governor 96 , which reacts to changes in the discharge pressure P A by actuating the pressure relief valve D and varying the RPM of the engine 12 . Operation of the governor 96 is described in greater detail in U.S. Pat. Nos. 3,786,869 and 4,189,005 to McLoughlin, as well as U.S. Pat. No. 5,888,052 to McLoughlin et al., the contents of all of which are incorporated by reference herein.
In most situations, the operation of the governor 96 is sufficient to keep the system running safely and smoothly, and to maintain the discharge pressure and flow rates within their desired ranges. One exception, however, is when the intake pressure suddenly drops to a very low level, such as when the fire hydrant runs out of water, or when the hose between the hydrant and the pump is run over or develops a leak, or is damaged in some other way. This can cause cavitation of the pump, and may endanger the firefighters on the hose lines. Accordingly, the system includes an intake pressure control mode that is activated whenever the pressure sensed by the intake pressure transducer 74 falls below a preset level P LOW (typically somewhere between 2 psi and 7 psi), as shown at t 5 in FIG. 3 i . When this occurs, the tank discharge valve C reopens, thus increasing the intake pressure by an amount proportional to the level of water in the tank. If, when the discharge valve C closes again at t 6 , the level of water in the water tank L is below the preset level L, then the hydrant-to-tank valve A opens as shown at t 6 in FIG. 3 a , and remains open until the desired water level L is reached, as shown at t 7 in FIG. 3 e.
The graphs shown in FIGS. 3 a - e have been greatly simplified for purposes of illustration. For instance, Valves A, B, C, and E, have all been shown to have only two states—fully open and fully closed. In reality, more complex valves having partially open and closed positions could also be used, in which case the changes in system pressure and flow would be more gradual than those shown here, but the basic principles of the invention would remain the same.
Various modifications and variations to the embodiments herein chosen for purposes of illustration will readily occur to those skilled in the art. To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope of thereof, which is assessed only be a fair interpretation of the following claims.
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A control system for a pumping apparatus consisting of an engine-driven primary pump includes an intake pressure regulating system for maintaining the intake pressure above a preset low value, a discharge pressure regulating system for maintaining the discharge pressure below a preset maximum value, and a master controller for monitoring, recording, and controlling the intake and discharge pressure regulating systems and other components of the system. The discharge pressure regulating system includes a pump governor which varies the engine RPM and operates a relief valve in response to fluctuations in discharge pressure. The intake pressure regulating system includes a reserve tank that is automatically maintained at a preset level which determines the minimum intake pressure of the system. The system may also include a priming pump, foam tanks, foam pumps, bottled nonflammable gas, and an air compressor.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of priority of German Patent Application No. 10 2010 032 964.9, filed Jul. 30, 2010, pursuant to 35 U.S.C. 119(a)-(d), the disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
The present disclosure relates to an apparatus for the warming or heating of plastics material pre-forms and, more particularly, an apparatus for heating plastics material pre-forms with sterile room.
BACKGROUND
So-called blow moulding machines, which shape plastics material pre-forms into plastics material containers by acting upon them with compressed air, are known from the prior art. For this purpose the plastics material pre-forms to be shaped are introduced into these blow moulding machines and are expanded there. As a rule the plastics material pre-forms are heated before entering the blow moulding machine in order to be expanded in the heated or soft state in this way. To this end, heating devices or furnaces, through which the plastics material pre-form passes and which heat the plastics material pre-forms during this passage through, are known from the prior art.
So-called sterile applications in which the plastics material containers are filled under sterile conditions are also known from the prior art. For this purpose, the containers are sterilized on the inside and the outside in the usual way before the filling and they are conveyed through a clean room or sterile room during this passage through. These sterilization processes, however, are frequently relatively complicated.
It may therefore be desirable, in the case of containers to be treated in a sterile manner, to simplify the production thereof.
SUMMARY
According to various aspects of the disclosure, an apparatus for the heating of plastics material pre-forms has a conveying device which conveys the plastics material pre-forms along a pre-determined conveying path. In addition, at least one heating device is provided which heats the plastics material pre-forms during the transportation thereof along the conveying path.
According to the disclosure, the conveying path of the plastics material pre-forms extends at least locally through a sterile room, this sterile room being separated from the environment by at least one and, in some aspects, a plurality of walls.
It is thus proposed to allow not only the stages of filling the containers to take place under sterile conditions, but also the heating of the plastics material pre-forms. In this way, it would be possible for the plastics material pre-forms to be sterilized before their entry into the heating device or even to be produced immediately before their entry into the heating device, and, in this way, they can be kept sterile.
In some aspects, it may be desirable for at least one wall forming the sterile room to be made movable. It is thus possible for a wall of the sterile room to be moved jointly with the plastics material pre-forms. In this way, sterile rooms which are relatively small spatially and which are accordingly relatively simple to keep sterile can be formed. It would also be possible, however, for a sterile room to be made stationary and for example to surround the entire heating device.
It may also be advantageous for at least one wall separating the sterile room to be made stationary. The plastics material pre-forms for example can be supplied to the heating device by way of this stationary wall.
In the case of an exemplary embodiment, the conveying device has a rotatable carrier on which at least one holding element for holding the plastics material pre-forms is arranged. In this way, in a manner similar to filling or blow moulding machines, the heating device can be designed with a heating wheel on which at least one and, in some aspects, a plurality of holding elements are arranged by which the plastics material pre-forms are conveyed. In this case it may be advantageous—as mentioned above—for at least one wall of the aforesaid sterile room to be moved jointly with these heating elements. With this movement, therefore, the containers are moved along a circular or circular-segmental path. In this case it may be advantageous if that wall of the sterile room which is situated radially on the inside with respect to the containers is arranged so as to be movable and if that wall which is situated radially on the outside with respect to the containers to be heated is arranged so as to be stationary. In this case the conveying device advances the containers separately.
In the case of an exemplary embodiment the heating device has at least one microwave generation device. The embodiment by means of a sterile room, as described here, may be suitable in particular for heating the plastics material pre-forms by means of microwave heating devices, since in the case of heating devices of this type a considerable part of these heating devices in terms of space can be arranged at a distance from the plastics material pre-form to be heated.
It is pointed out, however, that the heating device can also be an infrared furnace. In addition, combinations of infrared and microwave heating elements would also be possible, for example in such a way that a pre-heating by infrared heating elements and a subsequent heating by microwave heating elements are carried out.
In the case of an exemplary embodiment at least one holding element for the plastics material pre-forms has a mandrel capable of being introduced into the aperture of the plastics material pre-forms. With this embodiment, therefore, the containers are guided on the inside at the apertures thereof. It would also be possible, however, for the containers to be guided on the carrier ring thereof by means of clamps for example. It may be advantageous for the plastics material pre-forms to be conveyed in such a way the apertures thereof are not heated. In this way, it is possible, for example, for the plastics material pre-forms to be inserted from above into a microwave heating device or a resonator respectively and to be heated there.
In the case of an exemplary embodiment the apparatus has a sealing device which is arranged between at least one movable wall and a stationary wall of the sterile room. As a result of this procedure it is possible for the sterile room to be sealed off from its surroundings. In this case the sealing device used can be in the form of a so-called surge tank for example, which has an annular duct which is filled with liquid and which is arranged so as to be stationary for example and in which an element of the movable wall slides in such a way that air or a gas cannot penetrate from the sterile room to the outside.
In the case of an exemplary embodiment the sterile room is designed in the manner of a duct around the conveying path of the plastics material pre-forms. In this way, as mentioned above, the volume of the sterile room can be kept small. This sterile room can thus be designed in the manner of a hose or even in the form of a ring or torus in the case of a circular movement about the conveying path of the plastics material pre-forms.
In the case of an exemplary embodiment at least one heating device is arranged at least in part outside the sterile room. If a microwave heating device is used for example, the magnetron of this microwave heating device could be arranged outside the sterile room, the wave guide could be introduced into the sterile room and the resonator could be arranged in the interior of the sterile room.
It may be advantageous for the apparatus to have at least one drive for rotating the plastics material pre-forms about the longitudinal axis thereof. In addition, it may be advantageous for a driving device to be provided which also moves the plastics material pre-forms in a direction at a right angle to their conveying path, for example in order to introduce them into a resonator of the heating device.
In addition, the present disclosure relates to a plant for shaping plastics material pre-forms into plastics material containers with an apparatus of the type described above, as well as a shaping device for shaping the plastics material pre-forms into plastics material containers which is arranged in a conveying device of the plastics material containers downstream of the apparatus. It may be advantageous for the shaping device to have a sterile room, inside which the plastics material containers are conveyed during the shaping procedure and for this sterile room to be attached—at least indirectly and in some aspects by way of a further sterile room—to the sterile room of the apparatus for heating the plastics material pre-forms.
This can ensure that contamination of the plastics material pre-forms no longer occurs between the heating device and the shaping device. In this way, it would be possible for the heating device and the shaping device to be arranged in a common casing or sterile room, but it would also be possible for the two sterile rooms to be separate from each other and for the plastics material pre-forms to be transferred from one sterile room into the other sterile room without contact with the surroundings, for example by way of conveying star wheels or switching devices.
In the case of an exemplary embodiment a further sterilization device for sterilizing the (heated) plastics material pre-forms is arranged between the heating device for the plastics material pre-forms and the shaping device.
In addition, the present disclosure relates to a method of shaping plastics material pre-forms into plastics material containers, in which plastics material pre-forms are conveyed along a pre-set conveying path through a heating device and are heated during this transportation and following the heating they are shaped by a shaping device to form plastics material containers. According to the disclosure, during the heating the plastics material containers are conveyed at least at a distance through a sterile room. It is thus also proposed with respect to the method that the plastics material pre-forms should be guided through a sterile room while they are being heated.
It may be advantageous for the apparatus specified above to have a sterilization device for sterilizing the plastics material pre-forms. In this case the sterilization of these plastics material pre-forms is carried out during the heating thereof. Nozzle devices for example would be used in this case, but it would also be possible for emitters for electron radiation to be used.
In the case of exemplary embodiment the apparatus has a cleaning device in order to clean the apparatus itself. In this case, for example, nozzles can be provided which act upon wall regions of the sterile room with a sterilizing medium. It is possible both for nozzles of this type to be arranged on the movable walls, in order to clean the stationary walls or stationary elements in general, and nozzles which are arranged on the stationary walls or on stationary elements of the apparatus and which clean the walls which are movable in each case. In this way, a so-called CIP cleaning (cleaning in place) of the apparatus is possible.
Further exemplary embodiments and advantages may be evident from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 shows an exemplary plant according to various aspects of the disclosure for the treatment of containers;
FIG. 2 is a detailed illustration of an exemplary apparatus according to various aspects of the disclosure;
FIG. 3 is a further detailed illustration of an exemplary apparatus according to various aspects of the disclosure; and
FIG. 4 is a further illustration of an exemplary heating device.
DETAILED DESCRIPTION
FIG. 1 is a diagrammatic illustration of an exemplary plant 100 according to the disclosure for the treatment of containers. In this case plastics material pre-forms 10 are supplied by way of a supply wheel 18 to an apparatus designated 1 in its entirety for the heating of plastics material pre-forms. This apparatus 1 for the heating of plastics material pre-forms has a carrier 32 which is rotatable as shown by the arrow P 1 and on which a plurality (not shown) of heating devices for heating plastics material pre-forms are arranged. In this case the carrier 32 is thus a component part of a conveying device designated 2 in its entirety for conveying the plastics material pre-forms.
In this case the containers are moved on the carrier 32 along a conveying path P, i.e. along a circular conveying path P here. The reference number 12 relates to a sterile room which is illustrated only diagrammatically and inside which the containers are conveyed during the complete heating procedure. This sterile room 12 is bounded in this case by an inner wall 22 and an outer wall 24 . In this way, the volume of the sterile room 12 can be kept relatively small as compared to the entire size of the apparatus 1 . In this case the sterile room 12 thus has an annular (segmental) cross-section.
Following the heating, the plastics material pre-forms are transferred to a blow moulding machine 50 by way of a transfer wheel 62 . The reference number 64 designates an ejection device which separates out defective pre-forms or incorrectly heated pre-forms. The blow moulding machine has in turn a blowing wheel 56 with a plurality of blowing stations 55 arranged in it. Inside these blowing stations 55 the plastics material pre-forms are expanded to form plastics material containers. In addition, the blow moulding machine 50 in this case forms an annular sterile room 52 which in turn is bounded by a stationary wall 58 and a movable wall 59 . The reference number 63 designates a further sterile room in which the containers are conveyed during the transfer from the apparatus 1 to the blow moulding machine 50 .
The blow moulding machine 50 is followed by a removal device 72 , by way of which the plastics material containers are removed. In this case this removal device 72 too has a conveying star wheel 74 as well as an ejection device which in turn is used to separate out defectively formed containers 20 . This blow moulding machine can have attached to it for example a filling machine which fills with a liquid the containers which have now been produced.
The reference number 30 designates a sterilization device which sterilizes the plastics material pre-forms entering the apparatus 1 , for example by acting upon them with a sterilizing medium. In this case this sterilization device 30 can be designed so as to be movable, i.e. to move jointly with the containers, or it can also be stationary.
FIG. 2 is a detailed illustration of an exemplary apparatus 1 according to the disclosure. In this case a holding element 45 is provided which enters into an aperture of the plastics material pre-forms 10 and holds and conveys them in this way. The reference number 44 designates a drive which causes a rotation of the plastics material pre-forms 10 about the longitudinal axis thereof. In addition, a lifting and/or lowering movement of the plastics material pre-form 10 along the arrow P 2 can be achieved by means of the drive 44 . The reference number 16 designates roughly diagrammatically a folding bellows which is used for sealing off this lifting movement, so that the lifting movement can also take place inside the sterile room 12 .
The reference number 4 designates in its entirety the heating device for heating the plastics material pre-forms.
FIG. 3 is a further illustration of the apparatus shown in FIG. 2 . Here, as also in FIG. 2 , the sterile room 12 is shown which in this case is formed by a stationary outer wall 24 and a movable wall 22 . The reference number 25 designates roughly diagrammatically a sealing device for sealing off the movement of the movable wall 22 with respect to the stationary wall 24 . This can be, as mentioned above, a so-called surge tank. The reference number 27 designates a lower wall which bounds the sterile room 12 at the bottom and the reference number 28 designates an upper wall which bounds the sterile room 12 at the top.
In this case the lower wall 27 and the upper wall 28 are preferably movable, i.e. they rotate jointly with the containers. In addition, a sealing device (not shown) can be provided between the upper wall 28 and the outer (stationary) wall 24 . In this case the lower wall 27 and the upper wall 28 can be formed in one piece with the inner movable wall 22 . In addition, a supply device (not shown) can also be provided, which introduces a sterile medium such as for example sterile air into the sterile room 12 , in which case it may be advantageous for the pressure of the sterile medium inside the sterile room 12 to be kept higher than a surrounding pressure in the surroundings U outside the sterile room 12 .
The reference number 84 designates a component part of the heating device, such as for example a magnetron, which generates microwaves. The reference number 86 designates a waveguide which guides the microwaves to a resonator 42 by way of a further waveguide 38 . The plastic preforms are heated by being acted upon with microwave within the resonator 42 . The reference number 26 designates closure caps for closing off the resonator 42 at the top and bottom for cleaning purposes.
FIG. 4 is a further illustration of the heating device. Here, in particular, a cleaning of the resonator 42 is illustrated. In this case a cleaning medium, which is kept available in a reservoir 82 , can be introduced through the waveguide 86 , 38 . The reference number 87 designates tuning elements for tuning the resonator or the microwave power, for example so-called tuning pins which are capable of being introduced into the waveguide 38 .
The reference number 88 designates a sensor device which may advantageously set a heating of the plastics material pre-forms without contact.
The embodiments shown in FIGS. 3 and 4 thus permit a so-called CIP cleaning (cleaning in place) of the respective resonators 42 .
It will be apparent to those skilled in the art that various modifications and variations can be made to the apparatus for the heating of plastics material pre-forms with sterile room of the present disclosure without departing from the scope of the invention. Throughout the disclosure, use of the terms “a,” “an,” and “the” may include one or more of the elements to which they refer. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only.
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An apparatus for the heating of plastics material pre-forms includes a conveying device, which conveys the plastics material pre-forms along a pre-determined conveying path, and at least one heating device, which heats the plastics material pre-forms during the transportation thereof. The conveying path of the plastics material pre-forms extends at least locally through a sterile room, wherein the sterile room is separated from the environment by a plurality of walls.
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TECHNICAL FIELD
[0001] The present invention relates to a steel wire material and a method for manufacturing the same, and relates more specifically to a steel wire material (“steel wire material” is hereinafter simply referred to as “wire material”) for mechanical descaling formed with a scale easily removable by mechanical descaling and a method for manufacturing the same.
BACKGROUND ART
[0002] A scale is formed normally on the surface of a wire material manufactured by hot rolling, and it is required to remove the scale before subjecting the wire material to secondary work such as drawing and the like. As such a scale removing method before secondary work, a batch type acid cleaning method was employed in prior arts, however, in recent years, from the viewpoints of the environmental pollution and cost reduction, a mechanical descaling (hereinafter referred to as MD) method has come to be employed. Therefore, the wire material is required to be formed with a scale with excellent MD performance.
[0003] As methods for manufacturing a wire material formed with a scale with excellent MD performance, Patent Literatures 1-4 can be cited for example. In Patent Literatures 1, 2, the scale amount remaining in the wire material after MD is reduced by forming a scale high in FeO ratio (or low in Fe 3 O 4 ratio) and thick. In Patent Literature 3, by lowering the boundary face roughness, propagation of the crack occurring on the boundary face of the scale is promoted, and the remaining scale amount is reduced. In Patent Literature 4, by making the holes of 1 μm or more and 3 μm or less present by a constant amount in the scale, the scale adhesiveness is increased, and the peeling performance is improved.
[0004] However, Patent Literatures 1-4 described above have problems as described below. According to the method of forming the scale thick as Patent Literatures 1, 2, even when a bending strain is applied to the wire material by the MD method and the wire material surface is subjected to brushing, it is difficult to perfectly remove the scale. More specifically, according to the MD method, different from the batch type acid cleaning method, it is difficult to remove the entire scale evenly and stably, and even when the wire material formed with thick scale is subjected to MD, the surface of the wire material may occasionally be spotted with finely crushed scale powder. When the remaining scale remaining locally thus increases, in the secondary work such as drawing and the like, problems such as occurrence of a flaw due to the defective lubrication, lowering of the lifetime of the dice and the like are caused.
[0005] Also, it is difficult to stably lower the boundary face roughness by the method of lowering the boundary face roughness such as Patent Literature 3, it is difficult to stably form the holes even by the method of forming large holes of 1 μm or more inside the scale such as Patent Literature 4, and it is difficult to stably reduce the remaining scale amount according to either of these technologies.
CITATION LIST
Patent Literature
[0000]
[Patent Literature 1] Japanese Unexamined Patent Application Publication No. H4-293721
[Patent Literature 2] Japanese Unexamined Patent Application Publication No. H11-172332
[Patent Literature 3] Japanese Unexamined Patent Application Publication No. H8-295992
[Patent Literature 4] Japanese Patent No. 3544804
SUMMARY OF INVENTION
Technical Problems
[0010] The present invention has been developed in view of the circumstances described above, and its object is to provide a wire material having a scale capable of easily peeling off by MD and a method for manufacturing the same.
Solution to Problems
[0011] The steel wire material of the present invention which solved the problems described above is a steel wire material containing C: 0.05-1.2% (“%” means “% by mass”, the same hereinafter for chemical components), Si: 0.01-0.7%, Mn: 0.1-1.5%, P: 0.02% or less (not including 0%), S: 0.02% or less (not including 0%), and N: 0.005% or less (not including 0%), with the remainder being iron and unavoidable impurities, in which a scale with 6.0 inn or more and 20 μm or less thickness is included, and holes of an equivalent circle diameter of 1 μm or less in the scale occupy 10% or less by area.
[0012] According to the necessity, the steel wire material of the present invention may also contain (a) Cr: 0.3% or less (not including 0%) and/or Ni: 0.3% or less (not including 0%), (b) Cu: 0.3% or less (not including 0%), (c) at least one element selected from a group consisting of Nb, V, Ti, Hf and Zr by 0.1% or less (not including 0%) in total, (d) Al: 0.1% or less (not including 0%), (e) B: 0.005% or less (not including 0%), and (f) Ca: 0.01% or less (not including 0%) and/or Mg: 0.01% or less (not including 0%).
[0013] Further, the present invention also includes a method for manufacturing a steel wire material including the steps of hot rolling steel of any one of the chemical compositions described above at 1,000-1,100° C. of rolling finish temperature, cooling at a rate achieving 0.20-20 sec. of the holding time of 950° C. or above and less than 0.15 sec. of the holding time of 950° C. or below by bringing a non-oxygen medium into contact with the hot rolled steel, and thereafter winding at 750-950° C. In the method for manufacturing, it is preferable that the non-oxygen medium is inert gas or water, and it is further preferable that the inert gas is nitrogen.
Advantageous Effects of Invention
[0014] In the steel wire material of the present invention, the thickness of the scale is adjusted to a predetermined range, and the fine holes inside the scale are suppressed. Thus, since the scale easily peels off at the time of MD, sufficient peeling performance can be secured with a simple descaling device, adverse effects (a flaw on the surface of the wire material, defective lubrication and the like due to leaving the scale unremoved) are not exerted in secondary work such as drawing and the like, and the steel wire material of high quality can be provided. Also, because the scale loss is less, high yield can be maintained.
DESCRIPTION OF EMBODIMENTS
[0015] With respect to the wire material, the scale is removed by MD before executing secondary work such as drawing and the like, and the lifetime of the dice is shortened when the scale remains after MD. Therefore, the wire material having a scale easily peeling off at the time of MD has been desired.
[0016] The MD method is a method for making the scale peel off by applying strain to the wire material to generate cracks inside the scale or in the boundary face of the base iron and the scale. Conventionally, increase of the FeO ratio inside the scale has been executed in order to improve the peeling performance of the scale. This is because the increase of the FeO ratio inside the scale is considered to be effective in improving the peeling performance of the scale at the time of MD because the strength of FeO is weaker than Fe 2 O 3 and Fe 3 O 4 . In order to increase the FeO ratio inside the scale, it is usually necessary to form the scale (secondary scale formed in or after descaling before finish rolling) at a high temperature, however, when the scale is formed at a high temperature, fine holes (1 μm or less in terms of the equivalent circle diameter) are liable to be generated, these fine holes are liable to cohere to each other, and a row of holes is liable to be formed inside the scale. When such a row of holes is formed, only a part of the scale layer peels off at the time of MD, and the scale remains on the surface of the wire material.
[0017] So, as a result of studies by the present inventors, it was found out that formation of the fine holes could be suppressed while securing the thickness of the scale when oxygen from the atmosphere was blocked immediately after hot rolling (finish rolling), more specifically the wire material was made into contact with the non-oxygen medium and was cooled until the start of winding, and the residence time on the high temperature side was extended and the residence time on the low temperature side was shortened in cooling by the non-oxygen medium.
[0018] The thickness of the scale is to be 6 μm or more in order to secure the MD performance. The scale thickness is preferably 7 μm or more, more preferably 8 μm or more (particularly 9 μm or more). On the other hand, when the scale thickness exceeds 20 μm, the scale loss increases and the yield drops. Also, in the cooling step and transportation and conveying, the scale peels off and the rust is generated. The scale thickness is preferably 19 μm or less, more preferably 18 μm or less.
[0019] Further, the fine holes inside the scale which are the holes of 1 μm or less size in terms of the circle equivalent diameter are to be 10% or less by area. When the fine holes exceeds 10% by area, the fine holes cohere to each other inside the scale, peeling occurs only in the portion at the time of MD, and the scale remains on the surface of the wire material. The area ratio of the fine holes is preferably 9% or less, more preferably 8% or less (particularly 7% or less). Normally, the lower limit of the size of the fine holes of the object of the present invention is approximately 0.1 μm.
[0020] By making the thickness of the scale and the area ratio of the fine holes as described above, the remaining scale amount after MD can be made 30% or less by the area ratio relative to the scale amount before MD. This is equivalent to approximately 0.05 mass % or less in terms of the remaining scale amount relative to the mass of the steel wire material. The remaining scale amount is preferably 25% or less by area, more preferably 20% or less by area.
[0021] In order to obtain the scale with the properties described above (the scale thickness and the area ratio of the fine holes), it is important to adjust the rolling-completing temperature (finish rolling temperature) and the cooling condition (the ambient atmosphere and the cooling time) after the finish rolling.
[0022] The rolling-completing temperature is to be 1,000-1,100° C. When the rolling-completing temperature exceeds 1,100° C., the scale loss increases. On the other hand, when the rolling-completing temperature is below 1,000° C., the scale thickness cannot be secured. The rolling-completing temperature is preferably 1,020-1,080° C.
[0023] After the finish rolling, the wire material is made into contact with the non-oxygen medium immediately, oxygen is blocked, and generation of the fine holes inside the scale which grow after the finish rolling is suppressed. It is preferable that the non-oxygen medium is an inert gas or water. Also, it is preferable that the inert gas is nitrogen gas.
[0024] In cooling when the wire material is made into contact with the non-oxygen medium, the holding time at a high temperature range (high temperature residence time) is secured for a predetermined time or more, and the holding time at a low temperature range (low temperature residence time) is shortened. More specifically, the wire material is cooled at a rate the holding time at 950° C. or above becomes 0.20-20 sec. and the holding time at 950° C. or below until start of winding becomes less than 0.15 sec. By extending the high temperature residence time at 950° C. or above, growth of the scale can be promoted. Also, when the low temperature residence time at 950° C. or below until the start of the winding becomes 0.15 sec. or more, concentrating at the boundary face of the alloy elements such as Si, Mn, Cr and the like becomes conspicuous, propagation of Fe is impeded, and the scale hardly grows. The high temperature residence time is preferably 0.3-15 s, and the low temperature residence time is preferably 0.13 sec. or less.
[0025] The high temperature residence time and the low temperature residence time can be adjusted by adjusting the water volume ratio in each temperature range in water cooling, and by adjusting the gas flow rate ratio in each temperature range when the inert gas is used. In both cases, the water volume or the gas flow rate in the high temperature range can be reduced than that in the low temperature range.
[0026] After cooling by the non-oxygen medium has been completed, the wire material is wound up at 750-950° C. By making the winding temperature such range, the scale thickness can be adjusted to a desired range. The winding temperature is preferably 760-940° C., more preferably 780-930° C.
[0027] Below, the chemical composition of the steel wire material of the present invention will be described.
C: 0.05-1.2%
[0028] C is an element greatly affecting the mechanical properties of steel. In order to secure the strength of the wire material, the C amount was stipulated to be 0.05% or more. The C amount is preferably 0.15% or more, more preferably 0.3% or more. On the other hand, when the C amount is excessively high, the hot workability in manufacturing the wire material deteriorates. Therefore, the C amount was stipulated to be 1.2% or less. The C amount is preferably 1.0% or less, more preferably 0.9% or less.
Si: 0.01-0.7%
[0029] Si is an element required for deoxidizing steel. When its content is too low, formation of Fe 2 SiO 4 (fayalite) becomes insufficient, and the MD performance deteriorates. Therefore, the Si amount was stipulated to be 0.01% or more. The Si amount is preferably 0.1% or more, more preferably 0.2% or more. On the other hand, when the Si amount is excessively high, by excessive formation of Fe 2 SiO 4 (fayalite), such problems occur that the MD performance extremely deteriorates, a surface decarburized layer is formed, and the like. Therefore, the Si amount was stipulated to be 0.7% or less. The Si amount is preferably 0.5% or less, more preferably 0.4% or less.
Mn: 0.1-1.5%
[0030] Mn is an element useful in securing the quenchability of steel and increasing the strength. In order to effectively exert such actions, the Mn amount was stipulated to be 0.1% or more. The Mn amount is preferably 0.2% or more, more preferably 0.4% or more. On the other hand, when the Mn amount is excessively high, segregation occurs in the cooling step after the hot rolling, and super-cooled structure (martensite and the like) harmful for the drawability and the like is liable to be generated. Therefore, the Mn amount was stipulated to be 1.5% or less. The Mn amount is preferably 1.4% or less, more preferably 1.2% or less.
P: 0.02% or Less (not Including 0%)
[0031] P is an element deteriorating the toughness and ductility of steel. In order to prevent the wire breakage in the drawing step and the like, the P amount was stipulated to be 0.02% or less. The P amount is preferably 0.01% or less, more preferably 0.005% or less. Although the lower limit of the P amount is not particularly limited, it is approximately 0.001% normally.
S: 0.02% or Less (not Including 0%)
[0032] Similarly to P, S is an element deteriorating the toughness and ductility of steel. In order to prevent the wire breakage in the drawing step and the twisting step thereafter, the S amount was stipulated to be 0.02% or less. The S amount is preferably 0.01% or less, more preferably 0.005% or less. Although the lower limit of the S amount is not particularly limited, it is approximately 0.001% normally.
N: 0.005% Or Less (not Including 0%)
[0033] N is an element deteriorating the ductility of steel when the content thereof becomes excessively high. Therefore, the N amount was stipulated to be 0.005% or less. The N amount is preferably 0.004% or less, more preferably 0.003% or less. Although the lower limit of the N amount is not particularly limited, it is approximately 0.001% normally.
[0034] The fundamental composition of the steel wire material of the present invention is as described above, and the balance is substantially iron. However, inclusion of unavoidable impurities brought in due to situations of raw materials, materials, manufacturing facilities and the like in the steel wire material is allowed as a matter of course. Further, it is also recommended to add elements described below according to the necessity within a range not impeding the actions and effects of the present invention.
[0000] Cr: 0.3% or Less (not Including 0%) and/or Ni: 0.3% or Less (not Including 0%)
[0035] Both of Cr and Ni are elements enhancing the quenchability of steel and contributing to increase the strength. In order to exert such actions effectively, both of the Cr amount and Ni amount are preferably 0.05% or more, more preferably 0.10% or more, and further more preferably 0.12% or more. On the other hand, when the Cr amount and Ni amount are excessively high, the martensite structure is liable to be generated, adhesiveness of the scale to the base iron increases excessively, and the peeling performance of the scale at the time of MD deteriorates. Therefore, both of the Cr amount and Ni amount are preferably 0.3% or less, more preferably 0.25% or less, and further more preferably 0.20% or less. Cr and Ni may be added respectively and independently or may be added simultaneously.
Cu: 0.3% or Less (not Including 0%)
[0036] Cu is an element having an action of promoting peeling of the scale. In order to exert such action effectively, the Cu amount is preferably 0.01% or more, more preferably 0.05% or more, and further more preferably 0.07% or more. On the other hand, when the Cu amount is excessively high, peeling of the scale is promoted excessively, the scale peels off during rolling, other scales which are thin and highly adhesive are generated on the peeled surface, and the rust is generated when the wire material coil is stored and transported. Therefore, the Cu amount is preferably 0.3% or less, more preferably 0.25% or less, and further more preferably 0.20% or less.
[0037] At least one element selected from a group consisting of Nb, V, Ti, Hf and Zr: 0.1% or less (not including 0%) in total
[0038] All of Nb, V, Ti, Hf and Zr are elements forming fine carbonitride and contributing to increase the strength. In order to exert such actions effectively, all of the Nb amount, V amount, Ti amount, Hf amount and Zr amount are preferably 0.003% or more, more preferably 0.007% or more, and further more preferably 0.01% or more. On the other hand, when these elements are excessively high, the ductility deteriorates, and therefore the total amount thereof is preferably 0.1% or less, more preferably 0.08% or less, and further more preferably 0.06% or less. These elements may be added respectively and independently or two elements or more may be added in combination.
Al: 0.1% or Less (not Including 0%)
[0039] Al is an element effective as a deoxidizing agent. In order to exert such action effectively, the Al amount is preferably 0.001% or more, more preferably 0.01% or more, and further more preferably 0.02% or more. On the other hand, when the Al amount is excessively high, oxide-based inclusions such as Al 2 O 3 and the like increase, and wire breakage frequently occurs in drawing work and the like. Therefore, the Al amount is preferably 0.1% or less, more preferably 0.08% or less, and further more preferably 0.06% or less.
B: 0.005% or Less (not Including 0%)
[0040] B is an element suppressing formation of ferrite by being present as free B (B that does not form the compound) solid-solved in steel, and is an element effective particularly in a high strength wire material which requires suppression of a longitudinal crack. In order to exert such actions effectively, the B amount is preferably 0.0001% or more, more preferably 0.0005% or more, and further more preferably 0.0009% or more. On the other hand, when the B amount is excessively high, the ductility deteriorates. Therefore, the B amount is preferably 0.005% or less, more preferably 0.0040% or less, and further more preferably 0.0035% or less.
[0000] Ca: 0.01% or Less (not Including 0%) and/or Mg: 0.01% or Less (not Including 0%)
[0041] Both of Ca and Mg are elements having an action of controlling the form of the inclusions and enhancing the ductility. Further, Ca also has an action of enhancing the corrosion resistance of the steel material. In order to exert such actions effectively, both of the Ca amount and the Mg amount are preferably 0.001% or more, more preferably 0.002% or more, and further more preferably 0.003% or more. On the other hand, when these elements are excessively high, the workability deteriorates. Therefore, both of the Ca amount and the Mg amount are preferably 0.01% or less, more preferably 0.008% or less, and further more preferably 0.005% or less. Ca and Mg may be added respectively and independently or may be added simultaneously.
Example
[0042] Below, the present invention will be explained more specifically referring to an example: The present invention is not limited by the example described below, and it is a matter of course that the present invention can also be implemented with modifications being added appropriately within the scope adaptable to the purposes described above and below, and any of them is to be included within the technical range of the present invention.
[0043] After steel of the chemical composition shown in Tables 1, 2 was smelted according to an ordinary smelting method, a billet of 150 mm×150 mm was manufactured and was heated inside a heating furnace. Thereafter, the primary scale formed inside the heating furnace was descaled using high-pressure water, hot rolling, cooling and winding were executed under the conditions shown in Table 3, and the steel wire material of Φ5.5 mm was obtained.
[0044] The obtained steel wire material was measured by a method described below.
(1) Measurement of Thickness of Scale
[0045] Samples with 10 mm length were taken from the front end, center part and rear end of the coil respectively, and the cross sections of the scale of optional three locations from each sample were observed using a scanning electron microscope (SEM) (observation magnification: 5,000 times). The scale thickness was measured for 10 points at every 100 μm length in the peripheral direction of the steel wire material on each measurement location, the average scale thickness thereof was obtained, and the average value of the three locations was made the scale thickness of each sample. Further, the average value of respective samples (the front end, center part and rear end of the coil) was calculated, and was made the scale thickness of each test No.
(2) Measurement of Area Ratio of Holes Inside Scale
[0046] Similarly to above (1), samples with 10 mm length were taken from the front end, center part and rear end of the coil respectively, the cross sections of the scale of optional three locations from each sample were observed using the SEM (measurement field of view: 25×20 μm, observation magnification: 5,000 times). The area ratio of the holes of the equivalent circle diameter of 1 μm or less was obtained on each measurement location, and the average value of the three locations was made the area ratio of fine (1 μm or less in terms of the equivalent circle diameter) holes of each sample. Further, the average value of respective samples (the front end, center part and rear end of the coil) was calculated, and was made the area ratio of the fine holes of each test No.
(3) Measurement of MD Performance
[0047] Samples with 250 mm length were taken from the front end, center part and rear end of the coil respectively, were applied with deformation strain of 6% by a tensile test machine, and were taken out from the chuck. Air was thereafter blown to the sample, and the scale on the surface of the steel wire material was blown out. The appearance before and after application of the strain was photographed by a digital camera, and the area ratio of the remaining scale was calculated by comparing the both by image analysis.
[0048] The results are shown in Tables 4, 5.
[0000]
TABLE 1
Chemical composition (mass %) with the remainder being iron and unavoidable impurities
Steel kind
C
Si
Mn
P
S
N
Cr
Ni
Cu
Al
B
Others
A-1
0.73
0.28
0.63
0.005
0.002
0.002
—
—
—
—
—
—
A-2
0.73
0.28
0.63
0.005
0.002
0.002
0.25
—
—
—
—
—
A-3
0.73
0.28
0.63
0.005
0.002
0.002
—
0.18
—
—
—
—
A-4
0.73
0.28
0.63
0.005
0.002
0.002
—
—
0.22
—
—
—
A-5
0.73
0.28
0.63
0.005
0.002
0.002
—
—
—
0.038
—
—
A-6
0.73
0.28
0.63
0.005
0.002
0.002
—
—
—
0.0005
—
A-7
0.73
0.28
0.63
0.005
0.002
0.002
—
—
—
—
—
Hf = 0.041
A-8
0.73
0.28
0.63
0.005
0.002
0.002
—
—
—
—
—
Mg = 0.008
A-9
0.73
0.28
0.63
0.005
0.002
0.002
—
—
—
—
—
Nb = 0.056
A-10
0.73
0.28
0.63
0.005
0.002
0.002
—
—
—
—
—
V = 0.082
A-11
0.73
0.28
0.63
0.005
0.002
0.002
—
—
—
—
—
Zr = 0.05
A-12
0.73
0.28
0.63
0.005
0.002
0.002
—
—
—
—
—
Ca = 0.002
A-13
0.73
0.28
0.63
0.005
0.002
0.002
—
—
—
—
—
Ti = 0.044
A-14
0.73
0.28
0.63
0.005
0.002
0.002
0.08
0.05
—
—
—
—
A-15
0.73
0.28
0.63
0.005
0.002
0.002
0.08
0.19
0.07
—
—
—
A-16
0.73
0.28
0.63
0.005
0.002
0.002
0.05
0.09
—
0.033
—
—
A-17
0.73
0.28
0.63
0.005
0.002
0.002
0.18
0.15
—
—
0.0022
—
A-18
0.73
0.28
0.63
0.005
0.002
0.002
0.12
0.15
—
—
—
Ti = 0.063
A-19
0.73
0.28
0.63
0.005
0.002
0.002
0.22
—
0.03
—
—
—
A-20
0.73
0.28
0.63
0.005
0.002
0.002
0.16
—
0.14
0.026
—
—
A-21
0.73
0.28
0.63
0.005
0.002
0.002
—
0.24
0.08
—
—
—
A-22
0.73
0.28
0.63
0.005
0.002
0.002
—
0.21
0.09
0.035
—
—
A-23
0.73
0.28
0.63
0.005
0.002
0.002
—
0.15
0.18
—
0.0009
—
A-24
0.73
0.28
0.63
0.005
0.002
0.002
—
0.05
0.16
—
—
Zr = 0.058
[0000]
TABLE 2
Chemical composition (mass %) with the remainder being iron and unavoidable impurities
Steel kind
C
Si
Mn
P
S
N
Cr
Ni
Cu
Al
B
Others
B
0.05
0.11
0.28
0.002
0.003
0.002
0.29
0.05
0.05
—
—
Ti = 0.045
C
0.19
0.27
0.42
0.003
0.001
0.002
—
—
0.08
0.036
—
—
D
0.52
0.43
0.86
0.002
0.003
0.002
—
0.15
—
0.022
—
Ca = 0.005
E
0.72
0.64
0.72
0.002
0.004
0.002
—
0.07
0.18
—
0.0005
Ti = 0.042, V = 0.038
F
0.91
0.39
1.15
0.002
0.003
0.002
0.14
—
0.02
0.018
—
—
G
0.98
0.27
0.86
0.003
0.002
0.002
0.05
0.28
0.02
—
—
Ca = 0.004
H
1.18
0.48
1.32
0.004
0.003
0.002
0.12
0.22
0.13
0.002
0.0021
Ti = 0.057, Zr = 0.021
[0000]
TABLE 3
Rolling-
Residence
Residence
Manufac-
Ambient atmosphere
completing
Winding
time of
time of
turing
from finish rolling
temperature
temperature
950° C. or
950° C. or
condition
to start of winding
(° C.)
(° C.)
above (sec)
below (sec)
a
Water cooled
1100
935
0.18
0.14
b
Water cooled
1080
870
0.3
0.14
c
Atmospheric air
1080
870
0.3
0.14
d
Water cooled
1020
815
3
0.13
e
Water cooled
1045
785
14
0.12
f
Atmospheric air
1045
785
14
0.12
g
Water cooled
1090
920
21
0.13
h
Water cooled
1055
860
0.5
0.35
i
Nitrogen
1080
920
0.6
0.14
j
Nitrogen
1020
755
2
0.1
[0000]
TABLE 4
MD performance
Area
Remaining
Manufac-
Scale
ratio
area ratio
Steel
turing
thickness
of fine
after applying
No.
kind
condition
(μm)
holes (%)
6% strain (%)
1
A-1
b
8.6
6.9
19
2
A-1
d
7.1
1.2
11
3
A-1
c
9.2
28
45
4
A-2
b
9.3
5.6
19
5
A-3
d
6.8
3.2
15
6
A-4
e
18.5
0.5
4
7
A-5
i
8.9
8.9
25
8
A-6
j
14.3
0.2
5
9
A-7
d
6.2
2.7
13
10
A-8
i
8.5
9.7
28
11
A-9
b
9.0
4.2
11
12
A-10
j
15.6
2.1
9
13
A-11
e
19.8
1.3
8
14
A-12
i
8.7
6.4
15
15
A-13
d
6.4
4.8
11
16
A-14
j
14.1
0.1
4
17
A-15
i
8.6
7.5
12
18
A-16
e
18.9
4.6
9
19
A-17
d
7.4
3.5
8
20
A-18
b
8.9
3.1
10
21
A-19
j
12.2
1.9
5
22
A-20
e
19.2
2.6
11
23
A-21
i
10.6
3.8
10
24
A-22
b
9.9
3.4
11
25
A-23
d
7.1
2.6
15
26
A-24
e
19.0
1.9
5
[0000]
TABLE 5
MD performance
Area
Remaining
Manufac-
Scale
ratio
area ratio
Steel
turing
thickness
of fine
after applying
No.
kind
condition
(μm)
holes (%)
6% strain (%)
27
B
d
7.8
2.8
8
28
B
j
16.1
1.4
6
29
B
f
19.5
15
35
30
C
b
8.1
5.5
7
31
C
i
9.6
6.8
8
32
D
e
17.9
3.5
6
33
D
c
9.1
39
49
34
E
d
7.7
2.8
5
35
E
j
13.6
2.2
5
36
E
a
5.9
1.1
37
37
F
b
9.0
6.2
9
38
F
e
18.4
2.4
4
39
F
i
8.6
8.2
10
40
F
h
4.5
0.7
42
41
G
d
7.2
1.1
5
42
G
j
12.8
1.8
4
43
G
f
19.5
12
31
44
H
e
17.2
2.2
7
45
H
j
14.6
1.9
7
46
H
c
10.1
41
52
47
H
g
21.8
48
63
[0049] Nos. 1, 2, 4-28, 30-32, 34, 35, 37-39, 41-42, 44-45 of Tables 4, 5 are examples satisfying the requirements of the present invention, the scale thickness and the area ratio of the fine holes inside the scale are appropriate, and therefore the MD property is excellent.
[0050] On the other hand, in Nos. 3, 29, 33, 36, 40, 43, 46, 47, the MD property deteriorated, because the manufacturing condition did not satisfy the requirements of the present invention.
[0051] In Nos. 3, 29, 33, 43, 46, the MD property deteriorated because the wire material was cooled in the atmospheric air after the finish rolling and the area ratio of the fine holes increased. In No. 36, the MD property deteriorated, because the high temperature residence time at 950° C. or above was short and the scale thickness became thin. In No. 40, the MD property deteriorated, because the low temperature residence time at 950° C. or below was long and the scale thickness became thin. In No. 47, the MD property deteriorated, because the high temperature residence time at 950° C. or above was too long, the scale thickness became too thick, and the scale loss increased while the area ratio of the fine holes increased.
[0052] The present invention has been described in detail and referring to a specific embodiment, however, it is clear for a person with an ordinary skill in the art that a variety of alterations and modifications can be added without departing from the spirit and scope of the present invention.
[0053] The present application is based on the Japanese Patent Application No. 2010-290884 applied on Dec. 27, 2010, and the contents thereof are hereby incorporated by reference.
INDUSTRIAL APPLICABILITY
[0054] The steel wire material of the present invention is excellent in the mechanical descaling performance after hot rolling (before drawing work), and is therefore useful as a raw material for a tire cord (steel cord, bead wire) for an automobile, hose wire, a saw wire and the like used for cutting a silicon for a semiconductor and the like.
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This steel wire material contains 0.05%-1.2% C (“%” means “% by mass,” same hereinafter for chemical components.), 0.01%-0.7% Si, 0.1%-1.5% Mn, 0.02% max. P (not including 0%), 0.02% max. S (not including 0%), and 0.005% max. N (not including 0%), with the remainder being iron and unavoidable impurities. The steel wire material has a scale 6.0-20 μm thick and holes of an equivalent circle diameter of 1 μm max. in said scale that occupy 10% by area max. Said scale does not detach in the cooling process after hot rolling or during storage or transportation but can readily detach during mechanical descaling.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to quilting racks. More specifically, the invention is a tabletop quilting rack for use with a sewing machine. The quilting rack has a laser pointer guide, rollers to hold the raw material and the assembled quilt, a carriage, and an aluminum track on which the carriage rides.
2. Description of the Related Art
The related art of interest describes various quilting racks, but none discloses the present invention. There is a need for a quilting rack which is secured adjacent to a sewing machine which rides on a carriage of the rack. A laser pointer guides the tracing of a pattern on the quilt. The related art of interest will be discussed in the order of their perceived relevance to the present invention.
U.S. Pat. No. 4,192,241 issued on Mar. 11, 1980, to Donald K. Reed et al. describes an apparatus for quilting layered fabrics comprising a quilting frame including a sewing machine on a movable carriage. The sewing machine has an extensible sewing head for free-hand quilting. The apparatus has a large rectangular frame with six telescopic legs with three legs on each side. The sewing machine carriage is mounted by linear anti-friction bearings on parallel rails extending from side to side on the frame. Other parallel rails and anti-linear friction bearings extend transversely of the pattern and mount the linear bearings and carriage for movement longitudinally of the quilting fabric. A follower depends from the sewing machine carriage to engage and follow the pattern and controls movement of the carriage to conform to the pattern selected for quilting. The fabric and linear shafts may be adjusted and rotated to maintain the required tension on the material being quilted, and to assure a completed quilt free from wrinkles. The apparatus is distinguishable for requiring a sewing machine with a telescopic head and a large support for manufacturing purposes.
U.S. Pat. No. 5,913,275 issued on Jun. 22, 1999, to John F. Flynn describes a multiple use quilting frame comprising a quilting frame for hand quilting or machine sewing quilting. The frame has three parallel spaced rods individually rotated and locked in a rotated position by engaging splines on the ends of the rods and on the frame ends by the use of a screw threaded knob-type wing nut. The top and bottom layers of the quilt are attached to certain rods and batting inserted from a fourth rod. The three quilt layers are attached to and wound on a third rod, and manipulated for either hand stitching or machine sewing with the rods maintaining the quilt in a taut condition. The device is distinguishable for requiring the addition of batting from a roll between the two rolls of the quilt layers.
Printout of “Handi Quilter”, printed on Mar. 25, 2002, from www.handiquilter.com, 1 page, last updated Mar. 21, 2002, and a printout of Handi Quilter trademark status as of Mar. 20, 2002, with first Use in Commerce Date: Oct. 31, 2000, 2pages. The first source describes the clamping of the Handi Quilter apparatus to a table, and setting the personal sewing machine to a gliding carriage. Telescoping poles allows quilts from 30 inches to Queen bed size quilts to be quilted. The unit is compact, portable and lightweight. The apparatus is dismantled by removing end bolts for storage. The apparatus is distinguishable for requiring a plastic track that is pieced together, taped to the table, but lacks attachment of the side supports. The apparatus requires retrackable buttons, and pieces of material wrapped around the tube supports to attach to the quilting material. The apparatus lacks a laser pointer.
Printout of “Pennywinkle Valley Ranch”, printed on Mar. 25, 2002 from www.pennywinklevalleyranch.com, as best understood describes a home quilting system using a domestic sewing machine mounted on a lower rectangular table top with a second large movable rectangular table top of equal size above it holding the quilt material on presumed rollers.
U.S. Pat. No. 4,665,638 issued on May 19, 1987, to Oscar E. Morton describes a quilting frame designed to stretch and hold material while hand stitching bed quilts. A pair of legs that are adjustable in height and that are free-standing when three rods for holding quilt material are removed from the frame. A hand crank is provided for rotating the rods and a locking device is available for prevention of rod rotation. Tensioning is provided for by a horizontal tensioning mechanism pivotal on link rods attached to one of a pair of horizontal rods of the frame. The device is distinguishable for being limited to hand stitching.
U.S. Pat. No. 4,480,742 issued on Nov. 6, 1984, to Wilfried E. Muylle describes a spreading conveyor apparatus comprising four rollers, an endless air-permeable laterally stretchable spreading band, endless air-permeable supporting band means within the path of the spreading band, and a suction box within the loop of the suction band and having a perforated wall in contact with the inner side of the supporting band means along a portion of its path. The apparatus is distinguishable for being limited to a spreading conveyor.
U.S. Pat. No. 4,315,645 issued on Feb. 16, 1982, to Billy B. Knox describes a rug hooking stand comprising a pair of upright supports for a top supply roller, a mediate roller extending outward on a V-shaped strut, and a pickup roller in line with the first roller. The stand is distinguishable for being limited to a three-roller structure placed in a V-shaped path.
U.S. Pat. No. 3,354,850 issued on Nov. 28, 1967, to Wayne G. Story describes a feed control mechanism for a quilting machine arrangement comprising a means for driving the sewing and workpiece feed mechanisms from a common power source and including a guide mechanism with a differential gearing arrangement to compensate for the relative movement between the feed drive and the feed control mechanisms to provide a uniform speed rate for the feed drive mechanism relative to the speed of the sewing mechanism to insure uniformity of in the length of stitches of the sewing machine. The machine is distinguishable for being limited to a manufacturing process.
U.S. Pat. No. 3,680,507 issued on Aug. 1, 1972, to Giannino Landoni describes a multi-needle quilting machine for performing stitching along different paths, and having the carriage imparting a transverse movement to the quilting material achieved by gear coupling between the main shaft and the drawing roller axle to permit higher velocities of the quilting operation. The machine is distinguishable for requiring gearing.
U.S. Pat. No. 3,960,095 issued on Jun. 1, 1976, to Wayne G. Story describes an automatic quilting machine comprising a frame, a workpiece holding carriage mounted on the frame for universal movement, means for moving the carriage, a sewing mechanism, means for applying tension on the material, and means for automatically operating the carriage moving means, the sewing mechanism and the tensioning means. The machine is distinguishable for being limited to manufacturing quilts.
U.S. Pat. No. 4,669,405 issued on Jun. 2, 1987; U.S. Pat. No. 4,858,540 issued on Aug. 22, 1989; U.S. Pat. No. 5,136,955 issued on Aug. 11, 1992; U.S. Pat. No. 5,913,277 issued on Jun. 22, 1999; to Rodolfo Resta et al. describe an apparatus for cutting and hemming quilts. The apparatuses are distinguishable for being limited to manufacturing quilts.
U.S. Pat. No. 4,953,485 issued on Sep. 4, 1990, and U.S. Pat. No. 4,969,410 issued on Nov. 13, 1990, to David Brower et al. describe an automatic quilting machine for specialized quilting of patterns which can be created by utilizing computer graphics in conjunction with a reprogrammable computer which can be controlled by a remote joystick and monitored by a video screen. The system is distinguishable for being limited to a manufacturing quilting apparatus and method.
U.S. Pat. No. 5,040,473 issued on Aug. 20, 1991, to Manfred Zesch et al. describes a method and apparatus for processing textile material webs such as quilts to obtain simultaneously sewn bands or ribbons and cover the entire width of the quilt material. The apparatus is distinguishable for being limited to a manufacturing quilting machine.
U.S. Pat. No. 5,617,802 issued on Apr. 8, 1997, to David R. Cash describes a multi-needle border machine having folders employable in mattress manufacturing by converting to simultaneously produce up to three border pieces. The machine is distinguishable for being limited to a manufacturing process.
U.S. Pat. No. 5,685,250 issued on Nov. 11, 1997, to Jeff Kaetterhenry et al. describes a quilting method and apparatus for making quilts from unquilted comforter bags. The apparatus is distinguishable for being limited to an assembly line type apparatus.
U.S. Pat. No. 6,151,816 issued on Nov. 28, 2000, to Jim Bagley describes a portable quilting frame assembly with a Z-structure profile comprising two complementary support structures, each of which includes a base member, an elevation member, and a fulcrum member. The two complementary support structures are coupled by a cross member. Coupled to each of the fulcrum members is a rail assembly comprising two complementary rail brace members which hold three rails upon which components of the quilt are separately disposed. The three rails consist of a take-up rail and two supply rails having gearing, i.e., ratchet and pawl, to maintain tension of the quilt between rails. The apparatus is distinguishable for being limited to hand-quilting.
U.S. Pat. No. 5,870,840 issued on Feb. 16, 1999, to Neil Geils et al. describes a stitchery scroll frame and stand for making quilts or rugs. The structure has front and rear rollers extending between two upright rectangular side frames. The scroll frame is distinguishable for being limited to two rollers.
U.S. Pat. No. 5,347,732 issued on Sep. 20, 1994, to Robert S. Padawer describes a needlework scroll frame including slots and two fabric engaging rods. The frame is distinguishable for being limited to only two rollers.
U.S. Pat. No. 5,226,250 issued on Jul. 13, 1993, to Larry Ulmer et al. describes a portable, collapsible craftwork or quilting frame for tensioning textiles comprising a frame having parallel ends and sides supported by parallel legs on leg end plates and feet. The frame is distinguishable for being limited to a rollerless frame.
E.P.O. Patent Application No. 0 275 017 A2 published on Jul. 20, 1988, for Mario Resta et al. describes a quilting machine with an adjustable-length cloth-holder cylinder rotatable about a horizontal axis. The machine is distinguishable for requiring a rotatable cloth-holder cylinder.
E.P.O. Patent Application No. 0 393 474 A1 published on Oct. 10, 1990, for Mario Resta et al. describes a quilting machine with a stationary cloth-holder frame and sewing heads movable in orthogonal directions. The machine is distinguishable for requiring a plurality of movable sewing heads.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus, a quilting rack for sewing machines solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
The present invention is directed to an efficient and reliable quilting rack device integrated with a domestic sewing machine to enable the accurate free-motion machine quilting of one or two layers of fabric material including optional batting between the two fabric layers. One can stitch in any direction, and feel artistically free to make free-hand and stippling designs. Since, the sewing machine moves on its movable rack, there is less stress using this device than pulling the material through a stationary sewing machine. A laser light pointer element in front of the sewing machine on the top plate is provided for tracing patterns from a template placed on the right of the sewing machine. The quilting rack device has a horizontal rectangular aluminum frame with a lower carriage on four wheels travelling from one end to the other. A second carriage on four wheels translates forward and backward while carrying the sewing machine as a rider, and are not clamped to a table. A pair of upright aluminum side angle pieces on each side of the base forward of the sewing machine support plastic racks which hold three metal tubes. The front tube No. 1 rolls clockwise to roll up the unrolling fabric sheets fed from the middle roller No. 2 (top sheet) rotating clockwise and the rear roller No. 3 (bottom sheet) rotating counter-clockwise. There are stops on the lower carriage to prevent the sewing machine from rolling off. The domestic sewing machine can be a pattern programming machine, but the invention prefers manual patterning. Two metal tubes or rollers are arranged to enable the material to roll over with improved support and minimum sag. Hitch pin clips are utilized to hold the metal tubes in place. Slots are formed in the tube supports for an elastic band to slide through to hold the quilt snug from side to side. The elastic band has a snap fastener on one end for fastening to the tube support slot. The quilting rack device can be attached to a wall by brackets and used without a sewing machine and its carriages to free-hand stitch the quilt design.
Accordingly, it is a principal object of the invention to provide a quilting rack device which is combined with a domestic sewing machine on its own movable track to sew free-hand a quilting pattern on a quilt precursor fabric sheet.
It is another object of the invention to provide a quilting rack device having a laser light pointer for tracing patterns from a template.
It is a further object of the invention to provide a quilting rack device having a second carriage translating the sewing machine forward and backward.
Still another object of the invention is to provide a quilting rack device which can be mounted on a wall without using a sewing machine and the carriages by free-hand stitching the quilt design.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an environmental, front perspective view of a quilting rack and a sewing machine in a second movement shown in shadow according to the present invention.
FIG. 2 is an exploded front perspective view of the main track frame and upright roller supports.
FIG. 3 is an exploded front perspective view of the three roller rods attached to the upright roller support arms with each roller rod end having a pawl and ratchet set for unidirectional roller rotation.
FIG. 4 is an exploded perspective view of the wheeled upper carriage which translates forward and backward on a lower carriage.
FIG. 5 is an exploded perspective view of the wheeled lower carriage which translates from side to side on the main track frame.
FIG. 6 is a right side perspective view of the adjustable height roller rod support arms with the tie straps on the base frame.
FIG. 7A is a side elevational view of one of a pair of either (1) a main track frame, (2) king frame or upper extension side pieces, or (3) queen frame or lower extension side pieces.
FIG. 7B is a top plan view of one of a pair of the king frame or upper extension end pieces.
FIG. 7C is a side elevational view of the FIG. 7B end piece.
FIG. 8A is a side elevational view of one of a pair of queen frame or king frame (shorter) lower extension side pieces.
FIG. 8B is a top plan view of one of a pair of the queen frame or lower extension end pieces.
FIG. 8C is a side elevational view of the FIG. 8B end piece.
FIG. 9 is a side elevational view of a cross brace representative of cross braces of the main frame, the queen frame and the king frame. The main cross braces for the queen frame and the king frame are located underneath the queen and king plates.
FIG. 10A is a side elevational view of the main spacer piece.
FIG. 10B is a side elevational view of the stop piece.
FIG. 11 is a side elevational view of the left side support of the base frame.
FIG. 12A is a side elevational view of the top rail for the bottom plate.
FIG. 12B is a top plan view of the top rail for the bottom plate.
FIG. 13A is a top plan view of the bottom rail for the bottom or queen plate.
FIG. 13B is a side elevational view of the bottom rail for the bottom or queen plate.
FIG. 14A is a side elevational view of the bottom rail for the top or king plate.
FIG. 14B is a left side top plan view of the bottom rail for the top or king plate.
FIG. 15 is a front elevational view of one pair of two pairs of roller height or gauge supports.
FIG. 16A is a front side elevational view of the main roller.
FIG. 16B is a front side elevational view of the queen extension roller.
FIG. 16C is a front side elevational view of the king extension roller.
FIG. 17A is a top plan view of the plastic bottom plate.
FIG. 17B is a top plan view of the plastic top plate.
FIG. 18 is a side elevational view of one of a pair of plastic roller supports.
FIG. 19A is a side elevational view of the laser pointer mount.
FIG. 19B is a top plan view of the laser pointer mount.
FIG. 19C is a top plan view of the locking bracket for the laser pointer mount.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is directed to a quilting rack 10 illustrated in FIG. 1 for sewing machines 12 preferably, but can be used without the sewing machine by positioning the rack 10 on a shelf (not shown). The rack 10 has a U-shaped metal frame 14 having a pair of extending side rails 16 supporting a front rail 18 and a rear rail 20 to form a rectangular metal frame 22 . The side rails 16 are actually a queen base extension rail 17 combined with a king base extension rail 19 (hidden inside) adjusted by a knobbed screw 21 to accommodate different lengths of exposed combined fabric sheet material to be stitched together. A first rectangular wheeled carriage or queen carriage 24 translatable from side to side from the extending side rails 16 on the rectangular metal frame 22 . A second rectangular wheeled carriage or king carriage 26 translatable forward and backward on the first wheeled carriage 24 supports the sewing machine 12 . Each of the pair of extending side rails 16 supports an upright roller support element 28 which has a roller support arm 30 horizontally arranged perpendicularly to each upright roller support element 28 . A set of three rollers, i.e., 32 (rear), 34 (middle) and 36 (front), extend between the roller support arms 30 to supply, tension and load, respectively, to a quiltable fabric sheet material 38 comprising two fabric sheets with or without an intermediate batting layer to be quilted. The rollers are formed from rubber or flexible plastic tubes on aluminum tubes. Each of the rollers are rotatable only in one direction. A laser pointer device 40 located on the right side of the second wheeled carriage (king) 26 and positioned by a laser pointer mounting element 42 (FIGS. 19A-19C) to incline slightly toward the sewing needle 43 by an inclined throughbore 44 . A hand-made or commercially available pattern stencil (not shown) is used to mark a pattern on the quiltable fabric sheets 38 , whereby the quiltable fabric sheet material 38 can be patterned by the sewing machine 12 following the illuminated stencilled pattern on the movable quiltable fabric sheet material 38 .
Each horizontal roller support arm 30 is adjustable in height on each upright roller support element 28 , and has a pair of straps 46 for tensioning the quiltable fabric sheet material 38 from side to side with pins 48 as seen in FIG. 1 . It should be noted that the pins 48 are used only temporarily to hold the sheet material 38 taut until the stitching is completed for that segment of the fabric sheet material 38 .
The first rectangular wheeled queen carriage 24 has four grooved wheels 50 with two wheels on each side traversing on top of the parallel front rail 18 and the rear rail 20 attached to the front portion of the pair of extending side rails 16 . The second rectangular wheeled king carriage 26 has four grooved wheels or sheaves 50 with two wheels on each side traversing on top of the parallel side rails 52 of the first rectangular wheeled queen carriage 24 .
The unidirectional rotations of the three rollers will be described now with reference to FIG. 1 from the front of the apparatus. The rear supply roller 32 rotates only in a counter-clockwise direction as depicted by a directional arrow, where as the loading roller 36 and the tension or intermediate roller 34 rotate only in a clockwise direction. The unidirectional rotation of the three rollers are controlled by a set 54 of a pawl and a gear wheel (serrated in a direction to hold the pawl) on one end of each roller. The two sheet materials 38 from the clockwise rotating roller 32 and the counter-clockwise rotating roller 34 come together with an optional batting layer (not shown) already installed on one or both of the unrolling sheets, and are rolled up counter-clockwise on the loading roller 36 .
In FIGS. 1 and 2, the rectangular metal frame 22 has a welded mid-brace 56 and a diagonal brace 58 formed of unflanged metal strips for reinforcing the frame 22 . The pair of right-angled extending side rails 16 are secured to the narrow ends of metal frame 22 by knobbed set screws 21 through apertures 64 . The side rails 16 in turn support the upright roller support element 28 which is actually a composite of two flanged rails 66 providing a space for a pair of wing nuts 68 to hold the horizontal roller support arm 30 between the flanges at a predetermined adjustable height.
Returning to a more complete description of the upright roller support element 28 depicted in FIGS. 2 and 6, and the is horizontal roller support arm 30 illustrated in FIGS. 2, 3 , 6 , and 18 , the horizontal roller support arm 30 has a straight upper surface 70 and enlarged rear head portion 72 for supporting the three rollers 32 , 34 and 36 in fixed straight horizontal position with wire clips 74 outside the roller support arm 30 in apertures 64 of the roller ends and bushings 76 inside the enlarged apertures 78 of the support arm 30 .
The advantage of adjusting the level of each horizontal roller support arm 30 without twisting on each upright support element 28 with the two in-line wing nuts 68 enables the sewer to position any sewing machine 12 to the enabling position for proper stitching of the fabric sheet material 38 .
The wooden or metal rod 80 at the front edge of the second rectangular wheeled carriage or king carriage 26 and extending past its sides enables control of the second carriage forward and rearward.
FIGS. 4 and 5 depict an exploded view of the smaller top king carriage 26 and the lower queen carriage 24 , respectively. The heavy duty white polyethylene rectangular king plate 82 in FIG. 4 has a parallel pair of bottom aluminum angle rails 84 shown also in FIGS. 14A (side view) and 14 B (top view) with apertures 64 for bolting to the corners of the king plate 82 with bolts 60 and nuts 62 , and the wood or metal control rod 80 in front. The four grooved wheels or sheaves 50 are attached to the angle rails 84 by similar nuts and bolts into apertures 64 . In FIG. 4, the laser pointer device 40 is mounted in the inclined throughbore 44 of the laser mounting element 42 as discussed earlier in FIGS. 19A and 19B. The mounting element 42 has a notch 86 at the end opposite the laser mounting throughbore 44 in its upper surface to fit against the side and bottom of the king plate 82 and held there by the doubly apertured rectangular plate 88 of FIG. 19C on top of the edge of king plate 82 by a wing nut 68 and a bolt 60 in the proximate aperture for easier loosening for movement of the mounting element 42 to another position. The distal fastener is a bolt 60 and nut 62 .
The queen plate 90 in FIG. 5 is made of similar material and is a larger rectangular plate than the king plate 82 (see FIGS. 17A and 17B) with its pair of parallel bottom side rails 92 attached by bolts 60 and nuts 62 which also fasten the upper pair of parallel side rails 94 which are perpendicular to the bottom side rails 92 . The upper rails 94 have a welded stop plate 96 to prevent the rear wheels or sheaves 50 of the king plate 82 with the sewing machine 12 from moving further back off the upper rails 94 . The lower rails 92 support the queen plate 90 on four wheels 50 on bolts 60 with nuts 62 .
Turning to FIGS. 7A-C, one of the pair of longer main track frame sides 18 and 20 approximately 66 inches in length is depicted in FIG. 7A with flanges 98 on the bottom and outside apertures 64 for joining with the pair of flanged end pieces 100 with one end piece illustrated in a side view in FIG. 7 B and in a top view in FIG. 7 C. The large apertures 102 in FIG. 7B are for the knobbed adjusting screws 21 to extend the side rails 16 of the frame 14 . The smaller apertures 64 proximate the ends of flanged end pieces 100 and the main frame sides 18 are for joining the main track frame sides 18 to the end pieces 100 to form the rectangular metal frame 22 for the carriages 24 and 26 .
FIGS. 8A-C are representative of the king extension pair of bottom angle rails 84 in FIG. 4 and the shorter upper queen extension pair of the upper angle rails 94 and the shorter pair of equal sized bottom rails 92 with larger apertures 78 in FIG. 5 .
FIG. 9 depicts cross braces 104 of different lengths for the rectangular frame 22 (FIG. 1) with apertures 64 , for the queen carriage 24 (hidden under the plate), and for the king carriage 26 (hidden under the plate) which are fastened to the flanges of the aforementioned angle elements.
FIG. 10A illustrates the main spacer or mid-brace element 56 for the metal frame 22 . FIG. 10B shows the stop plate 96 on the queen carriage 24 in FIG. 1 . FIG. 11 depicts the left side support or the extending side rail 16 of the base frame 14 shown in FIG. 1 . FIGS. 12A and 12B show, respectively, a side view and a top view of the top left rail 94 with an aperture 64 on the left for the stop plate 96 of FIG. 5 . FIGS. 13A and 13B show, respectively, top and side views of one of the pair of bottom rails 92 supporting the queen plate 90 of FIG. 5 . FIGS. 14A and 14B illustrate a side view and a top view, respectively, of one of a pair of bottom rails for the king plate 82 which are shorter in length than the bottom rails 92 of the queen plate 90 . In FIG. 15, one pair of the upright roller support element 28 is shown with the flanges 66 separated for inclusion of the In FIGS. 16A, 16 B and 16 C, a system of increasing the lengths of the rubber or plastic rollers on metal tubes 106 to accommodate the quilting of blankets for a regular size bed, a queen size bed or a king size is illustrated. The larger queen size bed blanket is accommodated by inserting the queen extension roller 108 (FIG. 16B) and its exposed insert portion 106 into one end of the main regular size bed roller 110 (FIG. 16 A). If a king size bed blanket is to be stitched, the king extension roller 112 is added to the queen extension roller 108 via its insert portion 106 . The apertures 64 provide securement of each roller segment by pins (not shown here). The metal frame must be enlarged to accommodate the increased roller lengths.
FIGS. 17A and 17B, respectively, show the relative sizes of the queen plate 90 , e.g., 20 in. by 8 in., and the king plate 82 , e.g., 18 in. by 8 in. with appropriate apertures 64 . The sizes of the plate rails would have commensurate sizes.
FIG. 18 is the horizontally arranged roller support arm 30 for positioning on each upright roller support element 28 (FIG. 1 ). Arm 30 is preferably made of white plastic or Teflon (TM) in the shape shown with a straight upper edge 70 , an enlarged head 72 for supporting the rear supply roller 32 (not shown) and the tension roller 34 (not shown) in the apertures. The two smaller apertures 64 are for fastening to the upright roller support element 28 . The slots 78 are for passing through the straps 46 to pin to the edge of the combined fabric sheet material 38 as seen in FIG. 1 .
Thus, a quilting rack having the property of extending the length of the rollers and the size of the frame is advantageous in addition to the moving capacities of the king and queen carriages.
It is to be understood that the present invention is not limited to the embodiment described above, but encompasses any and all embodiments within the scope of the following claims.
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A quilting rack for sewing machines comprising a U-shaped rectangular metal frame supporting a wheeled bottom or queen carriage for side to side translation of a wheeled upper king carriage capable of forward and rearward translation of the sewing machine it is carrying. Three rollers supply, tension and load the quilt for sewing patterns guided by a laser pointer and a template. The quilting rack can be utilized without a sewing machine by mounting on a wall or shelf.
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PRIORITY CLAIM
[0001] This application is a non-provisional application claiming priority to U.S. Provisional Patent Application No. 61/799,158, filed Mar. 15, 2013 and titled “Mass Dependent Automatic Gain Control for Mass Spectrometer,” all of which is incorporated herein by reference.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates generally to mass spectrometry and, more particularly, to systems and methods of mass-dependent automatic gain control.
BACKGROUND OF THE DISCLOSURE
[0003] Mass spectrometers are instruments used to analyze the mass and abundance of various chemical components in a sample. Mass spectrometers work by ionizing the molecules of a chemical sample, separating the resulting ions according to their mass-charge ratios (m/z), and then detecting the abundance of ions at each m/z. The resulting spectrum can be interpreted to reveal the relative amount of each chemical component in the sample based on the abundance of the mass fragments of these components.
[0004] Various mass spectrometers generate ions from the sample utilizing various methods, for example, electrospray ionization, atmospheric pressure chemical ionization, matrix-assisted laser desorption/ionization, and inductively coupled plasmas. In some situations, the ion source that generates the ions is located external to a mass analyzer. The ions are guided from the ion source into a mass analyzer, where the ions are separated based on mass. The ions then arrive at a detector that detects charge and/or current. Information based on the detected charge and/or current is then used to determine the quantity of ions of various masses.
[0005] One type of mass analyzer used for mass spectrometry is called a quadrupole ion trap. Quadrupole ion traps take several forms, including three-dimensional ion traps, linear ion traps, and cylindrical ion traps. The operation in all cases, however, remains essentially the same. DC and time-varying radio frequency (RF) electric signals are applied to the electrodes to create electric fields within the ion trap. These fields trap ions in a “cloud” within the central volume of the ion trap. By manipulating the amplitude and/or frequency of the electric fields, ions are selectively scanned out by being ejected from the ion trap in accordance with their m/z. A detector records the number of ejected ions at each m/z as they arrive.
[0006] Ion traps are optimized for a combination of speed, sensitivity, and resolution depending on the particular application. For a given instrument, an improvement in one category is usually made at the expense of another. For example, sensitivity can generally be increased by using a slower scan, and in the reverse, a scan can be performed faster at the expense of sensitivity. Similarly, sensitivity—especially to less abundant components of a sample—can be increased by trapping and scanning a larger total number of ions in a single scan. However, as the quantity of ions in the trap increases, the coulombic forces and collisions between the like-charged ions in the ion cloud increases, resulting in space charge effects. Mass spectrometers achieve resolution by ejecting all ions of the same m/z at close to the exact same moment. However, when space charge effects become significant, ions are ejected from the trap at different times. The result is broadening of spectral peaks and loss of resolution. Also, detectors used in mass spectrometers typically have a limited dynamic range, the difference between the lowest and highest concentration that can be detected. Concentrations lower than the lower bound are undetectable due to, for example, noise; and concentrations above the upper bound may saturate the detector. Additionally, mass analyzers may trap ions preferentially based on their mass, thus for a sample with a range of masses, larger ions may not be trapped as efficiently as lower masses.
[0007] There is a need for systems and methods for expanding the range of concentrations detectable by mass spectrometers. The present disclosure is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.
SUMMARY OF THE DISCLOSURE
[0008] Embodiments of the present disclosure relate to chemical analysis instruments, such as mass spectrometers, that utilize automatic gain control. Various embodiments of the disclosure may include one or more of the following aspects.
[0009] In one aspect, the present disclosure is directed to a mass spectrometer. The mass spectrometer may include a lens configured to receive a supply of ions, and a mass analyzer downstream of the lens. The mass analyzer may include an ion trap and an ion detector. Furthermore, the lens may focus a beam of the ions non-uniformly based on the mass of the ions to compensate for space charge effects reflected in a measurement output of the mass spectrometer.
[0010] In another aspect, the present disclosure is directed to a mass analyzing control system for analyzing the mass of a sample. The system may include one or more memories storing instructions. The system may also include one or more processor configured to execute the instructions to perform operations. The processor may obtain a mass spectrum of an ion beam generated from the sample and identify a space charge characteristic based on the mass spectrum. The processor may defocus the lens based on the mass spectrum or detector saturation, wherein defocusing the lens may correspond to preferentially defocusing away lighter ions. The processor may then obtain a mass spectrum of a defocused ion beam generated from the sample.
[0011] In yet another aspect, the present disclosure is directed to a method for analyzing the mass fragments of a sample. The method may include focusing an ion beam into a mass analyzer. The method may include obtaining a mass spectrum of the ion beam and identifying a space charge characteristic, or other mass dependent phenomena, based on the mass spectrum. The method may also include defocusing the lens based on the identified space charge characteristic, or other mass dependent phenomena, wherein defocusing the lens corresponds to preferentially defocusing away lighter ions. The method may further include obtaining a mass spectrum of a defocused ion beam generated from the sample.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The drawings are not necessarily to scale or exhaustive. Instead, emphasis is generally placed upon illustrating the principles of the inventions described herein. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure. In the drawings:
[0013] FIG. 1 is a pictorial illustration of a mass spectrometer according to some embodiments of the invention;
[0014] FIGS. 2A and 2B depict exemplary spectra with and without space charge effects; and
[0015] FIGS. 3A , 3 B, and 3 C depict simplified flight paths of ions for various voltages applied to an ion lens.
[0016] FIG. 4 depicts another view of simplified flight paths of ions defocused preferentially by mass.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0017] Reference will now be made in detail to the embodiments of the present disclosure described below and illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to same or like parts.
[0018] FIG. 1 is a schematic diagram of a mass spectrometer 100 according to an embodiment of the invention. Mass spectrometer 100 may include an ion source 105 for generating sample ions 107 from a sample and an ions lens 110 for focusing and defocusing ions 107 . Mass spectrometer 100 may also include a mass analyzer 115 . In some embodiments, mass analyzer 115 may be an ion trap-type mass analyzer. Mass analyzer 115 may receive ions 107 after they have been focused or defocused by ion lens 110 . Eventually, ions 107 are scanned out of mass analyzer 115 , detected by detector 128 , and then converted into usable data by various components, such as an A/D converter 130 and a field-programmable gate array (“FPGA”) 140 .
[0019] In various embodiments, ion source 105 may be any apparatus that produces sample ions 107 by ionizing a sample that is introduced into mass spectrometer 100 . For example, ion source 105 may include an electron ionization device comprising an electron filament, which is heated to a high enough temperature such that it emits energetic electrons. Ion source 105 may include an electron lens that focuses and accelerates the electrons into the sample, resulting in ionization of the sample and generation of sample ions 107 . Alternatively, ion source 105 may be other types of devices that ionize samples by various methods, e.g., chemical ionization or inductively coupled plasma. In various embodiments, ion source 105 may generate ions 107 at a relatively high pressure, such as at around atmospheric pressure. In addition to ions 107 , ion source 105 may contain a background gas, such as nitrogen, to which most of the pressure is attributed.
[0020] When ions 107 are emitted from ion source 105 , ions 107 may begin to disperse unless focused by ion lenses. Ion lenses may be biased at various potentials to activate. The resulting electric field may result in electric forces on ions 107 that accordingly define the path of ions 107 . In some embodiments, mass spectrometer 100 may include one or more ion lenses 109 that focus ions 107 into a beam. Mass spectrometer 100 may also include ion lens 110 that controls the degree to which the beam of ions 107 are focused or defocused before entering mass analyzer 115 . The direction and acceleration of ions 107 passing through an aperture 113 of ion lens 110 may be controlled based on the voltage applied to ion lens 110 . In addition, changing the voltage applied to lens 110 may affect the cross-sectional area of the ion beam. Accordingly, the proportion of ions 107 that pass through lens 110 into mass analyzer 115 may vary based partly on the voltage applied to lens 110 . Lens 110 may then act as a voltage-controlled gate for controlling the number of ions 107 that enter the mass analyzer 115 .
[0021] Mass analyzer 115 may include a first end cap electrode 116 , a ring electrode 117 , and a second end cap electrode 118 . First end cap electrode 116 may have an aperture 119 , through which ions 107 are received by mass analyzer 115 . By applying voltages to end caps 116 and 118 , and a voltage to the ring electrode 117 , which may be DC, AC, or combination of AC and DC voltages, an electric field may be generated in mass analyzer 115 . By appropriately setting the field strength, shape, and frequency of the field, ions 107 that enter mass analyzer 115 may be trapped as an ion cloud within mass analyzer 115 . However, ions 107 are not trapped statically in the ion trap. That is, ions 107 may continue to move within the ion cloud, based on the generated RF fields, electrostatic interactions among ions 107 , and collisions with background gas particles.
[0022] The strength of the RF field and/or the frequency of the RF field may then be adjusted to selectively scan out ions 107 based on the mass (more specifically, the mass-to-charge ratio) of the ions. Ions 107 may be scanned out through an aperture 121 in second end cap 118 , and received by ion detector 128 . In some embodiments, a focusing lens 126 may precede ion detector 128 . Focusing lens may include an aperture 127 that is covered with a screen or grate that shields mass analyzer 115 from strong electric fields generated by a high voltage on ion detector 128 . For example, ion detector 128 may be biased with a voltage on the order of −2,000 V. Ion detector 128 may receive ions 107 and generate a detection signal. The output of ion detector 128 may feed into an ion amplifier 129 , which may be positioned in close proximity to ion detector 128 . Ion amplifier 129 may serve to buffer the output of the ion detector 128 , and allow for transmission to A/D converter 130 via a low-impedance signal line that is less susceptible to electromagnetic interference than the output of ion detector 128 . An A/D converter 130 may translate the analog output of the ion amplifier 129 into a digital signal to be read by field-programmable gate array (“FPGA”) 140 and eventually processed into an output spectrum to be read by a user or stored for future use. The output spectrum may depict the number of ions 107 as a function of mass. In some embodiments, the A/D converter 130 and FPGA 140 may be combined into a single complex device such as a digital signal processor (“DSP”), microprocessor, or any combination of analog or digital components known in the art.
[0023] In various embodiments, the resolution of the output spectrum may be affected by space charge or other effects that affect the resolution of the mass spectrometer 100 . For example, space charge effects are due to numerous like-charged ions 107 being confined to a limited space. In various situations, the electric fields generated within mass analyzer 115 may be working to keep ions 107 close together at the center. But due to the closeness of so many like-charged ions 107 , ions 107 may experience counteracting electrostatic repulsive forces. Such space charge effects may introduce irregularities to the motion of ions 107 within the ion cloud and subsequently alter the resulting mass spectrum measured by detector 128 . In addition, some effects may preferentially affect ions based upon their mass. For example, collisions with neutral species such as background gasses will affect the trajectory of smaller ions more significantly than larger ions.
[0024] FIGS. 2A and 2B show exemplary spectra generated by mass spectrometer 100 without space charge effects and with space charge effects. In FIG. 2A , peaks 211 and 212 indicate the presence of two isotopes of a same ion. In the absence of space charge effects, the peaks are easily discernible. In various embodiments, as the quantity of ions trapped in mass analyzer 115 increases, space charge effects begin to manifest such that spectral peaks widen and isotopes blur together. For example, in FIG. 2B , the midpoint between peaks 221 and 222 , which represent the same isotopes as peaks 211 and 212 in FIG. 2A , no longer drops back to the baseline.
[0025] FIG. 2B also reveals that space charge effects are more pronounced at lower masses. The loss in resolution from peak 212 to 222 is not as severe as the loss of resolution from 213 to 223 , where identification of isotopes, and in fact the identity of the main peak, has become impossible. There are various possible reasons for space charge effects manifesting more heavily at lower masses. One reason may be due to the fact that ions are scanned out of mass analyzer 115 in order from low mass to high mass. Low mass ions are scanned out of mass analyzer 115 when the ion trap is still full. Accordingly, space charge effects are more severe due to the higher number of charged ions still in the ion trap contributing to space charge. By the time higher mass ions are scanned out of the ion trap towards the end of the scan, only higher mass ions are left in the ion trap. Because the number of charged particles has reduced, space charge effects may likewise be reduced. Another reason that space charge effects may manifesto a greater extent at the lower end of a mass spectrum may be due to greater deflection of lighter masses as compared to heavier masses. That is, as various ions move towards each other and then repel each other, due to the electrostatic repulsive forces, the heavier ions may displace a small distance from the center of the ion trap, while the lighter ions may displace a much larger distance from the center. A useful analogy may be to consider a ping pong ball and a bowling ball. If a ping pong ball and a bowling ball collide, the ping pong ball tends to ricochet off the bowling ball with substantial speed and large deflection. The bowling ball, on the other hand, barely moves as result of the interaction with the ping pong ball. Similarly, as all of the ions 107 in mass analyzer 115 move about within the center and experience near-collisions with each other, lighter ions may be deflected more from the center of mass analyzer 115 as compared with heavier ions. The more that a set of ions 107 of the same mass are dispersed within mass analyzer 115 , the less likely that all of the ions are successfully scanned out simultaneously. As a result, spectral broadening occurs in the measurement. On the other hand, the more that trajectory of the set of ions 107 are controlled by the electrical signals applied to mass analyzer 115 and less by space charge effects, the more likely that all of the ions are scanned out near simultaneously and that a clean spectral peak can be obtained.
[0026] FIGS. 3A , 3 B, and 3 C illustrate varying degrees of focusing by ion lens 310 . Such adjustments may be utilized to control the extent of space charge effects exhibited in a measured spectrum, according to some embodiments. In FIG. 3A , ion source 305 may generate ions 307 , which then may be focused by intermediary ion lenses 309 . After emerging from ion lenses 309 , ions 307 may continue to travel towards first end cap 316 of a mass analyzer, passing through aperture 313 of ion lens 310 along the way. A voltage may be applied to ion lens 310 such that the beam of ions 307 is focused or defocused accordingly. In some embodiments, for positive ions 307 , the applied voltage may be a negative voltage that results in some of ions 307 passing through aperture 319 while others hit first end cap 316 . In FIGS. 3B and 3C , the voltage applied to ion lens 310 may be adjusted such that the beam of ions 307 becomes relatively more or less focused. For example, in FIG. 3B , the voltage applied to ion lens 310 may be adjusted to be more negative than in FIG. 3A . As a result, ion lens 310 may focus ions 307 into a narrower beam, and subsequently, a higher proportion of ions 307 may pass through aperture 319 . In FIG. 3C , the voltage applied to ion lens 310 may be adjusted to be less negative than in FIG. 3A . As a result, ion lens 307 may defocus the beam of ions 307 such that a lower proportion of ions 307 pass through aperture 319 . The number of ions 307 that enter the ion trap may therefore be reduced. In various other embodiments, when ion lens 310 is adjusted to be more positively biased, the beam of ions is defocused, and when ions lens 310 is adjusted to be more negatively biased, the beam of ions is focused.
[0027] Furthermore, the trajectory of the ion will be affected by the electric field created by lens 310 according to the vector force applied to the ion:
[0000] {right arrow over (F)}=q{right arrow over (E)}
[0000] where F is the vector force applied to the ion, q is the charge on the ion, and E is the vector electric field strength. The change in the trajectory of the ion will be defined by:
[0000] {right arrow over (F)}=m{right arrow over (a)}
[0000] where F is the vector force from the applied electric field, m is the mass of the ion, and a is the vector acceleration. Since the force applied to the ion is defined only by the electric field strength and the charge, which may be similar for like ions; and the change in trajectory is dependent only upon the mass and applied acceleration, the change in ion trajectory will depend upon the mass of the ion, provided that the ions are travelling at relatively the same velocity. This dependence is shown in FIG. 4 , which is a magnified view of ion beam 407 passing through ion lens 410 and arriving at aperture 419 of first end cap 416 . FIG. 4 shows the trajectories of exemplary light, medium, and heavy ion masses, wherein ion lens 410 preferentially defocuses away ions based on mass. Thus, referring back to FIG. 3 , ion lens 310 may defocus ions 307 preferentially based on the mass of ions 307 . That is, lighter ions may tend to be deflected away from the central axis of the beam of ions 307 arriving at aperture 319 . However, heavier ions may not be deflected as much. Therefore, in FIG. 3C , ions 307 that arrive inside the ion trap may preferentially include heavier ions 307 . That is, lighter ions 307 may be deflected such that they are at the edge of the beam and hit the surface of first end cap 316 instead of passing through aperture 319 . In various embodiments, by preferentially defocusing the beam of ions 307 , the number of lighter ions, which are the ions that exhibit more space charge effects, is reduced in the ion trap. In such manner, the overall space charge effects exhibited by the measured spectrum may be improved.
[0028] Another way to understand this improvement on space charge effects may be as follows. Lens 310 may preferentially focus and defocus lighter ions 307 . A plot of the response of the lens, such as attenuation for a given applied voltage as a function of mass, would have a negative slope. This negative slope is due to the fact that lighter ions are defocused and deflected more than the heavier ions. In addition, a plot of the ion trap with respect to space charge, such as resilience to space charge effects as a function of mass, would have a positive slope. This positive slope is due to, as discussed above, space charge effects affecting lighter mass ions more than heavier mass ions. If these two plots are added, the mass-dependent space charge effects may cancel, to a first order approximation.
[0029] In various embodiments, an exemplary method for reducing space charge effects exhibited in a measured spectrum may be as follows. The ion trap may be loaded with ions 307 . The resulting spectrum may exhibit space charge effects at the lower end of the mass spectrum. The voltage applied to ion lens 310 may then be adjusted such that the beam of ions 307 is defocused away from aperture 319 , preferentially for the lighter ions. Because the lighter ions have been preferentially defocused away, less of the lighter ions may enter the ion trap via aperture 319 . As a result, overall space charge effects may be reduced.
[0030] In some embodiments, the resulting spectrum after the beam of ions 307 is defocused may show an improvement with respect to space charge effects. However, the proportion of masses trapped in the ion trap and subsequently detected by the detector may be skewed, since lighter ions 307 are preferentially defocused away. A compensation for such spectral skew may be performed by various methods and algorithms after the spectrum has been obtained. For example, a computing processor (not shown) may execute instructions stored in memory for computationally adjusting the measured spectrum. As another example, another run of measurements may be performed, where lighter ions are preferentially focused into the ion trap. The resulting mass spectrum may then be combined with the first mass spectrum to derive a new mass spectrum with spectral skew removed and reduced space charge effects.
[0031] In some other embodiments, the beam of ions 307 may be defocused without preference based on mass. For example, ions 307 may be generated and/or manipulated to have uniform momentum. The momentum of each ion 307 is defined by:
[0000] {right arrow over (p)}=m{right arrow over (v)}
[0000] where p is the vector momentum of the ion, m is the mass of the ion, and v is the vector velocity of the ion. Because ions 307 may have different masses, different ions 307 will travel at different velocities in order for ions 307 to have uniform momentum. Heavier ions may move at a slower velocity while lighter ions may move at a faster velocity. As ions 307 pass through aperture 313 in ion lens 310 , the electrostatic force generated by ion lens 310 may focus or defocus ions 307 . In some embodiments, as ions 307 travel from ion lens 310 to end cap 316 , the lighter ions will be accelerated by ion lens 310 in the y-direction (perpendicular to the axis connecting aperture 313 and aperture 319 ) more than the heavier ions. As discussed above, in situations where ions 307 have uniform velocity, the larger acceleration causes larger deflection of the lighter ions. However, when ions 307 enter ion lens 310 with uniform momentum, the lighter ions may be traveling at a faster velocity than the heavier ions. Therefore, even if the lighter ions experience greater acceleration in the y-direction, the lighter ions also traverse the distance between ion lens 310 and end cap 316 more quickly. Accordingly, the lighter ions traverse this distance in less time, which results in smaller deflections in the y-direction before the lighter ions arrive at end cap 316 . The heavier ions, on the other hand, travel the distance between ion lens 310 and end cap 316 more slowly, allowing for more time during which the heavier ions are deflected in the y-direction. In some embodiments, the fact that lighter ions are accelerated in the y-direction more than the heavier ions, but the heavier ions take longer to arrive at end cap 316 than the lighter ions may result in lighter ions and heavier ions being deflected by relatively the same amount. Therefore, ions 307 of various masses may be focused and defocused by ion lens 310 without preference based on mass.
[0032] In embodiments that utilize ions 307 with uniform momentum, ion lens 310 may focus and defocus the beam of ions 307 such that a greater or lesser proportion of ions 307 enter mass analyzer. The group of ions 307 that enter the mass analyzer may maintain the same proportion of the various masses of ions 307 that is originally present in the beam that is focused or defocused by ion lens 310 . By reducing the number of ions 307 that are trapped simultaneously in the mass analyzer, space charge effects may be reduced.
[0033] It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed systems and methods. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed systems and methods. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.
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Systems and methods for automatic gain control in mass spectrometers are disclosed. An exemplary system may include a mass spectrometer, comprising a lens configured to receive a supply of ions, and a mass analyzer. The mass analyzer may include an ion trap for trapping the supplied ions. The mass analyzer may also include an ion detector for detecting ions that exit the ion trap. The lens may focus the ions non-uniformly based on mass of the ions to compensate for space charge effects reflected in a measurement output of the mass spectrometer. An exemplary method may include focusing an ion beam into a mass analyzer. The method may also include obtaining a mass spectrum and identifying a space charge characteristic based on the mass spectrum. The method may further include defocusing the lens based on the identified space charge characteristic, wherein defocusing the lens is configured to divert lighter ions away from the entrance aperture. The method may include obtaining a mass spectrum of a defocused ion beam generated from the sample.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority based on U.S. provisional application 60/970,144, filed on Sep. 5, 2007.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The present invention relates to devices for dispensing toilet bowl treating chemicals (e.g. soaps, disinfectants, sanitizers deodorizers, fragrances, colorants, etc.). More specifically it relates to such devices that allow a consumer to direct when the chemicals will be dispensed into the toilet bowl water, while minimizing the need for consumers to scrub the toilet bowl.
Toilet bowls require care to prevent the buildup of unsightly deposits, to reduce odors and to prevent bacteria growth. Originally toilet bowls were cleaned, deodorized and/or otherwise treated by manual scrubbing with a liquid or powdered cleaning/sanitizing agent that was added to the bowl water by hand. This required manual labor to keep the toilet bowl clean.
To reduce or in some cases eliminate the need for manual scrubbing, various automatic toilet bowl cleaning systems have been created. One type of system delivers the cleaning chemical by adding it to the flush water while the flush water was still stored in the toilet tank. Some embodiments of this type of system add the chemical to the flushing cycle in liquid form. Others place a block of cleaning chemical in the toilet tank, to slowly dissolve over several weeks or longer.
However, a system which relies on adding the chemical to the storage tank typically requires the consumer to lift a tank lid in order to install the device and/or to add a new charge/block of cleaning chemical. Also, with some of such systems, precise control over the quantity of chemical to be delivered is difficult. For example, different water hardness from the supply may cause different cleaning blocks to dilute at different rates. Further, when the chemical is placed in the storage tank the cleaning chemical must be compatible for long-term contact with some of the valving present in the toilet tank, which may impose some limitations.
An alternative type of system hangs a dispenser adjacent and/or immediately under the toilet bowl rim. Water flowing from the rim washes over the dispenser, thereby triggering dispensing of the stored chemical directly into the bowl water. However, some consumers prefer not to have the ornamental exterior of their toilet disrupted by the presence of a hook hanger. Still others are reluctant to maintain such dispensers given that they are so close to the waste bowl, and the consumers don't want to reach near that area.
In any event, such systems are designed to dispense in response to each flush. In some situations where increased amounts of flushing are occurring (e.g., a curious child, a large number of guests, a family's return from a long car-trip) cleaning chemicals may not be necessary after every flushing. Thus, some of these systems use up more cleaning chemicals than is actually needed.
There have been attempts to associate toilet bowl chemical dispensers with the lids or other coverings of toilets, or near them. See e.g. U.S. Pat. Nos. 713,978, 749,963, 979,386, 988,178, 3,840,914, 4,216,553, 4,819,276 and 6,745,417, and U.S. patent application publication 2006/0097189. However, these systems suffer from many of the deficiencies noted above. For example, it is typical with many of such systems to have dispensing occur with every lid movement, regardless of need.
It can therefore be seen that improvements are desired with respect to toilet bowl cleaning assemblies that dispense cleaning chemicals.
BRIEF SUMMARY OF THE INVENTION
In one aspect the invention provides a toilet bowl treating assembly comprising a cover suitable to be pivotably mounted to a rearward portion of the toilet bowl so as to pivot between a somewhat upright position and an essentially horizontal position. There is also a dispenser mounted to the cover and having an outlet on an underside of the cover, and a plurality of solid pills stored in the dispenser so as to be dispensable there from. At least one of the pills comprises a toilet treatment chemical, and, when the cover is so mounted, pivoting of the cover to the upright position can restrict dispensing of a pill. For example, the toilet treatment chemical could include surfactants, fragrances and colorants, and mixtures thereof.
The cover can be selected from the group consisting of toilet seats and toilet lids, with lids being preferred. In preferred embodiments there can be an actuator for moving a pill in response to a manual force having been applied to the actuator. The actuator is linked to a return spring such that after it is caused to move a pill, the spring will cause the actuator to move back to a rest position.
When the cover is down, and the actuator used, gravity can assist in driving a pill out the outlet. The pills are preferably stored in a waiting line that is either serpentine or in the form of a stack with adjacent pills abutting each other in face-to-face fashion. Most preferably, the pills can be stored in a cartridge unit which can be separated from the dispenser when the pills have all been dispensed from the dispenser.
By the term “pill” it is intended to mean a solid mass of a size larger than what would be viewed as powder, regardless of shape. Hence, the pills may be disk shaped, or spherical, or elongated, or have other configurations. Tablet shapes are most preferred.
In one alternative embodiment, pivoting the cover from the somewhat upright position to the essentially horizontal position dispenses a pill automatically to the toilet bowl when the pill has previously been positioned in a “ready” position of the dispenser. The assembly may have an actuator for moving a pill from a storage area of the dispenser to the ready position in response to a manual force having been applied to the actuator. The actuator could be in the form of a slide for driving a lower one of the pills to the ready position, and the ready position may be in the form of a delivery slot. The actuator may also contain a lock which can, when activated, inhibit use of the actuator to move a pill to the ready position.
Once a pill has reached the ready position in this embodiment, and the cover has been positioned so as to extend essentially horizontally, gravity will drive the pill out the delivery slot. Thus, when a consumer closes the lid after using the toilet, if the pill has been pre-positioned in the ready position the movement of the lid causes the bowl to be treated. However, if the consumer thinks the bowl is sufficiently clean, and doesn't pre-position the pill to the ready position, no dispensing will take place.
The foregoing and other advantages of the present invention will be apparent from the following description. In that description reference is made to the accompanying drawings which form a part thereof, and in which there is shown by way of illustration, and not limitation, preferred embodiments of the invention. Such embodiments do not necessarily represent the full scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a toilet seat assembly which includes a dispenser of the present invention;
FIG. 2 is a fragmentary side view of a toilet on which an embodiment of the present invention has been mounted;
FIG. 3 is a view similar to FIG. 2 , but with the lid shown in the horizontal position; side view of the cleaning assembly of FIG. 1 , albeit with the cover in the essentially horizontal position;
FIG. 4 is an enlarged view of the dispenser portion of FIG. 1 , albeit with an indication of the effect of actuator movement;
FIG. 5 is a further enlarged view of the FIG. 4 dispenser, but with its cover separated from its main body, and with the actuator shown in its rest position;
FIG. 6 is a view similar to FIG. 4 , but with the cover of the dispenser partially fragmented, and the actuator in its rest position;
FIG. 7 is a view similar to FIG. 6 , but with the actuator shown having driven a pill to its ready position;
FIG. 8 is a perspective view of an alternate embodiment of a dispenser; and
FIG. 9 is a schematic view of an internal cavity thereof. 8 , albeit with the dispenser cover off.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1-3 , numeral 10 refers to the dispenser assembly as installed at a rearward end of a toilet bowl 12 . There is a toilet seat 13 and toilet seat cover or lid 14 . In accordance with the present invention there is also a dispenser 16 mounted on an under/forward side of the toilet seat cover 14 .
The cover 14 is pivotably mounted to the toilet bowl 12 so as to pivot between an at least somewhat upright position as shown in FIGS. 1 and 2 . This position is usually defined by a tank or other wall against which the cover rests. As shown in FIG. 3 , from that position the dispenser 16 may dispense a pill 22 into the toilet bowl 12 if, as shown in FIG. 4 , the pill has previously been positioned in a ready position.
As shown in FIG. 5 (or alternatively FIG. 9 ) the dispenser 16 will store a plurality of solid pills 22 . In FIG. 5 the pills are stacked face-to-face and are disk-like. In FIG. 9 the pills are positioned end-to-end are may be disk-like or spherical.
Referring next to FIGS. 4-7 , the dispenser 16 has a two-part outer housing 24 with a delivery slot 26 therein. There is also an actuator 28 which can drive the lowermost pill 22 from a storage area 30 of the dispenser 16 to a ready position 32 adjacent the delivery slot 26 , in response to a manual force having been applied to the actuator 28 against the pressure of a return spring 34 . After the actuator moves a pill to the ready position 32 , the spring 34 causes the actuator 28 to move back to a rest position.
The actuator 28 is preferably in the form of a slide. The actuator 28 may also contain a lock (not shown) which can, when activated, inhibit use of the actuator 28 to move a pill 22 to the ready position. For example, the actuator could be rotatable such that projection 35 moves away from a driving position if desired.
When the toilet cover 14 is pivoted into the essentially horizontal position 20 , the dispenser 16 is moved down into an essentially horizontal position above the toilet bowl 12 . Once the dispenser 16 is in this position, the pill 22 in the ready position is automatically dispensed into the toilet bowl 12 as gravity drives the pill 22 out the delivery slot 26 .
In this manner, a user can determine when cleaning chemicals are to be automatically dispensed into the toilet bowl 12 . For example, if the actuator is not used, no pill will be in the ready position, and no pill will be dispensed.
As shown in FIG. 5 , the pills 22 can be stored in a cartridge unit. This can be separated from the dispenser 16 when the pills have all been dispensed from the dispenser 16 . Hence, only the cartridge unit need be disposed of.
Referring next to FIGS. 8-9 , an alternative embodiment of the present invention is shown. In this embodiment, the dispenser 16 has a somewhat different external housing shape 36 . More importantly, here there is no actuator. Rather, there is a serpentine waiting path 38 within the dispenser 16 , with the pills 22 stored in a row abutting each other in edge-to-edge fashion (somewhat like an automated vendor path). Here, the next pill simply rolls to the ready position after one is dispensed and the lid is raised.
To provide greater control over dispensing, one could provide a threaded cap or snap cap (not shown) over the dispensing hole 51 if one didn't want vending. Hence, in this embodiment, the positioning to the ready position occurs via gravity, and a manual cap placement prevents vending if desired.
The pills 22 may be any conventional toilet bowl cleaning tablet material, or other treating formulations. Most preferably, the pills will contain surfactants, bleaches, disinfectants, fragrances, builders, colorants and/or any combination thereof. The cleaning chemicals should preferably be capable of removing lime and unwanted stains. The exact formulation is not critical except that the pill should not be so sticky as to impede dispensing.
For example, a pill could be based on one of the denture cleanser tablet formulations described in U.S. Pat. No. 5,384,062 (e.g. perborate based with a talc lubricant and a polytetrafluoroethylene compression aid).
While embodiments of the present invention have been described, other embodiments of the invention are within the spirit and scope of this disclosure. For example, some consumers may prefer a smoother underside to the lid (e.g. for the perceived benefit of using the lid as a back rest, or for aesthetic reasons). Hence, the dispenser may be housed within the lid with only a small outlet slot visible to consumers along the underside. With this embodiment, the actuator could be positioned elsewhere on the lid.
Further, while it is desirable that there be automatic inhibition of dispensing when the lid is in the up position, the means of achieving this (while also permitting dispensing when the lid is down) may vary from embodiment to embodiment. Hence, the claims, when presented, should not be construed as being limited to just the disclosed preferred embodiments.
INDUSTRIAL APPLICABILITY
The present invention provides devices for delivering toilet treating chemicals to toilet bowls in a consumer-controlled fashion.
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Toilet bowl treating/cleaning assemblies are provided. In one form the toilet seat lid has mounted on it a dispenser in a fashion so that pivoting of the lid assists in controlling dispensing of a solid pill containing a treating chemical. Also, structures are provided to avoid dispensing when a consumer determines that bowl treatment is not needed, and to facilitate dispensing in response to manual activation.
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BACKGROUND OF THE INVENTION
The present invention is directed to an assembling device for web-like workpieces consisting of superposed and glued layers. The device is used as a double-facer of a machine producing corrugated board and on which the layers continuously run in the form of a web.
For an appropriate presentation the invention will be described particularly in relation with a so-called double-facer.
As a rule, corrugated board is composed of a first so-called single-faced board layer consisting of fluted paper glued on a flat liner paper. This first layer is then assembled also by gluing with a second layer, which second layer may be either a second flat outer liner paper so as to form a so-called double-faced corrugated board or the second layer may be a second single-faced board to which an added outer liner paper is also applied so as to form a so-called double wall corrugated board. Corrugated boards with triple fluting is also produced in a similar way. A machine, which produces the corrugated board and is also called a corrugator, usually comprises a first so-called wet end in which the board is actually made and a second so-called dry end in which the web-like board is cut into individual sheets which are then piled up.
The first so-called wet end begins with a station, which is generally called a single-facer in the industry. In this station, the paper to be fluted after previously heating up and moistening runs through between two corrugating rolls themselves heated with steam. The flutes are shaped and held against the lower corrugating roll due to the action of either fingers or with regard to the cylinder outer means with which provides an overpressure or inner means in which a low pressure or vacuum is applied. An adjacent gluing drum applies glue on the tips of the flutes and then a preheated liner sheet is applied under pressure and with heat input against the tips by a pressing drum which is adjacent to the gluing drum and which pressing drum is also heated with steam. The glue will them immediately adhere owing to the effect of pressure and heat input.
The single-face corrugated board which is thus shaped then runs into a so-called glue unit which applies glue on the outer tips of the flutes which are still exposed. About one third of the water content in the glue amalgamates with the solid matter to form an adhesive whereas the remaining two thirds is freely available water which increases the paper moisture at this stage.
The single-face board thus provided with glue then runs on into a so-called double facer where it is joined with a second liner paper or else with the second single-faced intermediary board itself which is joined with a liner. The purpose of this double-facer is thus to put and hold together the various layers by simultaneously providing the necessary heat for the gelling of the glue and the removal of the moisture, to carry the amalgamated board forward, while continuing the elimination of moisture, and to hold the board flat throughout the cool-down process.
Considering the presence of the flutes, it is easy to understand that it is not possible to apply high pressure in the double-facer between the board layers, which is different than the prior action in the single-facer. This pressure reduction requires less heat input and thus much more time to get the glue gelled. In other words, at this stage of manufacture, the board travels continuously in the form of a web and the longer setting time will require an increase in the length of the double-facer.
The double-facer consists generally of a heating section as well as a pulling or second section onto also called a cooling section.
In the heating or first section the various layers destined to make up the corrugated board are applied on a number of heating plates with the help of an upper belt traveling through the whole station. An application pressure is exerted by the pressure roller acting on the upper belt. Another way of subjecting the various layers to pressure consist in using blowing cases or plenums which are arranged above the lower path of the upper belt and exert a uniform pressure on the whole upper side of the belt and, thus, on the various layers of the corrugated board. As a rule, the first section has 18 to 24 heating plates arranged in three or four sub-assemblies with each plate which extends perpendicular to the travel line of the corrugated board being produced. The plates have a lengthwise dimension slightly greater than the usable width of the corrugator and thus a width of about 50 cm. The plates are steam heated for each assembly.
A subsequent pulling section includes a lower drive belt which is driven synchronously with the upper belt. The corrugated boards are held between the two belts in order to be pulled out by the friction from the heating section.
The major draw back of such a double-facer is its considerable length. In fact, the production speed wanted determines not only the number of heating places required for the heat transfer into the corrugated board in order to cause the glue to gel and the water surplus contained in the corrugated board to be removed but also the length of the pulling section on account of the frictional forces involved. Similarly, the mechanical power required for the drive of the belt also becomes very significant. In addition, impurities, which are accumulating gradually in the joining areas between the plates, can reach such a point that they will scratch the lower liner of the corrugated board. This is all the more undesirable if the liner has undergone an embellishment treatment such as a coating or printing.
Finally, if it appears appropriate to use blowing cases or plenums in the heating section, the upper belt should almost certainly consist of a felt in order to insure sufficient friction between the upper belt and the corrugated web. In fact, a mesh belt has the advantage of letting water-laden air through the belt to provide uniformly applied pressures on the corrugated web; however, it does not build up any force of adherence between the belt and the corrugated board that would be sufficient for ensuring traction. However, such a force of adhesion or traction is generally useful for pulling the corrugated board through the device. On conventional devices, the considerable length of the successive heating plates entails a friction-type braking force to such an amount that all forces of adherence or traction appearing between the upper and lower belts and between the upper belt and the corrugated board will be necessary for transportation. A decease of the force of adherence between the upper belt and the corrugated board in the area of the blowing cases, which decrease would result from the use of a mesh belt, is thus inadmissable. On the other hand, the felt belt has the serious drawback of gathering moisture instead of letting it pass. So if so-called heavy corrugated boards are to be produced, the accumulation of moisture is likely to jeopardize production speed.
U.S. Pat. No. 3,217,425, a double-facer is proposed as an assembling device which does not use heating plates but comprises a lower belt acting together with supporting rollers and an upper belt running under the pressure rollers as well as under the upper nozzles, which are blowing hot air onto the corrugated board being produced. The air is immediately sucked into the lower pressure case. However, considering the excessive heating and drying performance of the device, the corrugated board has a tendency to warp quickly at the outlet depending on the excessive and insufficient moisture of the single-face board and/or of the various layers at the inlet. It is, thus, foreseen to put into operation a complex device for measuring the amount of warping at the outlet and providing a control for the preheating means, which act individually on each layer at the inlet. Nonetheless, the stabilization of this loop due to the counter-reaction is rather difficult to achieve and includes the secondary risk of overheating the glue prior to the layers being assembled.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a double-facer, which ensues only that the layers are put into and held in firm contact with one another without any crushing but also ensues that the heating and drying of the corrugated board is properly regulated to ensure the setting of the glue as well as sufficient cooling so that the corrugated board will run out flat both lengthwise and crosswise. Because of the flatness of the surface condition of the lower paper liner, i.e. the outer liner on the package made of the corrugated board, the assembling device according to the present invention also ensures a better performance than the devices of the prior art.
To accomplish these goals, the present invention is directed to a device for assembling a web-like workpiece consisting of superimposed and glued layers and which device is designed for being used as a double-facer for producing corrugated board on which the layers continuously run in the form of a web. The device includes along a line for the traveling direction of the web a first so-called heating section followed by a second drying and pulling section followed by a third cooling and driving section, conveying means including an upper belt having an inlet drum and an outlet drum with the inlet drum being arranged adjacent to an inlet to the first section and the outlet drum being arranged adjacent the end of the third cooling and driving section, a lower belt extending around an inlet drum situated between the heating section and the beginning of the second drying and pulling section and an outlet drum arranged at the outlet of the cooling and driving section, wherein the upper belt and the lower belt are mesh belts. The first heating section consists essentially of a single heating plate provided with a smooth horizontal surface and a first blowing case positioned above the upper belt for directing a pulsating air through the upper belt downward on the heating plate, said second drying and pulling section including a row of upper slot shaped parallel extending nozzles in an upper suction case disposed above the upper surface of a lower run of the upper belt and having plurality of transverse pressure rollers disposed between adjacent nozzles engaging the belt surface, and a plurality of supporting rollers positioned under the run of the lower belt to support the lower belt in a plane, and the third cooling and driving section comprising extension of the upper suction case from the second to the third section and including a plurality of pressure rollers acting on the upper belt and supporting rollers supporting the run of the lower belt. Preferably, the second section also includes a row of lower slot shaped transverse nozzles situated underneath and extending perpendicular to the track of the corrugated board for blowing hot air through the lower belt onto the assembly of layers, and a suction box being applied around the lower nozzles and extending into the third section.
The above structure allows diminishing the length of the friction surface of the heating section and, hence, the force of friction in the heating section. Numerous practical tests undertaken in this field have shown that the heating plate with the length of one to two meters in the running direction would be sufficient to ensure proper setting of the glue as well as a plane surface of the outer liner. The reduction of friction due to the reduction of length provides either a reduction in the connected power for a given yield or an unchange length and connected power with a higher yield.
Moreover, the relatively small length of the heating plate in comparison with the length of the driving section allows the use of the mesh belt which as known from the prior art enables improve removal of moisture and thereby the discarding of the production speed limit which is due to the accumulation of moisture in the belt if the latter consist of felt.
Other advantages and features of the invention should be really apparent from the following description of the preferred embodiment, the drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of this device according to the present invention with portions broken away for purposes of illustration; and
FIG. 2 is a cross-sectional view taken along plane II--II of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The principles of the present invention are particularly useful when incorporated in an assembly device generally indicated 1000 in FIG. 1. The assembly device 1000 assembles a so-called single-faced layer 20, which has flutes extending therefrom with a so-called liner 30 to form a web 10 of corrugated board.
The assembling device 1000 as illustrated in FIG. 1 includes three successive though considerably distinct sections. The first of these sections is a so-called heating section which enables a gelling of the glue previously applied on the tips of the flutes of the upper or so-called single-face layer 20 which is destined to be assembled with the lower so-called liner layer 30 as the two layers 20 and 30 travel through in the form of webs. A second section is a so-called drying and pulling section which enables the extraction of the residue moisture from the two layers 20 and 30. This section contributes also at least partially to the conveyance of the corrugated board web 10 being produced. The third section is a so-called driving and cooling section which acts on the two assembled layers 20 and 30 in the form of the corrugated board web 10 which is being produced.
The first section consists essentially of a lower single horizontal plate 250 which is situated beneath the track of the webs 20 and 30 and includes an upper blow casing 150 which is positioned above the two webs 20 and 30 and also the heating plate 250. The heating plate 250 can be a cast or steel case which is fed with steam. Its crosswise dimensions is slightly larger than the useable width of the corrugator and has a width of about 2 meters. To avoid any deformation, the plate has an inner reinforcement with the form of ribs or braces acting as protuberances which will increase the heat exchange between the plate and the steam in the case. The upper surface of this plate is a perfect plane to allow the avoidance of any accumulations of impurities which would be likely to scratch the surface of the lower liner 30. Machining and fitting of this single heating plate are possible due to its dimensions. The purpose of the upper blowing case 150 is to blow air downward onto the upper side of the single face layer 20 in order to fully flatten the two layers 20 and 30 on the heating plate 250 to form the corrugated board 10.
As shown in FIG. 1, the second section which is a drying and pulling section comprises a row of upper identical nozzles 120 which are arranged to extend crosswise or transverse to the traveling direction of the layer 20 and 30 through the device 1000. The nozzles 120 extend over at least the whole useable width of the corrugator and are arranged to extend parallel to one another and sequentially in the running direction. Preferably, the drying section should comprise a row of lower nozzles 220 which are symmetrically arranged in correspondence with the upper nozzles 120. All the nozzles 120 and 220 have a common oblique parallelepipedic shape which means that if the upper nozzle 120 are considered, they are higher at the end from which the air arrives so that the cross-section decreases as the distance from the air source for the nozzle increases. The lower base of the upper nozzles 120 have a truncated shape arranged downwardly which on account of the ensuing decremental air blowing section, will engender a slight speed increment to the out flowing air. The upper nozzles 120 are located in an upper suction case 130 whereas the lower nozzles 220 are located in a lower suction case 230.
As illustrated in FIG. 2, the air supplied to the nozzles 120 and 220 is from a source including a duct 50 which is connected by a number of supply pipes 52 to the lower corresponding nozzles 220 and by a number of upper supply pipes 54 to the upper nozzles 120. The hot air is thus blown down against the upper surface of the single-face layer 20 and upwardly against the lower surface of the liner layer 30 before being sucked upward by the upper casing 130 and downward by the lower casing 230. The two cases 130 and 230 are provided with ducts 62 and 64, respectively, which are connected to an outlet 60 which extends to a single pump (not shown) for creating a sufficient low pressure or vacuum within each of the cases 130 and 230.
As illustrated in FIG. 1, it will become obviously that the upper casing 130 extends towards the right-hand side, i.e. down stream beyond the row of upper nozzles 120 and this extension makes the upper part of the third so-called driving and cooling section. Similarly, the lower casing 230 also extends towards the right-hand side beyond the row of lower nozzles 220. The inner side of the straight part of the cases 130 and 230 have also low pressure due to the action of the outlet suction pump, so that fresh air will stream through the horizontal slots subsisting at the level of the board 10 between the two cases before escaping through the duct 60.
The section also includes a plurality of upper pressure rollers 115 which extend parallel to the nozzles 120 and are positioned between these nozzles and a plurality of lower pressure rollers 215 which are supporting rollers and extend between the nozzles 220. The third section which is the driving and cooling section includes lower support rollers 210 and upper pressure rollers 110.
To convey the webs 20 and 30 and also the corrugated board through the device 1000, the device includes conveyor means which include an upper continuous belt 100 and a lower continuous belt 200.
As illustrated in FIG. 1, an inlet end to find by an inlet drum 106 is positioned adjacent the inlet of the blowing case 150. The upper belt 100 passing around the drum 106 and travels first between the blowing case 150 and the heating plate 250 and then into the second so-called drying section which has the upper nozzles 120 and also under the first pressure rollers 115 which are located between the upper nozzles 120 and arranged parallel to them. The upper belt 100 then proceeds to travel into the third so-called driving and cooling section which has additional pressure rollers 110, which extend parallel to each other and transverse to the direction of movement of the web. At the outlet of the third chamber the upper belt 100 passes around another drum 105, which can be the driving drum. In order to take up any stretching, a first upper stretching roll pair 107a is located adjacent to the drum 105 and in the path returning to the first inlet drum 106, the belt is supported by a second upper roll pair 107b situated mainly in the center of the device as well as an upper guide roller 108 which is positioned mainly above the blowing case 150.
The lower belt 200 extends between an inlet drum 206 and a lower outlet drum 205. The inlet drum 206 is situated following the heating plate 250 so that the lower belt 200 only engages the webs 20 and 30 after they have passed through the first section. The belt 200 runs over the lower nozzles 220 and is supported above these nozzles by the rollers 215 of the second section and then passes into the third section where it is supported by the rollers 210. As it leaves the third section, it passes over the lower outlet drive drum 205, which is a driving drum, and is taken through a pair of lower tightening rolls 207 before being directed towards the front end of the device to pass over a guiding roll 208 which is positioned adjacent a beginning of the lower exhaust or suction casing 230.
In operation, the single-face layer 20 has passed through a so-called glue unit so that the flutes have been moistened with an adhesive and then with the liner paper or layer 30 is introduced into the first section where the blowing case 150 applies a force of air to the layer 20 and forces the layer 20 against the layer 30 and also the layer 30 against the heating plate 220 to cause the gelling and setting of the glue to form corrugated board 10. The assembled corrugated board 10 is still wet and is taken in an inlet of the second station between the upper belt 100, which is forced downwardly by the pressure of the roller 115 and then the rollers 110 while the lower belt 200 is held in place by the supporting rollers 215 and also the rollers 210 in the third station. Since the only frictional forces to be overcome are those which are generated in the first heating section, the useful pulling track length, which corresponds to the length of the upper side of the lower belt 200, can be reduced to a considerably lesser dimension than in comparison to the previously used devices.
Since the belts 100 and 200 have a mesh structure, the air blown from the nozzles passes easily therethrough. Thereby the air stream gets loaded with humidity and is immediately absorbed by the suction cases 130 and 230. Attention should be drawn to the fact that the useful suction area at the level of the corrugated board 10 comprises the spaces between the nozzles minus the contact portion of the rollers 115 and 210 which portions are aerodynamically rather insignificant.
In addition, the board 10 undergoes a drying process and a cooling down simultaneously in the third section and is reliably held flat between the two belts 100 and 200. The belts 100 and 200 are guided in this section by the rollers 110 and 210.
Considering the high drying power, which is ensured by the nozzles and the suction cases, it may be appropriate to use only one row of such nozzles, i.e. the upper ones or the lower ones. Similarly, it is also envisioned to arrange a regulating shutter valve 120a in the inlets 54 for each of the upper nozzles 120 and a regulating shutter valve 220a in the inlet 52 of each of the lower nozzles 220. By utilizing these shutters, which form valve means, it is possible to shut off some of the nozzles in certain instances as desired.
Numerous other modifications can be added to the device mentioned above without impairing the essential idea of the invention. For instance, infra-red radiation, ultra-violet radiation, microwave radiation or electron-beam radiation and combinations of these various systems can be substituted for the hot air used for heating and drying. The heating system thus allows a differential heating input crosswise to the web in order to cope with possible transverse moisture variations appearing in the form of streaks in the traveling direction of the various layers.
Although various minor modifications may be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent granted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.
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A device, which assembles web-like workpieces consisting of superimposed glued layers to form a web of corrugated board material, includes three sections with a first section having a single heating plate and an upper blowing case, a second section including upper and lower transverse nozzles, as well as upper and lower suction chambers and a third section including the extension of the upper and lower suction chambers. The device includes a conveying arrangement which has an upper continuous mesh belt passing through the first, second and third sections, and a lower belt passing only through the second and third sections.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No. 09/486,302, filed Oct. 16, 2000, which is the National Stage of PCT/US98/18597, filed Sep. 4, 1998, which claims priority to U.S. Ser. No. 08/926,313, filed Sep. 5, 1997, now U.S. Pat. No. 5,968,829, issued Oct. 19, 1999, each of which are incorporated herein by reference in their entireties.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates to isolation of human central nervous system stem cells, and methods and media for proliferating, differentiating and transplanting them.
BACKGROUND OF THE INVENTION
[0003] During development of the central nervous system (“CNS”), multipotent precursor cells, also known as neural stem cells, proliferate, giving rise to transiently dividing progenitor cells that eventually differentiate into the cell types that compose the adult brain. Stem cells (from other tissues) have classically been defined as having the ability to self-renew (i.e., form more stem cells), to proliferate, and to differentiate into multiple different phenotypic lineages. In the case of neural stem cells this includes neurons, astrocytes and oligodendrocytes. For example, Potten and Loeffler (Development, 110:1001, 1990) define stem cells as “undifferentiated cells capable of a) proliferation, b) self-maintenance, c) the production of a large number of differentiated functional progeny, d) regenerating the tissue after injury, and e) a flexibility in the use of these options.”
[0004] These neural stem cells have been isolated from several mammalian species, including mice, rats, pigs and humans. See, e.g., WO 93/01275, WO 94/09119, WO 94/10292, WO 94/16718 and Cattaneo et al., Mol. Brain Res., 42, pp. 161-66 (1996), all herein incorporated by reference.
[0005] Human CNS neural stem cells, like their rodent homologues, when maintained in a mitogen-containing (typically epidermal growth factor or epidermal growth factor plus basic fibroblast growth factor), serum-free culture medium, grow in suspension culture to form aggregates of cells known as “neurospheres”. In the prior art, human neural stem cells have doubling rates of about 30 days. See, e.g., Cattaneo et al., Mol. Brain Res., 42, pp. 161-66 (1996). Upon removal of the mitogen(s) and provision of a substrate, the stem cells differentiate into neurons, astrocytes and oligodendrocytes. In the prior art, the majority of cells in the differentiated cell population have been identified as astrocytes, with very few neurons (<10%) being observed.
[0006] There remains a need to increase the rate of proliferation of neural stem cell cultures. There also remains a need to increase the number of neurons in the differentiated cell population. There further remains a need to improve the viability of neural stem cell grafts upon implantation into a host.
SUMMARY OF THE INVENTION
[0007] This invention provides novel human central nervous system stem cells, and methods and media for proliferating, differentiating and transplanting them. In one embodiment, this invention provides novel human stem cells with a doubling rate of between 5-10 days, as well as defined growth media for prolonged proliferation of human neural stem cells. In another embodiment, this invention provides a defined media for differentiation of human neural stem cells so as to enrich for neurons, oligodendrocytes, astrocytes, or a combination thereof. The invention also provides differentiated cell populations of human neural stem cells that provide previously unobtainable large numbers of neurons, as well as astrocytes and oligodendrocytes. This invention also provides novel methods for transplanting neural stem cells that improve the viability of the graft upon implantation in a host.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 shows a representation of spheres of proliferating 9FBr human neural stem cells (passage 6) derived from human forebrain tissue.
[0009] [0009]FIG. 2, Panel A, shows a growth curve for a human neural stem cell line designated 6.5Fbr cultured in (a) defined media containing EGF, FGF and leukemia inhibitory factor (“LIF”) (shown as closed diamonds), and (b) the same media but without LIF (shown as open diamonds); Panel B shows a growth curve for a human neural stem cell line designated 9Fbr cultured in (a) defined media containing EGF, FGF and LIF (shown as closed diamonds), and (b) the same media but without LIF (shown as open diamonds); Panel C shows a growth curve for a human neural stem cell line designated 9.5Fbr cultured in (a) defined media containing EGF, FGF and LIF (shown as closed diamonds), and (b) the same media but without LIF (shown as open diamonds); Panel D shows a growth curve for a human neural stem cell line designated 10.5Fbr cultured in (a) defined media containing EGF, FGF and leukemia inhibitory factor (“LIF”) (shown as closed diamonds), and (b) the same media but without LIF (shown as open diamonds).
[0010] [0010]FIG. 3 shows a growth curve for a human neural stem cell line designated 9Fbr cultured in (a) defined media containing EGF and basic fibroblast growth factor (“bFGF”) (shown as open diamonds), and (b) defined media with EGF but without bFGF (shown as closed diamonds).
[0011] [0011]FIG. 4 shows a graph of cell number versus days in culture for an Mx-1 conditionally immortalized human glioblast line derived from a human neural stem cell line. The open squares denote growth in the presence of interferon, the closed diamonds denote growth in the absence of interferon.
DETAILED DESCRIPTION OF THE INVENTION
[0012] This invention relates to isolation, characterization, proliferation, differentiation and transplantation of CNS neural stem cells.
[0013] The neural stem cells described and claimed in the applications may be proliferated in suspension culture or in adherent culture. When the neural stem cells of this invention are proliferating as neurospheres, human nestin antibody may be used as a marker to identify undifferentiated cells. The proliferating cells show little GFAP staining and little β-tubulin staining (although some staining might be present due to diversity of cells within the spheres).
[0014] When differentiated, most of the cells lose their nestin positive immunoreactivity. In particular, antibodies specific for various neuronal or glial proteins may be employed to identify the phenotypic properties of the differentiated cells. Neurons may be identified using antibodies to neuron specific enolase (“NSE”), neurofilament, tau, beta-tubulin, or other known neuronal markers. Astrocytes may be identified using antibodies to glial fibrillary acidic protein (“GFAP”), or other known astrocytic markers. Oligodendrocytes may be identified using antibodies to galactocerebroside, O4, myelin basic protein (“MBP”) or other known oligodendrocytic markers. Glial cells in general may be identified by staining with antibodies, such as the M2 antibody, or other known glial markers.
[0015] In one embodiment the invention provides novel human CNS stem cells isolated from the forebrain. We have isolated 4 neural stem cell lines from human forebrain, all of which exhibit neural stem cell properties; namely, the cells are self renewing, the cells proliferate for long periods in mitogen containing serum free medium, and the cells, when differentiated, comprise a cell population of neurons, astrocytes and oligodendrocytes. These cells are capable of doubling every 5-10 days, in contrast with the prior art diencephalon-derived human neural stem cells. Reported proliferation rates of diencephalon-derived human neural stem cells approximate one doubling every 30 days. See Cattaneo et al., Mol. Brain Res., 42, pp. 161-66 (1996).
[0016] Any suitable tissue source may be used to derive the neural stem cells of this invention. Neural stem cells can be induced to proliferate and differentiate either by culturing the cells in suspension or on an adherent substrate. See, e.g., U.S. Pat. Nos. 5,750,376 and 5,753,506 (both incorporated herein by reference in their entirety), and prior art medium described therein. Both allografts and autografts are contemplated for transplantation purposes.
[0017] This invention also provides a novel growth media for proliferation of neural stem cells. Provided herein is a serum-free or serum-depleted culture medium for the short term and long term proliferation of neural stem cells.
[0018] A number of serum-free or serum-depleted culture media have been developed due to the undesirable effects of serum which can lead to inconsistent culturing results. See, e.g., WO 95/00632 (incorporated herein by reference), and prior art medium described therein.
[0019] Prior to development of the novel media described herein, neural stem cells have been cultured in serum-free media containing epidermal growth factor (“EGF”) or an analog of EGF, such as amphiregulin or transforming growth factor alpha (“TGF-α”), as the mitogen for proliferation. See, e.g., WO 93/01275, WO 94/16718, both incorporated herein by reference. Further, basic fibroblast growth factor (“bFGF”) has been used, either alone, or in combination with EGF, to enhance long term neural stem cell survival.
[0020] The improved medium according to this invention, which contains leukemia inhibitory factor (“LIF”), markedly and unexpectedly increases the rate of proliferation of neural stem cells, particularly human neural stem cells.
[0021] We have compared growth rates of the forebrain-derived stem cells described herein in the presence and absence of LIF; unexpectedly we have found that LIF dramatically increases the rate of cellular proliferation in almost all cases.
[0022] The medium according to this invention comprises cell viability and cell proliferation effective amounts of the following components:
[0023] (a) a standard culture medium being serum-free (containing 0-0.49% serum) or serum-depleted (containing 0.5-5.0% serum), known as a “defined” culture medium, such as Iscove's modified Dulbecco's medium (“IMDM”), RPMI, DMEM, Fischer's, alpha medium, Leibovitz's, L-15, NCTC, F-10, F-12, MEM and McCoy's;
[0024] (b) a suitable carbohydrate source, such as glucose;
[0025] (c) a buffer such as MOPS, HEPES or Tris, preferably HEPES;
[0026] (d) a source of hormones including insulin, transferrin, progesterone, selenium, and putrescine;
[0027] (e) one or more growth factors that stimulate proliferation of neural stem cells, such as EGF, bFGF, PDGF, NGF, and analogs, derivatives and/or combinations thereof, preferably EGF and bFGF in combination;
[0028] (f) LIF
[0029] Standard culture media typically contains a variety of essential components required for cell viability, including inorganic salts, carbohydrates, hormones, essential amino acids, vitamins, and the like. We prefer DMEM or F-12 as the standard culture medium, most preferably a 50/50 mixture of DMEM and F-12. Both media are commercially available (DMEM-Gibco 12100-046; F-12-Gibco 21700-075). A premixed formulation is also commercially available (N2-Gibco 17502-030). It is advantageous to provide additional glutamine, preferably at about 2 mM. It is also advantageous to provide heparin in the culture medium. Preferably, the conditions for culturing should be as close to physiological as possible. The pH of the culture medium is typically between 6-8, preferably about 7, most preferably about 7.4. Cells are typically cultured between 30-40° C., preferably between 32-38° C., most preferably between 35-37° C. Cells are preferably grown in 5% CO 2 . Cells are preferably grown in suspension culture.
[0030] In one exemplary embodiment, the neural stem cell culture comprises the following components in the indicated concentrations:
Component Final Concentration 50/50 mix of DMEM/F-12 0.5-2.0 X, preferably 1 X glucose 0.2-1.0%, preferably 0.6% w/v glutamine 0.1-10 mM, preferably 2 mM NaHCO 3 0.1-10 mM, preferably 3 mM HEPES 0.1-10 mM, preferably 5 mM apo-human transferrin 1-1000 μg/ml, preferably 100 μg/ml (Sigma T-2252) human insulin (Sigma I-2767) 1-100, preferably 25 μg/ml putrescine (Sigma P-7505) 1-500, preferably 60 μM selenium (Sigma S-9133) 1-100, preferably 30 nM progesterone (Sigma P-6149) 1-100, preferably 20 nM human EGF (Gibco 13247-010) 0.2-200, preferably 20 ng/ml human bFGF (Gibco 13256-029) 0.2-200, preferably 20 ng/ml human LIF (R&D Systems 250-L) 0.1-500, preferably 10 ng/ml heparin (Sigma H-3149) 0.1-50, preferably 2 μg/ml CO 2 preferably 5%
[0031] Serum albumin may also be present in the instant culture medium—although the present medium is generally serum-depleted or serum-free (preferably serum-free), certain serum components which are chemically well defined and highly purified (>95%), such as serum albumin, may be included.
[0032] The human neural stem cells described herein may be cryopreserved according to routine procedures. We prefer cryopreserving about one to ten million cells in “freeze” medium which consists of proliferation medium (absent the growth factor mitogens), 10% BSA (Sigma A3059) and 7.5% DMSO. Cells are centrifuged. Growth medium is aspirated and replaced with freeze medium. Cells are resuspended gently as spheres, not as dissociated cells. Cells are slowly frozen, by, e.g., placing in a container at −80° C. Cells are thawed by swirling in a 37° C. bath, resuspended in fresh proliferation medium, and grown as usual.
[0033] In another embodiment, this invention provides a differentiated cell culture containing previously unobtainable large numbers of neurons, as well as astrocytes and oligodendrocytes. In the prior art, typically the differentiated human diencephalon-derived neural stem cell cultures formed very few neurons (i.e., less than 5-10%). According to this methodology, we have routinely achieved neuron concentrations of between 20% and 35% (and much higher in other cases) in differentiated human forebrain-derived neural stem cell cultures. This is highly advantageous as it permits enrichment of the neuronal population prior to implantation in the host in disease indications where neuronal function has been impaired or lost.
[0034] Further, according to the methods of this invention, we have achieved differentiated neural stem cell cultures that are highly enriched in GABA-ergic neurons. Such GABA-ergic neuron enriched cell cultures are particularly advantageous in the potential therapy of excitotoxic neurodegenerative disorders, such as Huntington's disease or epilepsy.
[0035] In order to identify the cellular phenotype either during proliferation or differentiation of the neural stem cells, various cell surface or intracellular markers may be used.
[0036] When the neural stem cells of this invention are proliferating as neurospheres, we contemplate using human nestin antibody as a marker to identify undifferentiated cells. The proliferating cells should show little GFAP staining and little β-tubulin staining (although some staining might be present due to diversity of cells within the spheres).
[0037] When differentiated, most of the cells lose their nestin positive immunoreactivity. In particular, antibodies specific for various neuronal or glial proteins may be employed to identify the phenotypic properties of the differentiated cells. Neurons may be identified using antibodies to neuron specific enolase (“NSE”), neurofilament, tau, β-tubulin, or other known neuronal markers. Astrocytes may be identified using antibodies to glial fibrillary acidic protein (“GFAP”), or other known astrocytic markers. Oligodendrocytes may be identified using antibodies to galactocerebroside, O4, myelin basic protein (“MBP”) or other known oligodendrocytic markers.
[0038] It is also possible to identify cell phenotypes by identifying compounds characteristically produced by those phenotypes. For example, it is possible to identify neurons by the production of neurotransmitters such as acetylcholine, dopamine, epinephrine, norepinephrine, and the like.
[0039] Specific neuronal phenotypes can be identified according to the specific products produced by those neurons. For example, GABA-ergic neurons may be identified by their production of glutamic acid decarboxylase (“GAD”) or GABA. Dopaminergic neurons may be identified by their production of dopa decarboxylase (“DDC”), dopamine or tyrosine hydroxylase (“TH”). Cholinergic neurons may be identified by their production of choline acetyltransferase (“ChAT”). Hippocampal neurons may be identified by staining with NeuN. It will be appreciated that any suitable known marker for identifying specific neuronal phenotypes may be used.
[0040] The human neural stem cells described herein can be genetically engineered or modified according to known methodology. The term “genetic modification” refers to the stable or transient alteration of the genotype of a cell by intentional introduction of exogenous DNA. DNA may be synthetic, or naturally derived, and may contain genes, portions of genes, or other useful DNA sequences. The term “genetic modification” is not meant to include naturally occurring alterations such as that which occurs through natural viral activity, natural genetic recombination, or the like.
[0041] A gene of interest (i.e., a gene that encodes a biologically active molecule) can be inserted into a cloning site of a suitable expression vector by using standard techniques. These techniques are well known to those skilled in the art. See, e.g., WO 94/16718, incorporated herein by reference.
[0042] The expression vector containing the gene of interest may then be used to transfect the desired cell line. Standard transfection techniques such as calcium phosphate co-precipitation, DEAE-dextran transfection, electroporation, biolistics, or viral transfection may be utilized. Commercially available mammalian transfection kits may be purchased from e.g., Stratagene. Human adenoviral transfection may be accomplished as described in Berg et al. Exp. Cell Res., 192, pp. (1991). Similarly, lipofectamine-based transfection may be accomplished as described in Cattaneo, Mol. Brain Res., 42, pp. 161-66 (1996).
[0043] A wide variety of host/expression vector combinations may be used to express a gene encoding a biologically active molecule of interest. See, e.g., U.S. Pat. No. 5,545,723, herein incorporated by reference, for suitable cell-based production expression vectors.
[0044] Increased expression of the biologically active molecule can be achieved by increasing or amplifying the transgene copy number using amplification methods well known in the art. Such amplification methods include, e.g., DHFR amplification (see, e.g., Kaufman et al., U.S. Pat. No. 4,470,461) or glutamine synthetase (“GS”) amplification (see, e.g., U.S. Pat. No. 5,122,464, and European published application EP 338,841), all herein incorporated by reference.
[0045] In another embodiment, the genetically modified neural stem cells are derived from transgenic animals.
[0046] When the neural stem cells are genetic modified for the production of a biologically active substance, the substance will preferably be useful for the treatment of a CNS disorder. We contemplate genetically modified neural stem cells that are capable of secreting a therapeutically effective biologically active molecule in patients. We also contemplate producing a biologically active molecule with growth or trophic effect on the transplanted neural stem cells. We further contemplate inducing differentiation of the cells towards neural cell lineages. The genetically modified neural stem cells thus provide cell-based delivery of biological agents of therapeutic value.
[0047] The neural stem cells described herein, and their differentiated progeny may be immortalized or conditionally immortalized using known techniques. We prefer conditional immortalization of stem cells, and most preferably conditional immortalization of their differentiated progeny. Among the conditional immortalization techniques contemplated are Tet-conditional immortalization (see WO 96/31242, incorporated herein by reference), and Mx-1 conditional immortalization (see WO 96/02646, incorporated herein by reference).
[0048] This invention also provides methods for differentiating neural stem cells to yield cell cultures enriched with neurons to a degree previously unobtainable. According to one protocol, the proliferating neurospheres are induced to differentiate by removal of the growth factor mitogens and LIF, and provision of 1% serum, a substrate and a source of ionic charges (e.g., glass cover slip covered with poly-omithine or extracellular matrix components). The preferred base medium for this differentiation protocol, excepting the growth factor mitogens and LIF, is otherwise the same as the proliferation medium. This differentiation protocol produces a cell culture enriched in neurons. According to this protocol, we have routinely achieved neuron concentrations of between 20% and 35% in differentiated human forebrain-derived neural stem cell cultures.
[0049] According to a second protocol, the proliferating neurospheres are induced to differentiate by removal of the growth factor mitogens, and provision of 1% serum, a substrate and a source of ionic charges (e.g., glass cover slip covered with poly-ornithine or extracellular matrix components), as well as a mixture of growth factors including PDGF, CNTF, IGF-1, LIF, forskolin, T-3 and NT-3. The cocktail of growth factors may be added at the same time as the neurospheres are removed from the proliferation medium, or may be added to the proliferation medium and the cells pre-incubated with the mixture prior to removal from the mitogens. This protocol produces a cell culture highly enriched in neurons and enriched in oligodendrocytes. According to this protocol, we have routinely achieved neuron concentrations of higher than 35% in differentiated human forebrain-derived neural stem cell cultures.
[0050] The presence of bFGF in the proliferation media unexpectedly inhibits oligodendrocyte differentiation capability. bFGF is trophic for the oligodendrocyte precursor cell line. Oligodendrocytes are induced under differentiation conditions when passaged with EGF and LIF in proliferating media, without bFGF.
[0051] The human stem cells of this invention have numerous uses, including for drug screening, diagnostics, genomics and transplantation. Stem cells can be induced to differentiate into the neural cell type of choice using the appropriate media described in this invention. The drug to be tested can be added prior to differentiation to test for developmental inhibition, or added post-differentiation to monitor neural cell-type specific reactions.
[0052] The cells of this invention may be transplanted “naked” into patients according to conventional techniques, into the CNS, as described for example, in U.S. Pat. Nos. 5,082,670 and 5,618,531, each incorporated herein by reference, or into any other suitable site in the body.
[0053] In one embodiment, the human stem cells are transplanted directly into the CNS. Parenchymal and intrathecal sites are contemplated. It will be appreciated that the exact location in the CNS will vary according to the disease state.
[0054] Implanted cells may be labeled with bromodeoxyuridine (BrdU) prior to transplantation. We have observed in various experiments that cells double stained for a neural cell marker and BrdU in the various grafts indicate differentiation of BrdU stained stem cells into the appropriate differentiated neural cell type (see Example 9). Transplantation of human forebrain derived neural stem cells to the hippocampus produced neurons that were predominantly NeuN staining but GABA negative. The NeuN antibody is known to stain neurons of the hippocampus. GABA-ergic neurons were formed when these same cell lines were transplanted into the striatum. Thus, transplanted cells respond to environmental clues in both the adult and the neonatal brain.
[0055] According to one aspect of this invention, provided herein is methodology for improving the viability of transplanted human neural stem cells. In particular, we have discovered that graft viability improves if the transplanted neural stem cells are allowed to aggregate, or to form neurospheres prior to implantation, as compared to transplantation of dissociated single cell suspensions. We prefer transplanting small sized neurospheres, approximately 10-500 μm in diameter, preferably 40-50 μm in diameter. Alternatively, we prefer spheres containing about 5-100, preferably 5-20 cells per sphere. We contemplate transplanting at a density of about 10,000-1,000,000 cells per μl, preferably 25,000-500,000 cells per μl.
[0056] The cells may also be encapsulated and used to deliver biologically active molecules, according to known encapsulation technologies, including microencapsulation (see, e.g., U.S. Pat. Nos. 4,352,883; 4,353,888; and 5,084,350, herein incorporated by reference), (b) macroencapsulation (see, e.g., U.S. Pat. Nos. 5,284,761, 5,158,881, 4,976,859 and 4,968,733 and published PCT patent applications W092/19195, WO 95/05452, each incorporated herein by reference).
[0057] If the human neural stem cells are encapsulated, we prefer macroencapsulation, as described in U.S. Pat. Nos. 5,284,761; 5,158,881; 4,976,859; 4,968,733; 5,800,828 and published PCT patent application WO 95/05452, each incorporated herein by reference. Cell number in the devices can be varied; preferably each device contains between 10 3 -10 9 cells, most preferably 10 5 to 10 7 cells. A large number of macroencapsulation devices may be implanted in the patient; we prefer between one to 10 devices.
[0058] In addition, we also contemplate “naked” transplantation of human stem cells in combination with a capsular device wherein the capsular device secretes a biologically active molecule that is therapeutically effective in the patient or that produces a biologically active molecule that has a growth or trophic effect on the transplanted neural stem cells, or that induces differentiation of the neural stem cells towards a particular phenotypic lineage.
[0059] The cells and methods of this invention may be useful in the treatment of various neurodegenerative diseases and other disorders. It is contemplated that the cells will replace diseased, damaged or lost tissue in the host. Alternatively, the transplanted tissue may augment the function of the endogenous affected host tissue. The transplanted neural stem cells may also be genetically modified to provide a therapeutically effective biologically active molecule.
[0060] Excitotoxicity has been implicated in a variety of pathological conditions including epilepsy, stroke, ischemia, and neurodegenerative diseases such as Huntington's disease, Parkinson's disease and Alzheimer's disease. Accordingly, neural stem cells may provide one means of preventing or replacing the cell loss and associated behavioral abnormalities of these disorders. Neural stem cells may replace cerebellar neurons lost in cerebellar ataxia, with clinical outcomes readily measurable by methods known in the medical arts.
[0061] Huntington's disease (HD) is an autosomal dominant neurodegenerative disease characterized by a relentlessly progressive movement disorder with devastating psychiatric and cognitive deterioration. HD is associated with a consistent and severe atrophy of the neostriatum which is related to a marked loss of the GABAergic medium-sized spiny projection neurons, the major output neurons of the striatum. Intrastriatal injections of excitotoxins such as quinolinic acid (QA) mimic the pattern of selective neuronal vulnerability seen in HD. QA lesions result in motor and cognitive deficits which are among the major symptoms seen in HD. Thus, intrastriatal injections of QA have become a useful model of HD and can serve to evaluate novel therapeutic strategies aimed at preventing, attenuating, or reversing neuroanatomical and behavioral changes associated with HD. Because GABA-ergic neurons are characteristically lost in Huntington's disease, we contemplate treatment of Huntington's patients by transplantation of cell cultures enriched in GABA-ergic neurons derived according to the methods of this invention.
[0062] Epilepsy is also associated with excitotoxicity. Accordingly, GABA-ergic neurons derived according to this invention are contemplated for transplantation into patients suffering from epilepsy.
[0063] We also contemplate use of the cells of this invention in the treatment of various demyelinating and dysmyelinating disorders, such as Pelizaeus-Merzbacher disease, multiple sclerosis, various leukodystrophies, post-traumatic demyelination, and cerebrovascular (CVS) accidents, as well as various neuritis and neuropathies, particularly of the eye. We contemplate using cell cultures enriched in oligodendrocytes or oligodendrocyte precursor or progenitors, such cultures prepared and transplanted according to this invention to promote remyelination of demyelinated areas in the host.
[0064] We also contemplate use of the cells of this invention in the treatment of various acute and chronic pains, as well as for certain nerve regeneration applications (such as spinal cord injury). We also contemplate use of human stem cells for use in sparing or sprouting of photoreceptors in the eye.
[0065] The cells and methods of this invention are intended for use in a mammalian host, recipient, patient, subject or individual, preferably a primate, most preferably a human.
[0066] The following examples are provided for illustrative purposes only, and are not intended to be limiting.
EXAMPLES
Example 1
Media for Proliferating Neural Stem Cells
[0067] Proliferation medium was prepared with the following components in the indicated concentrations:
Component Final Concentration 50/50 mix of DMEM/F-12 1 X glucose 0.6% w/v glutamine 2 mM NaHCO 3 3 mM HEPES 5 mM apo-human transferrin (Sigma T-2252) 100 μg/ml human insulin (Sigma I-2767) 25 μg/ml putrescine (Sigma P-7505) 60 μM selenium (Sigma S-9133) 30 nM progesterone (Sigma P-6149) 20 nM human EGF (Gibco 13247-010) 20 ng/ml human bFGF (Gibco 13256-029) 20 ng/ml human LIF (R&D Systems 250-L) 10 ng/ml heparin (Sigma H-3149) 2 μg/ml
Example 2
Isolation of Human CNS Neural Stem Cells
[0068] Sample tissue from human embryonic forebrain was collected and dissected in Sweden and kindly provided by Huddinje Sjukhus. Blood samples from the donors were sent for viral testing. Dissections were performed in saline and the selected tissue was placed directly into proliferation medium (as described in Example 1). Tissue was stored at 4° C. until dissociated. The tissue was dissociated using a standard glass homogenizer, without the presence of any digesting enzymes. The dissociated cells were counted and seeded into flasks containing proliferation medium. After 5-7 days, the contents of the flasks are centrifuged at 1000 rpm for 2 min. The supernatant was aspirated and the pellet resuspended in 200 μl of proliferation medium. The cell clusters were triturated using a P200 pipetman about 100 times to break up the clusters. Cells were reseeded at 75,000-100,000 cells/ml into proliferation medium. Cells were passaged every 6-21 days depending upon the mitogens used and the seeding density. Typically these cells incorporate BrdU, indicative of cell proliferation. For T75 flask cultures (initial volume 20 ml), cells are “fed” 3 times weekly by addition of 5 ml of proliferation medium. We prefer Nunc flasks for culturing.
[0069] Nestin Staining for Proliferating Neurospheres
[0070] We stained for nestin ( a measure of proliferating neurospheres) as follows. Cells were fixed for 20 min at room temperature with 4% paraformaldehyde. Cells were washed twice for 5 min with 0.1 M PBS, pH 7.4. Cells were permeabilized for 2 min with 100% EtOH. The cells were then washed twice for 5 min with 0.1 M PBS. Cell preparations were blocked for 1 hr at room temperature in 5% normal goat serum (“NGS”) diluted in 0.1M PBS, pH 7.4 and 1% Triton X-100 (Sigma X-100) for 1 hr at room temperature with gentle shaking. Cells were incubated with primary antibodies to human nestin (from Dr. Lars Wahlberg, Karolinska, Sweden, rabbit polyclonal used at 1:500) diluted in 1% NGS and 1% Triton X-100 for 2 hr at room temperature. Preparations were then washed twice for 5 min with 0.1 M PBS. Cells were incubated with secondary antibodies (pool of GAM/FITC used at 1:128, Sigma F-0257; GAR/TRITC used at 1:80, Sigma T-5268) diluted in 1% NGS and 1% Triton X-100 for 30 min at room temperature in the dark. Preparations are washed twice for 5 min with 0.1 M PBS in the dark. Preparations are mounted onto slides face down with mounting medium (Vectashield Mounting Medium, Vector Labs., H-1000) and stored at 4° C.
[0071] [0071]FIG. 1 shows a picture of proliferating spheres (here called “neurospheres”) of human forebrain derived neural stem cells. We evaluated proliferation of 4 lines of human forebrain derived neural stem cells in proliferation medium as described above with LIF present of absent.
[0072] As FIG. 2 shows, in three of the four lines (6.5 Fbr, 9Fbr, and 10.5FBr), LIF significantly increased the rate of cell proliferation. The effect of LIF was most pronounced after about 60 days in vitro.
[0073] We also evaluated the effect of bFGF on the rate of proliferation of human forebrain-derived neural stem cells. As FIG. 3 shows, in the presence of bFGF, the stem cells proliferation was significantly enhanced.
Example 3
Differentiation of Human Neural Stem Cells
[0074] In a first differentiation protocol, the proliferating neurospheres were induced to differentiate by removal of the growth factor mitogens and LIF, and provision of 1% serum, a substrate and a source of ionic charges(e.g., glass cover slip covered with poly-ornithine).
[0075] The staining protocol for neurons, astrocytes and oligodendrocytes was as follows:
[0076] β-tubulin Staining for Neurons
[0077] Cells were fixed for 20 min at room temperature with 4% paraformaldehyde. Cells were washed twice for 5 min with 0.1 M PBS, pH 7.4. Cells were permeabilized for 2 min with 100% EtOH. The cells were then washed twice for 5 min with 0.1 M PBS. Cell preparations were blocked for 1 hr at room temperature in 5% normal goat serum (“NGS”) diluted in 0.1M PBS, pH 7.4. Cells were incubated with primary antibodies to β-tubulin (Sigma T-8660, mouse monoclonal; used at 1:1,000) diluted in 1% NGS for 2 hr at room temperature. Preparations were then washed twice for 5 min with 0.1 M PBS. Cells were incubated with secondary antibodies (pool of GAM/FITC used at 1:128, Sigma F-0257; GAR/TRITC used at 1:80, Sigma T-5268) diluted in 1% NGS for 30 min at room temperature in the dark. Preparations are washed twice for 5 min with 0.1 M PBS in the dark. Preparations are mounted onto slides face down with mounting medium (Vectashield Mounting Medium, Vector Labs., H-000) and stored at 4° C.
[0078] In some instances we also stain with DAPI (a nuclear stain), as follows. Coverslips prepared as above are washed with DAPI solution (diluted 1:1000 in 100% MeOH, Boehringer Mannheim, #236 276). Coverslips are incubated in DAPI solution for 15 min at 37° C.
[0079] O4 Staining for Oligodendrocytes
[0080] Cells were fixed for 10 min at room temperature with 4% paraformaldehyde. Cells were washed three times for 5 min with 0.1 M PBS, pH 7.4. Cell preparations were blocked for 1 hr at room temperature in 5% normal goat serum (“NGS”) diluted in 0.1M PBS, pH 7.4. Cells were incubated with primary antibodies to O4 (Boehringer Mannheim #1518 925, mouse monoclonal; used at 1:25) diluted in 1% NGS for 2 hr at room temperature. Preparations were then washed twice for 5 min with 0.1 M PBS. Cells were incubated with secondary antibodies, and further processed as described above for β-tubulin.
[0081] GFAP Staining for Astrocytes
[0082] Cells were fixed for 20 min at room temperature with 4% paraformaldehyde. Cells were washed twice for 5 min with 0.1 M PBS, pH 7.4. Cells were permneabilized for 2 min with 100% EtOH. The cells were then washed twice for 5 min with 0.1 M PBS. Cell preparations were blocked for 1 hr at room temperature in 5% normal goat serum (“NGS”) diluted in 0. 1M PBS, pH 7.4. Cells were incubated with primary antibodies to GFAP (DAKO Z 334, rabbit polyclonal; used at 1:500) diluted in 1% NGS for 2 hr at room temperature. Preparations were then washed twice for 5 min with 0.1 M PBS. Cells were incubated with secondary antibodies, and further processed as described above for β-tubulin.
[0083] This differentiation protocol produced cell cultures enriched in neurons as follows:
% of neurons % % β- that are Cell Line Passage GFAP Positive tubulin positive GABA positive 6.5 FBr 5 15 37 20 9 FBr 7 52 20 35 10.5 FBr 5 50 28 50
[0084] We also evaluated the ability of a single cell line to differentiate consistently as the culture aged (i.e., at different passages), using the above differentiation protocol. The data are as follows:
% of neurons % % β- that are Cell Line Passage GFAP Positive tubulin positive GABA positive 9 FBr 7 53 20.4 ND 9 FBr 9 ND 20.3 34.5 9 FBr 15 62 17.9 37.9
[0085] We conclude from these data that cells will follow reproducible differentiation patterns irrespective of passage number or culture age.
Example 4
Differentiation of Human Neural Stem Cells
[0086] In a second differentiation protocol, the proliferating neurospheres were induced to differentiate by removal of the growth factor mitogens and LIF, and provision of 1% serum, a substrate (e.g., glass cover slip or extracellular matrix components), a source of ionic charges (e.g., poly-ornithine) as well as a mixture of growth factors including 10 ng/ml PDGF A/B, 10 ng/ml CNTF, 10 ng/ml IGF-1, 10 gM forskolin, 30 ng/ml T3, 10 ng/ml LIF and 1 ng/ml NT-3. This differentiation protocol produced cell cultures highly enriched in neurons (i.e., greater than 35% of the differentiated cell culture) and enriched in oligodendrocytes.
Example 5
Differentiation of Human Neural Stem Cells
[0087] In a third differentiation protocol, cell suspensions were initially cultured in a cocktail of hbFGF, EGF, and LIF, were then placed into altered growth media containing 20 ng/mL hEGF (GIBCO) and 10 ng/mL human leukemia inhibitory factor (hLIF) (R&D Systems), but without hbFGF. The cells initially grew significantly more slowly than the cultures that also contained hbFGF (see FIG. 3). Nonetheless, the cells continued to grow and were passaged as many as 22 times. Stem cells were removed from growth medium and induced to differentiate by plating on poly-omithine coated glass coverslips in differentiation medium supplemented with a growth factor cocktail (hPDGF A/B, hCNTF, hGF-1, forskolin, T3 and hNT-3). Surprisingly, GalC immunoreactivity was seen in these differentiated cultures at levels that far exceeded the number of O4 positive cells seen in the growth factor induction protocol described in Example 4.
[0088] Hence, this protocol produced differentiated cell cultures enrichment in oligodendrocytes. Neurons were only occasionally seen, had small processes, and appeared quite immature.
Example 6
Genectic Modification
[0089] We have conditionally immortalized a glioblast cell line derived from the human neural stem cells described herein, using the Mx-1 system described in WO 96/02646. In the Mx-1 system, the Mx-1 promoter drives expression of the SV40 large T antigen. The Mx-1 promoter is induced by interferon. When induced, large T is expressed, and quiescent cells proliferate.
[0090] Human glioblasts were derived from human forebrain neural stem cells as follows. Proliferating human neurospheres were removed from proliferation medium and plated onto poly-ornithine plastic (24 well plate) in a mixture of N2 with the mitogens EGF, bFGF and LIF, as well as 0.5% FBS. 0.5 ml of N2 medium and 1% FBS was added. The cells were incubated overnight. The cells were then transfected with p318 (a plasmid containing the Mx-1 promoter operably linked to the SV 40 large T antigen) using Invitrogen lipid kit (lipids 4 and 6). The transfection solution contained 6 μl/ml of lipid and 4 μl/ml DNA in optiMEM medium. The cells were incubated in transfection solution for 5 hours. The transfection solution was removed and cells placed into N2 and 1% FBS and 500 U/ml A/D interferon. The cells were fed twice a week. After ten weeks cells were assayed for large T antigen expression. The cells showed robust T antigen staining at this time. As FIG. 4 shows, cell number was higher in the presence of interferon than in the absence of interferon.
[0091] Large T expression was monitored using immunocytochemistry as follows. Cells were fixed for 20 min at room temperature with 4% paraformaldehyde. Cells were washed twice for 5 min with 0.1 M PBS, pH 7.4. Cells were permeabilized for 2 min with 100% EtOH. The cells were then washed twice for 5 min with 0.1 M PBS. Cell preparations were blocked for 1 hr at room temperature in 5% normal goat serum (“NGS”) diluted in 0.1M PBS, pH 7.4. Cells were incubated with primary antibodies to large T antigen (used at 1:10) diluted in 1% NGS for 2 hr at room temperature. We prepared antibody to large T antigen in house by culturing PAB 149 cells and obtaining the conditioned medium. Preparations were then washed twice for 5 min with 0.1 M PBS. Cells were incubated with secondary antibodies (goat-anti-mouse biotinylated at 1:500 from Vector Laboratories, Vectastain Elite ABC mouse IgG kit, PK-6102) diluted in 1% NGS for 30 min at room temperature. Preparations are washed twice for 5 min with 0.1 M PBS. Preparations are incubated in ABC reagent diluted 1:500 in 0.1 M PBS, pH 7.4 for 30 min at room temperature. Cells are washed twice for 5 min in 0.1 M PBS, pH 7.4, then washed twice for 5 min in 0.1 M Tris, pH 7.6. Cells are incubated in DAB (nickel intensification) for 5 min at room temperature. The DAB solution is removed, and cells are washed three to five times with dH20. Cells are stored in 50% glycerol/50% 0.1 M PBS, pH 7.4.
Example 7
Encapsulation
[0092] If the human neural stem cells are encapsulated, then the following procedure may be used:
[0093] The hollow fibers are fabricated from a polyether sulfone (PES) with an outside diameter of 720 m and a wall thickness of a 100 m (AKZO-Nobel Wüppertal, Germany). These fibers are described in U.S. Pat. Nos. 4,976,859 and 4,968,733, herein incorporated by reference. The fiber may be chosen for its molecular weight cutoff. We sometimes use a PES#5 membrane which has a MWCO of about 280 kd. In other studies we use a PES#8 membrane which has a MWCO of about 90 kd.
[0094] The devices typically comprise:
[0095] 1) a semipermeable poly (ether sulfone) hollow fiber membrane fabricated by AKZO Nobel Faser AG;
[0096] 2) a hub membrane segment;
[0097] 3) a light cured methacrylate (LCM) resin leading end; and
[0098] 4) a silicone tether.
[0099] The semipermeable membrane used typically has the following characteristics:
Internal Diameter 500 + 30 m Wall Thickness 100 + 15 m Force at Break 100 + 15 cN Elongation at Break 44 + 10% Hydraulic Permeability 63 + 8 (ml/min m 2 mmHg) nMWCO (dextrans) 280 + 20 kd
[0100] The components of the device are commercially available. The LCM glue is available from Ablestik Laboratories (Newark, Del.); Luxtrak Adhesives LCM23 and LCM24). The tether material is available from Specialty Silicone Fabricators (Robles, Calif.). The tether dimensions are 0.79 mm OD×0.43 mm ID×length 202 mm. The morphology of the device is as follows: The inner surface has a permselective skin. The wall has an open cell foam structure. The outer surface has an open structure, with pores up to 1.5 m occupying 30+5% of the outer surface.
[0101] Fiber material is first cut into 5 cm long segments and the distal extremity of each segment sealed with a photopolymerized acrylic glue (LCM-25, ICI). Following sterilization with ethylene oxide and outgassing, the fiber segments are loaded with a suspension of between 10 4 -10 7 cells, either in a liquid medium, or a hydrogel matrix (e.g., a collagen solution (Zyderm®), alginate, agarose or chitosan) via a Hamilton syringe and a 25 gauge needle through an attached injection port. The proximal end of the capsule is sealed with the same acrylic glue. The volume of the device contemplated in the human studies is approximately 15-18 1.
[0102] A silicone tether (Specialty Silicone Fabrication, Taunton, Ma.) (ID: 690 m; OD: 1.25 mm) is placed over the proximal end of the fiber allowing easy manipulation and retrieval of the device.
Example 8
Transplantation of Neural Stem Cells
[0103] We have transplanted human neural stem cells into rat brain and assessed graft viability, integration, phenotypic fate of the grafted cells, as well as behavioral changes associated with the grafted cells in lesioned animals.
[0104] Transplantation was performed according to standard techniques. Adult rats were anesthetized with sodium pentobarbitol (45 mg/kg, i.p.) And positioned in a Kopf stereotaxic instrument. A midline incision was made in the scalp and a hole drilled for the injection of cells. Rats received implants of unmodified, undifferentiated human neural stem cells into the left striatum using a glass capillary attached to a 10 μl Hamilton syringe. Each animal received a total of about 250,000-500,000 cells in a total volume of 2 μl. Cells were transplanted 1-2 days after passaging and the cell suspension was made up of undifferentiated stem cell clusters of 5-20 cells. Following implantation, the skin was sutured closed.
[0105] Animals were behaviorally tested and then sacrificed for histological analysis.
Example 9
Intraventricular EGF Delivery With Transplantation of Neural Stem Cells
[0106] Approximately 300,000 neural stem cells were transplanted as small neurospheres into the adult rat striatum close to the lateral ventricle using standard techniques. During the same surgery session, osmotic minipumps releasing either EGF (400 ng/day) or vehicle were also implanted in the striatum. The rats received EGF over a period of 7 days at a flow rate of 0.5 μL/hr, resulting in the delivery of 2.8 μg EGF in total into the lateral ventricle of each animal. Subsets of implanted rats were additionally immunosuppressed by i.p. cyclosporin injections (10 mg/kg/day). During the last 16 hours of pump infusion, the animals received injections of BrdU every three hours (120 mg/kg).
[0107] One week after transplantation, the animals were perfused with 4% paraformaldehyde and serial sections cut on a freezing microtome at 30 μm thickness. Brain sections were stained for astrocytes, oligodendrocytes, neuron, and undifferentiated progenitor cell markers. Minimal migration was demonstrated in adult CNS in the absence of EGF. Excellent survival of the 7 day old grafts was seen in rats receiving EGF as demonstrated by M2 immunoreactivity, and grafts in EGF-treated animals were more extensive than in animals treated with vehicle alone. Furthermore, proliferation of host cells was observed upon EGF treatment. Animals receiving BrdU injections before sacrifice demonstrated an increased number of dividing cells in the treated ventricle, but not the adjoining ventricles.
Example 10
Treatment of Syringomyelia
[0108] Primary fetal transplants have been used to obliterate the syrinx formed around spinal cord injuries in patients. The neural stem cells described in this invention are suitable for replacement, because only a structural function would be required by the cells. Neural stem cells are implanted in the spinal cord of injured patients to prevent syrinx formation. Outcomes are measured preferably by MRI imaging. Clinical trial protocols have been written and could easily be modified to include the described neural stem cells.
Example 11
Treatment of Neurodegenerative Disease Using Progent of Human Neural Stem Cells Proliferated in vitro
[0109] Cells are obtained from ventral mesencephalic tissue from a human fetus aged 8 weeks following routine suction abortion which is collected into a sterile collection apparatus. A 2×4×1 mm piece of tissue is dissected and dissociated as in Example 2. Neural stem cells are then proliferated. Neural stem cell progeny are used for neurotransplantation into a blood-group matched host with a neurodegenerative disease. Surgery is performed using a BRW computed tomographic (CT) stereotaxic guide. The patient is given local anesthesia suppiemencea with intravenously administered midazolam. The patient undergoes CT scanning to establish the coordinates of the region to receive the transplant. The injection cannula consists of a 17-gauge stainless steel outer cannula with a 19-gauge inner stylet. This is inserted into the brain to the correct coordinates, then removed and replaced with a 19-gauge infusion cannula that has been preloaded with 30 μl of tissue suspension. The cells are slowly infused at a rate of 3 μl/min as the cannula is withdrawn. Multiple stereotactic needle passes are made throughout the area of interest, approximately 4 mm apart. The patient is examined by CT scan postoperatively for hemorrhage or edema. Neurological evaluations are performed at various post-operative intervals, as well as PET scans to determine metabolic activity of the implanted cells.
Example 12
Genectic Modification of Neural Stem Cell Progeny Using Calcium Phosphate Transfection
[0110] Neural stem cell progeny are propagated as described in Example 2. The cells are then transfected using a calcium phosphate transfection technique. For standard calcium phosphate transfection, the cells are mechanically dissociated into a single cell suspension and plated on tissue culture-treated dishes at 50% confluence (50,000-75,000 cells/cm 2 ) and allowed to attach overnight.
[0111] The modified calcium phosphate transfection procedure is performed as follows: DNA (15-25 μg) in sterile TE buffer (10 mM Tris, 0.25 mM EDTA, pH 7.5) diluted to 440 μl with TE, and 60 μl of 2M CaCl 2 (pH to 5.8 with 1M HEPES buffer) is added to the DNA/TE buffer. A total of 500 μl of 2×HeBS (HEPES-Buffered saline; 275 mM NaCl, 10 mM KCl, 1.4 mM Na 2 HPO 4 , 12 mM dextrose, 40 mM HEPES buffer powder, pH 6.92) is added dropwise to this mix. The mixture is allowed to stand at room temperature for 20 minutes. The cells are washed briefly with 1×HeBS and 1 ml of the calcium phosphate precipitated DNA solution is added to each plate, and the cells are incubated at 37° for 20 minutes. Following this incubation, 10 mls of complete medium is added to the cells, and the plates are placed in an incubator (37° C., 9.5% CO 2 ) for an additional 3-6 hours. The DNA and the medium are removed by aspiration at the end of the incubation period, and the cells are washed 3 times with complete growth medium and then returned to the incubator.
Example 13
Genectic Modification of Neural Stem Cell Progeny
[0112] Cells proliferated as in Examples 2 are transfected with expression vectors containing the genes for the FGF-2 receptor or the NGF receptor. Vector DNA containing the genes are diluted in 0.1×TE (1 mM Tris pH 8.0, 0.1 mM EDTA) to a concentration of 40 μg/ml. 22 μl of the DNA is added to 250 μl of 2×HBS (280 mM NaCl, 10 mM KCl, 1.5 mM Na 2 HPO 4 2H 2 O, 12 mM dextrose, 50 mM HEPES) in a disposable, sterile 5 ml plastic tube. 31 μl of 2M CaCl 2 is added slowly and the mixture is incubated for 30 minutes at room temperature. During this 30 minute incubation, the cells are centrifuged at 800 g for 5 minutes at 40° C. The cells are resuspended in 20 volumes of ice-cold PBS and divided into aliquots of 1×10 7 cells, which are again centrifuged. Each aliquot of cells is resuspended in 1 ml of the DNA-CaCl 2 suspension, and incubated for 20 minutes at room temperature. The cells are then diluted in growth medium and incubated for 6-24 hours at 37° C. in 5%-7% CO 2 . The cells are again centrifuged, washed in PBS and returned to 10 ml of growth medium for 48 hours.
[0113] The transfected neural stem cell progeny are transplanted into a human patient using the procedure described in Example 8 or Example 11, or are used for drug screening procedures as described in the example below.
Example 14
Screening of Drugs or Other Biological Agents for Effects on Multipotent Neural Stem Cells and Neural Stem Cell Progeny
[0114] A. Effects of BDNF on Neuronal and Glial Cell Differentiation and Survival
[0115] Precursor cells were propagated as described in Example 2 and differentiated as described in Example 4. At the time of plating the cells, BDNF was added at a concentration of 10 ng/ml. At 3, 7, 14, and 21 days in vitro (DIV), cells were processed for indirect immunocytochemistry. BrdU labeling was used to monitor proliferation of the neural stem cells. The effects of BDNF on neurons, oligodendrocytes and astrocytes were assayed by probing the cultures with antibodies that recognize antigens found on neurons (MAP-2, NSE, NF), oligodendrocytes (O4, GalC, MBP) or astrocytes (GFAP). Cell survival was determined by counting the number of immunoreactive cells at each time point and morphological observations were made. BDNF significantly increased the differentiation and survival of neurons over the number observed under control conditions. Astrocyte and oligodendrocyte numbers were not significantly altered from control values.
[0116] B. Effects of BDNF on the Differentiation of Neural Phenotypes
[0117] Cells treated with BDNF according to the methods described in Part A were probed with antibodies that recognize neural transmitters or enzymes involved in the synthesis of neural transmitters. These included TH, ChAT, substance P, GABA, somatostatin, and glutamate. In both control and BDNF-treated culture conditions, neurons tested positive for the presence of substance P and GABA. As well as an increase in numbers, neurons grown in BDNF showed a dramatic increase in neurite extension and branching when compared with control examples.
[0118] C. Identification of Growth-Factor Responsive Cells
[0119] Cells were differentiated as described in Example 4, and at 1 DIV approximately 100 ng/ml of BDNF was added. At 1, 3, 6, 12 and 24 hours after the addition of BDNF the cells were fixed and processed for dual label immunocytochemistry. Antibodies that recognize neurons (MAP-2, NSE, NF), oligodendrocytes (O4, GalC, MBP) or astrocytes (GFAP) were used in combination with an antibody that recognizes c-fos and/or other immediate early genes. Exposure to BDNF resulted in a selective increase in the expression of c-fos in neuronal cells.
[0120] D. Effects of BDNF on the Expression of Markers and Regulatory Factors During Proliferation and Differentiation
[0121] Cells treated with BDNF according to the methods described in Part A are processed for analysis of the expression of regulatory factors, FGF-R1 or other markers.
[0122] E. Effects of Chlorpromazine on the Proliferation, Differentiation, and Survival of Growth Factor Generated Stem Cell Progeny
[0123] Chlorpromazine, a drug widely used in the treatment of psychiatric illness, is used in concentrations ranging from 10 ng/ml to 1000 ng/ml in place of BDNF in Examples 14A to 14D above. The effects of the drug at various concentrations on stem cell proliferation and on stem cell progeny differentiation and survival is monitored. Alterations in gene expression and electrophysiological properties of differentiated neurons are determined.
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The invention provides a method for determining the effect of a biological agent comprising contacting a cell culture with a biological agent. The cell culture of the invention contains a culture medium containing one or more preselected growth factors effective for inducing multipotent central nervous system (CNS) neural stem cell proliferation. The cell culture also contains, suspended in the culture medium, human multipotent CNS neural stem cells that are derived from primary CNS neural tissue that have a doubling rate faster than 30 days.
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FIELD OF THE INVENTION
The present invention relates to exercise equipment and particularly to a training apparatus for use by participants in boxing, martial arts and other combat/fighting sports. More specifically the invention relates to a double end training ball or bag that is suspended on a cord or band that extends from a lower surface to an upper surface to allow the double end training ball to be easily adjusted for use by persons of different heights.
BACKGROUND OF THE INVENTION
Combat sports, also known as a combative sports, are competitive contact sports where two combatants fight against each other using certain rules of engagement (usually significantly different from the rules in simulated combats meant for practice or challenge in martial arts), typically with the aim of simulating parts of real hand to hand combat. Boxing, kickboxing, amateur wrestling, and mixed martial arts are examples of combat sports.
Boxing and mixed martial arts (and all other forms of combat sports) typically require a great deal of training in order to develop and hone the fighting skills. A variety of different training techniques and training devices are utilized in combat sport training.
A boxing or mixed martial arts training program must focus on reactive power, power endurance, muscular endurance, anaerobic endurance and aerobic endurance.
The double end bag, also known as the floor-ceiling bag, crazy bag, or the reflex bag, is a training device comprising an inflated ball suspended between two elastic ropes or cords connected at one end of each part of the ropes to the ceiling and floor in a gym or training room and which is capable of moving around easily, providing the athlete with a valuable piece of equipment for accuracy and timing practice.
Currently used double end training balls are connected on diametrically opposite ends to a piece of cord or rope. The cord or rope is typically elastic. The other ends of the cord or rope are connected to the floor and ceiling respectively in a room, typically a gym or training room. The double end ball is suspended between the cord or rope at a height that permits a boxing or mixed martial arts trainee to punch and jab at the ball. In order to adjust the height of the ball from the floor and ceiling, knots are typically tied at various positions along the cords such that adding and removing knots will lengthen and shorten the cords so as to raise or lower the position of the ball to accommodate users of different heights.
This method of adjusting the ball height is cumbersome and time consuming. A novel double end training ball and an easier and faster method of adjusting the height of a double end training ball is described herein.
The foregoing discussion is presented solely to provide a better understanding of the nature of the problems confronting the art and should not be construed in any way as an admission as to prior art nor should the citation of any reference herein be construed as an admission that such reference constitutes “prior art” to the instant application.
SUMMARY OF THE INVENTION
The present invention provides a height adjustable double end training ball or bag. The terms “ball” and “bag” are used interchangeably throughout this disclosure and are intended to connote the same thing.
In a particular embodiment, the invention provides a double end training ball having an aperture or bore extending through the central diameter of the ball to permit a cord to be passed through such that the ball is slidable on the cord. Restraining elements are attached to the cord above and below the ball or may be integrated within the aperture of the ball, so that the ball is positioned at a desired height along the cord.
Further aspects, features and advantages of the present invention will be better appreciated upon a reading of the detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates one embodiment of a prior art double end training ball;
FIG. 2 is a side view of an embodiment of the adjustable double end ball according to the present invention; and
FIG. 3 is a side cut-away view illustrating the interior of a double end ball.
DESCRIPTION OF THE INVENTION
The present invention provides an adjustable double end training ball and methods of using an adjustable double end training ball.
More specifically, the present disclosure provides a double end ball having a bore or aperture extending through the center diameter of the ball to permit a cord to be extended through the bore. The ball is thus slidable along the cord. One end of the cord is connected, attached or fastened to an upper surface, such as the ceiling in a room where use of the double end training ball is desired, and the other end of the cord is connected, attached or fastened to a lower surface, such as the floor. The position or height of the double end training ball on the cord between the floor and ceiling is rendered adjustable using restraining elements or fastener clips/clamps to secure the ball in the desired position on the cord. The restraining elements may be attached to the cord itself or integrated within the aperture in the ball.
FIG. 1 illustrates a prior art double end ball that is widely used today in training centers and gymnasiums. As shown in FIG. 1 , a double end training ball 2 is retained on a cord 4 that extends between an upper surface 6 and a lower surface 8 . In this prior art embodiment, a first cord section 4 a extends between ball 2 and an upper surface, such as a ceiling 6 and a second cord section 4 b extends between ball 2 and a lower surface, such as a floor 8 . Cords 4 a and 4 b typically comprised of 2 separate lengths 4 a , 4 b . Upper cord 4 a extends from the ceiling to the top of ball 2 and lower cord 4 b is connected to the floor and attaches to the bottom of ball 2 . Ball 2 is shown utilizing “S” hooks 10 , 12 on the top and bottom of the ball 2 to connect and retain ball 2 with the respective parts of cords 4 a and 4 b . In some commercially used double end training balls, the top and bottom side of the ball includes a eyelet 14 , 16 through which the “S” hooks, 10 , 12 connect cord 4 to ball 2 . Additional eyelet screws such as 18 , 20 may, in one embodiment, be screwed into the upper surface (e.g., ceiling) 6 and lower surface (e.g., floor) 8 such that “S” hooks 22 , 24 at the ends of cords 4 a and 4 b respectively, may be connected.
It is noted that the above description of the prior art is not limited to the embodiment described and other methods of connecting cord 4 to the top and bottom of the ball exist. Additionally, several different connection/fastening mechanisms are utilized to connect the opposing ends of the cord to the floor and ceiling respectively.
Athletes training with the double end ball are of different heights and thus need to adjust the height of the ball appropriately to obtain maximum training benefits. Additionally, athletes training with the double end ball may desire to train different types of punches at different times. For example, when an athlete desires to train for punches to the head or upper part of the body, a higher ball height position is necessary. Alternatively when an athlete desires to work on punching to the lower torso area, a lower ball height position is desirable. In prior art double end ball training devices, the height/position of the ball suspended between the upper and lower surface (e.g., floor and ceiling) is adjusted by adding or removing knots (such as those shown as 26 a - 26 d in FIG. 1 ) along the length of cords 4 a and 4 b and as illustrated by the directional arrow 30 .
Tying and untying one or more knots (such as 26 a - 26 d ) on a double end training ball cord can be tedious and time-consuming. The double end training ball of the instant invention eliminates the need for tying and untying knots in the restraining cords and thus facilitates easy and quick positioning of the double end ball on the restraining cords.
FIG. 2 illustrates a novel double end training ball system in accordance with an embodiment of the instant invention. In FIG. 2 , double end training ball 50 comprises a tube 52 that extends through a bore extending through the diameter of ball 50 . FIG. 3 provides a cut-away view of ball 50 in which a bore or aperture 54 is shown extending diametrically from the top of ball 50 to the bottom. Tube 52 is inserted through bore 54 and cord 56 is then passed through tube 52 . Tube 52 may protrude from the bore openings that are located at the top and bottom of ball 50 . In some embodiments, tube 52 is absent and cord 56 is passed directly through bore 54 in ball 50 .
Tube 52 may be rubber, plastic, polyvinyl chloride (PVC), fabric or any appropriately flexible material that can extend through the aperture in ball 50 . The invention is not limited in any way to the composition of tube 52 .
In some embodiments in which ball 50 incorporates a tube 52 , the ball 50 is retained in position and/or height on cord 56 by adding a fastener or restraining element 58 , 60 to tube 52 that protrudes from ball 50 on the top and bottom of the ball. The addition of restraining elements 58 , 60 to tube 52 prevent ball 50 from sliding along cord 56 and allow the easy adjustment and movement of ball 50 on cord 56 along cord 56 as illustrated by directional arrow 62 . Restraining elements 58 , 60 may be detachable or non-detachable clamps (thus permitting ball 50 to be positioned on cord 56 ) such as spring clamps although the invention is not limited in this manner and any type of restraining element may be utilized such that the ball 50 is retained on cord 56 between the restraining elements.
In an alternative embodiment, restraining elements 58 , 60 are integrated on tube 52 . The restraining elements may be hose clamps in which a thin band, typically metallic but not limited thereto, encircles tube 52 and having an attached screw such that when the screw is tightened or loosened, the thin band tightens or loosens around the tube 52 or cord 56 . In another embodiment, not shown, hose clamps or another restraining element may be integrated within aperture 54 .
The double end training ball 50 is typically an inflated rubber ball that is covered with leather, rawhide, felt or any type of covering contemplated by one or ordinary skill in the art. The invention is not, however, limited in the type of ball covering. A fully rubber ball may also be used.
When properly secured and adjusted, the double end training ball bobs, weaves and gyrates on the cord when struck by a user. The constant movement of the double end training ball facilitates speed, reflex and reaction training.
When utilized in a gym or training room, the invention is not limited in the manner in which the cord is attached or connected to an upper and lower surface (e.g., a floor and ceiling) at those respective ends. For example, “S”-type hooks at the end of the cord may be used to connect the cord end to eyelets protruding from the floor and ceiling. Any other temporary and/or permanent connecting mechanism may be used to attach, connect and/or secure the cord ends to the floor and ceiling.
The double end training ball 50 of the instant invention is not limited to use in a gym or training room nor is the invention limited in such a manner wherein cord 56 is secured between a floor and ceiling, such as illustrated in the prior art embodiment of FIG. 1 . While the double end training ball 50 of the instant invention is suitable for installation within a gym or training center, it can also be connected to or secured between arms, such as metal arms, that may be bolted to or removably secured to the floor or ceiling of a room. In an alternative embodiment, the cord of the double end training ball 50 may attach at one end to a tree branch, for example, at its upper end and secured at its lower end to the ground itself or to a securing arm mounted in the ground. In this manner the double end training ball may be utilized outside.
The cord ( 4 in FIG. 1 and 56 in FIG. 2 ) is typically and advantageously an elastic and flexible cord or band that permits the ball to bob and weave and return to its starting position when it is hit, struck or kicked by the training athlete. An exemplary type of cord is bungee cord, or elastic shock cord, which is capable of stretching and then returning to its original form. In one embodiment, elastic shock cord comprises numerous tightly packed, synthetic rubber strands that run the entire length of the cord, and which is typically jacketed with a strong, abrasion resistant, braided nylon casing.
It should be understood that the foregoing description is only illustrative of the present invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variations that fall within the scope of the appended claims.
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A height adjustable double end training ball apparatus for use in boxing, martial arts and other combat/fighting sports training. The double end training ball having an aperture that extends through the center of the ball and having openings at each end of the aperture on the surface of the ball; a cord having a length suitable to extend from an upper surface to a lower surface, such as a floor and ceiling, in a room where the double end training ball will be used, wherein one end of said cord is connected to the upper surface and the opposite end of the cord is connected to the lower surface; and a pair of restraining elements. The double end training ball is secured on the cord via the application of the restraining elements, such as clamps, at a position above and below the ball.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method for passivating a field-effect transistor having at least one source electrode, one drain electrode and one gate electrode. The present invention also relates to a device for detecting at least one substance contained in a fluid stream.
BACKGROUND INFORMATION
[0002] Gas-sensitive field-effect transistors based on semiconductors are increasingly being used in sensor systems. The application of a test species that is to be detected, in this context, for instance, a gas or a liquid, or a gas/liquid mixture, usually leads to a change in the channel impedance, and thus to a change in the current flowing from the source electrode to the drain electrode through the transistor. Such a field-effect transistor is known, for instance, from U.S. Pat. No. 5,698,771. The use of field-effect transistors is possible at up to 800° C. in sensor system applications, if semiconductor substances having a band gap of more than 2 eV, such as gallium nitride or silicon carbide, are used.
[0003] At the working point selected, the channel current of the field-effect transistor is frequently greater by some orders of magnitude (usually 103) than the change in the channel current because of the application of the test species. From this there comes about a great requirement for current measurement. In addition, a problem arises that the offset is able to be influenced by external interferences, so-called noise. Such external interference influences are, for instance, temperature changes or sensor degradation, which lead to changes in the channel current, and are not based on the presence of test species. Based on the given signal-offset ratio, the change in the channel current by interference influences may be of the same order of magnitude, or even greater in the least favorable case, than the change that takes place owing to the presence of test species. Since one cannot exclude these interference influences completely, the error in the measuring signal connected therewith may be large, and may prevent a usable measurement of the test species, in the least favorable case.
[0004] In order to compensate for interference influences and offsets, it is possible, for example, to use a field-effect transistor acting as a reference element, which is insensitive with respect to the substances to be detected. The reference element is preferably identical to the field-effect transistor acting as the measuring sensor with regard to its semiconductor patterns, geometric dimensions and electrical characteristics. Both field-effect transistors have the same zero signal, because of the same electrical characteristics. When the two field-effect transistors are slightly separated spatially, there also exists good heat coupling. This is a given, for instance, in response to the integration of the components on a chip. Because of this, the two field-effect transistors experience the same interference influences. A difference in the channel current of the field-effect transistor acting as measuring sensor may then be attributed only to the presence of the substances that are to be detected.
[0005] The passivating of field-effect transistors so as to make them into reference elements is accomplished according to the related art in a semiconductor process, with the aid of dielectric layers. These are generally deposited using thin-film techniques. However, such a passivating layer may, under certain circumstances, influence the electrical characteristics of the field-effect transistor. Thus, for example, stresses at the boundary layer between the passivating layer and the layer below it, in the case of piezoelectric semiconductor substances, such as gallium nitride, may lead to a change in the field-effect transistor channel. In addition, dielectric passivating layers frequently have electron states which are able to store loads, and are therefore able to influence the electric field under the gate electrode.
[0006] In addition, the passivating of a field-effect transistor used as a reference element on an integrated chip is very costly. Thus, process technology restrictions do not permit complete lateral patterning of the passivation, for example, and, on the other hand, for example, process parameters, such as high temperatures during the depositing of the passivation, damage the chemically sensitive gate of the measuring sensor. For this reason, field-effect transistors acting as a reference element and field-effect transistors acting as a measuring sensor have to be processed separately from one another. Under certain circumstances, this may lead to the field-effect transistors no longer being identical, possibly having different electrical characteristics.
SUMMARY OF THE INVENTION
[0007] In an example method of the present invention for passivating a semiconductor component having at least one chemosensitive electrode, at least the chemosensitive electrode is blinded by the application of a glass layer or a glass-ceramic layer. The glass layer or glass-ceramic layer may be present in an amorphous, partially crystalline or crystalline state.
[0008] Because of the application of the glass layer or the glass-ceramic layer, the chemosensitive electrode of the semiconductor component becomes insensitive to substances that are to be detected, and thus prevent substances present in the fluid stream from interacting with the chemosensitive electrode of the semiconductor component. Such semiconductor components may be used particularly as reference elements for eliminating interference influences in devices for detecting substances in a fluid stream.
[0009] An advantage of applying a glass layer or a glass-ceramic layer to the chemosensitive electrode is that the semiconductor component acting as a reference element may have an identical construction with respect to the semiconductor patterning, the geometric dimensions, the construction of the gate stack as well as the electrical characteristics as the semiconductor component used as the measuring sensor. Because of the identical construction, differences in the channel current of the semiconductor component acting as the measuring sensor and the semiconductor component acting as the reference element, may now be attributed only to the presence of substances that are to be detected. In this case, measuring does not take place with the aid of a current change of a single semiconductor component, but with the aid of the difference of the channel current between the semiconductor component acting as the measuring sensor and the semiconductor component acting as the reference element.
[0010] In an example embodiment of the present invention, the application of the glass layer or the glass-ceramic layer to at least the chemosensitive electrode of the semiconductor component, for the purpose of blinding it, i.e., to make the chemosensitive electrode insensitive to the influence of substances in a fluid stream, takes place, for example, by applying a suspension containing glass powder dispersed in a solvent to the chemosensitive electrode. The solvent is subsequently evaporated and the glass powder is melted. Additional components, that are perhaps contained in the suspension, and that do not evaporate, are burned off by the high temperatures required to melt the glass. In this way, a glass film remains on the chemosensitive electrode of the semiconductor component which is free of organic occlusions. The glass powder preferably includes glass that melts at a temperature in the range of 400 to 800° C. The melting temperature is, however, above the later operating temperature of the semiconductor component, so as to avoid having the glass layer melt again during the operation of the semiconductor component. The softening temperature of the glass is preferably more than 50° C. higher than the operating temperature of the semiconductor component. In order not to damage the substances of the semiconductor component or rather the semiconductor component during the melting of the glass, it is preferred that one select a glass having as low a melting temperature as possible.
[0011] The melting of the glass preferably takes place at a heating rate of up to 100 K/s, a holding time in the range of 0 to 60 minutes and a cooling rate of up to 50 K/s.
[0012] The glass powder or the glass-ceramic powder, used to form the glass layer or the glass-ceramic layer, is either free of alkali or contains alkali. One advantageous alkali-free glass powder is silicate glass powder, for example, that contains bismuth, zinc, boron or combinations of these substances, for example, bismuth-boron-zinc silicate glass powder. The advantage of a bismuth-boron-zinc-silicate glass powder is that it already melts at a temperature of approximately 600° C. Alkali and/or alkaline earth-containing glass powder or glass-ceramic powder may be used, for instance, alkali-alkaline earth-boron silicate glass powder.
[0013] Glasses which melt at low temperatures, that is, at temperatures of approximately 600° C., generally almost always contain high proportions of lead oxide or bismuth oxide. Because of the high proportion of lead oxide or bismuth oxide, the glasses are generally more easily reducible than high-melting point glasses rich in silicon oxide. The reduction of the glass takes place, for example, in the presence of carbon monoxide or in response to a reaction with the surface of the semiconductor chip. Since the reduction leads to damage to the glass layer, glasses that contain only a slight proportion of lead oxide or bismuth oxide are preferably used.
[0014] Also available are alkali-alkaline earth boron silicate glasses that melt at low temperatures, but they generally have high thermal coefficients of expansion. The thermal coefficient of expansion of the alkali-alkaline earth boron silicate glass powder is generally higher than the thermal coefficient of expansion of the silicon carbide used for the semiconductor component as semiconductor material. However, the thermal coefficient of expansion may be adjusted by the addition of an additive having a thermal coefficient of expansion that is lower than the thermal coefficient of expansion of the alkali-alkaline earth boron silicate glass, for example. Suitable additives are cordierite or lithium-aluminum silicate glass ceramics, for instance. Because of this additive, a glass-ceramic composite is formed by melting and subsequent solidification.
[0015] In an example embodiment of the present invention, in order for the glass not to form cracks if there is a deviation in the thermal coefficient of expansion of the semiconductor material and the glass, it is preferred to form the glass so as to have a small layer thickness. However, in an example embodiment, the layer thickness is big enough so that the glass is sealed from the fluid stream. The layer thickness is therefore preferably in a range of 0.1 to 100 μm, and further preferably in a range of 1 to 50 μm.
[0016] The solvent in which the glass powder is dispersed may be an ester or an alcohol ketone.
[0017] Beside the solvent, the suspension may also contain a binding agent. Suitable binding agents are polymethacrylate or cellulose nitrate, for example.
[0018] Greater viscosity of the suspension may be achieved by using the binding agent. In this way, it is possible, for example, for the suspension to be in the form of a paste. This avoids having the suspension run off the semiconductor component after being applied, and thus taking up an undefined shape, and possibly even covering areas on the semiconductor component that should not be covered by the glass layer.
[0019] The application of the suspension may be made by any suitable printing method, by dispensing it on or by pico-deposition methods. Screen printing or dropping it on are suitable methods for applying the suspension, for example.
[0020] According to an example embodiment, the chemosensitive electrode, which is blinded by the application of the glass layer, is preferably a gate electrode of a field-effect transistor or a diode.
[0021] Example embodiments of the present invention also relate to a device for detecting at least one substance contained in a fluid stream. The device may include at least one semiconductor component acting as a measuring sensor and at least one semiconductor component acting as a reference element, the semiconductor components each having a chemosensitive electrode. In an example embodiment, the chemosensitive electrode of the semiconductor component acting as a reference element is passivated. In an example embodiment, a glass layer is applied at least to the chemosensitive electrode of the semiconductor component acting as reference element, for the passivation.
[0022] Because of the glass layer, interaction of components of a fluid with the semiconductor component, which may thus lead to a measuring signal, as was described above, may be avoided. The semiconductor component, acting as reference element, may be used so as to be able to eliminate interference influences which might act upon the detection device.
[0023] In one preferred specific example embodiment, the semiconductor component acting as reference element and the semiconductor component acting as measuring sensor are developed as an integrated component on a chip. In a particularly preferred example embodiment, the semiconductor component acting as reference element and the semiconductor component acting as measuring sensor have a matching design. Because of the matching design, particularly with respect to the semiconductor patterning, the geometric dimensions, the construction of the gate stack, and the electrical characteristics, both the semiconductor component acting as measuring sensor and the semiconductor component acting as reference element react in the same way to environmental influences, such as fluctuations in the temperature. These interference influences may be eliminated, in an example embodiment of the present invention, by subtraction of the signals of the semiconductor component acting as measuring sensor and the semiconductor component acting as reference element.
[0024] Besides a matching design of the semiconductor component acting as reference element and the semiconductor component acting as measuring sensor, it is alternatively possible according to an example embodiment of the present invention, however, to functionalize only the semiconductor components acting as measuring sensor, for example, but to apply to the semiconductor components acting as reference elements a deviating metallization of the gate electrode, already in the semiconductor process.
[0025] Particularly when the designs of the semiconductor component acting as measuring sensor and the semiconductor component acting as reference element have essentially matching designs, it is possible first to produce the two semiconductor components and, only after the production of the semiconductor components, to passivate the chemosensitive electrode of the semiconductor component acting as reference element by applying the glass layer according to the present invention. For the passivation, an example embodiment of the present invention may require that the glass layer cover, in a gas-tight manner, at least the chemosensitive electrode of the semiconductor component acting as reference element. One may also cover a greater area than the area of the chemosensitive electrode, however. Thus, it is possible, for example, to cover the entire semiconductor component acting as reference element, or even more than the semiconductor component acting as reference element, using the glass layer. If both the semiconductor component acting as measuring sensor and the semiconductor component acting as reference element are processed on a common chip, it should be ensured that the chemosensitive electrode of the semiconductor component acting as measuring sensor does not become covered by the glass layer.
[0026] In an example embodiment of the present invention, the semiconductor component acting as measuring sensor or the semiconductor component acting as reference element is preferably a field-effect transistor or a diode. In the case of gases to be detected, a gas-sensitive field-effect transistor or a gas-sensitive diode may be involved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The drawings illustrate generally, by way of example, but not by way of limitation, an example embodiment of the present invention discussed in detail in the following description.
[0028] FIG. 1 shows a schematic representation of a cross section through a semiconductor component developed according to an example method of the present invention.
DETAILED DESCRIPTION
[0029] According to an example embodiment of the present invention, a semiconductor component 1 generally includes a substrate 3 made of a semiconductor material. In principle, all semiconductor substances that have a bandwidth of more than 2 eV are suitable as the semiconductor material. For example, silicon carbide or gallium nitride are suitable semiconductor substances. ZnO or diamond, for instance, are other suitable semiconductor substances.
[0030] In an example embodiment of the present invention, where the semiconductor component 1 is a field-effect transistor, it includes at least one source electrode 5 and one drain electrode 7 . In an example embodiment, source electrode 5 and drain electrode 7 are enclosed by semiconductor material 3 and have one free surface 9 . Alternatively, however, it is also possible that source electrode 5 and drain electrode 7 are applied onto semiconductor material 3 .
[0031] Platinum, titanium, tantalum, silicides or carbides are suitable as the material for source electrode 5 and drain electrode 7 .
[0032] In the illustrated example embodiment, free surfaces 9 of source electrode 5 and drain electrode 7 and the surface of substrate 3 form an even surface. Shown to be applied to this surface is a dielectric 11 that partially covers source electrode 5 , drain electrode 7 , and substrate 3 lying between the source electrode and drain electrode 7 . Suitable materials for dielectric 11 are oxides such as SiO 2 , Al 2 O 3 , ZrO 2 , nitrides such as Si 3 N 4 or carbides such as SiC.
[0033] An electrically conductive layer 13 is shown to be applied to dielectric 11 . In an example embodiment of the present invention, in the case of a field-effect transistor, electrically conductive layer 13 is a gate electrode 17 .
[0034] Besides the illustrated two-layer construction, made up of dielectric 11 and electrically conductive layer 13 , a design using more than two layers is also possible. Thus, an additional layer made of a dielectric substance and an additional electrically conductive layer may be applied, for example. Furthermore, it is also possible to apply a porous layer, for example, which is catalytically active, and at which chemical reaction is able to take place. Alternatively, it is also possible that electrically conductive layer 13 is developed to be porous, for example. In addition, electrically conductive layer 13 may also contain catalytically active material, at which a chemical reaction can take place. Such a chemical reaction leads to a change in the gate voltage, whereby the presence of a substance, that is to be detected, is able to be determined.
[0035] Semiconductor component 1 used as reference element may additionally include a passivating layer on electrically conductive layer 13 that is used as gate electrode 17 . The passivating layer may have a plurality of material layers, for instance. In general, however, no additional passivating layer is applied onto electrically conductive layer 13 .
[0036] The application of dielectric 11 , electrically conductive layer 13 , and perhaps additional layers may take place by any method known to one skilled in the art and established in semiconductor technology. Suitable methods are, for instance, CVD methods or other micropatternable thin film methods such as vapor depositing and sputtering. If necessary, deposit baking steps may be added, which support a dense sintering of layers 11 and 13 . Alternatively, however, it is also possible to provide a wet-chemical depositing of the material for dielectric substance 11 , electrically conductive layer 13 , and possibly additional layers, for example. A temperature treatment may be given following the wet-chemical depositing. The increased temperature of the temperature treatment results in the evaporation of the volatile solvents on the one hand, and dense sintering of the deposited material of layers 11 and 13 on the other hand. Alternatively, however, it is also possible, for instance, to apply dielectric 11 and electrically conductive layer 13 by a structuring thick layer method such as printing on using a paste, and perhaps a subsequent tempering step.
[0037] According to an example embodiment of the present invention, the passivation of gate electrode 17 formed by dielectric 11 and electrically conductive layer 13 takes place by applying a glass layer or the glass-ceramic layer 15 . In an example embodiment, the glass of glass layer 15 is generally impervious to liquids or gases, so that these two do not reach electrically conductive layer 13 . The application of the glass may be performed by a suitably appropriate method known to one skilled in the art. Thus, the glass for glass layer 15 may particularly be formed by applying a suspension or a paste of a glass powder by suitable printing methods, dispensing or pico-deposition methods. The paste or suspension of the glass powder applied is heated, so that the solvent contained in it evaporates. Subsequently, the paste or suspension is melted by heating at a suitable heating rate and holding time at suitable temperatures, and the organic components used to disperse the glass powder included in the suspension are burnt off. Thus it is possible, for instance, to apply a paste of an organic solvent, polymethacrylate and cellulose nitrate binder and a bismuth-boron-zinc silicate glass powder by screen printing or by dropping it on. According to an example embodiment, the paste is subsequently melted at a heating rate of up to 100 K/s, preferably of up to 50 K/s and a holding time in the range of 0 to 60 min, preferably of 5 to 15 min, at a temperature of 600° C. and a subsequent cooling at a cooling rate of up to 50 K/s. A glass layer 15 develops, which is gas-tight and essentially free of organic residues. The temperature of 600° C. is sufficient, in this context, to burn off the organic components that are contained in the suspension because of the polymethacrylate binder and the cellulose nitrate binder.
[0038] When selecting a suitable glass for glass layer 15 , one should be careful that it has a sufficiently high melting point. Thus, it is preferred that the melting point of the glass be at least 50° C. higher than the temperature for the planned insertion of semiconductor component 1 . On the other hand, one should also be careful that the temperature at which the glass, for glass layer 15 , melts is not too high, so as to prevent degradation of semiconductor component 1 during the melting of the glass for glass layer 15 .
[0039] Semiconductor component 1 , having glass layer 15 , is particularly suitable as reference element for the detection of gases in a gas stream. However, alternatively, for example, liquids in a liquid stream or gases dissolved in a liquid stream are also able to be detected. A semiconductor component 1 used as measuring sensor is additionally required for this, for the detection. In general, field-effect transistors or diodes are used as the semiconductor component 1 .
[0040] Because of the construction, according to the present invention, using the glass layer or glass-ceramic layer 15 for semiconductor component 1 used as the reference element, it is possible to combine semiconductor components 1 , that are essentially designed the same, as, respectively, a measuring sensor and as a reference element. According to an example method of the present invention, to produce this combination, the individual layers for the semiconductor component used as the measuring sensor and the semiconductor component used as the reference element are advantageously applied onto a substrate 3 at the same time. Because of this, one is able to achieve essentially the same layers with respect to their thickness and their design and their patterning. According to the example method, only subsequent to the processing of semiconductor component 1 , i.e., when it is completely constructed, are the gate region of semiconductor component 1 that is used as the reference element (at least dielectric substance 11 and electrically conductive layer 13 ) covered by glass layer 15 . It is also possible, however, to cover completely source electrode 5 and drain electrode 7 of the semiconductor component used as reference element using glass layer 15 . A larger area of substrate 3 may also be covered by glass layer 15 . Only the electrically conductive layer of gate electrode 17 of the semiconductor component used as the measuring sensor must not be covered by glass layer 15 .
[0041] According to an alternative example embodiment of the present invention, it is also possible, in the case of semiconductor component 1 used as the reference element, to use substances for gate electrode 17 different from those of the semiconductor component 1 used as the measuring sensor. However, the design is preferably identical, so that interference signals lead to the same signal, both in the case of the semiconductor component 1 used as the measuring sensor and the semiconductor component 1 used as the reference element.
[0042] The simultaneous production of identical semiconductor components on one chip, of which only some, which are used as reference elements, are provided with glass layer 15 , further has the advantage that they may be produced faster and more cost-effectively by the saving of numerous process steps.
[0043] Besides the field-effect transistor shown as semiconductor component 1 in FIG. 1 , semiconductor component 1 that is passivated using glass layer 15 , may also be any other semiconductor component that has a chemosensitive electrode, and is used for detecting gases. Thus, a chemosensitive electrode of a diode may also be provided with the glass layer, for example.
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The present invention relates to a method for passivating a semiconductor component having at least one chemosensitive electrode that is blinded by the application of a glass layer. The present invention also relates to a device for detecting at least one substance included in a fluid stream, including at least one semiconductor component acting as a measuring sensor as well as at least one semiconductor component acting as a reference element, the semiconductor components each having a chemosensitive electrode, and the chemosensitive electrode of the semiconductor component acting as the reference element being passivated. For the passivation, a glass layer may be applied at least to the chemosensitive electrode of the semiconductor component acting as reference element.
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This application is a continuation of application Ser. No. 08/008,446, filed Jan. 22, 1993, now abandoned.
FIELD OF THE INVENTION
This invention relates to various therapeutic methodologies derived from the recognition that certain abnormal cells present complexes of HLA-C-clone 10 and peptides derived from a molecule referred to as MAGE-1 on their surfaces. In addition, it relates to the ability to identify those individuals diagnosed with conditions characterized by cellular abnormalities whose abnormal cells present this complex.
BACKGROUND AND PRIOR ART
The process by which the mammalian immune system recognizes and reacts to foreign or alien materials is a complex one. An important facet of the system is the T cell response. This response requires that T cells recognize and interact with complexes of cell surface molecules, referred to as human leukocyte antigens ("HLA"), or major histocompatibility complexes ("MHCs"), and peptides. The peptides are derived from larger molecules which are processed by the cells which also present the HLA/MHC molecule. See in this regard see Male et al., Advanced Immunology (J. P. Lipincott Company, 1987), especially chapters 6-10. The interaction of T cell and complexes of HLA/peptide is restricted, requiring a T cell specific for a particular combination of an HLA molecule and a peptide. If a specific T cell is not present, there is no T cell response even if its partner complex is present. Similarly, there is no response if the specific complex is absent, but the T cell is present. This mechanism is involved in the immune system's response to foreign materials, in autoimmune pathologies, and in responses to cellular abnormalities. Recently, much work has focused on the mechanisms by which proteins are processed into the HLA binding peptides. See, in this regard, Barinaga, Science 257: 880 (1992); Fremont et al., Science 257: 919 (1992); Matsumura et al., Science 257: 927 (1992); Latron et al., Science 257: 964 (1992).
The mechanism by which T cells recognize cellular abnormalities has also been implicated in cancer. For example, in PCT application PCT/US92/04354, filed May 22, 1992, published on Nov. 26, 1992, as WO92/20356 and incorporated by reference, a family of genes is disclosed which are processed into peptides which, in turn, are expressed on cell surfaces, and can lead to lysis of the tumor cells by specific CTLs. These genes are referred to as the "MAGE" family, and are said to code for "tumor rejection antigen precursors" or "TRAP" molecules, and the peptides derived therefrom are referred to as "tumor rejection antigens" or "TRAs". See Traversari et al., Immunogenetics 35: 145 (1992); van der Bruggen et al., Science 254: 1643 (1991), for further information on this family of genes.
In U.S. patent application Ser. No. 938,334, the disclosure of which is incorporated by reference, nonapeptides are taught which bind to the HLA-A1 molecule. The reference teaches that given the known specificity of particular peptides for particular HLA molecules, one should expect a particular peptide to bind one HLA molecule, but not others. This is important, because different individuals possess different HLA phenotypes. As a result, while identification of a particular peptide as being a partner for a specific HLA molecule has diagnostic and therapeutic ramifications, these are only relevant for individuals with that particular HLA phenotype. There is a need for further work in the area, because cellular abnormalities are not restricted to one particular HLA phenotype, and targeted therapy requires some knowledge of the phenotype of the abnormal cells at issue.
In a patent application Ser. No. 07/994,923 filed on Dec. 22, 1992 in the name of Boon-Falleur et al., entitled "Method For Identifying Individuals Suffering From a Cellular Abnormality, Some of Whose Abnormal Cells Present Complexes of HLA-A2/Tyrosinase Derived Peptides and Methods for Treating said Individuals", the complex of the title was identified as being implicated in certain cellular abnormalities. The application does not suggest, however, that any other HLA molecules might be involved in cellular abnormalities.
The prior presentation of MAGE-1 by an HLA-A1 molecule, as disclosed supra, also does not suggest that the protein can be presented by another HLA molecule. Thus, it is surprising that the very MAGE molecule presented by HLA-A1 has now been shown to be presented by HLA-C-clone 10. While the prior research is of value in understanding the phenomenon, it in no way prepares the skilled artisan for the disclosure which follows.
BRIEF DESCRIPTION OF THE FIGURE
FIG. 1 depicts experiments involving transfection of COS-7 with coding sequences for MAGE-1 and HLA-C-clone 10.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Example 1
In the experiments which follow, various melanoma cell lines were used. These were obtained from melanoma patients identified as MZ2 and LB73. Cell lines MZ2-MEL.43, MZ2-MEL-3.0, and MZ2-MEL 3.1 are cloned sublines of MZ2-MEL, and are described in Van den Eynde et al., Int. J. Canc. 44: 634 (1989), as well as PCT patent application WO92/20356 (Nov. 26, 1992), both disclosures being incorporated by reference and in their entirety herewith. Cell line LB73-MEL was derived from patient LB73 in the same manner as the other cell lines described herein.
Samples containing mononuclear blood cells were taken from patient MZ2. A sample of the melanoma cell line MZ2-MEL.43 was irradiated, and then contacted to the mononuclear blood cell containing samples. The mixtures were observed for lysis of the melanoma cell lines, this lysis indicating that cytolytic T cells ("CTLs") specific for a complex of peptide and HLA molecule presented by the melanoma cells were present in the sample.
The lysis assay employed was a chromium release assay following Herin et al., Int. J. Cancer 39:390-396 (1987), the disclosure of which is incorporated by reference. The assay, however, is described herein. The target melanoma cells were grown in vitro, and then resuspended at 10 7 cells/ml in DMEM, supplemented with 10 mM HEPES and 30% FCS, and incubated for 45 minutes at 37° C. with 200 μCi/ml of Na( 51 Cr)O 4 . Labelled cells were washed three times with DMEM, supplemented with 10 mM Hepes. These were then resuspended in DMEM supplemented with 10 mM Hepes and 10% FCS, after which 100 ul aliquots containing 10 3 cells were distributed into 96 well microplates. Samples of PBLs were added in 100 ul of the same medium, and assays were carried out in duplicate. Plates were centrifuged for 4 minutes at 100 g, and incubated for four hours at 37° C. in a 5.5% CO 2 atmosphere.
Plates were centrifuged again, and 100 ul aliquots of supernatant were collected and counted. Percentage of 51 Cr release was calculated as follows: ##EQU1## where ER is observed, experimental 51 Cr release, SR is spontaneous release measured by incubating 10 3 labeled cells in 200 ul of medium alone, and MR is maximum release, obtained by adding 100 ul 0.3% Triton X-100 to target cells.
Those mononuclear blood samples which showed high CTL activity were expanded and cloned via limiting dilution, and were screened again, using the same methodology.
These experiments led to the isolation of several CTL clones from patient MZ2 including CTL clone "81/12".
The experiment was repeated as described, using both cell line MZ2-MEL 3.0 and MZ2-MEL 3.1. The results indicated that clone 81/12 recognized both MZ2-MEL.43 and MZ2-MEL 3.0, but not MZ2-MEL 3.1. The antigen being recognized by 81/12 is referred to hereafter as "antigen Bb".
Example 2
In view of prior work, as summarized supra, it was of interest to determine the HLA class 1 profile for patient MZ2. This was determined following standard methodologies, which are now set forth. To obtain cDNA clones coding for the genes of the HLA class 1 molecules of the patients, a cDNA library was prepared, starting with total mRNA extracted from cell line MZ2-MEL.43, using well known techniques not repeated here. The library was inserted into plasmid pcD-SRα, and then screened, using an oligonucleotide probe containing a sequence common to all HLA class 1 genes, i.e.:
5'-ACTCCATGAGGTATTTC-3' (SEQ ID NO: 1)
One clone so identified was clone IC4A7 which, upon sequencing, was found to be functionally equivalent, if not identical to, HLA-C-clone 10, a well known human leukocyte antigen molecule. The sequence of the DNA coding for HLA-C clone 10 is taught by, e.g., Cianetti et al., Immunogenetics 29: 80-91 (1989), and the sequence is available under GENBANK accession number HUMMHCACA. An updated sequence is reported by Zemmour et al., Immunogenetics 37: 239-250 (1993), the disclosure of which is incorporated by reference in its entirety, as is Cianetti et al., supra. The Zemmour sequence is also available in the EMBL sequence bank.
Example 3
It was of interest to determine if the HLA molecule identified supra presented a mage derived tumor rejection antigen, and if the resulting complex of antigen and HLA molecule was recognized by a CTL clone of patient MZ2. To determine this, recipient cells were transfected with cDNA coding HLA-C clone 10, and with one of MAGE-1, MAGE-2, or MAGE-3 cDNA. The MAGE-1 cDNA was inserted into plasmid pcDNA I/Amp, while MAGE-2 and MAGE-3 cDNA were inserted into plasmid pcD-SRα.
Samples of recipient COS-7 cells were seeded, at 15,000 cells/well into tissue culture flat bottom microwells, in Dulbecc's modified Eagles Medium ("DMEM") supplemented with 10% fetal calf serum. The cells were incubated overnight at 37° C., medium was removed and then replaced by 30 μl/well of DMEM medium containing 10% Nu serum, 400 μg/ml DEAE-dextran, 100 μM chloroquine, and 100 ng of the subject plasmids (i.e., 100 ng of the IC4A7 clone, and 100 ng of the MAGE-cDNA plasmid). Following four hours of incubation at 37° C., the medium was removed, and replaced by 50 μl of PBS containing 10% DMSO. This medium was removed after two minutes and replaced by 200 μl of DMEM supplemented with 10% FCS.
Following this change in medium, COS cells were incubated for 48 hours at 37° C. Medium was then discarded, and 2000 cells of CTL clone 81/12 were added, in 100 μl of Iscove medium containing 10% pooled human serum. Supernatant was removed after 24 hours, and TNF content was determined in an assay on WEHI cells, as described by Traversari et al., Immunogenetics 35: 145-152 (1992), the disclosure of which is incorporated by reference.
The results, set forth in FIG. 1 demonstrate that a tumor rejection antigen, derived from MAGE-1, is presented by HLA-C-clone 10, and is recognized by CTL clone 81/12, whereas expression of MAGE-2 and MAGE-3 does not lead to presentation of the appropriate antigen.
The foregoing experiments demonstrate that HLA-C-clone 10 presents a MAGE-1 derived peptide as a tumor rejection antigen, leading to lysis of the presenting cells. There are ramifications of this finding, discussed infra. For example, CTL clone 81/12 is representative of CTLs specific for the complex in question. Administration of such CTLs to a subject is expected to be therapeutically useful when the patient presents HLA-C-clone 10 phenotype on abnormal cells. It is within the skill of the artisan to develop the necessary CTLs in vitro. Specifically, a sample of cells, such as blood cells, are contacted to a cell presenting the complex and capable of provoking a specific CTL to proliferate. The target cell can be a transfectant, such as a COS cell of the type described supra. These transfectants present the desired complex on their surface and, when combined with a CTL of interest, stimulate its proliferation. It has been pointed out that the sequence for HLA-C is known to the art through GENBANK and EMBL, and the sequence for MAGE-1, together with a detailed protocol for its isolation, is provided by the PCT application and Van der Bruggen et al., both of which are incorporated by reference in their entirety, supra. COS cells, such as those used herein are widely available, as are other suitable host cells.
To detail the therapeutic methodology, referred to as adoptive transfer (Greenberg, J. Immunol. 136(5): 1917 (1986); Riddel et al., Science 257: 238 (Jul. 10, 1992); Lynch et al., Eur. J. Immunol. 21: 1403-1410 (1991); Kast et al., Cell 59: 603-614 (Nov. 17, 1989), cells presenting the desired complex are combined with CTLs leading to proliferation of the CTLs specific thereto. The proliferated CTLs are then administered to a subject with a cellular abnormality which is characterized by certain of the abnormal cells presenting the particular complex. The CTLs then lyse the abnormal cells, thereby achieving the desired therapeutic goal.
The foregoing therapy assumes that at least some of the subject's abnormal cells present the HLA-C-clone 10/MAGE-1 derived peptide complex. This can be determined very easily. For example CTLs are identified using the transfectants discussed supra, and once isolated, can be used with a sample of a subject's abnormal cells to determine lysis in vitro. If lysis is observed, then the use of specific CTLs in such a therapy may alleviate the condition associated with the abnormal cells. A less involved methodology examines the abnormal cells for HLA-C clone 10, and of MAGE-1 expression via amplification using, e.g., PCR.
Adoptive transfer is not the only form of therapy that is available in accordance with the invention. CTLs can also be provoked in vivo, using a number of approaches. One approach, i.e., the use of non-proliferative cells expressing the complex, has been elaborated upon supra. The cells used in this approach may be those that normally express the complex, such as irradiated melanoma cells or cells transfected with one or both of the genes necessary for presentation of the complex. Chen et al., Proc. Natl. Acad. Sci. U.S.A. 88: 110-114 (January, 1991) exemplify this approach, showing the use of transfected cells expressing HPVE7 peptides in a therapeutic regime. Various cell types may be used. Similarly, vectors carrying one or both of the genes of interest may be used. Viral or bacterial vectors are especially preferred. In these systems, the gene of interest is carried by, e.g., a Vaccinia virus or the bacteria BCG, and the materials de facto "infect" host cells. The cells which result present the complex of interest, and are recognized by autologous CTLs, which then proliferate. A similar effect can be achieved by combining MAGE-1 itself with an adjuvant to facilitate incorporation into HLA-C-clone 10 presenting cells. The protein is then processed to yield the peptide partner of the HLA molecule.
The foregoing discussion refers to "abnormal cells" and "cellular abnormalities". These terms are employed in their broadest interpretation, and refer to any situation where the cells in question exhibit at least one property which indicates that they differ from normal cells of their specific type. Examples of abnormal properties include morphological and biochemical changes, e.g. Cellular abnormalities include tumors, such as melanoma, autoimmune disorders, and so forth.
Other aspects of the invention will be clear to the skilled artisan and need not be repeated here.
The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, it being recognized that various modifications are possible within the scope of the invention.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 1(2) INFORMATION FOR SEQ ID NO: 1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 17 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 1:ACTCCATGAGGTATTTC17__________________________________________________________________________
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The invention relates to the identification of complexes of HLA-C-clone 10 and MAGE-1 derived peptides on the surfaces of abnormal cells. The therapeutic and diagnostic ramifications of this observation are the subject of the invention.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Patent Application No. 60/728,911 filed on Oct. 21 , 2005, and which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
The present invention relates to electrically variable transmissions having three planetary gear sets and three motor/generators that are controllable to provide continuously variable speed ratio ranges.
BACKGROUND OF THE INVENTION
Electric hybrid vehicles offer the potential for significant fuel economy improvements over their conventional counterparts; however, their overall efficiency is limited by parasitic losses. In single-mode electric variable transmissions (EVT) these losses are mostly attributed to electric machines rotating at high speeds. Two-mode EVTs offer the advantage of reduced motor-generator speeds, but often suffer losses attributed to high-pressure hydraulic pump and clutches needed for mode switching. Significant vehicle fuel economy gains can be realized if the losses associated with high-pressure hydraulic pump, clutches and high motor-generator speeds are substantially eliminated.
SUMMARY OF THE INVENTION
This invention describes continuously-variable mechatronic hybrid transmissions that offer the advantages of multi-mode EVTs without the need for clutches and the associated high pressure hydraulic pump.
The electrically variable transmission family of the present invention provides low-content, low-cost electrically variable transmission mechanisms including first, second and third differential gear sets, a battery (or similar energy storage device) and three electric machines serving interchangeably as motors or generators. Preferably, the differential gear sets are planetary gear sets, but other gear arrangements may be implemented, such as bevel gears or differential gearing to an offset axis.
In this description, the first, second and third planetary gear sets may be counted first to third in any order (i.e., left to right, right to left, etc.).
Each of the three planetary gear sets has three members. The first, second or third member of each planetary gear set can be any one of a sun gear, ring gear or carrier, or alternatively a pinion.
Each carrier can be either a single-pinion carrier (simple) or a double-pinion carrier (compound).
The input shaft is continuously connected with a member of the planetary gear sets. The output shaft is continuously connected with another member of the planetary gear sets.
A first interconnecting member continuously connects the first member of the first planetary gear set with the first member of the second planetary gear set and the first member of the third planetary gear set.
A second interconnecting member continuously connects the second member of the first planetary gear set with the second member of the second planetary gear set.
A first motor/generator is connected to a member of the first or second planetary gear set.
A second motor/generator is connected to a member of the second or third planetary gear set.
A third motor/generator is connected to a member of the first or third planetary gear set.
In essence, the planetary gear arrangement has six nodes, five of which are connected with the input shaft, output shaft and three motor/generators. The electric motor/generators are connected with drive units, control system and energy storage devices, such as a battery.
The three motor/generators are operated in a coordinated fashion to yield continuously variable forward and reverse speed ratios between the input shaft and the output shaft, while minimizing the rotational speeds of the motor-generators and optimizing the overall efficiency of the system. The tooth ratios of the planetary gear sets can be suitably selected to match specific applications.
The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
FIG. 2 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
FIG. 3 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
FIG. 4 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
FIG. 5 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
FIG. 6 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
FIG. 7 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
FIG. 8 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
FIG. 9 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention; and
FIG. 10 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1 , a powertrain 10 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 14 . Transmission 14 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 14 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 14 .
An output member 19 of the transmission 14 is connected to a final drive 16 .
The transmission 14 utilizes three differential gear sets, preferably in the nature of planetary gear sets 20 , 30 and 40 . The planetary gear set 20 employs an outer gear member 24 , typically designated as the ring gear. The ring gear member 24 circumscribes an inner gear member 22 , typically designated as the sun gear. A carrier member 26 rotatably supports a plurality of planet gears 27 such that each planet gear 27 simultaneously, and meshingly engages both the outer, ring gear member 24 and the inner, sun gear member 22 of the first planetary gear set 20 .
The planetary gear set 30 also employs an outer gear member 34 , typically designated as the ring gear. The ring gear member 34 circumscribes an inner gear member 32 , typically designated as the sun gear. A carrier member 36 rotatably supports a plurality of planet gears 37 such that each planet gear 37 simultaneously, and meshingly engages both the outer, ring gear member 34 and the inner, sun gear member 32 of the planetary gear set 30 .
The planetary gear set 40 also employs an outer gear member 44 , typically designated as the ring gear. The ring gear member 44 circumscribes an inner gear member 42 , typically designated as the sun gear. A carrier member 46 rotatably supports a plurality of planet gears 47 such that each planet gear 47 simultaneously, and meshingly engages both the outer, ring gear member 44 and the inner, sun gear member 42 of the planetary gear set 40 .
The input shaft 17 is continuously connected to the carrier member 46 of the planetary gear set 40 . The output shaft 19 is continuously connected to the carrier member 26 of the planetary gear set 20 .
A first interconnecting member 70 continuously connects the sun gear member 22 of the planetary gear set 20 with the sun gear member 32 of the planetary gear set 30 and with the ring gear member 44 of the planetary gear set 40 . A second interconnecting member 72 continuously connects the ring gear member 24 of the planetary gear set 20 with the carrier member 36 of the planetary gear set 30 .
The first preferred embodiment 10 also incorporates first, second and third motor/generators 80 , 82 and 84 , respectively. The stator of the first motor/generator 80 is secured to the transmission housing 60 . The rotor of the first motor/generator 80 is secured to the ring gear member 24 of the planetary gear set 20 .
The stator of the second motor/generator 82 is secured to the transmission housing 60 . The rotor of the second motor/generator 82 is secured to the ring gear member 34 of the planetary gear set 30 .
The stator of the third motor/generator 84 is secured to the transmission housing 60 . The rotor of the third motor/generator 84 is secured to the sun gear member 42 of the planetary gear set 40 .
Returning now to the description of the power sources, it should be apparent from the foregoing description, and with particular reference to FIG. 1 , that the transmission 14 selectively receives power from the engine 12 . The hybrid transmission also receives power from an electric power source 86 , which is operably connected to a controller 88 . The electric power source 86 may be one or more batteries. Other electric power sources, such as capacitors or fuel cells, that have the ability to provide, or store, and dispense electric power may be used in place of or in combination with batteries without altering the concepts of the present invention. The speed ratio between the input shaft and output shaft is prescribed by the speeds of the three motor/generators and the ring gear/sun gear tooth ratios of the planetary gear sets. Those with ordinary skill in the transmission art will recognize that desired input/output speed ratios can be realized by suitable selection of the speeds of the three motor/generators.
Description of a Second Exemplary Embodiment
With reference to FIG. 2 , a powertrain 110 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 114 . Transmission 114 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 114 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 114 .
An output member 19 of the transmission 114 is connected to a final drive 16 .
The transmission 114 utilizes three differential gear sets, preferably in the nature of planetary gear sets 120 , 130 and 140 . The planetary gear set 120 employs an outer gear member 124 , typically designated as the ring gear. The ring gear member 124 circumscribes an inner gear member 122 , typically designated as the sun gear. A carrier member 126 rotatably supports a plurality of planet gears 127 such that each planet gear 127 simultaneously, and meshingly engages both the outer, ring gear member 124 and the inner, sun gear member 122 of the first planetary gear set 120 .
The planetary gear set 130 also employs an outer gear member 134 , typically designated as the ring gear. The ring gear member 134 circumscribes an inner gear member 132 , typically designated as the sun gear. A carrier member 136 rotatably supports a plurality of planet gears 137 such that each planet gear 137 simultaneously, and meshingly engages both the outer, ring gear member 134 and the inner, sun gear member 132 of the planetary gear set 130 .
The planetary gear set 140 also employs an outer gear member 144 , typically designated as the ring gear. The ring gear member 144 circumscribes an inner gear member 142 , typically designated as the sun gear. A carrier member 146 rotatably supports a plurality of planet gears 147 such that each planet gear 147 simultaneously, and meshingly engages both the outer, ring gear member 144 and the inner, sun gear member 142 of the planetary gear set 140 .
The input shaft 17 is continuously connected to the sun gear member 142 of the planetary gear set 140 . The output shaft 19 is continuously connected to the ring gear member 124 of the planetary gear set 120 .
A first interconnecting member 170 continuously connects the sun gear member 122 of the planetary gear set 120 with the carrier member 136 of the planetary gear set 130 and with the carrier member 146 of the planetary gear set 140 . A second interconnecting member 172 continuously connects the carrier member 126 of the planetary gear set 120 with the ring gear member 134 of the planetary gear set 130 .
The second preferred embodiment 110 also incorporates first, second and third motor/generators 180 , 182 and 184 , respectively. The stator of the first motor/generator 180 is secured to the transmission housing 160 . The rotor of the first motor/generator 180 is secured to the carrier member 126 of the planetary gear set 120 .
The stator of the second motor/generator 182 is secured to the transmission housing 160 . The rotor of the second motor/generator 182 is secured to the sun gear member 132 of the planetary gear set 130 .
The stator of the third motor/generator 184 is secured to the transmission housing 160 . The rotor of the third motor/generator 184 is secured to the ring gear member 144 of the planetary gear set 140 .
The hybrid transmission 114 receives power from the engine 12 , and also exchanges power with an electric power source 186 , which is operably connected to a controller 188 .
Description of a Third Exemplary Embodiment
With reference to FIG. 3 , a powertrain 210 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 214 . Transmission 214 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 214 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 214 .
An output member 19 of the transmission 214 is connected to a final drive 16 .
The transmission 214 utilizes three differential gear sets, preferably in the nature of planetary gear sets 220 , 230 and 240 . The planetary gear set 220 employs an outer gear member 224 , typically designated as the ring gear. The ring gear member 224 circumscribes an inner gear member 222 , typically designated as the sun gear. A carrier member 226 rotatably supports a plurality of planet gears 227 such that each planet gear 227 simultaneously, and meshingly engages both the outer, ring gear member 224 and the inner, sun gear member 222 of the first planetary gear set 220 .
The planetary gear set 230 also employs an outer gear member 234 , typically designated as the ring gear. The ring gear member 234 circumscribes an inner gear member 232 , typically designated as the sun gear. A carrier member 236 rotatably supports a plurality of planet gears 237 such that each planet gear 237 simultaneously, and meshingly engages both the outer, ring gear member 234 and the inner, sun gear member 232 of the planetary gear set 230 .
The planetary gear set 240 also employs an outer gear member 244 , typically designated as the ring gear. The ring gear member 244 circumscribes an inner gear member 242 , typically designated as the sun gear. A carrier member 246 rotatably supports a plurality of planet gears 247 such that each planet gear 247 simultaneously, and meshingly engages both the outer, ring gear member 244 and the inner, sun gear member 242 of the planetary gear set 240 .
The input shaft 17 is continuously connected to the carrier member 246 of the planetary gear set 240 . The output shaft 19 is continuously connected to the carrier member 226 of the planetary gear set 220 .
A first interconnecting member 270 continuously connects the ring gear member 224 with the carrier member 236 and with the ring gear member 244 . A second interconnecting member 272 continuously connects the sun gear member 222 with the sun gear member 232 .
The preferred embodiment 210 also incorporates first, second and third motor/generators 280 , 282 and 284 , respectively. The stator of the first motor/generator 280 is secured to the transmission housing 260 . The rotor of the first motor/generator 280 is secured to the carrier member 226 of the planetary gear set 240 , and therefore the output member 19 .
The stator of the second motor/generator 282 is secured to the transmission housing 260 . The rotor of the second motor/generator 282 is secured to the ring gear member 234 of the planetary gear set 230 .
The stator of the third motor/generator 284 is secured to the transmission housing 260 . The rotor of the third motor/generator 284 is secured to the sun gear member 242 of the planetary gear set 240 .
The hybrid transmission 214 receives power from the engine 12 , and also exchanges power with an electric power source 286 , which is operably connected to a controller 288 .
Description of a Fourth Exemplary Embodiment
With reference to FIG. 4 , a powertrain 310 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 314 . Transmission 314 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 314 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 14 . An output member 19 of the transmission 314 is connected to a final drive 16 .
The transmission 314 utilizes three differential gear sets, preferably in the nature of planetary gear sets 320 , 330 and 340 . The planetary gear set 320 employs an outer gear member 324 , typically designated as the ring gear. The ring gear member 324 circumscribes an inner gear member 322 , typically designated as the sun gear. A carrier member 326 rotatably supports a plurality of planet gears 327 such that each planet gear 327 simultaneously, and meshingly engages both the outer, ring gear member 324 and the inner, sun gear member 322 of the first planetary gear set 320 .
The planetary gear set 330 also employs an outer gear member 334 , typically designated as the ring gear. The ring gear member 334 circumscribes an inner gear member 332 , typically designated as the sun gear. A carrier member 336 rotatably supports a plurality of planet gears 337 such that each planet gear 337 simultaneously, and meshingly engages both the outer, ring gear member 334 and the inner, sun gear member 332 of the planetary gear set 330 .
The planetary gear set 340 also employs an outer gear member 344 , typically designated as the ring gear. The ring gear member 344 circumscribes an inner gear member 342 , typically designated as the sun gear. A carrier member 346 rotatably supports a plurality of planet gears 347 such that each planet gear 347 simultaneously, and meshingly engages both the outer, ring gear member 344 and the inner, sun gear member 342 of the planetary gear set 340 .
The input shaft 17 is continuously connected to the carrier member 326 of the planetary gear set 320 . The output shaft 19 is continuously connected to the carrier member 346 of the planetary gear set 340 .
A first interconnecting member 370 continuously connects the carrier member 326 with the sun gear member 332 and with the ring gear member 344 . A second interconnecting member 372 continuously connects the sun gear member 322 with the ring gear member 334 .
The preferred embodiment 310 also incorporates first, second and third motor/generators 380 , 382 and 384 , respectively. The stator of the first motor/generator 380 is secured to the transmission housing 360 . The rotor of the first motor/generator 380 is secured to the ring gear member 324 .
The stator of the second motor/generator 382 is secured to the transmission housing 360 . The rotor of the second motor/generator 382 is secured to the carrier member 336 .
The stator of the third motor/generator 384 is secured to the transmission housing 360 . The rotor of the third motor/generator 384 is secured to the sun gear member 342 .
The hybrid transmission 314 receives power from the engine 12 , and also exchanges power with an electric power source 386 , which is operably connected to a controller 388 .
Description of a Fifth Exemplary Embodiment
With reference to FIG. 5 , a powertrain 410 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 414 . Transmission 414 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 414 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 414 . An output member 19 of the transmission 414 is connected to a final drive 16 .
The transmission 414 utilizes three differential gear sets, preferably in the nature of planetary gear sets 420 , 430 and 440 . The planetary gear set 420 employs an outer gear member 424 , typically designated as the ring gear. The ring gear member 424 circumscribes an inner gear member 422 , typically designated as the sun gear. A carrier member 426 rotatably supports a plurality of planet gears 427 such that each planet gear 427 simultaneously, and meshingly engages both the outer, ring gear member 424 and the inner, sun gear member 422 of the first planetary gear set 420 .
The planetary gear set 430 also employs an outer gear member 434 , typically designated as the ring gear. The ring gear member 434 circumscribes an inner gear member 432 , typically designated as the sun gear. A carrier member 436 rotatably supports a plurality of planet gears 437 such that each planet gear 437 simultaneously, and meshingly engages both the outer, ring gear member 434 and the inner, sun gear member 432 of the planetary gear set 430 .
The planetary gear set 440 also employs an outer gear member 444 , typically designated as the ring gear. The ring gear member 444 circumscribes an inner gear member 442 , typically designated as the sun gear. A carrier member 446 rotatably supports a plurality of planet gears 447 such that each planet gear 447 simultaneously, and meshingly engages both the outer, ring gear member 444 and the inner, sun gear member 442 of the planetary gear set 440 .
The input shaft 17 is continuously connected to the sun gear member 422 . The output shaft 19 is continuously connected to the ring gear member 444 .
A first interconnecting member 470 continuously connects the ring gear member 424 with the sun gear member 432 and with the sun gear member 442 . A second interconnecting member 472 continuously connects the carrier member 426 with the ring gear member 434 .
The preferred embodiment 410 also incorporates first, second and third motor/generators 480 , 482 and 484 , respectively. The stator of the first motor/generator 480 is secured to the transmission housing 460 . The rotor of the first motor/generator 480 is secured to the carrier member 436 .
The stator of the second motor/generator 482 is secured to the transmission housing 460 . The rotor of the second motor/generator 482 is secured to the sun gear member 432 .
The stator of the third motor/generator 484 is secured to the transmission housing 460 . The rotor of the third motor/generator 484 is secured to the carrier member 446 .
The hybrid transmission 414 receives power from the engine 12 , and also exchanges power with an electric power source 486 , which is operably connected to a controller 488 .
Description of a Sixth Exemplary Embodiment
With reference to FIG. 6 , a powertrain 510 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 514 . Transmission 514 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 514 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 514 . An output member 19 of the transmission 514 is connected to a final drive 16 .
The transmission 514 utilizes three differential gear sets, preferably in the nature of planetary gear sets 520 , 530 and 540 . The planetary gear set 520 employs an outer gear member 524 , typically designated as the ring gear. The ring gear member 524 circumscribes an inner gear member 522 , typically designated as the sun gear. A carrier member 526 rotatably supports a plurality of planet gears 527 such that each planet gear 527 simultaneously, and meshingly engages both the outer, ring gear member 524 and the inner, sun gear member 522 of the planetary gear set 520 .
The planetary gear set 530 also employs an outer gear member 534 , typically designated as the ring gear. The ring gear member 534 circumscribes an inner gear member 532 , typically designated as the sun gear. A carrier member 536 rotatably supports a plurality of planet gears 537 such that each planet gear 537 simultaneously, and meshingly engages both the outer, ring gear member 534 and the inner, sun gear member 532 of the planetary gear set 530 .
The planetary gear set 540 also employs an outer gear member 544 , typically designated as the ring gear. The ring gear member 544 circumscribes an inner gear member 542 , typically designated as the sun gear. A carrier member 546 rotatably supports a plurality of planet gears 547 such that each planet gear 547 simultaneously, and meshingly engages both the outer, ring gear member 544 and the inner, sun gear member 542 of the planetary gear set 540 .
The input shaft 17 is continuously connected to the sun gear member 532 . The output shaft 19 is continuously connected to the ring gear member 544 .
A first interconnecting member 570 continuously connects the carrier member 526 with the ring gear member 534 and with the sun gear member 542 . A second interconnecting member 572 continuously connects the ring gear member 524 with the carrier member 536 .
The preferred embodiment 510 also incorporates first, second and third motor/generators 580 , 582 and 584 , respectively. The stator of the first motor/generator 580 is secured to the transmission housing 560 . The rotor of the first motor/generator 580 is secured to the sun gear member 522 .
The stator of the second motor/generator 582 is secured to the transmission housing 560 . The rotor of the second motor/generator 582 is secured to the carrier member 526 .
The stator of the third motor/generator 584 is secured to the transmission housing 560 . The rotor of the third motor/generator 584 is secured to the carrier member 546 .
The hybrid transmission 514 receives power from the engine 12 , and also exchanges power with an electric power source 586 , which is operably connected to a controller 588 .
Description of a Seventh Exemplary Embodiment
With reference to FIG. 7 , a powertrain 610 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 614 . Transmission 614 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 614 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 614 . An output member 19 of the transmission 614 is connected to a final drive 16 .
The transmission 614 utilizes three differential gear sets, preferably in the nature of planetary gear sets 620 , 630 and 640 . The planetary gear set 620 employs an outer gear member 624 , typically designated as the ring gear. The ring gear member 624 circumscribes an inner gear member 622 , typically designated as the sun gear. A carrier member 626 rotatably supports a plurality of planet gears 627 such that each planet gear 627 simultaneously, and meshingly engages both the outer, ring gear member 624 and the inner, sun gear member 622 of the first planetary gear set 620 .
The planetary gear set 630 also employs an outer gear member 634 , typically designated as the ring gear. The ring gear member 634 circumscribes an inner gear member 632 , typically designated as the sun gear. A carrier member 636 rotatably supports a plurality of planet gears 637 such that each planet gear 637 simultaneously, and meshingly engages both the outer, ring gear member 634 and the inner, sun gear member 632 of the planetary gear set 630 .
The planetary gear set 640 also employs an outer gear member 644 , typically designated as the ring gear. The ring gear member 644 circumscribes an inner gear member 642 , typically designated as the sun gear. A carrier member 646 rotatably supports a plurality of planet gears 647 such that each planet gear 647 simultaneously, and meshingly engages both the outer, ring gear member 644 and the inner, sun gear member 642 of the planetary gear set 640 .
The input shaft 17 is continuously connected to the sun gear member 622 . The output shaft 19 is continuously connected to the ring gear member 644 .
A first interconnecting member 670 continuously connects the carrier member 626 with the carrier member 636 and with the sun gear member 642 . A second interconnecting member 672 continuously connects the ring gear member 624 with the sun gear member 632 .
The preferred embodiment 610 also incorporates first, second and third motor/generators 680 , 682 and 684 , respectively. The stator of the first motor/generator 680 is secured to the transmission housing 660 . The rotor of the first motor/generator 680 is secured to the ring gear member 624 .
The stator of the second motor/generator 682 is secured to the transmission housing 660 . The rotor of the second motor/generator 682 is secured to the ring gear member 634 .
The stator of the third motor/generator 684 is secured to the transmission housing 660 . The rotor of the third motor/generator 684 is secured to the carrier member 646 .
The hybrid transmission 614 receives power from the engine 12 , and also exchanges power with an electric power source 686 , which is operably connected to a controller 688 .
Description of an Eighth Exemplary Embodiment
With reference to FIG. 8 , a powertrain 710 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 714 . Transmission 714 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 714 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 714 . An output member 19 of the transmission 714 is connected to a final drive 16 .
The transmission 714 utilizes three differential gear sets, preferably in the nature of planetary gear sets 720 , 730 and 740 . The planetary gear set 720 employs an outer gear member 724 , typically designated as the ring gear. The ring gear member 724 circumscribes an inner gear member 722 , typically designated as the sun gear. A carrier member 726 rotatably supports a plurality of planet gears 727 , 728 . Each planet gear 727 meshingly engages the sun gear member 722 , and each planet gear 728 simultaneously, and meshingly engages both the ring gear member 724 and the respective planet gear 727 .
The planetary gear set 730 also employs an outer gear member 734 , typically designated as the ring gear. The ring gear member 734 circumscribes an inner gear member 732 , typically designated as the sun gear. A carrier member 736 rotatably supports a plurality of planet gears 737 such that each planet gear 737 simultaneously, and meshingly engages both the outer, ring gear member 734 and the inner, sun gear member 732 of the planetary gear set 730 .
The planetary gear set 740 also employs an outer gear member 744 , typically designated as the ring gear. The ring gear member 744 circumscribes an inner gear member 742 , typically designated as the sun gear. A carrier member 746 rotatably supports a plurality of planet gears 747 such that each planet gear 747 simultaneously, and meshingly engages both the outer, ring gear member 744 and the inner, sun gear member 742 of the planetary gear set 740 .
The input shaft 17 is continuously connected to the carrier member 726 . The output shaft 19 is continuously connected to the carrier member 746 .
A first interconnecting member 770 continuously connects the sun gear member 722 with the sun gear member 732 and with the ring gear member 744 . A second interconnecting member 772 continuously connects the carrier member 726 with the carrier member 736 .
The preferred embodiment 710 also incorporates first, second and third motor/generators 780 , 782 and 784 , respectively. The stator of the first motor/generator 780 is secured to the transmission housing 760 . The rotor of the first motor/generator 780 is secured to the ring gear member 724 .
The stator of the second motor/generator 782 is secured to the transmission housing 760 . The rotor of the second motor/generator 782 is secured to the ring gear member 734 .
The stator of the third motor/generator 784 is secured to the transmission housing 760 . The rotor of the third motor/generator 784 is secured to the sun gear member 742 .
The hybrid transmission 714 receives power from the engine 12 , and also exchanges power with an electric power source 786 , which is operably connected to a controller 788 .
Description of a Ninth Exemplary Embodiment
With reference to FIG. 9 , a powertrain 810 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 814 . Transmission 814 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 814 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 814 . An output member 19 of the transmission 814 is connected to a final drive 16 .
The transmission 814 utilizes three differential gear sets, preferably in the nature of planetary gear sets 820 , 830 and 840 . The planetary gear set 820 employs an outer gear member 824 , typically designated as the ring gear. The ring gear member 824 circumscribes an inner gear member 822 , typically designated as the sun gear. A carrier member 826 rotatably supports a plurality of planet gears 827 such that each planet gear 827 simultaneously, and meshingly engages both the outer, ring gear member 824 and the inner, sun gear member 822 of the planetary gear set 820 .
The planetary gear set 830 also employs an outer gear member 834 , typically designated as the ring gear. The ring gear member 834 circumscribes an inner gear member 832 , typically designated as the sun gear. A carrier member 836 rotatably supports a plurality of planet gears 837 such that each planet gear 837 simultaneously, and meshingly engages both the outer, ring gear member 834 and the inner, sun gear member 832 of the planetary gear set 830 .
The planetary gear set 840 also employs an outer gear member 844 , typically designated as the ring gear. The ring gear member 844 circumscribes an inner gear member 842 , typically designated as the sun gear. A carrier member 846 rotatably supports a plurality of planet gears 847 such that each planet gear 847 simultaneously, and meshingly engages both the outer, ring gear member 844 and the inner, sun gear member 842 of the planetary gear set 840 .
The input shaft 17 is continuously connected to the sun gear member 842 . The output shaft 19 is continuously connected to the ring gear member 824 .
A first interconnecting member 870 continuously connects the sun gear member 822 with the ring gear member 834 and with the carrier member 846 . A second interconnecting member 872 continuously connects the carrier member 826 with the carrier member 836 .
The preferred embodiment 810 also incorporates first, second and third motor/generators 880 , 882 and 884 , respectively. The stator of the first motor/generator 880 is secured to the transmission housing 860 . The rotor of the first motor/generator 880 is secured to the sun gear member 832 .
The stator of the second motor/generator 882 is secured to the transmission housing 860 . The rotor of the second motor/generator 882 is secured to the carrier member 836 .
The stator of the third motor/generator 884 is secured to the transmission housing 860 . The rotor of the third motor/generator 884 is secured to the ring gear member 844 .
The hybrid transmission 814 receives power from the engine 12 , and also exchanges power with an electric power source 886 , which is operably connected to a controller 888 .
Description of a Tenth Exemplary Embodiment
With reference to FIG. 10 , a powertrain 910 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 914 . Transmission 914 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 914 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 914 . An output member 19 of the transmission 914 is connected to a final drive 16 .
The transmission 914 utilizes three differential gear sets, preferably in the nature of planetary gear sets 920 , 930 and 940 . The planetary gear set 920 employs an outer gear member 924 , typically designated as the ring gear. The ring gear member 924 circumscribes an inner gear member 922 , typically designated as the sun gear. A carrier member 926 rotatably supports a plurality of planet gears 927 such that each planet gear 927 simultaneously, and meshingly engages both the outer, ring gear member 924 and the inner, sun gear member 922 of the planetary gear set 920 .
The planetary gear set 930 employs an outer gear member 934 , typically designated as the ring gear. The ring gear member 934 circumscribes an inner gear member 932 , typically designated as the sun gear. A carrier member 936 rotatably supports a plurality of planet gears 937 such that each planet gear 937 simultaneously, and meshingly engages both the outer, ring gear member 934 and the inner, sun gear member 932 of the planetary gear set 930 .
The planetary gear set 940 employs an outer gear member 944 , typically designated as the ring gear. The ring gear member 944 circumscribes an inner gear member 942 , typically designated as the sun gear. A carrier member 946 rotatably supports a plurality of planet gears 947 such that each planet gear 947 simultaneously, and meshingly engages both the outer, ring gear member 944 and the inner, sun gear member 942 of the planetary gear set 940 .
The input shaft 17 is continuously connected to the carrier member 926 . The output shaft 19 is continuously connected to the carrier member 946 .
A first interconnecting member 970 continuously connects the sun gear member 922 with the ring gear member 934 and with the sun gear member 942 . A second interconnecting member 972 continuously connects the ring gear member 924 with the carrier member 936 .
The preferred embodiment 910 also incorporates first, second and third motor/generators 980 , 982 and 984 , respectively. The stator of the first motor/generator 980 is secured to the transmission housing 960 . The rotor of the first motor/generator 980 is secured to the ring gear member 924 via an offset drive 990 , such as a belt or chain, which may change the speed ratio.
The stator of the second motor/generator 982 is secured to the transmission housing 960 . The rotor of the second motor/generator 982 is secured to the sun gear member 932 .
The stator of the third motor/generator 984 is secured to the transmission housing 960 . The rotor of the third motor/generator 984 is secured to the ring gear member 944 via offset gear 992 .
The hybrid transmission 914 receives power from the engine 12 , and also exchanges power with an electric power source 986 , which is operably connected to a controller 988 .
While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.
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The electrically variable transmission family of the present invention provides low-content, low-cost electrically variable transmission mechanisms including first, second and third differential gear sets, a battery and three electric machines serving interchangeably as motors or generators. The three motor/generators are operable in a coordinated fashion to yield an EVT with a continuously variable range of speeds (including reverse).
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a National Phase Application of International Application No. PCT/EP2007/053933, filed on Apr. 23, 2007, which claims the benefit of and priority to German patent application no. DE 10 2006 020 000.4-14, filed Apr. 26, 2006. The disclosure of the above applications are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a method for producing low-springback half shells made of a metal, in particular steel or a steel alloy, in which blanks are drawn in at least one drawing die, such that the blanks have flange regions on the deep drawn body after the deep drawing and also to a device for producing low-springback half shells. In addition, the invention relates to a method for producing closed hollow profiles, in particular modular tubes, in which method at least two half shells are positioned in such a way that the edges each form a butt joint and the half shells are welded to one another along the edges, in particular using a laser beam, and also to a closed hollow profile which is produced from the half shells according to the invention and is made of a metal, in particular of steel or a steel alloy.
BACKGROUND
[0003] In motor vehicles, use is increasingly being made of closed hollow profiles having cross sections and material thicknesses adapted specifically to the case of application. In the past, closed hollow profiles have generally been produced first by shaping a tube, subjecting the tube to appropriate bending or pre-deformation and subsequently carrying out hydroforming of the pre-bent or pre-deformed shape to form the final shape of the closed hollow profile. On the one hand, not all components can be produced in this way, as during the hydroforming local extensions of the material are exceeded, so that cracks can form. In addition, uncontrollable wrinkling can occur during the hydroforming. On the other hand, the previously used method steps for producing a closed hollow profile which is adapted to the application in question are very complex and thus cost-intensive. Although a closed hollow profile can in principle also be produced from two deep drawn half shells, stresses are introduced into the blank during deep drawing of a blank and can lead to springback of the blank. However, the springback of the half shells hinders precise positioning of the half shells in a die for welding. In the past, welding of the edges of the half shells in a butt joint was not possible without great expense owing to the springback of the half shells. For this reason, closed hollow profiles consisting of welded half shells have in the past conventionally been welded to the protruding flange regions. However, the protruding weld seam prevents these closed hollow profiles from being inserted like closed hollow profiles which are produced from a welded tube and have no protruding weld seam. Also, the flanges significantly increase the total weight of the component.
[0004] A method for producing half shells is known from published Japanese patent application JP 08/168830, in which method a blank is first deep drawn in a die, such that protruding flange regions are produced. The flange regions are subsequently upset and sheared off at the same time via an upper cutting and upsetting swage. However, owing to the geometry of the upper cutting/upsetting swage, the half shells thus obtained display non-uniformities at the edges of the half shells, so that said half shells are not suitable for welding in a butt joint. In addition, the known cutting/upsetting does not lead to sufficiently low-stress half shells which are suitable for being welded to one another in a butt joint.
SUMMARY OF THE INVENTION
[0005] In one aspect, the present invention provides a method and a device for producing low-springback half shells made of metal, in particular steel or a steel alloy, allowing the production of low-springback half shells having edge regions suitable for welding in the butt joint. In another aspect, the present invention provides closed hollow profiles produced from half shells according to the invention and also a corresponding production method for closed hollow profiles.
[0006] According to a first teaching of the present invention, a method for producing low-springback half shells made of a metal includes shaping the flange regions by upsetting a corner substantially perpendicularly to the wall of the body of the deep drawn blank and subsequently trimming the flange regions in a shearing die, such that half shells without margins are produced.
[0007] As a result of the upsetting according to the invention of a corner into the flange regions, so that said flange regions are formed substantially perpendicularly to the wall of the body of the deep drawn blank, on the one hand the stresses introduced into the blank during the deep drawing are first partly equalized. The resulting half shell has low springback laterally to the body wall. On the other hand, after trimming of the flange regions, the surface of the edges of the half shells has a shape which is precisely defined during the upsetting and is predetermined by the upsetting tool for shaping the corners of the flange regions. This results from the fact that the cutting plane can run perpendicularly to the edge surface during the subsequent shearing-off. The resulting half shells therefore not only have low springback but rather also have the precisely defined geometrical edge shape in the axial direction that is desirable for welding in the butt joint. Conventionally, the edges of the half shells are shaped in a planar manner as a plateau to achieve good weldability in the butt joint. It is however also conceivable additionally to impress any other desired cross-sectional profile onto the edges of the half shells during the upsetting.
[0008] The springback properties of the half shells are further improved as a result of the fact that during and/or after the trimming of the flange regions, the body and/or the edges of the trimmed half shells are additionally upset. This additional upsetting further reduces any prevailing springback forces.
[0009] If, according to a subsequent further embodiment of the method according to the invention, the deep drawing of the blank and the shaping of the flange regions takes place in a single operation in the drawing die, the flange regions being shaped by a blank holder, the number of operations can be reduced to a minimum. For example, in this case, a single blank holder and a single upper deep drawing swage can facilitate deep drawing and corresponding shaping of the flange regions perpendicularly to the wall of the deep drawn region of the blank. It is however also conceivable to carry out the shaping of the flange regions by a further upper drawing swage, thus allowing the individual elements of the drawing die, for example the blank holder, to be configured in a simpler manner.
[0010] Preferably, an upsetting component is taken into account in the deep drawing of the blank in the drawing die, so that the actual depth of the body after the deep drawing is greater than required. The upsetting component provided is used to return by upsetting the stresses introduced into the regions during the deep drawing while nevertheless customizing the deep drawn body.
[0011] For the same reason, according to another embodiment of the method according to the invention, a reverse curve is introduced into the flange regions prior to the trimming. In particular, this additionally counteracts a springback moment which is introduced into the wall of the body and the flange regions during the deep drawing.
[0012] Preferably, the flange regions are trimmed by punching or alternatively using a laser beam. A punching press leads to reduced equipment costs. The use of a laser beam, on the other hand, prevents additional stresses and thus springback moments from being introduced into the half shells as a result of the trimming of the flange regions.
[0013] According to a second teaching of the present invention, a method for producing closed hollow profiles includes use of at least two half shells produced in accordance with the invention.
[0014] A greater degree of freedom for changes in cross section is obtained during the deep drawing of the half shells than during the conventionally used hydroforming. The different cross-sectional geometries are determined by a correspondingly configured drawing die. In this respect, the aforementioned method is particularly advantageous for producing modular tubes having variable cross-sectional shapes in the longitudinal direction. Owing to the paucity of springback, in particular laterally to the body wall, of the half shells produced in accordance with the invention, said half shells can readily be positioned in such a way that the edges each form an exact butt joint, as the half shells display very high dimensional precision owing to the paucity of springback. Preferably, a laser beam is used for welding the edges. Nevertheless, it is also conceivable to use conventional welding methods.
[0015] With regard to economical production of closed hollow profiles, the method according to the invention can be further improved as a result of the fact that at least two shearing dies are used to produce the half shells, the half shells are subsequently inserted into two contour dies and the two half shells are positioned relative to each other by a form fit of the two contour dies with each other using a suitable device. With the aid of two simple contour dies configured merely for receiving the half shells in a precisely defined position, the low-springback half shells can easily be positioned relative to each other with such precision that said half shells form a readily weldable butt joint. The form fit of the two contour dies with each other allows the positioning to be carried out in a reproducible manner, thus allowing procedural safety to be increased during the welding. Nevertheless, in addition to a form fit, other methods can alternatively also be used for precisely positioning the dies receiving the half shells. In addition, the contour dies can be replaced by even simpler positioning means, for example positioning pins, provided that the half shells can be produced almost without springback laterally to the body wall.
[0016] According to a further embodiment of the method according to the invention for producing closed hollow profiles, prior to the welding of the half shells there is inserted between the positioned half shells a resilient hose which is subjected to pressure via a pressure medium and remains between the half shells during the welding. Any remaining springback forces are counteracted by the use of the resilient hose, thus allowing, for example in conjunction with the contour dies which are used and in which the half shells are positioned for welding, the positional precision of the edges relative to one another again to be improved. Both liquid and gaseous media are suitable as pressure media in the hose.
[0017] Preferably, the resilient hose is thermally protected, in particular in the region of the weld seams. For example, a ceramic tape arranged in the region of the weld seams can protect the resilient hose from the temperature effect of the welding beams. It is however also conceivable to design the resilient hose directly with corresponding thermal protection.
[0018] According to a third teaching of the present invention, a closed hollow profile made of a metal, in particular of steel or a steel alloy, includes at least two low-springback half shells produced using the method according to the invention, the edges of which are welded to one another in the longitudinal direction via a butt joint. The closed hollow profiles can not only be produced particularly economically but also display high flexibility with regard to their shaping, thus allowing them to be used for example in the field of vehicle construction. In addition, they display much lower stresses than the closed hollow profiles previously produced from deep drawn half shells and having flanges, as low-springback half shells are used for production.
[0019] As stated hereinbefore, the half shells produced using the method according to the invention can be produced particularly easily via appropriate upper swage geometries of the drawing die, so that the closed hollow profile is preferably a modular tube.
[0020] Finally, according to a fourth teaching of the present invention, a device for producing half shells of a closed hollow profile includes a drawing die and a shearing die, the drawing die having at least a first upper swage and a first blank holder for drawing the blank and also for producing a flange region. The device also includes at least one further upper swage and (in some embodiments) a further blank holder. The further upper swage and further blank holder are provided for upsetting a corner in and for shaping the flange regions of the blank substantially perpendicularly to the wall of the body of the deep drawn blank.
[0021] As described hereinbefore, the device according to the invention can be used to produce half shells which on the one hand have low springback and have a precisely defined surface at the axial edges of the half shells. The device according to the invention is therefore suitable for producing, in a simple manner, flangeless half shells for producing closed hollow profiles.
[0022] If a first blank holder of the drawing die is provided, with which a corner can be upset into the flange regions of the blank and the flange regions can be shaped substantially perpendicularly to the wall of the body of the deep drawn blank, it is possible to produce half shells according to the invention in a two-stage process using the device according to the invention, as no additional upper swage has to be used for upsetting and shaping the flange regions.
[0023] If the shearing die of the device has an upper shearing swage for shearing off the flange regions which are shaped and an upper upsetting swage for upsetting the body and/or the edges of the half shell, a particularly simple upper shearing swage and a particularly simple upper upsetting swage can be used for carrying out the shearing and upsetting operations.
[0024] If the upper shearing swage of the shearing die is at the same time configured as an upper upsetting swage for the body and/or the edges of the half shell, it is for example possible to introduce into the flange region during the shearing-off reverse curves which make the shearing-off and the upsetting of the edge procedurally safer during the trimming of the half shell. In addition, the reverse curve reduces springback moments in the body that were caused by the deep drawing process.
[0025] A device according to the invention allows the cost-effectiveness with regard to the production of closed hollow profiles to be further improved as a result of the fact that two drawing dies, two shearing dies and two contour dies are provided. A corresponding device allows the blanks to be drawn, sheared off accordingly and welded to one another at the same time.
DESCRIPTION OF THE DRAWINGS
[0026] There are therefore a large number of possibilities for developing and configuring the method and device according to the invention for producing half shells made of metal and also the method according to the invention for producing closed hollow profiles, as well as the closed hollow profiles themselves. In this regard, reference is made on the one hand to the claims and on the other hand to the description of four exemplary embodiments in conjunction with the drawings, in which:
[0027] FIG. 1 is a schematic sectional view of the drawing and the shearing dies, respectively, during the carrying-out of an exemplary embodiment of the method according to the invention for producing low-springback half shells;
[0028] FIG. 2 is a schematic sectional view of an alternative shearing die during the carrying-out of the exemplary embodiment from FIG. 1 ;
[0029] FIG. 3 is a schematic sectional view of the drawing and shearing dies during the carrying-out of a third exemplary embodiment of the method according to the invention for producing low-springback half shells; and
[0030] FIG. 4 is an axial sectional view and also a plan view of a fourth exemplary embodiment of a closed hollow profile according to the invention.
DESCRIPTION
[0031] FIG. 1 a ) to 1 h ) are schematic radial sectional views of one half of a drawing die 1 and a shearing die 2 at different points in time during the carrying-out of an exemplary embodiment of the method according to the invention. The drawing die 1 comprises a bottom swage 3 , a blank holder 4 and an upper swage 5 for drawing the blank 6 . The blank 6 is first inserted into the drawing die 1 and fixed via the blank holder 4 and spacers 7 , 8 , as FIG. 1 a ) shows. FIG. 1 b ) then shows how the upper swage 5 draws the blank 6 , producing corresponding flange regions 6 a. The upper swage 5 extends in this case in the longitudinal direction to produce a half shell for a hollow profile, for example having a cross-sectional shape which varies in the longitudinal direction. In the operation shown in FIG. 1 c ), the blank holder 4 is lowered further, once the spacers 7 , 8 have been removed from the drawing die, so that on the one hand the flange region 6 a is trimmed via a cutting edge which is present on the blank holder 4 . On the other hand, the further movement of the blank holder 4 into the flange region 6 a shapes a corner by upsetting. The shaping of the corner into the flange region 6 a ensures that the surface of the edge of the half shell is shaped in accordance with the shape of the blank holder 4 and obtains a precisely defined contour. In the present exemplary embodiment, the surface of the axially extending edge of the half shell is brought by the blank holder 4 into a planar shape perpendicularly to the wall of the body of the deep drawn blank. At the same time, the upsetting of the walls of the body of the deep drawn blank equalises the stresses which are introduced into the blank during the deep drawing, so that there are almost no restoring moments in the deep drawn half shell. The upsetting according to the invention can therefore be used to produce low-springback half shells. FIG. 1 d ) shows the exemplary embodiment of the method according to the invention at the end of the operations in the drawing die after the upsetting of the flange region 6 a. In this position, the blank holder 4 and the upper swage 5 can then be drawn and the blank 6 removed from the drawing die with a flange region 6 a shaped substantially perpendicularly to the wall.
[0032] FIG. 1 e ) to 1 h ) show the further course of the first exemplary embodiment of the method according to the invention in a shearing die 2 . The shearing die 2 comprises a bottom swage 9 , two blank holders 10 , 11 and an upper upsetting/cutting swage 12 . Once the blank has been inserted into the shearing die 2 , the blank is fixed in its position by the blank holders 10 , 11 , as FIG. 1 e ) shows. The bottom swage 9 comprises a cavity 13 which is adapted to the upper cutting/upsetting swage 12 and into which the flange region 6 a is shaped during the trimming of the deep drawn blank. In this case, the upper cutting/upsetting swage 12 shapes into the flange region 6 a a reverse curve which is directed in opposition to the curve of the flange region after the deep drawing. The reverse curve serves on the one hand to facilitate the separating-off of the flange region. On the other hand, the reverse curve of the flange region and the upsetting process of the upper cutting/upsetting swage 12 provide a further reduction in stress in the trimmed half shell. Once, as FIG. 2 g ) shows, the upper cutting and upsetting swage 12 has deformed the flange region into the mould cavity 13 , the shearing die can be opened and a half shell 14 without margins removed in accordance with FIG. 1 h ). The half shell 14 without margins has, owing to the additional upsetting steps, almost no springback forces which are conventionally introduced into deep drawn parts via the deep drawing. Owing to the precisely defined geometry of the surface of the edge 15 of the half shell, said half shell is ideally suited to be welded to an appropriate other half shell to form a closed hollow profile.
[0033] FIG. 2 a ) to 2 d ) are schematic radial sectional views of an alternative embodiment of the shearing die during the carrying-out of a further exemplary embodiment of the method according to the invention. The shearing die 2 ′ has a bottom swage 18 , an upper cutting swage 16 and a blank holder 17 . The upper cutting swage 16 cuts in conjunction with the blank holder 17 the flange region 6 a, which is shaped so as to protrude perpendicularly as a corner, of the deep drawn blank, as FIGS. 2 a ) and 2 b ) show. After the trimming of the flange region 6 a, a relative movement of the bottom swage 18 and of the upper swage 19 with respect to each other in conjunction with the blank holder 17 additionally upsets the wall of the body of the deep drawn blank 6 , FIG. 2 c ). Subsequently, according to FIG. 2 d ), the shearing die 2 ′ can be opened and the half shell 14 removed. In contrast to the shearing die shown in FIG. 1 e ) to 1 h ), the upsetting of the wall of the deep drawn blank 6 and the shearing-off of the flange region 6 a from the deep drawn blank 6 are carried out separately from each other, so that additional flexibility is achieved with regard to the process parameters during the shearing-off and upsetting.
[0034] FIG. 3 a ) to f ) are schematic sectional views of the drawing die 1 ″ and the shearing die 2 ″ during the carrying-out of a third exemplary embodiment of the method according to the invention. In the third exemplary embodiment of the method according to the invention, the blank 6 is deep drawn and trimmed in a three-stage method. In contrast to the first exemplary embodiment of the method according to the invention, in which the deep drawing and upsetting of the flange regions perpendicularly to the wall of the deep drawn region of the blank are carried out in a single operation, two operations are required in the third exemplary embodiment illustrated in FIG. 3 . The simply held blank holder 20 of the drawing die 1 ″ serves, as may be seen from FIGS. 2 a ) and 2 b ), merely to hold the blank 6 during the deep drawing process. After the deep drawing of the blank 6 by the upper drawing swage 23 , which dips into the bottom swage 22 , the blank holder 20 is removed. An upper cutting swage 21 subsequently trims the edge region of the flange regions 6 a of the deep drawn blank, while the upper deep drawing swage 23 functions as a blank holder. Subsequently, the upper deep drawing swage 23 and a spacer 24 , which was used beforehand to form a bent flange region 6 a of the blank, are removed. The bent flange region 6 a allows particularly effective flowing of the material of the blank, thus improving the reshaping behaviour of the blank 6 . After the drawing of the spacer 24 and introduction of an additional upper upsetting swage 25 , the flange region 6 a is upset as a corner perpendicularly to the wall of the body of the deep drawn blank and trimmed in a shearing die 2 ″ via an upper cutting and upsetting swage 26 . The bottom swage 27 comprises, like the drawing die 2 used in the first exemplary embodiment of the method according to the invention, a mould cavity 28 which serves to introduce a reverse bend during the upsetting cut.
[0035] FIG. 4 a ) is then a schematic axial sectional view, as a fourth exemplary embodiment of the invention, of a closed hollow profile which is produced in accordance with the invention and consists of low-springback half shells. FIG. 4 b ) is a plan view of the same closed hollow profile 28 . The hollow profile 28 consists of two half shells 28 a and 28 b which are produced using the method according to the invention and joined together via a weld seam 29 . Preferably, the hollow profiles are welded in contour dies (not shown) which are for this purpose positioned relative to one another in such a way that the edges of the half shells 28 a and 28 b form a butt joint. The weld seam 29 can preferably be produced using a laser beam, wherein particularly precise positioning of the butt joint being required. As described hereinbefore, it is possible in particularly low-springback half shells 28 a, 28 b to use merely simple positioning pins (also not shown) as positioning means for positioning the half shells. Furthermore, alternative welding methods are also conceivable for welding the half shells 28 a and 28 b to each other.
[0036] FIG. 4 b ) additionally shows, in the plan view of the closed hollow profile 28 , the resilient hose 30 which is introduced into the hollow profile to eliminate any restoring forces and is acted on by a pressure medium to compensate for inwardly directed restoring moments. Outwardly, restoring forces are accommodated during the welding, for example by the contour die used for positioning. In the resilient hose, the regions of the weld seam are formed so as to be thermally protected and have for example a ceramic strip 31 . For the sake of simplicity, the dies in which the half shells are positioned for welding are not shown in FIG. 4 b ).
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A method for producing low-springback half shells made of a metal, in particular steel or a steel alloy, includes drawing in at least one drawing die a blank, such that the blanks have flange regions on the deep drawn body after the deep drawing. The flange regions are shaped by upsetting a corner substantially perpendicularly to a wall of the deep drawn region of the blank and the flange regions are subsequently trimmed in a shearing die, such that half shells without margins are produced.
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RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of U.S. Ser. No. 09/628,388, filed Aug. 1, 2000, now pending, which is a divisional of U.S. Ser. No 08/926,155, now issued as U.S. Pat. No. 6,096,331, which is a continuation-in-part of United States Ser., No 08/720,756, filed Oct. 1, 1996, now issued as U.S. Pat. No. 5,916,596, and U.S. Ser. No 08/485,448, filed Jun. 7, 1995, now U.S. Pat. No. 5,665,382, which is, in turn, a continuation-in-part of U.S. Ser. No 08/200,235, filed Feb. 22, 1994, now issued as U.S. Pat. No. 5,498,421, which is, in turn, a continuation-in-part of U.S. Ser. No 08/023,698, filed Feb. 22, 1993, now issued as U.S. Pat. No. 5,439,626 and U.S. Ser. No 08/035,150, filed Mar. 26, 1993, now issued as U.S. Pat. No. 5,362,478, the contents of each of which are hereby incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to novel formulations of pharmacologically active agents and methods for the delivery of such agents to subjects in need thereof.
BACKGROUND OF THE INVENTION
[0003] In the quest for next generation therapies to treat cancer, scientists often discover promising compounds only to find that the molecule is highly insoluble in water, and hence impossible to deliver intravenously. Such was the problem with paclitaxel, an extremely effective anti-tumor agent discovered over a quarter century ago by the National Cancer Institute. Despite almost 30 years of effort, the only method currently approved to address this problem of water-insolubility of paclitaxel is the use of a toxic solvent (cremophor) to dissolve the drug, and administer this solvent-paclitaxel mixture over many hours using specialized intra-venous tubing sets to prevent the leaching of plasticizers. This solvent-drug mixture, currently marketed in branded and generic forms, has become the most widely used anti-cancer agent as it has shown activity in breast, lung and ovarian cancer and is undergoing multiple clinical trials exploring its application in combination with other drugs for other solid tumors.
[0004] The cremophor formulation of paclitaxel is associated with significant side-effects including life-threatening allergic reactions requiring the need for steroid pre-treatment for every patient receiving the drug, and severe infections as a result of lowering of white blood cells requiring the need for expensive blood cell growth factors. Ultimately these toxicities result in dose-limitation of cremophor-based paclitaxel formulations, thus limiting the full potential of the very effective paclitaxel molecule.
[0005] While the above toxic side effects of cremophor paclitaxel formulations are well known, it has not been widely recognized by scientists in the field that the presence of cremophor creates a more serious impediment to realizing the maximal potential of paclitaxel by entrapping paclitaxel within the hydrophobic cores of cremophor micelles within microdroplets in the blood-stream. The entrapment effect of cremophor is dependent on cremophor concentration. Thus, increasing the doses of cremophor solutions of paclitaxel can potentially worsen the entrapment by raising the concentration of cremophor, leading to higher toxcities but none of the potential benefits of higher doses of paclitaxel, since much of the active molecule is unavailable to the intra-cellular space, where it is needed to act.
[0006] This entrapment of paclitaxel by cremophor has a profound effect on the intra-cellular availability of the active molecule and hence may have significant clinical implications in terms of clinical outcome. Accordingly, there is a need in the art for new formulations for the delivery of substantially water insoluble pharmacologically active agents, such as paclitaxel, which do not suffer from the drawbacks of cremophor.
BRIEF DESCRIPTION OF THE INVENTION
[0007] In accordance with the present invention, novel formulations have been developed which are much more effective for the delivery of hydrophobic drugs to patients in need thereof than are prior art formulations. Invention formulations are capable of delivering more drug in shorter periods of time, with reduced side effects caused by the pharmaceutical carrier employed for delivery.
BRIEF DESCRIPTION OF THE FIGURES
[0008] [0008]FIG. 1 collectively compares the plasma kinetics of radiolabelled paclitaxel when administered to a mouse model as part of a Taxol formulation (closed squares) or as part of in invention formulation (diamonds; ABI-007). FIG. 1A indicates plasma radioactivity measured up to 0.5 hours after administration. FIG. 1B indicates plasma radioactivity measured up to 24 hours after administration. Inspection of the figure reveals that 2-5 fold higher levels of paclitaxel are retained in the plasma up to 3 hours after administration when paclitaxel is administered in a cremophor-based formulation (Taxol). Due to the reduced rate of metabolism for ABI-007, plasma levels of paclitaxel are higher after 8 hours when administered in an invention formulation, relative to a cremophor-based formulation.
[0009] [0009]FIG. 2 compares the partitioning of paclitaxel between red blood cells and plasma when administered to a mouse model as part of a Taxol formulation (closed squares) or as part of in invention formulation (diamonds; ABI-007). Inspection of the figure reveals that the blood/plasma ratio for paclitaxel administered as part of a cremophor-based formulation (Taxol) in the first 3 hours after administration is about 1.5-2, indicating that the majority of paclitaxel is retained in the plasma due to micellar formation with cremophor. In addition, it is seen that paclitaxel in a cremophor-based formulation does not significantly partition into the red blood cells. In contrast, paclitaxel administered as part of an invention formulation readily partitions into the red blood cells.
[0010] [0010]FIG. 3 summarizes tumor/plasma partitioning kinetics of paclitaxel when administered to a mouse model as part of a Taxol formulation (closed squares) or as part of in invention formulation (diamonds; ABI-007). It is seen that the tumor/plasma ratio of paclitaxel increases significantly over the first 3 hours when as part of an invention formulation, as opposed to a Taxol formulation.
[0011] [0011]FIG. 4 compares the response of mammary carcinoma in a mouse model to exposure to ABI-007 or Taxol.
[0012] [0012]FIG. 5 compares the response of ovarian carcinoma in a mouse model to exposure to ABI-007 or Taxol.
[0013] [0013]FIG. 6 compares the response of prostate tumors in a mouse model to exposure to ABI-007 or Taxol.
[0014] [0014]FIG. 7 compares the response of colon tumors in a mouse model to exposure to ABI-007 or Taxol.
[0015] [0015]FIG. 8 compares the response of lung tumors in a mouse model to exposure to ABI-007 or Taxol.
DETAILED DESCRIPTION OF THE INVENTION
[0016] In accordance with the present invention, there are provided methods for the delivery of a substantially water insoluble pharmacologically active agent to a subject in need thereof, said method comprising combining said agent with an effective amount of a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, and administering an effective amount of said combination to said subject.
[0017] As readily recognized by those of skill in the art, a wide variety of pharmacologically active agents are contemplated for use in the practice of the present invention. A presently preferred agent contemplated for use herein is paclitaxel.
[0018] Pharmaceutically acceptable carriers contemplated for use in the practice of the present invention are biocompatible materials such as albumin.
[0019] Micelle-forming components which are preferably avoided in the practice of the present invention are surface active materials which are commonly used to assist in solubilizing substantially insoluble compounds in aqueous media, such as, for example, cremophor.
[0020] Invention combination of active agent and pharmaceutically acceptable carrier can be administered in a variety of ways, such as, for example, by oral, intravenous, subcutaneous, intraperitoneal, intrathecal, intramuscular, intracranial, inhalational, topical, transdermal, rectal, or pessary routes of administration, and the like.
[0021] In accordance with another embodiment of the present invention, there are provided methods to reduce entrapment of a substantially water insoluble pharmacologically active agent in vehicle employed for delivery thereof, said method comprising combining said agent with a pharmaceutically acceptable carrier which is substantially free of micelle-forming components prior to delivery thereof.
[0022] Presently preferred pharmaceutically acceptable carriers contemplated for use herein are those having substantially lower affinity for said agent than does the micelle-forming component. Thus, for example, while cremophor has the benefit of aiding in the solubilization of agent, it has the disadvantage of having a substantial affinity for the agent, so that release of the agent from the carrier becomes a limitation on the bioavailability of the agent. In contrast, carriers contemplated herein, such as, for example, albumin, readily release the active agent to the active site and are thus much more effective for treatment of a variety of conditions.
[0023] In accordance with yet another embodiment of the present invention, there are provided methods to reduce entrapment of a substantially water insoluble pharmacologically active agent in vehicle employed for delivery thereof, said method comprising employing pharmaceutically acceptable carriers which are substantially free of micelle-forming components in aqueous media as the vehicle for delivery of said agent.
[0024] In accordance with still another embodiment of the present invention, there are provided methods to prolong exposure of a subject to a substantially water insoluble pharmacologically active agent upon administration thereof to a subject in need thereof, said method comprising combining said agent with pharmaceutically acceptable carrier(s) which is (are) substantially free of micelle-forming components prior to delivery thereof.
[0025] In accordance with a further embodiment of the present invention, there are provided methods to facilitate transport of a substantially water insoluble pharmacologically active agent across cell membranes upon administration thereof to a subject in need thereof, said method comprising combining said agent with pharmaceutically acceptable carrier(s) which is (are) substantially free of micelle-forming components prior to delivery thereof.
[0026] In accordance with a still further embodiment of the present invention, there are provided methods to facilitate transport of a substantially water insoluble pharmacologically active agent into the cellular compartment upon administration thereof to a subject in need thereof, said method comprising combining said agent with pharmaceutically acceptable carrier(s) which is (are) substantially free of micelle-forming components prior to delivery thereof.
[0027] In accordance with another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation provides a higher concentration of said agent in the cellular compartment than a formulation of the same agent with a micelle-forming component.
[0028] In accordance with yet another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation provides increased intra-cellular availability of said agent relative to a formulation of the same agent with a micelle-forming component.
[0029] In accordance with still another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation provides prolonged activity of said agent relative to a formulation of the same agent with a micelle-forming component.
[0030] In accordance with a further embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation facilitates delivery of said agent to red blood cells.
[0031] In accordance with another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation releases a portion of said agent contained therein to the lipid membrane of a cell.
[0032] In accordance with yet another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation provides reduced levels of said agent in the bloodstream relative to a formulation of the same agent with a micelle-forming component.
[0033] In accordance with still another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation delivers said agent to the bloodstream over an extended period of time relative to a formulation of the same agent with a micelle-forming component.
[0034] In accordance with a further embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein the rate of metabolism of said agent in said formulation is reduced relative to the rate of metabolism of said agent in a formulation with a micelle-forming component.
[0035] In accordance with another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said agent has a longer half life in said formulation relative to the half life of said agent in a formulation with a micelle-forming component.
[0036] In accordance with yet another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation provides a higher red blood cell/plasma ratio of said agent than does a formulation of the same agent with a micelle-forming component.
[0037] In accordance with still another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation provides a higher tumor/plasma ratio of said agent than does a formulation of the same agent with a micelle-forming component.
[0038] In accordance with a further embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein the area under the curve for delivery of said agent to a tumor via said formulation is higher than the area under the curve for delivery of said agent to a tumor via a formulation of the same agent with a micelle-forming component.
[0039] In accordance with a still further embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation provides a higher concentration maximum (C max ) for said agent in tumor cells than does a formulation of the same agent with a micelle-forming component.
[0040] In accordance with another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation provides a lower concentration maximum (C max ) for said agent in plasma than does a formulation of the same agent with a micelle-forming component.
[0041] In accordance with still another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation provides more rapid uptake of said agent by tumor cells than does a formulation of the same agent with a micelle-forming component.
[0042] In accordance with yet another embodiment of the present invention, there are provided formulations comprising a substantially water insoluble pharmacologically active agent and a pharmaceutically acceptable carrier which is substantially free of micelle-forming components, wherein said formulation enhances delivery of said agent to tissue, relative to a formulation of the same agent with a micelle-forming component.
[0043] Tissues contemplated for treatment according to the invention include tumors, peritoneal tissue, bladder tissue, lung tissue, and the like.
[0044] ABI-007 is a proprietary, cremophor-free, albumin-based paclitaxel nanoparticle, {fraction (1/100)} th the size of a single red blood cell. Based on several Phase I studies, it has been shown that ABI-007 can be administered rapidly without the need for steroid pre-treatment and without the need for G-CSF at a maximum tolerated dose of 300 mg/m 2 given every 3 weeks. This is a significantly higher dose than is approved for cremophor-based paclitaxel formulations (Taxol) of 175 mg/m 2 .
[0045] In accordance with the present invention, it has been discovered that ABI-007 acts as a novel biologic nano-transporter for hydrophobic drugs such as paclitaxel, with the capabilities of rapidly releasing paclitaxel to the cellular compartment and increasing intra-cellular availability of the active drug, where it is needed in order to have its chemo-therapeutic effect. Furthermore, through the use of the red blood cell as a secondary storage vehicle it has been discovered that in addition to the rapid and increased availability of paclitaxel at the intra-cellullar level, by the recruitment of circulating red blood cells, ABI-007 further provides a significant prolonged activity of the parent molecule with sustained in-vivo release. These novel mechanisms for rapid and increased intra-cellular availabilty of the drug at the tumor site, together with sustained trafficking of the non-metabolized paclitaxel, has potentially significant implications for the clinical outcome in the treatment of solid tumors. Indeed, the pre-clinical and Phase II clinical data presented below supports this notion.
[0046] By taking advantage of the differences in binding affinities of albumin and the lipid bi-layer of cell membranes for hydrophobic paclitaxel, the drug-bearing albumin nanoparticle (ABI-007) would rapidly release a portion of its hydrophobic paclitaxel cargo to the lipid membrane of a cell.
[0047] In the vascular compartment, the first cell encountered is the red blood cell. In accordance with the present invention, the red blood cell has been found to rapidly compartmentalize the paclitaxel molecule. Since the red blood cell has no nucleus and hence no microtubulin to which the paclitaxel molecule can bind, nor any degradation machinery within its core, this cell serves as an ideal secondary storage vehicle for the active paclitaxel, accounting in part for the prolonged activity of paclitaxel noted with ABI-007.
[0048] Following partitioning of a portion of its paclitaxel payload to the circulating red blood cells, the nanoparticle is carried by the blood-stream to the hypervasular tumor, where paclitaxel is rapidly transferred to the tumor cell-membrane, again due to the differences in binding affinity. It has been well established by other groups that the hydrostatic pressure within these tumor cells is abnormally higher than the surrounding interstitium and vascular space. This abnormally high pressure, together with the fact that the vessels associated with tumors are also abnormally leaky, creates a barrier to the delivery of chemotherapeutic agents to the tumor cell. Thus, under these circumstances it is imperative that the hydrophobic paclitaxel be released rapidly to the lipid cell membrane and be bound by the microtubules within the nuclues before the drug is ejected from the tumor. Evidence presented herein indicates that ABI-007 provides that opportunity by the ability to rapidly release the hydrophobic molecule. In contrast, cremophor-based formulations entrap the paclitaxel, limiting the ability of the drug to partition into cells. This difference may have important clinical implications and may account in part for the positive data noted in the Phase II studies of ABI-007 in metastatic breast cancer and the evidence for responses in patients who had previously failed Taxol therapy
[0049] As the nanoparticle depeletes itself of paclitaxel into the cellular compartment within the first 3-8 hours following infusion, the plasma concentartion of paclitaxel diminshes. At this juncture, paclitaxel (still in its active, non-metabolized form) follows the concentration gradient and is now transferred to albumin again, and is again carried to the tumor bed. Thus, a prolonged half-life of paclitaxel has been achieved, with sustained release and ultimately higher tumor concentration of the drug.
[0050] The invention will now be described in greater detail by reference to the following non-limiting examples.
EXAMPLE 1
Preclinical Studies Confirm the Modulation of Paclitaxel Release by the Protein Nanosphere and Increased Efficacy of Equi-Dose of ABI-007 vs Taxol
[0051] Using radio labeled paclitaxel, the enahanced intra-cellular availability of paclitaxel has been confirmed following injection of ABI-007. In addition, the entrapment of Cremophor-bound paclitaxel has also been confirmed. This difference in findings correlates with in-vivo studies in mice bearing human breast cancer, with the finding that ABI-007 at equi-dose to Taxol, resulted in improved outcomes that these 130 nanometer size particles distributed throughout the body.
[0052] Thus, human MX-1 mammary tumor fragments were implanted subcutaneously in female athymic mice. Radiolabelled drug was administered when tumors reached about 500 mm 3 . Tritium-labelled ABI-007 or tritium-labelled Taxol were administered at a dose of 20 mg/kg. Both groups received about 7-10 μCi/mouse of tritium-labelled paclitaxel. Saline was used as the diluent for both drugs. At various time points (5 min, 15 min, 30 min, 1 hr, 3 hr, 8 hr and 24 hr), 4 animals were sacrificed, then blood samples and tumor were recovered for radioactivity assessment.
[0053] Radioactivity was determined as nCi/ml of whole blood and plasma, and nCi/g of tumor tissue. Results are presented in FIGS. 1, 2 and 3 , and are standardized for radioactivity and paclitaxel dose. The data from these studies are also presented in the following tables.
PHARMACOKINETIC PARAMETERS FOR WHOLE-BLOOD, PLASMA AND TUMOR DISTRIBUTION OF 3 H-PACLITAXEL IN ABI-007 VS TAXOL New AUC 0-inf (nCi hr/mL or g) AUC 0-24 (nCi hr/mL or g) C max (nCi/mL or g) Blood Plasma Tumor Blood Plasma Tumor Blood Plasma Tumor ABI-007 939 1161 5869 ABI-007 656 836 2156 ABI-007 328 473 144 Taxol 871 1438 3716 Taxol 849 1415 1804 Taxol 752 1427 117 Ratio 1.08 0.81 1.58 Ratio 0.77 0.59 1.20 Ratio 0.44 0.33 1.23 TAXOL: high Plasma AUC—paclitaxel is trapped in ABI-007: Substantially lower Cmax in Plasma, blood cremophor micelles implies rapid distribution into cells and tissues ABI-007: higher Tumor AUC (exposure), pac ABI-007: higher Tumor Cmax—more effective tumor kill distributed into cells/tissues t max (hours) t½ e (hours) Vdss (mL/kg) Blood Plasma Tumor Blood Plasma Tumor Blood Plasma Tumor ABI-007 0 0 0.5 ABI-007 17.1 16.1 40.2 ABI-007 6939 5180 NA Taxol 0 0 3 Taxol 4.0 3.3 24.1 Taxol 1409 692 NA Ratio 4.28 4.88 1.67 Ratio 4.92 7.49 ABI-007: Substantially lower ABI-007: Prolonged half life ABI-007: Substantially higher tumor tmax indicates rapid relative to Taxol in blood, plasma volume of distribution indicating uptake of paclitaxel into tumor and tumor may result in higher extrensive distribution into tissues relative to taxol antitumor activity relative to Taxol
[0054] Further studies demonstrate that after 24 hours, the active ingredient of the parent molecule, paclitaxel, remains present in the bloodstream, at double the concentration of Taxol. In studies comparing radiolabelled paclitaxel in Taxol vs ABI-007, direct measurements reveal increased and prolonged levels of paclitaxel in the tumors of animals receiving ABI-007.
EXAMPLE 2
Toxicity Studies
[0055] Toxicity was assessed for Taxol, cremophor and ABI-007. ABI-007 was found to be 50-fold less toxic than Taxol, and 30-fold less toxic than the cremophor vehicle alone, as illustrated in the following table:
Agent LD 50 , mg/kg Taxol 9.4 Cremophor 13.7 ABI-007 448.5
EXAMPLE 3
In vivo Tumor Xenografts
[0056] Human tumor fragments were implanted subcutaneously in female athymic mice. Treatment was initiated when tumors reached about 150 mm 3 . The mice received either CONTROL (saline), ABI-007 (4 dose levels: 13.4, 20, 30 and 45 mg/kg) or TAXOL (3 dose levels: 13.4, 20, and 30 mg/kg) administered I.V. daily for 5 days. Saline was used as the diluent for both drugs.
[0057] Determination of Equitoxic dose or MTD: The Equitoxic dose or MTD for each drug was determined by satisfying one of the following criteria:
[0058] a) Dose for each drug that resulted in similar body weight loss (<20%) if no deaths were seen;
[0059] b) If body weight loss could not be matched, the highest dose at which no deaths were seen;
[0060] If neither a) nor b) could be satisfied, the lowest dose that resulted in similar death rate.
[0061] Tumor response to the drugs was compared at the Equitoxic dose or MTD established as above. Results for several different tumor types are presented in FIGS. 4 - 8 .
EXAMPLE 4
Clinical Studies
[0062] i. Entrappment of Paclitaxel by Cremophor
[0063] Working independently at Rotterdam Cancer Institute, Dr Alex Sparreboom has reported in a series of pharmacokinetic studies involving patients receiving Taxol that cremophor “causes a profound alteration of paclitaxel accumulation in erythrocytes in a concentration-dependant manner by reducing the free drug fraction available for cellular partitioning.” He has further found that the drug trapping occurs in micelles and that these micelles act as the principal carrier of paclitaxel in the systemic circulation. Since that publication these findings have been independently confirmed by two other groups.
[0064] ii. Improved Clinical Activity With ABI-007
[0065] Data from Phase II shows both increased effiacacy in metastatic breast cancer patients. When compared to the published literature of response rates to Taxol, the study results showed a dramatic difference in both response rates and time of response as well as evidence of reduced toxicities associated with ABI-007. Further details can be obtained by reviewing the posters presented at ASCO.
[0066] Although the present invention has been described in conjunction with the embodiments above, it is to be noted that various changes and modifications are apparent to those who are skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention defined by the appended claims.
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In accordance with the present invention, novel formulations have been developed which are much more effective for the delivery of hydrophobic drugs to patients in need thereof than are prior art formulations. Invention formulations are capable of delivering more drug in shorter periods of time, with reduced side effects caused by the pharmaceutical carrier employed for delivery.
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BACKGROUND OF THE INVENTION
This invention relates generally to body belts, harnesses, and the like which are worn by workers to prevent falls. More particularly, the present invention relates to safety devices having one or more lanyards which connect or tie off with a fixed object.
In hazardous occupations and work conditions, body belts and body harnesses have long been employed by workers to reduce the potential for serious falls. Such body belts and body harnesses come in a wide variety of styles, types and configurations. Conventionally, a safety belt is secured around the waist of the worker. A lanyard connects to the safety belt for securement around a fixed object. A number of conventional body belts to which the invention relates, employ generally D-shaped pivotal ring members which are connected to the belt wrapped around the worker's waist. The lanyard is then connected between the pivotal D-ring members. Releasable snap hooks which employ a releasable keeper securable in a locked position, are attached at the ends of the lanyard and are engageable with the D-ring member for connecting the lanyard back into the body belt.
Despite a number of designed safety features of conventional body belts, the connection of the lanyard to the body belt is not always feasible or desirable. Connecting to other than a D-ring may present a potential for accidental disengagement. Under certain unusual and intense load conditions, it is possible that conventional lanyards connected to other than a D-ring may encounter a "roll-out" condition due to the positioning of the lanyard line over the snap hook safety mechanism. While "roll-out" conditions are quite infrequent and can be prevented by the worker observing certain safety precautions, the consequences of an actual "roll-out" condition are potentially life threatening.
SUMMARY OF THE INVENTION
Briefly stated, the invention, in a preferred form, is a safety restraint device which employs a safety belt for attachment around the waist of an individual. A safety lanyard connects with the safety belt. The safety lanyard includes a flexible cable or rope for attachment to a fixed object. A snap hook, including a releasable safety keeper, is attached at the end of the cable for securing the lanyard. A sliding ring is mounted to the lanyard for slidable positioning along the cable. The ring comprises a connector sleeve which defines a longitudinal channel for slidably receiving the cable. A generally D-shaped ring extends from the connector sleeve. The ring is dimensioned so that the hook may be attached to the D-ring, but that the likelihood of roll out is minimized. The lanyard is wrappable around the fixed secure object and the hook is engageable with the D-ring to secure the lanyard to the fixed object.
The connector sleeve includes enlarged tapered end portions so that the ends of the connector sleeve do not overly strain the lanyard cable during a fall or other loading conditions. The channel wall portions of the sleeve are also finished to alleviate undue abrasion between the lanyard cable and the connector sleeve.
An object of the invention is to provide a new and improved safety restraint device.
Another object of the invention is to provide a new and improved mechanism for securing a safety restraint device lanyard around a fixed object.
A further object of the invention is to provide a new and improved safety restraint device which minimizes "roll-out" of the connector hook of the lanyard.
A yet further object of the invention is to provide a new and improved safety restraint device having an extended range of "tie off" positions and allowing for increased worker mobility by reducing the need to have the lanyard connected back to the belt mounted D-ring.
Other objects and advantages of the invention will become apparent from the drawings and the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an elongated unsecured configuration of safety restraint device in accordance with the present invention;
FIG. 2 is an enlarged side elevational view, partly in phantom, of a sliding D-ring connector employed in the safety restraint device of FIG. 1;
FIG. 3 is a top plan view of the D-ring connector of FIG. 2; and
FIG. 4 is a perspective view of the safety restraint device of FIG. 1 illustrated in a selected operable mode.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the drawings wherein like numerals represent like parts throughout the figures, a safety restraint device incorporating the improvement of the present invention is designated generally by the numeral 10. Safety restraint device 10 comprises a belt 20 which is secured around the waist of an individual. The safety device is connected and/or tied off to a fixed object 100 (schematically illustrated) to prevent the wearer from accidentally falling or to greatly limit any free fall should the wearer accidentally slip. The invention has applicability in connection with a wide variety of safety body belts, harnesses, and the like. It should be appreciated that the specific body belt 10 of FIG. 1 is illustrated for purposes of describing the invention and is not a limitation of the applicability or the scope of the improvement of the present invention.
Safety belt 12 includes a rugged reinforced inner belt 20 which is formed of heavy-duty woven, multi-ply webbing material. An outer narrower webbing strip 22 connects with the inner belt and extends circumferentially therewith in overlapping relationship. The outer strip 22 is securely stitched to the inner webbing of the inner belt 20 along the back portion thereof. A leather lining 24 is stitched at the inner surface of the outer webbing strip 22 and wrapped around one end portion thereof and stitched in place. A co-linear series of openings 26 extend through the outer webbing strip 22 and the leather lining 24. Brass rivets may be stamped into the openings. The opposing end of the webbing strip 22 secures a belt buckle 30 of heavy-duty form which is engageable in a selected opening 26. A belt loop 32 is also secured by the outer webbing. A forward interiorly projecting leather loop 34 is dimensioned to receive the inner belt 20 so that the inner belt extends therethrough and the webbing strip may be buckled in a conventional manner.
A pair of heavy-duty metal D-shaped ring members 40 and 50 are mounted for pivotal positioning at spaced positions along the body belt. The D-ring members include respective connector shafts 42 and 52 which extend in generally perpendicular relationship to the longitudinal axis of the body belt. Cylindrical wear pads 44 and 54 are wrapped around the shafts. The webbing strip 22 is secured to the inner belt 20 to for loops which connect the D-rings to the body belt.
A safety lanyard 60, which may be either a steel cable or a cable having a fibrous rope-like composition, is wrapped around D-ring member 40 and spliced in place. A thimble 62 is preferably interposed around the D-ring member at the inside of the splice loop for preventing excessive abrasion which would tend to fray or weaken the fibers or wires. It should be appreciated that the D-ring members 40 and 50 are freely pivotal and have an orientation which is perpendicular to the longitudinal axis of the safety belt.
The free end of the lanyard 60 connects with a hook 70 through a ring 72. The lanyard is spliced around a thimble 64 which loops the ring 72. The thimble 64 also functions to prevent excessive abrasion of the metal ring against the lanyard cable. A spring-loaded keeper 74 is biased to enclose the eye of the hook. A release lever 76 is also mounted to the hook. The release lever 76 includes a projecting tab 77 which interferes with the keeper to prevent release of the keeper. The lever is manually depressible so that the tab 77 passes through a slot 78 of the keeper for releasing the keeper from the safety closed position. The hook 70 may be engaged by forcing the D-ring member 50 into the eye of the hook against the bias of the keeper. The keeper then biases to the closed position and the release latch is biased to pivot to prevent release of the keeper.
With additional reference to FIGS. 3 and 4, a sliding generally D-shaped ring 80 includes an integral connector sleeve 82 which defines a longitudinal channel 84. The D-ring is made of a rugged metal material such as steel. The end portions of the channel have flared tapered openings 86 and 88. The channel is generally uniformly dimensioned so that the lanyard cable may be slidably extended therethrough for mounting the D-ring 80 to the lanyard 60. The flared openings 86 and 88 prevent cable fraying and excessive abrasive forces against the lanyard cable. In addition, the inner portion of the channel has a smooth finish to prevent undue frictional abrasion against the freely slidable lanyard cable.
The sliding D-ring 80 is dimensioned so that the hook 70 is engageable therewith and the keeper 74 locks the hook to the sliding D-ring. In one mode of the invention, the safety restraint device is mounted to the wearer by securing the safety belt 12 in place. With reference to FIG. 4, the lanyard 60 is then wrapped around a fixed object 100 (which ordinarily should be capable of supporting a dead weight of 5,400 pounds) and is secured back to the lanyard through the sliding D-ring 80. The sliding D-ring functions in a fashion which prevents the "roll-out" condition where the lanyard cable engages the snap hook as may occur under certain unusual conditions with the conventional tying back of the lanyard to D-ring member 50 or other connector.
The lanyard cable is preferably relatively short, such as on the order of a few feet, so that should a wearer accidentally fall, the free fall will be limited. For some applications, it may not be possible to connect the hook 70 with the sliding D ring 80. In the latter case, the hook is connected in a conventional fashion to the fixed pivotal D-ring member 50. The sliding D-ring 80 is then simply left in a free condition. It should be appreciated that the sliding D-ring 80 and the hook 70 are configured so that the safety snap hook does not disengage without manual release and disengagement. The lanyard may also be configured to have a hook 70 on both ends with one hook connecting D-ring member 40.
In some embodiments an O-shaped or quasi O-shaped ring or rings may be employed rather than the described D-shaped rings.
While a preferred embodiment of the invention has been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention.
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A safety restraint device, such as worn by a worker for preventing falls, employs a sliding D-shaped ring which is mounted to the safety lanyard. The releasable snap hook of the safety lanyard may be engaged in the sliding D-ring to secure the safety lanyard to a fixed object.
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FIELD OF THE INVENTION
The present invention relates to a spinning device and, more particularly, to a spinning device with an inlet opening for a drafted sliver, a sliver guide and a hollow spindle for guiding the formed and drawn-off yarn, wherein means for generating an airflow are provided in the area of the sliver guide and the spindle, which acts on the fibers of the drafted sliver for twisting them.
BACKGROUND OF THE INVENTION
A device for producing a twisted yarn is known from German Patent Publication DE 40 36 119, wherein a guide member is arranged inside a nozzle block. A sliver traveling out of a drafting arrangement is drawn into the nozzle block and, near the inlet opening of a spindle, is subjected to an airflow rotating around the sliver for twisting it in this manner. A fiber strand guide takes the place of the inner fibers of the sliver as a so-called false core, because of which the fibers on the exterior circumferential surface of the fiber strand guide are forced to move along toward the inlet opening. In the course of this, the fibers are subjected to the action of the rotating airflow in an uncontrolled manner. Only the fiber strand guide arranged in the interior of the sliver counters an interfering false twist running out of the rotating area of the spindle in the direction toward the location where the sliver exits between the front rollers of the drafting arrangement. Subsequently the sliver is aspirated into the spindle by means of a suction airflow in order to create a yarn in this way.
Continuously increasing demands in regard to productivity and yarn properties are made on modern spinning machines.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to improve the device for sliver guidance in the type of spinning device described above in such a manner that an improved manufacturing process becomes possible.
In accordance with the invention, the sliver guide is comprised of fiber guide elements, which are spaced apart from each other and permit the free passage of a portion of the fibers constituting a core fiber bundle and the sliver guide is arranged outside of an imaginary center line of the traveling sliver such that at least a portion of the fibers is passed along the inward surface of the sliver guide. The spinning device can be designed such that the core fiber bundle is not deflected in the course of the passage of the sliver through the sliver guide. It is possible to achieve high production speeds with such an embodiment. Advantageously, the core fiber bundle includes at least 10%, preferably 20% to 40%, of the fibers. A good grasp and good guidance of the sliver between the fiber guide elements is achieved by means of the inner surface of the fiber guide elements, which is in contact with the sliver. In this manner, it is possible to divide the portions of the core and the sheath structures in a controlled manner into fibers which are oriented parallel in the longitudinal direction and into twisted fibers, wherein the core fibers only constitute a defined portion. The uncontrolled spreading away of fibers and fiber ends, as well as the continuation of the twisting in the direction toward the outlet of the sliver between the front rollers of the drafting arrangement is effectively prevented.
It is possible to improve the arrangement of the fibers which are oriented parallel in the longitudinal direction, and thereby the yarn properties, by means of yarn guide elements forming the core yarn bundle. An increase of the production speed is made possible at the same time.
In a further advantageous aspect of the invention, at least a portion of the fiber guide elements is embodied as a flat plate, by means of which it is possible to achieve a greater effect on the sliver. Alternatively, at least a portion of the fiber guide elements is preferably embodied to be needle-shaped. This permits the application of a particularly low pressure on the sliver. Fiber guide elements produced as flat plates or as needle-shaped can be easily manufactured. An embodiment of the fiber guide elements as parts of a single body, in which the fiber guide elements are made by cutting openings into a hollow cone, can also be simply and therefore cost-effectively produced and permits an improvement in the yarn values, particularly at high production speeds. The cutting of openings can be performed by erosion or drilling.
The embodiment can also be in the form of a compact sliver guide device with a sliver passage and fiber guide elements, wherein the sliver guide device is made of one piece. Simple handling and an easy and fast exchangeability are made possible because of the compact, one-piece design.
In a preferred embodiment, the fiber guide elements are arranged evenly distributed around the sliver, in particular concentrically or symmetrically, and the minimum distance of the fiber guide elements from the imaginary center line of the traveling sliver is slightly less than half the diameter of the sliver. Advantageously at least three fiber guide elements act on a single sliver. Such arrangements permit a specific metering or an increase of the guide and holding effects. The fiber guide elements preferably have the same shape in order to achieve as uniform an effect as possible distributed over the circumference of the sliver.
The inlet opening is preferably embodied as a slit-shaped sliver passage at least at the outlet side of the sliver, on whose oppositely located longitudinal sides the fiber guide elements are arranged, wherein the fiber guide elements extend at least approximately parallel in relation to the imaginary center line of the sliver, so that they cover a portion of the fiber flow from the sliver passage to approximately the vicinity of the inlet opening of the spindle and therefore remove it to the greatest possible extent from the effect of the rotating airflow. The retention of a core fiber bundle with primarily parallel and longitudinally oriented fibers in a largely undisturbed arrangement is made possible in this manner. By means of the spinning device in accordance with the invention, it is possible to achieve yarn speeds of 300 m/min and more, and therefore high productivity. Increased yarn strength and therefore an increased value of the finished yarn is also possible. A lower value can be selected for the pressure of the compressed air provided by the compressed air source. With the multitude of spinning stations in a modern spinning machine, a reduced air pressure leads to considerable cost reduction in the yarn production.
The fiber guide elements advantageously follow in the fiber flow direction immediately after the sliver passage and are arranged to be respectively centered on the longitudinal sides of the sliver passage, as viewed across the width of the sliver passage. The inside surfaces of the fiber guide elements facing the sliver extend in the direction of the fiber flow or in the direction of the respective free end of the fiber guide elements toward the center of the sliver, and the fiber guide elements have their smallest distance from each other at their free ends, by means of which the insertion of the sliver is made easier and the guidance of the passing sliver is improved.
The fiber guide elements are preferably designed resiliently such that, in case of an increase of the pressure exerted by the sliver on the inner surfaces of the fiber guide elements, they can be deflected transversely in relation to their extension. The free ends of the fiber guide elements oriented in the direction of movement preferably extend toward each other and have their smallest distance from each other at their free ends, but without touching each other. Advantageously, the fiber guide elements are designed such that their cross section increases toward the free ends. In this case, the core fiber bundle can extend centered on the imaginary axis of the device, and the imaginary center line of the sliver and the axis of the device can coincide. The insertion and the passage of the sliver is made easier by such an embodiment, and the guidance of the passing sliver is improved.
The position of the fiber guide elements is preferably adjustable and can be selected in accordance with the requirements of the spinning operation being performed. In particular, the distance between the free ends of the fiber guide elements and the inlet opening of the spindle is 0.2 mm to 0.7 mm. In this manner, a definite control, both of the effect and also the effective range, becomes possible in a particularly simple manner. The yarn formation can be advantageously affected and varied by means of such an embodiment and change of the position of the fiber guide elements.
By means of the device in accordance with the invention, high productivity is possible at high yarn speeds of more than 300 m/min and with increased yarn strength. The spinning device can be cost-effectively manufactured and operated.
Further details, features and advantages of the present invention will be understood from exemplary embodiments described in following specification with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a spinning device in accordance with the present invention depicted in a longitudinal section,
FIG. 2 is a plan view of the spindle head of the spinning device of FIG. 1 viewed in the longitudinal direction,
FIG. 3 is a partial view of the spinning process of the spinning device of FIG. 1 viewed in the area of the fiber guide elements and the spindle head,
FIG. 4 is another partial view of the spinning process like that of FIG. 3 with the spindle head shown in longitudinal section to illustrate the spun yarn produced,
FIG. 5 is a perspective representation of the spindle head and fiber guide elements, partially broken away, depicting the principle of the spinning process,
FIG. 6 is a schematic representation of a second embodiment of the fiber guide elements,
FIG. 7 shows the embodiment in FIG. 6 in an end view as seen in the direction of the arrows of FIG. 6,
FIGS. 8 and 9 are schematic representations of further embodiments of the fiber guide elements,
FIG. 10 is a view in longitudinal section of a spinning device of the invention having fiber guide elements which constitute a unit together with a fiber guide body,
FIG. 11 is another longitudinal sectional view of a spinning device of the invention schematically showing an embodiment of a sliver guide with a slit-shaped sliver passage,
FIG. 12 is an enlarged view of the fiber guide elements of the embodiment in accordance with FIG. 11, shown in longitudinal section,
FIG. 13 is another enlarged cross sectional view of the fiber guide elements of the embodiment of FIG. 11 taken along section line I—I thereof, and
FIG. 14 is a plan view of the embodiment of the fiber guide elements of FIG. 13 in a plan view as seen along line II—II thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The spinning station 1 represented in FIG. 1 has a housing 2 , at the end of which a disk 3 is arranged, facing two front rollers 4 , 4 ′ of a drafting arrangement. A nozzle device 7 , maintained by a holding ring 6 , is disposed around an axis 8 in the interior of the housing 2 between the disk 3 and a receiving body 5 . In the representation of FIG. 1, the axis 8 coincides with the center line 9 of the passing sliver 10 . A sliver passage 11 leads from the inlet side of the housing 2 along the center line 9 through the center of the disk 3 . From the sliver passage 11 , a transition takes place through a widening conical area into an area within the nozzle device 7 and the receiving body 5 which is initially cylindrical and then also conically widens. A hollow spindle 13 with a spindle head 15 , which conically tapers in the direction toward the spindle inlet opening 14 , projects in the conically designed hollow space 12 of the receiving body 5 and the nozzle device 7 . A ring-shaped portion of the hollow space 12 remains between the spindle 13 and the nozzle device 7 , as well as the receiving body 5 .
A fiber guide, formed by fiber guide elements 16 , is fastened on the disk 3 , with the fiber guide elements 16 extending obliquely inwardly inclined in relation to the fiber movement direction toward the center line 9 . An air chamber 17 is located between the housing 2 and the holding ring 6 . Toward the outside, the air chamber 17 is connected via a bore 18 with an air source, not represented for reasons of simplicity, and toward the inside the air chamber 17 is connected via further bores 19 with a ring-shaped air channel 20 . The nozzle device 7 is provided with four air nozzles 21 , which connect the air channel 20 with the sliver passage 11 and at the outlet into the sliver passage 11 are directed in a tangential orientation toward an area located between the fiber guide elements 16 and the spindle inlet opening 14 . The compressed air supplied by the air source flows via the air chamber 17 into the ring-shaped air channel 20 , is subsequently expelled out of the air nozzles 21 , and in this manner generates an airflow, which rotates at high speed around the sliver 10 directly at the spindle inlet opening. After the rotating passage of the ring-shaped portion of the hollow space 12 , this airflow is conducted into the chamber 22 and further to an opening, also not represented, in the housing 2 , through which it exits. At the same time, the airflow generates a suction airflow, which moves along with the sliver 10 , exiting at a nip location 23 between the front rollers 4 , 4 ′, through the inlet opening 24 and the sliver passage 11 into the hollow space 12 , and which is continued by a suction air flow generated by a vacuum source, not represented.
The sliver 10 , which is drafted in the drafting arrangement, is fed by the front rollers 4 , 4 ′ to the spinning station 1 and, assisted by the suction airflow effective upstream of the guide channel, is drawn into the central inlet opening 24 of the disk 3 and therefrom into the sliver passage 11 . The inclination of the fiber guide elements 16 , which are embodied in a needle shape, is directed inwardly in the direction toward the axis 8 and toward the sliver 10 , and makes the insertion and guidance of the traveling sliver 10 easier.
Further details can be understood from FIGS. 2 to 5 . The fiber guide elements 16 can exert a slight pressure on the sliver 10 , which in this case is slightly deformed, as represented in FIG. 2 . By means of this guidance of the sliver 10 , which acts in a sort of interlocking manner, the propagation of twisting in the sliver 10 past the area located between the guide elements 16 and the spindle inlet openings 14 in the direction toward the front rollers 4 , 4 ′ of the drafting arrangement is effectively stopped.
If the rear end of a fiber 25 in the area of the airflow rotating around the moving sliver 10 moves outside of the covering effect of the fiber guide element 16 , it is fully exposed to the force of the airflow coming out of the air nozzles 21 and is lifted, or respectively released, from the surface of the sliver 10 . The other end of the fiber 25 is not released. It is subjected to a rotation and is already inserted into the hollow spindle 13 and in this way removed from the direct effect of the airflow. Released free fiber ends are twisted around the spindle inlet opening 14 , as well as the conical spindle head 15 , by the rotating airflow and aided by the suction airflow effective in the hollow space 12 , as represented in FIG. 3 . The twisting can take place in several windings.
The rear free ends of the fibers 25 are continuously drawn in by the movements of the sliver 10 which, in the representation in FIGS. 1 and 2, takes place from left to right, and in the process a helical twisting of the sliver 10 takes place because of the free ends. The production principle of such a yarn 26 is illustrated in FIG. 4 .
The portions of the core and sheath structures in the cross section of the yarn 26 have been divided in this way into fibers which are oriented parallel in the lengthwise direction and into twisted fibers, wherein the core fibers, which are oriented in the lengthwise direction, only constitute a small part of the yarn 26 . True twisting is maintained in the yarn 26 .
The principle of the explained spinning process can be seen in a simplified perspective representation in FIG. 5 . In the representation in FIG. 5, the path of the sliver 10 , and respectively of the spun yarn 26 , extends linearly and horizontally and is indicated by the center line 9 . After passing through the nozzle device 7 and the fiber guide elements 16 , the sliver 10 is subjected to the effects of the airflow, which is directed in the direction of the broken line arrow, and it is drawn off as the spun yarn 26 by means of the spindle 13 .
FIGS. 6 and 7 show other embodiments of fiber guide elements 27 in the form of triangular plates. The fiber guide elements 27 , which are symmetrically arranged around the center line 9 , act with their tips facing the center line 9 on the sliver 10 , which is not represented in FIGS. 6 and 7.
FIG. 8 also shows a plate-shaped design of fiber guide elements 28 , wherein the edge of the fiber guide elements 28 facing the center line 9 extends in an arcuate shape toward the center, so that the sliver 10 , which is also not represented in FIG. 8, is guided and covered by the fiber guide elements over an area which is longer in comparison to FIG. 6 .
The fiber guide elements 29 represented in FIG. 9 are made of one piece, wherein a hollow body 30 has a sliver guide body 31 , as well as the fiber guide elements 29 , which are formed by cutting openings 32 . Cutting the openings 32 can take place in a simple manner by erosion or drilling, for example. The fiber guide elements 29 widen in the direction toward their free ends, which extend toward the axis of rotation of the hollow body 30 . In this way, the fiber guide elements 29 form and guide the sliver, not shown, moving along the axis of rotation of the hollow body 30 , in a particularly effective manner.
A sliver guide is shown in FIG. 10, whose fiber guide elements 33 are also a part of a single hollow body 34 , corresponding to the embodiment represented in FIG. 9 . The partially conically embodied hollow body 34 comprises a sliver guide body 35 with a sliver passage 36 , as well as fiber guide elements 33 , which are arranged concentrically around the axis of rotation 37 of the hollow body 34 and whose free ends extend toward the axis of rotation 37 . The sliver guide represented in FIG. 10 is integrated into a spinning station which to a large extent corresponds to the embodiment of the spinning station 1 represented in FIG. 1 and already extensively described. The spinning station represented in FIG. 10 has a disk 38 , which maintains the sliver guide bodies 35 in a centered position.
The spinning device in FIG. 11 also corresponds to a large degree to the already described spinning devices in FIGS. 1 to 10 . However, the disk 39 holds an alternative embodiment of the sliver guide. The sliver guide body 40 surrounds a slit-shaped sliver passage 41 . The fiber guide elements 42 , 43 , which follow the sliver passage 41 in the direction of the fiber travel and constitute a unit with the sliver guide body 40 , are arranged on the lengthwise sides of the slit-shaped sliver passage 41 such that the fiber guide element 42 acts from above on the center of the passing sliver 44 , and the fiber guide element 43 , which lies opposite the fiber guide element 42 , acts on the center of the underside of the sliver 44 with a guiding effect, with the surface of the sliver 44 being partially covered. The inward facing surfaces of the fiber guide elements 42 , 43 , which respectively come into contact with the sliver 44 , extend inclined slightly obliquely inwardly relative to the fiber flow direction and toward the center line 45 of the sliver 44 without reaching it. The surfaces of the portions of the fiber guide elements 42 , 43 , which directly adjoin the sliver guide body 40 and are inwardly oriented toward the sliver 44 , are spaced a slightly larger distance from the center line 45 in comparison to the surfaces of the fiber guide elements 42 , 43 located at the free ends 46 , 47 in the fiber flow direction, which makes sliver insertion easier and improves the guidance of the passing sliver 44 .
A further alternative embodiment can be understood from FIGS. 12 to 14 . These drawing figures show different plan views of a sliver guide body 48 with a sliver passage 49 , wherein the sliver guide body 48 , together with two fiber guide elements 50 , 51 , form a unit made in one piece. The surfaces of the fiber guide elements 50 , 52 , which respectively lie toward the imaginary center line 52 of the sliver, not represented, extend slightly obliquely toward the interior inclined toward the fiber flow direction and toward the center line 52 without reaching it, with the angle being approximately 89 degrees. The sliver passage is designed in the shape of a slit with a height 53 of, for example, about 0.6 mm and a width 54 of, for example, about 3.6 mm. During the operation of the spinning process, the cross section of the sliver passage 49 is filled by the passing sliver. At the rear end of the sliver guide body 48 , as viewed in the fiber flow direction, fiber guide elements 50 , 51 are centrally connected respectively at the upper and lower end edges of the longitudinal side of the slit-shaped sliver passage 49 . The ends 55 , 56 of the fiber guide elements 50 , 51 are embodied to be concave in the direction toward the center line 52 .
The invention is of course not limited to the represented exemplary embodiments. For example, besides the represented fixed embodiment, the spindle 13 can also be designed to be rotatable. The direction of turning of the spindle 13 and the discharge direction of the nozzles 21 cause the sheath direction of the fibers. For an undisturbed sheath direction of the sheath of fiber ends, the direction of turning of the spindle 13 and the discharge direction of the air nozzles 21 preferably coincide. The center line 9 of the sliver 10 need not lie continuously flush on the extension of the axis 8 of the spindle 13 , but in parts can for example extend at an acute angle in relation to the axis 8 .
The drive and the seating of device elements, as well as the control and linkage with upstream or downstream units, to the extent not described in detail herein, can be accomplished in a manner known per se.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto.
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A device for producing spun yarn by means of an airflow acting in the area between a sliver guide and a spindle ( 13 ) on fibers of a non-twisted sliver ( 10 ) drafted and delivered by a drafting arrangement in order to twist the fibers. Thereafter, the sliver ( 10 ) is passed through the spindle ( 13 ). Outside of an imaginary center line ( 9 ) of the traveling sliver ( 10 ), the sliver guide is arranged such that the fibers are passed along the inward lying surface of the sliver guide. The sliver guide comprises fiber guide elements ( 16 ) spaced apart from each other, which permit the free passage of a core fiber bundle. An improved spinning process, along with high productivity and increased yarn strength is possible by means of the device of the invention. The spinning device can be manufactured and operated cost-effectively.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/503,045, with a filing date of Jul. 27, 2011, which is expressly incorporated herein in its entirety by reference hereto.
FIELD OF THE INVENTION
[0002] The present invention relates generally to methods of constructing buildings for commercial and residential use, and in a particular though non-limiting embodiment, to a method of constructing buildings using a combination of standard construction materials and steel containers.
BACKGROUND OF THE INVENTION
[0003] There are many known methods in the art for constructing a building. Typically a building is constructed on-site, requiring many hours of skilled labor and using common construction supplies, such as brick, mortar, and lumber. Such supplies are often very costly. Furthermore, typical construction may not be strong or durable enough in certain areas of the country more prone to earthquakes, hurricanes, and other serious weather.
[0004] Recently, more cost-effective methods of construction have been proposed. One such method is to fabricate a building of steel in a factory and then move the building to the desired site. This method has proven to be faster and less expensive than traditional construction methods.
[0005] However, the metal used in such construction is very heavy and expensive to transport. Also, when using a traditional pre-fabricated metal building, there is a subsequent inability to expand the interior user space. Furthermore, steel buildings are frequently not as aesthetically pleasing, and do not have the look or feel of a traditionally constructed building. There is, therefore, a long-standing yet unmet need for methods of constructing homes in a stronger, economical and time-efficient manner, while still pleasing prospective owners aesthetically.
[0006] Turning for a moment to a seemingly unrelated issue, as more products are shipped to the U.S. from overseas, particularly Asia, ever greater numbers of metal shipping containers have begun stacking up in the major shipping ports. Consequently, it is oftentimes less expensive to buy new shipping containers in Asia than it is to ship the old containers back to the U.S. Moreover, the useful life of a standard shipping container is only about five (5) years. After that time, the containers just sit empty in abandoned shipyards.
[0007] A standard shipping container range from 19 feet to 55 feet long, 7 feet to 9 feet wide and 8 feet to 10 feet high. The containers are typically made of stronger steel than standard steel, known as Cor-ten steel, which does not rust or corrode. Furthermore, the steel is mold-resistant. The floor of a standard shipping container is made of hardwood and is constructed to withstand several tons of internal weight. The containers are built to withstand typhoons, tornadoes, hurricanes, and earthquakes.
[0008] Due to their durability, adaptability, light weight, low cost, and ease of stackability, new ideas for reusing the containers are currently being sought.
[0009] The shipping containers have been used in the past as storage units, temporary secure spaces at construction sites, and make-shift shelters. Furthermore, the containers have been used as small offices, workshops, or even employee quarters.
[0010] Therefore, there is also a long-standing yet unmet need to design methods of using the shipping containers in new and novel ways.
SUMMARY OF THE INVENTION
[0011] A building is provided, including at least two shipping containers, said containers comprising a top wall, a bottom wall, and two opposed side walls, said containers being mounted to a foundation in a spaced-apart, parallel manner, wherein portions of the adjacent inner side walls of said containers are removed, and further wherein a roof is attached to the top walls of said containers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
[0013] FIG. 1 is a schematic diagram showing side ( 1 A) and top views ( 1 B and 1 C) of a 10-story embodiment.
[0014] FIG. 2 is a schematic diagram showing a side view of a configuration according to an example embodiment, with the recessed-in option on either one side or both.
[0015] FIG. 3 is a schematic diagram showing a side view of a configuration according to an example embodiment, with the recessed-in option on either one side or both.
[0016] FIG. 4 is a schematic diagram showing a side view of a configuration according to an example embodiment, with the recessed-out option on either one side or both.
[0017] FIG. 5 is a schematic diagram showing a side view of a configuration according to an example embodiment, with the recessed-out option on either one side or both.
[0018] FIG. 6 is a schematic diagram showing a side view of a configuration according to an example embodiment, raised with additional containers and the option of vertical containers.
[0019] FIG. 7 is a schematic diagram showing a side view of a configuration according to an example embodiment, with stacked and/or detached containers including an example roof configuration.
[0020] FIG. 8 is a schematic diagram showing a top view of a configuration according to an example embodiment, including attached or detached unit groups.
[0021] FIG. 9 illustrates the support detail according to example embodiments.
DETAILED DESCRIPTION
[0022] In an example embodiment of the present invention, metal shipping containers or other suitable metal containers are used in combination with traditional construction methods and materials in order to produce a hybrid-construction building. In example embodiments, the shipping container(s) serve as strong structural elements of the building. Unlike more traditional, all-metal pre-fabricated buildings, hybrid-construction buildings look and feel more like traditional buildings, yet still have the advantages of a pre-fabricated metal building, including faster construction, simplified labor, and reduced construction costs.
[0023] The cost of purchasing the shipping containers is less than that of traditional construction materials, such as bricks and mortar. Furthermore, using the containers as the structural element of a building requires a smaller and less expensive foundation than traditional materials.
[0024] In exemplary embodiments, the shipping containers are used as modular elements that can be combined and connected in a manner to form larger, stronger structural frames for a building.
[0025] The variety of examples embodied in FIGS. 1-9 is provided to illustrate a sample of arrangements. The examples of arrangements and configurations are not intended to limit the possibilities of interior or exterior configuration of containers or the use of interior spaces.
[0026] FIGS. 1-9 illustrate example embodiments of structures for residential use or light commercial spaces. According to example embodiments, the structures range from one to ten stories high, stacked either at a parallel or perpendicular to each other. Further examples are stacked at a 90 degree angle flush at the corners to form a square or rectangle configuration, with the option to move one side or both sides in or out, up to eight feet depending on the interior or exterior space desired.
[0027] Referring now to FIG. 1 , an example embodiment of a building 30 is provided. Containers 20 are set parallel to each other on raised support cubes or reinforced concrete slabs. Containers 10 are likewise parallel to each other and stacked on top of containers 20 , so that containers 20 and containers 10 are perpendicular to each other. The corners of containers 10 and corners of containers 20 are flush with each other. Next, another set of containers 20 are stacked on top of containers 10 in the same manner, and so on and so forth. As shown in FIG. 1A , example embodiments are 10 stories high.
[0028] As shown in FIG. 1B , containers 10 and containers 20 are the same size, thereby forming a square configuration. In a further example embodiment, containers 10 and containers 20 are different sizes, forming a rectangle configuration, as shown in FIG. 1C .
[0029] Turning to FIGS. 2 & 3 , a further example embodiment of a building 30 is provided. In FIG. 2 , the corners of containers 20 are, for some stories, flush with the corners of containers 10 , but depending on the need or desire for more or less space, the containers 20 and 10 are stacked in a manner such that the corners of containers 20 are recessed-in on either one side or both, up to 8 feet (see, e.g., stories 3, 5, and 6).
[0030] Turning to FIGS. 3 , 4 & 5 , a further example embodiment of a building 30 is provided. In this embodiment, the containers 20 are stacked on top of containers 10 so that additional space between containers 20 is provided. The corners of containers 20 and 10 are stacked in a manner on some stories such that the corners of containers 20 are recessed-out on either on one side or both, up to 8 feet (see, e.g., stories 1, 3, 7, and 9).
[0031] Turning now to FIG. 6 , additional containers 20 are provided at the bottom of the building 30 , stacked vertically, to gain open space or height below the building 30 .
[0032] Turning next to FIG. 7 , various roof 40 options are illustrated on various stacked and/or detached containers.
[0033] Turning now to FIG. 8 , an example embodiment for a multi-family dwelling and/or a light commercial complex is provided. Multiple buildings 30 may be joined with additional containers 50 .
[0034] The containers are mounted to a foundation in a spaced-apart, parallel manner, thereby forming the sides of one floor of the structure. In between the containers, the space is enclosed to form the rest of the interior space, using construction methods already known to those of skill in the art. Access between the containers and the enclosed space is provided via doors or other means cut into the containers.
[0035] The containers provide actual additional usable space. In order to further increase the usable space of the building, the steel containers need only be spaced further apart or closer together depending or desired space. A common roof is installed over the containers and the enclosed space. In further exemplary embodiments, doors and windows may be cut into either (or both) the steel containers or the enclosed space.
[0036] According to example embodiments, the structures range from one to ten stories high, stacked at a parallel and/or perpendicular and/or 90 degree angle flush at the corners to form a square and/or rectangle configuration with the option to move one side or both sides in or out up to eight feet depending on the interior or exterior space desired.
[0037] FIG. 9 illustrates example embodiments of support cubes and concrete slabs. The steel containers may be mounted on a raised platforms (support cubes), thereby rendering the completed structure ideal for water front construction. Typical concrete foundations will be installed to meet local code and have recessed areas for the container in an attempt to line-up the floor elevations, if desired.
[0038] In still further embodiments, the metal shipping containers with additional anchoring could serve as an emergency shelter in case of a serious storm or other inclement weather, such as earthquakes, tornadoes, and the like.
[0039] The foregoing specification is provided only for illustrative purposes, and is not intended to describe all possible aspects of the present invention. While the invention has herein been shown and described in detail with respect to several exemplary embodiments, those of ordinary skill in the art will appreciate that minor changes to the description, and various other modifications, omissions and additions may also be made without departing from the spirit or scope thereof.
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A building is provided, comprising at least two shipping containers, said containers comprising a top wall, a bottom wall, and two opposed side walls, said containers being mounted to a foundation in a spaced-apart, parallel manner, wherein portions of the adjacent inner side walls of said containers are removed, and further wherein a roof is attached to the top walls of said containers.
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BACKGROUND OF THE INVENTION
The present invention relates generally to semiconductor device packages, and more particularly to packages with a gel filled cavity.
For certain semiconductor device packages, such as those that include pressure-sensing dies, it is known to apply a pressure-sensitive gel material over the pressure-sensing die to protect the die while still allowing the die to sense the atmospheric pressure outside of the package.
In some package designs having one or more dies, the gel fills the entire bottom portion of the package housing and is intended to cover all of the dies as well as any bond wires used to connect the dies to one another and/or to package leads. Unfortunately, due to the mechanical properties of some gels and some housing materials, when the gel is dispensed into the cavity, the gel's meniscus behavior results in the top surface of the gel having a concave shape. The concavity of the gel can increase during staging and curing, where staging refers to the time period from the dispensing of the gel until the beginning of the curing process.
FIGS. 1(A) and 1(B) show simplified cross-sectional side views of a conventional partially assembled semiconductor device package 100 having two dies 102 and 104 mounted within a package housing 106 that is partially filled with gel 108 and having at least one interconnecting bond wire 110 . Other bond wires, if any, are not shown. FIG. 1(A) shows the package 100 just after the gel 108 has been dispensed, while FIG. 1(B) shows the package 100 after the gel 108 has been cured.
As shown in FIG. 1(A) , the uncured gel 108 has a slightly concave top surface, while the top surface of the cured gel 108 in FIG. 1(B) has greater concavity. This greater concavity can result from the uncured gel 108 creeping up the walls of the housing 106 due to capillary action and/or shrinkage of the gel 108 during the curing process.
Unfortunately, as represented in FIG. 1(B) , the increase in the concavity of the gel 108 can result in the exposure of portions of one or more of the bond wires 110 outside of the cured gel.
Furthermore, the concavity of the cured gel 108 in FIG. 1(B) corresponds to a relatively large variation in the thickness of the gel 108 across the width of the package 100 , with the gel 108 being thicker at the edges of the package and thinner at the middle of the package.
Conventional package qualification processes involve thermal cycling during which the fully assembled packages are repeatedly heated up and cooled down over the range of expected operating temperatures for the package. The varying gel thickness across the width of the package can result in relatively large internal stresses during thermal cycling that can cause permanent damage to the package, such as broken and/or disconnected bond wires. Accordingly, it would be advantageous to have an assembly process that ensures the bond wires are covered with gel.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and is not limited by the accompanying figures, in which like references indicate similar elements. Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the thicknesses of layers and regions may be exaggerated for clarity.
FIGS. 1(A) and 1(B) show simplified cross-sectional side views of a conventional partially assembled semiconductor device package having, respectively, uncured and cured gel material;
FIGS. 2 (A)-(C) show simplified cross-sectional side views of three different steps in the assembly of a semiconductor device package according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Detailed illustrative embodiments of the present invention are disclosed herein. However, specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments of the present invention. The present invention may be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein. Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments of the invention.
As used herein, the singular forms “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It further will be understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” specify the presence of stated features, steps, or components, but do not preclude the presence or addition of one or more other features, steps, or components. It also should be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
In one embodiment, the present invention provides a method of assembling a semiconductor device package. The method includes (a) dispensing uncured gel material into a cavity of a partially assembled semiconductor device package, where the package includes at least one die mounted within a package housing, and where the gel material has a top surface with a first shape; (b) applying a jig over the uncured gel material to change the top surface of the uncured gel material to have a second shape different from the first shape; (c) curing the uncured gel material with the applied jig; and (d) removing the jig such that the top surface of the cured gel material substantially retains the second shape.
In another embodiment, the present invention is a semiconductor device package assembled in accordance with the above-described method.
In yet another embodiment, the present invention provides a semiconductor device package comprising a package housing, at least one die mounted within the package housing, one or more bond wires connected to the at least one die, and cured gel material covering the at least one die and filling a bottom portion of the package housing, wherein a top surface of the cured gel material has a convex shape.
Referring now to FIGS. 2 (A)-(C), simplified cross-sectional side views of three different steps in the assembly of a semiconductor device package 200 are shown. The package 200 has two dies 202 and 204 mounted within a package housing 206 . In a preferred embodiment, at least one of the dies is a pressure sensor die. The housing 206 may comprise a multi-layer substrate or a pre-molded lead frame, having molded sidewalls formed thereon. The housing 206 is at least partially filled with a gel 208 that covers the dies 202 and 204 , or at least the pressure sensing die. The two dies 202 , 204 may be connected to each other and/or to a substrate bond pad with bond wires 210 , one of which is shown. It is preferred that the gel 208 also covers the bond wires 210 . FIG. 2(A) , which is analogous to FIG. 1(A) , shows the partially assembled package 200 just after the gel 208 has been dispensed into a cavity formed by the housing 206 , with a top surface of the gel 208 automatically assuming a concave shape.
As shown in FIG. 2(B) , before the gel 208 is cured, a jig (i.e., tool) 212 , having a bottom surface with a concave shape and lateral dimensions corresponding to the lateral dimensions of the housing cavity, is inserted into the package housing 206 and pressed into the gel 208 , such that the top surface of the gel assumes the shape of the bottom surface of the jig 212 . The gel 208 is then cured with the jig 212 in place. The jig 208 subsequently is removed after the curing process is complete (or at least after the gel 208 has solidified enough to retain the shape imposed by the jig 212 ).
Although not represented in the cross-sectional views of FIG. 2 , if the housing 206 has a cylindrical cavity, then the jig 212 will have a circular lateral shape that substantially matches the cylindrical cavity. Alternatively, if the housing 206 has a rectilinear cavity, then the jig 212 will have a rectangular lateral shape that substantially matches the rectilinear cavity.
FIG. 2(C) shows the package 200 after the gel 208 has been cured and the jig 212 has been removed. As shown in FIG. 2(C) , the top surface of the cured gel 208 has a convex shape that substantially matches the concave shape of the bottom surface of the jig 212 .
As a result of that convex shape, all of the bond wires 210 are completely covered by the cured gel 208 . Furthermore, as also a result of the convex shape and taking into account (e.g., subtracting) the thicknesses of the one or more dies 202 , 204 , the variation in the thickness of the gel 208 in FIG. 2(C) is less than the variation in the gel thickness in FIG. 1(B) . As such, the internal stresses during thermal cycling of the package 200 will be less than the internal stresses during thermal cycling on the corresponding, conventional package 100 , which stress reduction can reduce the incidence of permanent damage to the package 200 as compared to the package 100 .
Although FIG. 2 represents the assembly of a single semiconductor device package, in practice, one- or two-dimensional arrays of multiple packages are assembled simultaneously, typically as part of a single multi-package structure before they are separated into individual packages. In such cases, a multi-jig structure can be used having an array of jigs, each similar to jig 212 and coinciding with a corresponding package housing in the multi-package structure.
By now it should be appreciated that there has been provided an improved semiconductor device package and a method of forming the semiconductor device package. Circuit details are not disclosed because knowledge thereof is not required for a complete understanding of the invention.
Although the invention has been described using relative terms such as “upper,” “lower,” “front,” “back,” “top,” “bottom,” “over,” “under” and the like in the description and in the claims, such terms are used for descriptive purposes and not necessarily for describing permanent relative positions. It is understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.
Unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. Further, the use of introductory phrases such as “at least one” and “one or more” in the claims should not be construed to imply that the introduction of another claim element by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an.” The same holds true for the use of definite articles.
Although the invention is described herein with reference to specific embodiments, various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. Any benefits, advantages, or solutions to problems that are described herein with regard to specific embodiments are not intended to be construed as a critical, required, or essential feature or element of any or all the claims.
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A semiconductor device package is assembled using a jig that alters the shape of gel material disposed in a cavity in the package. In one embodiment, a jig having a concave bottom surface is inserted onto uncured gel material disposed within a cavity in a housing of the package to change a top surface of the gel from having a concave shape to a convex shape. The gel is then cured with the jig in place. When the jig is subsequently removed, the cured gel retains the convex shape, which helps to avoid any bond wires from being exposed. The re-shaped gel material reduces internal stresses during thermal cycling and can therefore reduce permanent damage to the package otherwise resulting from such thermal cycling.
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BACKGROUND OF THE INVENTION
This invention relates to automatic transmissions, such as motor vehicle transmissions, having three planetary gear sets.
While conventional automatic transmissions generally have three or four gear stages, the provision of additional gear stages can improve riding comfort and reduce fuel consumption. It can be assumed that, as the number of planetary gear stages is increased, the space requirement as well as the number of planetary gear sets or planetary gear elements and the number of shifting components, such as clutches and brakes, will increase sharply. In the development of modern multispeed automatic transmissions, one objective has therefore been to further increase the number of gear stages while, at the same time, keeping the space requirement and the number of shifting components as small as possible.
An automatic transmission that attempts to meet these requirements is described in the Korean periodical SAE, Vol. 1, 1991, page 285. The automatic transmission represented in FIG. 10 of that publication is designed as a six-stage transmission in which three planetary gear sets are arranged one after another in series and connected to each other to provide six forward speeds and one reverse speed using five shifting components, i.e., brakes or clutches.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved automatic transmission having planetary gear sets which overcomes the disadvantages of the prior art.
Another object of the invention is to provide an automatic transmission which is designed so that a group shift, that is, the actuation of two shifting components during one shift operation, can be avoided.
A further object of the invention is to provide a novel transmission arrangement having lower planetary gear speeds than prior art arrangements.
These and other objects of the invention are attained by providing an automatic transmission having three planetary gear sets arranged in series wherein the ring gear of the first planetary gear set is controlled by a brake, the planet gear support of the first gear set is connected to the ring gear support of the second gear set and to the sun gear of the third gear set and is also controlled by a brake, the planet gear support of the second gear set is connected to the planet gear support of the third gear set and is also controllable by a brake, and the ring gear of the third gear set is connected to an output shaft. With this arrangement, an automatic transmission is provided which is very short in structure and can be actuated without any group shift, containing only five shifting components and, moreover, exhibiting very favorable transmission and speed ratios.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the invention will be apparent from a reading of the following description in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic diagram illustrating a representative embodiment of an automatic transmission arranged according to the invention;
FIG. 2 is a schematic diagram illustrating another representative embodiment of the invention; and
FIG. 3 is a schematic diagram illustrating a modification of the embodiment shown in FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENTS
In the typical embodiment of the invention shown in FIG. 1, an engine M is arranged to drive a hydrodynamic torque converter W by way of a crankshaft 1. The turbine rotor of the converter W is connected to a transmission input shaft 2, on which two clutches K1 and K2 are mounted.
An automatic transmission to which the input shaft is connected has three planetary gear sets PS11, PS12 and PS13 arranged in sequence, each having a ring gear R11, R22 and R33, a planetary support P11, P22 and P33 for planet gears, and a sun gear S11, S22 and S33. Each of these three planetary gear sets is associated with a shifting component which, in this embodiment, takes the form of three brakes, B3, B2 and B1, respectively. The clutches K1 and K2 and the brakes B1-B3 of this transmission are electrohydraulically actuable in the usual manner.
In accordance with this embodiment of the invention, the sun gear S11 of the first planetary gear set PS11 is connected directly to the transmission input shaft 2, whereas the sun gear S22 of the second planetary gear set PS12 can be connected to the transmission input shaft 2 only by the clutch K1. The second clutch K2 permits connection of the planetary support P22 of the second planetary gear set PS12 to the transmission input shaft, and the planetary support P22 is in turn connected to the planetary support P33 of the third planetary gear set PS13.
Another feature of the transmission illustrated in FIG. 1 is that the planetary support P11 of the first planetary gear set PS11 is connected to the ring gear R22 of the second planetary gear set PS12, that ring gear also being coupled to the sun gear S33 of the third planetary gear set PS13 and being engagable by the brake B2 to hold it in a fixed position. Moreover, the planetary support P33 of the third planetary gear set P13, which is connected in fixed relation to the planetary support P22 of the second planetary gear set PS12, can be held in fixed position by the brake B1. Further, the ring gear R11 of the first planetary gear set PS11 can be stopped by the other brake B3. Finally, the ring gear R33 of the third planetary gear set PS13 is fixedly connected to an output pinion AR1 so as to drive the transmission output.
In the embodiment of the invention shown in FIG. 3, the transmission is similar to that of FIG. 1. The only difference is that the ring gear R33 is connected to an output pinion AR3 which is intermediate between the planetary gear sets PS32 and PS33. This configuration of an intermediate output is advantageous for some applications, but it does have the disadvantage that the brake B1 must be positioned after the third planetary gear set PS33, which increases the space required.
The transmissions illustrated in FIGS. 1 and 3 are provided with overdrives F1 and F3, respectively, by which the planetary gear supports P33 of the third planetary gear sets PS13 and PS33, together with the planetary supports P22 of the second planetary gear sets PS12 and PS32 are held fixed in one direction.
Table 1 below indicates which of the shifting components are activated in order to actuate each of the several gear stages of the transmissions shown in FIGS. 1 and 3. In this table, "X" indicates actuation of a shifting component, i.e., one of the clutches K1 and K2, the brakes B1-B3 and the overdrive F1 and F3, and "(X)" indicates actuation only in the engine-braking mode of operation. In addition, this table shows the step-up ratio i for each of the gear stages 1-6 and reverse.
TABLE 1______________________________________ Over- GearGear Brake drive Clutch RatioStage B1 B2 B3 F K1 K2 i______________________________________1 (X) X X 3.612 X X 1.93 X X 1.454 X X 1.05 X X 0.7446 X X 0.655R X X -5.51N --______________________________________
With this transmission arrangement, especially favorable speed ratios can be achieved for the planet gears of the three planetary gear sets. Thus, the ratio of planet gear speed to sun gear speed is 3.39 for the first planet gear set PS11, 2.22 for the second planet gear set PS12, and 1.17 for the third planet gear set PS13.
FIG. 2 illustrates a further embodiment according to the invention. As in the other embodiments, an engine M drives a hydrodynamic converter W by way of a crankshaft 1, the turbine rotor being connected to the transmission input shaft 2, and the transmission includes three planetary gear sets PS21, PS22 and PS23 arranged in sequence and connected to each other, each comprising a ring gear, a planetary support with planet gears and a sun gear.
For shifting the total of six forward gear stages and the one reverse stage, five shifting components K1, K2, B3, B2 and B1 are provided, each of which is electrohydraulically actuable. Similar to the transmissions shown in FIGS. 1 and 3, the clutches K1 and K2 are arranged on the transmission input shaft 2. In this arrangement, the sun gear S1 of the first planetary gear set PS21 is driven directly by the transmission input shaft 2, while the sun gear S3 is connectable to the transmission input shaft 2 by the clutch K1.
By actuation of the clutch K2, the planetary support P2 in the second planetary gear set PS22 is connectable to the transmission input shaft 2. This planetary support P2 is coupled to the ring gear R3 of the third planetary gear set PS23 and can also be held in fixed position by a brake B1.
Another feature of this transmission is that the planetary support P1 of the first planetary gear set PS21 is connected to the sun gear S2 of the second planetary gear set PS22 and can be held in fixed position by a brake B2. In addition, the ring gear R1 of the first planetary gear set PS21 can be held in fixed position by a brake B3.
Also, a ring gear R2 in the second planetary gear set PS22 is connected to the planetary support P3 of the third gear set PS23, the planetary support P3 being connected in driving relation to an output shaft AR2.
Finally, the planetary support P2 of the second planetary gear set PS22, which is coupled to the ring gear R3 of the third planetary gear set PS23, can be held fixed in one direction by an overdrive F2.
In contrast to the automatic transmissions shown in FIGS. 1 and 3, this transmission permits especially low planet gear speeds. For this transmission, Table 2 below indicates the shifting component engagements required for the six forward and one reverse gear stages, the "X" symbols marking activation of the shifting component, i.e., a brake, a clutch or the overdrive. Also, the transmission ratios i for the several gear stages are given.
TABLE 2______________________________________ Over- GearGear Brake drive Clutch RatioStage B1 B2 B3 F2 K1 K2 i______________________________________1 (X) X X 3.652 X X 1.9143 X X 1.4554 X X 1.0005 X X 0.7446 X X 0.655R X X -5.51N --______________________________________
As in the case of Table 1, activation of the brake B1 in the first speed is required only when the vehicle is being operated in the engine-braking (drag) mode of operation, represented by "(X)".
Similar to the transmission shown in FIG. 1, especially favorable speed ratios can be achieved with this transmission. Thus, the ratio of the planet gear speed to the drive speed, i.e., the sun gear speed, is 3.38 for the planet gears of the first gear set, 1.16 for those of the second gear set and 0.88 for those of the third gear set.
Although the invention has been described herein with reference to specific embodiments, many modifications and variations therein will readily occur to those skilled in the art. Accordingly, all such variations and modifications are included within the intended scope of the invention.
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A multispeed automatic transmission for motor vehicles has three planetary gear sets arranged in series, each having a ring gear, a planet gear support with planet gears, and a sun gear. Externally-controlled clutches and brakes are arranged to provide six forward and one reverse gear stages. To provide improved riding comfort and fuel economy, only five shifting components are required, and the construction of the transmission permits an especially short and economical structure and especially favorable planet gear speeds.
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This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. JP 2006-027072 filed Feb. 3, 2006, the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for reducing damage caused by one-ring scam phone calls to a communication terminal.
2. Description of the Related Art
In recent years, a caller ID function, which notifies a telephone number (a caller ID) of a calling side to a called side, has been provided in a common telephone. A called side telephone provided with the caller ID function displays a notified caller ID on a display, and stores the caller ID in a call registry. Accordingly, a user of the telephone is able to know who the calling side is on the basis of a displayed caller ID, without answering the phone. Also, a user is able to call back later using a telephone number stored in a call registry, if s/he cannot take a call.
Recently, however, there have been many cases of a caller ID function being abused by people who make one-ring scam phone calls (scammers), who most commonly target mobile phones. A one-ring scam phone call is an act of leaving a caller ID in a call registry of a called side and thereby leading a user of the called side to respond to an unintended pay-service.
Specifically, a scammer calls a mobile phone and hangs up immediately after one ring, thereby leaving the caller's telephone number in a call registry of the mobile phone, without being answered by a called side. If the user of the mobile phone calls back using the telephone number in the call registry, s/he is connected to an unintended pay-service. In the case of a mobile phone especially, the call back function is readily used as it is not only convenient but also necessary because a user may often not be able to answer a call, for example, while driving, or during a meeting. Therefore, mobile phone users would call back a telephone number stored in a call registry carelessly or unwittingly, and thereby become an easy target of one-ring scam phone calls.
Countermeasures to a one-ring scam phone call have been proposed by six Japanese unexamined patent publications: JP 2003-125066; JP 2004-048344; JP 2004-056324; JP 2004-120243; JP 2004-135124; and JP 2004-134903 which is to not store a caller ID of a phone call in a call registry that is not registered in a phonebook of a called mobile phone. This countermeasure is based on a belief that a call from a telephone not registered in a phonebook of a called mobile phone is likely to be a one-ring scam phone call, and by not storing a caller ID of such a call, a user would be prevented from calling back an unintended pay-service.
In contrast to the countermeasure, an aspect of the present invention proposes a method for preventing a one-ring scam phone call from being repeated. Specifically, an aspect of the present invention proposes a method of, when replying to, possibly a one-ring scam phone call, preventing a caller ID of a user from being notified to the scammer. This method is effective in preventing a one-ring scam phone call from being repeated, because if a caller ID is not notified to a scammer, s/he is not able to know for a fact whether a particular caller ID is actually being used.
Usually, a scammer causes a computer to generate caller IDs at random and dial the caller IDs without knowledge of whether the caller IDs are actually in use. However, once a scam-call is replied to with a user' caller ID attached, the scammer comes to know that the caller ID is in use and can repeatedly use the caller ID for scam phone calls. For this reason, preventing a scammer from knowing that a caller ID is in use can be a countermeasure to repeated one-ring scam phone calls.
The problem addressed by the present invention applies also to an email. As in the case of a phone call, a reply mail to a scammer with an email address attached may lead to a situation where a user is bombarded with unsolicited mails.
SUMMARY OF THE INVENTION
To address the above problem, an aspect of the present invention provides a communication terminal including a communication interface configured to exchange data via a communication network, a memory, a first table stored in the memory and configured to store identifiers of communication terminals which are senders of data received by the communication interface, a second table stored in the memory and configured to store identifiers of communication terminals designated by a user, a user interface configured to receive an input of an identifier of a communication terminal with which a communication is to be initiated, and a processor coupled with the communication interface, the memory, and the user interface, and configured to, determine whether the identifier of the communication terminal input via the user interface is stored in the first table, determine whether the input identifier of the communication terminal is stored in the second table, and if the input identifier of the communication terminal is stored in the first table and not stored in the second table, instruct the communication network not to notify an identifier of its own terminal to the communication terminal.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the present invention will be described in detail with reference to the following figures, wherein:
FIG. 1 is a block diagram illustrating a configuration of a communication system according to a first embodiment of the present invention;
FIG. 2 is a block diagram illustrating a configuration of a mobile phone according to the first embodiment;
FIG. 3 is a diagram illustrating contents of a phonebook stored in the mobile phone;
FIG. 4 is a diagram illustrating contents of a call registry stored in the mobile phone;
FIG. 5 is a diagram illustrating an architecture of the mobile phone;
FIG. 6 is a flowchart of an operation carried out by the mobile phone; and
FIG. 7 is a flowchart of an operation carried out by a mobile phone according to a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(1) First Embodiment
FIG. 1 is a block diagram illustrating a configuration of a communication system according to the present embodiment.
In the drawing, mobile phone network 100 may be a network of PDC (Personal Digital Cellular), GSM (Global System for Communications), or IMT-2000 (International Mobile Telecommunication-2000), and comprise plural base stations and switch centers. Each base station forms a wireless communication area, or cell, and communicates with mobile phones 10 - 1 to 10 - n located in the wireless communication area via a wireless channel assigned to the mobile phone.
Fixed-line phone network 200 may be a PSTN (Public Switched Telephone Network). The network is accessed by plural fixed-line phones 20 - 1 to 20 - n . The network is also accessed by mobile phone network 100 via a POI (Point of Interface) which is not shown.
Each of mobile phones 10 - 1 to 10 - n and fixed-line phones 20 - 1 to 20 - n have a telephone number assigned and communication can take place between a mobile phone and a fixed-line phone; between mobile phones; or between fixed-lined phones.
It should be noted that in the following description mobile phones 10 - 1 to 10 - n are each referred to as mobile phone 10 , and fixed-line phones 20 - 1 to 20 - n are each referred to as fixed-line phone 20 , except where it is necessary to specify otherwise.
FIG. 2 is a block diagram illustrating a configuration of mobile phone 10 .
As shown in the drawing, mobile phone 10 comprises: controller 11 ; wireless communication unit 12 ; speech processing unit 13 ; display 14 ; operation unit 15 ; and memory 16 . Controller 16 may be a CPU, and control components of mobile phone 10 . Wireless communication unit 12 comprises antenna 121 and a wireless communication circuit (not shown). Wireless communication unit 12 , when receiving a wireless signal from a base station of mobile communication network 100 , demodulates the signal by a frequency conversion or A/D conversion, and also makes an error correction on the signal. The resultant voice data is provided to speech processing unit 13 to be subject to a D/A conversion and amplification, and converted into sound in speaker 131 . The voice data is also provided to controller 11 . On the other hand, voice emitted by a user of mobile phone 10 is collected by microphone 132 and converted into a voice signal, and is further converted into digital data after amplification and an A/D conversion. The digital data is subject to an echo cancellation, and an error correcting code is attached to it, and further subject to a modulation and a frequency conversion. After that, the digital data is sent from antenna 121 to a base station as a wireless signal.
Display 14 comprises a liquid crystal display and a driving circuit for the liquid crystal display, and displays a variety of images such as a dialogue box. Operation unit 15 comprises a numeric keypad and keys such as an on-hook key and an off-hook key, and provides a signal to controller 11 according to an operation of a user.
Memory 16 may be an EEPROM (Electrically Erasable and Programmable Read Only Memory) or a flash memory, and stores computer programs, which are a series of actions executed by controller 11 in a particular order, and stores necessary data for the actions. Memory 16 has an area for storing a list of user identifiers of telephones (mobile phone 10 or fixed-line phone 20 ) and corresponding telephone numbers. Since the list is usually called a “phonebook”, the area for storing the list is referred to as “phonebook area”. FIG. 3 shows an example of contents stored in the phonebook area. The drawing shows that a telephone number “090-1111-1111” is assigned to a telephone of a user named “Taro Yamada”.
Memory 16 also has a call registry area where a telephone number included in a received call setup signal is registered with the received date and time. FIG. 4 shows an example of contents stored in the call registry area. FIG. 4 shows that a call is received from a telephone having a telephone number “03-9999-9999” on Oct. 1, 2005, 14:23.
Returning to the explanation of FIG. 2 , memory 16 also has a flag area where a flag, which indicates whether a caller ID function is enabled or disabled, is stored. If the value of a flag is “1”, or a flag is on, a caller ID function is enabled. On the other hand, if the value of a flag is “0”, or a flag is off, a caller ID function is disabled. A user can set a caller ID function by means of operation unit 15 , and the setting is stored in the flag area as a value of a flag.
If a caller ID function is enabled, controller 11 instructs, when a call is originated, via wireless communication unit 12 , mobile phone network 100 to notify a telephone number of mobile phone 10 to a called telephone. A switching center of mobile phone network 100 , according to the instruction, sends a call setup signal including the telephone number to the destination telephone. Consequently, the telephone number of mobile phone 10 is notified to the called telephone as a caller ID. On the other hand, if a caller ID function is disabled, controller 11 instructs, when a call is originated, via wireless communication unit 12 , mobile phone network 100 not to notify a telephone number of mobile phone 10 to a called telephone. A switching center of mobile phone network 100 , according to the instruction, sends a call setup signal not including the telephone number to the destination telephone. Consequently, the telephone number of mobile phone 10 is not notified to the called telephone.
Now, FIG. 5 is a diagram illustrating a configuration of hardware and software of mobile phone 10 hierarchically. As shown in the drawing, mobile phone 10 comprises, from the bottom layer to the upper layer, hardware HW; driver DR for controlling hardware HW; operating system OS for managing overall the functions of hardware HW such as input/output or storage; middleware MW that works on operating system OS and provides more specific functions than those of operating system OS; application program interface API that is a collection of instructions and functions; and application AP.
Now, an operation of mobile phone 10 will be described with reference to the diagram of FIG. 5 and a flowchart of FIG. 6 . An exemplary case described below is a case where mobile phone 10 - 1 calls fixed-line phone 20 - 1 using a caller ID of fixed-line phone 20 - 1 . In this case, it is assumed that mobile phone 10 - 1 has received a call from fixed-line phone 20 - 1 , and stores a caller ID of fixed-line phone 20 - 1 in a call registry. Also, contents of a phonebook and a call registry stored in memory 16 of mobile phone 10 - 1 are assumed to be those of FIGS. 3 and 4 . Further, a telephone number of mobile phone 10 - 1 is assumed to be “090-5555-5555”, and a telephone number of fixed-line phone 20 - 1 is assumed to be “03-9999-9999”.
A user of mobile phone 10 - 1 , by means of operation unit 15 , selects a telephone number and carries out an operation to call a telephone to which the telephone number is assigned. Specifically, the user selects a telephone number “03-9999-9999” registered in a call registry, and pushes an off-hook key of operation unit 15 , to make mobile phone 10 - 1 call a destination telephone. When receiving the instruction via operation unit 15 (step S 1 ; YES), controller 11 searches the call registry area of memory 16 for the telephone number “03-9999-9999” (step S 2 ), and determines whether the telephone number is stored in the call registry area (step S 3 ).
The operations of steps S 1 to S 3 correspond to an operation of arrow P 1 in FIG. 5 where application AP for originating a call sends an inquiry to hardware HW (memory 16 ) to confirm whether the telephone number “03-9999-9999” is registered in the call registry area, and an operation of arrow P 2 where hardware HW sends an ANSER to application AP. If the value of the ANSER is “1”, it means that the telephone number “03-9999-9999” is stored in the call registry area, and on the other hand, if the value is “0”, it means that the telephone number is not stored.
As a result of the determination of step S 3 , if the telephone number “03-9999-9999” is stored in the call registry area as shown in FIG. 4 (step S 3 ; YES), controller 11 proceeds to an operation of step S 4 . On the other hand, if the telephone number “03-9999-9999” is determined as not to be stored in the call registry area (step S 3 ; NO), controller 11 proceeds to a call origination (step S 8 ). This is because a telephone number not stored in the call registry area is unlikely to be a telephone number for a one-ring scam phone call.
At step S 4 , controller 11 searches a phonebook area of memory 16 for the telephone number “03-9999-9999”, and determines whether the telephone number is stored in the phonebook area (step S 5 ).
The operations of steps S 4 and S 5 correspond to an operation of arrow P 3 of FIG. 5 where application AP for originating a call sends an inquiry to hardware HW (memory 16 ) to confirm whether the telephone number “03-9999-9999” is stored in the phonebook area, and an operation of arrow P 4 where hardware HW sends an ANSER to application AP. If the value of the ANSER is “1”, it means that the telephone number “03-9999-9999” is stored in the phonebook area, and on the other hand, if the value is “0”, it means that the telephone number is not stored.
As a result of the determination of step S 5 , if the telephone number “03-9999-9999” is not stored in the phonebook area as shown in FIG. 3 (step S 5 ; NO), controller 11 determines on the basis of a flag stored in a flag area of memory 16 whether a caller ID function is enabled (step S 6 ). If the flag stored in the flag area is on, controller 11 determines that a caller ID function is enabled (step S 6 ; YES). In this case, controller 11 changes the setting of the flag from on to off to disable a caller ID function (step S 7 ).
The operations of steps S 4 and S 5 correspond to an operation of arrow P 5 of FIG. 5 where application AP for originating a call instructs hardware HW (wireless communication unit 12 ) to disable a caller ID function, and an operation of arrow P 6 that hardware HW notifies application AP that a caller ID function has been disabled.
Subsequently, controller 11 proceeds to a call origination, and causes wireless communication unit 12 to send a call setup signal including the telephone number “03-9999-9999” to a base station (step S 8 ). When doing so, since a caller ID function is disabled, controller 11 instructs mobile phone network 100 not to notify a telephone number “090-5555-5555” of mobile phone 10 - 1 to the called telephone. A switching center of mobile phone network 100 , according to the instruction, does not include the telephone number of mobile phone 10 - 1 in a call setup signal for calling fixed-line phone 20 - 1 having the telephone number “03-9999-9999”. Accordingly, the telephone number of mobile phone 10 - 1 does not become known to a user of fixed-line phone 20 - 1 .
As a result of the determination of step S 5 , if the telephone number “03-9999-9999” is stored in the phonebook area (step S 5 ; YES), controller 11 proceeds to a call origination (step S 8 ). This is because a telephone number stored in the phonebook area is unlikely to be a telephone number for a one-ring scam phone call.
As a result of the determination of step S 6 , if a caller ID function is disabled (step S 6 ; NO), controller 11 proceeds to a call origination (step S 8 ). In this case, since a caller ID function is disabled, controller 11 instructs mobile phone network 100 not to notify a telephone number of mobile phone 10 - 1 to a called telephone. Accordingly, the telephone number of mobile phone 10 - 1 does not become known to a user of fixed-line phone 20 - 1 , as in the above case.
To reiterate, according to the present embodiment, if a telephone number designated by a user is stored in a call registry area, and not stored in a phonebook area, a controller of a mobile phone disables a caller ID function so that a telephone number of the mobile phone is not to be notified to a called telephone. Accordingly, the user can avoid a situation where his/her mobile phone gets repeated one-ring scam phone calls.
(2) Second Embodiment
The present embodiment is characterized by displaying a selection screen on display 14 where a user can select whether to disable a caller ID function, when a telephone number designated by a user is stored in a call registry area, and not stored in a phonebook area.
A configuration of the present embodiment is the same as that of the first embodiment which is shown in FIGS. 1 and 2 . Therefore, an explanation of the configuration will be omitted.
An operation of the present embodiment will be described with reference to FIG. 7 . FIG. 7 is a flowchart illustrating an operation carried out by controller 11 of mobile phone 10 - 1 according to the present embodiment. The flowchart of FIG. 7 is different from that of FIG. 6 in that steps S 9 and S 10 are inserted between steps S 6 and S 7 . Namely, in the present embodiment, if a caller ID function is determined as being enabled (step S 6 ; YES), a selection screen where a user can select whether to notify a caller ID to a destination displayed on display 14 by controller 11 (step S 9 ). If the user selects not to notify a caller ID, and this operation is received by controller 11 via operation unit 15 (step S 10 ; NO), controller 11 disables a caller ID function. As a result, at step S 8 , controller 11 instructs mobile phone network 100 not to notify a telephone number “090-5555-5555” of mobile phone 10 - 1 to a called telephone. Accordingly, the telephone number of mobile phone 10 - 1 does not become known to a user of fixed-line phone 20 - 1 .
On the other hand, if the user selects to notify a caller ID, and this operation is received by controller 11 via operation unit 15 (step S 10 ; YES), controller 11 instructs, when a call is originated, by means of wireless communication unit 12 , mobile phone network 100 to notify a telephone number of the mobile phone to a called telephone. A switching center of mobile phone network 100 , according to the instruction, sends a call setup signal including the telephone number of mobile phone 10 to the destination telephone. Consequently, the telephone number of mobile phone 10 is notified to the called telephone as a caller ID.
(3) Modifications
(3-1) Modification 1
As described in the section of Related Art, while a normal call lets a phone ring long enough for a user to answer the phone, a one-ring scam phone call terminates after only one ring. Given this fact, it is considered that it is possible to determine whether a call is a one-ring scam phone call on the basis of the duration of a ring.
Specifically, controller 11 of mobile phone 10 measures a time between the receipt of a call setup signal and the receipt of a call disconnection signal which are sent from a base station, and determines whether the measured time is shorter than a threshold time. If the measured time is shorter than the threshold time, and further, if a telephone number designated by a user is stored in a call registry area and not stored in a phonebook area, controller 11 determines the call as being a one-ring scam phone call, and disables a caller ID function.
(3-2) Modification 2
In the first and second embodiments, a PHS (Personal Handyphone System®), a PDA (Personal Digital Assistant), or a fixed-line phone may be used as mobile phone 10 . Mobile phone 10 may be any terminal as long as it has a number for calling such as a telephone number.
(3-3) Modification 3
In the first embodiment, in addition to a history of received calls, a history of placed calls may be considered to determine whether to enable a call ID function.
Specifically, controller 11 of mobile phone 10 determines whether a telephone number designated by a user is stored as a telephone number of a placed call, in addition to whether the telephone number is stored in a call registry area and a phonebook area. As a result, if the telephone number is stored as a telephone number of a placed call, even if the telephone number is stored in a call registry area and not stored in a phonebook area, controller 11 enables a caller ID function. By the configuration, even in a case where a telephone number is not registered in a phonebook (some users do not register telephone numbers in a phonebook and make a call using a telephone number recorded as a received call), a caller ID function can be used.
Alternatively, when a telephone number designated by a user is stored as a telephone number of a placed call, controller 11 may adhere to a default setting of the caller ID function, instead of forcibly disabling a caller ID function. Namely, if a caller ID function is enabled at the time of the determination, controller 11 decides to use a caller ID function, and if a caller ID function is disabled at the time of the determination, controller 11 decides not to use a caller ID function.
(3-4) Modification 4
A computer program executed by controller 11 in the first and second embodiments may be provided in a recording medium such as a magnetic tape, magnetic disk, floppy disk®, optical recording medium, optical magnetic recording medium, CD (Compact Disk), DVD (Digital Versatile Disk), or RAM. Alternatively, the computer program may be provided via a mobile phone network or the Internet.
(3-5) Modification 5
The present invention may be applied to not only a telephone, but also to an email terminal. When the invention is applied to an email terminal, the terminal may comprise the following units:
a) a communication unit which communicates with a communication network for email exchange; b) an email address list memory which stores email addresses of email terminals which can be connected to the communication network and identification names of users of the email terminals in association with each other; c) a received email history memory which stores email addresses of emails received by the communication unit from the communication network; d) an operation unit which receives an operation from a user of designating an email address and instructing the sending of an email to an email terminal having the email address; and e) a controller which if the designated email address is stored in the received email history memory, and not stored in the email address list memory, does not notify an email address of its own terminal to the email terminal having the email address.
A detailed operation of the email terminal is as follows.
A user of the email terminal creates an email addressed to a destination email terminal by means of an operation unit. When the operation by the user is received by a controller, the controller searches a received mail history area of a memory to determine whether an email address of the destination email terminal is stored in the received mail history area. As a result of the determination, if the email address is not stored in the received mail history area, the controller proceeds to an operation of sending the email. On the other hand, if the email address is stored in the received mail history area, the controller searches an email address list area (area for storing a list of email addresses and corresponding user names) of the memory to determine whether the email address is stored in the email address list area. As a result of the determination, if the email address is not stored in the email address list area, the controller fills a dummy email address in a source address field of the email. Alternatively, the controller may fill a blank in the source address field. After that, the controller sends the mail to the destination email terminal.
According to the email terminal, if an email address designated via an operation unit is stored in a received email history memory, and not stored in an email address list memory, an email address of the email terminal is not notified to a destination email terminal. Accordingly, if a user unwittingly replies to an unsolicited mail transmitted randomly, the user is protected from repeated transmission of unsolicited mails.
The present invention, which is explained in the foregoing description as two different devices of a mobile phone and an email terminal, may be expressed in broad terms as a communication terminal including:
a) a communication unit which communicates with a communication network; b) a first memory which stores identifiers of communication terminals connectable to the communication network and identification names of users of the communication terminals in association with each other; c) a second memory which stores identifiers of communication terminals which are sources of data received by the communication unit from the communication network; d) an operation unit which receives an operation from a user designating an identifier and instructing the initiation of a communication with a communication terminal having the identifier; and e) a controller which if the designated identifier is stored in the second memory, and not stored in the first memory, does not notify an identifier of its own terminal to the communication terminal having the designated identifier.
In the description, “a communication with a communication terminal” is a verbal communication between phones or an exchange of emails between email terminals.
Also, the present invention may be applied to a mobile phone which is connectable to a WWW server, and is capable of filling in a user agent field of the header of an HTTP (Hypertext Transfer Protocol) message, an identifier of hardware or software of the mobile phone, which is used by the WWW server to provide content to the mobile phone according to the performance of the hardware or software. When the present invention is applied to such a mobile phone, the mobile phone may comprise the following units:
a) a communication unit which communicates with a communication network for an HTTP message; b) a list memory which stores network addresses of servers connectable to the communication network and identification names of the servers in association with each other; d) an operation unit which receives an operation from a user of designating a network address and instructing the sending of an HTTP message to a server having the network address; and e) a controller which if the designated identifier is not stored in the list memory, does not notify an identifier of hardware or software of its own terminal to the server having the designated network address.
In the description, “network addresses of servers” are URLs (Uniform Resource Locators) or IP (Internet Protocol) addresses. A “list memory” is a memory storing a list of names of servers (or WWW sites) and corresponding URLs like “favorites”. An operation of “not notify[ing] an identifier of hardware or software of its own terminal to [a] server” is, specifically, an operation of filling a blank in a user agent field of the header of an HTTP message, or an operation of filling a dummy identifier in the user agent field.
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A communication terminal includes a communication interface configured to exchange data via a communication network, a memory, a first table stored in the memory and configured to store identifiers of communication terminals which are senders of received data, a second table stored in the memory and configured to store identifiers of communication terminals designated by a user, a user interface configured to receive an input of an identifier of a communication terminal with which a communication is to be initiated, and a processor configured to determine whether the identifier of the communication terminal input via the user interface is stored in the first table, determine whether the input identifier of the communication terminal is stored in the second table, and if a result of the determination is affirmative, instruct the communication network not to notify an identifier of its own terminal to the communication terminal.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. § 119(e) on U.S. Provisional Application No. 60/719,128 entitled L AST S TAGE S YNCHRONIZER S YSTEM , filed on Sep. 21, 2005, by Timothy A. Hall, the entire disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a pulse jitter reduction circuit which is employed as a last stage synchronizer for synchronizing a pulser circuit for a time-of-flight (TOF) mass spectrometer with the data acquisition circuits to improve the signal resolution of the spectrometer.
A TOF mass spectrometer relies upon precise timing between the high voltage acceleration pulse applied to the flight tube to accelerate ions along the flight tube and the subsequent detection of the time of arrival of the ions by the data acquisition system. The high voltage pulse employed for accelerating the ions, therefore, must be synchronized with the data acquisition timing, such that ions corresponding to particular elements can be accurately identified. The more precise the timing relationship of the respective signals, the more precise and higher the resolution of the mass spectrometer. With conventional pulse-trigger systems employed to provide the high voltage pulses to the flight tube, inherent uncertainty exists in the pulse initiation. This inherent fluctuation in the pulse initiation time is referred to as “jitter” and is a limiting factor of the resolution of a TOF mass spectrometer. Jitter as high as 100 pico seconds (ps) or higher is common and adversely affects the resolution of a mass spectrometer, particularly where samples having closely grouped elemental ions are involved.
Thus, there exists a need for an improved triggering circuit which eliminates or greatly reduces jitter existing in conventional triggering circuits.
SUMMARY OF THE INVENTION
A pulse jitter reduction circuit employs a low jitter system clock coupled to a pulse generator and an ultra low jitter flip-flop to generate substantially jitter-free trigger signals employed to generate high voltage pulses for the flight tube of a TOF mass spectrometer. By eliminating time fluctuations due to jitter in the triggering signal, the predictability of the arrival time of ions at the detector in a flight tube of a TOF mass spectrometer is greatly improved, thereby improving the resolution of the mass spectrometer.
These and other features, objects and advantages of the present invention will become apparent upon reading the following description thereof together with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS.
FIG. 1 is an electrical circuit in block form of a TOF mass spectrometer incorporating a low jitter pulse generator of the invention;
FIG. 2 is a waveform diagram of electrical signals in the circuit of FIG. 1 ; and
FIG. 3 is an electrical circuit in block form showing additional details of the circuit of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , a TOF mass spectrometer 10 incorporates the circuitry of the present invention and includes a flight tube 12 (shown schematically in FIG. 1 ) in which ions are grouped in an ionization chamber at one end. The ion chamber generates and holds ions for subsequent acceleration by applied high voltage pulses from high voltage pulser circuit 14 . The ions are accelerated down the flight tube to a detector 16 within the flight tube. The details of one TOF mass spectrometer which could benefit from the circuitry of the present invention is disclosed in U.S. Pat. No. 5,981,946 entitled T IME - OF -F LIGHT M ASS S PECTROMETER D ATA A CQUISITION S YSTEM , the disclosure of which is incorporated herein by reference. As used herein, the expression “ultra low jitter” means the initiation of a pulse with a certainty of less than about 6 pico seconds (6 ps). When used in connection with a circuit definition, it means a circuit capable of such a performance level.
The circuit for generating an ultra low jitter trigger pulse includes an ultra low jitter clock 20 coupled to a pulse generator 22 which can be of conventional design and incorporated into a field programmable gate array (FPGA) to provide raw trigger pulses 52 (shown in FIG. 2 ). The raw trigger pulses 52 from generator 22 are shown in FIG. 2 with the shaded area representing the uncertainty in the initialization and termination of the pulses. This represents “jitter” which can be 100 pico seconds (ps) or more in the typical 4 nano second (ns) pulses 52 . The raw trigger pulses 52 are frequency controlled by the clock pulses 50 and are applied to ultra low jitter flip-flop circuits 24 , 26 , and 28 . The resultant low jitter trigger pulse 54 from circuit 24 is applied to the high voltage pulser 14 of the TOF mass spectrometer 10 .
As illustrated by pulses 54 in FIG. 2 , the jitter present in the raw trigger pulses 52 has been substantially eliminated. The high voltage pulses 56 generated by circuit 14 in response to pulses 54 exhibit a slight but very reduced amount of jitter as represented by the shaded areas on the leading and trailing edge of the pulses. This jitter is estimated to be in the neighborhood of about 5.4 ps representing about a 95% reduction in the jitter existent in the raw trigger signal.
The pulser circuit 14 applies high voltage pulses 56 to the ion chamber to accelerate ions down the flight tube 12 to the detector 16 . The output of detector 16 is an analog signal 58 which is applied to a switched preamplifier 18 having an output coupled to the input of an analog-to-digital (A/D) converter 30 . The signals 59 from the A/D converter 30 are synchronized with the high voltage pulses from pulser 14 by the ultra low jitter clock signals 50 from clock 20 .
Pulses identical to the raw trigger pulses 52 shown in FIG. 2 are applied to two additional ultra low jitter flip-flops 26 and 28 , which are employed for providing a test signal to the system for detecting the accuracy of the application of the low jitter pulses 54 , which is outputted separately from circuits 24 , 26 , and 28 . One of the test trigger pulses 54 is applied to a measuring instrument, such as an oscilloscope 27 , while another test pulse 54 from circuit 28 is applied to the switched preamplifier, which can be switched from looking at the signal from detector 16 and coupling them to the A/D circuit 30 or to transmit signals from circuit 28 to circuit 30 for calibrating the system.
The pulse generator, including the FPGA 22 , is coupled to an external PC 40 , which is conventionally programmed to receive data from the A/D converter 30 and FPGA 22 representing the ions detected by detector 16 . In addition, however, the FPGA controls the preamplifier 18 to look at either the signals from detector 16 or from the test pulse output from circuit 28 . By employing a test signal, the data acquisition system can be calibrated to great precision to assure the detected ions are accurately identified with their elements. The signals from the circuit shown in FIG. 1 are shown in FIG. 2 , with the clock pulses 50 having a frequency of from about 250 MHz to about 1.5 GHz in a typical TOF embodiment. In a preferred embodiment, the pulse frequency employed was 375 MHz. The trigger pulses 52 have a delay from the clocked pulses of about 500 ps due to the generation delay in the pulse-generating circuit 22 .
The subsequent low jitter trigger 54 from the ultra low jitter flip-flops 24 , 26 , and 28 are substantially jitter-free, as shown in FIG. 2 . The high voltage pulse 56 from high voltage pulser 14 is delayed approximately 1000 ps due to the inherent delay in a high voltage pulser circuit.
The data output signal from preamplifier 18 is shown by analog waveform diagrams 58 in FIG. 2 in which amplitude of the signal indicates the quantity of ions of a particular element have been detected. Finally, the output from A/D converter 30 is schematically illustrated by waveform 59 in FIG. 2 and comprises a digital number representing the number of and the timing of arrival of ions at detector 16 for two sampled ions (as an example). These signals are applied to the FPGA 22 , which outputs them as data to the input of the PC 40 , as shown by connection 21 .
The PC 40 is programmed as in prior Leco Corporation TOF mass spectrometers, such as Leco Model No. Pegasus® IV, to receive the data and provide an output to a printer and/or monitor for analytical samples under test. The PC 40 also applies control signals via conductor 23 to the FPGA 22 for initiating the test pulses and calibrating the instrument. The details of one embodiment of the ultra low jitter pulse generator is shown in FIG. 3 .
In FIG. 3 , the external PC 40 is shown coupled to the FPGA pulse generator 22 . In the preferred embodiment of the invention, the FPGA employed was a Virtex IV Series, Model No. XC4VLX100-12FF151 3C, available from Xilinx Inc. and which is driven by the ultra low jitter clock 20 . Clock 20 is a Model No. SAN K-A2907-500 available from Nel Frequency Controls Inc. and provides clock pulses to a clock driver circuit 25 comprising a Motorola MC100LVEP14, which applies the clock signals to the FPGA 22 . The same clock signals are applied to the D input of the ultra low jitter D-type flip-flop 24 . In one preferred embodiment of the invention, flip-flop 24 and flip-flops 26 and 28 were Model No. NB4L52 from Semi-Conductor Components Industries.
The ultra low jitter trigger pulses from the Q output of circuit 24 , represented by signals 54 in FIG. 2 , are applied to a signal level converting circuit 29 for converting the signal to a low voltage TTL signal, with circuit 29 comprising a Model No. MC100EPT21 circuit, whose output signals are coupled to a second level converting circuit 31 , which converts the low voltage TTL signals to a higher TTL level signal and comprises a Model No. 74ACT11244 circuit having output signals comprising the input to the high voltage pulser circuit 14 . Pulser circuit 14 comprises a Model 666-561 circuit available from Leco Corporation of St. Joseph, Mich.
The FPGA 22 is programmed via an external computer, such as PC 40 , to generate a repetitive raw trigger signal 52 ( FIG. 2 ) at a typical frequency of from about 500 Hz to about 100 KHz. The FPGA and the ultra low jitter flip-flop 24 are coupled to receive clock pulses 50 ( FIG. 2 ) from the output of the ultra low jitter system clock 20 , as seen in FIG. 1 . The signal 52 from FPGA is applied to the input of flip-flop 24 that has excellent jitter characteristics. The shaded areas on the leading and trailing edges of the raw trigger signal 52 represents the typical uncertainty in the pulse trigger initiation and termination and can vary up to 100 ps or more in a conventional pulse trigger circuit. This can lead to the problem discussed above,. namely, the loss of resolution for the TOF mass spectrometer. By controlling the jitter on the high voltage pulse 56 employing the circuit of the present invention, the uncertainty of the arrival time of accelerated ions to the detector 16 at the end of the flight tube 12 is reduced, thus increasing the resolution of the mass spectrometer.
It will become apparent to those skilled in the art that various modifications to the preferred embodiment of the invention as described herein can be made without departing from the spirit or scope of the invention as defined by the appended claims.
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A pulse jitter reduction circuit employs a low jitter system clock coupled to synchronize a pulse generating device and an ultra low jitter flip-flop to generate substantially jitter-free trigger signals employed to generate high voltage pulses for a flight tube of a time-of-flight mass spectrometer. By eliminating time fluctuations due to jitter in the triggering signal, the predictability of the arrival time of ions along a flight tube of a time-of-flight mass spectrometer is greatly improved, thereby improving the resolution of the mass spectrometer.
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FIELD OF THE INVENTION
[0001] The invention relates generally to improvements in apparatus for reducing cross-contamination, and more particularly to a re-use prevention mechanism and to a laryngoscope.
[0002] While the invention has been developed primarily for use in laryngoscopes, and will be described hereinafter with reference to this application, it will be appreciated that the invention is not limited to this particular application and may also be used, for example, in other medical instruments, such as endoscopes and catheters, or indeed, in non-medical applications where hygiene is important, for example in electric toothbrushes with disposable heads, to reduce the incidence of cross-infection or contamination resulting from re-use of disposable parts.
BACKGROUND OF THE INVENTION
[0003] Known laryngoscopes comprise an elongate handle and an arcuate blade that is adapted for insertion into a patient's throat. The blade is connected to the handle by rotating the blade upwardly with respect to the handle. The handle is hollow and contains batteries for powering a light source to provide illumination to a distal end of the blade.
[0004] Historically, the handle and blade have been formed from metal to provide the stiffness required for opening a patient's airway. Accordingly, these known laryngoscopes have a high capital cost, and are therefore sterilised and reused many times during their service life. The typical cleaning method is autoclaving, which is in itself expensive.
[0005] In recent years, concern has been raised as to the adequacy of the cleaning and sterilisation of laryngoscopes. It is noted that metal laryngoscope handles are particularly difficult to clean, as they are often knurled, which provides a multitude of locations for bacteria and other contaminants to avoid sterilisation. In an attempt to address this problem, some disposable blade laryngoscopes have been developed. However, known disposable blade laryngoscopes have retained the same connection system as for the older fully reusable metal laryngoscopes, in that the blade is rotated upwardly with respect to the handle to engage the blade to the handle. When the disposable blades are connected to the handle in this manner, the blade tip often touches the handle, and accordingly, contaminants present on the handle can be transferred to the blade and subsequently to the patient.
[0006] Another problem with known disposable blades is that they often lack means for preventing their accidental re-use. Where means for preventing blade re-use are provided, it is often only apparent after a user has attempted several times to connect the blade to the handle that the blade in hand is a used blade, thereby causing user frustration and time delays. As will be appreciated, such frustration and delays can be critical in many instances where laryngoscopes are required.
OBJECT OF THE INVENTION
[0007] It is an object of the present invention to overcome or substantially ameliorate one or more of the abovementioned disadvantages of the prior art, or at least to provide a useful alternative.
SUMMARY OF THE INVENTION
[0008] Accordingly, in a first aspect, the present invention provides a re-use prevention mechanism for an apparatus having a reusable part and a single-use disposable part connectable to the reusable part, the re-use prevention mechanism comprising:
[0009] a blocking portion disposed, in use, between the disposable part and the reusable part;
[0010] an actuating member operable between blocking portion and one of the disposable part and the reusable part for moving the blocking portion into a blocking position upon disconnection of the disposable part from the reusable part;
[0011] wherein, in the blocking position, the blocking portion engages an abutment surface on one of the disposable part and the reusable part if a user attempts to reconnect the disposable part to the reusable part and thereby prevents re-connection of the disposable part to the reusable part.
[0012] In a second aspect, the invention provides medical device comprising:
[0013] a reusable part defining a longitudinal axis;
[0014] a disposable part for connection to the reusable part by engaging the disposable part with a longitudinal end of the reusable part and rotating the disposable part relative to the reusable part about the longitudinal axis.
[0015] Preferably, the medical device further includes a re-use prevention comprising:
[0016] a blocking portion disposed, in use, between the disposable part and the reusable part;
[0017] an actuating member operable between blocking portion and one of the disposable part and the reusable part for moving the blocking portion into a blocking position upon disconnection of the disposable part from the reusable part;
[0018] wherein, in the blocking position, the blocking portion engages an abutment surface on one of the disposable part and the reusable part if a user attempts to reconnect the disposable part to the reusable part and thereby prevents re-connection of the disposable part to the reusable part.
[0019] Preferably, according to either of the above aspects, the actuating member is operable between the blocking member and the disposable part. More preferably, the actuating member resiliently biases the blocking portion toward the blocking position upon disconnection of the disposable part from the reusable part.
[0020] In a preferred form, when the disposable part is engaged with the distal end of the reusable part, the blocking portion engages a recess in the reusable part to rotationally lock the disposable part to the reusable part.
[0021] Preferably, the reusable part is elongate and defines a longitudinal axis. More preferably, the actuating member resiliently biases the blocking portion rotationally, about the longitudinal axis, toward the blocking position upon disconnection of the disposable part from the reusable part.
[0022] Preferably, the disposable part is adapted for connection to the reusable part by engaging the disposable part with a longitudinal end of the reusable part and rotating the disposable part relative to the reusable part about the longitudinal axis. More preferably, the reusable part is generally cylindrical and includes a pair of locking lugs extending radially outwardly from diametrically opposite sides thereof. In a preferred form, the disposable part includes a generally cylindrical tubular coupling sleeve that is adapted to longitudinally slidably engage over a distal end of the reusable part. The disposable part preferably includes a pair of locking flanges extending radially inwardly from diametrically opposite sides of the sleeve and adapted to engage the locking lugs upon rotation, about the longitudinal axis, of the disposable part relative to the reusable part.
[0023] Preferably, engagement of the blocking portion with the abutment surface limits the extent of longitudinal engagement of the disposable part with the reusable part to prevent engagement of the locking lugs and locking flanges. More preferably, a longitudinally extending recess is provided in said one of the disposable part and the reusable part, the blocking portion being engageable with the recess to permit sufficient longitudinal engagement of the disposable part with the reusable part to allow the locking lugs and locking flanges to engage.
[0024] In a preferred form, the disposable part includes a cylindrical coupling sleeve adapted to engage the reusable part. Preferably, the re-use prevention mechanism is, in use, located in the cylindrical coupling sleeve.
[0025] Preferably, the re-use prevention mechanism includes first and second interengageable collars connectable with one of the disposable part and the reusable part, the collars being rotatably lockable to one another in first and second relative rotational positions, wherein the blocking member extends from one of the collars, and wherein in the first position if a user attempts to connect the disposable part to the reusable part, the blocking portion engages the recess, and wherein in the second position if a user attempts to connect the disposable part to the reusable part, the blocking portion engages the abutment surface. In a preferred form, the collars are connected to the disposable part. More preferably, the blocking portion extends from the first collar.
[0026] Preferably, the second collar includes a locking pin for engagement with a corresponding locking aperture in the disposable part to prevent relative rotation of the first collar and the disposable part when the pin and aperture are engaged. The locking pin is preferably adapted to fail if a torque above a predetermined level is applied between the disposable part and the reusable part. Preferably, the locking pin is adapted to withstand a shear force of between around 5N and around 100N, more preferably, between around 30N and around 70N, and in a particularly preferred form, of around 45N.
[0027] Preferably, the actuating member takes the form of a resilient biasing finger extending longitudinally outwardly from the second collar, away from the reusable part, for engagement with an abutment portion on the disposable part to resiliently bias the second collar rotationally, about the longitudinal axis, with respect to the disposable part when the biasing finger is deformed against the abutment portion. The resilient biasing finger is preferably deformed against the abutment portion when the disposable part is rotated relative to the reusable part to disconnect the disposable part from the reusable part.
[0028] Preferably, the reuse prevention mechanism is captivity retained within the coupling sleeve of the disposable part. In a preferred form, the first collar includes a radially outwardly extending retaining lug engageable with a corresponding retaining groove in the disposable part for captivity retaining the reuse prevention mechanism within the coupling sleeve of the disposable part.
[0029] Preferably, the second collar includes at least one locking detent engageable with a corresponding notch in the first collar for locking the first and second collars against relative rotation about the longitudinal axis. More preferably, the locking detent engages the notch when the collars are in the second position. In a preferred form, the second collar includes three locking detents and the first collar includes three corresponding notches. Preferably, corresponding pairs of said detents and notches are unevenly circumferentially spaced about said re-use prevention mechanism.
[0030] Preferably, the collars permanently lock together when moved into the second position.
[0031] The second collar preferably includes a circumferential slot and the first collar preferably includes a corresponding radially extending guide projection engageable with the slot. More preferably, a first end of the slot defines the first position and a second end of the slot defines the second position. Preferably, a stop member is provided at the first end of the slot, the stop member being engageable by the guide projection to retain the collars in the first position. The guide projection is preferably disengageable from the stop member by applying a longitudinal compressive force between the disposable part and the reusable part to cause the guide projection to ride over the stop member.
[0032] A longitudinally extending opening preferably extends from one longitudinal end of the second collar and into the slot. Preferably, the guide projection is longitudinally slidably engageable with the longitudinal opening to facilitate interengagement of the first and second collars. In a preferred form, the second collar includes three slots and three corresponding longitudinal openings, and the first collar includes three corresponding guide projections. More preferably, the guide projections and longitudinal openings are unevenly circumferentially spaced about the re-use prevention mechanism, such that the first and second collars can only be interengaged in a single predetermined relative rotational orientation.
[0033] Preferably, with the collars in the first position, the disposable part can be axially slid onto the longitudinal end of the reusable part. More preferably, when the disposable part is engaged with the distal end of the reusable part and the disposable part is rotated relative to the reusable part in a predetermined direction, the collars are moved into the second position and the disposable part is locked to the reusable part in a configuration for use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] A preferred embodiment of the present invention will be described hereinafter, by way of an example only, with reference to the accompanying drawings, in which:
[0035] FIG. 1 is a schematic view of a laryngoscope system;
[0036] FIG. 2 a schematic view showing how the laryngoscope handle is mounted on the battery charging module;
[0037] FIG. 3 is a schematic view of the laryngoscope shown in FIG. 1 , wherein the laryngoscope blade and handle are connected for use;
[0038] FIG. 4 is a side elevation view of the laryngoscope handle of the system of FIG. 1 ;
[0039] FIG. 5 is an exploded side elevation view of the laryngoscope handle of FIG. 4 ;
[0040] FIG. 6 is an enlarged side elevation view of the distal end of the laryngoscope handle of FIG. 5 ;
[0041] FIG. 7 is a side elevation view of the laryngoscope blade of the system of FIG. 1 ;
[0042] FIG. 8 is an enlarged view of the proximal end of the laryngoscope blade of FIG. 7 ;
[0043] FIG. 9 is a partial side elevation view of the laryngoscope in a partly assembled state, with the coupling sleeve of the blade cut-away to show the re-use prevention mechanism in the first position;
[0044] FIG. 10 is a partial side elevation view of the laryngoscope, with the coupling sleeve of the blade cut-away to show the re-use prevention mechanism in a configuration for removal of the blade from the handle;
[0045] FIG. 11 is a longitudinal section view through the proximal end of the blade of FIG. 8 , shown with the re-use prevention mechanism of FIG. 10 installed in the first position;
[0046] FIG. 12 is a part sectional side elevation view of the assembled handle and blade of the laryngoscope of FIG. 3 , showing the re-use prevention mechanism in the second position;
[0047] FIG. 13 is an enlarged side elevation view of the re-use prevention mechanism of the laryngoscope system of FIG. 1 , shown with the first and second collars disengaged;
[0048] FIG. 14 is a side elevation view of the re-use prevention mechanism of FIG. 13 , shown with the first and second collars engaged in the first position;
[0049] FIG. 15 is a side elevation view of the re-use prevention mechanism of FIG. 13 , shown with the first and second collars engaged in the second position;
[0050] FIG. 16 is a longitudinal section view through the proximal end of the blade of FIG. 14 , taken after the blade has been removed from the handle and showing the blocking tab in a blocking position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Laryngoscope System
[0051] Referring to the drawings, and in particular to FIGS. 1 to 3 , there is provided a laryngoscope system 100 comprising a laryngoscope 110 including a reusable handle 120 and a single-use disposable blade 130 , as well as a battery charging module 150 .
Laryngoscope Handle
[0052] As shown in FIGS. 4 , 5 and 6 , the handle 120 is generally cylindrical and elongate to define a longitudinal axis 1201 , a proximal end 1202 and a distal end 1203 .
[0053] As can best be seen in FIG. 6 , the handle 120 is stepped radially inwardly near its distal end 1203 to define a circumferential annular abutment surface 1206 . A recess 1207 extends longitudinally from the abutment surface 1206 toward the proximal end 1202 of the handle 120 . The recess 1207 defines a gap in the abutment surface 1206 .
[0054] Referring again to FIGS. 4 and 5 , the peripheral surface of the handle 120 is provided with longitudinally extending contoured lands 1208 to increase surface friction. The smooth contouring of the lands 1208 allows for ease of cleaning of the handle 120 .
[0055] The handle 120 is hollow and includes an internal mounting frame 1209 to retain rechargeable batteries (not shown).
Laryngoscope Blade
[0056] As seen in FIG. 7 , the blade 130 is generally arcuate in shape for facilitating its insertion into the throat of a patient. A light pipe 1301 extends from a proximal end 1302 to a distal tip 1303 of the blade 130 for providing illumination into the patient's throat. The light pipe 1301 transmits illumination from a Light Emitting Diode (LED) (not shown) in the end of the handle 120 . A suitable light pipe 1301 is disclosed in the Applicants' earlier International Patent Publication No. WO2002/071930, the disclosure of which is incorporated herein in its entirety.
[0057] As best seen in FIG. 8 , a generally cylindrical tubular coupling sleeve 1304 is provided at the proximal end 1302 of the blade 130 to facilitate connection of the blade 130 to the handle 120 . The coupling sleeve 1304 is configured so as to be longitudinally slidably engageable over the distal end 1203 of the handle 120 . As shown in FIGS. 9 and 10 , a generally trapezoidal cut-out portion 1306 is provided in a wall of the coupling sleeve 1304 . The cut-out portion 1306 defines a radially extending abutment portion 1307 that is oriented diagonally with respect to the longitudinal axis 1201 . A longitudinally extending locking aperture 1308 is provided in the proximal end of the coupling sleeve 1304 , as can be seen in FIG. 11 .
Blade/Handle Coupling
[0058] Referring again to FIGS. 4 , 5 and 6 , the handle 120 includes a pair of locking lugs 1210 that extend radially outwardly from diametrically opposite sides of thereof. The blade 130 , as best seen in FIGS. 8 , 11 and 12 , includes a corresponding pair of locking flanges 1309 that extend radially inwardly from diametrically opposite sides of the to coupling sleeve 1304 for rotational engagement with the locking lugs 1210 . The locking flanges 1309 are adapted to engage the locking lugs 1210 upon rotation, about the longitudinal axis 1201 , of the blade 130 relative to the handle 120 in order to secure the blade 130 to the handle 120 against relative axial displacement, as shown in FIG. 12 .
Re-Use Prevention Mechanism
[0059] Returning to FIG. 11 , a re-use prevention mechanism 160 is captivity retained within the coupling sleeve 1304 of the blade 130 . When the laryngoscope 110 is in use, the re-use prevention mechanism 160 is located between the blade 130 and the handle 120 , as can be seen in FIG. 12 . The mechanism 160 includes first 1601 and second 1602 interengageable collars, which are shown in detail in FIGS. 13 to 15 . The collars 1601 and 1602 are rotatable relative to one another about the longitudinal axis 1201 between a first position, as shown in FIG. 14 , and a second position, as shown in FIG. 15 . The collars 1601 and 1602 are also rotatably lockable relative to one another in the first and second positions. Moreover, the collars 1601 and 1602 permanently lock together when in the second position.
[0060] Referring to FIG. 13 , the first collar 1601 includes a blocking portion in the form of a longitudinally extending generally rectangular tab 1603 . When the collars 1601 and 1602 are in the first position, as shown in FIGS. 9 , 11 and 14 , the blocking portion aligns with and engages the recess 1207 in the abutment surface 1206 . This engagement rotationally locks the first collar 1601 to the handle 120 , and thereby locks the blade 130 to the handle 120 if the first 1601 and second 1602 collars are rotationally interlocked in one of the first and second positions. Engagement of the blocking portion 1603 with the recess 1207 also permits sufficient longitudinal engagement of the blade 130 with the handle 120 to allow the locking lugs 1210 and locking flanges 1309 to engage, as shown in FIG. 12 . When in a blocking position, as shown in FIG. 16 , the tab 1603 is engageable with the abutment surface 1206 of the handle 120 to prevent the blade 130 from being reused by limiting the extent of longitudinal engagement of the blade 130 with the handle 120 and thereby preventing engagement of the locking lugs 1210 and locking flanges 1309 . As shown in FIG. 11 , a retaining lug 1604 also extends radially outwardly from a peripheral surface of the blocking tab 1603 for engagement with the retaining groove 1305 in the coupling sleeve 1304 of the blade 130 to captivity retain the reuse prevention mechanism 160 within the coupling sleeve 1304 .
[0061] Referring again to FIG. 13 , the second collar 1602 includes an actuating member in the form of a resilient biasing finger 1605 , which extends from the second collar 1601 longitudinally outwardly away from the handle 120 . As shown in FIG. 10 , the biasing finger 1605 is operable between the abutment portion 1307 of the blade 130 and the blocking tab 1603 for resiliently biasing the blocking tab 1603 rotationally about the longitudinal axis 1201 , so as to move the blocking tab 1603 into the blocking position, as shown in FIG. 16 , upon disconnection of the blade 130 from the handle 120 . When the blocking tab 1603 is in the blocking position, re-connection of the blade 130 to the handle 120 is prevented.
[0062] As can be seen in FIG. 13 , the second collar 1602 also includes a locking pin 1606 . As shown in FIGS. 11 and 12 , the locking pin 1606 is engageable with the locking aperture 1308 in the blade 130 to prevent relative rotation of the first collar 1601 and the blade 130 when the pin 1606 and aperture are engaged. The locking pin 1606 is adapted to fail if a predetermined torque is applied between the blade 130 and the handle 120 . The locking pin 1606 is designed to withstand a torque sufficient to apply a shear force to the pin of between around 5N and around 100N, and more preferably between around 30N and around 70N. However, in a particularly preferred embodiment, the pin 1606 is adapted to fail if a torque sufficient to generate a shear force of around 45N is applied.
[0063] Referring again to FIG. 13 , the second collar 1602 also includes three circumferentially spaced locking detents 1607 . The first collar 1601 includes three corresponding notches 1608 . The locking detents 1607 are engageable with the notches 1608 for locking the first 1601 and second 1602 collars against relative rotation about the longitudinal axis 1201 . The locking detents 1607 engage the notches 1608 when the collars 1601 and 1602 are in the second position, as shown in FIG. 15 . However, as shown in FIG. 14 , when not engaged with the notches 1608 , the locking detents 1607 resiliently engage a radially outwardly extending circumferential flange 1609 of the first collar 1601 and thereby resiliently bias the first 1601 and second collars 1602 longitudinally away from one another.
[0064] Again, referring to FIG. 13 , three circumferential slots 1610 are provided in the second collar 1602 and are engageable by corresponding guide projections 1611 extending radially outwardly from the first collar 1601 . The slots 1610 and guide projections 1611 , as with the detents 1607 and notches 1608 , are also unevenly circumferentially spaced. A first end 1612 of each of the slots 1610 defines the first relative position of the first 1601 and second 1602 collars, as shown in FIG. 14 , and a second end 1613 of the slots 1610 defines the second relative position of the collars 1601 and 1602 , as shown in FIG. 15 . A stop member 1614 is provided at the first end 1612 of each of the slots 1610 and is engageable by the corresponding guide projection 1611 to retain the collars 1601 and 1602 in the first position. The guide projections 1611 can be disengaged from the corresponding stop members 1614 by applying a longitudinal compressive force between the blade 130 and the handle 120 to cause the guide projections 1611 to ride over the stop members 1614 against the resilient bias of the locking detents 1607 .
[0065] As can be seen in FIG. 13 , three longitudinally extending openings 1616 extend from an inner longitudinal end 1616 of the second collar 1602 . Again, the openings 1616 are unevenly circumferentially spaced about the second collar 1602 . Each of the openings 1616 extends into a corresponding one of the three slots 1610 . The guide projections 1611 are each longitudinally slidably engageable with a corresponding one of the longitudinal openings 1616 to facilitate interengagement of the first 1601 and second 1602 collars. The uneven spacing of the openings 1616 and the guide projections 1611 about the second collar 1602 ensures that the first 1601 and second 1602 collars can only be interengaged in a single predetermined relative rotational orientation. It will be appreciated that this predetermined relative orientation corresponds to a predetermined relative rotational location of the blocking portion 1603 and the biasing finger 1605 .
Connection of the Blade and Handle
[0066] To install the re-use prevention 160 mechanism into the blade 130 , the first 1601 and second 1602 collars are connected together in the first position as shown in FIG. 14 . The re-use prevention mechanism 160 is then longitudinally inserted into the coupling sleeve 1304 of the blade 130 and is retained axially by engagement of the retaining lug 1604 and retaining groove 1304 and retained rotationally by engagement of the locking pin 1606 and locking aperture 1308 , as shown in FIG. 11 . When the collars 1601 and 1602 are in the first position and with the retaining lug 1604 and retaining groove 1304 engaged, the blocking portion 1603 is correctly aligned for engagement with the recess 1207 of the handle 120 . In a preferred form, the blade 130 is supplied with the re-use prevention mechanism 160 pre-installed, as shown in FIG. 11 .
[0067] To connect the blade 130 to the handle 120 , the distal end of the handle 120 is longitudinally inserted into the coupling sleeve 1304 and, if required, the handle 120 is rotated about the longitudinal axis 1201 until the recess 1207 aligns with the blocking tab 1603 . With the recess 1207 and blocking tab 1603 aligned, a longitudinal compressive force is applied between the blade 130 and the handle 120 to cause the blade 130 to be pressed fully on to the handle 120 , whereupon the blocking tab 1603 fully engages the recess 1207 and the guide projections 1611 are caused to ride over the corresponding stop members 1614 , and then the handle 120 is rotated anticlockwise with respect to the blade 130 to move the collars 1601 and 1602 into the second position, as shown in FIG. 12 . Engagement of the locking pin 1606 with the locking aperture 1308 and the blocking tab 1603 with the recess 1207 secure the first 1601 and second 1602 collars respectively to the blade 130 and handle 120 during rotation between the first and second positions.
[0068] During rotation of the blade 130 relative to the handle 120 between the first and second positions, the locking lugs 1210 and locking flanges 1309 engage to axially secure the blade 130 to the handle 120 in the second position, as shown in FIG. 12 . Also, when the second position is reached, the locking detents 1607 and notches 1608 engage to secure the first 1601 and second 1602 collars against relative rotation. Also, engagement of the guide projections 1611 with the slots 1610 locks the collars 1601 and 1602 together axially. Accordingly, in the second position, the collars 1601 and 1602 are permanently locked together. With the collars 1601 and 1602 so secured, engagement of the blocking tab 1603 with the recess 1207 and the locking pin 1606 with the locking aperture 1308 rotationally locks the blade 130 to the handle 120 .
[0069] It will be appreciated that during connection of the blade 130 to the handle 120 , the tip of the blade 130 is isolated from the handle 120 to reduce the probability of contamination of the blade 130 by the handle 120 . This situation is contrasted to that of known laryngoscopes, where it is necessary for the blade tip to be placed very close to the handle prior to align the coupling components of the blade and handle prior to rotating the blade upwardly with respect to the handle to lock the blade onto the handle.
Disconnection of the Blade and Handle
[0070] To disconnect the blade 130 from the handle 120 , the handle 120 is rotated clockwise with respect to the blade 130 , about the longitudinal axis 1201 . A predetermined torque must be applied between the blade 130 and the handle 120 to cause shear failure of the locking pin 1606 and thereby allow the handle 120 to rotate relative to the blade 130 . Once the pin 1606 has failed, the handle 120 will rotate sufficiently relative to the blade 130 to disengage the locking lugs 1210 and flanges 1309 . Also, as the handle 120 is rotated, the biasing finger 1605 is deformed against the abutment portion 1307 of the coupling sleeve 1304 , as shown in FIG. 10 , such that when the distal end 1203 of the handle 120 is longitudinally removed from the coupling sleeve 1304 , the biasing finger 1605 resiliently rotates the blocking tab 1603 in an anti-clockwise direction relative to the blade 130 and into a blocking position as shown in FIG. 16 . As discussed above, with the blocking tab 1603 in the blocking position, if a user attempts to re-connect the blade 130 to the handle 120 , the blocking tab 1603 engages the annular abutment surface 1206 of the handle 120 to prevent the extent of longitudinal engagement of the handle 120 and blade 130 required to allow the locking lugs 1210 and flanges 1309 to engage.
Alternative Embodiments
[0071] It will be appreciated by those skilled in the art that the claimed invention may be embodied in many other forms. Some alternative embodiments are provided below by way of example only:
[0072] the re-use prevention mechanism may be connected to the handle, rather than to the blade;
[0073] the actuating member may be connected to the blade or the handle rather than to either of the collars and may engage the collars, rather than being connected to one of the collars and engaging the blade or the handle;
[0074] the biasing finger may act between the handle and the blocking portion, rather than between the blade and the blocking portion.
[0075] As will be appreciated, the several examples of alternative embodiments listed above are by no means exhaustive, and those skilled in the art will understand that many additional alternative embodiments of various components of the illustrated laryngoscope may be employed within the scope of the invention. Also, while the invention has been described with reference to a laryngoscope, it can also be used in other medical instruments, such as endoscopes and catheters, or indeed, in non-medical devices where hygiene is important, for example in electric toothbrushes with disposable heads, to reduce the incidence of cross-infection or contamination resulting from re-use of disposable parts.
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A re-use prevention mechanism ( 160 ) for an apparatus ( 110 ) having a reusable part ( 120 ) and a single-use disposable part ( 130 ) connectable to the reusable part ( 120 ) is disclosed. The re-use prevention mechanism ( 160 ) comprises a blocking portion ( 1603 ) disposed, in use, between the disposable part ( 130 ) and the reusable part ( 120 ). An actuating member ( 1605 ) is operable between the blocking portion ( 1603 ) and one of the disposable part ( 130 ) and the reusable part ( 120 ) for moving the blocking portion ( 1603 ) into a blocking position upon disconnection of the disposable part ( 130 ) from the reusable part ( 120 ). In the blocking position, the blocking portion ( 1603 ) engages an abutment surface ( 1206 ) on one of the disposable part ( 130 ) and the reusable part ( 120 ) if a user attempts to reconnect the disposable part ( 130 ) to the reusable part ( 120 ) and thereby prevents re-connection of the disposable part ( 130 ) to the reusable part ( 120 ).
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RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING GOVERNMENTALLY FUNDED WORK
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] The present invention relates to a safety timer for use with an infant bottle. More particularly, the present invention relates to a safety timer that can be installed onto a baby bottle and set for a select period of time to coincide with the exposure of the baby/infant formula within the bottle to an unrefrigerated environment.
[0004] The use of baby or infant formula has been hailed as one of the more important advancements in infant nutrition. Baby formula is typically a scientifically balanced food that is specially designed to assist in providing the essential nutrients, vitamins, amino acids and other dietary requirements that are needed by infants from the day of birth until they are transitioned to other foods. The formula may be prepared from powder with milk being added, or as is believed to be the more common practice, it is commercially prepared and supplied for use in containers that can be kept on the shelf until needed
[0005] The amount of formula that may be available in a prepared container, or that might be prepared by the parent from a mix, is usually more than the infant will need for one feeding, which is especially true when the infant is a newborn. Feedings are frequent, but many times will only consist of an ounce or two. The residual quantity of formula is still good for use and the usual recommendation is that upon refrigeration it may be kept for up to 48 hours before it should be discarded. This is an economic issue for parents since the cost of formula is significant and the budgets for many young parents is often stretched anyway.
[0006] Recommendations for the handling of warmed formula is very specific. Once the formula has been prepared for use and warmed up for feeding to the baby, it should never be stored away again for future use, even if that use is intended within the next 48 hours. The reason is in the use of the bottle by the baby which introduces enzymes and bacteria into the formula which can thereafter incubate or cause the nutrients to breakdown. Thus any attempt to reuse once-warmed and use baby formula is very risky with respect to the infant's health. Along with these recommendations is another one relating to the period of use allowed for a baby bottle filled with newly minted formula and readied for use. It is urged by those in the field of infant nutrition to use the contents of the baby bottle within one hour once it has been warmed and readied for use.
[0007] The time span of one hour may seem like an easily controlled factor when one is considering the use of the prepared formula, but as any young parent can attest, time has a way of getting away from a person when they are contending with a fussy infant, or other children, or trying to manage numerous other household functions while at the same time attending to ht feeding of their baby. Many times young parents in this situation will no longer be able to recall how long the formula has been in use and if the one hour time frame has been reached, or worse, if it has been exceeded. Obviously, parents who are confronting this situation will opt for the safe route and will discard the formula, even if it might in reality there might be plenty of useful time left. The problem is that without some method or way of definitively measuring the time left, the parent will not have any confidence in using the product. Given the cost of formula, this problem represents a significant economic potential; given the potential for harm to the infant, the use of “old” formula represents an even more serious problem for the parents and the baby.
[0008] The present invention seeks to solve the foregoing problems and to provide a device and a method for imparting more control over the feeding and nutritional management of infant. As will be discussed in more detail below, the benefits of the present invention will result in less confusion and a greater degree of control over the care of babies and infants.
SUMMARY OF THE INVENTION
[0009] A novel safety timer for use with infant formula comprises a band portion and a timer portion, where the band portion resiliently encircles a baby bottle and is retained thereon, and where the timer portion is installed onto the band portion and is operable by a user for setting a select period of time. The timer, having been set for a select period of time, will preferably disclose the amount of time remaining before the end of the period of time and in one embodiment, the timer may annunciate the end of select period of time.
[0010] The band portion of the present invention may also provide an identification tag that can be associated with the particular baby who is to receive the formula.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is an isometric view of a baby bottle with the present invention installed thereon, with the timer portion exposed to view.
[0012] FIG. 2 is an isometric view of the safety timer of the present invention with the timer portion exposed and with the identification tag shown.
[0013] FIG. 3 is a front view of the safety time of FIG. 2 .
[0014] FIG. 4 is a rear isometric view of the safety timer of FIG. 2 , showing the timer access in the closed condition.
[0015] FIG. 5 is a rear isometric view of the safety timer of FIG. 4 with the timer access shown in the open condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] A novel safety timer for use with baby bottles is disclosed herein in both the drawings and in the specification. In particular, a baby bottle 10 is shown with the nipple 12 , the cap 14 , the bottle portion 16 which includes the base 18 . Disposed about the bottle portion 16 is the safety timer 20 which includes the timer portion 22 and the band portion 24 .
[0017] Turning now to FIGS. 2 and 3 , more details of the safety timer 20 can be seen, including the timer switch 30 , the timer face 32 , and the identification tag 34 . The band portion 24 is comprised of the band front 36 , the leading end 38 , the trailing end 40 and with the front flexible fabric fastener 42 . More details of the safety timer 20 are shown in FIGS. 4 and 5 , with the band rear 50 , the timer access 52 , the timer access fastener 54 , the timer rear 56 and the rear flexible fabric fastener 58 .
[0018] In use, the safety timer 20 is applied to a bottle 10 to be used by a parent when preparing to feed their infant. As mentioned above, the introduction of formula into the bottle 10 , warming it and then presenting it to the infant starts the time running as to when the formula contained in the bottle 10 would need to be discarded. The purpose of the safety timer 20 is to facilitate in this process by providing a visual indication as to how much time is left for each bottle in use and in some cases it may provide an audible alarm as well to indicate when the one hour time limit has been met.
[0019] In order to use the safety timer 20 , it is initially found in the open condition as shown in FIGS. 2 through 5 , and the user may take the trailing end 40 of the band portion 24 and while holding it to the side of the bottle portion 16 the leading end 38 of the safety timer 20 is wrapped around the bottle portion 16 . The leading end 38 is secured to the trailing end 40 by attaching the rear flexible fabric fastener 58 to the front flexible fabric fastener 42 which are of the Velcro® type of closure devices. The snugness of the fit of the band 24 around the bottle portion 16 can be, adjusted by adjusting the attachment of the leading end 38 to the trailing end 40 . A metal snap could be used between the two ends instead although in order to affirmatively retain the safety timer 20 to the bottle portion 16 it may be required sometimes to have an elastic component embedded in the band portion 24 .
[0020] Once installed, the safety timer 20 can be activated when the bottle 10 (with the formula in it) is put into use. This period of use is associated with the factors relating to the recommended limitations on the viability of the formula once it has been prepared and presented for use. To activate, the user will turn the timer switch to the 60 minute or “GOOD” position as displayed on the timer face 32 . The timer face 32 is incremented so that the age of the prepared bottle 10 is preferentially shown in descending increments until the full 60 minutes runs and the timer switch 30 indicates the “BAD” position on the timer face 32 . Obviously the “BAD” indication means that the prepared bottle should not be used any further and the user will discard the contents. In the preferred embodiment, the safety timer 20 would include a green LED (light emitting diode) to provide another means of visual indication to show that the contents of the bottle 10 remained safe to use.
[0021] The safety timer 20 can be reused any number of times. An identification tag 34 is preferably included on the band 24 and can be used to identify the bottle 10 as belonging to a particular child, thus avoiding confusion, especially if there are other parents using safety timers 20 in the immediate area. The timer 22 can be strictly a mechanical timer that will accurately time out the 60 minute time frame merely by having the user twist the timer switch 30 from the “BAD” position to the “GOOD” position, and otherwise providing an indication of the remaining time allowed for the period of use. A clockwork type mechanism can be activated in this fashion and depending on the unit; it may terminate in an audible chime or other indication. In an alternate, embodiment, the timer 22 can be battery powered and will increment the 60 minute time frame using an electrical movement for this purpose. An audible alarm can then be provided that will remain on until the user is alerted and takes action to turn it off. In addition, this version would also allow for an LED indication light to activate when the time-out condition is reached. A red LED would be an indication that the bottle 10 is not to be used and may alert the user more easily than by checking the timer face 32 , and would obviate the need for an audible alarm which might not be desired when the parent is trying to put the infant to sleep. Access to the timer 22 is provided for by way of the timer access 52 which is a flap that covers the area in the band where the timer 22 is held. Access may be needed at times to completely replace the timer 22 , or to allow the band to be laundered, or to replace batteries if the timer 22 is battery powered. The timer access 52 can be opened as shown in FIG. 5 and the use of the flexible fabric fasteners 54 are shown as the method by which the timer access 52 is kept closed.
[0022] In other variations on the present invention, the band can be fabricated as a closed loop obviating the leading end 38 and the trailing end 40 . In this event it would be preferable to use an elastic type of material to form the band 24 so that it will be retained on the bottle portion 16 .
[0023] The foregoing represents illustrations as to how the present invention may be used. None of the foregoing is intended to limit the scope of the invention in anyway and other variations on the concept as taught herein may be varied or modified by one skilled in the art without departing from the spirit of the invention.
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A novel safety timer for use with a baby bottle or the like comprises a timer portion and a band portion, where the band portion is reversibly retained on a baby bottle and holds the timer portion in a position suitable for use. The timer portion provides an indication of the status of the period of use during which the prepared formula is still considered to be safe to offer to the infant. The safety timer of the present invention may also include an identification tag to ensure the association of the baby bottle with a particular infant.
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[0001] This application claims the benefit of the Korean Application No. P2004-35809 filed on May 20, 2004, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a washing machine, and more particularly, to a washing machine that can be easily assembled.
[0004] 2. Discussion of the Related Art
[0005] Generally, a washing machine is an apparatus to get laundry such as clothes clean by a chemical interaction of detergent and friction between the laundry and washing water. The washing machine performs washing, rinsing and squeezing.
[0006] The washing machine includes a drum disposed inside a cabinet forming the exterior of the washing machine and receiving laundry therein. The washing machine is generally classified into a drum type washing machine, an agitator type washing machine and a pulsator type washing machine.
[0007] The drum type washing machine includes a plurality of lifters protruded from an inner circumference of a drum rotatably installed with respect to a horizontal axis in parallel with a floor. The lifters lift and drop the laundry received in the drum while the drum rotates. At this time, the laundry is washed by the friction between generated water stream and the laundry.
[0008] Also, the agitator type washing machine performs washing by rotating a wing-shaped agitator protruded toward a center of a drum rotatably provided with respect to an axis normal to a floor in a left and right direction.
[0009] In addition, the pulsator type washing machine performs washing using water stream generated when a circular plate-shaped pulsator rotates.
[0010] Meanwhile, a control panel for displaying and controlling operation of the washing machine is disposed at an upper side of the cabinet and a decoration panel is coupled to the control panel in front of the control panel. The decoration panel improves the appearance of the washing machine and also prevents the control panel from being fractured or damaged due to an impact applied to the control panel.
[0011] However, in the related art washing machines, since the control panel is coupled with the decoration panel by a plurality of screws, it is problematic that the costs for manufacturing the washing machines increase and the assembling time increases. Also, the screws screwed in front of the decoration panel deteriorate the appearance of the washing machine.
SUMMARY OF THE INVENTION
[0012] Accordingly, the present invention is directed to a washing machine and method for assembling the same that substantially obviates one or more problems due to limitations and disadvantages of the related art.
[0013] An object of the present invention is to provide a washing machine having an easy coupling structure between a control panel and a decoration panel.
[0014] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0015] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a washing machine comprising: a console including at least one hole and provided at a predetermined portion of the washing machine; a control panel provided at a rear of the console, for controlling and displaying operation state of the washing machine; and a decoration panel including at least one protrusion provided at a rear surface of the decoration panel radiation and fixedly inserted into the hole of the console such that the decoration panel is coupled with a front surface of the console.
[0016] The protrusion inserted into the hole has one end bent and fixed. The decoration panel is made of metal material and the protrusion is formed integrally with the decoration panel.
[0017] The decoration panel has an opening formed at a center portion thereof and communicating with the control panel and an extending portion formed outside the opening and outwardly protruded. The protrusion is provided at an end of the extending portion. The console has a groove formed at a front thereof, through which the extending portion is inserted. The hole is formed inside the groove. Preferably, the washing machine further includes a sealing member disposed between the extending portion and the groove. The extending portion is continuously provided along a circumference of the opening.
[0018] Meanwhile, the decoration panel comprises: a first bent portion bent backward from an upper edge; a second bent portion bent downward from the first bent portion; and an upper fixing protrusion protruded downward from the second bent portion. The console has an upper fixing hole formed at an upper portion of the console and through which the upper fixing protrusion is inserted.
[0019] The protrusion has a length greater than a depth of the hole and also has a corner processed in a round shape.
[0020] According to another aspect of the present invention, there is provided a washing machine comprising: a console including at least one hole and at least one groove and provided at a predetermined portion of the washing machine; a control panel provided at a rear of the console, for controlling and displaying operation state of the washing machine; at least one extending portion protruded backward to be inserted into the groove; and a decoration panel including at least one protrusion provided at the extending portion such that an end of the protrusion is inserted into and fixed in the hole.
[0021] According to another aspect of the present invention, there is provided a method for manufacturing a washing machine, the method comprising the steps of: inserting an upper fixing protrusion formed at a decoration panel into an upper fixing hole formed at a console, and rotating the decoration panel by a predetermined angle to load the decoration panel into an upper surface of the console; inserting a protrusion formed at a rear surface of the decoration panel into a hole formed at the console; bending and fixing an end of the protrusion inserted into the hole; and assembling the console fixedly coupled with the decoration panel at a predetermined portion of the washing machine.
[0022] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
[0024] FIG. 1 is a perspective view of a washing machine according to the present invention;
[0025] FIG. 2 is a rear perspective view of a decoration panel according to the present invention; and
[0026] FIG. 3 is a front perspective view of a console into which a decoration panel of the present invention is assembled.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
[0028] An exemplary embodiment of a washing machine according to the present invention will now be described with reference to FIGS. 1 through 3 .
[0029] FIG. 1 is a perspective view of a washing machine according to the present invention.
[0030] Referring to FIG. 1 , the washing machine 1 includes a cabinet 2 , a tub 5 , a drum 4 , and a control panel 8 .
[0031] The cabinet 2 forms the exterior of the washing machine 1 and the tub 5 for receiving washing water is disposed inside the cabinet 2 . The drum 4 for receiving laundry is rotatably disposed inside the tub 5 . A driving motor (not shown) for providing the drum 4 with a rotational force is installed at an inner rear portion of the cabinet 2 .
[0032] The drum 4 has a plurality of perforated holes 6 through which the washing water received in the tub 5 passes. A drain hose 10 for draining washing water is disposed at a predetermined portion of the lower side of the cabinet 2 , and a feed hose 9 for feeding washing water is disposed at a predetermined portion of the rear of the cabinet 2 .
[0033] A top cover 7 is disposed at an upper side of the cabinet 2 . The top cover 7 includes an opening 11 for loading or unloading laundry, and a door 12 rotatably installed at an edge thereof, for opening and closing the opening 11 . Between the door 12 and the top cover 7 , a rubber packing for damping impact generated by opening and closing the door 12 and preventing leakage of washing water is preferably disposed. To effectively absorb the impact, it is preferable that the rubber packing is disposed at an edge of the opening 11 formed at the top cover 7 contacting the door 12 .
[0034] Meanwhile, the control panel 8 is disposed at a rear of the top cover 7 to display and control the operation of the washing machine. A console 13 where the control panel 8 is installed is disposed in front of the control panel 8 .
[0035] Hereinafter, the operation of the washing machine will be described.
[0036] First, a user opens the door 12 and loads detergent and laundry into the drum 4 through the opening 11 . After that, as the user manipulates the control panel 8 to operate the washing machine 1 , washing water is fed to the inside of the tub 5 through the feed hose 9 . The fed washing water is introduced into the inside of the drum 4 through the perforated holes of the drum 4 .
[0037] Thereafter, the driving motor operates to rotate the drum 4 clockwise and counterclockwise so that the laundry is rubbed with water stream to wash the laundry. After the washing of the laundry is completed, the washing water is drained to an outside of the washing machine 1 through the drain hose 10 .
[0038] FIG. 2 is a rear perspective view of a decoration panel according to the present invention and FIG. 3 is a front perspective view of a console into which a decoration panel of the present invention is assembled.
[0039] Referring to FIG. 2 , the decoration panel 14 includes a main panel 20 , a first bent portion 21 bent backward from an upper side of the main panel 20 , and a second bent portion 22 bent downward from an edge of the first bent portion 21 . The decoration panel 14 further includes at least one upper fixing protrusion 23 protruded from an end of the second bent portion 22 .
[0040] In addition, the decoration panel 14 includes a first extending portion 24 protruded backward along the edge of the decoration panel 14 . It is preferable that the first extending portion 24 is formed by bending the edge of the decoration panel 14 . At least one lower fixing protrusion 25 is formed below the first extending portion 24 .
[0041] Further, the decoration panel 14 includes an opening 14 a formed at a rear inner portion of the main panel 20 , a second extending portion 26 protruded backward formed in the edge of the opening 14 a , and at least one inner fixing protrusion 27 protruded backward along the second extending portion 26 .
[0042] Meanwhile, as shown in FIG. 3 , the control panel 8 is installed at a center portion of the console 13 . To prevent washing water from permeating into the control panel 8 , the decoration panel 14 is coupled with the console 13 at a front of the console 13 .
[0043] The console 13 includes a first groove 15 formed along an outer edge of the control panel 8 , through which the first extending portion 24 is inserted. At least one upper fixing hole 16 is formed at an upper portion of the first groove 15 , and at least one lower fixing hole 17 is formed at a lower portion of the first groove 15 .
[0044] Also, a second groove 18 is formed along an outer edge of the control panel 8 at an inner portion of the console 13 . The second groove 18 includes at least one coupling groove 19 .
[0045] The coupling between the console 13 and the decoration panel 14 will now be described.
[0046] Referring to FIGS. 2 and 3 , the first extending portion 24 and the second extending portion 26 formed at the rear surface of the decoration panel 14 are inserted and coupled with the first groove 15 and the second groove 18 . To prevent washing water from permeating into the rear surface of the decoration panel 14 , it is preferable that the first and second grooves 15 and 18 are continuously formed along the outer edge of the control panel 8 on the front of the console 13 . Similarly, the first and second extending portions 24 and 26 are continuously provided along an outer circumference of the opening formed at the decoration panel 14 . Also, it is preferable that a sealing member for preventing leakage of washing water is provided between the first and second extending portions 24 and 26 and the first and second grooves 15 and 18 .
[0047] The upper fixing protrusion 23 is inserted into the upper fixing hole 16 and the lower fixing protrusion 25 is inserted into the lower fixing hole 17 . Also, the inner fixing protrusion 27 is inserted into and fixed in the coupling hole 19 formed in the second groove 18 .
[0048] To couple the decoration panel 14 to the console 13 and at the same time fix the decoration panel 14 , it is preferable that the upper fixing hole 16 , the lower fixing hole 17 , and the coupling hole 19 are formed on the first groove 15 and the second groove 18 .
[0049] In addition, to protect the console 13 and the control panel 8 and improve the appearance, it is preferable that the decoration panel 14 is made of metal material.
[0050] Also, it is preferable that the lower fixing protrusion 25 and the inner fixing protrusion 27 are made thin or made of a material having ductility such that the lower fixing protrusion 25 and the inner fixing protrusion 27 are inserted into the corresponding lower fixing hole 17 and the corresponding coupling hole 19 and then bent by a predetermined angle.
[0051] It is preferable that one end of each of the lower fixing protrusion 25 and the inner fixing protrusion 27 should be protruded perforating the holes 17 and 19 . Accordingly, it is preferable that each of the lower fixing protrusion 25 and the upper fixing protrusion 27 has a length greater than a depth of each of the corresponding holes 17 and 19 .
[0052] Also, it is preferable that an end corner of each of the upper fixing protrusion 23 , the lower fixing protrusion 25 , and the inner fixing protrusion 27 is rounded to be easily inserted into the corresponding hole.
[0053] The procedure for coupling the decoration panel 14 to the console 13 will now be described with reference to FIGS. 2 and 3 .
[0054] First, the second bent portion 22 is inserted into the first groove 15 . At this time, the upper fixing protrusion 23 is inserted into the upper fixing hole 16 . Thereafter, the decoration panel 14 is rotated by a predetermined angle centering on the upper fixing protrusion 23 inserted into the upper fixing hole 16 , and is then loaded into the front surface of the console 13 .
[0055] Herein, the first extending portion 24 is inserted into the first groove 15 and the second extending portion 26 is inserted into the second groove 16 . The lower fixing protrusion 25 is inserted into the lower fixing hole 17 and the inner fixing protrusion 27 is inserted into the coupling hole 19 .
[0056] By doing so, the decoration panel 14 is loaded into the front surface of the console 13 . After that, an end of each of the lower fixing protrusion 25 and the inner fixing protrusion 27 protruded backward is bent by a predetermined angle. By doing so, the decoration panel 14 is stably fixed to the console 13 by the lower fixing protrusion 25 and inner fixing protrusion 27 .
[0057] For more effective fixing of the decoration panel 14 , it is possible to insert the upper fixing protrusion 23 into the console 13 to be protruded backward from the console 13 and bent the protruded end portion of the upper fixing protrusion 23 by a predetermined angle, thereby fixing the decoration panel 14 . At this time, it is preferable that the upper fixing protrusion 23 is made of a material having ductility such that the upper fixing protrusion 23 is inserted into the upper fixing hole 16 and is then bent.
[0058] Also, it is preferable that the length of the upper fixing protrusion 23 is greater than the depth of the corresponding upper fixing hole 16 such that one end of the upper fixing protrusion 23 perforates the upper fixing hole 16 and is protruded toward a backward direction of the console 13 .
[0059] Meanwhile, the console 13 into which the decoration panel 14 is assembled is coupled to an upper rear portion of the washing machine.
[0060] As described above, according to the washing machine of the present invention, since the decoration panel is coupled to the console without a separate fixing member such as a screw, the number of parts is reduced, thereby saving the manufacturing cost.
[0061] Also, since the protrusions formed in the decoration panel are inserted into the corresponding holes and then bent and fixed, it is possible to fix the decoration panel to the console easily. By doing so, the assembling time of the decoration panel and the console can be shortened.
[0062] In addition, since the portions fixing the decoration panel are not exposed to an outside, the appearance of the washing machine can be improved.
[0063] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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Provided is a washing machine including: a console including at least one hole and provided at a predetermined portion of the washing machine; a control panel provided at a rear of the console, for controlling and displaying operation state of the washing machine; and a decoration panel including at least one protrusion formed at a rear surface of the decoration panel radiation and fixedly inserted into the hole of the console such that the decoration panel is coupled with a front surface of the console.
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This is a continuation of patent application Ser. No. 08/825,949, filed on Mar. 31, 1997, now U.S. Pat. No. 5,831,914.
RELATED APPLICATION
This application is related to U.S. patent application Ser. No 08/825,948, entitled "Method of Making a Memory Fault-Tolerant Using a Variable Size Redundancy Replacement Configuration", now U.S. Pat. No. 5,831,913 herewith and being assigned to the same assignee of record.
FIELD OF THE INVENTION
This invention relates to a fault-tolerant memory, and more particularly, to a variable size redundancy configuration for replacing defective elements in a memory.
BACKGROUND OF THE INVENTION
CMOS technology has evolved such that the computer market has rapidly opened to a wide range of consumers. Today multimedia requires at least an 8MB and preferably even a 16 MB memory, which increases the relative cost of the memory system within a computer. In the near future, it is likely that 32 MB and 64 MB computers will become commonplace, which suggests a potential demand for 256 Mb DRAMs (Dynamic Random Access Memory) and beyond. Despite the huge array size and lithographic difficulties that ensue, it is more important than ever to increase the chip yield. Process engineers are constantly attempting to reduce and ultimately, eliminate or at the very least, mask defects. Faults that inevitably remain in the chip are generally overcome using special circuit designs, and more specifically redundancy replacement.
Conventional redundancy configurations typically revolve about a Fixed Size Redundancy Replacement (FSRR) architecture, wherein elements are grouped in units containing a fixed number of elements, which are used to replace defective elements within the memory device.
Various configurations within the FSRR architecture have been successfully implemented over the years. A typical FSRR configuration, which is commonly used for low density DRAMs is shown in FIG. 1a. Therein are depicted a fixed plurality of spares used for replacing defective elements within the memory and which are appended to each sub-array comprising the memory. Each redundancy unit (RU) is comprised of a plurality of redundancy elements (REs), (e.g., two RE per RU are illustrated therein), and which are used to repair existing faults (labeled X) within the corresponding sub-array. This scheme, labeled intra-block replacement, increases the redundancy area overhead as the number of sub-blocks increases for high density memories, since each sub-block requires its own, one or preferably two RUs. Thus, the efficiency of the RUs is rather poor in view of its inflexibility which reduces the chip yield substantially when faults are clustered in a given sub-array. The above mentioned concept is embodied in a configuration described in the article by T. Kirihata et al., entitled "A 14 ns 4 Mb DRAM with 300 mW Active Power", published in the IEEE Journal of Solid State Circuits, Vol. 27, pp. 1222-1228, September 1992.
Another FSRR redundancy replacement arrangement, known as a flexible redundancy replacement configuration is shown in FIG. 1b, wherein a memory is depicted having a single array of RUs to selectively replace failing elements anywhere in the memory. In this configuration, REs within the RU can repair faults (labeled X) located in any sub-array within the memory. The advantage of this arrangement over the previously described intra-block replacement is that one section, namely, a redundancy array, having a fixed number of RUs may advantageously be used to service any number of sub-arrays forming the memory. This translates into a substantial saving of real estate over the previous scheme, although it requires a substantial amount of additional control circuitry to properly service all the sub-arrays forming the memory.
There is yet another FSSR architecture, referred to block FSRR, and shown in FIG. 1c, wherein any number of faults (including all the faults) in a sub-array are replaced with a block redundancy. The size of the prior art block FSRR coincides with that of the sub-array, the sub-array being defined as a section of memory contained between sense amplifier strips. Since in this scheme, a defective block is replaced by a good block, it ensues that all defective REs contained within a block are simultaneously replaced by good REs. Although this replacement methodology introduces a new dimension in the repairability of defects, it also brings along a significant amount of added design space to accommodate the various configurations that make this architecture so desirable. Moreover, there is a significant drawback in that block redundancy cannot be used if the redundancy block itself has a fault, even if only one. Since, by definition, a block is large, the probability of finding at least one defect in the redundancy block is high. Although the subdivision of arrays depicted in FIG. lc is known in the art, no provisions exist to provide appropriate corrections when defects affect the block redundancy array.
More details regarding the above configurations and the various trade-offs may be found in an article by T. Kirihata et al., "A Fault-Tolerant Design for 256 Mb DRAMs", published in the Digest of Technical Papers of the 1995 Symposium on VLSI Circuits, pp. 107-108; in an article by T. Sugibayashi et al., "A 30 ns 256 Mb DRAM with Multi-divided Array Structure", published in the IEEE Journal of Solid State Circuits, vol. 28, pp. 1092-1098, November 1993; and in an article by H. L. Kalter et al., "A 50 ns 16 Mb DRAM with a 10 ns Data Rate and On-Chip ECC", published in the IEEE Journal of Solid State Circuits, vol. 25, pp. 1118-1128, October 1990.
In summary, a Fixed Size Redundancy Replacement (FSRR) arrangement consists of a fixed number of replacement units, each with the same number of REs to correct defects in the memory device. The flexibility of allocating a predetermined number of fixed-sized redundancy units allows the units and the control circuitry to be shared among the several memory sub-arrays, thereby significantly increasing the effective usage of the redundancy. This configuration has demonstrated its value by providing good repairability, specially of bit lines, (either single bits or multiple bits); wordlines, (either single words or multiple words), and the like, all falling under the category of "hard faults".
Yet, FSRR suffers from a distinct disadvantage in that it still requires a significant number of RUs (and corresponding control circuitry) to overcome another class of faults, labeled "retention faults", in which a bit, stored in the capacitor that forms a DRAM cell, fades away over time in a weak cell, thereby producing a fault. This problem is of utmost importance, particularly, since retention faults far exceed the number of hard faults.
Referring back to the hard faults within a memory, defects of this type tend to cluster, thereby ideally requiring a customized unit containing an equivalent number of redundancy elements. Hard faults are typically not too numerous, but their size can in itself be quite large, thereby necessitating multiple REs and/or large size REs to repair such faults. By way of example, if a sub-array contains four clustered defects, a 4-elements redundancy unit would be required to replace them. However, if five clustered defects were present, and only units containing four REs were available, the replacement of defects could potentially fail altogether in the intra-block replacement configuration (because not enough units would be available within the sub-array to service this number of faults). Similarly, a flexible replacement configuration also falls short since, in practice, only units of the "wrong size" are available to perform the repair, although flexible redundancy schemes are more likely to provide successful replacement than the intra-block replacement architecture.
Retention faults, on the other hand, occur randomly throughout the memory, and their number is typically high; yet, there is a distinct advantage in that they can be repaired with a single RE. In the intra-block replacement configuration, retention faults can only be serviced by RUs containing a fixed plurality of REs. Clearly, if RUs containing only one RE were designed with the intention of detecting randomly occurring retention faults, then such a configuration would be ideal for retention faults; yet they fall short for servicing hard faults (e.g, four units having one RE each would be needed to service a cluster of four hard faults). Retention faults are also difficult to repair even with a flexible redundancy replacement architecture because of the large number of such faults, which frequently may overwhelm the repair circuitry available in the memory device.
In view of the foregoing, the goal of an ideal redundancy configuration is to repair hard faults, retention faults, and block faults, whether randomly distributed throughout the memory or clustered therein, without introducing an onerous burden caused by a complex redundancy area overhead. Typically, this overhead is divided into: a redundancy element overhead and redundancy control circuitry overhead, both of which should be minimized to achieve good repairability and maintain optimum performance of the memory.
Related redundancy configurations, including some of the categories listed above, are described in the following references:
U.S. Pat. No. 5,491,664 to Phelan, issued Feb. 13, 1996, describes the implementation of a flexible redundancy memory block elements in a divided array architecture scheme. This configuration has both, the memory and the redundant memory blocks, coupled to a read bus to allow the redundancy memory in one memory sub-array to be shared by a second sub-array.
U.S. Pat. No. 5,475,648 to Fujiwara, issued Dec. 12, 1995, in which a memory having a redundancy configuration is described such that when an appropriate address signal agrees with the address of a defective cell, a spare cell provided by the redundant configuration is activated to replace the failing one.
U.S. Pat. No. 5,461,587 to Seung-Cheol Oh, issued Oct. 24, 1995, in which a row redundancy circuit is used in conjunction with two other spare row decoders, wherein by a judicious use of fuse boxes, signal generated by a row redundancy control circuit make it possible to replace failing rows with spare ones.
U.S. Pat. No. 5,459,690 to Rieger at al., issued Oct. 17, 1995, describes a memory with a redundant arrangement that, in the presence of normal wordlines servicing defective memory cells, enables faulty memory cells to be replaced with redundant cells.
U.S. Pat. No. 5,430,679 to Hiltebeitel et al., issued Jul. 4, 1995, describes a fuse download system for programming decoders for redundancy purposes. The fuse sets can be dynamically assigned to the redundant decoders, allowing a multi-dimensional assignment of faulty rows/column within the memory.
U.S. Pat. No. 5,295,101 to Stephens, Jr. et al., issued Mar. 15, 1994, describes a two level redundancy arrangement for replacing faulty sub-arrays with appropriate redundancy elements.
Whereas the prior art and previous discussions have been described mainly in terms of DRAMs, practitioners of the art will fully appreciate that the above configurations and/or architectures are equally applicable to other types of memories, such as SRAMs, ROMs, EPROMs, EEPROMs, Flash RAMs, CAMs, and the like.
OBJECTS OF THE INVENTION
Accordingly, it is an object of the present invention to provide a fault-tolerant design applicable to any size memory.
It is another object of the invention to use a variable size redundancy replacement arrangement to selectively replace failing elements with redundancy elements of identical size.
It is a further object of the invention to use redundancy units, each of which contain a predetermined number of redundancy elements.
It is still another object of the invention to improve the yield of a chip by dynamically repairing any size memory containing both hard faults and retention faults, by selecting the most effective and efficient repair unit of the most appropriate size to make the repair.
It is yet another object of the invention to simultaneously cure hard faults, retention faults and sub-array faults within the memory, and to accomplish this without curing one type of faults at the expense of the other.
It is a further object of the invention to use this variable size redundancy replacement (VSRR) configuration to replace the conventional fixed size redundancy replacement (FSRR) configuration.
It is a more particular object of the invention to use a VSRR configuration in order to minimize REs and associated circuit requirements.
It is yet a further object of the invention to ensure that the repair of hard and retention faults in a memory is achieved without requiring the expenditure of additional power and without impinging on the speed of the memory.
It is still another object of the invention to provide a fault-tolerant block size redundancy replacement which allows a fault in the block redundancy to be repaired and used with other VSRR units.
It is a further object of the invention to allow a faulty RU having a predetermined plurality of REs to be repaired with a VSRR unit having less REs than that predetermined plurality.
It is yet a more particular object of the invention to repair all the faults in the memory device and in the VSRR units in parallel, while maintaining a simple, fast and low power design.
SUMMARY OF THE INVENTION
A primary aspect of the present invention is to provide a new and improved redundancy configuration known as a variable size redundancy replacement (VSRR), allowing for the use of a more efficient and effective replacement unit (RU) which is fully adaptable to the size of the defect. This improved VSRR is intended to eliminate the drawbacks of the more conventional FSRR (Fixed Size Redundancy Replacement) configuration that uses fixed size replacement units, regardless of the number or the size of the defects.
In accordance with one aspect of the invention, there is provided a fault-tolerant memory device that includes: a plurality of primary memory arrays having each a plurality of elements; a plurality of independently controlled variable size redundancy units coupled to the primary memory arrays, the variable size redundancy units having each a plurality of redundancy elements; and controlling means for replacing defective elements in the primary memory arrays with at least one of the variable size redundancy units, wherein the redundancy elements in the at least one variable size redundancy unit replace a corresponding number of the defective elements in the primary memory array.
In accordance to another aspect of the invention, there is provided a fault-tolerant memory device that includes: a plurality of primary memory arrays having each a plurality of elements; a plurality of variable size redundancy units coupled to each of the primary memory arrays, the variable size redundancy units having each a plurality of redundancy elements; and controlling means for replacing defective elements in each of the primary memory arrays, wherein the elements in at least one of the variable size redundancy units are coupled to each of the primary memory arrays.
In accordance with a third aspect of the invention, there is provided a fault-tolerant memory device that includes: a plurality of primary memory arrays having each a plurality of memory elements; at least one variable size unit coupled to the plurality of primary memory arrays, the at least one redundancy array including: a plurality of independently controlled variable size units, the variable size units having each a plurality of memory elements; and controlling means for replacing defective elements in the primary memory arrays with at least one of the variable size units, wherein the variable size unit replaces the defective primary memory elements in accordance to the number of the defective elements.
In accordance with a fourth aspect of the invention, there is provided a fault-tolerant memory device that includes: a plurality of primary memory arrays having each a plurality of memory elements; at least one variable size redundancy unit coupled to the plurality of primary memory arrays, the size of the redundancy unit being at least equal to one of the primary memory units; and a priority decoder for repairing defects in at least one of the variable size redundancy units and for replacing one of the defective primary arrays with the repaired redundancy unit.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned objects, aspects and advantages of this invention and the manner of attaining them will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, the description of which follows.
FIG. 1a shows a schematic representation of a memory provided with a conventional FSRR intra-block replacement scheme, and showing how failing rows in the various sections of the memory are corrected with REs replacing failing ones in each corresponding section.
FIG. 1b shows a schematic diagram of a memory provided with a conventional FSRR flexible redundancy replacement scheme, wherein an array of REs clustered at one end of the memory is used to selectively replace failing rows anywhere within the memory.
FIG. 1c shows a schematic diagram of a memory provided with a conventional block FSRR scheme, wherein a good block formed by a plurality of REs replaces a block of equivalent size within the memory.
FIG. 2 shows a schematic diagram of a VSRR (Variable Size Redundancy Replacement) architecture memory which dynamically allocates RUs depending upon the type and size of fault present therein, according to the present invention.
FIG. 3 is a schematic diagram of an overview of a 256 Mb DRAM showing how the VSRR configuration is used in a typical DRAM.
FIG. 4a shows a control circuit applicable to the VSRR configuration, according to the present invention.
FIG. 4b is a timing diagram applicable to the VSRR configuration shown in FIG. 4a.
FIG. 5a is a schematic of a block diagram of the redundancy unit control decoder, according to the present invention.
FIG. 5b is the timing diagram applicable to the block diagram of FIG. 5a.
FIG. 6a depicts a typical fuse latch arrangement FLAT and a master fuse latch arrangement MFLAT controlled by the circuitry shown in FIGS. 4a and 5a, for replacing faulty elements in the memory.
FIG. 6b is the timing diagram applicable to the block diagram of FIG. 6a.
FIG. 7 is a schematic diagram of an embodiment applicable to the block FSRR architecture of FIG. 1c, wherein a RE in a line redundancy array corrects defects in both, the primary memory array and in the redundancy block array.
FIG. 8a is a schematic diagram of the priority decoder used for the line and block redundancy configuration of FIG. 7.
FIGS. 8b-1 and 8b-2 are timing diagrams applicable to the block diagram shown in FIG. 8a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 2, there is shown a schematic diagram of a memory provided with a variable size redundancy replacement (VSRR) configuration. Unlike the FSRR configuration, wherein each RU comprises the same number of REs, the VSRR arrangement includes a plurality of RUs, each containing a variable number of REs. Moreover, in the VSRR arrangement, all the REs in any RU are simultaneously replaced in any given repair. By way of example, RU 0-7 (i.e., RU 0 , RU 1 , RU 2 , RU 3 , RU 4 , RU 5 , RU 6 , RU 7 ); RU 8-11 (i.e., RU 8 , RU 9 , RU 10 , RU 11 ); RU 12-13 (i.e., RU 12 and RU 13 ); RU 14 and RU 15 may consist of 1, 2, 4, 8, and 32 REs, respectively. Any RU 0-7 will repair a single bit fault. Any of the RU 8-11 will repair a fault caused by a missing bit-line or a short occurring between elements. RU 12-13 , RU 14 and RU 15 are preferably reserved for handling larger faults, such as a defective decoder, and the like. The RUs are controlled by their corresponding redundancy unit control circuit RUCNT, preferably located adjacent to the redundancy block.
VSRR allows the most effective and efficient RU to be used for the repair while minimizing any penalty in the RE area allocated for that purpose. Shown below (Table I) is a comparison between the FSRR and VSRR configurations depicting, for each category, the total number of elements and redundancy unit control circuits RUCNT that are required for repairing a hypothetical fail distribution. Let the domain be defined as requiring the repair of one 32-element-fault, one 8 element-fault, two 4-element-faults, four 2-element-faults, and eight 1-element-faults.
TABLE I.sup.1______________________________________ # of Faults 1 1 2 4 8Fault Size 32 8 4 2 1 Total______________________________________VSRR 32/1 8/1 8/2 8/4 8/8 64/16FSRR 32/8 8/2 8/2 16/4 32/8 96/24______________________________________ .sup.1 number of REs/number of RUs
The above Table assumes FSRR requiring four elements, with one decoder to be replaced regardless the size of the fault. To repair all the assumed failures, FSRR requires 96 REs and 24 redundancy RUs, whereas VSRR requires only 64 REs and 6 RUs. More particularly, referring to column 2 of TABLE 1, there is shown a total of one 32 clustered defect that needs replacing. Under VSRR, one unit comprised of 32 REs is sufficient to repair the defect. Under FSRR, eight 4-REs would be required to achieve the same result. By way of a second example, referring to column 6 of TABLE 1, there are 8 single bit faults that need replacing. Under VSRR, eight 1-REs will suffice, whereas under a. FSRR configuration, there will be a need for eight 4-REs to achieve the same result.
Referring now to FIG. 3, there is shown a schematic block representation of a 256 Mb DRAM chip 10 consisting of sixteen 16 Mb units 15. For purposes of discussion, it is assumed that the 16 Mb unit 15 defines a `domain`, i.e., a fault which can be repaired within the 16 Mb unit, and which is to be referred, hereinafter, as a flexible redundancy replacement in the 16 Mb domain. The redundancy configuration, according to the present invention, applies equally well to both, the intra-block replacement and to the flexible redundancy replacement, by designing in each configuration a menu of variable sized RUs that are to replace clusters of defects. The 16Mb unit, having 8,192 (16×512 per 1 Mb block) wordlines (WL), consists of sixteen 1 Mb blocks (sub-arrays), each having 1M cells. Looking to the right of FIG. 3, every cell forming the memory array consists of an NMOS device 20 and a capacitor 25. To each wordline WL are coupled the gates of 2,048 NMOS devices 20. There are 512 WLs present in the lMb block (i.e., 512 WLs×2,048 cells), but only one is selected when a particular 1 Mb (out of 16) block is activated. (Note: only one WL out of 8,192 is active in the 16 Mb unit). The capacitive charge stored in capacitor 25 is transferred to the corresponding bitline BL. Sense amplifier 28 amplifies the charge on bitline BL. The amplified bit information (i.e., the data) is selected by the corresponding column address (not shown), and is transferred to a Data Output circuit (not shown).
Unlike the conventional intra-block replacement, each 1 Mb block is devoid of any redundancy wordlines (RWLs). A 128 Kb redundancy block with a sixteen variable size redundancy unit RU 0-15 is designed for the 16 Mb unit to replace defective WLs in any of the sixteen 1 Mb blocks. Each RU 0-7 (redundant WL, RWL 0-7 ) consists of a single redundant wordline RWL. Correspondingly, each RU 8-11 (RWL 7-15 ) includes four RWLs (RWL 16-23 ), each RU 12 (RWL 24-31 ) and each RU 13 (RWL 32-63 ) include four RWLs. RU 14 and RU 15 each consist of eight and thirty-two RWLs, respectively. This makes it possible to select the most effective and efficient RU, depending on the size of the fault, thereby increasing the reliability of the unit in the presence of hard faults and retention faults. Referring back to the previous example, enabling the redundancy circuitry 24 disables all the 8,192 WLs in the primary 16 Mb array 19. Instead, 1 out of the 64 RWLs (redundant WL) in the 128 Kb redundancy block 22 is activated. The operation of the redundancy combination previously described comprising NMOS devices 20, capacitors 25, and sense amplifiers 28 also applies to the redundancy combination 30-35-38. The detailed operation of this control circuitry is described next.
The wordlines in the sixteen 1 Mb blocks and the RWLs in the redundant blocks are controlled by the appropriate variable size RU control circuit RUCNT 24 of FIG. 4a. For better performance, these are most advantageously positioned at the bottom of the redundancy block.
Referring now to FIG. 4a, showing a block representation of the variable size redundancy replacement (VSRR) control circuitry, the control circuitry includes wordline decoders (WLDEC); redundancy wordline decoders (RWLDEC); variable redundancy unit control circuits (RUCNT), represented as RUCNT 0-7 , RUCNT 8-11 , RUCNT 12-13 , RUCNT 14 , and RUCNT 15 ; wordline driver (WLDRV) and redundancy wordline driver (RWLDRV). To illustrate the operation of the VSRR configuration of the present invention and simplify the discussion, let us presume that only one of either, a WL (out of 8,192 in the 16 Mb primary array 19) or a RWL (out of 64, in redundancy block 22), is active in the 16 Mb unit 15 (FIG. 3). Practitioners of the art will readily appreciate that two or more WLs may be activated within the 16 Mb units, at the expense of only minor modifications.
The detailed operations of 1) standby mode, 2) normal active mode, and 3) variable redundancy active mode, are described hereinafter.
FIG. 4b shows the timing diagram for the most relevant signals: address ADDs, node N, node N R , WLON, WL disable signal bWLDIS, RWLEs, WL, and RWL, referred to in FIG. 4a.
While in standby mode (i.e., when the chip is not enabled), the control line WLON remains at a low, which disables all the WLs and RWLs (all at 0), regardless of the state (i.e., "don't care" condition) of the WLDEC output N, of RWLDEC output N R , and of the output RWLE of RUCNT. When the chip is enabled (i.e., in the active mode), either WL or RWL is active (but not both). When WL is enabled, the chip enters the so-called normal active mode. Alternatively, when RWL are activated (which disables WL), the chip is referred to as being in the redundancy active mode.
In a normal active mode, all the redundant word lines enable signal RWLE remain at a low, keeping the output signal (bWLDIS) of the wordline disable circuit WLDISGEN at a high. The detailed operation of the RWLE signal generation will be described hereinafter. When the 16 Mb unit 15 (FIGS. 3 and 4) is enabled, 13b address information is transferred to WLDEC, enabling one node N out of 8,192. This makes it possible to activate one WL out of the 8,192 when the signal WLON switches to a high.
While in redundancy mode, activating the redundant wordlines RWL is controlled by a two-path decoding: a) through RUCNT, and b) through RWLDEC. As previously explained, a RU consisting of several REs is controlled by the appropriate RUCNT. Each RE in the RU is controlled by the alternate path b), i.e., RWLDEC. Both decoding paths work in parallel, and a final decoding of the results of RUCNT and RWLDEC takes effect in the RWLDRV. A detailed description of the operation while in redundancy mode is described next.
The redundancy mode is typically detected by RUCNT, which activates the appropriate RWLE prior to the arrival of a signal on WLON. (The detection phase is referred to as the redundancy match detection phase). This forces the signal bWLDIS at the output of WLDISGEN to switch to 0, thereby inhibiting the wordlines in the 16 Mb unit from becoming active. During the RUCNT redundancy match detection phase, an alternate path for selecting an RE in at least one RU is decoded in RWLDEC. Concurrently, the appropriate RWLDEC is activated with address information, switching the corresponding N R to a 1. The number of address bits used for RWLDEC sets the bits required for decoding the appropriate number of REs in the corresponding RU. This path is independently controlled no matter if it is in a redundancy mode or in normal mode. The final decision to activate an RWL is determined by the decoding result of N R and RWLE in RWLDRV. The aforementioned two path decoding makes it possible for one RWL to become active (without incurring in speed penalties) by means of appropriate addressing, which had already been previously decoded when WLON switched to a high.
RWLDEC is provided with a variable size redundancy decoder that makes it possible to implement the VSRR configuration of the present invention. By way of example, for a single wordline replacement no decoder is required, and the RWLE signal generated by the RUCNT directly controls the appropriate RWLE driver. A 2 WL, 4 WL, 8 WL, and 32 WL replacement requires 1 bit (1b), 2 bits (2b), 3b, and 5b decoders, respectively, at the corresponding RWLDEC. This, in turn, activates the appropriate node N R in accordance with address inputs ADD.
Referring now to FIGS. 5a and 5b respectively, there is shown a block diagram and the timing diagram of a single RU control circuit RUCNT. This circuit is provided with a plurality of fuse latches FLATs driving a decoder (i.e., an AND gate). The only difference between a conventional FSRR control circuit and the VSRR control circuit RUCNT resides in the number of fuses that are required for each variable replacement. It is determined by the number of bits for each RUCNT required by the VSRR configuration. Additionally, one master fuse MFLAT is also needed for each RUCNT.
For a single bit replacement RUCNT 0-7 , 13 bits are needed to decode one of the 8 k wordlines in the 16 Mb unit. This requires 13 FLATs and one master FLAT (MFLAT), labeled 13F+1MF in FIG. 4a. For a 2 WL replacement RUCNT 8-12 , one bit can be saved, resulting in 12 fuses and one master fuse (12F+1MF). For 4 WL, 8 WL and 32 WL replacements, 11, 10 and 8 fuses and one master fuse are, respectively, required per RUCNT (11F+1MF, 10F+1MF and 8F+1MF). A detailed description of its operation follows next.
In order to enable a RUCNT, the master fuse needs to be blown. As long as the master fuse remains intact, the output MF of MFLAT (FIG. 5b) is 0. The output RWLE of the AND gate remains at 0, regardless of the address. When the master fuse is blown (MF set at 1), RWLE is controlled by the combination of outputs of FLAT, i.e., FADD. FADD switches to 0 when the corresponding address input ADD fails to match the programmed fuse information. Alternatively, FADD switches to 1 when the corresponding ADD matches the programmed fuse information. Only when all the fuse programmed addresses match the ADD inputs, and MF is blown, thereby RWLE switching to 1.
Referring now to FIG. 6a, there is shown a schematic diagram for the fuse latch FLAT, wherein FLAT is depicted as an address-fuse comparator. A CMOS latch, formed by 60, 65 and 68, is set by devices 80 and 82 during the power-up phase of the chip by FPUP and FPUN, as shown in the diagram of FIG. 6b. If fuse 83 is not blown at power-up, nodes N0, N1, and N2 are set to 0, 1 and 0, respectively. Alternatively, if fuse 83 is blown, nodes N0, N1 and N2 are set to 1, 0, and 1, respectively. Those states of nodes N0, N1 and N2 are latched in CMOS latch circuits 60, 65 and 68. Either of the CMOS transfer gates 70 and 75 opens up, depending on the state of nodes N1 and N2. ADD and ADD (inverted by circuit 69) are coupled to the CMOS transfer gates 70 and 75, respectively. As long as the fuse remains intact (i.e., at 0), the output FADD of FLAT 47 follows ADD. When the fuse is blown, FADD follows ADD. FADD switches to 1 when both ADD and the fuse are either 0 or 1, resulting in an address and fuse match detection.
Within the circuit FLAT of FIG. 6a is included the circuit MFLAT (or Master FLAT), which is shown alongside with appropriate timing curves (FIG. 6b). The CMOS latch, formed by 60, 65 and 68, is set during the power-up phase of the chip by FPUP and FPUN, as depicted in the diagram. If, during power-up, fuse 83 is not blown, then N0, N1 and N2 (also referred to as MF) switch to 0, 1, 0, respectively. With MF at 0, the AND gate in RUCNT (FIG. 5a) is disabled . If, on the other hand, fuse 83 is blown, then, at power-up, N0, N1 and N2 (also referred to as MF) switch to 1, 0, 1, respectively, while MF is at 1, which enables the AND gate in RUCNT (FIG. 5).
Referring now to FIG. 7, there is shown another embodiment of the present invention, namely, a fault tolerant block redundancy replacement configuration applicable to the conventional block architecture of FIG. 1c. A primary memory array is illustrated therein, structured as a plurality of sub-arrays 0-15 (labeled 100-115). A block redundancy array 150, preferably positioned at the bottom of the primary memory array, is assumed to contain at least one defect. Let it be further assumed that sub-array 114 within the primary memory array contains a large number of faults (labeled X). Block redundancy 150 can, in this instant case, be used to replace sub-array 114 in its totality.
Practitioners of the art will fully realize that defects can occur in any of the sub-arrays that form the memory device, irrespective if a primary memory array, a redundancy block array or a redundancy unit (in the VSRR configuration). As such, the presence of a defect in the redundancy block array can pose serious performance problems in any replacement scheme, since redundancy arrays are presumed to be good, when in reality they may be defective.
In accordance to the present invention, and further with reference to FIG. 7, the redundancy array 130 is now structured within the memory device as having the capability of correcting defects within the block redundancy array, allowing a defective block redundancy array to replace large portions of the primary array. To enable such a repair, redundancy block 150 is tested, and any defects found are repaired by assigning RUs contained in the variable redundancy array 130.
The configuration of FIG. 7 may generally be viewed as a combination of the inventive concepts described in the VSRR configuration of FIG. 2, as applied to the block redundancy arrangement shown in FIG. 1c. RUs within the variable redundancy array 130 can now cure defects within any of the sub-arrays 100-115 or in the block redundancy array 150. If the number of defects within a sub-array, e.g., 114, is found to exceed a predetermined number, initially, block 150 is made defect free, and only then it is used to replace sub-array 114.
Referring now to FIG. 8a, there is shown a schematic diagram of the priority decoder, according to the present invention, that orchestrates the replacement of defective arrays within the memory with a defect-free block redundancy array. The priority decoder allows primary array 114 and block redundancy array 150 to be simultaneously checked for a redundancy replacement, resulting in no-access penalty. Therein is also depicted a block diagram which includes: two variable size RU control circuits RUCNT0 and RUCNT1, a block redundancy control circuit RUCNT BLK , wordline disable generator WLDISGEN, wordline driver WLDRV, redundancy wordline driver RWLDRV and block redundancy wordline drivers BWLDRV. WL decoder WLDEC, RWL decoder RWLDEC, and block redundancy WL driver are not shown in FIG. 8a, although a parallel may be drawn to corresponding elements in FIG. 4a, via nodes N and N R . The basic control flow is the same as that described with reference to FIG. 4a.
Four operations are applicable to the above configuration: 1) normal operation, 2) variable redundant operation, 3) block redundancy operation, and 4) a replacement mode operation, wherein faults in the block redundancy are replaced by a VSRR arrangement. During operations 1) and 2), the output RWLE BLK of RUCNT BLK remains at 0, allowing WLs and RWLs to be controlled in the manner described for VSRR in reference to FIG. 4.
While in mode 1), all RWLEs remain at 0 and bWLDIS at 1. Accordingly, when WLON switches to 1, the corresponding WL is enabled by the appropriate node N.
While in mode 2), the appropriate RWLE switches to 1, forcing bWLDIS to 0. As a result, when WLON switches to 1, the corresponding RWL selected by the appropriate RWLE and node N R switches to 1. The switch of RWLE to 1 makes bWLDIS switch to 0, disabling the appropriate WL in the primary array.
While in mode 3), all RWLEs remain at 0, keeping bWLDIS at 1. Alternatively, RUCNT BLK detects a block redundancy mode impacting RWLE BLK depending on the state of the node N R . This enables BWLDRV and disables WLDRV. Accordingly, when signal WLON switches to 1, the corresponding RWL in the block redundancy is activated, disabling WL.
While in mode 4), RUCNT BLK and a variable RUCNT detect the block redundancy replacement mode and the VSRR mode, simultaneously. However, only RWLDRV (in the VSRR configuration) is enabled, because of the high value taken by bWLDIS, concurrently disabling WLDRV and BWLDRV. It follows that VSRR takes precedence over the block redundancy replacement mode. Alternatively, VSRR has a higher priority than the block redundancy replacement, which is achieved with bWLDIS gating both WLDRV and BWLDRV (a function which is referred to as priority decoding). It is, therefore, possible to repair faulty elements with other VSRR means even when a faulty element is part of a redundancy block. There is no access penalty because the match detections of the block redundancy and of the VSRR can work simultaneously, although the decision of either operation is made only much later with the priority decoder. The above described concept can be effectively applied to allow a fault-tolerant variable size RU containing a number of defective REs to repair defective RUs with other RUs of smaller size.
The present invention described herein may be designed in many different memory configuration schemes. While the present invention has been described in terms of various embodiments, other embodiments may come to mind to those skilled in the art without departing from the spirit and scope of the present invention. The invention should then be measured in terms of the claims that follow.
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A variable size redundancy replacement (VSRR) arrangement for making a memory fault-tolerant. A redundancy array supporting the memory includes a plurality of variable size redundancy units, each of which encompasses a plurality of redundancy elements. The redundancy units, used for repairing faults in the memory, are independently controlled. All the redundancy elements within a repair unit are preferably replaced simultaneously. The redundancy elements in the redundancy unit are controlled by decoding address lines. The variable size that characterizes this configuration makes it possible to choose the most effective redundancy unit, and in particular, the one most closely fitting the size of the cluster of failures to be replaced. This configuration significantly reduces the overhead created by added redundancy elements and control circuitry, while improving the access speed and reducing power consumption. Finally, a fault-tolerant block redundancy controlled by a priority decoder makes it possible to use VSRR units for repairing faults in the block redundancy prior to its use for replacing a defective block within the memory.
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RELATED APPLICATIONS
[0001] This application claims priority to German application serial number DE 10 2005 027 120.0 on Jun. 10, 2005, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for optically imaging and analyzing wafers having structures produced by SAWs.
BACKGROUND OF THE INVENTION
[0003] The surface of a semiconductor wafer to be inspected comprises dies applied in a structure. A plurality of dies is applied to the wafer with each exposure process. The area of this plurality of dies is the stepper area window (SAW), i.e. the stepper exposure area, which periodically progresses on the surface of the wafer.
[0004] A method is known wherein the imaging window of a scanner is scanned along the period progression direction of the SAWs across the wafer. Herein those windows imaged within the distance of the length of a progression period are compared to each other. In a good wafer no differences should arise in this comparison due to the periodic uniformity of the structures. Should there be a defect on the wafer surface, it will show as a difference in the compared images.
[0005] To apply the maximum number of semiconductor elements on the wafer, there is usually a displacement of the SAWs in the edge area of the wafer which interrupts the periodicity of the SAWs.
[0006] A drawback in the prior art is that intentional deviations from the uniform periodicity of the structures cannot be taken into account in the inspection.
SUMMARY OF THE INVENTION
[0007] It is therefore an object of the present invention to further develop a method of the initially mentioned type in such a way that the optical inspection of a wafer having SAWs in a displaced arrangement can be carried out by simple means.
[0008] This object is achieved by a method for inspecting a wafer with a first area of SAWs periodically arranged in a period direction and with at least a second area of SAWs arranged with a displacement of one displacement distance with respect to the first area in a direction normal to the period direction, the object is achieved by the following method steps:
optically detecting a first area of the wafer by moving an imaging window in the period direction across the first area of the wafer until the adjacent second area is reached, and simultaneously imaging partial images in an order following the period direction during the movement, displacing the imaging window relative to the wafer by one displacement distance in a direction normal to the period direction, optically imaging the second area of the wafer by moving the displaced imaging window in the period direction across the second area of the wafer, and simultaneously imaging partial images in an order following the period direction during the movement, and evaluating the images by comparing partial images.
[0012] The second area can be, for example, the outer area of the surface of a wafer delimited by a chord. Either the imaging window or the wafer or both can be displaced.
[0013] According to the invention the above mentioned object is also achieved in a method of inspecting a wafer with a first area of SAWs periodically arranged in a first period direction, and with at least one second area of SAWs periodically arranged in a second period direction normal to the first period direction, by the following method steps:
optically imaging the first area of the wafer by moving an imaging window in the period direction across the first area of the wafer, and simultaneously imaging partial images arranged in the period direction during the movement, rotating the imaging window relative to the wafer by 90 degrees, optically imaging the second area of the wafer by moving the displaced imaging window in the period direction across the second area of the wafer, and simultaneously imaging partial images in an order following the period direction during the movement, evaluating the images by comparing partial images.
[0018] The first area and the second area can have a common overlapping area. Either the imaging window or the wafer or both can be moved during the rotation.
[0019] Suitably it is provided that partial images having the same period position are compared with each other in the comparing step.
[0020] In a good wafer this is advantageous in that essentially identical partial images have to be compared with each other. Usually a difference image is formed. This is especially quick.
[0021] Advantageously it is provided that when the partial images are compared, the difference of the partial images is formed.
[0022] By forming the difference of the essentially identical partial images a particularly quick comparison of the partial images is possible. Defects show up in that the difference between two partial images is not zero.
[0023] Preferably it is provided that the evaluating step is at least partially carried out during the imaging.
[0024] This is advantageous in that not the whole image of the wafer has to be intermediately stored in the imaging step, but partial images having the same period position can be compared already after one period length has been intermediately stored. For example, only the overall difference image of the wafer will then be stored in memory.
[0025] According to one embodiment of the invention it is provided that essentially the whole width of the wafer is covered by the imaging window in the imaging step.
[0026] According to one particular embodiment of the invention it is provided that the imaging window is imaged on a linear array detector in the imaging step.
[0027] This is advantageous in that an area of the wafer is imaged in one go according to the manner of a scanner.
[0028] It is advantageously provided that the individual images of the linear array detector are imaged as partial images in the imaging step.
[0029] The association of a line of the detector to a partial image leads to a particularly efficient memory management. The partial images need not be composed of further sub-partial images.
[0030] Ideally it is provided that pixels having the same position in the linear array detector are compared to each other in the evaluating step.
[0031] The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The invention will be explained in more detail in the following with reference to schematic drawings of one embodiment. The same reference numerals will be used in the individual figures to indicate the same elements. In the drawings:
[0033] FIG. 1 shows a stepper area window (SAW) with dies,
[0034] FIG. 2 shows a wafer with a completely uniform arrangement of SAWs,
[0035] FIG. 3 shows the exposure order of the SAWs on the wafer,
[0036] FIG. 4 shows a wafer having two areas of periodically arranged SAWs,
[0037] FIG. 5 shows a first embodiment of the method according to the present invention, and
[0038] FIG. 6 shows a second embodiment of the method according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] FIG. 1 shows a stepper area window (SAW) 20 . An SAW is a stepper exposure area. This is the portion of the surface of a semiconductor substrate which is structured during the same exposure process. It comprises one or more dies or other semiconductor elements. In the case shown, for example, four dies 21 “A”, “B”, “C”, and “D” are applied.
[0040] FIG. 2 shows a wafer 10 with SAWs 20 in a fully periodical arrangement. The imaging window 30 of an imaging apparatus, such as a linear array detector, not shown, is depicted overlying the wafer. The imaging window has the width of about the diameter of the wafer, but at least of the extension of the applied SAW structures. It is provided that the imaging window 30 aligned at right angles to the SAW structures is moved across the SAW structures in the movement direction 51 . The first position 31 , a second position 32 , and an end position 33 of the imaging window are shown in the figure across the wafer. The SAWs are periodically arranged on the wafer in a period direction 50 . The indicated first viewing area 41 and the second viewing area 42 illustrate the periodicity of repetitive similar dies “A” or “C”. The first position of the imaging window 31 and the second position of the imaging window 32 are spaced at one period length from each other. They therefore image the same SAW structures. Defects in any SAW structure can therefore be detected by a comparison with the other SAW structure. This is the illustrated basic method for inspecting a wafer.
[0041] FIG. 3 shows a wafer with applied SAWs and the exposure order 22 of the SAWs. The two SAWs at the beginning and end of each exposure order have their period displaced with respect to the remaining SAWs in order to maximally fill with dies the area cut off by a chord at the edge with two instead of three exposure steps. On the left, dies “B” and “D”, and on the right dies “A” and “C” are applied.
[0042] FIG. 4 shows a wafer structured with SAWs and exposed in the manner according to FIG. 3 . The SAWs in the first area 11 indicated with broken lines, have a periodicity with respect to each other in the period direction 50 . A second area 12 , however, also indicated in broken lines, has its periodicity displaced with respect to the first area by one displacement length in a displacement direction 52 normal to the period direction 50 of the first area 11 . The displacement is particularly noticeable in the indicated second viewing area 42 and the indicated third viewing area 43 .
[0043] FIG. 5 shows a wafer structured in the manner of FIG. 4 and also visualizes the first method according to the present invention. The narrow imaging window 30 of a linear array detector extending across the whole width of the wafer is in a position at the beginning of the first area. This imaging window 30 is now moved parallel to the period direction 50 of the SAWs in a movement direction 51 up to a first intermediate position 35 at the end of the first area and at the beginning of the second area, for imaging the wafer structures. Following this, the imaging area is displaced from its first intermediate position in a direction normal to its previous movement direction by the displacement length of the SAWs in the second area in a second intermediate position 36 . From there the imaging window is further moved in the original movement direction 51 across the second area until its end position 33 at the end of the second area 52 is reached. Herein similar wafer structures or dies always have the same distance from the lateral end of the imaging area or row of the linear array camera; here in the second viewing area 42 and the third viewing area 43 the dies “A” and “C” are shown. This enables an easy comparison of the structures arranged in the second area with those arranged in the first area. By displacing the imaging area at the boundary between the first and second areas, the periodicity interrupted in the exposure by the displacement of the second area with respect to the first area is in a way technically restored in the imaging step.
[0044] FIG. 6 shows another wafer structured with SAWs as in FIG. 4 . The wafer has a further first area 13 and a further second area 14 , each defined by broken lines. The areas are characterized in that within the areas the periodicity of the SAWs is given. The areas partially overlap. The periodicity of the further first area 13 corresponds to the periodicity of the first area 11 of FIG. 4 . The periodicity of the further second area 14 is aligned in a vertical, second period direction 53 with respect to the periodicity of the further first area. To do this, the second method according to the present invention provides that the imaging window 13 for imaging the side of the further first area 13 shown on the left in the figure is moved in a direction 51 parallel to the period direction of this area up to the right side of this area in a first process step. In a second step, the wafer is rotated beneath the imaging area about its center axis in the sense of rotation 54 by 90 degrees. This is how the imaging area arrives at its further second intermediate position 37 . For clarity, the wafer was not rotated in the figure, but the imaging area is shown as rotated in the reverse direction. Herein the imaging area comes to a position at the one side of the further second area in a direction normal to its period direction. From there the imaging area is moved in the second movement direction 55 for imaging parallel to the second period direction of the further second area in a third method step. In this method only partial images from each same area are compared to each other. While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
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The present invention relates to a method of inspecting a wafer, wherein the wafer has a first area of periodically arranged SAWs and at least one second area of SAWs displaced with respect to the first area. The method comprises the steps of optically imaging the first area of the wafer by moving an imaging window in the period direction, displacing the imaging window relative to the wafer, optically imaging the second area of the wafer by moving the displaced imaging window in the period direction, and evaluating the image by comparing partial images.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a calender, particularly for webs of textile fabric, non-woven fabric, or synthetic fabric, with a frame and a first roll, a second roll and a third roll mounted in the frame, wherein the third roll forms during operation a single nip either with the first roll or with the second roll.
[0003] 2. Description of the Related Art
[0004] A calender of the above-described type is sold by Kleinewerfers Textilmaschinen GmbH in the form of a three-roll calender with rolls arranged one above the other. The nip is in this calender formed either between the upper roll and the middle roll or between the lower roll and the middle roll. The two different pairings of rolls are necessary in order to be able to switch over as soon as possible and without major reassembly from one manner of treatment to another manner of treatment. For example, it may be necessary to treat the fabric web with different surface qualities of the upper and the lower rolls. Another situation occurs when it is desired to change the treatment temperature of the fabric web. Since the temperature change in the heated roll can be carried out only at about 1° C. to 2° C. per minute in order to avoid undue thermal stresses, a temperature change of 40° C. will take a relatively long time. On the other hand, if it is possible to change to a roll which already has the required temperature, the time required for changing between the two types of treatment is drastically shortened.
[0005] Consequently, in the known calender, the travel path of the fabric web is changed when changing from one manner of treatment to another. Thus, if the fabric web has been fed to the upper nip, i.e., the nip between the upper roll and the middle roll, the fabric web is then supplied for the changed treatment to the lower nip, i.e., the nip between the lower roll and the middle roll. The nip which is not in use remains open. A calender of the above-described type has been found acceptable in principle for different treatment possibilities of fabric webs. However, the change of one type of treatment in one nip to another type of treatment in the other nip is relatively cumbersome. In particular, the path along which the fabric web is guided must be changed. This is true for the entry side as well as the exit side. If the fabric web is a non-woven fabric which is to be bonded in the nip, for example, a supply belt on which the fabric is supplied to the nip must be pivoted. The fabric web must either travel with a different travel path through cooling rolls which as a rule are arranged at the exit of the nip, or the position of the cooling rolls must also be changed.
[0006] A calender of the above-described type is also known from DE 37 12 276 C1. In one embodiment of this calender, three rolls are arranged one above the other, wherein the middle roll can be moved either upwardly to form a nip with the upper roll, or downwardly to form a nip with the lower roll. The fabric web is supplied through a pivotable supply unit whose supply path ends either a short distance below the upper roll or a short distance above the lower roll. The fabric web leaving the respective nip is guided either from below or from above around a guide roll and leaves the calender in a slightly upwardly or downwardly inclined direction.
SUMMARY OF THE INVENTION
[0007] It is the primary object of the present invention to facilitate the change from one type of operation to another type of operation.
[0008] In accordance with the present invention, in a calender of the above-described type, the first roll is movable between a first work position in which it forms the nip with the third roll and a first parking position, and the second roll is movable between a work position in which it forms the nip with the third roll and a second parking position, wherein the two work positions coincide and the parking positions of each of the first and second rolls is distanced from the third roll by such a distance that a movement of the respectively other roll between the work position and the parking position is possible.
[0009] The statement that the two work positions coincide does not mean that they coincide in the mathematical sense. Smaller deviations are permissible as long as the nip, which is formed by the respective first or second roll which is in the work position with the third roll, produces essentially the same treatment result, independently of which roll is at a given time in the work position. Of course, this is only true if the first and second rolls are equal. However, the first and second roll will normally be of different construction. The differences may be in the surface structure or in the material if the first or second rolls or both rolls are constructed as engraved rolls. The differences may also be in the temperature or in other physical properties. A change in the type of operation from a treatment in the nip between the first and second rolls to a treatment in the nip between the second and third rolls is relatively simple. In particular, it is not necessary to change the entry travel path or the exit travel path of the fabric web. It is merely necessary to move the roll which prior to the change of the type of operation was in the work position into its parking position and to move the other roll from its parking position into the work position. Such movements can be carried out substantially simpler than the change of a travel path. It is merely a prerequisite that the roll in the parking position leaves room for the movement of the other roll from the work position into the parking position and vice versa.
[0010] In accordance with a preferred embodiment, the first roll and the second roll are each movable together with their drive and possibly supply units. Accordingly, each roll when moved takes along with it its drive and possibly its supply unit, for example, required for achieving a predetermined temperature. Accordingly, when changing from one type of operation with the first roll to another type of operation with the second roll, it is actually only necessary to move the respective roll. It is not necessary to provide new connections or to connect drives to the respective roll. The roll which is in the parking position can continue to rotate with a rate of rotation independent of the production speed, for example, for cooling the roll.
[0011] In accordance with a preferred embodiment, the first roll is mounted on the frame through a first pivoting lever and the second roll is mounted on the frame through a second pivoting lever, wherein each pivoting lever is pivotable about a pivot axis. The movement of the rolls can be carried out quickly and without problems with a pivoting movement. During the pivoting movement, the pivoting lever is secured to the pivot axis. Consequently, the pivot lever always has a defined position relative to the frame, so that the control of the movement is very simple.
[0012] Each pivoting lever can preferably be secured relative to the frame on the side of a press plane located opposite the pivot axis, wherein the press plane extends through the two roll axes of the rolls forming the nip. This takes into consideration that for treating the fabric web the third roll is pressed with a certain force against the roll located in the work position. The first or second roll located in the work position is secured through the pivot axis to the frame. However, without the additional attachment of the pivoting lever, a relatively large moment would act on the pivoting lever, wherein the moment is difficult to absorb. By attaching the pivoting lever to the frame on both sides of the press frame, this problem is eliminated. The attachment can also be carried out indirectly at least on one side.
[0013] In accordance with a preferred feature, the pivoting lever located in the work position can be locked to the pivoting lever in the parking position. This does not result in an indirect locking of the pivoting lever in the working position to the housing. Rather, the pivoting lever is locked directly through the respectively other pivoting lever. However, this type of connection forms a triangle formed by the pivot axes of the two pivot levers and the locking point between the two pivoting levers. Such a triangle provides sufficient stability for supporting the pivoting lever, or the first or second roll which may be in the work position, against the forces exerted by the third roll.
[0014] In accordance with a preferred feature, each pivoting lever has a first bore which can be aligned with a second bore in the respectively other pivoting lever, wherein a bolt can be inserted into the two bores parallel to the pivot axes. Consequently, each pivoting lever has two bores, wherein the bore of one pivoting lever is in alignment with the other bore of the other pivoting lever if the one pivoting lever is in the work position. The insertion of a bolt through the aligned bores poses no problems. The bolt can be inserted either manually or a hydraulic cylinder or another drive can be used. The arrangement of bores permits a quick and reliable locking between the levers.
[0015] Each pivoting lever preferably has an adjusting device for its work position. The adjusting device has two purposes. First, the adjusting device determines the position of the pivoting lever relative to the frame in such a way that the roll located at the respective pivoting lever is in the correct position relative to the third roll. On the other hand, the adjusting device also ensures that the first bore of the respective pivoting lever in the work position can be aligned with the respective second bore of the other lever in the parking position.
[0016] The adjusting device preferably has a first adjusting unit which cooperates with the frame. This adjusting unit is used to adjust the pivoting angle of the pivoting lever relative to the frame. In principle, the vertical position of this bore in relation to the first bore is adjusted by this adjusting unit.
[0017] The adjusting device preferably also has a second adjusting unit which interacts with the respectively other pivoting lever. The second adjusting unit has basically no influence on the position of the pivoting lever which is in the work position relative to the housing. However, the second adjusting unit forms a limit for the pivoting movement of the pivoting lever in the parking position and, thus, facilitates an adjustment of the second bore of the pivoting lever in the parking position in the horizontal direction, i.e., perpendicularly of the possible movement direction of the first bore of the pivoting lever in the work position. This makes it possible to achieve an alignment of the two bores in a relatively simple manner. The adjustment is basically only necessary during the startup and possibly during a subsequent maintenance operation. The adjustment is not changed when the pivoting lever is pivoted.
[0018] Each pivoting lever preferably has a stop for its parking position. This stop limits the movement of the pivoting lever and the load of the pivoting drive is kept small.
[0019] Each pivoting lever is preferably inclined in its parking position at most to such an extent that the other pivoting lever can be pivoted without collision relative to the first pivoting lever into its parking position. This keeps low any torque which is formed by the center of gravity of the pivoting lever in the parking position and the horizontal distance from the pivoting axis. This eliminates the load on the pivoting drive in the parking position. In the work position, the pivoting lever is already directly or indirectly supported on the frame, so that there is also no load on the pivoting drive in the work position. The pivoting drive actually has only to be used in the phases of movement between the parking position and the work position. Thus, the angle is kept as small as possible.
[0020] The pivoting levers are preferably two-arm levers, wherein the respective roll is arranged on one side of the pivoting lever and a pivoting drive acts on the other side of the lever. As a result, the pivoting drive does not impair the operation of the roll and vice versa. This means that a wide variety of pivoting drives can be used.
[0021] In accordance with an advantageous feature, each pivoting lever is constructed with two walls and surrounds both sides of bearing lug of the frame. This results in a very stable support of the pivoting lever in the frame which reliably prevents tilting of the pivoting lever relative to the housing in a direction other than the pivoting direction.
[0022] In accordance with another preferred feature, each pivoting lever has at its end facing the other pivoting lever a locking plate which can be inserted between the two walls of the other pivoting lever. Also in this case, a very stable connection is obtained when locking the levers by inserting the locking plate between the two walls of the other pivoting lever.
[0023] The rolls are advantageously releasably connected to the pivoting levers. For example, the bearings on which the rolls are rotatably mounted can be fastened through a screw connection to the pivoting levers. This simplifies the exchange of rolls which occasionally becomes necessary.
[0024] The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
[0025] In the drawing:
[0026] [0026]FIG. 1 is a side view of a calender during operation;
[0027] [0027]FIG. 2 shows the calender of FIG. 1 during a change of the type of operation of the calender; and
[0028] [0028]FIG. 3 is a view, on a larger scale, of a locking device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] [0029]FIG. 1 of the drawing shows a calender 1 with a frame 2 and first roll 3 , a second roll 4 , and third roll 5 mounted in the frame 2 . The third roll 5 is mounted in a carriage 6 which can be displaced in the frame 2 by means of a hydraulic cylinder 7 ; in the illustrated embodiment, the displacement of the carriage 6 is in the vertical direction. However, the hydraulic cylinder 7 not only serves for displacing the carriage 6 and the third roll 5 , but also for adjusting the third roll 5 against the first or second roll and for applying a force by the roll 5 against the first or second rolls, as will be explained below.
[0030] The first roll 3 is mounted on a first pivoting lever 8 which can be pivoted about a pivot axis 9 relative to a frame 2 . For this purpose, the first pivoting lever 8 has a pivoting drive 10 . The first pivoting lever 8 is constructed as a two-arm lever. The first roll 3 is mounted on one side of the pivot axis 9 ; in the illustrated embodiment, the first roll 3 is arranged on the right of the pivot axis 9 . The pivoting drive 10 acts on the other side, i.e., on the left in the illustrated embodiment. When the first pivoting lever 8 has been pivoted in such a way as it is illustrated in FIG. 1, the first roll 3 is in its work position, i.e., it forms with the third roll 5 a nip 11 through which a fabric web 12 can be guided and in which pressure and possibly increased temperature can be applied to the fabric web 12 .
[0031] The fabric web 12 is supplied to the nip 11 by means of a screen 13 or by means of another conveying device. This screen 13 may be stationary, i.e., the fabric web 12 is always guided through the nip 11 in the illustrated manner.
[0032] Two cooling rolls 14 , 14 are arranged at the exit side of the nip 11 ; the fabric web 12 is guided partially around each cooling roll 14 , 15 . These cooling rolls 14 , 15 also remain stationary and the fabric web 12 is always guided in the same manner around the cooling rolls 14 , 15 independently of the manner of treatment of the fabric web in the calender 1 .
[0033] The second roll 4 is mounted in a similar manner on a second pivoting lever 18 which can be pivoted about a pivot axis 19 and includes a pivoting drive 20 . As illustrated, the pivoting drives 10 , 20 are constructed as hydraulic cylinders. The pivot axes 9 , 19 are formed by bolts which are attached to the frame 2 . In FIG. 1, the second roll 4 is in the parking position.
[0034] The rolls 3 , 4 , 5 have a diameter in the order of magnitude of 400-900 mm, wherein the third roll 5 as a rule has a slightly smaller diameter than the first roll 3 or the second roll 4 .
[0035] As mentioned above, the third roll 5 is pressed by means of the cylinder 7 against the first roll 3 which is in the work position. Without additional measures, this would result in a pivoting movement of the first pivoting lever 8 . In order to prevent this, the first pivoting lever 8 is locked to the second pivoting lever 18 . This is illustrated in FIG. 2. The first pivoting lever 8 has a first opening 21 provided in a first locking plate 22 which is arranged at the tip of the first pivoting lever 8 , i.e., at that end which is directed toward the second pivoting lever 18 when the first pivoting lever is located in the work position illustrated in FIG. 1. In the same manner, the second pivoting lever has a first opening 23 in its locking plate 24 .
[0036] The first pivoting lever 8 has a second opening 25 . The second pivoting lever 18 has a second opening 26 . Arranged at both second openings 25 , 26 is a hydraulic cylinder 27 , 28 each which acts parallel to the pivot axes 9 , 19 , i.e., perpendicularly of the plane of the drawing in the illustrations of FIGS. 1 and 2.
[0037] When the first pivoting lever 8 has been moved into the work position and the second pivoting lever 18 has been moved into the parking position, the first opening 21 of the first pivoting lever 8 and the second opening 26 of the second pivoting lever 18 are in alignment. As can be seen in FIG. 3, the cylinder 28 can then push a bolt 29 into the openings, so that the first pivoting lever 8 and the second pivoting lever 18 are locked together. This means that the first pivoting lever 8 is indirectly secured relative to the frame 2 . The two pivot axes 9 , 19 and the locking point resulting from the bolt 29 form a triangle which is stable enough to support the first roll 3 relative to forces exerted by the cylinder 7 .
[0038] As FIG. 3 further shows, the second pivoting lever 18 is a double-walled lever (the same is true for the first pivoting lever 8 ), i.e., the pivoting lever 18 has two walls 30 , 31 between which the locking plate 22 of the first pivoting lever 8 can be inserted. In the same manner, the frame 2 is received between the two walls 30 , 31 . The frame 2 may have a smaller thickness and form a bearing lug at this location.
[0039] For ensuring the alignment of the first bores 21 , 23 with the second bores 25 , 26 of the respectively other pivoting lever after a pivoting movement has been carried out, each pivoting lever 8 , 18 has an adjusting device. The adjusting device includes a first adjusting unit 32 , 33 in the form of an adjusting screw. As can be seen in FIG. 1, the adjusting screw 32 of the first pivoting lever 8 rests in the work position against the frame 2 . By changing the length of the adjusting screw 32 , the vertical position of the opening 21 of the first pivoting lever 8 is essentially adjusted.
[0040] The adjusting device further has a second adjusting unit 34 (at the first pivoting lever) and 35 (at the second pivoting lever) which are also constructed as adjusting screws. The adjusting unit 34 at the first pivoting lever 8 limits a pivoting movement of the second pivoting lever 18 toward the first pivoting lever 8 . This essentially secures the position of the second opening 26 in the second pivoting lever 18 in the horizontal direction. Consequently, by an interaction of the two adjusting units 32 , 34 at the first pivoting lever or the two adjusting units 33 , 35 at the second pivoting lever, an alignment of the respective bores 21 , 26 and 23 , 25 can be achieved in a relatively simple manner.
[0041] When the manner of operation is to be changed, i.e., the fabric web 12 is no longer to be treated between the first roll 3 and the third roll 5 , but in a nip between the second roll 4 and the third roll 5 , initially the locking device between the first pivoting lever 8 and the second pivoting lever 18 is released by moving the bolt 29 back by means of the cylinder 28 . Next, the second pivoting lever 18 is pivoted outwardly by means of its pivoting drive 20 , as can be seen in FIG. 2. This movement can be limited by a stop 37 in such a way that the angle of inclination of the pivoting lever relative to the vertical direction is limited to a maximum value; a corresponding stop 36 is provided for the first pivoting lever 8 . This provides sufficient space for making it possible to pivot the pivoting lever 8 past the second roll 4 into the parking position illustrated in broken lines in FIG. 2. However, the angle remains small. As a result, the first pivoting lever 8 with its first roll 3 now has made available sufficient space for making it possible to pivot the second pivoting lever 18 in a counterclockwise direction for moving the second roll 4 into the vicinity of the third roll 5 . Since the third roll 5 has been lowered by the cylinder 7 prior to the change of operation, as a rule by 120 mm, the second roll 4 forms an open nip with the third roll 5 . Before the calender can be operated once again, the first pivoting lever is moved from the position shown in broken lines in which it rests against the stop 36 , once again back slightly in the clockwise direction in such a way that the first roll 3 is located approximately vertically above the pivot axis 9 . In this position, the first pivoting lever then rests against the second adjusting unit 35 of the second pivoting lever 18 and the openings 23 and 25 are in alignment, so that the cylinder 27 can insert a locking bolt into the aligned openings. When the cylinder 7 then moves the third roll 5 against the second roll 4 , the treatment of the fabric web 12 is then possible with the desired pressure and temperature. The arrangement is then basically mirror-metrical symmetrical relative to the arrangement illustrated in FIG.
[0042] While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A calender, particularly for webs of textile fabric, non-woven fabric or synthetic fabric, includes a frame and a first roll, a second roll and a third roll mounted on the frame. The third roll forms during operation of the calender a single nip either with the first roll or with the second roll. The first roll is movable between a work position in which it forms a nip with the third roll and a first parking position, and the second roll is movable between a work position in which it forms the nip with the third roll and a second parking position, wherein the work positions coincide and the parking position of each roll is located at such a distance from the third roll that a movement of the respectively other roll between the work position and the parking position is possible.
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FIELD OF THE INVENTION
The invention is directed to modular water retention and detention systems, the application of internal flow control systems for secondary usages and methods of assembly of such systems. The invention is also directed to modular liquid storage with controlled outflow devices and methods of assembly and application of such systems.
BACKGROUND OF THE INVENTION
Stormwater retention and detention systems (for example, also known as storage structures with controlled outflow devices) are systems typically installed underground, that are used for accommodating surface stormwater runoff by diverting and storing water to prevent pooling of water at the ground surface.
Although stormwater (or water) is being referenced generally for descriptive purposes, such liquid identification for this patent can be interchangeable with stormwater, groundwater, drinking water, irrigation water, sewerage and wastewater, or industrial process water and the associated characteristics of such specific liquid being referenced for management purposes.
Liquid retention and detention systems typically consist of a structural support component (in the form of a container or vessel), with an available storage volume and a controlled outlet flow device for metering discharge from the system. These systems are typically installed underground, but can be designed for above ground applications. The industry historically locates these systems at a lower elevation than the collection basin surface (or system) so as to take advantage of the natural potential energy (head) associated with liquid flows to eliminate the need for mechanical devices such as pumps. Stormwater systems are typically located in close vicinity of the collection area, such as under a parking lot, roadway or building to optimize the use of the land area.
Other uses of storage and controlled outflow systems involves having greywater piped into the system directly from a building, groundwater which flows into the system through the ground, and blackwater, which is pumped into the system. Greywater includes wastewater generated from domestic activities such as laundry, dishwashing, and bathing, which can be recycled on-site. Blackwater includes greywater and anything that goes down drains, including toilet water.
Water storage with controlled outflow systems are generally large structures, and thus, may be provided as modular systems that can be assembled in pieces yet meet the same intent as a singular large structure. There is a need to provide modular systems because modular systems are easier to install, allow for greater design flexibility, and have lower installation costs than nonmodular systems. This is because water storage and controlled outflow systems typically require very large storage volumes requiring heavy structural components to contain them.
It is also an advantage for the structure of a modular system to be accessible and large enough for a person to enter the system in the event servicing of a module is required.
For example, such systems are manufactured of concrete with a reinforced steel core, or interconnecting pipes or chambers constructed of metal or plastics supported by a structural stone bedding and backfill material or ponds with an open water surface.
There are various existing designs of water storage and controlled outflow systems that are known in the art. These systems, while being designed to retain and detain water and/or displace water, however, have significant disadvantages that are overcome by the presently described invention.
U.S. Pat. No. 7,621,695 to Smith et al. discloses a subsurface cubic water system having modules with pillars forming a generally cruciform cross section. U.S. Pat. No. 7,344,335 to Burkhart discloses a water retention system having modules with continuous lateral and longitudinal channels, the continuous lateral and longitudinal channels extending from one end of the system to the other allowing for unimpeded flows in any or all directions during operations.
U.S. Pat. Nos. 7,056,058, 6,779,946 and 5,810,510 to Urriola et al. disclose a transport corridor drainage system having vertical channels and no horizontal deck. The '510 patent in particular discloses an underground drainage system having channels for flow.
U.S. Pat. No. 5,249,887 to Phillips discloses an apparatus for control of liquids having modules in series; U.S. Patent Application No. 2009/0226260 to Boulton et al. discloses a method and apparatus for capturing, storing and distributing water; and U.S. Patent Application No. 2009/0279953 to Allard et al. discloses modular units having an arched opening in each of six faces, such that passages for water flow extend through the center of the structure to each opposing face.
All of these designs, however, while being designed for the storage of water and function as large holding vessels for water, do not provide a system that is designed for providing indirect flow of water internally within a system. Furthermore, these systems do not disclose the use of a modular system having beams, walls and/or weirs, the modular system allowing for a serpentine or semi-serpentine flow of water within the modules and system.
Instead, existing systems have primarily functioned as large holding vessels for water, with treatment and flow control devices occurring outside of the system structure. Existing systems do not apply and integrate the principles of treatment or internal flow control methods that affect the velocity, the potential energy (head), time attenuation (retention) flow and/or turbulence control within the system. Flow controls, such as weirs, baffles, walls, orifices, standpipes and particular intended combinations of these devices, have not been provided internally in the existing systems. Furthermore, existing systems have not used these flow controls to cause water to purposely flow indirectly internally within the system for a means of secondary application such as treatment or conditioning.
Indirect flow of water internally within storage with controlled outflow systems has advantages over existing systems. Such a design allows for water to flow through a system for a controlled period of time. Indirect flow of water internally through a storage and controlled outflow system allows for the amount of time that water is present within the system to be optimized based upon the cross-sectional area of the system (i.e., the water stays in the system for the optimal amount of time based on the cross-sectional area of the system). This allows the water to be controlled within the system and also allows for water to accumulate in the system in a controlled and systematically intended manner. This allows for optimal increased storage of water in the system and the application of controlling the flow for other purposes such as treatment, temperature regulation, flow attenuation, and other purposes for water treatment and conditioning.
Indirect flow of water internally within a retention and detention system also allows the water to be controlled within the system to achieve treatment. This allows the water to be treated or conditioned as the water flows internally within the system. A system with a purposely intended controlled indirect flow, prepares the proper environment and conditions conducive to treatment and conditioning applications. Such an intended system design can create the optimum conditions for gravity separation (allowing for both oil water separation and particle separation), neutrally buoyant materials control, trash, debris and solids control, filtering, extended detention for nutrient reduction, temperature reduction, and chemical addition. The result of such a system design may be for the use of conditioning process water or for the removal of various components (either soluble or insoluble) from the flow regime prior to the water being discharged from the system. Furthermore, indirect flow of water internally within a system has other advantages as it allows for compartmentalized flow within the system that allows for various configurations and interchangeability of applications of the system to be provided.
Additionally, indirect flow of water internally within a system may allow for systems where one compartment of the system has a solid floor, while other compartment of the system has a permeable or gravel floor, allowing water to exit the system through the bottom. This may allow for one compartment of the system to be used for water retention, while having other compartments of the system used for water treatment or other applications. In short, a system with internal indirect flow of water is desirable as it solves problems related to uncontrolled flow, such as “short circuiting”, that is common in existing systems. Moreover, internal indirect flow of water solves problems that have not been recognized in the prior art, as it requires the use of beams or other such diversionary structures that diverts the water in an indirect manner. These additional beams and/or material for diverting the water in an indirect manner involves creating systems with additional cost as extra concrete and/or other material used to divert water has to be supplied as material costs.
A system incorporating beams is also more flexible then existing systems as the beams allow for control of the water directing it into a “low flow channel” formed by the restrictive nature or the beam as a barrier and a function of the cross sectional area of the water surface area below the level of the beam. As a result of this concept, for a given period of time greater amounts of water may remain in the system with the beam design, allowing for an increased detention capacity of the system for its available storage volume. The increase in detention time is a direct result of the extended attenuation time (or flow lagging) caused by the indirect serpentine flow pattern allowing for the water to remain in the system for a longer period of time.
As none of these existing systems provide for a design having indirect flow, it is desirable to provide a design that achieves these objectives, and achieves the advantages of such a system. It is further desirable to provide a modular system that hinders the flow of water in a lateral direction, while allowing for longitudinal flow. It is further desirable to provide a modular system that hinders the flow of water in a longitudinal direction, while allowing for lateral flow.
It is also desirable to provide a system that allows for serpentine or semi-serpentine flow of water in the system and allows for control of the flow of water. It is further desirable to provide for a system that allows for internal treatment and conditioning applications of water and also allows for storage and controlled discharge of water. It is also desirable to provide a system that allows for optimal treatment of the water.
Such a water storage with controlled outflow system is novel and unobvious over the prior art. Existing systems have not recognized the problems associated with controlling “short circuiting” by establishing the indirect flow of water through a system where the level of the water is controlled by the height of the beams, walls or weirs. Such existing systems, and persons of skill in the art making such systems, would not have recognized the problem of having indirect flow as all of the existing systems simply are designed principally to store water and work to move the water through the system directly or work to retain water. Existing systems are not designed to control the flow of water in an indirect manner and to maximize treatment of the water.
Having systems with beams may allow for internal indirect flow when the level of the water is below the level (or top of the vertical height) of the beams in the system. In occasions where the level of water is higher than the top of the vertical height of the beams, such as a 2, 10, 25, 50 or even 100 year storm, it is advantageous to have beams as the system may then allow for flow of water that is unimpeded in all directions. This is advantageous over having impervious walls instead of beams, as water would not be able to pass thru the walls. However, a system incorporating impervious walls is also contemplated by the disclosure and utilized specifically when an impeded barrier is required for an application purpose.
A system that has internal indirect flow achieves both storage and controlled outflow capabilities, while allowing for treatment of water, and allowing for water to move through the system in an indirect manner, which optimizes by attenuation (or flow lagging) the amount of time the water is retained in the system. A system that achieves these objects, such as described below, is certainly desirable. Furthermore, a system that controls the velocity, the potential energy (head), time attenuation (flow lagging), flow and turbulence internally within a system is also desirable. A system that has a positive impact on the environment is also desirable.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a structural system that has indirect flow of water internally within the system. Water as discussed in this application may refer to stormwater, groundwater, drinking water, irrigation water, sewerage and wastewater, or industrial process water. Water may also refer to dirty water and water with various other materials, impurities and/or constituent characteristics such as temperature associated with the water type.
It is another object of the invention to provide a system that hinders the flow of water in a lateral direction, while allowing for the flow of water in a longitudinal direction, when the level of the water is below the level or vertical height of the beams. It is also an object of the invention to provide a system that hinders the flow of water in a longitudinal direction, while allowing for the flow of water in a lateral direction, when the level of the water is below the level or vertical height of the beams. It is an object of the invention to control the flow of water when the water is below the height of the beams.
It is another object of the invention to provide a system that allows for serpentine or semi-serpentine flow of water within the system. It is another object of the invention to provide a system where the water enters the system and progresses in a serpentine or semi-serpentine manner within and around the system. There are advantages to this design as it allows for the intended optimization of the amount of time the water is present within the system (attenuation or retention) as a function of the cross-sectional area and length of the flow channel within the system. Other advantages of this design allow for the water to be controlled and treated as it progresses within the system.
It is another object of the invention to provide a system that allows for flow control of water and for treatment of water. It is another object of the invention to provide for a system that allows for storage and controlled outflow of water. It is another object of the invention to provide a modular system made from various separate modules with different design intentions, but integral to the overall function of the management system. It is recognized that there are fluid dynamic hydraulic similarities between applications that are incorporated in and a reflection of the indirect flow capabilities of the system.
It is another object of the invention to integrate treatment and flow controls into modules which affect and take advantage of the velocity, the potential energy (head), time attenuation (retention), flow and or turbulence control of the fluid within the system.
It is another object of the invention to provide a system that has a positive impact on the environment. It is an object of the invention to provide a smaller environmental footprint than existing systems. It is an object of the invention to have more optimal use of the area of the system via its geometry than existing systems.
These and other objectives are achieved by providing a modular system for controlling a flow of water comprising: a plurality of modules, at least some of the plurality of modules comprising a horizontal deck supported by four vertical members, each of the four vertical members having a bottom edge, the plurality of modules being arranged in a grid having an x-axis and a y-axis, the plurality of modules forming: one or more longitudinal channels, the one or more longitudinal channels being defined in the direction along the y-axis of the modular system, and one or more lateral channels, the one or more lateral channels being defined in the direction along the x-axis of the modular system, wherein at least some of the plurality of modules have at least one beam extending across from one of the vertical members to another one of the vertical members of one of the modules, wherein the at least one beam extends partially upwards from the bottom edge of the one of the four vertical members towards the horizontal deck thereby creating a window.
The system may have the at least one beam direct the flow of the water when the level of the water is below the level or top of the vertical height of the beam. The vertical height of the beam extends from the bottom of the floor up towards the horizontal deck. The beam height is preferred to be approximately 12 inches from the floor or ground, when modules are preferred to be approximately 5 feet, 8 inches. However, the beam height may be adjusted in various embodiments of the invention and may be greater than or less than 12 inches in embodiments of the invention.
The system may control the flow of the water in an indirect path. An indirect path is defined as a path that is not in a straight line. Such a path may be a path that changes direction, such as allowing the water to travel in a longitudinal direction across a module and then being diverted to go in a lateral direction across another module, and vice-versa.
The system may have the plurality of the modules be stackable. Such a stackable design, allows for the system to have various levels. The system may have one, or two, or even more module levels. Such a system with more than one level is referred to a multilevel system. Stackable multilevel systems have modules that are adapted to be stacked. Such modules have structural indentations on the top of the modules that allow for the legs of other modules to be stacked upon them. Such indentations are adapted to receive the legs of other modules. In addition a lower module may or may not have an impervious deck system, an opening to allow for vertical water flow or a flow control device between layers for the intentions of controlling flow as a purposeful design.
The system may also provide for uninterrupted flow across the one or more of the longitudinal channels. The system may provide for uninterrupted flow across the one or more of the lateral channels. Uninterrupted flow is flow through a module that is not interrupted by a beam. A beam is an example of an element that causes the flow of the water to be interrupted. A wall is another example of an element that causes the flow of the water to be interrupted. Other such elements may cause the flow of the water to be interrupted.
The system may have at least some of the plurality of modules be located on the external edge of the system defining a perimeter. The system may have the perimeter of the plurality of modules be perforate. Perforate is defined as allowing for water to travel through the wall of the module via holes. The holes that allow for the wall to be perforate may be of various diameters. Typically, such holes have a diameter of approximately 1-4 inches in diameter, but are sized based on an intended controlled flow rate.
The system may have a porous surface on the bottom of the system, the plurality of modules being located on the porous surface. The porous surface may be made from gravel or other such materials that allow for the water to seep through the surface.
The system may also be located on an impermeable surface. The impermeable surface may be a material such as concrete or another material that water cannot easily travel through.
The system may have certain modules be located on a permeable surface, while other modules are located on an impermeable surface.
The system may further have at least one inlet and at least one outlet for the water to enter or exit the system in a controlled flow rate. Infiltration of the water through pervious base or perimeter materials shall be considered a type of outlet device. As would a mechanic device such as a pump or siphon device be considered a type of outlet device incorporated in the system. The system may have more than one inlet and more than one outlet. Such an inlet or outlet may be an orifice or a standpipe. An orifice is defined as a type of opening or aperture having a pipe or tubing connected to the opening allowing for the water to enter or exit the system at a purposefully designed controlled flow rate.
The system may also comprise corner modules, the corner modules each having two of the four vertical members attached to one another via walls, the walls extending from the bottom of the horizontal deck to the bottom of the vertical members and across the entire length of one edge of the horizontal deck; end modules, the end modules each having a single beam and a single wall, the single beam extending from the one of the four vertical members to another one of the four vertical members wherein the single beam extends partially upwards from the bottom edge of the one of the four vertical members towards the horizontal deck thereby creating a window, and wherein the single wall extends from the bottom of the horizontal deck to the bottom of the vertical members and across the entire length of one edge of the horizontal deck; and internal modules, the internal modules each having two beams, each of the two beams extending from the one of the four vertical members to another one of the four vertical members, wherein the two beams extend partially upwards from the bottom edge of the one of the four vertical members towards the horizontal deck thereby creating two windows.
The system may have each of its beams integrated together with their corresponding vertical members. Such an integrated structure may have the beams and corresponding vertical members be fused together as one piece. In certain embodiments, the beams and corresponding vertical members may be manufactured together as one piece during the construction of the modules. In other embodiments, the beams and corresponding vertical members may be manufactured as separate pieces which are integrated together using various industry techniques.
The system may have each of the beams direct the flow of the water when the level of the water is below the level or vertical height of each of the beams (i.e., when the water is below the maximum height of the beams). When the level of the water is greater than the beam height, then the water may travel over the beams. This typically will happen per purposeful design intent, such as in a 2, 10, 25, 50 or 100 year storm.
The system may have its walls perforated with holes. These holes may allow the water to flow through the holes. Such walls with holes that allow for the water to travel through them are defined as being perforate.
The system may have modules, which contain an inlet or an outlet, also be nonperforate. Nonperforate is defined as not letting water through. A solid wall is an example of a nonperforate wall. Nonperforate walls may exist having an opening, inlet or outlet (such as an orifice), which will allow water to enter or exit the system through the opening, inlet or outlet.
The system may have at least some of the modules have at least one such opening or orifice. The system may have modules that are nonperforate also have a weir to allow the flow of water out of the modules. The modules with nonperforate walls may be located on an impermeable surface. The system may have modules have weirs, baffles, beams, orifice holes, and particular combinations of these elements that are used to control the flow of water internally within the system. A completely enclosed module consisting of a watertight storage space (with #4 non-perforated walls and an impervious floor) may be used as an isolation chamber capable of watertight containment integrated into the system.
Other objectives of the invention are achieved by providing a module for controlling a flow of water comprising: a horizontal deck; four vertical members each having a bottom edge, the four vertical members supporting the horizontal deck and being arranged in the four corners below the horizontal deck; a first beam extending across from the one of the four vertical members to another one of the four vertical members, wherein the first beam extends partially upwards from the bottom edge of the one of the four vertical members towards the horizontal deck. The first beam is typically provided as having its upper surface be parallel to the horizontal deck. In other embodiments, the first beam may have its upper surface be approximately parallel to the horizontal deck and/or may have its upper surface be angled with respect to the horizontal deck.
The module may have the first beam form a window between the top of the beam and the bottom of the horizontal deck. Such a window may have various shapes. However, the window does not involve having the module have more concrete above the beam than the beam itself. The window is different than a weir, as the window is formed based upon the beam, not based upon cutting a hole in a solid wall. A hole is a solid wall is defined as being an opening. A window, is not simply an opening, but rather is the open area from the top of the beam to approximately the bottom of the horizontal deck. The window does not extend all the way up to the bottom of the horizontal deck. There is a structural section a few inches wide between the deck and the top of the window opening.
The module may have the first beam direct the flow of the water when the water is below the top of the vertical height of the first beam. The first beam may allow the water to flow indirectly through the module and/or system.
The module may have one of the vertical members be attached to another one of the vertical members via a first wall, the first wall extending from the bottom of the horizontal deck to the bottom of the vertical member and across the entire length of one edge of the horizontal deck. The module may have the wall have perforated holes.
The module may have a second beam extending across from the one of the four vertical members to another one of the four vertical members. The second beam may extend partially upwards from the bottom edge of the one of the four vertical members towards the horizontal deck.
The second beam may form a window between the top of the second beam and the bottom of the horizontal deck. The second beam may direct the flow of the water when the level of the water is below the top of the vertical height of the second beam (i.e., below the beam height).
The module may have the first beam be integrated together with two of the four vertical members it extends across. The module may have the second beam be integrated together with two of the four vertical members it extends across. The beam may be manufactured with the vertical members as one piece or may be separate pieces that are connected together using conventional techniques known in the industry. The module may be stackable. Such modules have indentations on the top of the modules that allow for the legs of other modules to be stacked upon them. The module may form at least one channel through the module. The module may have a structural component with a storage capacity. The module may made of a steel core within the module and be reinforced by concrete.
Other objectives of the invention are achieved by providing a method for controlling a flow of water in a modular system comprising: providing a plurality of modules, each of the plurality of modules comprising: a horizontal deck supported by four vertical members, the plurality of modules being arranged in a grid having an x-axis and a y-axis, the plurality of modules forming one or more longitudinal channels, the one or more longitudinal channels being defined in the direction along the y-axis of the modular system, one or more lateral channels, the one or more lateral channels being defined in the direction along the x-axis of the modular system; and wherein the at least some of the plurality of modules have at least one beam extending from the one of the four vertical members to another one of the four vertical members, wherein the at least one beam extends partially upwards from the bottom edge of the one of the four vertical members towards the horizontal deck thereby creating a window; inserting the water into the plurality of modules by natural or artificial means, wherein the water is directed through the system by the at least one beam in the plurality of modules, wherein the at least one beam directs the flow of the water when the water is below the level or vertical height of the beam.
The water in the method may be routed through the modular water system in a serpentine or semi-serpentine manner. A serpentine or semi-serpentine manner involves the water flowing in a snakelike fashion where the water may travel through various modules in one direction and then turn and travel in a different direction which may be different and/or opposite to the original direction. Travelling in a serpentine or semi-serpentine manner involves having the water change directions at least once as it travels through the system.
In other embodiments, the water may travel in a single or double row system (such that the beam hinders movement of the water laterally while allowing it to move longitudinally). In these embodiments, the water may not move in a serpentine or semi-serpentine manner.
Other objectives of the invention are achieved by providing a modular system for controlling a flow of water comprising: a plurality of modules, at least some of the plurality of modules comprising a horizontal deck supported by four vertical members, the plurality of modules being arranged in a grid having an x-axis and a y-axis, the plurality of modules forming: one or more longitudinal channels, the one or more longitudinal channels being defined in the direction along the y-axis of the modular system, and one or more lateral channels, the one or more lateral channels being defined in the direction along the x-axis of the modular system, wherein the modular system provides for serpentine flow through the longitudinal and lateral channels.
The modular system may provide for serpentine flow because of a plurality of horizontal beams that direct the flow of the water when the level of the water is below the top of the vertical height of each of the plurality of horizontal beams. When the water flows into the beams, the water is diverted into a different direction.
The modular system may have various internal flow controls, such as weirs, baffles, walls, beams, orifice holes, and particular combinations of these devices. Such internal flow controls are used to control the internal flow of the system so it has indirect flow.
Other objects of the invention and its particular features and advantages will become more apparent from consideration of the following drawings and accompanying detailed description. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a grid view of an embodiment of the system;
FIG. 2 is a perspective view of a module of the system of FIG. 1 ;
FIG. 2A is a top view of the module of FIG. 2 ;
FIG. 2B is a cross section view of FIG. 2 taken along axis A-A;
FIG. 2C is a cross section view of FIG. 2 taken along axis B-B;
FIG. 3 is a perspective view of a module of the system of FIG. 1 ;
FIG. 3A is a top view of the module of FIG. 3 ;
FIG. 3B is a cross section view of FIG. 3 taken along axis A-A;
FIG. 3C is a cross section view of FIG. 3 taken along axis B-B;
FIG. 4 is a perspective view of a module of the system of FIG. 1 ;
FIG. 4A is a top view of the module of FIG. 4 ;
FIG. 4B is a cross section view of FIG. 4 taken along axis A-A;
FIG. 4C is a cross section view of FIG. 4 taken along axis B-B;
FIG. 5 is a perspective view of a module of the system of FIG. 1 ;
FIG. 5A is a top view of the module of FIG. 5 ;
FIG. 5B is a cross section view of FIG. 5 taken along axis A-A;
FIG. 5C is a cross section view of FIG. 5 taken along axis B-B;
FIG. 6 is a perspective view of a module of the system of FIG. 1 ;
FIG. 6A is a top view of the module of FIG. 6 ;
FIG. 6B is a cross section view of FIG. 6 taken along axis A-A;
FIG. 6C is a cross section view of FIG. 6 taken along axis B-B;
FIG. 7 is a perspective view of a module of the system of FIG. 1 ;
FIG. 7A is a top view of the module of FIG. 7 ;
FIG. 7B is a cross section view of FIG. 7 taken along axis A-A;
FIG. 7C is a cross section view of FIG. 7 taken along axis B-B;
FIG. 8 is a perspective view of a module of the system of FIG. 1 ;
FIG. 8A is a top view of the module of FIG. 8 ;
FIG. 8B is a cross section view of FIG. 8 taken along axis A-A;
FIG. 8C is a cross section view of FIG. 8 taken along axis B-B;
FIG. 9 is a perspective view of another embodiment of the system;
FIG. 9A is a side view of the system shown in FIG. 9 ;
FIG. 10 is a grid view of the top portion of the system shown in FIG. 9 ;
FIG. 10A is a grid view of the bottom portion of the system shown in FIG. 9 ;
FIG. 11 is a perspective view of a module of the system of FIG. 1 ;
FIG. 11A is a top view of the module of FIG. 11 ;
FIG. 11B is a cross section view of FIG. 11 along axis A-A;
FIG. 11C is a cross section view of FIG. 11 along axis B-B;
FIG. 12 is a perspective view of a module of the system of FIG. 1 ;
FIG. 12A is a top view of the module of FIG. 12 ;
FIG. 12B is a cross section view of FIG. 12 along axis A-A;
FIG. 12C is a cross section view of FIG. 12 along axis B-B;
FIG. 13 is a perspective view of a module of the system of FIG. 1 ;
FIG. 13A is a top view of the module of FIG. 13 ;
FIG. 13B is a cross section view of FIG. 13 along axis A-A;
FIG. 13C is a cross section view of FIG. 13 along axis B-B;
FIG. 14 is a perspective view of a module of the system of FIG. 9 ;
FIG. 14A is a top view of the module of FIG. 14 ;
FIG. 14B is a cross section view of FIG. 14 along axis A-A;
FIG. 14C is a cross section view of FIG. 14 along axis B-B;
FIG. 15 is a perspective view of a module of the system of FIG. 9 ;
FIG. 15A is a top view of the module of FIG. 15 ;
FIG. 15B is a cross section view of FIG. 15 along axis A-A;
FIG. 15C is a cross section view of FIG. 15 along axis B-B;
FIG. 16 is a grid view of another embodiment of the system; and
FIG. 17 is a perspective view of a module of the system of the invention;
FIG. 18 . is a perspective view of a module of the system of the invention;
FIG. 19 is a perspective view of a module of the system of the invention;
FIG. 20 is a perspective view of a module of the system of the invention;
FIG. 21 is a perspective view of a module of the system of the invention; and
FIG. 22 is a perspective view of a module of the system of the invention;
FIG. 23 is a perspective view of a module of the system of the invention;
FIG. 24 is a perspective view of a module of the system of the invention;
FIG. 25 is a perspective view of a module of the system of the invention;
FIG. 26 is a perspective view of a module of the system of the invention;
FIG. 27 is a perspective view of a module of the system of the invention; and
FIG. 28 is a perspective view of a module of the system of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , storage and control outflow system 1000 is shown. System 1000 is made of various modules and is an example of an embodiment of the system disclosed by the present invention. System 1000 is shown having three inlets 110 and one outlet 120 . However, there may be more inlets or less inlets 110 and outlets 120 for system 1000 than shown in FIG. 1 . System 1000 has a legend on the left of the system showing what FIG. 1 and FIGS. 10 and 10A mean by a perforated wall, 12″ beam wall, window, solid wall and weir. System 1000 also has an x-axis as shown (lateral direction) and y-axis (longitudinal direction), which shows the flow of the water through the system in lateral and longitudinal channels, respectively.
System 1000 also has arrows through the system that show the direction of the flow of water within the system. This is an example of a serpentine flow of the water as the arrows show that the water travels in a snakelike manner through the system, where the flow of water changes direction at least once. System 1000 also reduces the turbulence the water as the water changes direction.
System 1000 achieves the advantages of the present invention. Such advantages involve achieving indirect flow of the water internally within system 1000 , which is advantageous over existing systems. System 1000 allows for the water to flow through system 1000 for a controlled period of time. System 1000 may allow water to be treated by a treatment system and method as the water flows within system 1000 . Such a treatment system may filter the water, removing various components of the water from the system prior to the water exiting the system. Such a treatment system may be present in various modules of system 1000 .
System 1000 also allows for the optimization of the amount of time that the water is present within system 1000 based upon the cross-sectional area of the system. This allows for the water to accumulate in system 1000 in a controlled and systematic manner. This allows for increased storage of the water in system 1000 . Moreover, greater amounts of the water may be in system 1000 at a given time, as it has 12 inch beams, allowing for increased storage and retention capacity of the system per its cross-sectional area. If the beam height is increased, the system is able to retain more water per cross-sectional area at a given time.
Dimensions of system 1000 are shown as having 12 inch beams (12 inches being the beam height); however, beams with other heights may be used in the system, such as having beams that have a height of greater than 12 inches. System 1000 is made of various modules. Modules typically are approximately 8 feet wide and 8 feet deep and have a height of 5 feet 8 inches when employing 12 inch beams. The beam height to height of the module ratio thus is typically 1:8.5. However, the ratio of height of the module to beam height may vary depending upon the system and can range from 1:3-1:20. Modules can also have a height that ranges from 3 feet to a height of 12 feet. Modules less than 3 feet are difficult to work with as it is difficult for a man to enter a smaller module to service it.
Furthermore, modules typically have the ability to support 10,000 to 14,000 pounds of weight. However, modules may support additional weight based on materials used, such as having a steel frame internal to the concrete outer shell. Modules may be made of other materials known in the art, and may be made of materials that are more expensive and have greater load bearing capabilities, if desired.
System 1000 has modules having two perforated walls, such as module 300 ; modules having one perforated wall and one beam, such as module 400 and module 800 ; and modules having two beams, such as module 200 .
System 1000 also has modules that have two or more solid walls, such as module 600 , module 700 and module 1100 (with 3 solid walls); and modules that have two solid walls and a weir, such as module 500 . System 1000 may be located on a solid surface, which is impermeable. System 1000 may be located on a permeable surface, such as crushed granite. The system may have certain modules located on a permeable surface and may have other modules located on a solid impermeable surface such as concrete. Preferably, modules 500 , 600 , 700 and 1100 are located on an impermeable surface. These modules typically have a floor which is impermeable. Preferably, modules 200 , 300 , 400 , 800 , and 1200 are located on a permeable surface. However, various modules can be arranged on various surfaces and or materials.
FIG. 2 shows one type of module in system 1000 . Module 200 is shown having four legs 220 , 225 , 230 and 235 . Four legs 220 , 225 , 230 and 235 support horizontal deck 210 . Each of the four legs 220 , 225 , 230 and 235 has a bottom edge.
Legs 220 and 225 are connected together via beam 240 . Legs 230 and 235 are connected together via beam 250 . Beams 240 and 250 are preferably about 12 inches in height from the bottom edge to the top of the beam. The height of the module 200 is preferably 5 feet 8 inches.
Beams 240 and 250 , however, may vary in height to be more or less than 12 inches in height from the bottom edge to the top of the beam. Beams 240 and 250 are used to control the flow of the water so that it moves in an indirect manner within the system. Beams 240 and 250 are also used, to allow the water to flow around the system in a serpentine or semi-serpentine manner.
FIG. 2 also shows window 245 formed in the space between beam 240 and horizontal deck 210 and window 255 formed in the space between beam 250 and horizontal deck 210 . Module 200 also has a channel which extends through the module from 265 to 275 . Channel 265 / 275 allows for the water to flow uninterrupted within module 200 . The height of the channel 265 / 275 is preferably 4 feet 6 inches when using a module with a height of 5 feet 8 inches; however this may vary in various embodiments. The ratio of the height of the channel to the height of the module ranges from 1:2 to 4:5. Such dimensions are applicable to all modules described in the system.
Moreover, channel height may vary within various modules as the height of the floor may vary. However, typically the channel has a standard cross-sectional area through the channel. Such a cross-sectional area is approximately the same within various modules in a system.
FIGS. 2A , 2 B and 2 C show various views of module 200 . FIG. 2A provides a top view where axes A-A and B-B are shown. FIG. 2B is a view across axis A-A where channel 275 / 265 is shown. Legs 225 and 230 are also shown in this view as well as beam 240 and beam 250 and window 245 and window 255 . FIG. 2C is a view across axis B-B where beam 240 and window 245 are shown as well as legs 220 and 225 .
FIG. 3 shows another type of module in system 1000 . Module 300 is shown having four legs 320 , 325 , 330 and 335 . Four legs 320 , 325 , 330 and 335 support horizontal deck 310 . Each of the four legs 320 , 325 , 330 and 335 has a bottom edge.
Legs 325 and 330 are connected together via wall 370 . Legs 330 and 335 are connected together via wall 350 . Wall 370 and wall 350 are shown as having perforations 380 . Perforations 380 allow for the water to exit the system. Perforations may be holes that have a minimum diameter of one inch. The holes may be larger than one inch; however, holes and perforations are smaller than the openings defined in this invention.
FIG. 3 also shows channels 345 and 365 formed in the space between the bottom edges of the four legs to the underside of horizontal deck 310 . Channels 345 and 365 allow for the water or fluid to flow through module 300 . As shown the entrance way of channel 345 , there is a height of the channel from the bottom of the floor to the underside of the deck. However, the underside of the deck may have a greater height to the floor in the middle of the module than the height of bottom of the floor to the underside of the deck in the channel opening.
FIGS. 3A , 3 B and 3 C show various views of module 300 . FIG. 3A provides a top view where axes A-A and B-B are shown. FIG. 3B is a view across axis A-A where wall 370 is shown. Legs 325 and 330 are also shown in this view as well as channel 345 and wall 350 . FIG. 3C is a view across axis B-B where channel 345 is shown.
FIG. 4 shows another type of module in system 1000 . Module 400 is shown having four legs 420 , 425 , 430 and 435 . The four legs 420 , 425 , 430 and 435 each support horizontal deck 410 . Each of the four legs 420 , 425 , 430 and 435 has a bottom edge.
Legs 420 and 435 are connected together via beam 460 . Legs 425 and 430 (hidden from FIG. 4 ) are connected together via wall 470 . Beam 460 is preferably about 12 inches in height or greater from the bottom edge to the top of the beam. Beam 460 is used to control the flow of the water so that it moves in an indirect manner within the system. Beam 460 is also used to allow the water to flow around the system in a serpentine manner. Wall 470 has perforations 480 . Perforations 480 may allow for the water to exit the system. Perforations 480 typically have a diameter of a few inches.
FIG. 4 also shows window 465 formed in the space between beam 460 and horizontal deck 410 . Module 400 also has a channel 445 which extends through the module from 445 to 455 . The channel 445 / 455 allows for the water to flow uninterrupted through module 400 .
FIGS. 4A , 4 B and 4 C show various views of module 400 . FIG. 4A provides a top view where axes A-A and B-B are shown. FIG. 4B is a view across axis A-A where wall 470 is shown. Legs 425 and 430 are also shown in this view. FIG. 4C is a view across axis B-B where channel 445 / 455 is shown.
FIG. 5 shows another type of module in system 1000 . Module 500 is shown having four legs 520 , 525 , 530 and 535 . The four legs 520 , 525 , 530 and 535 each support horizontal deck 510 . Each of the four legs 520 , 525 , 530 and 535 has a bottom edge. Each of the four legs 520 , 525 , 530 and 535 is supported by floor 590 . Floor 590 is shown as being a solid impermeable floor.
Legs 520 and 525 are connected together via wall 540 . Legs 530 and 535 are connected together via wall 550 . Legs 520 and 535 are connected together via wall 560 . Walls 540 , 550 and 560 are shown as solid walls.
FIG. 5 also shows channel 575 formed in the space between floor 590 and the underside of horizontal deck 510 . Channel 575 allows for the water to flow through the module. FIG. 5 also has either weir 580 or opening 585 . Opening 585 allow an inlet or outlet to be connected to the module (such as inlet 110 or outlet 120 shown in FIG. 1 ). If a weir 585 is provided, an inlet or outlet is typically not attached.
FIGS. 5A , 5 B and 5 C show various views of module 500 . FIG. 5A provides a top view where axes A-A and B-B are shown. FIG. 5B is a view across axis A-A where channel 575 is shown. Legs 525 and 530 are also shown in this view. FIG. 5C is a view across axis B-B where wall 540 is shown.
FIG. 6 shows another type of module in system 1000 . Module 600 is shown having four legs 620 , 625 , 630 and 635 . The four legs 620 , 625 , 630 and 635 each support horizontal deck 610 . Each of the four legs 620 , 625 , 630 and 635 has a bottom edge. These legs are supported on a floor 690 . Preferably, floor 690 is impermeable.
Legs 620 and 625 are connected together via wall 640 . Legs 630 and 635 are connected together via wall 650 . Walls 640 and 650 are shown as solid walls. Wall 640 may have an opening 685 attached to the wall. This opening 685 may allow an inlet or outlet to be connected to the module (such as inlet 110 shown in FIG. 1 ). Such an opening 685 is optional to module 600 .
FIG. 6 also shows channel 665 formed in the space between the floor 690 and the underside of horizontal deck 610 . FIG. 6 also shows channel 675 formed in the space between floor 690 and the underside of horizontal deck 610 . The channel height may vary in the module shown in FIG. 6 . Channel 675 allows for the water to flow through the module and is connected to channel 665 forming channel 665 / 675 .
FIGS. 6A , 6 B and 6 C show various views of module 600 . FIG. 6A provides a top view where axes A-A and B-B are shown. FIG. 6B is a view across axis A-A where channel 665 / 675 is shown. Legs 625 and 630 are also shown in this view. FIG. 6C is a view across axis B-B where wall 640 is shown.
FIG. 7 shows another type of module in system 1000 . Module 700 is shown having four legs 720 , 725 , 730 and 735 . The four legs 720 , 725 , 730 and 735 each support horizontal deck 710 . Each of the four legs 720 , 725 , 730 and 735 has a bottom edge. These legs are supported on a floor 790 . Preferably, floor 790 is impermeable.
Legs 725 and 730 are connected together via wall 770 . Legs 730 and 735 are connected together via wall 750 . Walls 770 and 750 are shown as solid walls. Wall 750 may have an opening 785 . This opening 785 may allow an inlet or outlet to be connected to the module (such as inlet 110 shown in FIG. 1 ). Such an opening 785 is optional to module 700 ,
FIG. 7 also shows channel 765 formed in the space between floor 790 and the underside of horizontal deck 710 . Channel 765 allows for the water to flow through module 700 . FIG. 7 also shows channel 745 formed in the space between floor 790 and the underside of horizontal deck 710 . Channel 745 allows for the water to flow through module 700 and is connected to channel 765 . Channels 745 and 765 may have various heights as the channel height in the center of module 700 is greater than the channel height as the edge of module 700 .
FIGS. 7A , 7 B and 7 C show various views of module 700 . FIG. 7A provides a top view where axes A-A and B-B are shown. FIG. 7B is a view across axis A-A where wall 770 is shown. Legs 725 and 730 are also shown in this view. FIG. 7C is a view across axis B-B where channel 745 is shown.
FIG. 8 shows another type of module in system 1000 . Module 800 is shown having four legs 820 , 825 , 830 and 835 . The four legs 820 , 825 , 830 and 835 each support horizontal deck 810 . Each of the four legs 820 , 825 , 830 and 835 has a bottom edge.
Legs 820 and 825 are connected together via beam 840 . Legs 820 and 835 are connected together via wall 860 . Wall 860 is shown as a wall with perforations 880 . Window 845 is also shown between the underside of horizontal deck 810 and the top of beam 840 .
FIG. 8 also shows channel 875 formed in the space between bottom edges of the leg 825 and 830 to the underside of horizontal deck 810 . Channel 875 allows for the water to flow through module 800 . FIG. 8 also shows channel 855 formed in the space between bottom edges of the leg 830 and 835 to the underside of horizontal deck 810 . Channel 855 allows for the water to flow through the module and is connected to channel 875 .
FIGS. 8A , 8 B and 8 C show various views of module 800 . FIG. 8A provides a top view where axes A-A and B-B are shown. FIG. 8B is a view across axis A-A where channel 875 is shown. Legs 825 and 830 are also shown in this view. FIG. 8C is a view across axis B-B where beam 840 and window 845 are shown.
FIG. 11 shows another type of module in system 1000 . Module 1100 is shown having four legs 1120 , 1125 , 1130 and 1135 . Each of the four legs 1120 , 1125 , 1130 and 1135 support horizontal deck 1110 . Each of the four legs 1120 , 1125 , 1130 and 1135 has a bottom edge. Furthermore, module 1100 has floor 1190 .
Legs 1120 and 1125 are connected together via wall 1140 . Legs 1125 and 1130 are connected together via wall 1170 . Legs 1120 and 1135 are connected together via wall 1160 . Walls 1140 , 1160 and 1170 are shown as solid walls. Wall 1160 has an opening 1180 , which allows for an inlet or outlet to be connected to module 1100 . FIG. 11 also shows channel 1155 formed in the space between floor 1190 and the underside of horizontal deck 1110 . Channel 1155 allows for the water to flow through the module. The water may flow through and enter/exit the module via opening 1185 or channel 1155 .
FIGS. 11A , 11 B and 11 C show various views of module 1100 . FIG. 11A provides a top view where axes A-A and B-B are shown. FIG. 11B is a view across axis A-A where wall 1170 is shown. Legs 1125 and 1130 are also shown in this view. FIG. 11C is a view across axis B-B where wall 1140 is shown.
FIG. 12 shows a type of module in system 1000 . Module 1200 is shown having four legs 1220 , 1225 , 1230 and 1235 . The four legs 1220 , 1225 , 1230 and 1235 support horizontal deck 1210 . Each of the four legs 1220 , 1225 , 1230 and 1235 has a bottom edge.
Legs 1220 and 1225 are connected together via wall 1240 . Legs 1220 and 1235 are connected together via wall 1260 . Walls 1240 and 1260 are shown having perforations 1280 . Legs 1225 and 1230 are connected together via wall 1270 . Wall 1270 is shown as being a solid wall. In certain embodiments solid wall 1270 may be replaced by a beam and a window. Wall 1260 also may have opening 1295 allowing for an inlet or outlet to be connected to module 1200 . Such an opening 1295 is optional to module 1200 .
FIG. 12 also shows channel 1255 formed in the space between bottom edges of the leg 1230 and 1235 to the underside of horizontal deck 1210 . Channel 1255 allows for the water to flow through the module.
FIGS. 12A , 12 B and 12 C show various views of module 1200 . FIG. 12A provides a top view where axes A-A and B-B are shown. FIG. 12B is a view across axis A-A where wall 1270 is shown. Legs 1225 and 1230 are also shown in this view. FIG. 12C is a view across axis B-B where wall 1240 is shown.
FIGS. 9 and 9A each show another embodiment of the invention, system 900 . System 900 is made of various modules, and may have some of the modules previously described. System 900 is shown having an inlet 910 and having two stacks of modules, upper stack 950 and lower stack 960 . Various modules previously described (modules 200 , 300 , 400 , 500 , 600 and 800 ) may be used in system 900 . Furthermore, additional modules may also be used in system 900 .
FIGS. 10 and 10A show a schematic or grid view of system 900 . FIG. 10 is a view of upper stack 950 . FIG. 10A is a view of lower stack 960 . Various modules previously described may be used for upper stack 950 and lower stack 960 . Upper stack 950 and lower stack 960 work together as a coordinated multilayer system. Inlet/outlet 595 is shown in FIG. 10 . Other inlets and/or outlets may be incorporated into system 900 .
FIG. 13 shows a type of module in system 900 . Module 1300 is shown having four legs 1320 , 1325 , 1330 and 1335 . The four legs 1320 , 1325 , 1330 and 1335 support horizontal deck 1310 . Each of the four legs 1320 , 1325 , 1330 and 1335 has a bottom edge.
Legs 1325 and 1330 are connected together via wall 1370 . Wall 1370 is shown as a solid wall. Legs 1330 and 1335 are connected together via wall 1350 . Wall 1350 is shown having perforations 1380 .
FIG. 13 also shows channel 1345 formed in the space between bottom edges of the leg 1320 and 1325 to the underside of horizontal deck 1310 . Channel 1345 allows for the water to flow through the module. FIG. 13 also shows channel 1365 formed in the space between bottom edges of the leg 1320 and 1335 to the underside of horizontal deck 1310 . Channel 1365 allows for the water to flow through the module and is connected to channel 1345 .
FIGS. 13A , 13 B and 13 C show various views of module 1300 . FIG. 13A provides a top view where axes A-A and B-B are shown. FIG. 13B is a view across axis A-A where wall 1370 is shown. Legs 1325 and 1330 are also shown in this view. FIG. 13C is a view across axis B-B where channel 1345 is shown.
FIG. 14 shows another type of module in system 900 . Module 1400 is shown having four legs 1420 , 1425 , 1430 and 1435 . The four legs 1420 , 1425 , 1430 and 1435 support horizontal deck 1410 . Each of the four legs 1420 , 1425 , 1430 and 1435 has a bottom edge.
Legs 1425 and 1430 are connected together via beam 1470 . Window 1475 is shown between the underside of horizontal deck 1410 and the top of beam 1470 .
FIG. 14 also shows channel 1445 formed in the space between the underside of horizontal deck 1410 and the floor and between leg 1420 and leg 1425 . Channel 1445 allows for the water to flow through the module. FIG. 14 also shows channel 1455 formed in the space between the underside of horizontal deck 1410 and the floor and between leg 1430 and leg 1435 . Channel 1455 allows for the water to flow through the module and is connected to channel 1445 . FIG. 14 also shown channel 1465 formed in the space between the underside of horizontal deck 1410 and the floor and between leg 1420 and leg 1435 . Channel 1465 allows for the water to flow through the module and is connected to channel 1445 and channel 1455 .
FIGS. 14A , 14 B and 14 C show various views of module 1400 . FIG. 14A provides a top view where axes A-A and B-B are shown. FIG. 14B is a view across axis A-A where beam 1470 and window 1475 are shown. Legs 1425 and 1430 are also shown in this view. FIG. 14C is a view across axis B-B where channel 1445 / 1465 is shown.
FIG. 15 shows another type of module in system 900 . Module 1500 is shown having four legs 1520 , 1525 , 1530 and 1535 . The four legs 1520 , 1525 , 1530 and 1535 support horizontal deck 1510 . Each of the four legs 1520 , 1525 , 1530 and 1535 has a bottom edge.
Legs 1520 and 1535 are connected together via wall 1560 . Wall 1560 is shown as having perforations 1580 .
FIG. 15 also shows channel 1545 formed in the space between bottom edges of the leg 1520 and 1525 to the underside of horizontal deck 1510 . Channel 1545 allows for the water to flow through the module. FIG. 15 also shows channel 1575 formed in the space between bottom edges of the leg 1525 and 1530 to the underside of horizontal deck 1510 . Channel 1575 allows for the water to flow through the module and is connected to channel 1545 . FIG. 15 also shows channel 1555 formed in the space between bottom edges of the leg 1530 and 1535 to the underside of horizontal deck 1510 . Channel 1555 allows for the water to flow through the module and is connected to channel 1545 and 1575 .
FIGS. 15A , 15 B and 15 C show various views of module 1500 . FIG. 15A provides a top view where axes A-A and B-B are shown. FIG. 15B is a view across axis A-A where channel 1575 is shown. Legs 1525 and 1530 are also shown in this view. FIG. 15C is a view across axis B-B where channel 1545 / 1555 is shown.
FIG. 16 shows a storage and controlled outflow system 1600 . System 1600 is made of various modules. System 1600 is shown having three inlets 110 and one outlet 120 . However, there may be more inlets or less inlets 110 and outlets 120 for system 1600 than shown in FIG. 16 . The modules previously described (modules 200 , 300 , 400 , 500 , 600 , 700 , 800 , 1100 and 1200 ) are shown as being used for system 1600 . Furthermore, system 1600 is shown having a liner 1650 . This liner may be non-perforate and may not allow (i.e. prevent or stop) the water to exit the system through liner 1650 . This acts to retain the water in the system. The liner may increase the amount of the water in the system, until it exits through various openings in the system.
The modules of various embodiments of the invention are preferably made of concrete, however they may be made of other material, such as cement, gravel, aggregate (such as crushed rock or gravel made of limestone or granite, plus a fine aggregate such as sand). Such materials should be able to support a load. The modules preferably have a reinforced steel frame within the modules for support, and an outer concrete shell. Such a steel frame allows the modules strength to support a load.
The modules may have a man hole located at the top of the modules. The man hole allows maintenance people to enter the module in the event trash enters the module, and/or the modules need to be cleaned. In certain embodiments, the openings the modules are large enough to allow a man to enter the modules.
The modules may have an outlet weir with trash rack installed across the weir opening. The modules may have baffles located within the modules. The modules may have other such advantages that allow for flow control in the module.
Such flow control may also allow the modules to have a sump feature. The modules may also have an optional orifice located on various walls of the modules. The optional orifice may be larger than the perforations shown in the modules, which typically have a diameter of only a few inches. The orifice is typically 24 inches in diameter, however, the orifice described may be larger or smaller than 24 inches depending upon the size of the module.
Other objectives of the modular system may be met by providing various other modules to assist in flow control of the water within a system. These modules may have water treatment advantages that allow for the water to be treated as it flows through the system.
These treatment modules may have perforated walls and beams. The treatment modules may have an outlet hole or backwall. The outlet hole on backwall may be 24 inches. The modules may have a 12 inch sump height. The treatment modules may have a filter media to treat the water. The modules may have a trash rack and weir system to control the flow of water. The modules may have filtering, oil/water separation, TSS (total suspended solids), removal, trash and debris removal, nutrient reduction, soluble chemical capture, all dependent on placement of weirs, walls, baffles, beams, and internal outlet control devices. The treatment modules may have filtering, temperature regulation, oxygenation, introduction of chemical treatment, and sterilization capabilities all related to compartmentalized and indirect flow systems).
The treatment modules may have filter media within the modules. The modules may have an underflow collection system within the modules. The treatment modules may have an outlet pipe that is connected to the filter media. The treatment modules may be located where the modules have a floor such as modules 500 , 600 and 1100 . The treatment modules may also be located where the floor of the system is made of stone.
The treatment modules may be arranged in a flow pattern that is serpentine. This allows the water to stay in the system for the optimal amount of time for treatment before exiting the system. This allows for optimal treatment of the water.
FIG. 17 shows a type of treatment module in the modular system of the invention. Module 1700 is shown having four legs 1720 , 1725 , 1730 and 1735 . The four legs 1720 , 1725 , 1730 and 1735 support horizontal deck 1710 . Each of the four legs 1720 , 1725 , 1730 and 1735 has a bottom edge.
Legs 1720 and 1725 are connected together via a wall 1740 . Legs 1720 and 1735 are connected together via wall 1760 . Baffle 1765 is shown beneath wall 1760 . The space between legs 1725 and 1730 forms channel 1775 . Wall 1750 is shown as being a solid wall between legs 1730 and 1735 . The module 1700 is also shown having a floor 1790 .
FIG. 18 shows a type of treatment module in the modular system of the invention. Module 1800 is shown having four legs 1820 , 1825 , 1830 and 1835 . The four legs 1820 , 1825 , 1830 and 1835 support horizontal deck 1810 . Each of the four legs 1820 , 1825 , 1830 and 1835 has a bottom edge. Horizontal deck 1810 has riser 1805 . Riser 1805 may be 24 inches in height. Riser 1805 may be more or less than 24 inches in height.
Legs 1820 and 1825 are connected together to form a channel 1845 . Legs 1820 and 1835 are connected together via wall 1860 . Legs 1825 and 1830 are connected together to form a low wall 1870 . An opening 1875 is shown above low wall 1870 . The module 1800 is also shown having a floor 1890 .
FIG. 19 shows a type of treatment module in the modular system of the invention. Module 1900 is shown having four legs 1920 , 1925 , 1930 and 1935 . The four legs 1920 , 1925 , 1930 and 1935 support horizontal deck 1910 . Each of the four legs 1920 , 1925 , 1930 and 1935 has a bottom edge. Horizontal deck 1910 has riser 1905 . Riser 1905 may be 24 inches in height. Riser 1905 may be more or less than 24 inches in height.
Legs 1920 and 1925 are connected together via low wall 1940 . Window 1945 is shown above low wall 1940 . Legs 1925 and 1930 are connected to form a wall 1970 . Opening 1975 is shown in the wall connected to an outlet 1915 . Legs 1930 and 1935 are connected together to form a wall 1950 . Legs 1920 and 1935 are connected together via channel 1965 . The module 1900 is also shown having a floor 1990 .
FIG. 20 shows a type of treatment module in the modular system of the invention. Module 2000 is shown having four legs 2020 , 2025 , 2030 and 2035 . The four legs 2020 , 2025 , 2030 and 2035 support horizontal deck 2010 . Each of the four legs 2020 , 2025 , 2030 and 2035 has a bottom edge. Horizontal deck 2010 has riser 2005 . Riser 2005 may be 24 inches in height. Riser 2005 may be more or less than 24 inches in height. Inside module 2000 is filter media 2030 and outlet pipe 2085 . Legs 2030 and 2035 are connected by wall 2050 .
FIG. 21 shows a type of treatment module in the modular system of the invention. Module 2100 is shown having four corners 2120 , 2125 , 2130 and 2135 . Module 2100 is actually made up of two separate modules 2110 and 2115 . Located inside module 2100 is filter media 2130 and output pipe 2180 . Output pipe 2180 is connected to underflow collection system 2185 . Filter media 2130 is used to filter and/or treat water.
FIG. 22 shows a type of treatment module in the modular system of the invention. Module 2200 is shown having four legs 2220 , 2225 , 2230 and 2235 . The four legs 2220 , 2225 , 2230 and 2235 support horizontal deck 2210 . Each of the four legs 2220 , 2225 , 2230 and 2235 has a bottom edge. Horizontal deck 2210 has riser 2205 . Riser 2205 may be 24 inches in height.
Legs 2220 and 2225 are connected together to form a channel 2245 . Legs 2220 and 2235 are connected together via wall 2260 . Weir 2265 is above wall 2260 . Trash rack 2262 is shown installed in weir 2265 . Legs 2225 and 2230 are connected together via wall 2270 . Module 2200 is also shown having a floor 2290 .
Various embodiments of the system may be arranged as either sealed or non-sealed systems. Sealed systems may have a non-perforate liner or another such barrier that will prevent the water from leaving the system. Sealed systems typically only allow water to leave the system via inlets and outlets.
Non-sealed systems do not have a non-perforate liner. Water may leave the non-sealed systems via perforations in the walls of the perimeter modules and the outlets of the system. Furthermore, in a non-sealed system, water may leave through the floor of the system.
Other embodiments of the invention involve having stackable systems with a drop outlet structure with control orifice. The drop outlet structure is for a multilayer or stackable system (as shown in FIGS. 9 , 9 A, 10 and 10 A), where the water drops from a module in the upper stack to a module in the lower stack. In such a system, the modules may be arranged stacked on a stone base. Such a system may have an outlet control rise with orifice holes and an overflow weir. Such a system may have various weirs located in the system to control flow in the system for accumulation of water.
FIGS. 2B , 2 C, 3 B, 3 C, 4 B, 4 C, 5 B, 5 C, 6 B, 6 C, 7 B, 7 C, 8 B, 8 C, 11 B, 11 C, 12 B, 12 C, 13 B, 13 C, 14 B and 14 C allow show modules that may be stackable or are adapted to be stackable. These modules have indentations shown in the top right and top left of each module that are adapted to receive the legs of a corresponding module. This allows the modules to be stacked upon one another. Modules, thus, have a lateral friction element that prevents the modules from moving.
In certain embodiments, stackable systems may also involve a top level not have a floor (floorless) and the bottom level not have a ceiling (ceilingless), creating a height volume area of twice the size of a module. Certain embodiments also are directed to mixed systems with a mixture of double-stack and single-stack systems. Such systems have a mixture of volume heights, as modules of smaller and greater sizes may be used in such systems.
FIGS. 23-28 show examples of stackable modules. FIG. 23 shows a type of stackable module that may be used is a multilayer or stacked system. Module 2300 is shown as being made of two modules, a lower module and an upper module. The lower module has four legs 2320 , 2325 , 2330 and 2335 . The four legs 2320 , 2325 , 2330 and 2335 support the upper module. Each of the four legs 2320 , 2325 , 2330 and 2335 has a bottom edge. The upper module also has four legs 2320 A, 2325 A, 2330 A, and 2335 A. Each of the four legs 2320 A, 2325 , 2330 A and 2335 A has a bottom edge. The four legs 2320 A, 2325 A, 2330 A and 2335 A support a horizontal deck 2310 A. Legs 2320 and 2325 are connected together by a beam 2340 . Window 2345 is shown above beam 2340 . Legs 2320 and 2335 are connected via beam 2360 with window 2365 shown above beam 2360 .
Channel 2355 is shown between leg 2330 and 2335 ; channel 2345 A is shown between leg 2320 A and 2325 A; channel 2375 A is shown between leg 2325 A and 2330 A; channel 2355 A is shown between let 2330 A and 2335 A; and channel 2365 A is shown between leg 2320 A and 2335 A. The lower module has opening 2310 in its ceiling instead of having a horizontal deck.
FIG. 24 shows a type of stackable module that may be used is a multilayer or stacked system. Module 2400 is shown as being made of two modules, a lower module and an upper module. The lower module has four legs 2420 , 2425 , 2430 and 2345 . The four legs 2420 , 2425 , 2430 and 2435 support the upper module. Each of the four legs 2420 , 2425 , 2430 and 2435 has a bottom edge. The upper module also has four legs 2420 A, 2425 A, 2430 A, and 2435 A. Each of the four legs 2420 A, 2425 , 2430 A and 2435 A has a bottom edge. The four legs 2420 A, 2425 A, 2430 A and 2435 A support a horizontal deck 2410 A.
Legs 2420 and 2435 are connected together by a beam 2460 . Window 2465 is shown above beam 2460 . Legs 2420 A and 2435 A are connected via beam 2460 A with window 2465 A shown above beam 2460 A. Legs 2425 and 2430 are connected together via beam 2470 . Window 2475 is shown above beam 2470 . Legs 2425 A and 2430 A are connected together via beam 2470 A. Window 2475 A is shown above beam 2470 A. Channel 2455 is shown between leg 2430 and 2435 ; channel 2455 A is shown between leg 2430 A and 2435 A; channel 2445 is shown between leg 2420 and 2425 ; and channel 2445 A is shown between leg 2320 A and 2325 A. The lower module has opening 2410 in its ceiling instead of having a horizontal deck.
FIG. 25 shows a type of stackable module that may be used is a multilayer or stacked system. Module 2500 is shown as being made of two modules, a lower module and an upper module. The lower module has four legs 2520 , 2525 , 2530 and 2545 . The four legs 2520 , 2525 , 2530 and 2535 support the upper module. Each of the four legs 2520 , 2525 , 2530 and 2535 has a bottom edge. The upper module also has four legs 2520 A, 2525 A, 2530 A, and 2535 A. Each of the four legs 2520 A, 2525 , 2530 A and 2535 A has a bottom edge. The four legs 2520 A, 2525 A, 2530 A and 2535 A support a horizontal deck 2510 A.
Legs 2520 and 2535 are connected together by a beam 2560 . Window 2565 is shown above beam 2560 . Legs 2520 A and 2535 A are connected via beam 2560 A with window 2565 A shown above beam 2560 A. Legs 2525 and 2530 are connected together via wall 2570 . Legs 2525 A and 2530 A are connected together via wall 2570 A. Perforations 2580 are shown in wall 2570 and wall 2570 A. Channel 2555 is shown between leg 2530 and 2455 ; channel 2555 A is shown between leg 2530 A and 2535 A; channel 2545 is shown between leg 2520 and 2525 ; and channel 2545 A is shown between leg 2520 A and 2525 A. The lower module has opening 2510 in its ceiling instead of having a horizontal deck.
FIG. 26 shows a type of stackable module that may be used is a multilayer or stacked system. Module 2600 is shown as being made of two modules, a lower module and an upper module. The lower module has four legs 2620 , 2625 , 2630 and 2645 . The four legs 2620 , 2625 , 2630 and 2635 support the upper module. Each of the four legs 2620 , 2625 , 2630 and 2635 has a bottom edge. The upper module also has four legs 2620 A, 2625 A, 2630 A, and 2635 A. Each of the four legs 2620 A, 2625 , 2630 A and 2635 A has a bottom edge. The four legs 2620 A, 2625 A, 2630 A and 2635 A support a horizontal deck 2610 A.
Legs 2620 and 2635 are connected together by a beam 2660 . Window 2665 is shown above beam 2660 . Legs 2620 A and 2635 A are connected together by a beam 2660 A. Window 2665 A is shown above beam 2660 A. Legs 2625 and 2630 are connected together via wall 2670 . Legs 2625 A and 2630 A are connected together via wall 2670 A. Legs 2630 and 2635 are connected together via wall 2650 . Legs 2630 A and 2635 A are connected together via wall 2650 A. Perforations 2680 are shown in wall 2670 , wall 2670 A, wall 2650 and wall 2650 A. Channel 2645 is shown between leg 2620 and 2625 ; and channel 2645 A is shown between leg 2620 A and 2625 A. The lower module has opening 2610 in its ceiling instead of having a horizontal deck.
FIG. 27 shows a type of stackable module that may be used is a multilayer or stacked system. Module 2700 is shown as being made of two modules, a lower module and an upper module. The lower module has four legs 2720 , 2725 , 2730 and 2745 . The four legs 2720 , 2725 , 2730 and 2735 support the upper module. Each of the four legs 2720 , 2725 , 2730 and 2735 has a bottom edge. The upper module also has four legs 2720 A, 2725 A, 2730 A, and 2735 A. Each of the four legs 2720 A, 2725 , 2730 A and 2735 A has a bottom edge. The four legs 2720 A, 2725 A, 2730 A and 2735 A support a horizontal deck 2710 A.
Legs 2720 and 2735 are connected together by a beam 2760 . Window 2765 is shown above beam 2760 . Legs 2720 A and 2735 A are connected together by a beam 2760 A. Window 2765 A is shown above beam 2760 A. Legs 2725 and 2730 are connected together via wall 2770 . Legs 2725 A and 2730 A are connected together via wall 2770 A. Legs 2730 and 2735 are connected together via wall 2750 . Legs 2730 A and 2735 A are connected together via wall 2750 A. Perforations 2780 are shown in wall 2770 , wall 2770 A, wall 2750 and wall 2750 A. Wall 2750 A also has opening 2718 and output pipe 2715 A. Channel 2745 is shown between leg 2720 and 2725 ; and channel 2745 A is shown between leg 2720 A and 2625 A. The lower module has floor 2710 A.
FIG. 28 shows a type of stackable module that may be used is a multilayer or stacked system. Module 2800 is shown as being made of two modules, a lower module and an upper module. The lower module has four legs 2820 , 2825 , 2830 and 2845 . The four legs 2820 , 2825 , 2830 and 2835 support the upper module. Each of the four legs 2820 , 2825 , 2830 and 2835 has a bottom edge. The upper module also has four legs 2820 A, 2825 A, 2830 A, and 2835 A. Each of the four legs 2820 A, 2825 , 2830 A and 2835 A has a bottom edge. The four legs 2820 A, 2825 A, 2830 A and 2835 A support a horizontal deck 2810 A.
Legs 2820 and 2835 are connected together by a beam 2860 . Window 2865 is shown above beam 2860 . Legs 2820 A and 2835 A are connected together by a beam 2860 A. Window 2865 A is shown above beam 2860 A. Legs 2825 and 2830 are connected together via wall 2870 . Legs 2825 A and 2830 A are connected together via wall 2870 A. Legs 2820 and 2825 are connected together via wall 2640 . Legs 2820 A and 2825 A are connected together via wall 2840 A. Perforations 2680 are shown in wall 2870 , wall 2870 A, wall 2840 and wall 2840 A. Channel 2855 is shown between leg 2830 and 2835 ; and channel 2855 A is shown between leg 2830 A and 2835 A. The lower module has opening 2810 in its ceiling instead of having a horizontal deck. Wall 2840 A has an opening 2890 A.
Dimensions of the modules shown in FIGS. 23-28 may be shown has having 12 inch beams (12 inches being the beam height); however, beams with other heights may be used, such as having beams that have a height of greater than 12 inches. The modules shown in FIGS. 23-28 are typically are approximately 8 feet wide and 8 feet deep and have a lower module height of 3 feet 8 inches and an upper modules height of 4 feet 8 inches when employing 12 inch beams. However, the modules shown in these figures can have a greater and smaller size. The modules can range in height, so as to allow a man to enter the module to service it.
Furthermore, modules typically have the ability to support 10,000 to 14,000 pounds of weight. However, modules may support additional weight based on materials used, such as having a steel frame internal to the concrete outer shell. Modules may be made of other materials known in the art, and may be made of materials that are more expensive and have greater load bearing capabilities, if desired.
Embodiments of the present invention have various advantages for the environment and have additional “green advantages” that have a positive impact on the environment. Notably, the present invention has a smaller environmental footprint, has more optimal use of area via geometry, and has less stone hauling and less material use than existing systems.
Embodiments of the present invention may do multiple processes, such as treatment, in a single module, and use less material and impact less surface area than existing systems. Embodiments of the present invention have stackability of the modules and/or may be a multilayered system, which reduces the environmental footprint of the systems.
Embodiments of the present invention have flow control to reduce erosion in receiving water, have water quality control treatment processes, have water reuse processing and storage, and also have irrigation runoff usage. Embodiments of the present invention have wastewater secondary grey water systems for use for irrigation, have non-sanitary water use and savings, treatment and storage.
Embodiments of the present invention may have water reuse for fire protection, temperature control of warmed parking lot runoff, wastewater detention relieving undersized public utilities loading, combine sewer storage and treatment, and surge flow protection. Embodiments of the present invention have ground water recharge, and may be used in conjunction with bio retention systems.
Embodiments of the present invention may support elements of green designs by virtue of the application. The material on construction is green by being a natural product. Embodiments of the present invention support fuel and energy reduction by a multi-use concept. Embodiments of the present invention support water reuse for secondary functions and water flow control to reduce the environmental impacts for receiving water, such as counterbalancing increased flows due to increase in hard surfaces.
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation and that various changes and modifications in form and details may be made thereto, and the scope of the appended claims should be construed as broadly as the prior art will permit.
The description of the invention is merely exemplary in nature, and thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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Modular storage and controlled outflow systems for controlling a flow of water and methods of assembly of modular storage and controlled outflow systems having indirect flow of water through the system. Modular systems for controlling a flow of water having beams extending across the modules to direct the flow of water in an indirect manner or a serpentine or semi-serpentine manner. Modular storage and controlled outflow systems for treatment and filtration of water.
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FIELD OF THE INVENTION
[0001] This invention relates to a device for filtering contaminants, such as particulates and vapor phase contaminants, from a confined environment such as electronic or optical devices susceptible to contamination (e.g. computer disk drives).
BACKGROUND OF THE INVENTION
[0002] Many enclosures that contain sensitive instrumentation must maintain very clean environments in order for the equipment to operate properly. Examples include enclosures with sensitive optical surfaces or electronic connections that are sensitive to particles and gaseous contaminants which can interfere with mechanical, optical, or electrical operation. Other examples include data recording devices such as computer hard disk drives that are sensitive to particles, organic vapors, and corrosive vapors. Still others include enclosures for processing, transporting or storing thin films and semiconductor wafers. Also included are electronic control boxes such as those used in automobiles and industrial applications that can be sensitive to particles, moisture buildup, and corrosion as well as contamination from fluids and vapors. Contamination in such enclosures originates from both inside and outside the enclosures. For example, in computer hard drives, damage may result from external contaminates as well as from particles and outgassing generated from internal sources. The terms “hard drives” or “hard disk drives” or “disk drives” or “drives” will be used herein for convenience and are understood to include any of the enclosures mentioned above.
[0003] One serious contamination-related failure mechanism in computer disk drives is static friction or “stiction”. Stiction results from the increased adhesion of a drive head to a disk while the disk is stationary plus increased viscous drag parallel to the head-disk interface. Contaminants on the disk change the surface energy and the adhesive forces between the head and disk; this also causes stiction. Vapors that condense in the gap between the head and disk can cause stiction. High-density disks are more sensitive to contamination-caused stiction because they are smoother and only thin layers of lubricants are present. Further exacerbating these effects are the newer lower energy, lower torque motors being used in smaller disk drives for portable computers and consumer applications.
[0004] Another serious contamination-related failure mechanism in computer disk drives is head crashes. Head crashes can occur when particles get into the head disk interface. High density drives may have less than 30 nanometer flying heights or spacing between the head and disk during operation and typically have disks rotating 7200 revolutions per minute or greater. Even submicron-sized particles can be a problem, causing the head to crash into the particle or the disk after flying over a particle, bringing the drive to an abrupt failure mode. Particles can also adversely affect data integrity and mechanical reliability of a drive, sometimes referred to as thermal asperity.
[0005] Internal particulate filters, or recirculation filters, are well known. These filters are typically pieces of filter media, such as expanded PTFE membrane laminated to backing material such as a polyester nonwoven, or “pillow-shaped” filters containing electret (i.e., electrostatic) filter media. They may be pressure fit into slots or “C” channels and placed in the active air stream such as near the rotating disks in a computer hard disk drive or in front of a fan in electronic control cabinets, etc. Alternatively, the recirculation filter media can be framed in a plastic frame. In very small drives, these small standup recirculation filters are so very small and the air being circulated by the very small disks is so low, that the filter effectiveness of these filters is minimal at best.
[0006] Internal adsorbent filters are also well known. A sorbent filter may be constructed of powdered, granular or beaded sorbent or sorbent mixture encapsulated in an outer expanded PTFE tube. Such a filter is manufactured by W. L. Gore & Associates, Inc., Elkton, Md., and is commercially available under the trademark GORE-SORBER® module. A second well known internal adsorbent assembly incorporates a layer of adsorbent, such as activated carbon/PTFE composite, between an encapsulating filter layer and layer of pressure sensitive adhesive that helps encapsulate the adsorbent as well as provides a means of mounting the adsorbent assembly on an interior wall in the enclosure.
[0007] A third internal adsorbent assembly incorporates a layer of adsorbent such as activated carbon/PTFE composite between two layers of filter media or is alternately wrapped in a layer of filter media and can be installed between slots or “C” channels much the way a recirculation filter is installed. These filters have minimal airflow through the filter.
[0008] All of these internal adsorbent filters adsorb vapor phase contaminants well, but they do not filter particulates very well. They can collect particles by some impaction of particles onto the filter (i.e., by having the larger particles impacting or colliding with the adsorbent filter as particle-laden air speeds around the filters) or by diffusion of particles onto the filter. However, they do not perform nearly as well as standard recirculation filters that work by a combination of sieving (mechanically capturing particles too large to pass through the pore structure of the filter), impaction (capturing particle too large to follow the bending air streams around filters or the fibers of the filter), interception (capturing particles that tend to follow the air streams, but are large enough to still intercept a filter fiber or in other words those particles with a diameter equal to or less than the distance between the fiber and the air stream line), and diffusion (capturing smaller particles buffeted about by air molecules in a random pattern and coming into contact with a filter fiber to become collected).
[0009] A multifunction filter providing a breather filter and a recirculation filter with optional; adsorbents can solve many of the problems associated with the previous filters. A multifunction filter is described in U.S. Pat. No 6,395,073 to Dauber. This is an adequate solution when the space can be found for placing such a combination filter.
[0010] Disk or shroud Filters are also known. Such filters are placed under the disk, or in close proximity to its perimeter. Because typically carpet and shroud filters use fibrous media. It is difficult to position this fibrous media very near the computer disk, because the fibers can extend from the filter and contact the computer disk. This may cause more particles to be generated and deposited onto the hard disk, which can lead to a catastrophic failure of the hard drive.
[0011] However, the limited space in smaller drives often necessitates that these filters be placed either directly over or under the disks. Moreover, particularly in smaller drives where the disks are very close to the top cover and base plate, these filters can perform better in these locations than in standard upright locations traditionally used in larger drives. In multifunction filters installed within small drives, or within any drive where the clearance between the filter and the drive components is small, fibers protruding from the filter present problems. The clearance between a hard disk and the filter may be less than 0.5 mm and a filter must fit within this thickness as well as leave clearance for the disks to spin without possible contact with the filter.
[0012] What is needed is a recirculation filter material with low fiber height to permit the material to be used as a carpet or shroud filter.
[0013] Accordingly, the present invention provides a reduced fiber carpet/shroud filter material that can filter the air of particles to prevent fibers from contacting and interfering with any moving parts within the enclosure. The invention also provides a carpet or shroud filter with reduced fiber height.
[0014] The invention may optionally include adsorbents to filter gaseous contaminants from the enclosure.
SUMMARY
[0015] In one aspect, the invention is a laminated recirculation filter for mounting on an impermeable surface within a disc drive, the laminated recirculation filter comprising an adhesive layer; a filter layer having a first surface adjacent to the adhesive layer and a second surface opposite the first surface, the filter layer comprising a plurality of fibers; and a membrane layer having a first surface laminated to the second surface of the filter layer and a second surface opposite the first surface, wherein the fibers project from the second surface of the membrane layer for an orthogonal distance of less than 0.005 inches.
[0016] In another aspect, the invention is laminated recirculation filter for mounting on an impermeable surface within a disc drive, the laminated recirculation filter comprising an adhesive layer; a filter layer having a first surface adjacent to the adhesive layer and a second surface opposite the first surface, the filter layer comprising a plurality of fibers; and a membrane layer having a first surface laminated to the second surface of the filter layer and a second surface opposite the first surface, wherein less than less than 2 fibers per mm 2 project for an orthogonal distance of more than 0.010 inches above the second surface of the membrane layer.
[0017] In still another aspect, the invention provides an electret recirculation filter for mounting on an impermeable surface within a disc drive, the electret recirculation filter comprising an adhesive layer; and a electret filter layer having a first surface adjacent to the adhesive layer and a second surface opposite the first surface, the electret filter layer comprising a plurality of fibers; wherein the fibers project from the second surface of said electret layer for an orthogonal distance of less than 0.010 inches.
[0018] In yet another aspect, the invention includes an electret recirculation filter for mounting on an impermeable surface within a disc drive, the electret recirculation filter comprising an adhesive layer; and an electret filter layer having a first surface adjacent to the adhesive layer and a second surface opposite the first surface, the electret filter layer comprising a plurality of fibers and being less than about 0.005 inches thick; wherein less than less than 2 fibers per mm 2 project for an orthogonal distance of more than 0.005 inches above the second surface of the electret filter layer.
[0019] In a still further aspect, the invention includes a laminated recirculation filter for mounting on an impermeable surface within a disc drive, the laminated recirculation filter comprising an adhesive layer; a polyester nonwoven filter layer having a first surface adjacent to the adhesive layer and a second surface opposite the first surface, the polyester nonwoven filter layer comprising a plurality of fibers and being less than about 0.005 inches thick; and a membrane layer comprising an ePTFE membrane, the membrane layer having a first surface laminated to the second surface of the polyester nonwoven filter layer and a second surface opposite the first surface, the membrane layer having a thickness of less than about 0.001 inches, wherein the fibers project from the second surface of the membrane layer for an orthogonal distance of less than 0.010 inches.
[0020] In a still further aspect, the invention provides a laminated recirculation filter for mounting on an impermeable surface within a disc drive, the laminated recirculation filter comprising an adhesive layer; a polyester nonwoven filter layer having a first surface adjacent to the adhesive layer and a second surface opposite the first surface, the polyester nonwoven filter layer comprising a plurality of fibers and being less than about 0.005 inches thick; and a membrane layer comprising an ePTFE membrane, said membrane layer having a first surface laminated to the second surface of the nonwoven filter layer and a second surface opposite the first surface, the membrane layer having a thickness of less than about 0.001 inches, wherein less than less than 2 fibers per mm 2 project for an orthogonal distance of more than 0.005 inches above the second surface of the membrane layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The operation of the present invention should become apparent from the written description when considered in conjunction with the following drawings, in which:
[0022] FIGS. 1A and 1B are a top and side view respectively of an embodiment of the filter unit of the present invention with a reduced fiber filter material and adhesive for mounting within an enclosure;
[0023] FIG. 2 is a side view of another embodiment of the filter unit of the present invention with a laminated reduced fiber filter comprising a membrane, filter layer and adhesive layer for mounting within an enclosure;
[0024] FIG. 3 is a top view of an embodiment of the filter unit of the present invention applied onto an enclosure surface such as the underside of a lid to a computer hard disk drive;
[0025] FIG. 4 is a side view of an embodiment of the filter unit of the present invention installed within the top cover of a computer hard disk drive;
[0026] FIG. 5 is a side view of another embodiment of the filter unit of the present invention with an adsorbent layer between an adhesive layer and a filter layer;
[0027] FIG. 6 is a side view of another embodiment of the filter unit of the present invention with an adsorbent layer, and an additional layer with an aperture therein;
[0028] FIG. 7 is a top view of another embodiment of the filter unit of the present invention as it would be applied as a shroud filter to a side wall of a hard disk drive;
[0029] FIG. 8 is a top view of another embodiment of the filter media of the filter unit of the present invention where the filter media has been bonded at various points (often referred to as point bonded) to control extruding fibers;
[0030] FIGS. 9A and 9B are side illustrative views of a fibrous filter media before and after calendaring respectively, showing a reduction of fibers protruding from the filter material after calendering;
[0031] FIGS. 10A and 10B are side illustrative views of a fibrous filter media before and after burnishing respectively, showing how the lengths of protruding fibers have been reduced by melting them back to the base filter media;
[0032] FIG. 11 shows a photomicrograph of the surface of an electret media. The marker is 0.0130 inches showing that fibers extend can normally extend beyond the surface of the filter material by 0.05 inches or more.
[0033] FIG. 12 shows a photomicrograph of the surface of the inventive reduced fiber filter media.
[0034] FIG. 13 shows a photomicrograph of the surface of a reduced fiber filter laminate in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The present invention provides an improved filter media for a disk drive and an improved filter comprising the inventive media. The filter may be used as a shroud or carpet type particle and optionally a particle and vapor filter for filtering internal particles and vapors within a computer hard disk drive. The invention reduces fiber height to prevent fibers from touching moving surfaces such as computer hard disks or heads and prevents such fibers from interfering with the operation of the device into which the filter is installed.
[0036] In the latter aspect, the filter includes fibrous filter material, but the filter is constructed such that very few fibers project from the surface of the filter. This allows the filter to have a sufficiently low profile that it can be mounted in small spaces within a disk drive, such as a carpet filter, located beneath the disk, or upon a shroud filter located on a shroud in close proximity to the disk perimeter. This low fiber profile can be accomplished a number of ways: By calendaring the filter media with heat and pressure, fibers are secured within the filter and prevented from extending from the filter surface. Alternatively, by burnishing or treating with a flame or heat process, any extended fibers are melted. In yet another technique, the filter material is treated with adhesives or bonding material and then compressed to bind the fibers within the body of the filter. For instance, this could be accomplished by applying a liquid adhesive before pressing the fibers into the body of the filter.
[0037] The reduced fiber filter media may comprise a calendared electrostatic triboelectret material. Useful electrostatic triboelectret materials are available from W. L. Gore and Associates, Inc. under the trademark GORE-TRET® recirculation filters. This media is very efficient (e.g., in excess of 90% @0.3 micron) and also very permeable (e.g., less than 1 mm H 2 O at 10.5 fpm or 3.2 m/min). While this media loses its electrostatic charge while being washed with deionized water, it immediately regains its efficiency upon drying due to the triboelectric effect of the mix of dissimilar fibers.
[0038] Although this media has many fibrous projections, the inventors have discovered that by calendaring, the electret the fibers can be compressed and bound within the filter media. Surprisingly, calendaring the electret media does not cause significant loss of filter performance. A calendered electret would not be expected to perform as well as a uncalendared material filter because calendaring of the material would be expected to increase the pressure drop through the media, causing more air to bypass the filter and remain unfiltered reducing filtration performance. Moreover, because electrostatic media works by an electric field within the media, or essentially by bending the trajectory of a particle to an oppositely charged fiber, by making the media significantly thinner one would reduce the expected dwell time within the media which would presumably lower the material's collection efficiency.
[0039] The electret can be calendared to a desired thickness and fiber height by varying the temperature, pressure and process time of the calendering process. Calendering is a process where heat and pressure are applied to the fibrous material to compress and either heat set the material to reduce thickness or soften or melt a low melt fiber component upon cooling, that component stiffens or solidifies which holds the entire fibrous media at the reduced thickness. Too much heat and pressure will cause the material to lose the fibrous characteristic of the media or to melt the media entirely back to a plastic state. In some cases, excessive calendaring may solidify the fibers to form a plastic sheet. Enough heat and pressure is applied to get to a steady state material of the desired thickness and fiber containment. Too little heat may provide inefficient inter-fiber binding to reduce fiber projection height. In application, the filter may be exposed to higher temperature. This may permit the calendared material to return to its pre-calendared dimensions. The desired heat, pressure and processing time will be material and construction dependent, but is readily determined for any given fibrous filter material.
[0040] Although triboelectret materials are preferred, other calendared filter materials can also be used for the improved reduced fiber filtration layer. Such materials could include alternative electret or triboelectret materials that yield high efficiencies and low resistances to airflow. They could also be other non-woven or spun bond materials, filter papers, filter media, filter membranes such as polypropylene membranes or cast polymeric membranes, or some combination of filter materials.
[0041] Other processes can also be employed to reduce fiber height. For instance, the electret non-woven media can be burnished or treated with a flame or other heat source that melts protruding fibers back onto the main fiber web. These processes will add enough heat to the protruding fibers to melt them back towards the main web without adding too much heat to melt the entire fibrous material or web. Again temperature and processing time, or the amount of time the heat is applied, will be dependent upon the material composition of the fibers you are melting, but the projecting fibers must reach the melt temperature for the polymer the fiber is composed of. In an alternative technique for reducing fiber height, additives such as adhesives are added to the filter material and run through rollers to compress the material and cured to hold fibers onto the main web. Adhesives that could be used would include thermoset or thermoplastic materials with lower melt temperatures than the fibers of the filter media and then be heat processed to set the thickness and fiber retention. Other adhesives such as liquid adhesives or multipart adhesives could be added to the filter material before or while being compressed and cured as in curing with air, ultraviolet light or other means.
[0042] Turning now to the figures, FIGS. 1A and 1B show a top and side view respectively of a first embodiment of the reduced fiber filter 10 of the present invention. FIG. 1B shows a reduced fiber filter media 11 on an adhesive layer 12 for easy mounting onto an enclosure surface. Preferably filter media 11 is a calendared electret media.
[0043] FIG. 2 shows a side view of another embodiment of the laminated reduced fiber filter of the present invention. FIG. 2 shows a membrane 60 laminated to an electret filter layer 61 , which is disposed upon adhesive layer 12 .
[0044] FIG. 3 shows a top view of an embodiment of the improved reduced fiber filter 10 of the present invention as it would be applied to a surface 13 of an enclosure. For example, it is shown as it would be installed as a disk filter 10 to the underside of a cover 13 of a computer hard disk drive.
[0045] FIG. 4 shows a side view of an embodiment of a reduced fiber filter 10 of the present invention as it would be installed as a disk filter on the top cover 19 of a computer hard disk drive 14 with spinning recording media 15 .
[0046] FIG. 5 shows a side view of another embodiment of the improved reduced fiber filter of the present invention. In this aspect, a reduced fiber filter layer 11 is placed over an adsorbent layer 20 and both are held in place and together with adhesive layer 12 .
[0047] FIG. 6 is a side view of another embodiment of the reduced fiber filter 10 of the present invention with an adsorbent layer 21 , filter layer 11 , and an additional layer with an aperture therein 12 a that can be an adhesive and that along with adhesive layer 12 hold the filter together and in place and presents a flat top surface that can be important to reduce any potential turbulence that might be caused by the filter when in place in the Disk Drive;
[0048] FIG. 7 shows a top view of an embodiment of the improved reduced fiber filter 10 of the present invention as it would be applied to a surface 18 of an enclosure. In the Figure, it is shown as it would be installed as a shroud filter 10 to a side wall 18 of a computer hard disk drive 14 with spinning recording media 15 , recording head 16 , and armature 17 . In a preferred embodiment, shroud filter 10 would include a pressure sensitive adhesive for easy mounting.
[0049] FIG. 8 shows another embodiment of a filter media with reduced fiber height. In this embodiment, fiber height is reduced by a pattern of point bonding. The figure shows a top view showing a pattern of bonding sites ( 50 ) that can be applied to a electret or other fibrous filter material to tie down fibers and try to limit extended fibers. The spacing of bonds is dependent upon a number of factors such as fiber diameter, fiber length, fiber material and the desired fiber tie-down or reduction or protruding fibers desired. Fiber spacing will also impact filter thickness.
[0050] FIGS. 9A and 9B illustrate an electret before and after calendering of a filter material. In FIG. 9A , before calendering, there can be some fibers that have ends 54 pointing out of the surface of the filter 52 as well as fibers 53 that are attached to the surface at each end, but lift in the middle or bow out away from the surface of the filter. After calendaring, as shown in FIG. 9B , the fibers are compressed and bonded or further mechanically intertwined such that they no longer protrude from the surface of the filter.
[0051] Similarly, FIG. 11 shows a photomicrograph of a standard electret filter material. The photomicrograph includes a reference marker which is 0.013 inches. It can be seen that there are many fibers that extend 0.05 inches or more from the surface of the filter. In contrast, FIG. 12 shows a photomicrograph after the electret has been calendered (like Example 3 of the present invention) and it can be clearly seen that no more than two fiber in the field of view of 3.5 mm come close to extending 0.005 inches from the surface of the filter.
[0052] Burnishing may also be used to construct the reduced fiber filter material. FIG. 10A and 10B show an illustrated before and after burnishing respectively of a filter. In FIG. 10A prior to burnishing fibers 56 and 57 can extend far from the filter surface 55 . After burnishing, fibers 56 are melted is back to the filter surface for containment. There may be some end fibers 57 that still project from the ends, but typically such fibers cut off during the manufacturing and die cutting of finished filters.
[0053] FIG. 13 shows a photomicrograph of the surface of another embodiment showing no measurable fibers extending from or through the membrane. In this embodiment another layer (a layer of CONWED polypropylene plastic scrim) was added as an aid for lamination of the membrane to the electret filter. Here the membrane can be seen following the form of the CONWED plastic used in the construction of the filter sample, but no fibers are visible.
[0054] Filter material may be either single layer filter or multiple layer filter layered or laminated together. Multiple filter layers may contain membrane layers as they may be preferred for fiber containment and thickness control while adding filtration benefits. Single filter layers would have improved fiber containment via calendaring or other processes to reduce fiber protrusion.
[0055] The inventive filters may include a support layer. A preferred support layer or laminate filter layer is a Reemay 2014 polyester nonwoven, 1.0 oz/yd2 available from Reemay, Inc., Old Hickory, Tenn. If a reduced thickness is required, a lighter weight version could be used, or a calendaring of the material can affected either prior to or during any lamination step. Another preferred support layer is a layer of an electrostatic triboelectret material available in finished filter form from W. L. Gore and Associates, Inc. under the trademark GORE-TRET® recirculation filters. Other filter materials can also be used as support layers. They could be alternative electret or other triboelectret materials that yield high efficiencies and low resistances to airflow. They could also be other filter papers or a combination of such filter materials.
[0056] An adsorbent layer or layers may be added to any of the embodiments described above, to make a combination filter effective for both particle and vapor filtration. The adsorbent can be treated for the adsorption of specific gaseous species such as acid gasses.
[0057] The adsorbent may comprise one or more layers of 100% adsorbent materials, such as granular activated carbon, or may be a filled product matrix such as a scaffold of porous polymeric material compounded with adsorbents that fill some of the void spaces. Other possibilities include adsorbent impregnated nonwovens or beads on a scrim where the non-woven or scrim may be cellulose or polymeric and may include latex or other binders. Still other possibilities include porous castings or tablets of adsorbents and fillers that are polymeric or ceramic. The adsorbent can also be a mixture of different types of adsorbents.
[0058] Examples of adsorbent materials that may be contained within the adsorbent layer include: physisorbers (e.g. silica gel, activated carbon, activated alumina, molecular sieves, adsorbent polymers, etc.); chemisorbers (e.g. potassium permanganate, potassium carbonate, potassium iodide, calcium carbonate, calcium sulfate, sodium carbonate, sodium hydroxide, calcium hydroxide, powdered metals or other reactants for scavenging gas phase contaminants); as well as mixtures of these materials. For some applications, it may be desirable to employ multiple layers of adsorbent materials, with each layer containing different adsorbents to selectively remove different contaminants as they pass through the filter.
[0059] A preferred embodiment of the adsorbent layer utilizes an sorbent filled PTFE sheet wherein the sorbent particles are entrapped within the reticular PTFE structure as taught by U.S. Pat. No. 4,985,296 issued to Mortimer, Jr. and specifically incorporated herein by reference. Ideally, particles are packed in a multi-modal (e.g. bi-modal or tri-modal) manner with particles of different sizes interspersed around one another to fill as much of the available void space between particles as is possible, so as to maximize the amount of active material contained in the core. This technique also allows a number of sorbents to be filled into a single layer. The core can then be expanded to allow some airflow or needled to allow more airflow. Expanding the core reduces loading density but offers a more uniform sorbent barrier. Other processing, such as needling or the like, may be desirable to obtain the desired adsorbent and airflow performance. Additionally, ridges or any airflow aiding patterns may be pressed or formed in the adsorbent layer to assist in conditioning or reduction of turbulence of the airflow within the hard disk drive.
[0060] The PTFE/adsorbent composite can easily be made in thicknesses from less than 0.001″ to 0.400″ and greater allowing a great deal of flexibility in finished filter thickness and adsorbent loading. Additionally, sorbent densities approximating 80-95% of full density are possible with multi-model packing and physical compression, so that maximum adsorbent material can be packed per unit volume. The use of PTFE as the binding element also does not block the adsorbent pores as do binders such as acrylics, melted plastic resins, etc.
[0061] Additional layers may be added for dimensional stability or added fiber containment. Those can be nonwovens similar to the Reemay 2104 previously described, or they may be any other materials of convenience.
[0062] Adhesive layers can be used for convenience in the construction of the filters. The adhesive must have a sufficient peel strength to withstand application use and meet any use specifications that may exist such as high temperature, solvent resistance, regulatory approval, repositionable, or low outgassing specifications. A typical low outgassing specification is to pass ASTM E-595-84 specification of less than 1% total mass loss and 0.1% collected volatile condensable material.
[0063] A preferred adhesive is a double sided adhesive comprising of a layer of 0.001″ (0.0025 cm) thick permanent acrylic pressure sensitive adhesive applied to both sides of a polymeric film carrier layer. Thicker adhesives may also be used and may be preferred to attach filters onto hard to adhere materials such as a rough enclosure surface.
[0064] The polymeric film may be, for example, a polyethylene, polypropylene, polyester, polycarbonate, polyurethane or polyvinyl chloride film. Preferably, the film comprises a polyester film of from 0.0005″ thick to 0.005″ thick although thicker films could be used if desired. A preferred film is a MYLAR® film manufactured by E. I. Dupont Co.
[0065] An adhesive can be disposed on the polymer film by, for example, coating, painting, spraying, dipping, laminating, or otherwise applying the adhesive to the layer. In some embodiments, adhesive may be pre-applied on a commercially available film. In some cases the adhesive may be on a release layer. The release layer is removed prior to filter assembly or installation and an unsupported adhesive remains to be used in the filter construction. This can be especially useful when the filter needs to be very thin such as in new 1.0″ and 0.85″ drives that may only be up to 3 mm thick including the housing and the recording head and hard disk. A commercially available transfer adhesive is available from 3M, part 9457 and a commercially available double-sided adhesive is 3M 415 which both employ an A-40 acrylic adhesive all commercially available from Minnesota Mining Manufacturing, Inc. of Minneapolis, Minn.
[0066] A preferred membrane to use on a laminated construction of the present invention is a membrane layer of expanded PTFE membrane made as described in U.S. Pat. No. 4,902,423 to Bacino et al. This membrane has minimal resistance to airflow yet contains fibers well when laminated to a filter or support layer. Such membranes are available in finished form from W. L. Gore and Associates, Inc. in Elkton Md.
[0000] Measurement of Fiber Length From a Filter Surface
[0067] Protruding fibers from a filter surface can be seen with an optical microscope such as a Nikon SMZ-2T photo stereo microscope. Protruding fibers can be measured by comparing them to a scale placed in the same field of view. Photomicrographic and measurement systems can be added to the microscope such as a FX photomicrographic system and Video Image Marker Measurement Systems from Nikon Corporation to include length comparators or markers in photomicrographs for length measurement and comparisons.
[0000] Assembly of the Device into a Modified Drive:
[0068] Examples of the present invention were tested for particulate filtration performance using a commercially available 1.0 inch form factor 4 GB disk drive from Hitachi Corporation. Modification consisted of drilling two holes in the drive lid. One hole was used to allow the introduction of contaminants, and another to sample the internal drive atmosphere during the performance testing. Installed over each of the holes in the lid was a stainless steel fitting, the fittings were centered over each hole and attached and sealed using two-component epoxy. Tubing was used to connect the particle supply source to the drive inlet fitting and to connect the particle counter to the outlet fitting. The drive lid was cleaned using isopropanol and clean pressurized air to remove any oils and particles created during modification. Following modification of the drive, the filters were mounted onto the drive lid directly over the hard disk opposite to the side of the disk where the head reads and records data. A comparison was made with the existing stand up recirculation filter as supplied and received in the drive as purchased.
[0000] Disk Drive Recirculation Filter Test:
[0069] This test is designed to measure the effectiveness of a particle filter in reducing the particle concentration inside a disk drive from an initial state in which the drive has been charged with particles. It can be used for standard standup recirculation filters as well as shroud and disk type recirculation filters as described in this invention. The performance of the recirculation filter is quantified in terms of a cleanup time, which is defined as the time required to reduce the particle counts inside the drive to a fixed percentage of their initial value. A typical metric is the time it takes to clean up 90% of the particles in a drive and is referred to as a t 90 value. Lower t 90 values indicates faster clean up and improved filter performance.
[0070] To test the efficacy of the recirculation filter, the filter samples were tested in the modified disk drive. The existing breather hole in the drive was left uncovered in order to provide a means for venting any overpressure from the drive and to allow air to enter the drive during periods when the drive environment was being sampled without air being purposefully introduced into the drive. The lid was fastened securely to the baseplate. A tube supplying an aerosol of 0.1 μm particles was connected to the inlet port in the drive lid upstream of the filter based on the direction of disk rotation. The particles were 0.1 μm polystyrene latex spheres supplied by Duke Scientific Corporation and they were diluted in deionized water and atomized with an atomizer supplied by TSI Corporation in Minnesota USA. A second tube for sampling the internal atmosphere of the drive connected the laser particle counter (LPC) to the outlet port in the drive lid downstream of the filter. A Model HS-LAS laser aerosol spectrometer from Particle Measuring Systems Inc., in Colorado USA was used to count the particles. Sample flow rate out of the drive and through the counter was maintained by precision mass flow controllers at 0.10 cc/sec and sheath flow through the LPC was maintained at 15 cc/sec. Counts of 0.1 μm particles were obtained once per second by the LPC and stored on a computer disk drive for later analysis. The test was performed with the drive located in a laminar flow hood fitted with a HEPA filter in the air intake, in order to maintain a controlled test environment with an extremely low ambient particle concentration. Samples of a standard sized and construction recirculation filter were used from the drive as purchased. A control containing no recirculation filters was also run.
[0071] The recirculation filter test consisted of the following sequence: With the drive turned off and particle laden air passing through the drive, the counts of 0.1 μm particles were monitored until a steady state count was achieved, typically around 2000 counts per second. At that time the drive was turned on while sampling of the internal drive atmosphere continued. The concentration of 0.1 μm particles was again monitored to a steady state condition. The drop in concentration is due to the recirculation of air through the drive and the filter, impaction of the particles on drive surfaces and other particle collection means. Different filter constructions and locations will have different impacts on the steady state recorded when the drive is on and these differences can be analyzed to determine optimal filter constructions and locations.
[0072] Data obtained was the counts per second when the drive is turned off labeled as Ca and counts per second when the drive is turned on labeled Css. There will be a no filter Css as well as Css's for every filter tested. A t 90 is calculated by the following formula: t 90 =2.3 V/Q(1/R f −1) where t 90 is the calculated time to remove 90% of the particles in seconds, V is the open drive volume or drive air volume, Q is the particle flow rate into the drive (which in this case also equals the sampling rate of the particle counter as the sampling flow was used to pull the particle laden air from the drive to the LPC and from the particle laden source into the drive), and 1/R f =Ca/Css.
[0073] Three individual tests were performed in order to check reproducibility and eliminate error from noise in the background counts. The results from the three tests were averaged to obtain the average cleanup times for 0.1 μm particles. Further analysis can calculate a RCUR time by dividing the t 90 time of the filter by the t 90 time of the no filter run to get a number referred to as the RCUR number or Relative Clean-Up Ratio. The RCUR number is a better comparative number between different drives and different test setups because it references a filter performance to a no filter performance in a particular drive being tested.
[0074] A 1.0″ computer hard disk drive was modified as stated above for testing particle cleanup in a modified drive where inlet and outlet ports were mounted to the lid of the hard drive. The samples were tested in accordance to the procedures previously outlined. Each sample was tested in a different 1.0″ drive, but they were all from Hitachi Corporation in Japan. There is variability in the absolute times from drive to drive in these tests. Part of that variability may come from drive leakage as these drives are often not perfectly sealed and can become even less sealed after opening and closing them to insert filters and to locate the ports on the drive lid. But the Relative Clean-Up Ratio compares each filter as tested to a no filter test for that particular drive and test setup and as such removes much of the drive to drive variability.
[0075] Without intending to limit the scope of the present invention, the following examples illustrate how the present invention may be made and used.
EXAMPLE 1
[0076] Samples were constructed and the recirculation filter effectiveness of the improved reduced fiber recirculation filter was evaluated. The sample filter consisted of an PTFE membrane with a Frazier number of around 200F as manufactured by W. L Gore and Associates as described in U.S. Pat. No. 4,902,423, laminated to a calendared 2.0 oz/yd2 Reemay nonwoven polyester available from BBA Fiberweb Inc., in Old Hickory Tenn. to contain fibers. Total laminate thickness was about 0.015″.
[0077] The sample filter was then cut from this material in the shape of a semicircle to fit under the disk but around any motor mount interference. A 0.006″ double sided adhesive supplied by Adhesive's research in Glenn Rock Pa. was placed under the non-woven polyester layer to complete the filter assembly. A no filter test was run as a control. The filters were tested using the Disk Drive Recirculation Filter Test described above. The results are reported in Table 1.
TABLE 1 Absolute clean Relative up time Clean up T 90 [secs] Ratio, RCUR No filter Condition 11.7 Example 1 5.8 0.49
EXAMPLE 2
[0078] Samples were made up to test the recirculation filter efficacy of another improved reduced fiber recirculation filter. The exemplary inventive filter consisted of an ePTFE membrane with a Frazier number of around 200 F used in Example 1 laminated to a 70 gm/m2 electret filter material as supplied by W. L. Gore and Associates. The original thickness of the electret and membrane is about 0.052″+/−0.010″. The layers were laminated together utilizing a T-shirt press manufactured by Geo Knight and Company in Brockton Mass. Conditions used for this sample was healing the top platen to 340 F (171 C) and utilizing 90 PSI air pressure to the platen and holding the set for 30 seconds. The laminate was then further compressed by inverting the sample and reheating it with the same temp and pressure for seven seconds. Final laminate thickness was about 0.017″. A filter was then cut from this laminate again and attached to a disk drive utilizing a 0.006″ thick double sided acrylic pressure sensitive adhesive from Adhesive's Research. A no filter test was also run as a control and the standard stand-up filter as supplied in the drive was also tested. The results are reported in Table 2. Further examination of the surface of the sample is shown in FIG. 13 which can be compared to a standard electret filter from FIG. 11 .
TABLE 2 Absolute clean Relative up time Clean up t 90 [secs] Ratio, RCUR No filter Condition 25.4 Standard Recirculation 24.8 0.98 Filter Example 2 4.0 0.16
[0079] Another embodiment of reduced fiber recirculation filter was constructed and compared to the standard filter was the standard stand up filter for the drive as supplied and purchased. The exemplary inventive filter sample consisted of a layer of 30 gm/m2 electret purchased from Hollingsworth and Vose Company in East Walpole Mass. The electret had an original thickness of 0.032″+/−0.010″. The material was calendered using the same T-shirt press as used in Example 2 above but without membrane. The electret was placed between two high temperature nonstick sheets. The conditions used to calender the material, was 300 F (149 C) on the top platen, with 60 PSI air pressure supplied to the machine and held for 20 seconds. A final thickness of 0.0115″ was obtained. A filter was cut from the material again utilizing a 0.004″ thick double sided acrylic pressure sensitive adhesive from Adhesive's Research. A no filter test was run as a control. The standard stand-up filter as supplied in the drive was also tested. The results are reported in Table 3. Further examination of the surface of the filter is shown in FIG. 12 which can be compared to a standard electret filter in FIG. 11 .
TABLE 3 Absolute clean Relative up time Clean up t 90 [secs] Ratio, RCUR No filter Condition 42.9 Standard Recirc Filter 38.0 0.89 Example 2 12.8 0.30
[0080] While particular embodiments of the present invention have been illustrated and described herein, the present invention should not be limited to such illustrations and descriptions. It should be apparent that changes and modifications may be incorporated and embodied as part of the present invention within the scope of the following claims:
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The invention relates to a device for filtering contaminants, such as particulates and vapor phase contaminants, from a confined environment such as electronic or optical devices susceptible to contamination (e.g. computer disk drives) by providing an improved reduced fiber filter.
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BACKGROUND
An oil well typically goes through a “completion” process after it is drilled. Casing is installed in the well bore and cement is poured around the casing. This process stabilizes the well bore and keeps it from collapsing. Part of the completion process involves perforating the casing and cement so that fluids in the formations can flow through the cement and casing and be brought to the surface. The perforation process is often accomplished with shaped explosive charges. These perforation charges are often fired by applying electrical power to an initiator. Applying the power to the initiator in the downhole environment is a challenge.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a perforation system.
FIG. 2 illustrates a perforation apparatus.
FIG. 3 illustrates the perforation system after one of the perforation charges has been fired.
FIG. 4 is a block diagram of a perforation apparatus.
FIG. 5 is an exploded view of a pressure activated switch.
FIG. 6 is a perspective view of elements of a pressure activated switch.
FIG. 7 is a perspective view of a pressure activated switch.
FIG. 8 is a cross-sectional view of a pressure activated switch before it is actuated.
FIG. 9 is a cross-sectional view of a pressure activated switch after it is actuated.
FIGS. 10 , 11 , and 12 are schematics of a perforation apparatus.
FIG. 13 is a block diagram of an environment for a perforation system.
DETAILED DESCRIPTION
In one embodiment of a perforation system 100 at a drilling site, as depicted in FIG. 1 , a logging truck or skid 102 on the earth's surface 104 houses a shooting panel 106 and a winch 108 from which a cable 110 extends through a derrick 112 into a well bore 114 drilled into a hydrocarbon-producing formation 116 . In one embodiment, the derrick 112 is replaced by a truck with a crane (not shown). The well bore 114 is lined with casing 118 and cement 120 . The cable 110 suspends a perforation apparatus 122 within the well bore 114 .
In one embodiment shown in FIGS. 1 and 2 , the perforation apparatus 122 includes a cable head/rope socket 124 to which the cable 110 is coupled. In one embodiment, an apparatus to facilitate fishing the perforation apparatus (not shown) is included above the cable head/rope socket 124 . In one embodiment, the perforation apparatus 122 includes a casing collar locator (“CCL”) 126 , which facilitates the use of magnetic fields to locate the thicker metal in the casing collars (not shown). The information collected by the CCL can be used to locate the perforation apparatus 122 in the well bore 114 . A gamma-perforator (not shown), which includes a CCL, may be included as a depth correlation device in the perforation apparatus 122 .
In one embodiment, the perforation apparatus 122 includes an adapter (“ADR”) 128 that provides an electrical and control interface between the shooting panel 106 on the surface and the rest of the equipment in the perforation apparatus 122 .
In one embodiment, the perforation apparatus 122 includes a plurality of select fire subs (“SFS”) 130 , 132 , 134 , 135 and a plurality of perforation charge elements (or perforating gun or “PG”) 136 , 138 , 140 , and 142 . In one embodiment, the number of select fire subs is one less than the number of perforation charge elements.
The perforation charge elements 136 , 138 , 140 , and 142 are described in more detail in the discussion of FIG. 4 . It will be understood by persons of ordinary skill in the art that the number of select fire subs and perforation charge elements shown in FIGS. 1 and 2 is merely illustrative and is not a limitation. Any number of select fire subs and sets of perforation charge elements can be included in the perforation apparatus 122 .
In one embodiment, the perforation apparatus 122 includes a bull plug (“BP”) 144 that facilitates the downward motion of the perforation apparatus 122 in the well bore 114 and provides a pressure barrier for protection of internal components of the perforation apparatus 122 . In one embodiment, the perforation apparatus 122 includes magnetic decentralizers (not shown) that are magnetically drawn to the casing causing the perforation apparatus 122 to draw close to the casing as shown in FIG. 1 . In one embodiment, a setting tool (not shown) is included to deploy and set a bridge or frac plug in the borehole.
FIG. 3 shows the result of the explosion of the lowest perforation charge element. Passages 302 (only one is labeled) have been created from the formation 116 through the concrete 120 and the casing 118 . As a result, fluids can flow out of the formation 116 to the surface 104 . Further, stimulation fluids may be pumped out of the casing 118 and into the formation 116 to serve various purposes in producing fluids from the formation 116 .
One embodiment of a perforation charge element 136 , 138 , 140 , 142 , illustrated in FIG. 4 , includes 7 perforating charges (or “PC”) 402 , 404 , 406 , 408 , 410 , 412 , and 414 . It will be understood that by a person of ordinary skill in the art that each perforation charge element 136 , 138 , 140 , 142 can include any number of perforating charges.
In one embodiment, the perforating charges are linked together by a detonating cord 416 which is attached to a detonator 418 . In one embodiment, when the detonator 418 is detonated, the detonating cord 416 links the explosive event to all the perforating charges 402 , 404 , 406 , 408 , 410 , 412 , 414 , detonating them simultaneously. In one embodiment, a select fire sub 130 , 132 , 134 , 135 containing a single pressure activated switch (“PAS”) 420 is attached to the lower portion of the perforating charge element 136 , 138 , 140 , 142 . In one embodiment, the select fire sub 130 , 132 , 134 , 135 defines the polarity of the voltage required to detonate the detonator in the perforating charge element above the select fire sub. Thus in one embodiment, referring to FIG. 2 , select fire sub 130 defines the polarity of perforating charge element 136 , select fire sub 132 defines the polarity of perforating charge element 138 , select fire sub 134 defines the polarity of perforating charge element 140 , and select fire sub 135 defines the polarity of perforating charge element 142 . In one embodiment not shown in FIG. 2 , the bottom-most perforating charge element 142 is not coupled to a select fire sub (i.e., select fire sub 135 is not present) and thus can be detonated by a voltage of either polarity.
One embodiment of a pressure activated switch 420 , shown in FIGS. 5-9 , includes a housing 502 that fits within a housing, not shown, for a select fire sub 130 , 132 , 134 , 135 . In one embodiment, O-rings 806 and 808 , not shown in FIG. 5 , 6 , or 7 but shown in FIGS. 8 and 9 , provide a seal between the housing 502 and the housing for the select fire sub 130 , 132 , 134 , 135 . In one embodiment, the housing 502 has a large opening 504 at one end and a small opening 506 at the other end. In one embodiment, a large chamber 508 extends from the large opening 504 to a shoulder 510 . In one embodiment, a small chamber 512 extends from the shoulder 510 to the small opening 506 .
In one embodiment, a piston housing 514 houses a piston 516 . In one embodiment, the piston housing 514 is cylindrical. In other embodiments (not shown), the piston housing 514 has other shapes, in which the cross-section of the piston housing 514 is square, rectangular, oval, or some other shape. In one embodiment, the piston housing 514 has an outside diameter that fits within the inside diameter of the large chamber 508 . In one embodiment, the piston 516 is cylindrical. In other embodiments (not shown), the piston 516 has other shapes, in which the cross-section of the piston 516 is square, rectangular, oval, or some other shape. In one embodiment, the piston 516 has an outside diameter that is substantially the same (i.e., with enough of a difference to allow for the insertion of O-rings 802 and 804 , not shown in FIG. 5 , 6 , or 7 but shown in FIGS. 8 and 9 ) as the small piston-receiving chamber 610 (described below). In one embodiment, the piston housing 514 and the piston 516 are made of polyether ether ketone (or “PEEK”). In one embodiment, the piston includes O-rings 802 and 804 , not shown in FIG. 5 , 6 , or 7 but shown in FIGS. 8 and 9 , that provide a seal between the piston 516 and the piston housing 514 .
The piston housing 514 , shown in more detail in FIG. 6 , has a large contact-housing-receiving opening 602 and a small piston-receiving opening 604 . A large contact-housing-receiving chamber 606 extends from the large contact-housing-receiving opening 602 to a piston-housing shoulder 608 . A small piston-receiving chamber 610 extends from the piston-housing shoulder 608 to the small piston-receiving opening 604 .
In one embodiment, the piston housing 514 and the piston 516 are made of a non-conductive material. In one embodiment, the piston housing 514 and the piston 516 are made of PEEK.
In one embodiment, an electrically conductive leaf spring 612 is embedded in the piston housing 514 at one end and has a securing bead 614 at the other end. In one embodiment, the spring 612 is made of an electrically conductive spring material, such as copper or bronze. In one embodiment, the spring 612 is a wire. In one embodiment, the spring 612 has a ribbon shape.
In one embodiment, the securing bead 614 is a ball of conductive material, such as copper or bronze, welded or soldered to the end of the spring 612 . In one embodiment, the securing bead 614 is formed from the spring 612 by, for example, flattening the end of a wire. In one embodiment, a hole is drilled or otherwise formed in the securing bead 614 to receive a pin as described below.
In one embodiment, a conductive bead contact 616 is coupled, e.g., using an adhesive, to a wall of the large contact-housing-receiving chamber 606 . In one embodiment, a hole is drilled or otherwise formed in the bead contact 616 to receive a pin as described below.
In one embodiment, the piston 516 has threads 618 at its threaded end 620 . In one embodiment, the threads 618 receive the stop 532 (not shown in FIG. 6 ). In one embodiment, a tip contact 622 extends from the threaded end 620 of the piston 516 . In one embodiment, a conductor 624 , such as a wire, extends from the tip contact 622 to a pin contact 626 . In one embodiment, the piston housing 614 has holes 628 , 630 , 632 , and 634 drilled through from the outer circumference of the piston housing 614 to the large contact-housing-receiving chamber 606 . In one embodiment, hole 628 is substantially (i.e., within 10 degrees) collinear with hole 630 and hole 632 is substantially (i.e., within 10 degrees) collinear with hole 634 . In one embodiment, piston 516 includes holes 636 and 638 that are substantially (i.e., within 10 degrees) perpendicular to a longitudinal axis of the piston 516 and are spaced apart by substantially (i.e., within 1 millimeter) the same amount as holes 628 and 632 and holes 630 and 634 . In one embodiment, the piston 516 can be rotated so that hole 636 is substantially (i.e., within 10 degrees) collinear with holes 628 and 630 and hole 638 is substantially (i.e., within 10 degrees) collinear with holes 632 and 634 .
In one embodiment, the hole in bead contact 616 is alignable with hole 634 .
In one embodiment, a trigger pin 640 (represented by a hidden line) passes through hole 628 (which is not distinguished in FIG. 6 from the hidden line representing the trigger pin 640 ), a portion of the large contact-housing-receiving chamber 606 above (as seen in FIG. 6 ) the piston 516 , hole 636 (which is not distinguished in FIG. 6 from the hidden line representing the trigger pin 640 ), a portion of the large contact-housing-receiving chamber 606 below (as seen in FIG. 6 ) the piston 516 , the securing bead 614 and hole 630 (which is not distinguished in FIG. 6 from the hidden line representing the trigger pin 640 ). In one embodiment, the spring 612 is deflected from a position in which it is relaxed into the position shown in FIG. 6 , in which the spring 612 is in tension and is urging the securing bead 614 toward the large contact-housing-receiving opening 602 . In one embodiment, the securing bead 614 , which is held in position by the trigger pin 640 , keeps the spring 612 in tension.
In one embodiment, when the spring bead 614 is in the position shown in FIG. 6 it is in electrical contact with the bead contact 616 . In one embodiment (not shown), the bead contact 616 includes a geometrically-shaped object (i.e., a cube, sphere, cone, ovoid, cylinder, parallelpiped, etc., or variations on those shapes) that is projected from the surface of the bead contact 616 by a captive spring imbedded in the surface of the bead contact 616 and can be pressed into the surface of the bead contact 616 by the spring bead 614 while maintaining contact with the spring bead 614 . In one embodiment, the captive spring is conductive and provides an electrical connection to the spring bead 614 and the spring 612 .
In one embodiment, a conductive pin 642 (represented by a hidden line) passes through hole 632 (which is not distinguished in FIG. 6 from the hidden line representing the conductive pin 642 ), a portion of the large contact-housing-receiving chamber 606 above (as seen in FIG. 6 ) the piston 516 , hole 638 (which is not distinguished in FIG. 6 from the hidden line representing the conductive pin 642 ), a portion of the large contact-housing-receiving chamber 606 below (as seen in FIG. 6 ) the piston 516 , the hole in the bead contact 616 and hole 634 (which is not distinguished in FIG. 6 from the hidden line representing the conductive pin 642 ). In one embodiment, as conductive pin 642 passes through hole 638 it makes electrical contact with pin contact 626 and with bead contact 616 . Thus, in the configuration shown in FIG. 6 , tip contact 622 is electrically coupled to spring 612 through a pin conductor 624 , pin 642 , bead contact 616 , and securing bead 614 .
In one embodiment, the piston 516 has a pinning portion 644 that is the portion of the piston that extends into the large contact-housing-receiving chamber 606 and is pierced by the trigger pin 640 and the conductive pin 642 and a contact portion 646 that includes the portion of the piston that extends outside the piston housing 514 , including the threaded end 622 of the piston 516 . In one embodiment, the pinning portion 644 and the contact portion 646 are adjacent to each other. In one embodiment, there is a portion of the piston 516 between the pinning portion 644 and the contact portion 646 .
Returning to FIG. 5 , in one embodiment, a contact housing 518 includes a first contact 520 and a second contact 522 . In one embodiment, the first contact 520 and second contact 522 are half-circles or half-ovals of spring material as shown in FIG. 5 . In one embodiment (not shown), the first contact 520 and the second contact 522 are geometrically-shaped objects (i.e., cubes, spheres, cones, ovoids, cylinders, parallelpipeds, etc., or variations on those shapes) that are projected from the surface of the contact housing 518 by captive springs imbedded in the surface of the contact housing 518 and can be pressed into the surface of the contact housing 518 while maintaining contact with the item exerting the pressure. In one embodiment, the captive springs are conductive and provide an electrical connection to the first contact 520 and the second contact 522 .
In one embodiment, a first contact conductor 524 , such as a wire, provides an electrical path from the first contact 520 to the rear of the pressure activated switch 420 . In one embodiment, a second contact conductor 526 , such as a wire, provides an electrical path from the second contact 522 to the rear of the pressure activated switch 420 . In one embodiment, the contact housing 518 is cylindrical and has an outside diameter that fits within the piston housing 514 . In one embodiment, a contact housing shoulder 528 and contact housing shelf 530 are sized so that the contact housing shelf 530 fits within the large contract-housing-receiving chamber 606 and the contact housing 518 can be inserted into the piston housing 514 far enough so that the first contact 520 makes contact with the spring 612 but the second contact 522 does not make contact with the spring 612 . This can be seen in FIG. 7 , which shows an embodiment of an assembled version of the pressure activated switch 420 . In one embodiment, the first contact 520 is in contact with spring 612 but there is a gap 702 between second contact 522 and spring 612 . In the configuration shown in FIG. 7 , there is an electrical connection between conductor 524 and spring 612 through first contact 520 but no electrical connection between spring 612 and second contact 522 .
In one embodiment, the contact housing 518 is made of a non-conductive material. In one embodiment, the contact housing 518 is made of PEEK.
Returning to FIG. 5 , a threaded stop 532 attaches to the threaded end 620 of the piston 516 via threads 618 (see also FIG. 6 ). In one embodiment, a cap 534 , which in some embodiments is threaded, and a wave washer 536 hold the contact housing 518 in place inside the housing 502 .
In one embodiment, the assembly of the pressure activated switch begins by assembling the piston 515 , pins 640 and 642 , and spring 612 as shown in FIG. 6 . In one embodiment, this assembly is inserted into the housing 502 , with the tip contact 622 and the threaded end 620 of the piston 516 passing through the small opening 506 in the housing 502 . The stop 532 is then screwed on to the threaded end 620 of the piston 516 where it acts to prevent the piston 516 from moving into the piston housing 514 beyond the point where the stop 532 engages the piston housing 514 . In one embodiment, the cap 534 and wave washer 536 secure the contact housing 518 within the housing 502 .
As can be seen in the cross-sectional view of one embodiment of the pressure activated switch 420 in FIG. 8 , while the piston 516 is not restricted in movement by the piston housing 514 (except for the action of the O-rings 802 and 804 which provide a seal between the piston 516 and the housing 502 ), the trigger pin 640 and conductive pin 642 restrict the movement of the piston 516 within the piston housing 514 and the housing 502 . If, in one embodiment, enough force (“F” in FIG. 8 ) is exerted on the piston 516 , the trigger pin 640 and the conductive pin 641 will break. This is shown in FIG. 9 , which shows that the piston 516 has moved into the piston housing 514 and has broken the trigger pin 640 and the conductive pin 641 (represented by broken pieces 902 and 904 ). In one embodiment, this will free the securing bead 614 and allow the spring 612 to relax into the state shown in FIG. 9 in which the spring 612 completes an electrical circuit between conductor 524 and conductor 526 . In one embodiment, increases in the force F caused by the elevated temperatures at depth in an oil well are offset by increased pressure in the large contact-housing-receiving chamber 606 caused by the elevated temperatures.
In one embodiment, the pressure activated switch 420 shown in FIGS. 5-9 is “actuated,” as that word is used in this application, when the transition from the state of the pressure activated switch 420 shown in FIG. 8 (the “first state”) to the state of the pressure activated switch shown in FIG. 9 (the “second state”). In the first state, there is no electrical connection between first contact conductor 524 and second contact conductor 526 . In the second state, there is an electrical connection between first contact conductor 524 and second contact conductor 526 . In the first state, there is an electrical connection between the first contact conductor 524 and the tip contact 622 . In the second state, there is no electrical connection between the first contact conductor 524 and the tip contact 622 .
In one embodiment, O-rings 806 and 808 provide a seal between the housing 502 and a select fire sub housing (not shown). In one embodiment, a diode 810 determines the polarity of current that can flow through the circuit formed by conductor 524 , first contact 520 , spring 612 , second contact 522 , and conductor 526 . In one embodiment, with the diode 810 arranged as shown in FIGS. 8 and 9 , current can flow in conductor 524 and out conductor 526 . In an embodiment that is not shown in which the polarity of the diode 810 is reversed, current can flow in conductor 526 and out conductor 524 .
In one embodiment, the diode 810 is inside or attached to the contact housing 518 . In one embodiment, the diode 810 is outside the contact housing 518 and is attached to the select fire sub 420 in another way.
In one embodiment, the amount of force F required to break the trigger pin 640 and the conductive pin 642 is determined by the following equation:
F=A×P=T
where:
A is the cross-sectional area of the piston 516 ,
P is the pressure exerted on the piston in the direction of Force F in FIG. 8 (P out ) minus the pressure inside the piston housing 514 (P in ), i.e., P=P out −P in , and
T is the combined tensile breaking strength of the trigger pin 640 and the conductive pin 642 , where tensile breaking strength is the stress required to cause a break.
In one embodiment, the conductive pin 642 is not secured to the piston housing 514 so that a trigger-pin-breaking pressure differential, P trigger , generating a force F trigger , needs to be only sufficient to break the trigger pin 640 . In that case, T is the tensile breaking strength of the trigger pin 640 . In an embodiment in which both the conductive pin 642 and the trigger pin 640 are present, a two-pin-breaking pressure differential, P two-pin , generating a force F two-pin , needs to be sufficient to break both pins.
In one embodiment, the combined tensile breaking strength of the trigger pin 640 and the conductive pin 642 is between 400 and 600 pounds per square inch. In one embodiment, the combined tensile breaking strength of the trigger pin 640 and the conductive pin 642 is between 300 and 800 pounds per square inch. In one embodiment, the combined tensile breaking strength of the trigger pin 640 and the conductive pin 642 is between 200 and 1000 pounds per square inch.
In one embodiment, the trigger pin is non-conductive. In one embodiment, the trigger pin 640 is made of plastic, such as PEEK. In one embodiment, the trigger pin 640 is made of glass. In one embodiment, the trigger pin 640 is made of a ceramic material. In one embodiment, the trigger pin 640 is conductive. In one embodiment, the trigger pin 640 is a thin gauge wire (e.g., AWG 28 or higher) made of metal such as copper or a copper alloy. If the trigger pin 640 is conductive, in one embodiment the trigger pin 640 is installed so that it does not touch or make electrical contact with housing 502 .
In one embodiment, the conductive pin 642 is a thin gauge wire (i.e., AWG 28 or higher) made of metal such as copper or a copper alloy.
In one embodiment, the cross-section of the piston 526 is a disk measuring 0.5 inches in diameter, in which case its cross-sectional area is 0.196 inches. If the differential pressure across the piston is 1000 psi, the force F exerted on pins 640 and 642 would be 196 pounds. If the pins are made to break at a tensile force of 100 pounds, a differential pressure of approximately 510 psi (producing a force F of approximately 100 pounds) would be sufficient to break them. Such pressures are common in oil wells deeper than approximately 1500 feet. In one embodiment, for shallower wells in which the pressure is less, the pins are designed to break at lower forces. Similarly, in one embodiment, for deeper wells in which the pressure is greater, the pins may be designed to break at higher forces.
FIGS. 10 , 11 , and 12 are schematic diagrams of a portion of perforation apparatus 122 . Only perforating guns 142 , 138 , and 140 and select fire subs 134 and 132 are illustrated. It will be understood that the perforation apparatus 122 can include any number of perforating guns and any number of select fire subs by repeating the arrangement shown in FIG. 10 . Select fire sub 134 provides the switching for perforating gun 140 and select fire sub 132 provides the switching for perforating gun 138 . In one embodiment, select fire subs 134 and 132 have the elements illustrated above in FIGS. 5-9 . In the discussion of FIGS. 10 and 11 to follow those elements will be referred to by the select fire sub reference number (i.e., 132 or 134 ) followed by the element number. For example, the first contact (element 520 in FIGS. 5 , 7 , 8 , and 9 ) in select fire sub 132 will be referred to as first contact 132 / 520 . In one embodiment, there is no select fire sub associated with perforating gun 142 , which means that the detonator 1010 of perforating gun 142 is electrically coupled to pin 134 / 622 by way of a conducting wire and a diode 1008 . A diode 1008 assures that perforating gun 142 is fired with a selected polarity.
As can be seen in FIG. 10 , in one embodiment, a power line 1002 enters at the top of the apparatus. In one embodiment, the power line 1002 is coupled to a power line that flows through other perforating guns, other select fire subs, a CCL, a gamma ray correlator, and other equipment higher (i.e. closer to the earth's surface 104 ) than the equipment shown in FIGS. 10 , 11 , and 12 . In one embodiment, the power line 1002 is coupled to a pass-through line 1004 in perforating gun 138 which passes any voltage present on the pass-through line 1004 to the first contact conductor 132 / 524 of select fire sub 132 . In one embodiment, the first contact conductor 132 / 524 is coupled to the first contact 132 / 520 which is connected to the spring 132 / 612 . In one embodiment, the spring 132 / 612 is in its deflected state in which it is under tension. In one embodiment, the securing bead 132 / 614 at the end of the spring 132 / 612 is in contact with the bead contact 132 / 616 . In one embodiment, the bead contact 132 / 616 provides an electrical connection to the tip contact 132 / 622 through conductive pin 132 / 642 and pin conductor 132 / 624 .
In one embodiment, the tip contact 132 / 622 is electrically coupled to a pass-through line 1006 in perforating gun 140 which passes any voltage present on the pass-through line 1006 to the first contact conductor 134 / 254 of select fire sub 134 . In one embodiment, the first contact conductor 134 / 524 is coupled to the first contact 134 / 520 which is connected to the spring 134 / 612 . In one embodiment, the spring 134 / 612 is in its deflected state in which it is under tension. In one embodiment, the securing bead 134 / 614 at the end of the spring 134 / 612 is in contact with the bead contact 134 / 616 . In one embodiment, the bead contact 134 / 616 provides an electrical connection to the tip contact 134 / 622 through conductive pin 134 / 642 and pin conductor 134 / 624 .
In one embodiment, the tip contact 134 / 622 is coupled to the cathode of diode 1008 . The anode of diode 1008 is coupled to a detonator 1010 , which is coupled to one or more perforating charges 1012 (i.e., such as perforating charges 402 , 404 , 406 , 408 , 410 , 412 , and 414 shown in FIG. 4 ) through a detonating cord 1014 . The other electrical contact of the detonator 1010 is coupled to the housing of perforating gun 142 , which serves as a ground.
In one embodiment, with the perforation apparatus 122 configured as shown in FIG. 10 , any voltage or power applied to the power line 1002 will be applied to the cathode of diode 1008 . In one embodiment, the detonators on the other two perforating guns 138 and 140 , i.e. detonators 1016 and 1018 , are protected from detonation because the springs 132 / 612 and 134 / 612 are in their deflected positions which means there is no connection between the detonators 1016 and 1018 and the power line 1002 .
In one embodiment, a negative voltage is applied to power line 1002 and, through the connections described above, to the cathode of diode 1008 . The same negative voltage, minus a diode drop across diode 1008 , appears at the detonator 1010 causing it to detonate. That detonation causes perforating charge 1012 to explode.
The result of the explosion is shown in FIG. 11 . All or most of the components of the perforating gun 142 have been destroyed and a hole 1102 has been blasted in the housing of perforating gun 142 exposing piston 134 / 516 to fluids from the borehole. Fluids from the borehole (such as formation fluids or drilling mud) enter perforating gun 142 through hole 1102 . These fluids exert pressure on piston 134 / 516 causing it to move into the piston housing 134 / 514 . This movement breaks the conductive pin 134 / 642 and the trigger pin 134 / 640 . The latter action releases the securing bead 134 / 614 and allows the spring 134 / 612 to move to its relaxed position against the second contact 134 / 522 .
In this configuration, the perforating gun 140 is armed to fire. In one embodiment, the string of connections from the power line 1002 is the same as described above until it reaches the spring 134 / 612 . In one embodiment, the spring 134 / 612 is in its relaxed position and is in electrical contact with the second contact 134 / 522 . In one embodiment, the second contact 134 / 522 is coupled to the anode of a diode 134 / 810 . In one embodiment, the cathode of the diode is coupled to detonator 1018 in perforating gun 140 , which is coupled one or more perforating charges 1106 (i.e., such as perforating charges 402 , 404 , 406 , 408 , 410 , 412 , and 414 shown in FIG. 4 ) through a detonating cord 1108 .
In one embodiment, with the perforation apparatus configured as shown in FIG. 11 any voltage or power applied to the power line 1002 will be applied to the cathode of diode 134 / 810 . In one embodiment, the detonator on perforating gun 138 , i.e. detonator 1016 , is protected from detonation because the spring 132 / 612 is in its deflected position which means there is no connection between the detonator 1016 and the power line 1002 .
In one embodiment, a positive voltage is applied to power line 1002 and, through the connections described above, to the anode of diode 134 / 810 . In one embodiment, the same positive voltage, minus a diode drop across diode 134 / 810 , appears at the detonator 1018 causing it to detonate. In one embodiment, that detonation causes perforating charge 1106 to explode.
The result of the explosion is shown in FIG. 12 . All or most of the components of the perforating gun 140 have been destroyed and a hole 1202 has been blasted in the housing of perforating gun 140 exposing piston 134 / 516 to fluids from the borehole. Fluids from the borehole (such as formation fluids or drilling mud) enter perforating gun 140 through hole 1202 . These fluids exert pressure on piston 132 / 516 causing it to move into the piston housing 132 / 514 . This movement breaks the conductive pin 132 / 642 and the trigger pin 132 / 640 . The latter action releases the securing bead 132 / 614 and allows the spring 132 / 612 to move to its relaxed position against the second contact 132 / 522 .
In this configuration, the perforating gun 138 is armed to fire. In one embodiment, the string of connections from the power line 1002 is the same as described above until it reaches the spring 132 / 612 . In one embodiment, the spring 132 / 612 is in its relaxed position and is in electrical contact with the second contact 132 / 522 . In one embodiment, the second contact 132 / 522 is coupled to the cathode of a diode 132 / 810 . In one embodiment, the anode of the diode 132 / 810 is coupled to detonator 1016 in perforating gun 138 , which is coupled one or more perforating charges 1204 (i.e., such as perforating charges 402 , 404 , 406 , 408 , 410 , 412 , and 414 shown in FIG. 4 ) through a detonating cord 1206 .
In one embodiment, with the perforation apparatus configured as shown in FIG. 12 any voltage or power applied to the power line 1002 will be applied to the cathode of diode 132 / 810 . In one embodiment, a negative voltage is applied to power line 1002 and, through the connections described above, to the cathode of diode 132 / 810 . In one embodiment, the same negative voltage, minus a diode drop across diode 132 / 810 , appears at the detonator 1016 causing it to detonate. In one embodiment, that detonation causes perforating charge 1204 to explode.
In one embodiment, the polarity of the diodes 1008 , 134 / 810 , and 132 / 810 are chosen so that alternating positive and negative voltages on the power line 1002 are required to detonate alternate perforating guns. That is, a negative voltage on the power line 1002 is required to detonate perforating charge 1012 as dictated by diode 1008 , a positive voltage on the power line 1002 is required to detonate perforating charge 1106 as dictated by diode 134 / 810 , and a negative voltage on the power line 1002 is required to detonate perforating charge 1204 as dictated by diode 132 / 810 .
In one embodiment, the perforating system 122 is controlled by software in the form of a computer program on a computer readable media 1305 , such as a CD, a DVD, a portable hard drive or other portable memory, as shown in FIG. 13 . In one embodiment, a processor 1310 , which may be the same as or included in the firing panel 106 or may be located with the perforation apparatus 122 , reads the computer program from the computer readable media 1305 through an input/output device 1315 and stores it in a memory 1320 where it is prepared for execution through compiling and linking, if necessary, and then executed. In one embodiment, the system accepts inputs through an input/output device 1315 , such as a keyboard or keypad, and provides outputs through an input/output device 1315 , such as a monitor or printer. In one embodiment, the system stores the results of calculations in memory 1320 or modifies such calculations that already exist in memory 1320 .
In one embodiment, the results of calculations that reside in memory 1320 are made available through a network 1325 to a remote real time operating center 1330 . In one embodiment, the remote real time operating center 1330 makes the results of calculations available through a network 1335 to help in the planning of oil wells 1340 or in the drilling of oil wells 1340 .
The word “coupled” herein means a direct connection or an indirect connection.
The text above describes one or more specific embodiments of a broader invention. The invention also is carried out in a variety of alternate embodiments and thus is not limited to those described here. The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.
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A first end of a conductive spring is embedded in a wall of a large chamber of a piston housing. The spring is held in tension by a second end of the spring being pinned against a bead contact by a trigger pin. The diameter of the piston and a tensile breaking strength of the trigger pin are selected so that the trigger pin is breakable and the tension in the spring is releasable upon the presence of a predetermined pressure difference between a pressure on the contact side of the piston and a pressure on the pinning side of the piston. Release of tension in the spring closes an electrical circuit.
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FIELD OF THE INVENTION
This invention relates to a web wrap apparatus with a brake device acted upon by a web pulled by an article being wrapped, and having a feeder to transport the web.
BACKGROUND OF THE INVENTION
EP 2 044 830 A1 discloses a wrapping means tensioning device having a control arm and a brake arm, both being pivotally connected to one another and pivoting as a unit about an axis. The brake arm presses on a net roll to achieve a certain tension in the net during the wrapping process. The free end of the control arm is applied by the net and is deflected by it even more as the tension in the net increases. As a result, the pressing force onto the web roll will disappear, once the net is cut.
The problem this invention is based on is seen in the fact, that the net roll continues with its rotation even after the net is cut, which results in net being wound off the roll and being apt to create a net curl.
SUMMARY OF THE INVENTION
According to the invention the brake arm rests against the roll of web, even when the latter is cut and the brake device is no longer activated by the web. The force applied by the brake device does not necessarily need to remain at the highest level, but be at least sufficient to hinder the web roll from further rolling. The retainer may be a mechanical lock as well as a powered device like a motor, a solenoid activated clutch, lock, etc. The feeder may be of any type, like a duckbill, feed roller(s), feeder comb, etc. The movement of the feeder to start the feeding process will be used to unlock the brake device and release the brake. In case the feeder has a built-in reservoir for the web, the brake may open later; the brake may open earlier as well, provided the web roll has stopped rolling.
If the retainer is in the form of a multi-position ratchet, one part of it being located on the brake device and one part on the feeder, the brake device may be locked not just in one position, but at the position of maximum brake force, which has been achieved by the brake device. The ratchet may be a toothed rod, arc, etc. and a small driver entering the teeth.
In order to release the brake device, a lever, linkage, Bowden cable or the like may be used, which is activated by a movement of the feeder. A spring—mechanical or pneumatic—may force the lever into the locked position.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings wherein:
FIG. 1 is a round baler in schematic side view provided with a web wrap apparatus;
FIG. 2 is the web wrap apparatus of FIG. 1 depicted in a waiting position;
FIG. 3 is the web wrap apparatus of FIG. 1 depicted in a waiting position;
FIG. 4 is the web wrap apparatus of FIG. 1 depicted in a feeding operation on the way back to the waiting position; and
FIG. 5 is the web wrap apparatus of FIG. 1 depicted in a partly retracted position acting on a lever.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows around baler 10 , which has a chassis 12 , a pick-up 14 , a bale chamber 16 , a web wrap apparatus 18 , an axle with wheels 20 , a tongue 22 and baling elements 24 .
The round baler 10 shown is of an ordinary fixed chamber design, but could also be a variable chamber design.
The chassis 12 rests on the axle with the wheels 20 , carries the pick-up 14 and can be connected to a tractor or the like by way of the tongue 22 . The chassis 12 has one or multiple part side walls 26 , which are spaced apart from one another to receive between them the bale chamber 16 , all or part of the web wrap apparatus 18 and the baling elements 24 .
The pick-up 14 picks up crop from the ground and delivers it to the bale chamber 16 through a crop inlet 28 between the baling elements 24 .
The bale chamber 16 is covered substantially by the baling elements 24 on the circumference and by the side walls 26 on the face sides. Beside the crop inlet 28 a gap 30 is provided between the baling elements 24 , through which web 32 may be fed into the bale chamber 16 . The bale chamber 16 serves to form a cylindrical bale of hay, straw or the like, which will be covered by the web 32 of plastic, net paper or the like. The baling elements 24 in this embodiment are in the form of steel rolls rotatably received in the sidewalls 26 and extending perpendicular to them. These baling elements 24 are arranged substantially on a circle.
The web wrap apparatus 18 is visible in more detail in FIG. 2 and contains among other things a housing 34 , a motion element 36 , a brake device 38 , a feeder 40 and a separator and an actuating mechanism (not shown). The latter are described in more detail in European Patent Appl. No. 09155481.6 filed on 18 Mar. 2009.
The housing 34 is located in the front upper part of the round baler 10 between or substantially between the side walls 26 and has a rear wall 46 and a left and a right wall 48 connected to one another and suitable to be connected to the side walls 26 . Depending on the width of the web 32 , the housing 34 and the entire web wrap apparatus 18 may extend beyond the side walls 26 . The rear wall 46 may be of a material, or may have a layer, which creates a certain friction, which will have an influence on the rolling resistance of a roll 50 of the web 32 . The housing 34 may be used to attach all components and parts of the web wrap apparatus 18 to it to form an autonomous unit. The right and left walls 48 extend to the rear towards the bale chamber 16 as needed to take up some of the parts described later.
The motion element 36 is formed by a roll 52 , preferably rubber coated, which is journalled rotatably about a horizontal axis in the side walls 48 and which is located such that the roll 50 of the web 32 can rest on it. As is known in the art, but not shown here, the roll 52 is connected via a chain drive and a free-wheel to the baling elements 24 such that it must rotate slower than the baling elements 24 .
The brake device 38 substantially has a control arm 58 and a brake arm 60 connected together on a shaft 62 to pivot about a horizontal axis of the latter. A gas spring (not shown) may be connected to the shaft 62 via an arm (not shown) to assist or resist the rotational movement of the shaft 62 . It is the purpose of the brake device 38 to exert a certain pressure onto the roll 50 of the web 32 to assure a sufficient tension in it, when it is wrapped onto a bale (not shown). The shaft 62 is located at about the same height as the roll 52 and at a certain distance to it forwardly. The control arm 58 extends underneath the roll 52 and from a location rearward of the roll 52 to the shaft 62 and ends at about the center of the roll 52 . The control arm 58 has an idler bar 68 or an angle extending parallel to the axis of the roll 52 between the side walls 48 of the web wrap apparatus 18 . The brake arm 60 extends from the shaft 62 to a location above a completely wrapped roll 50 of the web 32 and has a cross element 70 designed to push onto the circumferential surface of the roll 50 , thereby pressing the roll 50 against the rear wall 46 and creating the desired rolling resistance. As is apparent from the drawing, a downward, counter-clockwise movement of the control arm 58 will provoke a counter-clockwise movement of the brake arm 60 upon the roll 50 of the web 32 .
The feeder 40 in this embodiment is formed as a so-called duckbill, which however is not mandatory; it could be any other moving part pulling the web 32 from the roll 50 and feeding it into the bale chamber 16 through the gap 30 . The feeder 40 is composed of struts 72 on each side holding between them a carrier 74 in the form of a mouthpiece at a lower end thereof, two vertically distant bearings 76 . The carrier 74 as such is known and has two opposite plates biased onto one another to clamp a piece of the web 32 and move it rearward. An upper link 82 and a lower link 84 forming part of a parallelogram linkage are connected with one end area to the bearings 76 and with their other end areas to the bearings 86 on the side walls 48 of the web wrap apparatus 18 being offset horizontally as well as vertically; lines through the bearings 76 at one end and the bearings 86 at the other end do not run parallel but divergently. The upper link 82 has an eye 88 on its upper side or a bore or the like useful to provide a connection to an actuator 110 such as an electric or hydraulic motor. An idler element 116 is connected to and connects the struts 72 on both sides. The idler element 116 assists in feeding the web 32 in a proper way into the carrier 74 . The idler element 116 may consist of a simple bar or shaft.
The motor 110 , which may be actuated electrically, hydraulically or pneumatically is connected with one side to the side walls 48 of the web wrap apparatus 18 or any other stationary feature of the chassis 12 and with the other side to the eye 88 on the upper link 82 .
As is best seen in FIG. 3 a lever 118 is provided, with which an upper end area is journalled in a bearing 120 (see FIG. 2 ) in the wall 48 and which in its lower end area has a longitudinal slot 122 extending substantially on a circle about the bearing 120 . Furthermore the lever 118 has a contact area 124 on the rear side and an aperture 126 . The contact area 124 may be an angle or flat steel welded to the lever 118 and extending perpendicular to it. The lever 118 extends substantially vertically.
At the wall 48 a guide 128 is provided, which in a simple manner consists of a bolt, a bushing, a rod or the like, protruding through the slot 122 to limit the pivot movement of the lever 118 about the bearing 120 .
A retainer 130 in the form of a ratchet is provided in an area, where the control 58 and the lever 118 make contact with one another. The retainer 130 has a first part 132 in the form of a toothed bar, cam or the like, wherein the teeth face towards the lever 118 . The teeth are oriented and slanted downwardly to provide a good grip. A second part 134 of the retainer 130 is provided at the end of the lever 118 and has the form of a tooth, which may enter the space between two teeth on the first part 132 . This second part 134 is oriented upwardly to engage securely in the first part 132 .
Finally a spring 136 is installed between the aperture 126 and a location at the wall 48 . The spring 136 , which in this case is a coil tension spring, can be of any kind but needs to bias the lever 118 in a mating position of the first and the second part 132 , 134 , respectively.
While on either side one lever 118 , one retainer 130 and one spring 136 would be sufficient it would be beneficial to have such a set on both sides of the round baler 10 .
Based on this structural description the function is described as follows starting from a state shown in FIG. 2 , in which the web wrap apparatus 18 waits to be operated. In a state as shown in FIG. 2 , the roll 50 with the web 32 is placed on the roll 52 and is secured in its position between the cross element 70 and the rear wall 46 . The feeder 40 is in a position remote from the gap 30 . The web 32 extends from the roll 50 , underneath the roll 52 over the idler bar 68 , through the carrier 74 , where it is clamped.
As soon as a manual or electrical signal is given to the actuating motor 110 to initiate wrapping the web 32 around a bale, the motor 110 is extended, thereby moving the feeder 40 downward and towards the gap 30 . Once the carrier 74 protrudes the gap 30 , the web portion hanging down from the carrier 74 is caught by the rotating bale and pulled from the roll 50 . Tension is created in the web 32 , since the roll 50 experiences friction on the wall 46 and since the roll 52 is hindered from free movement. FIG. 5 shows a situation, in which the motor 110 is retracted and thereby the feeder 40 is on its way back to a resting or home position.
FIG. 3 shows a situation, in which both parts 132 , 134 are in a positive locking condition, whereas the control arm 58 is in a low position, which corresponds to the lowest position reached in the preceding wrapping cycle. The struts 72 are distant from the contact area 124 of the lever 118 . Due to the connection between the control arm 58 and the brake arm 60 , pivoting about the shaft 62 , this location of the control arm 58 will exert considerable pressure on the web roll 50 through the contact with the cross member 70 .
FIG. 2 shows the feeder 40 on its way to the gap 30 by pivoting about the bearings 86 . During this downward movement the upper end of the struts 72 will hit the lever 118 in the contact area 124 and will push the lever 118 forward. The clockwise movement will disconnect the two parts 132 , 134 of the retainer 130 and the assembly of the control arm 58 and the brake arm 60 is free to pivot upwardly either by the inherent bending forces in the brake device 38 and/or by the gas spring acting between the shaft 62 and the brake arm 60 . The result is the position shown in FIG. 2 .
FIG. 4 shows a situation, in which the web 32 is pulled by the bale in the bale chamber 16 and due to the tension in the web 32 the idler bar 68 is pushed down. Since at the same time the feeder 40 returns to its home position, the retainer 130 is disconnected, which at that time is no problem, since the tension in the web 32 still endures.
In FIG. 5 the feeder 40 has almost passed the lever 118 , which then will again connect the two parts 132 , 134 of the retainer 130 by virtue of the spring 136 . When the web 32 is separated by a separator (not shown), the retainer 130 is locked and remains locked, until the wrapping cycle starts from the beginning.
Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.
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A web wrap apparatus is provided and has a brake device that exerts pressure on a roll of a web material. In order to exert pressure even after the web material is cut, the brake device is locked by a retainer once the web is separated and is released by a feeder, when moving from a home position to a web feed position.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 11/716,050, filed Mar. 9, 2007, which is a divisional of U.S. application Ser. No. 11/417,113, filed May 4, 2006, which claims the benefit of U.S. Provisional Application No. 60/667,825, filed on May 5, 2005. The entire teachings of the above application(s) are incorporated herein by reference.
GOVERNMENT SUPPORT
[0002] The invention of the present application was made using funds from the U.S. government. The U.S. government may therefore retain certain rights under the terms of grant 5K08-DK02815-04.
TECHNICAL FIELD OF THE INVENTION
[0003] This invention is related to the area of kidney disease. In particular, it relates to diagnosis and treatment and drug discovery for kidney disease.
BACKGROUND OF THE INVENTION
[0004] FSGS is a significant cause of end-stage renal disease world-wide and up to one-fifth of dialysis patients have this diagnosis (1, 2). The prevalence of FSGS is increasing yearly and the incidence is particularly high in the black population (1, 3). FSGS is a pathological entity in which the glomerulus is primarily targeted. Typical manifestations of FSGS include proteinuria, hypertension, renal insufficiency and eventual kidney failure. Our understanding of the pathogenesis of FSGS is incomplete and there are no consistently effective treatments.
[0005] Analysis of disease-causing mutations in hereditary FSGS and congenital nephrotic syndromes has provided striking new insights into the pathogenesis of nephrotic syndrome. The previous identification of at least three genes causing familial FSGS and hereditary nephrotic syndromes underscores the significant genetic heterogeneity in this disorder (4-6). These studies have highlighted the importance of abnormalities in the podocyte and the slit diaphragm of the glomerulus to the development of the severe proteinuria that characterizes the nephrotic syndrome.
[0006] Previously, we ascertained and characterized a large New Zealand family of British origin with autosomal dominant hereditary FSGS ( FIG. 4 ) ( 7 ). The character of the disease in this family is particularly aggressive. Affected individuals typically present with high-grade proteinuria in their 3 rd or 4 th decade and approximately 60% progress to end-stage renal disease (ESRD). The average time between initial presentation and the development of ESRD is 10 years. A genomic screen performed on this kindred localized the disease-causing mutation to chromosome 11q (8). However, this genomic region is very large and contains hundreds of genes.
[0007] There is a continuing need in the art to identify genes and proteins which are associated with or causative of kidney disease, so that they can be used to more accurately and effectively diagnose and treat kidney disease.
SUMMARY OF THE INVENTION
[0008] The present invention has many aspects. A first aspect of the invention is a cell-free preparation of a mutant TRPC6 protein comprising a glutamine at residue 112 of TRPC6.
[0009] Another aspect of the invention is a cell-free preparation of a polypeptide comprising at least six contiguous amino acid residues of a P112Q mutant of TRPC6, wherein the polypeptide comprises residue 112.
[0010] An additional aspect of the invention is a cell-free preparation of a polynucleotide which encodes a human TRPC6 polypeptide of at least six contiguous amino acid residues, said polypeptide comprising a P112Q substitution.
[0011] In one embodiment of the invention a cell culture comprising a human cell is provided. The human cell comprises a polynucleotide which encodes a human TRPC6 protein comprising a P112Q substitution
[0012] According to another aspect of the invention a cell-free preparation of an antisense polynucleotide is provided. The polynucleotide comprises at least 18 contiguous nucleotides which are complementary to a human TRPC6 coding sequence selected from the group consisting of wild-type and a P112Q mutant.
[0013] An additional embodiment of the invention provides a method of inhibiting TRPC6 channels in a kidney of a glomerulonephritis patient. An inhibitor of TRPC6 channels is administered to the patient. Calcium ion influx is thereby reduced.
[0014] Yet another embodiment of the invention provides a method of inhibiting expression of TRPC6 channels in the kidney of a glomerulonephritis patient. An antisense polynucleotide is administered to a kidney of the patient. Expression of TRPC6 channels is thereby inhibited. The antisense polynucleotide comprises at least 18 contiguous nucleotides which are complementary to a human TRPC6 coding sequence selected from the group consisting of wild-type and a P112Q mutant.
[0015] Still another aspect of the invention is a method of identifying a subject at increased risk of developing Focal and Segmental Glomerulosclerosis (FSGS). A sequence feature of a TRPC6 gene in a subject is determined. The determined sequence feature of the gene of the subject is compared to the sequence feature in a reference wild-type TPRC6 gene. The subject is identified as being at increased risk of developing FSGS if the sequence feature of the gene of the subject differs from the reference or if it matches a mutation associated with FSGS.
[0016] Another embodiment of the invention provides another method of identifying a person at increased risk of developing Focal and Segmental Glomerulosclerosis (FSGS). A sequence feature of a TRPC6 protein in a subject is determined. The determined sequence feature of the protein of the subject is compared to the sequence feature in a reference wild-type TPRC6 protein. The subject is identified as being at increased risk of developing FSGS if the sequence feature of the protein of the subject differs from the reference or if it matches a mutation associated with FSGS.
[0017] Another embodiment of the invention is a container comprising a set of primer pairs for amplifying all or part of TRPC6 sequences. The set comprises a pair which amplifies all or part of exon 2 sequences of TRPC6.
[0018] Still another aspect of the invention is a probe for detecting a C335A mutation. The probe comprises a single stranded or double stranded polynucleotide of at least 15 nucleotides which are complementary to a contiguous portion of a human TRPC6 gene which comprises nucleotide 335 of the coding sequence.
[0019] According to another embodiment of the invention a cell-free preparation of an antibody is provided. The antibody preferentially binds to a TRPC6 protein with a P112Q substitution relative to a TRPC6 protein with a proline at residue 112.
[0020] Another aspect of the invention is embodied by a method of screening for candidate agents useful for treating FSGS. A wild-type or mutant form of TRPC6 protein is contacted with a test substance. Activity of the form of TRPC6 protein is measured. A test substance is identified as a candidate agent for treating FSGS if it inhibits activity of the TRPC6 protein.
[0021] Another aspect of the invention is embodied by a method of screening for candidate agents useful for treating glomerulonephritis. A wild-type or mutant form of TRPC6 protein is contacted with a test substance. Activity of the form of TRPC6 protein is measured. A test substance is identified as a candidate agent for treating glomerulonephritis if it inhibits activity of the TRPC6 protein.
[0022] An additional embodiment of the invention is a method of classifying a patient with Focal and Segmental Glomerulosclerosis (FSGS). A sequence feature of a TRPC6 gene in a subject with FSGS is determined. The determined sequence feature of the gene of the subject is compared to the sequence feature in a reference wild-type TPRC6 gene. The subject is identified as having a TRPC6 mutation if the sequence feature of the gene of the subject differs from the sequence feature in the reference or if it matches a mutation associated with FSGS.
[0023] Still another embodiment of the invention is a method of classifying a patient with Focal and Segmental Glomerulosclerosis (FSGS). A sequence feature of a TRPC6 protein in a subject with FSGS is determined. The determined sequence feature of the gene of the subject is compared to the sequence feature in a reference wild-type TPRC6 protein. The subject is identified as having a TRPC6 mutation if the sequence feature of the protein of the subject differs from the sequence feature in the reference or if it matches a mutation associated with FSGS.
[0024] These and other embodiments which will be apparent to those of skill in the art upon reading the specification provide the art with reagents and methods for detection, diagnosis, therapy, prognosis, and drug screening pertaining to glomerulonephritis and FSGS.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1A-1B . ( FIG. 1 . A) Minimal candidate region (MCR) of FSGS on human chromosome 11q. The area of interest is flanked by markers D11S1876 and D11S1339. The genetic distance from the centromere (cent) was obtained from the website at UCSC Genome Browser: ucsc.edu. Black squares indicate common alleles among affected individuals. Light squares indicate recombination. Individual 165 is the parent of individual 9044. Individual 9014 provides an example of the ancestral affected haplotype. All individuals represented are affected. The MCR is defined by individual 9044. Microsatellite markers in bold indicate original flanking markers. Gray box indicates candidate gene region. tel=telomere. ( FIG. 1 . B) Sequence chromatogram of exon 2 of TRPC6. The arrows highlight the C/A mutation.
[0026] FIG. 2A-2F . Immunofluorescence staining and fluorescent in-situ hybridization of normal human renal cortical tissue for TRPC6. ( FIG. 2A ) Immunofluorescent staining of normal human renal cortical tissue with rabbit antibody against human TRPC6. In this representative photomicrograph, specific staining within a glomerulus (G) and the epithelium of surrounding tubules (T) is easily seen. ( FIG. 2B ) Negative control of an adjacent section also stained with the primary anti-TRPC6 antibody in the presence of the immunizing peptide. There is minimal non-specific staining Bars in panels A and B=25 μm. Fluorescent in situ hybridization (FISH) of TRPC6 mRNA in normal human renal cortex. ( FIG. 2C ) TRPC6 antisense probe generated from nucleotides 2301-3621 from TRPC6 mRNA [Accession number AJ006276]. ( FIG. 2D ) Hybridization with the corresponding TRPC6 sense probe. Scale bar=90 microns. ( FIG. 2E ) and ( FIG. 2F ) High power photomicrographs of the same sense and antisense probes. Scale bar=40 microns. Widespread expression of TRPC6 mRNA was detected throughout the kidney in both glomeruli and tubular epithelia. Background staining in panels D and F reflects autofluorescence from red blood cells trapped at the time of kidney harvest. Arrows highlight glomeruli. Asterisks are centered in renal tubules.
[0027] FIG. 3A-3D . The TRPC6 P112Q mutant enhances the influx of calcium into cells via DAG-mediated and receptor-operated pathways. ( FIG. 3A ) Intracellular calcium concentrations were measured after OAG perfusion. TRPC6 P112Q transfected cells had significantly higher calcium concentrations than cells transfected with WT TRPC6. The peak influx [Ca 2+ ]i is depicted in the bar graph below the tracing. ( FIG. 3B ) Angiotensin-II induced intracellular calcium concentrations were measured. The peak influx [Ca 2+ ]i is depicted in the bar graph below the tracing. Again, TRPC6 P112Q transfected cells had significantly higher calcium concentrations than cells transfected with WT TRPC6. Each trace represents the mean value derived from 15-20 cells in a single experiment, each experiment was replicated three times, with similar results. The error bars represent standard deviation. ( FIG. 3C ) Whole cell current recordings of HEK 293 cells expressing either WT TRPC6 or TRPC6 P112Q protein. Considerable inward currents in normal Na + extracellular solution were observed in WT TRPC6 cells. However, inward currents were significantly larger in TRPC6 P112Q cells. When cells were perfused with 100 μM UTP, even larger inward currents were obtained. Cells expressing TRPC6 P112Q mutation conducted 2-3 times more current than the WT TRPC6 expressing cells as depicted in the bar graph next to the current recordings. ( FIG. 3D ) Surface expression experiments in HEK 293 cells transfected with TRPC6 protein. Biotinylation was used to quantitate cell surface expression of TRPC6 proteins. Cells expressing TRPC6-V5 or TRPC6 P112Q -V5 were incubated with biotin-SS reagent followed by pull-down with streptaviden agarose beads. Immunoblotting with an anti-V5 antibody of surface and whole cell lysates demonstrate increased surface expression of the TRPC6 P112Q compared to wild-type TRPC6 protein. Immunoblotting with an anti-transferrin receptor antibody (TfR) is located in the middle row and shows no difference in the surface expression of the constitutively active plasma membrane receptor (95 kD band). Each experiment was replicated four times, with similar results. Densitometry measurement in relative units are depicted in the bar graph next to the immunoblot (the results from all four replicants are quantitated). The error bars represent standard error.
[0028] FIG. 4 . Simplified version of pedigree for family 6530. Apparent autosomal dominant inheritance. Family structures have been changed for anonymity (1).
Definition of Disease Status:
[0029] Affected—Family members who had a renal biopsy demonstrating FSGS without evidence of other systemic diseases that have been known to cause FSGS, were on dialysis or had undergone renal transplantation.
Probably affected—Greater than or equal to 3+-4+ proteinuria by qualitative urinalysis, in the absence of other systemic diseases likely to lead to proteinuria.
Unknown—Less than 1-2+ proteinuria or ≦500 mg of proteinuria on 24-hour urine collection.
Unaffected—If they had no detectable proteinuria on qualitative urinalysis or were unrelated married-in spouses.
[0030] FIG. 5 . Proline 112 is highly conserved in evolution and is present in TRPC protein homologs from Mus musculus, Rattus norvegicus, Drosophila melanogaster, Caenorhabditis elegans and Cavia porcellus (SEQ ID NOS: 1-6). The arrow indicates the mutated proline. Comparative alignments with the mouse, human and rat sequences indicate that a homolog of the TRPC protein family is also present in zebrafish ( Danio rerio ) and pufferfish ( Fugu rubripes ) and that this proline is also conserved in these organisms (see the world wide web site at ensembl.org). Within the TRPC family, TRPC3, -6 and -7 all contain the conserved proline. TRPC4 and -5 have an alanine at this position, which, like proline, is a non-polar amino acid, while TRPC1 has a tyrosine at this position. TRPC2 is a pseudogene in humans. Genebank Accession Numbers: TRPC6 Homo sapiens , NP — 004612; Mus musculus , Q61143; Rattus norvegicus , NP — 446011; Caenorhabditis elegans , NP — 498881; Drosophila melanogaster , NP — 476895 ; Cavia porcellus , CAC06051.
[0031] FIG. 6 . Western blot of protein extracts from HEK 293 cells transfected with empty vector (lane 1), TRPC6 P112Q (lane 2) or TRPC6 (lane3). Blots were incubated with specific antibodies against TRPC6 and actin. The immunoblot reveals three different bands and while there are different isoforms of TRPC6, there is evidence that this is glycosylation as TRPC6 is known to be heavily glycosylated (8).
[0032] FIG. 7 . OAG-stimulated barium transients were measured using the Fura-2 method in HEK293 cells transfected with WT TRPC6 (blue) or TRPC6P112Q (red). Fura fluorescence shifts in a similar pattern with barium and calcium, barium was used as a surrogate for calcium in these assays (9). As expected, OAG perfusion increased late barium transients in cells transfected with WT TRPC6. In contrast, barium influx was significantly enhanced in TRPC6P112Q-expressing cells exposed to OAG, reflecting dramatic exaggeration of intracellular cation concentration in cells expressing the mutant protein (Δ340/380 ratio TRPC6P112Q=1.30±0.7 vs. WT TRPC6=0.49±0.18; p=0.01). There are fluctuations of barium entry in the HEK 293 cells with the mutant construct. We postulate that this mutation causes disordered and dysregulated calcium entry. Y-axis is wavelength. The mean change in fluorescence is depicted by the bar graph. Error bars represent standard deviation.
[0033] FIG. 8 . Angiotensin II-induced barium transients were measured in HEK 293 cells transfected with AT1 receptor alone (green) or co-transfected with the AT1 receptor along with wild-type TRPC6 (blue) or TRPC6 P112Q (red). Upon exposure to angiotensin II, large barium transients were triggered in both WT- and TRPC6 P112Q -transfected cells and the amplitude of the initial barium signal tended to be higher in the TRPC6 P112Q cells. The Y-axis is wavelength. Moreover, the duration of the signal was prolonged in the TRPC6 P112Q cells (1054±282 seconds) compared with cells transfected with WT TRPC6 (271±121 seconds; p<0.01). The duration and amplitude are depicted in the bar graph below the tracing. Error bars represent standard deviation.
[0034] FIG. 9 . Table 1 showing primer sequences for TRPC6 (SEQ ID NO: 7-62).
[0035] FIG. 10 . Table 2 showing SNPs in mRNA.
[0036] FIG. 11 . Table 3 showing SNPs in gene.
DETAILED DESCRIPTION OF THE INVENTION
[0037] We have identified TRPC6 as a disease-gene causing hereditary FSGS. Because ion channels such as TRPC6 tend to be amenable to pharmacological manipulation, TRPC6 is identified as a useful therapeutic target in chronic kidney disease, including glomerulonephritis. Glomerulonephritis may be associated with any of the following conditions, without limitation: Focal Segmental Glomerulosclerosis (FSG), Goodpasture's syndrome, an IgA nephropathy, IgM mesangial proliferative glomerulonephritis, Lupus nephritis, Membranoproliferative glomerulonephritis I, Membranoproliferative glomerulonephritis II, Membranoproliferative glomerulonephritis III, post-streptococcal glomerulonephritis, rapidly progressive (crescentic) glomerulonephritis, membranous nephropathy, and diabetic nephropathy.
[0038] A cell-free preparation according to the present invention may comprise either polynucleotide or protein. Typically, the polynucleotide or protein will be extracted from the cells by breaking the cell membrane and optionally removing non-desired components. For example, proteins or nucleic acids can be removed if not desired using enzymatic degradation. Alternatively, desired proteins or nucleic acids can be purified using sequence-specific reagents, including but not limited to oligonucleotide probes, primers, and antibodies. Lysozyme and/or detergents and/or pressure can be used to break cells, for example. Techniques for isolating cell-free preparations are well known in the art, and any that are convenient can be used.
[0039] The P112Q mutant TRPC6 protein of the invention has a glutamine at residue 112 in place of the proline which is found in normal, non-affected humans. See SEQ ID NO: 63 to determine which residue is residue 112. See also SEQ ID NO: 65 which contains a P15S single nucleotide polymorphism at residue 15. Both of these are considered to be wild-type with respect to FSGS. Additional polymorphisms which do not affect calcium ion channel function, as described herein, may be present in addition to the P112Q substitution mutation. With respect to the TRPC6 gene, over 600 SNPs are known which do not affect the encoded protein. These include two synonymous SNPs at codons 904 and 561, as well as numerous SNPs in untranslated regions and in introns. See Tables 2 and 3. These, too, are considered wild-type with respect to FSGS.
[0040] Sequence features, according to the present invention, can be determined using any techniques which detect directly or indirectly a change in a protein or nucleic acid sequence. Thus, for example, if a mutation causes premature truncation, such a sequence feature can be detected by determining the size of the encoded mRNA or protein. Directly determining amino acid or nucleotide sequences can be used, and these techniques are well known in the art. Antibodies that are specific for a sequence feature can be used for probing mutant proteins. Probes and or primers that hybridize to wild-type or a particular mutation can be used. Any technique which detects such hybridization or the lack thereof can be used without limitation.
[0041] Polypeptides according to the present invention which contain residue 112 of TRPC6 protein can be used inter alia for raising antibodies. Such polypeptides are typically less than full-length, 931 residue proteins. Preferably such residues are at least 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 19, 21, 23, or 25 residues in length. As an example, if the polypeptide is 6 residues in length, than it can comprises residues 112-117, 111-116, 110-115, 109-114, 108-113, or 107-112. Sufficient residues are desired to form a good immunogen or blocking antigen for use in assays. It may be desirable to conjugate or genetically fuse additional sequences to the polypeptide, for example, to boost immunogenicity, to enhance purification, to facilitate production or expression, or to facilitate detection. Any sequences as are convenient may be used for these or other purposes. The size of these additional sequences may vary greatly, but typically will be at least 2, 4, 6, or 8 amino acid residues in length. The polypeptide may contain either proline (wild-type) or glutamine (mutant) residue at position 112.
[0042] While particular nucleotide sequences which are found in humans are disclosed herein (see, e.g., SEQ ID NO: 64 and the SNPs shown in Tables 2 and 3) any nucleotide sequences may be used which encode a desired form of TRPC6. Thus non-naturally occurring sequences may be used. These may be desirable, for example, to enhance expression in heterologous expression systems of polypeptides or proteins of TRPC6. Computer programs for generating degenerate coding sequences are available and can be used for this purpose. Pencil, paper, the genetic code, and a human hand can also be used to generate degenerate coding sequences. For production purposes, it may be desirable to genetically engineer a coding sequence of a TRPC6 protein or polypeptide into an expression vector. Such vectors will typically contain an origin of replication, either of viral or plasmid origin. Such polynucleotides and/or vectors can be replicated and/or expressed in cell culture. Preferably the cultures will be of mammalian cells, and more preferably of human cells. However, other cell types may be advantageous for production, including but not limited to yeast cells, insect cells, and avian cells.
[0043] Antisense constructs, antisense oligonucleotides, RNA interference constructs or siRNA duplex RNA molecules can be used to interfere with expression of TRPC6. Typically at least 15, 17, 18, 19, or 21 nucleotides of the complement of TRPC6 mRNA sequence are sufficient for an antisense molecule. Typically at least 18, 19, 21, 22, or 23 nucleotides of TRPC6 are sufficient for an RNA interference molecule. Preferably an RNA interference molecule will have a 2 nucleotide 3′ overhang. If the RNA interference molecule is expressed in a cell from a construct, for example from a hairpin molecule or from an inverted repeat of the desired TRPC6 sequence, then the endogenous cellular machinery will create the overhangs. siRNA molecules can be prepared by chemical synthesis, in vitro transcription, or digestion of long dsRNA by Rnase III or Dicer. These can be introduced into cells by transfection, electroporation, or other methods known in the art. See Hannon, G J, 2002, RNA Interference, Nature 418: 244-251; Bernstein E et al., 2002, The rest is silence. RNA 7: 1509-1521; Hutvagner G et al., RNAi: Nature abhors a double-strand. Curr. Opin. Genetics & Development 12: 225-232; Brummelkamp, 2002, A system for stable expression of short interfering RNAs in mammalian cells. Science 296: 550-553; Lee N S, Dohjima T, Bauer G, Li H, Li M-J, Ehsani A, Salvaterra P, and Rossi J. (2002). Expression of small interfering RNAs targeted against HIV-1 rev transcripts in human cells. Nature Biotechnol. 20:500-505; Miyagishi M, and Taira K. (2002). U6-promoter-driven siRNAs with four uridine 3′ overhangs efficiently suppress targeted gene expression in mammalian cells. Nature Biotechnol. 20:497-500; Paddison P J, Caudy A A, Bernstein E, Hannon G J, and Conklin D S. (2002). Short hairpin RNAs (shRNAs) induce sequence-specific silencing in mammalian cells. Genes & Dev. 16:948-958; Paul C P, Good P D, Winer I, and Engelke D R. (2002). Effective expression of small interfering RNA in human cells. Nature Biotechnol. 20:505-508; Sui G, Soohoo C, Affar E-B, Gay F, Shi Y, Forrester W C, and Shi Y. (2002). A DNA vector-based RNAi technology to suppress gene expression in mammalian cells. Proc. Natl. Acad. Sci. USA 99(6):5515-5520; Yu J-Y, DeRuiter SL, and Turner DL. (2002). RNA interference by expression of short-interfering RNAs and hairpin RNAs in mammalian cells. Proc. Natl. Acad. Sci. USA 99(9):6047-6052.
[0044] Antisense or RNA interference molecules can be delivered in vitro to cells or in vivo, e.g., to tumors of a mammal. Typical delivery means known in the art can be used. For example, delivery to a diseased kidney can be accomplished by direct intrarenal injections. Other modes of delivery can be used without limitation, including: intravenous, intramuscular, intraperitoneal, intraarterial, local delivery during surgery, endoscopic, subcutaneous, and per os. Vectors can be selected for desirable properties for any particular application. Vectors can be viral or plasmid. Adenoviral vectors are useful in this regard. Tissue-specific, cell-type specific, or otherwise regulatable promoters can be used to control the transcription of the inhibitory polynucleotide molecules. Non-viral carriers such as liposomes or nanospheres can also be used.
[0045] Because the channel activity of the disease-associated variant appears to cause increased calcium channel activity, inhibitors of such channel activity can be used therapeutically. Any inhibitor known in the art can be used, including but not limited to 2-aminoethoxy diphenyl borate, gadolinium, and SKF96365. Such inhibitors may have a therapeutic benefit in glomerulonephritis, whether or not the patient carries the P112Q variant. Thus a patient with any glomerulonephritis may be treated with inhibitor. Such patients include those with Focal Segmental Glomerulosclerosis (FSG), Goodpasture's syndrome, an IgA nephropathy, IgM mesangial proliferative glomerulonephritis, Lupus nephritis, Membranoproliferative glomerulonephritis I, Membranoproliferative glomerulonephritis II, Membranoproliferative glomerulonephritis III, post-streptococcal glomerulonephritis, rapidly progressive (crescentic) glomerulonephritis, membranous nephropathy, and diabetic nephropathy.
[0046] Additional calcium channel activity inhibitors can be screened using assays described in the examples below. Cells transfected with a coding sequence for the P112Q variant or cells transfected with a coding sequence for the wild-type TRPC6 can be used as test cells. Ion currents or intracellular calcium accumulation can be measured. The effects of various test substances on the ion currents or intracellular calcium accumulation can be determined and inhibitors thereby identified Inhibitors are candidate therapeutic agents for treating glomerulonephritis.
[0047] Because FSGS associated with the TRPC6 mutation first manifests itself in adults, the identification of a mutation in TRPC6 can be used to predict which children or young adults are likely to manifest the disease. This is especially true among family members of affected individuals. Similarly, identifying family members who do not carry a mutation can also be useful so that anxiety and monitoring and preventive steps can be diminished. Any altered sequence in the TRPC6 gene or protein relative to normal unaffected controls will suggest an increased risk. Further functional tests of the mutant protein may be used to confirm a phenotype of any new mutations identified. Disease causing mutations will cause channel activity similar to that of the P112Q mutation, i.e., increased calcium ion influx into cells. A mutation can be detected either at the nucleic acid or at the protein level. As indicated above, synonymous mutations are unlikely to cause any changed phenotype associated with disease.
[0048] Primer pairs are provided in a single divided or undivided container. Each primer may be packaged separately or in pairs. Similarly, each pair may be packaged separately or in sets. Primers are useful for amplifying regions of TRPC6, especially exon 2, so that mutations can be identified in test samples. Preferably the primers include a pair which amplifies a segment containing codon 112 of TRPC6. Primers can be allele specific, e.g., they will amplify only in the presence of a specific allele, or they may amplify more than one allelic form. An allele-specific primer might hybridize, e.g., to a nucleotide at position 335, either a Cytosine or an Adenine. Probes similarly can be allele specific or not. Probes typically contain a readily detectable moiety, such as a fluorescent, bioluminescent, enzymatic, or radioactive moiety. Probes and primers are typically at least 12, 14, 16, 18, 20, 22, or 25 nucleotides in length.
[0049] As indicated above, antibodies can be used to detect TRPC6 proteins in general, or particular variants. Antibodies can be selected to preferentially bind to particular variants relative to wild-type. The amount of the binding preference may be at least two-fold, at least five-fold, at least ten-fold, or at least twenty-fold. One antibody which is particularly useful is one which preferentially binds to the P112Q variant relative to the wild-type. An antibody with the converse specificity may also be diagnostically useful. Antibodies according to the invention can be polyclonal or monoclonal. Methods of making both types of antibodies are well known in the art. Typically generating antibodies of either type begins with immunization of a sheep, rabbit, mouse, goat, etc., with a specific immunogen which is enriched for the antigen or epitope to which antibodies are desired. Adjuvants may also be used to enhance the immune response to the immunogen. Antibodies can be labeled with a moiety which facilitates detection. Such moieties include enzymatic, radioactive, fluorescent, and luminescent moieties.
[0050] Determining the presence of a mutant form of TRPC6 may be useful, as described above, to identify affected individuals prior to the manifestation of symptoms. In addition, identification of mutation carriers may be useful in assigning patients to treatment regimes. For example, a patient with an P112Q variant is an excellent candidate for receiving TRPC6 inhibitor therapy. In addition, identification of a TRPC6 mutation can be used during clinical trials to stratify patients for drug testing.
[0051] Mutations in several other proteins have been identified in familial nephrotic syndrome and hereditary FSGS. Nephrin (NPHS1), the cause of Finnish nephropathy, is a protein of unknown function that localizes to the glomerular slit diaphragm and appears to form a “zipper-like structure” (20). Podocin (NPHS2) appears to anchor elements of the slit diaphragm to the cytoskeleton (21). Lastly, mutations in alpha-actinin 4 (ACTN4) may alter functions of the actin cytoskeleton in the podocyte (6, 22). CD2-associated protein (CD2AP) has been implicated in glomerular function on the basis of mouse studies (23). CD2AP also appears to have important interactions with nephrin and podocin at the slit diaphragm.
[0052] TRP channels have become the object of intense interest as their role in diverse biological functions emerge. They have been associated with cell growth, ion homeostasis, mechanosensation and PLC-dependent calcium entry into cells. Interestingly, calcium as a second messenger affects many of these same cellular functions. Although the applicants do not wish to be bound by any particular theory or mechanism of operation, the exaggerated calcium signaling conferred by the TRPC6 P112Q mutation may disrupt glomerular cell function or may cause apoptosis (24). Moreover, the mutant TRPC6 P112Q protein may amplify injurious signals triggered by ligands such as angiotensin II that promote kidney injury and proteinuria.
[0053] Clinical manifestations of renal disease do not appear until the 3 rd decade in individuals with the TRPC6 P112Q mutation. This contrasts with Finnish nephropathy and steroid-resistant nephrotic syndrome, whose sufferers typically develop proteinuria in utero or at birth (5). The delay of onset in those carrying the TRPC6 P112Q mutation may reflect the difference between these recessive disorders and the autosomal dominant mechanism of inheritance in our New Zealand family; the presence of one normal TRPC6 allele may postpone the onset of kidney injury. Patients with autosomal dominant FSGS due to mutations in the ACTN4 gene also have a delayed onset of kidney disease.
[0054] The above disclosure generally describes the present invention. All references disclosed herein are expressly incorporated by reference. A more complete understanding can be obtained by reference to the following specific examples which are provided herein for purposes of illustration only, and are not intended to limit the scope of the invention.
Example 1
Identification of Altered Gene in Affected Kindred
[0055] Haplotype analyses reduced the minimal candidate region to an approximate 2.1 centiMorgan (cM) area defined by critical recombination events at D11S1390 and D11S1762 ( FIG. 1A ). This region contains several known genes as well as multiple novel and predicted genes which were systematically screened for mutations by direct sequencing. After examination of 42 other candidate genes, TRPC6 (GenBank Accession No. NP — 004612) emerged as a candidate based on reports of detection of TRPC6 mRNA in the kidney (9, 10). We therefore sequenced each of the 13 exons of the TRPC6 gene along with their intron/exon boundaries. Primer sequences are provided ( FIG. 9 ). As shown in FIG. 1B , we discovered a missense mutation (C335A) in exon 2, from affected individuals, causing a proline to glutamine substitution at position 112 within the first ankyrin repeat of the TRPC6 protein. This variant was present in all of the affected individuals (20 affected; 1 probably affected) in our kindred and there were no non-penetrant carriers. The change was not found in any of the public single nucleotide polymorphism (SNP) databases. Furthermore, we found no evidence of the substitution in 614 chromosomes screened from a group of Caucasian controls without known renal disease, 33 of whom were from New Zealand. The allele frequencies from all markers used for linkage in this kindred and the New Zealand controls are similar to those in the other Caucasian controls. Proline 112 is highly conserved in evolution and is present in TRPC protein homologues from multiple species ( FIG. 5 ).
Example 2
Immunohistological Determination of Protein Expression and FISH Determination of mRNA Expression
[0056] Our previous finding that familial FSGS does not recur in affected patients after renal transplantation indicates a critical role for the kidney in disease pathogenesis (11). While expression of TRPC6 mRNA has been reported in multiple tissues including the kidney, its distribution in kidney is not clear (9, 10). Therefore, to define the spatial distribution of TRPC6 protein expression in human kidney, we performed immunohistochemistry of normal human renal cortex with rabbit antibody raised against a specific human TRPC6 peptide ( FIGS. 2A and 2B ). Immunofluorescence staining revealed TRPC6 expression throughout the kidney in glomeruli and tubules. This is consistent with a recent study detecting TRPC6 mRNA in isolated glomeruli (12). Expression of TRPC6 in glomeruli is particularly noteworthy as abnormal podocyte function appears to be a final common pathway in a variety of proteinuric kidney diseases (13). To verify these immunofluorescence findings, we carried out fluorescent in situ hybridization (FISH) in human kidney sections ( FIG. 2C-2F ). These studies confirmed diffuse expression of TRPC6 mRNA in glomeruli and tubules in a pattern that is virtually identical to that seen with anti-TRPC6 antibody staining
Example 3
Mutation Activates Channel Activity
[0057] To determine the effect of the P112Q mutation on TRPC6 function, we studied HEK 293 cells (human kidney cells) transfected with mutant (TRPC6 P112Q ) or wild-type (WT) TRPC6 (14). The WT TRPC6 was cloned from a human kidney cDNA library. On Western blots, the abundance and mobility of the P112Q mutant was comparable to that of WT TRPC6 ( FIG. 6 ). Diacylglycerol (DAG) is a potent activator of TRPC6 (15). We therefore measured the intracellular calcium concentration ([Ca +2 ]i) using Fura fluorescence in HEK 293 cells expressing either the WT or TRPC6 P112Q after exposure to the DAG analogue OAG (1-oleoyl-2-acetyl-sn-glycerol). OAG perfusion increased late Ca +2 transients in cells transfected with WT TRPC6 as expected ( FIG. 3A and FIG. 7 ). Peak intracellular concentrations were significantly higher in cells expressing the TRpc6 P112Q compared with WT controls ([Ca 2+ ]i TRPC6 P112Q =181±25 nM vs. [Ca 2+ ]i WT TRPC6=106±15 nM; p<0.05).
Example 4
Mutation Enhances Receptor-Operated Calcium Signaling
[0058] Angiotensin II acting through its AT1 receptor plays a critical role in the generation of proteinuria and progression of kidney injury in a number of kidney diseases including FSGS (16). AT1 receptors, coupled to heterotrimeric G nucleotide-binding proteins, activate phospholipase C-beta isoforms that hydrolyze phosphatidylinositol 4,5-bisphosphate (PIP 2 ). This triggers production of inositol 1,4,5-trisphosphate (InsP 3 ) and diacylglycerol (DAG) releases internal calcium stores and activates Ca +2 entry, respectively (17). We examined whether the P112Q mutation would affect angiotensin II-dependent (i.e., receptor-operated) calcium signaling. HEK 293 cells were co-transfected with the AT1 angiotensin receptor (AT-YFP) and either WT TRPC6 or TRPC6 P112Q . [Ca +2 ] i changes were measured after exposure to angiotensin II ( FIG. 3B and FIG. 8 ); similar to the OAG experiments, the peak angiotensin II-stimulated [Ca +2 ] i was higher in cells expressing the mutant protein compared with WT controls ([Ca 2+ ]i TRPC6 P112Q =640±66 nM vs. [Ca 2+ ]i WT TRPC 6=357±46 nM; p<0.05). To establish that the P112Q mutation is not isolated to TRPC6 channels, we introduced the analogous mutation into the TRPC3 channel. Our results demonstrate the same augmented Ca 2+ entry observed with the TRPC6 P112Q mutation.
Example 5
Mutation Increases Surface Expression of TRPC6
[0059] We also evaluated the subcellular localization of the mutant TRPC6 protein by performing surface biotinylation experiments ( FIG. 3D ). These confirmed that the relative distribution of TRPC6 P112Q protein in the plasma membrane was significantly greater than the wild-type protein (densitometry—WT TRPC6=1210.33 vs. TRPC6 P112Q =23126.67 units; p=0.05). Because the transferrin receptor (TfR) is constitutively expressed on the cell surface, we probed the cell surface fraction with an antibody to TfR as a control. No difference was found in the surface expression of TfR in cells transfected with either WT TRPC6 or TRPC6 P112Q . Likewise, we probed the cell surface fraction with antibody to the cytosolic protein actin and found no non-specific labeling of intracellular proteins. Our findings are in accordance with reports by others (18, 19). This enhanced cell surface expression of TRPC6 P112Q protein suggests a mechanism of exaggerated calcium signaling and flux.
Example 6
Materials and Methods
Ascertainment and Diagnostic Criteria
[0060] The ascertainment and clinical diagnosis are as previously described (1). Family 6530 was initially identified by the Department of Nephrology, Christchurch Hospital, Christchurch, New Zealand. All available renal biopsies and biopsy reports were independently reviewed by D.N.H. Evaluation of the family included a complete family history and an assay of serum creatinine and urinalysis where appropriate. Asymptomatic individuals were examined for proteinuria with qualitative urinalysis. The Duke University Medical Center (Durham, N.C.) Institutional Review Board and the Canterbury Ethics Committee approved this project and all participants gave signed informed consent prior to data and DNA collection.
Haplotype Analysis
[0061] Haplotype analysis was performed as previously described to identify critical recombination events (2). The haplotypes were constructed via visual inspection and by SIMWALK2 computerized haplotyping algorithm. Genetic and physical map distances as well as marker order were obtained from public databases (websites at genome.cse.ucsc.edu and research.marshfieldclinic.org/genetics/).
DNA Isolation and Genotyping
[0062] Genomic DNA was isolated from peripheral blood through the Center for Human Genetics, Duke University Medical Center using PureGene™ (Gentra). Genotyping was carried out as described by Vance et al., (3). Microsatellite markers within the area of interest were identified from a variety of sources, including, ensembl.org, and genome.cse.ucsc.edu. A Hitachi FMBIOII was used for detection, data was processed using Biolmage® and databased using Pedigene® (4).
TRPC6 Sequencing and Mutation Detection
[0063] TRPC6 exons were amplified using the polymerase chain reaction (PCR) with primers that were designed using the Primer 3 design software (website at genome.wi.mit.edu/cgi-bin/primer/primer3_www.cgi) from known genomic sequence (website at genome.cse.ucsc.edu) using standard PCR protocols. Both strands of DNA were sequenced. Targeted sequence included all exons and 25-50 base pairs of the intronic sequence surrounding each exon. PCR products were purified using the QIAquick PCR purification kit (Qiagen). Sequencing reactions were performed using BigDye® Terminator V3.1 Cycle Sequencing Kit (Applied Biosystems) and purified using Edge Biosystems Gel Filtration Columns (Edge Biosystems). Sequencing was carried out using the ABI 3730 DNA Analyzer (Applied Biosystems) and analyzed using Sequencher DNA sequencing analysis software (Gene Codes Corporation).
Immunofluorescent Staining
[0064] Normal human renal tissue was embedded in gelatin, snap frozen in liquid-nitrogen-cooled 2-methylbutane, and stored at −85° C. Frozen sections were cut at 4 μm, air dried, and fixed in acetone. For immunofluorescent staining, sections were incubated for 30-min at 25° C. with rabbit anti-TRPC6 (Chemicon) at a dilution of 1:50 and a mouse anti-synaptopodin monoclonal antibody (Progen Biotechnik GmBH) at 1:64 in phosphate-buffered saline, pH 7.4 (PBS) supplemented with 1% bovine serum albumin (PBS/BSA). The TRPC6 antibody was raised against a 16-amino-acid peptide that is identical to the human TRPC6 sequence in 15 of 16 residues (Mouse Peptide—RRNESQDYLLMDELG; SEQ ID NO: 68). The immunizing peptide does not align with any amino acid sequence other than TRPC6 according to a protein BLAST search (website at ncbi.nlm.nih.gov) of the human genome and according to printed material from the companies supplying the antibody. Additionally, we have found that this antibody does not recognize recombinant TRPC3, one of the members of the TRPC3/6/7 subfamily, on Western blot. The synaptopodin antibody has been well-characterized (5). Following two washes with PBS, biotinylated goat-anti-rabbit IgG (Jackson ImmunoResearch Laboratories, Inc.) at a dilution of 1:400 and Cy3-conjugated donkey-anti-mouse IgG at 1:400 in PBS/BSA were added. After an additional 30-min incubation and two washes with PBS, Cy2-conjugated streptavidin (Jackson ImmunoResearch Laboratories) at a dilution of 1:400 was added. Following a final 30-min incubation and two additional washes with PBS, the sections were mounted with 80% glycerol in 0.25M Tris buffer, pH 7.7, and examined using an epifluorescence microscope equipped with green excitation/red emission and blue excitation/green emission filter sets. As negative controls, additional sections were stained in parallel with either pre-immune immunoglobulin of the relevant species or anti-TRPC6 preincubated with a molar excess of the immunizing peptide substituted for the primary antibody. Sections were also incubated with rabbit anti-TRPC6 at a dilution of 1:50 and mouse anti-CD34 (BD Biosciences) at a dilution of 1:400 with staining carried out in the same manner as above.
Fluorescent In Situ Hybridization for TRPC6
[0065] Normal human renal tissue was fixed for 16 hours in paraformaldehyde, paraffin embedded, and sections cut at 4-5 microns in thickness. For in situ hybridization, sections were incubated with DIG-labeled probes corresponding to the sense and anti-sense strands of the of TRPC6 cloned from human kidney (Clontech). The probe was generated by digestion of the human kidney cDNA library with EcoRV and BamH1 (corresponding nucleotide 2301-5′ TATCACTTGG . . . (SEQ ID NO: 66); corresponding nucleotide 3621- . . . TTATTTCAGG 3′(SEQ ID NO: 67); accession number AJ006276). The resulting fragment was cloned into pBS. For DIG labeling, probes were generated by in vitro transcription according to the manufacturer's protocol (Roche). Serial washes in SSC were followed by a blocking step with 5% normal rabbit IgG (Dako) RT30-40 min and then with (1:200) HRP-rabbit anti-DIG Ab RT45-60 min (Roche). Sections were washed with TBST and then incubated with Cy3 conjugated tyramide for 5 minutes and then coverslipped. Sections were examined using confocal microscopy with a filter set optimized for Cy3. Background staining in the sense hybridization sections reflect autofluorescence from red blood cells trapped at the time of kidney harvest.
Cloning of TRPC6 and Mutagenesis of TRPC6 C335A
[0066] The open reading frame of human TRPC6 was cloned by PCR from a human kidney cDNA library (Clontech). PCR primers were designed to amplify several fragments and the overlapping clones were sub-cloned into the mammalian expression vector pcDNA3.1 (Invitrogen) with a CMV promoter. Site-directed mutagenesis was carried out using Quickchange kit (Stratagene) to construct the C335A mutation. The resulting mutant clone was sequenced to confirm the base change as well the entire full-length sequence. Where indicated the ORF for TRPC6 and TRPC6 P112Q were cloned into the pEF-V5 expression plasmid (Invitrogen) and pCMV-N1GFP expression plasmid (Clontech) as previously with TRPC3 (6).
[0067] Cell transfection, Surface Expression and Imaging of TRPC6
[0068] HEK 293 cells were plated on glass bottom plates at near confluence. After 24 hours, the cells were transfected with plasmids in the presence of lipofectamine 2000 (Invitrogen). Here 3 μg of TRPC6 plasmid (WT or mutant) and 1 μg of ATR-YFP plasmid were incubated for 4 hours in Optimem 2000 media (Gibco) and then changed to 10% FBS/DMEM media. For biotinylation experiments, 24 hours after transfection with TRPC6-V5 and TRPC6 P112Q -V5 constructs, cells were washed with ice cold PBS and incubated with sulfo-NHS-SS-Biotin (2 mg/ml) (Pierce) for 30-min at 4° C. After 3 washes with PBS with 10 mM glycine, cells were incubated with RIPA lysis buffer for 30-min at 4° C. Lysates were passed through a 20G and then 25G needle for 25 passes. Samples were then collected by centrifuging at 20K G for 15-min at 4° C. Supernatants were then incubated overnight with streptavidin agaraose beads (Pierce), washed 3 times and then heated to 37° C. Samples were then subjected to SDS-PAGE and immunoblotting with an antibody raised against the V5 epitope tag (Invitrogen). Samples were then immunoblotted with a monoclonal anti-transferrin receptor antibody as a control (Sigma-Aldrich). For determining total cellular TRPC6 expression, protein extracts were collected prior to streptavidin bead incubation. For immunostaining experiments, cells were fixed with ice-cold methanol, permeabilized, and incubated with the TRPC6 antibody and followed by a FITC-conjugated secondary antibody. Standard epifluorescence microscopy was used to collect a series of Z images which were then stacked and processed using Metafluor image processing (Universal Imaging).
Single Cell Imaging of Divalent Cations
[0069] HEK 293 cells transfected with plasmids (TRPC6, TRPC6 P112Q and ATR-YFP) were attached to glass coverslips and loaded with 1-10 μM Fura-2 AM (Molecular Probes) for 45-min. Following a de-esterification period of 30-min, cells were imaged by an epifluorescent microscopy system designed to capture rapid calcium transients as previously described (6). Cells were then stimulated with angiotensin II (1 μM) or 100 μM 1-oleoyl-2-acetyl sn-glycerol (OAG) (Calbiochem) in a barium containing solution. The lambda DG4 (Sutter Instruments) provides for rapid excitation filter changes and 340/380 ratios are captured every 10-100 msec from a Cool SNAP HQ CCD camera (Roper Scientific). All components including the filter selection, stage temperature, shutters and motorized stage are controlled by Metafluor software (Universal Imaging).
Whole Cell Current Recordings and Patch Clamp
[0070] HEK 293 were plated on glass coverslips and transfected with TRPC6-GFP and TRPC6 P112Q -GFP. Bath solution comprised of (in mM): 140 NaCl, 2 BaCl 2 , 2.8 KCl, 1.0 MgCl 2 , 10 HEPES, 10 dextrose, adjusted to pH 7.4 with NaOH. For Na + free solution, NaCl was replaced with 140 mM NMDG. The patch pipette solution was comprised of (in mM): 140 Cs aspartate, 5 NaCl, 10 HEPES, 10 BAPTA and 1 Mg 2 ATP (pH 7.3, KOH). Electrodes were pulled from type 7052 glass (Garner Glass Co.) and had resistances of 2-5 Mohms. The cells were voltage clamped using the whole-cell patch clamp technique (7). The electrodes were fire-polished and coated with Sylgard 184. Offset potentials between the solution and the bath were zeroed prior to seal formation. Currents were measured with a Dagon 3900 amplifier. Data acquisition and voltage pulses were controlled with pClamp 8.0 software and the Digidata 1300 system from Axon Instruments. All patch clamp recordings were at room temperature.
REFERENCES AND NOTES
[0071] The disclosure of each reference cited is expressly incorporated herein.
1. T. Srivastava, S. D. Simon, U. S. Alon, Pediatric Nephrology 13, 13 (1999). 2. A. Hurtado et al., Clin. Nephrol. 53, 325 (2000). 3. S. M. Korbet, R. M. Genchi, R. Z. Borok, M. M. Schwartz, American Journal of Kidney Diseases 27, 647 (1996). 4. M. Kestila et al., Molecular Cell 1, 575 (1998). 5. N. Boute et al., Nat. Genet. 24, 349 (2000). 6. J. M. Kaplan et al., Nat. Genet. 24, 251 (2000). 7. M. P. Winn et al., Kidney Int. 55, 1241 (1999). 8. M. P. Winn et al., Genomics 58, 113 (1999). 9. A. Riccio et al., Brain Res. Mol. Brain. Res. 109, 95 (2002). 10. R. L. Garcia, W. P. Schilling, Biochem. Biophys. Res. Commun. 239, 279 (1997). 11. P. J. Conlon et al., Kidney Int. 56, 1863 (1999). 12. C. S. Facemire, P. J. Mohler, W. J. Arendshorst, Am. J. Physiol Renal Physiol 286, F546 (2004). 13. P. Mundel, S. J. Shankland, J. Am. Soc. Nephrol. 13, 3005 (2002). 14. The HEK293 cell line was originally derived from human embryonic kidney and its morphological features bear little or no resemblance to mature renal cell lineages. Thus, the absence of TRPC6 expression in HEK cells probably has little bearing on whether or not the protein is actually expressed in mature kidney tissue. An example of this phenomenon are the angiotensin receptors which are not expressed in HEK cells but are expressed throughout the kidney. 15. T. Hofmann et al., Nature 397, 259 (1999). 16. M. W. Taal, B. M. Brenner, Kidney Int. 57, 1803 (2000). 17. T. Balla, P. Varnai, Y. Tian, R. D. Smith, Endocr. Res. 24, 335 (1998). 18. B. B. Singh et al., Mol. Cell. 15, 635 (2004). 19. V. J. Bezzerides, I. S. Ramsey, S. Kotecha, A. Greka, D. E. Clapham, Nat. Cell Biol. 6, 709 (2004). 20. V. Ruotsalainen et al., Proc. Natl. Acad. Sci. U.S. A 96, 7962 (1999). 21. S. Roselli et al., Am. J. Pathol. 160, 131 (2002). 22. C. H. Kos et al., J. Clin. Invest 111, 1683 (2003). 23. K. Schwarz et al., J. Clin. Invest 108, 1621 (2001). 24. Y. Hara et al., Mol. Cell. 9, 163 (2002).
Supporting Reference List for example 6
[0000]
1. M. P. Winn et al., Genomics 58, 113 (1999).
2. M. A. Pericak-Vance, in Current Protocols in Human Genetics , N. C. Dracopoli et al., Eds. (John Wiley And Sons, Inc., New York, 1997), p. 1.
3. J. M. Vance, K. Ben Othmane, in Approaches to Gene Mapping in Complex Human Diseases , J. L. Haines, M. A. Pericak-Vance, Eds. (Wiley-Liss, New York, 1998), pp. 213-228.
4. C. Haynes et al., paper presented at Am J Human Genet. 1995.
5. L. Barisoni et al., Kidney Int. 58, 137 (2000).
6. P. Rosenberg et al., Proc. Natl. Acad. Sci. U.S. A 101, 9387 (2004).
7. T. L. Creazzo, J. Burch, R. E. Godt, Biophys. J. 86, 966 (2004).
8. A. Dietrich et al., J. Biol. Chem. 278, 47842 (2003).
9. G. Vazquez, B. J. Wedel, M. Trebak, B. G. St John, J. W. Putney, Jr., J. Biol. Chem. 278, 21649 (2003).
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Focal and segmental glomerulosclerosis (FSGS) is a kidney disorder of unknown etiology and up to 20% of patients on dialysis have this diagnosis. A large family with hereditary FSGS carries a missense mutation in the TRPC6 gene on chromosome 11q, encoding the ion channel protein Transient Receptor Potential Cation Channel 6. The missense mutation is a P112Q substitution, which occurs in a highly conserved region of the protein, enhances TRPC6-mediated calcium signals in response to agonists such as angiotensin II, and alters the intracellular distribution of TRPC6 protein. Previous work has emphasized the importance of cytoskeletal and structural proteins in proteinuric kidney diseases. Our findings suggest a novel mechanism for glomerular disease pathogenesis.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2016-0023096, filed on Feb. 26, 2016, the entire contents of which are incorporated herein by reference.
FIELD
[0002] The present disclosure relates to a method and system for controlling a coolant circulating in an engine that may accurately control a coolant temperature.
BACKGROUND
[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0004] Generally, a mechanical thermostat is used to control a temperature of a coolant circulating in an engine, and the mechanical thermostat has a structure in which wax of the mechanical thermostat expands to open a coolant flow path connected to a radiator and to control the temperature of the coolant when the temperature of the coolant increases.
[0005] The mechanical thermostat is disposed at a coolant outlet of an engine to control an outlet temperature of the engine or at a coolant inlet of the engine to control an inlet temperature of the engine, wherein the former is referred to as an engine outlet control method and the latter is referred to as an engine inlet control method.
[0006] Since the engine outlet control method senses a temperature of a coolant flowing out of the engine and then performs predetermined control, it is possible to prevent the temperature of the coolant from being excessively increased, but since a point for sensing the temperature of the coolant is positioned at the coolant outlet of the engine, accuracy of the control may be degraded.
[0007] In contrast, since the engine inlet control method senses the temperature of the coolant at an inlet of the engine, variation of the temperature of the coolant is small and accuracy of the control is high, but the temperature of the outlet of the engine may excessively increase according to output of the engine.
[0008] The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.
[0009] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
SUMMARY
[0010] The present disclosure provides a method and system for controlling a coolant circulating in an engine that may implement advantages of an engine inlet control method and an engine outlet control method and may rapidly and accurately control a temperature of the coolant.
[0011] Particularly, the present disclosure provides a method and system for controlling a coolant circulating in an engine that may rapidly and accurately control a temperature of the coolant by correcting an inlet temperature reference value of the coolant according to a difference value between a coolant temperature of an engine outlet and a coolant temperature of an engine inlet.
[0012] Further, the present disclosure provides a method and system for controlling a coolant circulating in an engine that includes a coolant control valve unit that is electronically controlled and that may control a temperature of a coolant supplied to an inlet of the engine by respectively controlling a coolant supplied to a radiator and a coolant bypassing the radiator.
[0013] One form of the present disclosure provides a method for controlling a coolant circulating in an engine, including: selecting a reference inlet temperature for a coolant flowing through a coolant inlet of an engine; controlling an open rate of the coolant control valve unit based on the reference inlet temperature; sensing an actual inlet temperature of the coolant flowing through the coolant inlet of the engine; sensing an actual outlet temperature of a coolant flowing through a coolant outlet of the engine; calculating a difference value between the actual inlet temperature and the actual outlet temperature; and varying the reference inlet temperature according to the difference value.
[0014] The reference inlet temperature may be selected based on the actual outlet temperature of the coolant flowing through the coolant outlet of the engine.
[0015] The coolant control valve unit may supply a coolant discharged from the coolant outlet of the engine to the radiator or to the coolant inlet of the engine by bypassing the radiator, and it may respectively control the coolant supplied to the radiator and the coolant inlet of the engine according to the open rate of the coolant control valve unit.
[0016] As the difference value between the actual inlet temperature and the actual outlet temperature increases, a correction value of the reference inlet temperature may increase.
[0017] When the reference inlet temperature is lowered, the coolant control valve unit may increase an amount of the coolant supplied to the radiator.
[0018] As the difference value between the actual inlet temperature and the actual outlet temperature increases, the reference inlet temperature may be lowered.
[0019] The actual inlet temperature and the actual outlet temperature may be respectively sensed by first and second coolant temperature sensors.
[0020] The coolant may be pumped to the coolant inlet of the engine by a coolant pump.
[0021] Another form of the present disclosure provides a system for controlling a coolant circulating in an engine, including: an engine configured to generate torque through a combustion process, for a coolant to be supplied to a coolant inlet thereof, and for the coolant to be discharged from a coolant outlet thereof; first and second coolant temperature sensors that are respectively installed at the coolant inlet and the coolant outlet to sense a temperature of the coolant; a radiator that is installed at one side of the engine to discharge heat of the coolant to the outside; a coolant control valve unit that is installed at the coolant outlet to distribute a coolant discharged from the engine to the radiator or to the coolant inlet by bypassing the radiator; and a controller that senses the temperature of the coolant through the first and second coolant temperature sensors, controls the coolant control valve unit, selects a reference inlet temperature for a coolant flowing through the coolant inlet, controls an open rate of the coolant control valve unit based on the reference inlet temperature, senses an actual inlet temperature of the coolant flowing through the coolant inlet, senses an actual outlet temperature of the coolant flowing through the coolant outlet, calculates a difference value between the actual inlet temperature and the actual outlet temperature, and varies the reference inlet temperature according to the difference value.
[0022] The reference inlet temperature may be selected based on the actual outlet temperature of the coolant flowing through the coolant outlet of the engine.
[0023] As the difference value between the actual inlet temperature and the actual outlet temperature increases, a correction value of the reference inlet temperature may increase.
[0024] When the reference inlet temperature is lowered, the coolant control valve unit may increase an amount of the coolant supplied to the radiator.
[0025] As the difference value between the actual inlet temperature and the actual outlet temperature increases, the reference inlet temperature may be lowered.
[0026] The system may further include a coolant pump that is disposed at the coolant inlet of the engine to pump the coolant to the coolant outlet.
[0027] According to one form of the present disclosure, it is possible to rapidly and accurately control a temperature of the coolant by correcting an inlet temperature reference value of the coolant according to a difference value between a coolant temperature of an engine outlet and a coolant temperature of an engine inlet.
[0028] According to one form of the present disclosure, it is possible to provide a coolant control valve unit that is electronically controlled and that may control a temperature of a coolant supplied to an inlet of the engine by respectively controlling a coolant supplied to a radiator and a coolant bypassing the radiator.
[0029] That is, it is possible to actively follow and control the temperature of the coolant actually flowing in the engine by controlling a flow rate of the coolant flowing from the radiator for cooling the coolant and the coolant bypassed by the coolant control valve unit, and by controlling the temperature of the coolant supplied to the inlet of the engine.
[0030] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0031] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:
[0032] FIG. 1 illustrates a schematic diagram of a system for controlling a coolant circulating in an engine according to one form of the present disclosure;
[0033] FIG. 2 illustrates a flowchart of a method for controlling a coolant circulating in an engine according to one form of the present disclosure;
[0034] FIG. 3 illustrates a schematic cross-sectional view for explaining an operation principle of a coolant control valve unit for controlling a coolant circulating in an engine according to one form of the present disclosure; and
[0035] FIG. 4 illustrates a graph of a coolant control pattern according to one form of the present disclosure.
[0036] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
DESCRIPTION OF SYMBOLS
[0037]
[0000]
100: engine
110: coolant control valve unit
120: radiator
130: first coolant temperature sensor
140: second coolant temperature sensor
150: coolant pump
160: controller
300: valve housing
305: port
310: rotary valve
DETAILED DESCRIPTION
[0038] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
[0039] Forms of the present disclosure will hereinafter be described in detail with reference to the accompanying drawings.
[0040] FIG. 1 illustrates a schematic diagram of a system for controlling a coolant circulating in an engine according to one form of the present disclosure.
[0041] Referring to FIG. 1 , a system for controlling a coolant circulating in an engine includes an engine 100 , a first coolant temperature sensor 130 , a second coolant temperature sensor 140 , a coolant control valve unit 110 , a radiator 120 , a coolant pump 150 , and a controller 160 .
[0042] The first coolant temperature sensor 130 is disposed at a coolant inlet of the engine 100 to sense a temperature of a coolant flowing into the engine through the coolant inlet, and the second coolant temperature sensor 140 is disposed at a coolant outlet of the engine 100 to sense a temperature of a coolant flowing out of the engine through the coolant outlet.
[0043] The radiator 120 serves to radiate or dissipate heat of a supplied coolant to the outside, and the coolant pump 150 pumps the coolant supplied from the radiator 120 or the coolant control valve unit 110 to circulate the coolant from the coolant inlet to the coolant outlet of the engine 100 .
[0044] The coolant control valve unit 110 is electronically controlled by the controller 160 to respectively control the coolant supplied to the radiator 120 and the coolant bypassing the radiator 120 . Moreover, the coolant control valve unit 110 may control the coolant to not flow when the temperature of the coolant is equal to or less than a predetermined temperature.
[0045] In one form of the present disclosure, the coolant control valve unit 110 is electronically controlled by the controller 160 to continuously and variably control a flow amount of the coolant supplied to the radiator 120 and the coolant bypassing the coolant control valve unit 110 .
[0046] The controller 160 may be implemented by one or more processors operated by a predetermined program, and the predetermined program may include a series of commands for performing a method according to one form of the present disclosure described later.
[0047] First of all, the controller 160 controls the coolant control valve unit 110 , for example, the controller 160 controls a coolant temperature of the coolant inlet of the engine 100 based on a predetermined reference inlet temperature. In other words, the controller 160 controls the coolant control valve unit 110 so that the coolant temperature of the coolant inlet of the engine 100 reaches the reference inlet temperature (e.g., about 90° C.).
[0048] Then, actual inlet and outlet coolant temperatures of the engine 100 are sensed through the first coolant temperature sensor 130 and the second coolant temperature sensor 140 , and a difference value between the actual inlet and outlet coolant temperatures is calculated.
[0049] In addition, the reference inlet temperature is varied according to the difference value, and the coolant control valve unit 110 is controlled based on the varied reference inlet temperature. Accordingly, it is possible to actively control the temperature of the coolant circulating in the engine 100 and to variably control the temperature of the coolant according to a load of the engine 100 .
[0050] FIG. 2 illustrates a flowchart of a method for controlling a coolant circulating in an engine according to one form of the present disclosure.
[0051] Referring to FIG. 2 , driving conditions are sensed at step S 200 . In this case, the driving conditions include Revolutions per Minute (RPM) of the engine, torque of the engine, an external air temperature, etc.
[0052] The controller 160 selects the reference inlet temperature of the coolant from map data at step S 210 . The reference inlet temperature may be one selected from predetermined data, or may be an actual outlet temperature of the coolant sensed by the second coolant temperature sensor 140 .
[0053] The controller 160 controls the coolant control valve unit 110 based on the reference inlet temperature at step S 220 . For example, the controller 160 continuously controls a valve angle of the coolant control valve unit 110 so that the inlet temperature of the coolant follows the reference inlet temperature, and the controller 160 controls a flow amount of the coolant flowing in the radiator 120 and a flow amount of the coolant flowing in the coolant control valve unit 110 , thereby controlling the temperature of the coolant inflowing through the coolant inlet of the engine 100 .
[0054] In this case, a proportional-integral-derivative (PID) control may be performed to control a valve open degree of the coolant control valve unit 110 at step S 225 .
[0055] The controller 160 senses the actual outlet temperature of the coolant through the second coolant temperature sensor 140 at step S 230 . In addition, the controller 160 senses the actual inlet temperature of the coolant through the first coolant temperature sensor 130 , and the controller 160 calculates the difference value between the actual inlet temperature and the actual outlet temperature of the coolant at step S 230 .
[0056] The controller 160 determines whether the difference value is greater than the predetermined value and whether a state in which the difference value is greater than the predetermined value is maintained during a predetermined time at step S 240 .
[0057] If the difference value is not greater than the predetermined value or the state in which the difference value is greater than the predetermined value is not maintained during the predetermined time, the process of step S 220 is performed to normally control the coolant flowing through the radiator and the coolant control valve unit, and if the difference value is greater than the predetermined value and the state in which the difference value is greater than the predetermined value is maintained during the predetermined time, the reference inlet temperature of the coolant is corrected or changed at step S 250 .
[0058] Alternatively, if the difference value between the actual inlet temperature and the actual outlet temperature is greater than the predetermined value and the state in which the difference value is greater than the predetermined value is maintained during the predetermined time, the actual inlet temperature of the coolant flowing through the coolant inlet of the engine may be corrected to be lower.
[0059] In one form of the present disclosure, the controller 160 determines that the difference value between the actual inlet temperature and the actual outlet temperature increases as that the load of the engine 100 increases to be able to further lower the reference inlet temperature.
[0060] When the reference inlet temperature is lowered through the coolant control valve unit 110 , the controller 160 may variably increase an amount of the coolant supplied from the coolant control valve unit 110 to the radiator 120 .
[0061] FIG. 3 illustrates a schematic cross-sectional view for explaining an operation principle of a coolant control valve unit for controlling a coolant circulating in an engine according to one form of the present disclosure.
[0062] Referring to FIG. 3 , the coolant control valve unit 110 includes a valve housing 300 and a rotary valve 310 . The rotary valve 310 is provided with a port 305 for the coolant to flow from the inside to the outside, and the port 305 is disposed in a predetermined position of the rotary valve 310 .
[0063] The port 305 is selectively connected to the radiator 120 or a bypass flow path according to a rotation position of the rotary valve 310 , thus the coolant supplied to a central portion of the rotary valve 310 is distributed to the radiator 120 or the bypass flow path.
[0064] FIG. 4 illustrates a graph of a coolant control pattern according to one form of the present disclosure.
[0065] Referring to FIG. 4 , a horizontal axis thereof indicates the rotation position of the rotary valve 310 , and a vertical axis thereof indicates an open amount of the port 305 .
[0066] Specifically, when the rotation position of the rotary valve 310 is an angle of approximately 60 degrees, the port is opened by approximately 100% at a side of the bypass flow path and is opened by approximately 0% at a side of the radiator 120 .
[0067] When the rotation position of the rotary valve 310 is an angle of approximately 80 degrees, the port is opened by approximately 80% at a side of the bypass flow path and is opened by approximately 20% at a side of the radiator 120 , and an open rate of the port 305 connected to the radiator 120 or to the bypass flow path may be continuously varied according to the rotation position of the rotary valve 310 .
[0068] Accordingly to one form of the present disclosure, by respectively sensing the temperatures of the coolant inlet and the coolant outlet of the engine 100 and then controlling the temperature of the coolant, it is possible to relatively constantly maintain the coolant temperature of the coolant outlet of the engine 100 and to minimize variation of the coolant temperature according to the load of the engine 100 .
[0069] Since the control performance for the coolant temperature varies according to the inlet and outlet positions of the engine using the conventional mechanical thermostat, although there are limitations in designing the engine in the conventional art, the control according to one form of the present disclosure is performed according to the coolant temperatures of the inlet and outlet of the engine 100 regardless of the position of the coolant control valve, thus flexibility for designing the engine is improved.
[0070] Further, according to one form of the present disclosure, controllability for the coolant is stably maintained in a transient state such as sudden acceleration or a sudden stop.
[0071] According to one form of the present disclosure, the first coolant temperature sensor 130 is installed between the coolant pump 150 and the coolant inlet of the engine at a lower side of a portion at which the outlet of the radiator 120 and the outlet of the coolant control valve unit 110 are merged, the second coolant temperature sensor 140 is installed at the coolant outlet of the engine 100 , the open rate of the coolant control valve unit 110 is controlled by the PID control according to the difference between the temperatures of the coolant inlet and outlet of the engine 100 , and the coolant flowing through the radiator 120 and the coolant flowing through the coolant control valve unit 110 are continuously controlled, thereby accurately and rapidly controlling the coolant temperature of the coolant inlet of the engine 100 .
[0072] Further, when the difference value between the coolant temperatures of the coolant inlet and outlet is determined to be greater than the predetermined value, it is possible to actively control the coolant temperature in the transient sate of the engine 100 by increasing or decreasing the coolant temperatures of the coolant inlet.
[0073] While this disclosure has been described in connection with what is presently considered to be practical forms, it is to be understood that the disclosure is not limited to the disclosed forms, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of present disclosure.
[0074] The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.
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The present disclosure provides a method and system, for controlling a coolant circulating in an engine, including: selecting a reference inlet temperature for a coolant flowing through a coolant inlet of an engine; controlling an open rate of the coolant control valve unit based on the reference inlet temperature; sensing an actual inlet temperature of the coolant flowing through the coolant inlet of the engine; sensing an actual outlet temperature of a coolant flowing through a coolant outlet of the engine; calculating a difference value between the actual inlet temperature and the actual outlet temperature; and varying the reference inlet temperature according to the difference value.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of German patent application number 10 2009 034 309.1 filed Jul. 16, 2009, the entire disclosure of which is incorporated by reference herein. This application also claims priority of German patent application number 10 2010 025 114.3 filed Jun. 25, 2010, the entire disclosure of which is incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to a microscope including a microscope body and a stand formed by one or more components to provide a supporting function or to enable positioning of the microscope in the room. These components are hereinafter jointly referred to as a stand. The stand includes one or more support arms, for example, in the form of a parallelogram linkage support.
BACKGROUND ART
[0003] Many different techniques are known for illuminating objects to be observed using a wide variety of different microscopes. Moreover, in particular for surgical stereomicroscopes, various techniques are known whereby additional information, such as, for example, information on the various operating conditions, or operating mode indications of the microscope, can be projected into one or more observation beam paths of such a microscope.
[0004] Thus, conventional microscopes typically have a light source for illuminating the object field to be viewed. The design and operation of the microscope and/or its stand are of minor importance in this connection. Also, to date, the microscope has not been used as a light source for the room in which it is located, and information on the microscope could only been read from a display or from discrete control elements, indicators, or the like.
[0005] Document DE102005036230B3 describes a microscope having light-emitting diodes mounted in the body or stand thereof to illuminate the object field.
[0006] Accordingly, the light-emitting diodes are used for purposes of object field illumination.
[0007] Document DE102007051909A1 discloses a microscope having a light source provided in the body thereof, said light source illuminating the object field via a deflection mirror. Thus, this light source is also used for purposes of object field illumination and does not have any other function.
[0008] Document U.S. Pat. No. 2,766,655A1 describes a phase contrast microscope whose object field illumination means is arranged within the stand, from where illumination light is directed into the microscope body, and from there via a mirror onto the object field. Here, too, the illumination system is used exclusively for purposes of object field illumination.
SUMMARY OF THE INVENTION
[0009] It is, therefore, an object of the present invention to provide a microscope having an improved device, using the existing housings of the microscope and/or its stand.
[0010] More specifically, it is an object of the present invention to use the microscope and/or its stand more universally and, by implementing at least one additional light source besides a light source that may be provided for object field illumination, to enable the microscope and/or its stand to be used also for room illumination purposes or to illuminate the microscope or its stand (apart from the area to be viewed through the microscope) and, optionally, to make light available for further information purposes.
[0011] The present invention includes at least one light source which is disposed within the microscope body and/or the stand and which emits its light outwardly into the room through passage openings when in the operating condition, independently of the microscope illumination, and which is not used for purposes of object field illumination.
[0012] The light source and the passage openings may be designed to merely improve the perception of the microscope or the stand in space (for example, in twilight conditions).
[0013] More specifically, the light source and the passage openings may be designed to simulate different appearances of the microscope or stand using different light intensities or colors.
[0014] Yet more specifically, the light source and the passage openings may be designed to provide illumination effects which vary over time so as to distract the patient, and thus to increase the safety of the treatment.
[0015] Variation of the light color can best be accomplished by inserting color filters, or by using colored light-emitting diodes which are driven as needed and according to the desired color mixture.
[0016] The light source and the passage openings may also be designed to provide indirect room illumination.
[0017] In addition, the light source and the passage openings may be designed to deliver signals to a user and/or to change the visible exterior appearance of the microscope or stand using different light colors.
[0018] This illumination system for indirect external illumination may also include a plurality of light sources and a plurality of passage openings for the passage of this light into the room external to the microscope or stand.
[0019] To date, no techniques or devices are known which, except for external indicator lamps, such as externally mounted LEDs, would allow the appearance of the microscope or stand to be changed, or different operating conditions or operating mode indications to be displayed, on the exterior of the microscope body or stand and/or which would provide means for providing indirect room illumination.
[0020] However, it appears desirable to provide such additional display options so as to allow selected operating conditions of a microscope, or changes thereto, to be made visible not only to the operator, but also to other people, especially for example a patient, who are present in the room in which the microscope is located, and to do so independently of the image acquired by the microscope; i.e., the image of an object being viewed.
[0021] The present invention achieves the object described above, making it possible to implement both indirect room illumination and a means for distracting patients, and allowing operating conditions or operating mode indications, and also the extent of the microscope or its stand, to be displayed or made visible externally in a simple manner. In accordance with the present invention, at least one cavity of the microscope and/or the stand has/have a light source disposed therein whose light can pass outwardly into the room through one or more passage openings.
[0022] It is preferred for the light source to be variable, particularly preferably to be variable over time.
[0023] The passage openings are preferably disposed and configured such that the emerging light indirectly illuminates the exterior of the microscope or its stand, or the room in which it is located.
[0024] It is also preferred that the color and/or intensity of the light be adjustable and/or selectable.
[0025] The microscope is preferably a surgical microscope or a dental microscope.
[0026] Preferably, at least one passage opening (optical passage) has a surface configuration which prevents light from being emitted directly into the room and produces diffuse light emission. This may be achieved, for example, by a special geometric design (e.g., a sheet-metal cover) or optical design of the passage opening (for example, as a plate of milk glass), or by a special arrangement of the light source, or by a suitable surface roughness of, for example, the boundaries of the passage opening, which diffusely scatters the light of the light source provided for external illumination. Techniques for designing diffusely scattering surfaces or diffusely scattering light passage openings are generally known to those skilled in the art.
[0027] The optical passage may, in principle, be disposed anywhere on the microscope or the stand. Preferably, the passage opening is disposed on the microscope body or on a parallelogram linkage support.
[0028] The at least one optical passage is preferably configured as a gap or slot on the microscope body or the stand. Preferably, provision is made for a plurality of narrow slots or gaps.
[0029] Preferably, at least one of the passage openings is closed with a transparent cover so as, for example, to prevent even the smallest quantities of dust particles or other types of air pollution particles from entering the microscope or its components. This may advantageously be achieved by designing the cover itself as a diffuser for homogenizing the emerging light. However, it is also possible to dispose a diffuser inside of the microscope body or the stand in the vicinity of the light source.
[0030] The light sources preferably used for the indirect external illumination include inorganic light-emitting diodes (LED), organic light-emitting films (OLED), or what is known as “nanotubes”. It is also possible to use laser diodes, which may be advantageous because of the spectrum and orientation of their radiation.
[0031] It is preferred that the light color of the one or more light sources used for the external illumination also be variable and/or freely selectable. This is preferably done in an automatically controlled manner. Thus, it is possible, for example, to drive a plurality of different color LEDs alternatively or together to produce specific light colors.
[0032] Preferably, a specific light color and/or light intensity, or the change thereof, is assigned to a specific operating condition of the microscope, or its further above-mentioned mechanical components, and to changes in such an operating condition. Such operating conditions or operating mode indications to be displayed, and their respective changes, may refer, for example, to a magnification setting of the microscope, diopter settings of eyepieces of the microscope, the balancing of a stand of the microscope, the operational readiness of accessories, such as a camera, the making of a video recording, the remaining service life of illumination devices for object illumination, etc.
[0033] The balancing of the stand or microscope, or of other mechanical components or accessories of the microscope, may be accomplished using, for example, force sensors or torque sensors and may be associated with an electronic control system, which is also used to drive the light source(s) for the external illumination.
[0034] The remaining service life of light sources used in a microscope for object illumination may be determined, for example, from a table value read into the electronic control system of the external illumination system, for example, in accordance with a decay curve in tabular form, or based on an intensity value that is actually measured by a light-sensitive sensor and compared with stored reference values.
[0035] The operational readiness of electronic microscope accessories, such as a camera, may be deduced, for example, from an electronic feedback signal provided by such an accessory to the electronic control system. Therefore, the illumination system is advantageously associated with a microprocessor—or computer—controlled electronic control system.
[0036] Among a group of different operating conditions or operating mode indications to be displayed, particular preference is given to the following options:
the light color is used to indicate a magnification setting of the microscope; the light color is used to indicate the operating condition of a zoom system or the diopter setting of an eyepiece of the microscope; in the common case of a microscope having two eyepieces which are individually adjustable to different diopter settings, it is preferred that different light colors be producible on two different exterior sides of the microscope body or the stand.
[0040] Particularly advantageous embodiments of the present invention are those in which a plurality of operating conditions or operating mode indications of the microscope can be displayed simultaneously by one or more different light colors.
[0041] It is also advantageous if at least one sensor is provided which measures the color temperature and/or the light intensity of an external room lighting and adapts the color and/or intensity of the light from the light source accordingly via an electronic control system (e.g., chameleon function).
[0042] It may also be advantageous if the light colors produced by the illumination system for the external illumination are complementary to, for example, the color of an external room lighting.
[0043] Preferably, the microscope according to the present invention has an aesthetically appealing and compact design, which advantageously minimizes space requirements. This appearance may be further enhanced by the choice of light.
[0044] In addition to the technical advantages mentioned above, the present invention and the described embodiments provide further advantages for a user:
The exterior appearance of a microscope according to the present invention may be adapted to the surrounding space, for example, in a dentist's office. Prior art microscope bodies, stands, and support arms thereof, are known to have either untreated surfaces or surfaces treated with paints or other surface finishes. The use of indirect illumination by light that emerges from the unit through gaps or slots and is emitted indirectly to provide a surface appearance and an exterior appearance that are variable over time and/or variable in color has been unknown. Unlike conventional microscopes, the visually apparent space requirements of the unit in a doctor's office or an operating room can be influenced by means of the indirect external illumination. The present invention enables the appearance of a microscope, in particular a dental microscope or a surgical microscope, to be adapted to the needs of the user, or to the conditions of the room, by turning the external illumination on/off, by controlling its brightness and/or by selecting the color of its light. In an environment with high requirements on cleanliness, such as a doctor's or dentist's office, it is preferred to use blue light for the external illumination, because it is known from experience that blue light enhances the impression of hygiene and, in addition, because bacteria avoid blue tones. Blue tones are therefore bacteriophic. Moreover, light having shorter wavelengths down to the UV region has a bactericidal effect and, therefore, allows a microscope equipped in accordance with the present invention to be brought into a bactericidal condition when no people are present. Accordingly, in addition to the purely technical effects, it is also possible to change the coloring of surfaces without the need to replace components or covers, or apply new paint, which allows microscopes and stands to be dynamically adapted to the requirements of users or facilities.
[0049] Further embodiments of the present invention and variants thereof will become apparent from the dependent claims and the Figures.
[0050] The list of reference numerals is part of the disclosure.
[0051] The present invention is schematically described in more detail by way of example and with reference to Figures.
BRIEF DESCRIPTION OF THE DRAWING VIEWS
[0052] The Figures are described collectively. Identical reference numerals denote identical components; reference numerals having different indices indicate functionally identical or similar components. In the drawing,
[0053] FIG. 1 is a view showing the arrangement of a first exemplary embodiment of a dental microscope which is mounted on a stand in such a way that it can be adjusted in three degrees of freedom, said stand including a base provided with rollers and a vertical pole on which there are arranged three support arms, the dental microscope being mounted on the third support arm, and the entire arrangement being located in a room which can be illuminated;
[0054] FIG. 2 is an enlarged view of the dental microscope shown in FIG. 1 ;
[0055] FIG. 3 is a vertical sectional view of the housing body of the dental microscope, taken in the plane of line III-III in FIG. 2 and showing an open light exit opening on each of the two sides;
[0056] FIG. 4 is a vertical sectional view of the housing body similar to that of FIG. 3 , but showing an open light exit opening on the left side and a different light exit opening on the right side, the latter being closed dust-tight with a transparent plate as a light-diffusing body;
[0057] FIG. 5 is a vertical sectional view of the housing body similar to those of FIGS. 3 and 4 , but showing the two light passage openings covered with diffusing glass plates;
[0058] FIG. 6 is a side view of a modified housing body of the dental microscope shown in FIG. 1 ;
[0059] FIG. 7 is a vertical sectional view of the housing body of the dental microscope, taken in the plane of line VII-VII in FIG. 6 ;
[0060] FIG. 8 is a vertical sectional view similar to FIG. 7 , showing a further, modified housing body of a dental microscope, in which the light exit openings are provided with light shield sections for adjustment of their width;
[0061] FIG. 9 is a vertical sectional view taken in the plane of line IX-IX in FIG. 1 and showing the illumination arrangement on the stand in the region of the second support arm, which is in the form of a parallelogram support arm;
[0062] FIG. 10 is a view of a variant of the upper portion of the stand shown in FIG. 1 , in which the first support arm, which is pivotally attached to the stand pole, is provided with an indirect illumination system;
[0063] FIG. 11 is a vertical sectional view taken in the plane of line XI-XI in FIG. 10 and showing the indirect illumination system in the form of two rows of light sources arranged along the sides;
[0064] FIG. 12 is a view of a variant of the embodiment of FIG. 11 , showing only a single, central row of light sources; and
[0065] FIG. 13 is a view of the dental microscope corresponding to FIG. 12 , partially cut away and in cross section, illustrating the light exit at the rear.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0066] Referring to FIG. 1 , a dental microscope 1 is mounted on a stand 2 in such a way that it can be adjusted in three degrees of freedom. Stand 2 includes a rolling base 3 , a pole 4 , a first support arm 5 , a second support arm 6 , and a third support arm 7 . Support arms 5 , 6 , 7 are linked together by joints 8 and 9 .
[0067] The entire arrangement is set up in a room 11 which is used as a treatment room and provided with what is referred to as external room lighting 12 . Dental microscope 1 includes a head portion 13 which carries an eyepiece 14 and is mounted on microscope body 15 .
[0068] As is shown particularly in FIGS. 2 and 3 , light sources 17 , which may be in the form of three LEDs, are arranged in cavity 16 of microscope body 15 , the rays of light from said light sources emerging from the walls in a more or less downward direction through passage openings 18 formed in the sides and being partly reflected at inclined wall sections 19 a. As a result, both the side walls 19 of microscope body 15 and their surroundings in room 11 are discreetly illuminated, which positively influences the appearance of microscope 1 and affects the treatment environment and the position of the microscope in an ergonomically favorable manner, even in a semi-darkened room 11 .
[0069] A sensor 21 mounted on microscope body 15 measures the light intensity provided in room 11 by external room lighting 12 and is capable of controlling the color and intensity of the light from light source 17 via an electronic control system according to corresponding, predetermined parameters.
[0070] The light intensity of light sources 17 can also be controlled manually, for example, using a rotary knob 22 on microscope body 15 .
[0071] As is shown particularly in FIG. 3 , light rays 17 a from light sources 17 emerge downwardly here and are reflected into room 11 by an the inclined section 19 a of wall 19 , so that they illuminate both microscope body 15 and room 11 .
[0072] FIG. 4 shows two variants of light passage openings. The left side shows the variant of FIG. 3 , which features an open, slotted opening. This embodiment is suitable, for example, for illuminating room 11 away from the practitioner, making it possible to increase the brightness of the background to maximum levels. Light exit opening 24 shown on the right side is closed dust-tight with a transparent ground glass plate 25 which has light-diffusing properties and is inserted in a pocket or recess 26 flush with the exterior of wall 19 . In this manner, wall 19 of microscope body 15 turns into a large-area luminous element which illuminates room 11 with diffuse, homogenized light, preferably toward the side of the practitioner. Alternatively, it is possible to equip both walls 19 ; i.e., the one on the left and the one on the right in FIG. 4 , with a ground glass plate 25 as a luminous element having light-diffusing properties.
[0073] FIG. 5 shows an embodiment in which light passage openings 27 are closed dust-tight with cover plates 28 . These cover plates may have diffusing properties, and may thus be capable of diverging the light rays into sets of rays 17 c . A portion of rays 17 c may enter room 11 directly, while another portion is initially reflected at inclined wall sections 19 a.
[0074] Light sources 17 are arranged in a row within cavity 16 , here, for example, along a central line and such that said row of light sources does not extend into the area of the optical path of the microscope. Inner surfaces 29 of walls 19 and 31 of cavity 16 may be provided with reflectors or reflective coatings.
[0075] FIG. 6 shows in greater detail the portion of control panel 32 of microscope body 15 . In particular, for example, reference numeral 33 denotes the adjustment means of objective 37 , numeral 34 designates the control of light sources 17 , and numeral 35 denotes the control of room lighting 12 . Here, opening 18 for the exit of light is in the form of a longitudinal slot extending obliquely and convexly from top left to bottom right.
[0076] Referring to FIG. 7 , transparent light-guiding elements 36 are inserted in passage openings 18 on both sides between walls 19 , 19 a. These light-guiding elements provide a dust-tight seal on the one hand and, on the other hand, produce diverging light rays 17 b, and thus homogenized illumination, because of their diffusing properties.
[0077] As shown in FIGS. 6 and 8 , passage openings 18 may be provided with angle sections 38 to provide a means for adjusting the width B of passage openings 18 .
[0078] FIG. 1 and FIGS. 9 through 12 illustrate the arrangement of light sources 17 for indirect illumination on support arms 6 and 5 .
[0079] Referring in particular to FIGS. 1 and 9 , support arm 6 is configured as a parallelogram linkage arm which ensures constant vertical guidance during height adjustment of microscope 1 . The parallelogram linkage arm is formed by two arm members arranged parallel to one another. The upper arm member is denoted by 41 , while the lower arm member is denoted by 42 .
[0080] A U-shaped covering 43 including a bottom web 44 and two lateral flanges 45 and 46 is mounted to hub 8 a ( FIG. 1 ) of joint 8 in such a way that bottom web 44 is located under lower arm member 42 at a distance 47 therefrom.
[0081] The resulting clearance 49 accommodates indirect illumination means in the form of light sources 17 , which are arranged in such a way that two rows of light sources 17 direct indirect light radiation 51 upwardly through gaps 48 between support arm 6 , which is formed by arm members 41 and 42 , and lateral flanges 45 and 46 , thereby also illuminating the side surfaces of the two arm members 41 and 42 .
[0082] The indirect illumination means on first support arm 5 are configured similar to those mentioned above. Referring to FIGS. 10 and 11 , first support arm 5 is provided in its lower region with a U-shaped covering 52 which follows the tapering design of support arm 5 .
[0083] Provided on bottom web 53 are two rows of light sources 17 which emit light upwardly through narrow gaps 54 , respectively. Inner surfaces 55 of the covering are reflective, which enables the sets of indirect light rays 56 to travel upwardly and exit to the outside as multiply reflected rays, thereby also illuminating the side walls of first support arm 5 . At the right end portion ( FIG. 10 ), covering 52 projects beyond support arm 5 , forming a gap 57 , so that indirect light can also exit in this region.
[0084] FIG. 12 is a view of a variant of the embodiment of FIG. 11 , showing only a single strip of light sources 17 arranged centrally along bottom web 53 of U-shaped covering 52 . Here, the sets of light rays 56 are multiply reflected at underside 58 of support arm 5 and inner upper side 59 of bottom web 53 in directions toward two sides.
[0085] As illustrated in the partially cut away view of FIG. 13 , a light exit opening 18 is also provided at the rear of the microscope body 15 . In particular, rear walls 61 and 62 are offset from each other, forming and bounding a further slotted opening 63 . Thus, the microscope body is provided on three sides with passage openings 18 , 63 , 18 for indirect light exit.
LIST OF REFERENCE NUMERALS
[0086] 1 microscope, preferably a dental microscope
[0087] 2 stand
[0088] 3 base
[0089] 4 pole
[0090] 5 first support arm
[0091] 6 second support arm
[0092] 7 third support arm
[0093] 8 joint
[0094] 8 a hub of 8
[0095] 9 joint
[0096] 11 room
[0097] 12 room lighting (referred to as external room lighting)
[0098] 13 head portion of 1
[0099] 14 eyepiece
[0100] 15 microscope body
[0101] 16 cavity of 15
[0102] 17 light sources (LEDs)
[0103] 17 a light rays (direct reflection)
[0104] 17 b light rays (homogenized light)
[0105] 17 c light rays (divergent)
[0106] 18 passage openings (in the form of slots in 19 )
[0107] 19 walls
[0108] 19 a inclined wall section
[0109] 21 sensor
[0110] 22 rotary knob for light control
[0111] 24 light exit opening
[0112] 25 transparent ground glass plate (having light-diffusing and homogenizing properties)
[0113] 26 pocket, recess, retaining receptacle
[0114] 27 light passage opening
[0115] 28 cover plate
[0116] 29 inner surfaces (reflective)
[0117] 31 wall of 15 (at the top)
[0118] 32 control panel
[0119] 33 adjustment means for objective 37
[0120] 34 control for light source 17
[0121] 35 control for room lighting 12
[0122] 36 light-guiding elements (having diffusing properties)
[0123] 37 objective
[0124] 38 angle section (for the adjustment of B)
[0125] 41 upper arm member of 6
[0126] 42 lower arm member of 6
[0127] 43 U-shaped covering
[0128] 44 bottom web of 43
[0129] 45 lateral flange of 43
[0130] 46 lateral flange of 43
[0131] 47 distance
[0132] 48 gap
[0133] 49 clearance
[0134] 51 indirect light radiation
[0135] 52 covering
[0136] 53 bottom web
[0137] 54 gap
[0138] 55 surface
[0139] 56 sets of light rays
[0140] 57 gap
[0141] 58 underside
[0142] 59 upper side
[0143] 61 upper rear wall of 15
[0144] 62 lower rear wall of 15
[0145] 63 slotted opening
[0146] B width of opening 18 ( FIG. 8 )
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The present invention relates to a microscope ( 1 ), preferably a dental microscope, including a microscope body ( 15 ) and a stand ( 2 ) formed by a plurality of components to provide a supporting function or to enable positioning of the microscope ( 1 ) in the room ( 11 ), the microscope body ( 15 ) and the stand ( 2 ) having cavities ( 16 ) therein. It is a feature of the present invention that at least one cavity ( 16 ) of the microscope body ( 15 ) and/or the stand ( 2 ) has a light source ( 17 ) provided therein whose light ( 17 a, 17 b, 17 c ) can pass outwardly through passage openings ( 18, 24, 27 ).
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TECHNICAL FIELD
[0001] This present invention belongs to the field of road engineering, discloses a waterborne polymer modified emulsified asphalt mixture and the preparation method thereof, and particularly relates to a waterborne polyurethane modified emulsified asphalt concrete, a waterborne acrylic resin modified emulsified asphalt concrete, and a waterborne epoxy resin modified emulsified asphalt micro-surfacing mixture, and preparation methods thereof.
BACKGROUND ART
[0002] Conventional cold-mixed asphalt mixtures can achieve mixing construction at normal temperature to some extent so as to reduce the consumption of energy. However, cold-mixed asphalt mixtures have poor pavement performance, which fail to satisfy the requirements of modern road surfaces on asphalt materials and can be only used for low-quality road surface pavements or small-range repairing.
[0003] A waterborne polyurethane emulsion refers to a polyurethane which uses water as a dispersion medium and is free of or contains little amount of organic solvent in the system, and inherits excellent properties of solvent-type polyurethanes such as good low-temperature resistance, good abrasion resistance, high adhesion, etc., while it has the advantages of no pollution, good safety and reliability, good compatibility, easiness of modification, etc. It has gradually substituted solvent-type polyurethanes and is widely used in coatings, adhesives, fabric coatings and finishing agents, leather finishing agents, paper surface treating agents, fiber surface treating agents, etc. As an emulsified asphalt modifier, it has good physical and chemical properties and can significantly improve the pavement performance of emulsified asphalt.
[0004] Patent CN201110188772.9 discloses a waterborne polyurethane epoxy resin modified emulsified asphalt, which is formed by forming a polyurethane epoxy resin by a reaction with epoxy chloropropane or an epoxy resin after the chain extension of isocyanate with a polyol, forming a waterborne polyurethane epoxy resin by the association with a polyether polyol emulsifier, an auxiliary and water, modifying an emulsified asphalt, and curing with a modified fatty amine epoxy resin curing agent. It has a complicated process of synthesis and a lot of influential factors, and is difficult to ensure the uniformity; and meanwhile, the content of waterborne polyurethane is too low, which insufficiently contributes to the strength, and the application performance of this material is not evaluated in this patent.
[0005] An acrylate monomer has a carbon-carbon unsaturated double bond and forms an acrylate resin through a polymerization reaction. Acrylate resin does not only have very high photostability, thermal stability, and chemical stability, but also has the advantages of excellent weather resistance, corrosion resistance, chemical resistance, stain resistance, high adhesion, etc. Also, it has the features of abundant sources of raw materials and relatively low cost. In the wider sense, a waterborne acrylic resin comprises a waterborne acrylic resin emulsion, a waterborne acrylic resin dispersion in water, and an waterborne acrylic resin solution in water. They possess important applications in building coatings, but have not been used in roads yet.
[0006] As an asphalt modifier, the waterborne acrylic resin emulsion has good physical and chemical properties, and may improve the resistance of asphalt to corrosion by acids, alkalis, and organic solvents, improve high-temperature and low-temperature properties of asphalt, reduce the sensitivity of asphalt to temperature, increase the elasticity of asphalt, reduce aging tendency of asphalt, improve the adhesion of asphalt to stone materials, and improve the fatigue resistance of asphalt, so as to overall improve the pavement performance of emulsified asphalt. In recent years, there have been related studies in China, for example, Chinese Patent Application No. 201410023492.6 discloses a preparation method of an acrylic resin emulsified asphalt, which is studied mainly aiming at the technical problems that emulsified asphalt has long drying time and poor water resistant properties, and is mainly a water-resistant emulsified asphalt material. Chinese Patent Application No. 201410023481.8 discloses a preparation method of a urea resin emulsified asphalt, which has long reaction time and complex operation required for the synthesis of the urea resin emulsified asphalt.
[0007] After years' normal operation of a highway, rut and cracks will occur on part of the road surface. Although the function of the road surface is not influenced transitorily, utilization properties of the road surface will be reduced and the useful life will be shortened, if treatment is not timely performed.
[0008] Micro-surfacing is the highest form of an emulsified asphalt slurry overlay, which is a preventive curing technical measure developed on the basis of slurry seals, and is suitable for the preventive curing of important traffic roads, such as highways, city main roads, airport runways, etc. Micro-surfacing may improve slip resistance, repair slight surface unevenness and rut, prevent infiltration of water, and prevent aging and loosening of the road surface, so as to significantly improve utilization properties of the road surface and effectively elongate the useful life of the road surface; as a preventive maintenance technology, micro-surfacing may also be directly used for a surface wearing course of a newly built road so as to reduce the use of expensive stone materials, to decrease construction cost, and to significantly reduce the occurrence of early water damage; and furthermore, micro-surfacing further has the advantages of good convenience for construction, low construction cost, short time to open traffic, etc., and has a very wide prospect for application.
[0009] Micro-surfacing is a thin layer structure, wherein a polymer modified emulsified asphalt, a mineral aggregate, water, and an additive are mixed in a certain weight ratio and paved on a road surface by specialized equipment and the traffic is opened rapidly. It has high requirements for constituent materials: firstly, the aggregate used must be firm, wear resistant, and clean, and type II or type III gradation is typically used as the gradation of the stone material; and secondly, in order to ensure a better adhesion between the asphalt and the stone material, a cationic emulsified asphalt is typically used, and polymer modification is needed, and SBR latex or SBS is typically used for modification, so as to ensure that a micro-surfacing overlay may still achieve a relatively long useful life even under the action of heavy traffic.
[0010] As an emulsified asphalt modifier, the waterborne epoxy resin itself has good physical and chemical properties and can significantly improve the pavement performance of emulsified asphalt. However, pH is required to be adjusted to about 2-3 in the preparation process of a cationic emulsified asphalt, while the addition of a waterborne epoxy resin emulsion containing an amine-type curing agent will disrupt the equilibrium system of the cationic emulsified asphalt, leading to the failure of the effect of emulsification, and has a significant phenomenon of caking.
[0011] Current studies in the art are mainly focusing on the modified emulsified asphalt material itself, while studies on waterborne polymer modified emulsified asphalt mixtures have not been prevalent yet. The emulsified asphalt mixture said herein refers to a mixture containing emulsified asphalt used in engineering, particularly road engineering, which may be, for example, used for asphalt concrete pavement materials, asphalt road surface repair materials, slurry seals for curing, micro-surfacing, asphalt mortar for high-speed railways, etc.
[0012] However, in the field of road engineering, there remains a need for developing a waterborne polymer modified emulsified asphalt mixture having a simple preparation method and good properties.
SUMMARY OF THE INVENTION
[0013] The object of this present invention is to provide a novel waterborne polymer modified emulsified asphalt mixture for pavement and the preparation method thereof, with respect to the above problems present in the prior art. In one aspect, an object of this present invention is to provide a waterborne polymer modified emulsified asphalt concrete and the preparation method thereof. An waterborne polymer has better compatibility and stability after being mixed with an emulsified asphalt, and by the action of the self-crosslinking curing of the waterborne polymer after being mixed with an aggregate, forms a high-performance composite system having a spatial network structure, which has the functions of reinforcing, infiltration resistance, and chemical resistance, and may be evaporated and cured under the condition of normal temperature without generation of alligator cracks. In another aspect, an object of this present invention is to provide a waterborne polymer modified emulsified asphalt mixture used for micro-surfacing. It uses a waterborne polymer to modify an anionic emulsified asphalt, which thereby has the good properties of abrasion resistance, water damage resistance, and rut resistance.
[0014] An embodiment of this invention provides a waterborne polyurethane emulsified asphalt concrete, comprising raw materials: a mineral aggregate, an emulsified asphalt, and a waterborne polyurethane emulsion, wherein the weight ratio of the mineral aggregate, the waterborne polyurethane emulsion, and the emulsified asphalt is 100:1-20:7-20.
[0015] In the above, the mineral aggregate is basalt or limestone.
[0016] Particularly, the mineral aggregate is composed of a crude aggregate, a fine aggregate, and a filler, wherein the weight ratio of the crude aggregate, the fine aggregate, and the filler is 30-70:30-70:5-10, the crude aggregate has a nominal particle size of δ>4.75 mm, the fine aggregate has a nominal particle size of δ≦4.75 mm, the filler has a nominal particle size of δ≦0.075 mm.
[0017] In the above, the waterborne polyurethane emulsion is an emulsified liquid or dispersion of waterborne polyurethane, which has a solid content of 30%-70%.
[0018] Particularly, the waterborne polyurethane emulsion may be a linear molecule type polyurethane emulsion or a crosslinking type polyurethane emulsion.
[0019] In the above, the emulsified asphalt has a solid content of 40%-75%.
[0020] Particularly, the preparation of the emulsified asphalt comprises preparing the emulsified asphalt, comprising the steps as follows:
[0021] 1) mixing water and an emulsifier, stirring at 55-65° C., and sufficiently dissolving to obtain a uniform emulsion;
[0022] 2) heating an asphalt to 120-160° C.; and
[0023] 3) pouring the heated asphalt into the uniform emulsion for emulsification with an emulsification time of 2-5 min;
[0024] wherein the weight ratio of the asphalt:the water:the emulsifier is 40-80:25-60:1-3.
[0025] Particularly, the emulsifier in step 1) is one or more of an anionic emulsifier, a cationic emulsifier, or a nonionic emulsifier.
[0026] A plurality of emulsifiers having the same polarity may be used in combination; and a nonionic emulsifier may also be used in combination with an anionic emulsifier or a cationic emulsifier.
[0027] Particularly, step 1) further comprises controlling pH value of the uniform emulsion at 11.5-12.5 by using a sodium hydroxide buffer when the emulsifier is an anionic emulsifier; and step 1) further comprises controlling pH value of the uniform emulsion at 2-3 by using a hydrochloric acid buffer when the emulsifier is cationic emulsifier.
[0028] An embodiment of this invention provides a method for the waterborne polyurethane emulsified asphalt concrete described above, comprising the steps as follows:
[0029] 1) mixing a waterborne polyurethane emulsion and an emulsified asphalt, and uniformly stirring to obtain a waterborne polyurethane modified emulsified asphalt for stand-by; and
[0030] 2) adding the waterborne polyurethane modified emulsified asphalt to a mineral aggregate, uniformly stirring, and curing, so as to obtain a waterborne polyurethane emulsified asphalt concrete;
[0031] wherein the time of stirring in step 1) is 2-10 min; and
[0032] wherein the time of stirring in step 2) is 60-300 s.
[0033] An embodiment of this invention provides a method for the waterborne polyurethane emulsified asphalt concrete described above, comprising: uniformly stirring a mineral aggregate, an emulsified asphalt, and a waterborne polyurethane emulsion, and curing, so as to obtain a waterborne polyurethane emulsified asphalt concrete;
[0034] wherein the time of stirring is 30-300 s.
[0035] The waterborne polyurethane emulsified asphalt concrete of this present invention may be used in the preparation of asphalt concrete pavement materials, asphalt road surface repair materials, slurry seals for curing, micro-surfacing, asphalt mortar for high-speed railways, etc.
[0036] An embodiment of this invention provides a waterborne acrylic resin emulsified asphalt concrete, comprising:
[0037] a mineral aggregate; and
[0038] a waterborne acrylic resin modified emulsified asphalt mixed and stirred with the mineral aggregate;
[0039] wherein the ratio of parts by weight of the mineral aggregate to the waterborne acrylic resin modified emulsified asphalt is 100:5-40.
[0040] In the above, the mineral aggregate is basalt or limestone, or a stone material which satisfies current technical standards and specifications.
[0041] Particularly, the mineral aggregate is composed of a crude aggregate, a fine aggregate, and a filler, wherein the weight ratio of the crude aggregate, the fine aggregate, and the filler is 30-70:30-70:5-10, the crude aggregate has a nominal particle size of δ>4.75 mm, the fine aggregate has a nominal particle size of δ≦4.75 mm, the filler has a nominal particle size of δ≦0.075 mm.
[0042] In the above, the waterborne acrylic resin modified emulsified asphalt comprises:
[0043] a soap liquid produced by mixing and stirring water and an emulsifier;
[0044] a monomer mixture and an initiator used to be added to the soap liquid to form a mixed liquid; and
[0045] an asphalt added to the mixed liquid;
[0046] In the above, during the addition of the monomer mixture and initiator to the emulsion, stirring is performed at a temperature of 65-85° C.; and the monomer mixture is dropwise added, the initiator is added in batches after dissolved with deionized water, stirring is continued for 10-30 min after the dropwise addition of the monomer mixture is complete, and then the pH of the mixed liquid is adjusted to 10-12;
[0047] wherein the asphalt is added to the mixed liquid when heated to 100-170° C.
[0048] Particularly, the ratio of parts by weight of the soap liquid, the monomer mixture, the initiator, and the asphalt is 41-73 of the soap liquid, 30-60 of the monomer mixture, 0.3-0.7 of the initiator, and 40-80 of the asphalt.
[0049] In the above, 1-3 parts of the emulsifier and 40-70 parts of deionized water are mixing and stirred to dissolve the emulsifier in water to produce the soap liquid.
[0050] Particularly, the emulsifier is an anionic emulsifier, including but not limited to, dodecyl sodium sulfate, dodecyl sodium sulfonate or dodecyl sodium benzene sulfonate.
[0051] Particularly, the speed of stirring is 500-1000 r/min.
[0052] In the above, the monomer mixture is dropwise added to the emulsion, the initiator is added to the emulsion in batches after dissolved with deionized water, and stirring is performed at a temperature of 65-85° C. for 2-5 min.
[0053] Particularly, the speed of stirring is 500-1000 r/min.
[0054] Particularly, the monomer mixture is a mixture of any two or more of acrylic acid, n-butyl acrylate, methyl methacrylate, ethyl methacrylate, lauryl acrylate, and acrylamide.
[0055] Particularly, the initiator is a persulfate, including but not limited to ammonium persulfate, potassium persulfate, and sodium persulfate.
[0056] Particularly, stirring is continued for 10-30 min after the dropwise addition of the monomer mixture is complete.
[0057] In the above, the pH of the mixed liquid is adjusted to 10-12.
[0058] Particularly, the pH of the mixed liquid is adjusted to 10-12 by using an alkaline solution.
[0059] Particularly, the alkaline solution is preferably a sodium hydroxide solution.
[0060] In the above, the asphalt is heated to 100-170° C. and is slowly added to the mixed liquid, and stirring is continuously performed to obtain a waterborne acrylic resin modified emulsified asphalt.
[0061] Particularly, the speed of stirring is 1000-3000 r/min.
[0062] In the above, the mineral aggregate and the waterborne acrylic resin modified emulsified asphalt are mixed, uniformly stirred, and cured to obtain the waterborne acrylic resin emulsified asphalt concrete.
[0063] Particularly, the time of stirring is 30-300 s.
[0064] In the above, the waterborne acrylic resin emulsified asphalt concrete is prepared by the method as follows:
[0065] an emulsifier and water is mixed and uniformly stirred to prepare a soap liquid; the monomer mixture is dropwise added to the soap liquid, the initiator is added to the soap liquid in batches after dissolved with deionized water, and stirring is performed at a temperature of 65-85° C.; stirring is continued for 10-30 min after the dropwise addition of the monomer mixture is complete, and then the pH of the mixed liquid is adjusted to 10-12; the asphalt heated to 100-170° C. is added to the mixed liquid with pH adjusted to 10-12, and stirring is uniformly performed to obtain a waterborne acrylic resin emulsified asphalt; the waterborne acrylic resin emulsified asphalt and the mineral aggregate are mixed, uniformly stirred, and cured to obtain the waterborne acrylic resin emulsified asphalt concrete.
[0066] The use of the waterborne acrylic resin modified emulsified asphalt may improve high-temperature and low-temperature properties of asphalt, reduce the sensitivity of asphalt to temperature, increase the elasticity of asphalt, reduce aging tendency of asphalt, improve the adhesion of asphalt to stone materials, and improve the fatigue resistance of asphalt.
[0067] An embodiment of this invention provides an acrylic resin emulsified asphalt, comprising:
[0068] a mineral aggregate; and
[0069] a waterborne acrylic resin and an emulsified asphalt mixed and stirred with the mineral aggregate;
[0070] wherein the ratio of parts by weight of the mineral aggregate, the waterborne acrylic resin, and the emulsified asphalt is 100:1-20:4-20.
[0071] In the above, the mineral aggregate is basalt or limestone, or a stone material which satisfies current technical standards and specifications.
[0072] Particularly, the mineral aggregate is composed of a crude aggregate, a fine aggregate, and a filler.
[0073] Particularly, the weight ratio of the crude aggregate, the fine aggregate, and the filler is 30-70:30-70:5-10.
[0074] In the above, the crude aggregate has a nominal particle size of δ>4.75 mm, the fine aggregate has a nominal particle size of δ≦4.75 mm, the filler has a nominal particle size of δ≦0.075 mm.
[0075] In the above, the emulsified asphalt comprises:
[0076] a soap liquid produced by mixing and stirring water and an emulsifier;
[0077] an asphalt used to be mixed with the soap liquid for emulsification;
[0078] wherein the pH of the soap liquid is adjusted to 10-12, the asphalt is heated to 100-170° C. and is added to the soap liquid, and emulsification is performed for 2-5 min.
[0079] Particularly, the ratio of parts by weight of the water, the emulsifier and the asphalt is 25-60:1-3:40-80.
[0080] Particularly, the water and the emulsifier are mixed and uniformly stirred at 30-70° C. to prepare the soap liquid.
[0081] Particularly, the emulsifier is an anionic emulsifier, including but not limited to, dodecyl sodium sulfate, dodecyl sodium sulfonate or dodecyl sodium benzene sulfonate.
[0082] In the above, the waterborne acrylic resin emulsion is an emulsion or a dispersion of a waterborne acrylic resin, having a solid content of 30-70%.
[0083] In the above, the mineral aggregate, the waterborne acrylic resin, and the emulsified asphalt are mixed, uniformly stirred, and cured to obtain the waterborne acrylic resin emulsified asphalt concrete.
[0084] Particularly, the time of stirring is 30-300 s.
[0085] In the above, the waterborne acrylic resin emulsified asphalt concrete is prepared by the method as follows:
[0086] an emulsifier and water is mixed and uniformly stirred to prepare a uniform soap liquid; the asphalt heated to 100-170° C. is added to the uniform soap liquid for emulsification to prepare an emulsified asphalt; the waterborne acrylic resin emulsion and the emulsified asphalt are mixed and uniformly stirred to obtain the a waterborne acrylic resin modified emulsified asphalt; the waterborne acrylic resin modified emulsified asphalt and the mineral aggregate are mixed, uniformly stirred, and cured to obtain the waterborne acrylic resin emulsified asphalt concrete.
[0087] The waterborne acrylic resin emulsified asphalt concrete of this present invention may be used in the preparation of asphalt concrete pavement materials, asphalt road surface repair materials, slurry seals for curing, micro-surfacing, asphalt mortar for high-speed railways, etc.
[0088] The waterborne polymer modified emulsified asphalt concrete of this present invention does not only have the advantages of conventional cold-mixed asphalt concrete, but also has good mechanical properties and stability as well as excellent pavement performance. The useful life of the road surface is greatly elongated and curing time is shortened so that traffic may be opened in 1-3 days. As a cold-mixed cold-paved asphalt concrete, it may be both used in pavement and repair of asphalt road surfaces and used in cold-mixed materials, slurry seals, micro-surfacing, etc. It has simple operation in production and construction as well as wide application, and is not limited by the conditions of transportation, repair, dispersion, etc. With respect to the hot-state technology for conventional hot-mixed hot-paved mixtures, energy consumption and the emission of toxic and harmful gases in the process of heating are reduced, and energy saving and emission reduction are achieved.
[0089] The waterborne polyurethane, which is used for the first time in this present invention, inherits excellent properties of solvent-type polyurethanes such as good low-temperature resistance, high abrasion resistance, high elasticity, high adhesion, etc., while it has the advantages of no pollution, good safety and reliability, good compatibility, easiness of modification, etc. By preparing the waterborne polyurethane emulsion with the waterborne polyurethane, the process is simple, no organic solvent is contained, and the compatibility and the stability with emulsified asphalt are good. By the action of the self-crosslinking curing of the waterborne polymer after being mixed with an aggregate, this present invention forms a high-performance composite system having a spatial network structure, which may be evaporated and cured under the environment of normal temperature without generation of alligator cracks and further provision and addition of a curing agent.
[0090] The waterborne acrylic acid modified emulsification asphalt emulsion, which is used for the first time in this present invention, has simple process, is free of organic solvent, has good compatibility, and forms a high-performance composite asphalt system having a spatial network structure by the action of the self-crosslinking curing of the waterborne acrylic acid, so as to greatly improve the properties of the emulsified asphalt and can be stably stored.
[0091] An embodiment of this invention provides a waterborne epoxy resin emulsified asphalt mixture used for micro-surfacing, characterized by comprising raw materials having the ratio of parts by weight as follows:
[0000]
a mineral aggregate
100
an anionic emulsified asphalt
10-15
a waterborne epoxy resin emulsion
0.5-12
water
6-11
[0092] Particularly, the mixture further comprises an additive, and the weight ratio of the mineral aggregate to the additive is 100:1-3.
[0093] In the above, the additive is one or more of cement, slaked lime, fiber, and a flocculant.
[0094] Particularly, the flocculant may be one of aluminum sulfate, iron sulfate, or polyacrylamide.
[0095] In the above, the mineral aggregate is composed of a crude aggregate, a fine aggregate, and a filler; wherein the weight ratio of the crude aggregate, the fine aggregate, and the filler is 10-30:55-85:5-15; the crude aggregate has a nominal particle size of 4.75 mm<δ≦9.5 mm; the fine aggregate has a nominal particle size of δ≦4.75 mm; the filler has a nominal particle size of δ≦0.075 mm.
[0096] In the above, the waterborne epoxy resin emulsion comprises a waterborne epoxy resin and a waterborne epoxy curing agent, and the weight ratio of the waterborne epoxy resin to the waterborne epoxy curing agent is 1:1-2.
[0097] Particularly, the waterborne epoxy resin emulsion further comprises water, and the ratio of the waterborne epoxy resin to the water is 1:1-5.
[0098] In the above, the waterborne epoxy resin is a water-soluble epoxy resin or a standard liquid epoxy resin having a solid content of 50-100%.
[0099] In the above, the waterborne epoxy curing agent is a polyamine-type curing agent emulsion having a solid content of 30-70%.
[0100] Particularly, the polyamine-type curing agent further comprises a modified polyamine-type curing agent.
[0101] An embodiment of this invention provides a preparation method of the mixture described above, characterized by comprising the steps as follows:
[0102] 1) preparing a mineral aggregate suitable for mixing;
[0103] 2) mixing a waterborne epoxy resin emulsion and an emulsified asphalt, and uniformly stirring to obtain a waterborne epoxy resin modified emulsified asphalt for stand-by;
[0104] 3) adding water to the prepared mineral aggregate, and sufficiently stirring to wet the mineral aggregate; and
[0105] 4) adding the waterborne epoxy resin modified emulsified asphalt to the wetted mineral aggregate, uniformly stirring, and curing, so as to obtain a micro-surfacing mixture;
[0106] wherein the weight ratio of the mineral aggregate, the waterborne epoxy resin emulsion, the emulsified asphalt and the water is 100:0.5-12:10-15:6-11;
[0107] wherein the time of stirring in step 4) is 30 s-180 s.
[0108] Particularly, the mineral aggregate suitable for mixing is prepared by mixing a crude aggregate, a fine aggregate and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler is 10-30:55-85:5-15; the crude aggregate has a nominal particle size of 4.75 mm<δ≦9.5 mm; the fine aggregate has a nominal particle size of δ≦4.75 mm; the filler has a nominal particle size of δ≦0.075 mm.
[0109] Particularly, the mineral aggregate suitable for mixing is formed by adding an additive after mixing a crude aggregate, a fine aggregate and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler is 10-30:55-85:5-15; the crude aggregate has a nominal particle size of 4.75 mm<δ≦9.5 mm; the fine aggregate has a nominal particle size of δ≦4.75 mm; the filler has a nominal particle size of δ≦0.075 mm, and the weight ratio of the mineral aggregate to the additive is 100:1-3.
[0110] Particularly, the waterborne epoxy resin emulsion is formed by mixing and stirring a waterborne epoxy resin and a waterborne epoxy curing agent with a stirring time of 5-10 min. In the above, the weight ratio of the waterborne epoxy resin and the waterborne epoxy curing agent is 1:1-2.
[0111] Particularly, the waterborne epoxy resin emulsion is prepared by mixing and stirring a waterborne epoxy resin and a waterborne epoxy curing agent for 5-10 min and then adding water. In the above, the weight ratio of the waterborne epoxy resin, the waterborne epoxy curing agent, and the water is 1:1-2:1-5.
[0112] An embodiment of this invention provides a preparation method of the mixture, comprising the steps as follows:
[0113] 1) preparing a mineral aggregate suitable for mixing;
[0114] 2) adding water to the prepared mineral aggregate, and sufficiently stirring to wet the mineral aggregate; and
[0115] 3) adding a waterborne epoxy resin emulsion and an emulsified asphalt to the wetted mineral aggregate, uniformly stirring, and curing, so as to obtain a micro-surfacing mixture;
[0116] wherein the weight ratio of the mineral aggregate, the additive, the waterborne epoxy resin emulsion, the emulsified asphalt and the water is 100:0.5-12:10-15:6-11;
[0117] wherein the time of stirring in step 3) is 30 s-180 s.
[0118] Particularly, the mineral aggregate suitable for mixing is prepared by mixing a crude aggregate, a fine aggregate and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler is 10-30:55-85:5-15; the crude aggregate has a nominal particle size of 4.75 mm<δ≦9.5 mm; the fine aggregate has a nominal particle size of δ≦4.75 mm; the filler has a nominal particle size of δ≦0.075 mm.
[0119] Particularly, the mineral aggregate suitable for mixing is prepared by adding an additive after mixing a crude aggregate, a fine aggregate and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler is 10-30:55-85:5-15; the crude aggregate has a nominal particle size of 4.75 mm<δ≦9.5 mm; the fine aggregate has a nominal particle size of δ≦4.75 mm; the filler has a nominal particle size of δ≦0.075 mm, and the weight ratio of the mineral aggregate to the additive is 100:1-3.
[0120] Particularly, the waterborne epoxy resin emulsion is formed by mixing and stirring a waterborne epoxy resin and a waterborne epoxy curing agent with a stirring time of 5-10 min. In the above, the weight ratio of the waterborne epoxy resin and the waterborne epoxy curing agent is 1:1-2.
[0121] Particularly, the waterborne epoxy resin emulsion is prepared by mixing and stirring a waterborne epoxy resin and a waterborne epoxy curing agent for 5-10 min and then adding water. In the above, the weight ratio of the waterborne epoxy resin, the waterborne epoxy curing agent, and the water is 1:1-2:1-5.
[0122] The advantageous effects of the waterborne epoxy resin emulsified asphalt mixture used for micro-surfacing in this present invention are shown by the following aspects:
[0123] 1) The anionic emulsified asphalt is used in micro-surfacing mixtures for the first time in this present invention. Anions have poor adhesion with stone materials and are typically not used in the preparation of micro-surfacing mixtures. Upon modification by a waterborne epoxy resin emulsion, they have not only improved adhesion with stone materials, but also have good compatibility and stability with the emulsified asphalt, while the phenomenon of caking generated by the amine-type curing agent in the cationic emulsified asphalt and the waterborne epoxy resin emulsion are prevented, and emulsifying properties are excellent.
[0124] 2) In the waterborne epoxy resin emulsified asphalt micro-surfacing mixture of this invention, a crosslinking reaction occurs between the waterborne epoxy resin and the waterborne epoxy curing agent under the condition of normal temperature to form a high-performance composite system having a spatial network structure, and the properties of the micro-surfacing such as abrasion resistance, water damage resistance, and rut resistance are greatly improved, so as to improve road-surface travelling quality and elongate the useful life of the road surface.
DESCRIPTION OF EMBODIMENTS
[0125] This present invention will be further described below in conjunction with specific examples, and the advantages and features of this invention will be clearer with description. However, these examples are merely exemplary and will in no way limit the scope of this invention. It is to be understood the person skilled in the art that amendments or replacements may be performed on details and forms of the technical solutions of this present invention without departing from the spirit and scope of this invention, and all of these amendments and replacements fall in the scope of this invention.
Example I-1
Preparation of Emulsified Asphalt
[0126] Materials were prepared according to the following weight proportion:
[0000]
Asphalt
110
g
water
90
g
dodecyl sodium sulfonate
4
g
[0127] Water and dodecyl sodium sulfonate were mixed and stirred at 60° C. and were sufficiently dissolved to obtain a uniform emulsion, pH of the emulsion was controlled at 12 by using a sodium hydroxide buffer; an asphalt was heated to 140° C. and poured into the prepared uniform emulsion for emulsification with an emulsification time of 4 min; and the prepared emulsified asphalt had a solid content of 54%.
[0128] 2) Preparation of Waterborne Polyurethane Emulsified Asphalt Concrete
[0129] 100 g of the emulsified asphalt and 40 g of a waterborne polyurethane emulsion were mixed and sufficiently stirred by using a low-speed stirrer for 5 min to prepare a uniform nonviscous brown mixture, which was a waterborne polyurethane emulsification asphalt emulsion.
[0130] The waterborne polyurethane emulsification asphalt emulsion was placed in a mixing pot, 1000 g of a mineral aggregate was added, stirring was performed at normal temperature for 140 s, and curing was performed to obtain a waterborne polyurethane emulsified asphalt concrete.
[0131] In the above, the mineral aggregate was basalt; the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 60:40:8, the crude aggregate had a nominal particle size of >4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm.
[0132] In the above, the waterborne polyurethane emulsion was a commercially available linear molecule type waterborne polyurethane emulsion having a solid content of 55%.
Example I-2
1) Preparation of Emulsified Asphalt
[0133] Materials were prepared according to the following weight proportion:
[0000]
Asphalt
160
g
water
50
g
octylphenol polyoxyethylene ether
2
g
[0134] Water and octylphenol polyoxyethylene ether were mixed and stirred at 55° C., and were sufficiently dissolved to obtain a uniform emulsion; an asphalt was heated to 120° C. and poured into the prepared uniform emulsion for emulsification with an emulsification time of 5 min; and the prepared emulsified asphalt had a solid content of 75%.
2) Preparation of Waterborne Polyurethane Emulsified Asphalt Concrete
[0135] 200 g of the nonionic emulsified asphalt and 10 g of a waterborne polyurethane emulsion were mixed and sufficiently stirred by using a low-speed stirrer for 10 min to prepare a uniform nonviscous brown mixture, which was a waterborne polyurethane emulsification asphalt emulsion.
[0136] The waterborne polyurethane emulsification asphalt emulsion was placed in a mixing pot, 1000 g of a mineral aggregate was added, stirring was performed at normal temperature for 300 s, and curing was performed to obtain a waterborne polyurethane emulsified asphalt concrete.
[0137] In the above, the mineral aggregate was basalt; the aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 50:50:10, the crude aggregate had a nominal particle size of >4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm.
[0138] In the above, the waterborne polyurethane emulsion was a commercially available crosslinking type waterborne polyurethane emulsion having a solid content of 70%.
Example I-3
1) Preparation of Emulsified Asphalt
[0139] Materials were prepared according to the following weight proportion:
[0000]
Asphalt
40 g
Water
60 g
Cetyltrimethylammonium chloride
1 g
[0140] Water and cetyltrimethylammonium chloride were mixed and stirred at 65° C. and were sufficiently dissolved to obtain a uniform emulsion, pH of the emulsion was controlled at 3 by using a hydrochloric acid buffer; an asphalt was heated to 160° C.; the heated asphalt was poured into the prepared emulsion for emulsification with an emulsification time of 3 min; and the prepared emulsified asphalt had a solid content of 40%.
2) Preparation of Waterborne Polyurethane Emulsified Asphalt Concrete
[0141] 70 g of the cationic emulsified asphalt and 200 g of a waterborne polyurethane emulsion were mixed and sufficiently stirred by using a low-speed stirrer for 2 min to prepare a uniform nonviscous brown mixture, which was a waterborne polyurethane emulsification asphalt emulsion.
[0142] The waterborne polyurethane emulsification asphalt emulsion was placed in a mixing pot, 1000 g of a mineral aggregate was added, stirring was performed at normal temperature for 60 s, and curing was performed to obtain a waterborne polyurethane emulsified asphalt concrete.
[0143] In the above, the mineral aggregate was limestone; the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 70:30:5, the crude aggregate had a nominal particle size of >4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm.
[0144] In the above, the waterborne polyurethane emulsion was a commercially available linear molecule type waterborne polyurethane emulsion having a solid content of 40%.
Example I-4
1) Preparation of Emulsified Asphalt
[0145] Materials were prepared according to the following weight proportion:
[0000]
Asphalt
60 g
water
45 g
sodium dibutylnaphthalenesulfonate
3 g
[0146] Water and sodium dibutylnaphthalenesulfonate were mixed and stirred at 60° C. and were sufficiently dissolved to obtain a uniform emulsion, pH of the emulsion was controlled at 12 by using a sodium hydroxide buffer; an asphalt was heated to 150° C. and poured into the prepared emulsion for emulsification with an emulsification time of 2 min; and the prepared emulsified asphalt had a solid content of 47%.
2) Preparation of Waterborne Polyurethane Emulsified Asphalt Concrete
[0147] 1000 g of a mineral aggregate, 70 g of a cationic emulsified asphalt, and 10 g of a waterborne polyurethane emulsion were placed in a mixing pot, stirred at normal temperature for 30 s, and cured to obtain a waterborne polyurethane emulsified asphalt concrete;
[0148] wherein the mineral aggregate was limestone; the aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 50:30:5, the crude aggregate had a nominal particle size of >4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm.
[0149] In the above, the waterborne polyurethane emulsion was a commercially available linear molecule type waterborne polyurethane emulsion having a solid content of 50%.
Example I-5
1) Preparation of Emulsified Asphalt
[0150] Materials were prepared according to the following weight proportion:
[0000]
Asphalt
130
g
water
100
g
dodecyl sodium sulfate
3
g
octylphenol polyoxyethylene ether
3
g
[0151] Water, dodecyl sodium sulfate and octylphenol polyoxyethylene ether were mixed and stirred at 60° C. and were sufficiently dissolved to obtain a uniform emulsion, pH of the emulsion was controlled at 12 by using a sodium hydroxide buffer; an asphalt was heated to 145° C. and poured into the prepared uniform emulsion for emulsification with an emulsification time of 4 min; and the prepared emulsified asphalt had a solid content of 55%.
2) Preparation of Waterborne Polyurethane Emulsified Asphalt Concrete
[0152] 1000 g of a mineral aggregate, 200 g of a cationic emulsified asphalt, and 200 g of a waterborne polyurethane emulsion were placed in a mixing pot, stirred at normal temperature for 300 s, and cured to obtain a waterborne polyurethane emulsified asphalt concrete;
[0153] wherein the mineral aggregate was limestone; the aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 70:50:10, the crude aggregate had a nominal particle size of >4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm.
[0154] In the above, the waterborne polyurethane emulsion was a commercially available crosslinking type waterborne polyurethane emulsion having a solid content of 60%.
Comparative Example I-1
[0155] An emulsified asphalt was prepared according to the method of Example I-1. 150 g of this asphalt was placed in a mixing pot, 1000 g of a mineral aggregate was added, stirring was performed at normal temperature for 140 s, and curing was performed to obtain a cold-mixed emulsified asphalt concrete.
[0156] In the above, the mineral aggregate was basalt; the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 50:50:10, the crude aggregate had a nominal particle size of δ>4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm.
Comparative Example I-2
[0157] 69 g of an asphalt was heated to 165° C. and was added to 1000 g of an aggregate at 175° C., and mixing was performed at 170° C. to obtain a hot-mixed asphalt concrete.
[0158] In the above, the mineral aggregate was basalt; the aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 50:50:10, the crude aggregate had a nominal particle size of δ>4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm.
Test Example I-1
[0159] The waterborne polyurethane emulsified asphalt concretes prepared in Examples I-1 to I-5 and the emulsified asphalt concretes prepared in Comparative Examples I-1 and I-2 were molded into test pieces according to the specification “Standard Test Methods of Bitumen and Bituminous Mixture for Highway Engineering (JTG E20-2011)”, were cured, and the Marshall performance test was performed. The test results are as shown in Table 1.
[0000]
TABLE 1
Results of Marshall Performance Test
Technical
Comparative
Comparative
Example
Example
Example
Example
Example
requirements
Example I-1
Example I-2
I-1
I-2
I-3
I-4
I-5
Stability kN
≧8
3.67
9.94
19.08
11.09
17.91
7.83
28.04
Dynamic
≧800
1034.8
2145
48461.5
21000
24230.8
5218.3
64250.9
stability
(time/mm)
Maximal
≧2000
—
2515.9
6339.7
4488.8
4994.2
2085
8503.1
flexural strain
(με)
Cleavage
≧70
70%
86%
97%
95%
92%
75%
98%
strength
percentage
Note:
technical requirements are on the basis of “Standard Test Methods of Bitumen and Bituminous Mixture for Highway Engineering (JTG E20-2011)” T0709
[0160] It can be seen from Table 1 that the cold-mixed emulsified asphalt concrete prepared in Comparative Example I-1 has poor stability, none of indices thereof reaches the technical requirements, and can not be used for road pavement; upon the modification action of the waterborne polyurethane, both the stability and the dynamic stability of the waterborne polyurethane emulsified asphalt concretes prepared in Examples I-1 to I-5 are improved to 2 times more than those of the Comparative Example I-1 or more, demonstrating that the stability at high temperature is significantly superior to that of Comparative Example I-1; furthermore, since the molded rut board of the normal asphalt mixture in Comparative Example I-1 has poor mechanical strength and fails to be cut into qualified trabecular test pieces, the maximal flexural strain thereof can not be measured, while the waterborne polyurethane emulsified asphalt concretes prepared in Examples I-1 to I-5 have a maximal flexural strain up to 2000 or more, which satisfies the technical requirements for asphalt mixtures for pavement; and the cleavage strengths of Examples I-1 to I-5 are significantly higher than those of Comparative Example I-1 and the technical requirements, thereby demonstrating that the waterborne polyurethane emulsified asphalt concrete prepared in this present invention has better water stability.
[0161] Comparative Example I-2 is a conventional hot-mixed asphalt concrete, and it can be known from Table 1 that all indices of the waterborne polyurethane emulsified asphalt concrete of this invention are close to or even beyond those of a hot-mixed asphalt concrete.
[0162] In summary, the waterborne polyurethane emulsified asphalt concrete prepared in this present invention has high strength as well as good mechanical properties and stability, and achieves the technical effects of a hot-mixed asphalt concrete by using a process of cold mixing due to the modification action of the waterborne polyurethane. It is a road surface material having excellent pavement performance, and may be widely used in the preparation of asphalt concrete pavement materials, asphalt road surface repair materials, slurry seals for curing, micro-surfacing, asphalt mortar for high-speed railways, etc.
Example II-1
[0163] 2 g of dodecyl sodium sulfate was weighed and added to 50 g of deionized water, they were uniformly stirred at a speed of 1000/min, and dodecyl sodium sulfate was dissolved in water to prepare a soap liquid.
[0164] 45 g of a mixture of acrylic acid and n-butyl acrylate was weighed and dropwise added to the soap liquid, 0.5 g of ammonium persulfate was weighed and added to the soap liquid in batches after dissolved with a small amount of deionized water, they were stirred at a speed of 1000/min for 3 min, and the mixed liquid was kept at a temperature of 75° C.
[0165] After the dropwise addition of the monomers was complete, stirring was continued for 20 min to obtain a white viscous liquid, and pH of the mixed liquid was adjusted to 11 by using a 1% sodium hydroxide solution.
[0166] 60 g of an asphalt was weighed and slowly added to the above white viscous liquid after heated to 150° C., and was stirred at a speed of 2500/min for 3 min to obtain a waterborne acrylic resin modified emulsified asphalt.
[0167] 200 g of the prepared waterborne acrylic resin modified emulsified asphalt was weighed and placed in a mixing pot, 1000 g of a mineral aggregate was added, they were stirred at normal temperature for 150 s to obtain a waterborne acrylic resin emulsified asphalt concrete.
[0168] In the above, the mineral aggregate was basalt; the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 50:60:7, the crude aggregate had a nominal particle size of >4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm.
Example II-2
[0169] 3 g of dodecyl sodium sulfonate was weighed and added to 70 g of deionized water, they were uniformly stirred at a speed of 500/min, and were dissolved in water to prepare an emulsion.
[0170] 30 g of a mixture of methyl methacrylate and ethyl methacrylate was weighed and dropwise added to the emulsion, 0.7 g of potassium persulfate was weighed and added to the emulsion in batches after dissolved with a small amount of deionized water, they were stirred at a speed of 500/min for 2 min, and the mixed liquid was kept at a temperature of 65° C.
[0171] After the dropwise addition of the monomers was complete, stirring was continued for 30 min to obtain a white viscous liquid, and pH of the mixed liquid was adjusted to 12 by using a 1% sodium hydroxide solution.
[0172] 80 g of an asphalt was weighed and slowly added to the above white viscous liquid after heated to 100° C., and was stirred at a speed of 3000/min for 3 min to obtain a waterborne acrylic resin modified emulsified asphalt.
[0173] 400 g of the prepared waterborne acrylic resin modified emulsified asphalt was weighed and placed in a mixing pot, 1000 g of a mineral aggregate was added, they were stirred at normal temperature for 300 s to obtain a waterborne acrylic resin emulsified asphalt concrete.
[0174] In the above, the mineral aggregate was basalt; the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 30:50:6, the crude aggregate had a nominal particle size of >4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm.
Example II-3
[0175] 1 g of dodecyl sodium benzene sulfonate was weighed and added to 40 g of deionized water, they were uniformly stirred at a speed of 750/min, and dodecyl sodium benzene sulfonate was dissolved in water to prepare an emulsion.
[0176] 60 g of a mixture of acrylic acid, lauryl acrylate and acrylamide was weighed and dropwise added to the emulsion, 0.3 g of sodium persulfate was weighed and added to the emulsion in batches after dissolved with a small amount of deionized water, they were stirred at a speed of 750/min for 5 min, and the mixed liquid was kept at a temperature of 85° C.
[0177] After the dropwise addition of the monomers was complete, stirring was continued for 10 min to obtain a white viscous liquid, and pH of the mixed liquid was adjusted to 10 by using a 1% sodium hydroxide solution.
[0178] 40 g of an asphalt was weighed and slowly added to the above white viscous liquid after heated to 170° C., and was stirred at a speed of 1000/min for 3 min to obtain a waterborne acrylic resin modified emulsified asphalt.
[0179] 50 g of the prepared waterborne acrylic resin modified emulsified asphalt was weighed and placed in a mixing pot, 1000 g of a mineral aggregate was added, they were stirred at normal temperature for 30 s to obtain a waterborne acrylic resin emulsified asphalt concrete.
[0180] In the above, the mineral aggregate was basalt; the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 70:40:10, the crude aggregate had a nominal particle size of >4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm.
Example II-4
[0181] 3 g of dodecyl sodium benzene sulfonate was weighed and added to 60 g of deionized water, they were uniformly stirred at a temperature of 70° C., and dodecyl sodium benzene sulfonate was dissolved in water to prepare an emulsion; pH of the emulsion was adjusted to 12 by using a 1% sodium hydroxide solution; and 40 g of an asphalt was weighed and slowly added to the above emulsion after heated to 170° C., and emulsification was performed for 5 min to obtain an emulsified asphalt.
[0182] 40 g of the emulsified asphalt, 200 g of a waterborne acrylic resin emulsion, and 1000 g of a mineral aggregate were mixed and stirred at normal temperature for 30 s to obtain a waterborne acrylic resin emulsified asphalt concrete.
[0183] In the above, the mineral aggregate was basalt; the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 60:30:9, the crude aggregate had a nominal particle size of >4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm; the waterborne acrylic resin emulsion was a commercially available linear molecule type waterborne acrylic resin emulsion having a solid content of 30%.
Example II-5
[0184] 1 g of dodecyl sodium sulfonate was weighed and added to 25 g of deionized water, they were uniformly stirred at a temperature of 30° C., and dodecyl sodium sulfonate was dissolved in water to prepare an emulsion; pH of the emulsion was adjusted to 10 by using a 1% sodium hydroxide solution; and 80 g of an asphalt was weighed and slowly added to the above emulsion after heated to 100° C., and emulsification was performed for 2 min to obtain an emulsified asphalt.
[0185] 200 g of the emulsified asphalt, 10 g of a waterborne acrylic resin emulsion, and 1000 g of a mineral aggregate were mixed and stirred at normal temperature for 300 s to obtain a waterborne acrylic resin emulsified asphalt concrete.
[0186] In the above, the mineral aggregate was basalt; the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 40:70:5, the crude aggregate had a nominal particle size of >4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm; the waterborne acrylic resin emulsion was a commercially available linear molecule type waterborne acrylic resin emulsion having a solid content of 70%.
Example II-6
[0187] 2 g of dodecyl sodium sulfate was weighed and added to 40 g of deionized water, they were uniformly stirred at a temperature of 50° C., and dodecyl sodium sulfate was dissolved in water to prepare an emulsion; pH of the emulsion was adjusted to 11 by using a 1% sodium hydroxide solution; and 60 g of an asphalt was weighed and slowly added to the above emulsion after heated to 140° C., and emulsification was performed for 3 min to obtain an emulsified asphalt.
[0188] 100 g of the emulsified asphalt, 100 g of a waterborne acrylic resin emulsion, and 1000 g of a mineral aggregate were mixed and stirred at normal temperature for 100 s to obtain a waterborne acrylic resin emulsified asphalt concrete.
[0189] In the above, the mineral aggregate was basalt; the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 50:50:8, the crude aggregate had a nominal particle size of δ>4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm; the waterborne acrylic resin emulsion was a commercially available linear molecule type waterborne acrylic resin emulsion having a solid content of 55%.
Comparative Example II-1
[0190] A cold-mixed emulsified asphalt concrete was prepared in the same manner as that of Example II-6, except that the waterborne acrylic resin emulsion was not added.
Comparative Example II-2
[0191] 60 g of an asphalt was weighed and slowly added to 1000 g of a mineral aggregate after heated to 150° C., and stirring was performed for at normal temperature for 150 s to obtain a hot-mixed asphalt concrete.
[0192] In the above, the mineral aggregate was basalt; the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler, the weight ratio of the crude aggregate, the fine aggregate, and the filler was 50:60:7, the crude aggregate had a nominal particle size of δ>4.75 mm, the fine aggregate had a nominal particle size of δ≦4.75 mm, the filler had a nominal particle size of δ≦0.075 mm.
Test Example II-1
[0193] The waterborne acrylic resin emulsified asphalt concretes prepared in Examples II-1 to II-6, the hot-mixed asphalt concrete prepared in Comparative Example II-1, and the cold-mixed emulsified asphalt concrete prepared in Comparative Example II-2 were molded into test pieces according to the specification “Standard Test Methods of Bitumen and Bituminous Mixture for Highway Engineering (JTG E20-2011)”, were cured, and the Marshall performance test was performed. The test results are as shown in Table 2.
[0000]
TABLE 2
Results of Marshall Performance Test
Technical
Comparative
Comparative
Example
Example
Example
Example
Example
Example
requirements
Example II-1
Example II-2
II-1
II-2
II-3
II-4
II-5
II-6
Marshall
≧8
3.67
9.94
33.76
20.58
8.59
45.34
10.07
31.25
stability
kN
Note:
technical requirements are on the basis of “Standard Test Methods of Bitumen and Bituminous Mixture for Highway Engineering (JTG E20-2011)” T0709
[0194] It can be seen from Table 2 that the cold-mixed emulsified asphalt concrete prepared in Comparative Example II-1 has poor stability, the index of Marshall stability thereof does not reach the technical requirements, and can not be used for road pavement; and upon the modification action of the waterborne acrylic resin, the Marshall stability of the waterborne acrylic resin emulsified asphalt concretes prepared in Examples II-1 to II-6 are improved to 2 times more than those of the Comparative Example II-1 or more, and that of Example II-4 may be even up to 12 times or more.
[0195] Comparative Example II-2 is a conventional hot-mixed asphalt concrete, and it can be known from Table 2 that all indices of the waterborne acrylic resin emulsified asphalt concrete of this invention are close to or even beyond those of a hot-mixed asphalt concrete.
[0196] In summary, the waterborne acrylic resin emulsified asphalt concrete prepared in this present invention has high strength and good mechanical properties, achieves the technical effects of a hot-mixed asphalt concrete by the modification action of the waterborne acrylic resin by using a process of cold mixing. It is a road surface material having excellent pavement performance, and may be widely used in the preparation of asphalt concrete pavement materials, asphalt road surface repair materials, slurry seals for curing, micro-surfacing, asphalt mortar for high-speed railways, etc.
Example III-1
1. Preparation of Waterborne Epoxy Resin Emulsion
[0197] 100 g of a waterborne epoxy resin and 150 g of diethylene triamine were mixed, the mixed emulsion was sufficiently stirred by using a low-speed stirrer for 7.5 min, and the mixture was allowed to be uniform to obtain a waterborne epoxy resin emulsion.
[0198] In the above, The waterborne epoxy resin was a standard liquid epoxy resin having a solid content of 75%;
[0199] wherein diethylene triamine had a solid content of 50%.
2. Preparation of Epoxy Emulsified Asphalt
[0200] 50 g of the waterborne epoxy resin emulsion was poured into 120 g of an anionic emulsified asphalt, and uniform stirring was performed to prepare a waterborne epoxy emulsified asphalt.
3. Preparation of Micro-Surfacing Mixture
[0201] Materials were prepared according to the following weight proportion:
[0000]
mineral aggregate
1000
g
water
80
g
waterborne epoxy emulsified asphalt
170
g
[0202] Water was added to the mineral aggregate, uniform stirring was performed at normal temperature, the waterborne epoxy resin emulsified asphalt was further added, and stirring was continued for 100 s to obtain a micro-surfacing mixture.
[0203] In the above, the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler; wherein the weight ratio of the crude aggregate, the fine aggregate, and the filler was 20:40:10; the crude aggregate had a nominal particle size of 4.75 mm<δ≦9.5 mm; the fine aggregate had a nominal particle size of δ≦4.75 mm; the filler had a nominal particle size of δ≦0.075 mm.
Example III-2
1. Preparation of Waterborne Epoxy Resin Emulsion
[0204] 10 g of a waterborne epoxy resin and 20 g of polyamide-650 were mixed, the mixed emulsion was sufficiently stirred by using a low-speed stirrer for 5 min, and the mixture was allowed to be uniform to obtain a waterborne epoxy resin emulsion.
[0205] In the above, The waterborne epoxy resin was a water-soluble epoxy resin having a solid content of 50%;
[0206] wherein polyamide-650 had a solid content of 70%.
3. Preparation of Epoxy Emulsified Asphalt
[0207] 10 g of the waterborne epoxy resin emulsion was poured into 120 g of an anionic emulsified asphalt, and uniform stirring was performed to prepare a waterborne epoxy emulsified asphalt.
4. Preparation of Micro-Surfacing Mixture
[0208] Materials were prepared according to the following weight proportion:
[0000]
mineral aggregate
1000
g
cement
20
g
water
60
g
waterborne epoxy emulsified asphalt
130
g
[0209] The cement was added to the mineral aggregate, uniform stirring was performed at normal temperature, water was further added, stirring was continued to form a uniform mixture, the waterborne epoxy resin emulsified asphalt was further added, and stirring was continued for 30 s to obtain a micro-surfacing mixture.
[0210] In the above, the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler; wherein the weight ratio of the crude aggregate, the fine aggregate, and the filler was 10:55:5, the crude aggregate had a nominal particle size of 4.75 mm<δ≦9.5 mm; the fine aggregate had a nominal particle size of δ≦4.75 mm; the filler had a nominal particle size of δ≦0.075 mm.
Example III-3
1. Preparation of Waterborne Epoxy Resin Emulsion
[0211] 100 g of a waterborne epoxy resin and 100 g of N,N′-dihydroxyethyl diethylene triamine were mixed, 300 g of water was further added, the mixed emulsion was sufficiently stirred by using a low-speed stirrer for 10 min, and the mixture was allowed to be uniform to obtain a waterborne epoxy resin emulsion.
[0212] In the above, The waterborne epoxy resin was a water-soluble epoxy resin having a solid content of 100%;
[0213] wherein N,N′-dihydroxyethyl diethylene triamine has a solid content of 30%.
4. Preparation of Epoxy Emulsified Asphalt
[0214] 10 g of the waterborne epoxy resin emulsion was poured into 100 g of an anionic emulsified asphalt, and uniform stirring was performed to prepare a waterborne epoxy emulsified asphalt.
5. Preparation of Micro-Surfacing Mixture
[0215] Materials were prepared according to the following weight proportion:
[0000]
mineral aggregate
1000
g
mineral fiber
30
g
water
110
g
waterborne epoxy emulsified asphalt
110
g
[0216] The mineral fiber was added to the mineral aggregate, uniform stirring was performed at normal temperature, water was further added, stirring was continued to form a uniform mixture, the waterborne epoxy resin emulsified asphalt was further added, and stirring was continued for 180 s to obtain a micro-surfacing mixture.
[0217] In the above, the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler; wherein the weight ratio of the crude aggregate, the fine aggregate, and the filler was 30:85:15; the crude aggregate has a nominal particle size of 4.75 mm<δ≦9.5 mm; the fine aggregate has a nominal particle size of δ≦4.75 mm; the filler has a nominal particle size of δ≦0.075 mm.
Example III-4
1. Preparation of Waterborne Epoxy Resin Emulsion
[0218] 100 g of a waterborne epoxy resin and 150 g of polyamide 650 were mixed, 100 g of water was further added, the mixed emulsion was sufficiently stirred by using a low-speed stirrer for 7.5 min, and the mixture was allowed to be uniform to obtain a waterborne epoxy resin emulsion.
[0219] In the above, the waterborne epoxy resin was a water-soluble epoxy resin having a solid content of 75%;
[0220] wherein polyamide 650 had a solid content of 50%.
2. Preparation of Micro-Surfacing Mixture
[0221] Materials were prepared according to the following weight proportion:
[0000]
mineral aggregate
1000
g
aluminum sulfate
10
g
water
110
g
waterborne epoxy resin emulsion
120
g
anionic emulsified asphalt
100
g
[0222] Aluminum sulfate was added to the mineral aggregate, water was added after uniform stirring, the waterborne epoxy resin emulsion and the emulsified asphalt were further added after uniform stirring, and stirring was performed for 120 s to obtain a micro-surfacing mixture.
[0223] In the above, the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler; wherein the weight ratio of the crude aggregate, the fine aggregate, and the filler was 10:85:5, the crude aggregate has a nominal particle size of 4.75 mm<δ≦9.5 mm; the fine aggregate has a nominal particle size of δ≦4.75 mm; the filler has a nominal particle size of δ≦0.075 mm.
Example III-5
1. Preparation of Waterborne Epoxy Resin Emulsion
[0224] 10 g of a waterborne epoxy resin and 20 g of polyamide 650 were mixed, 50 g of water was further added, the mixed emulsion was sufficiently stirred by using a low-speed stirrer for 5 min, and the mixture was allowed to be uniform to obtain a waterborne epoxy resin emulsion.
[0225] In the above, The waterborne epoxy resin was a water-soluble epoxy resin having a solid content of 100%;
[0226] wherein polyamide 650 had a solid content of 70%.
2. Preparation of Micro-Surfacing Mixture
[0227] Materials were prepared according to the following weight proportion:
[0000]
mineral aggregate
1000
g
polyacrylamide
20
g
water
60
g
waterborne epoxy resin emulsion
5
g
anionic emulsified asphalt
150
g
[0228] A water solution of an emulsifier was added to the mineral aggregate, water was added after uniform stirring, the waterborne epoxy resin emulsion and the emulsified asphalt were further added after uniform stirring, and stirring was performed for 50 s to obtain a micro-surfacing mixture.
[0229] In the above, the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler; wherein the weight ratio of the crude aggregate, the fine aggregate, and the filler was 30:55:15; the crude aggregate has a nominal particle size of 4.75 mm<δ≦9.5 mm; the fine aggregate has a nominal particle size of δ≦4.75 mm; the filler has a nominal particle size of δ≦0.075 mm.
Comparative Example III-1
[0230] Materials were prepared according to the following weight proportion:
[0000]
mineral aggregate
1000
g
water
80
g
SBR modified emulsified asphalt
170
g
[0231] wherein the content of SBR comprised 4% of the emulsified asphalt, and the SBR modified emulsified asphalt had a solid content of 50%.
[0232] Water was added to the mineral aggregate, a uniform mixture was formed by stirring, the SBR modified emulsified asphalt was further added, and stirring was continued for 100 s to obtain the one of interest.
[0233] In the above, the mineral aggregate was composed of a crude aggregate, a fine aggregate, and a filler; wherein the weight ratio of the crude aggregate, the fine aggregate, and the filler was 20:40:10; the crude aggregate has a nominal particle size of 4.75 mm<δ≦9.5 mm; the fine aggregate has a nominal particle size of δ≦4.75 mm; the filler has a nominal particle size of δ≦0.075 mm.
Test Example III-1
Determination of Wear Resistant Property
[0234] A 1 h wet rut abrasion value was used to evaluate the abrasion resistant property of micro-surfacing, and a smaller 1 h wet rut abrasion value indicates a better abrasion resistant property. The method of determination was JTG E20-2011 “Standard Test Methods of Bitumen and Bituminous Mixture for Highway Engineering” T0752-2011. The test results are as shown in Table 3.
[0235] It can be known from Table 3 that the micro-surfacing mixture of this invention has significantly improved wear resistance compared to that of Comparative Example, and the 1 h wet rut abrasion value thereof is less than half of that of Comparative Example III-1.
Test Example III-2
Determination of Water Damage Resistant Property
[0236] A 6 d wet rut abrasion value was used to evaluate the abrasion resistant property of micro-surfacing, and a smaller 6 d wet rut abrasion value indicates a better abrasion resistant property. The method of determination was JTG E20-2011 “Standard Test Methods of Bitumen and Bituminous Mixture for Highway Engineering” T0752-2011. The test results can be seen in Table 3.
[0237] It can be known from Table 3 that the micro-surfacing mixture of this invention has significantly improved water damage resistant property compared to that of Comparative Example, and the 1 h wet rut abrasion value is reduced by more than 25% with respect to that of Comparative Example III-1.
Test Example III-3
Determination of Rut Resistant Property
[0238] A width deformation rate in a rut deformation test was used to evaluate the rut resistant property of micro-surfacing, and a smaller rut deformation rate indicates a better rut resistant property. The method of determination was JTG E20-2011 “Standard Test Methods of Bitumen and Bituminous Mixture for Highway Engineering” T0756-2011. The test results can be seen in Table 3.
[0239] It can be known from Table 3 that rut deformation rates of the micro-surfacing mixtures of this invention are all lower than that of Comparative Example III-1, in which the Example III-4 has the best effect, and the rut deformation rate is reduced by 34.61% compared to Comparative Example III-1.
[0000]
TABLE 3
Experiment Results of Micro-surfacing
Comparative
Evaluation indices
Example III-1
Example III-1
Example III-2
Example III-3
Example III-4
Example III-5
1 h wet rut abrasion value
450.6
66.5
83.5
201.2
54.7
89.1
(g/m 2 )
6 d wet rut abrasion value
780.6
240.6
351.9
560.2
180.7
453.9
(g/m 2 )
Rut deformation rate (%)
5.2
3.8
4.4
5.1
3.4
4.7
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This present invention discloses a waterborne polymer modified emulsified asphalt mixture and the preparation method thereof, and particularly relates to a waterborne polyurethane emulsified asphalt concrete, a waterborne acrylic resin emulsified asphalt concrete, and a waterborne epoxy resin emulsified asphalt micro-surfacing mixture, and preparation methods thereof. A mixture containing a waterborne polymer modified emulsified asphalt forms a high-performance composite system having a spatial network structure, and has good performance and simple preparation process.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 10/674,729, filed Sep. 30, 2003, which is a divisional of application Ser. No. 09/874,609, filed Jun. 5, 2001, now U.S. Pat. No. 6,652,577, which is a divisional of application Ser. No. 09/431,988, filed Nov. 2, 1999, now U.S. Pat. No. 6,240,978, which is a divisional of application Ser. No. 08/993,033, filed Dec. 18, 1997, now U.S. Pat. No. 5,993,483, which claims the benefit of European Patent Application No. 97202152.1, filed in the European Patent Office on Jul. 17, 1997, the contents of all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a stent for use in a body passageway, comprising a flexible self-expanding braided tubular wall being composed of helically wound wires and having proximal and distal ends. The invention also relates to a method for manufacturing such a stent.
[0003] A stent of the type as mentioned in the introduction is described for example in U.S. Pat. No. 4,655,771. The tubular wall is composed of several flexible thread elements each of which extends along a helix with the center line of the tubular wall as a common axis. The thread elements are arranged in two groups of opposite directions of winding crossing each other in a way to form a braided configuration. This is to impart to the tubular body the necessary stability for supporting a vessel. The diameter of the tubular wall can be changed by axial movement of the ends relative to each other. The stent is transluminally inserted into position in its radially compressed state and then subjected to expansion staying in place by a permanent pressure against the inner wall of the body passageway. The stability of the tubular body depends in general from the number of the thread elements, their diameter and material and from the braiding angle of the thread elements at their crossings. It is preferred to have the axially directed braiding angle being obtuse, i.e. larger than 90°, in order to obtain a large force in radial directions. But the braiding angle also influences the shortening of the stent, which is the reduction of the scent length upon conversion from its compressed to its expanded state. At a given diameter expansion the stent shortens less at braiding angles smaller than around 120° than at larger angles.
[0004] In the following stents with a braiding angle larger than about 120° are referred to as “normal-shortening” whereas stents having a braiding angle of less than about 120° are referred to as “less-shortening.” It is an advantage of less-shortening stents that they can be placed more accurately because the practitioner can better estimate the final positions of the stent ends after expansion. The less-shortening feature comes also to fruition when the stent is implanted in a moving hollow organ in which the stent is repeatedly radially compressed, such as in the esophagus, in the trachea or in a pulsating blood vessel. In those cases the reduced shortening of the stent is less traumatic for the inner wall of the hollow organ since the stent ends perform smaller axial movements than normal-shortening stents do. For the aforesaid reasons less-shortening stents are preferably implanted in ostium regions, for example in the aorta next to the entries into the renal arteries or in side branches. Exact placement capability and less axial movement of the stent ends reduce the risk of unwanted perturbation or obstruction of the blood flow by stent ends projecting into the ostium.
[0005] However, stents of the less-shortening type comprise smaller hoop strength compared to normal-shortening prostheses due to their smaller braiding angle. A consequence of the lower radial force is a reduction of the self fixation characteristics with the risk of a local axial displacement of the stent within the body passageway. Moreover, the stent is not stable enough to resist flattening if it is implanted in arched vessels. This means that a more or less strong deformation of the stent cross-section deviating from its original circular shape can partially close the stent.
[0006] In EP-A-O 775 471 an improved stent is disclosed comprising a flexible self expanding braided tubular wall having a proximal segment of smaller diameter and a distal segment of larger diameter and in-between an intermediate segment forming a truncated cone. A covering layer is arranged within the tubular wall. Although the document does not disclose any specific braiding angles the proximal segment will have a similar braiding angle as the above described less-shortening stent and the distal segment will have a larger braiding angle. The different geometry can be derived from the manufacturing methods as described in the document. The large-diameter segment serves as a migration anchor while the less-shortening segment with smaller diameter makes an easier and safer way through curves or at the end of for example a food pipe. But the less-shortening stent segment still has not sufficient shape stability for use in curved areas of body vessels. The cross-section of this segment may be deformed elliptically if bended in curved body vessels as it will occur generally for less-shortening stents. Moreover, because of the conical shape such a stent can be used only at particular areas, such as in food pipes. In addition, it is to be said that the used manufacturing methods are quite expensive.
[0007] All documents cited herein, including the foregoing, are incorporated herein by reference in their entireties for all purposes.
SUMMARY OF THE INVENTION
[0008] It is therefore an object of the present invention to improve a less-shortening stent such that it can be used universally, and more specifically in moving and/or in curved body passageways avoiding migration and flattening deformation thereof. A further object of the invention is to provide a stent which can be manufactured easier.
[0009] The term “elevation” has the meaning of an impression or bulge of the stent wall as well in the negative as in the positive sense, i.e. extending inwardly or outwardly of the tubular stent wall. Accordingly, the tubular wall has at least a local inwardly and/or outwardly formed elevation, whereby the wires are plastically deformed in a way that the number of degrees of freedom for their movement within the braiding is reduced. This means that the mesh cells defined by the braided wires are “frozen” by a reduced capability of the wires to rotate and shift relative to each other at their crossing points. The braided tubular wall retains its less-shortening feature and becomes more stable against radial deformation. A further advantage of the formed elevations is the possibility to make a short stent of the type mentioned in the introduction. Such stents are usually cut from the braiding blank and comprise an unwanted conical shape due to a memory effect from the braiding process. This shape can be converted into a cylindrical tube and conserved by forming elevations on the stent wall.
[0010] Where the elevations are distributed regularly over the tubular wall, the stent will be anchored firmly with the tissue of the body vessel without damaging. The homogeneity of the elevation distribution is for example preferred if the stent is to be implanted in a curved area of a body passageway.
[0011] More dense distribution of the elevations at the proximal and distal ends of the stent will provide higher stability at these areas for better anchoring thereof with the tissue of the body vessel. This embodiment is preferred if the stent is to be implanted in ostium positions for a safe fixation of the stent ends in order to prevent migration of the stent and disturbing for example the blood flow into a side branch through this ostium. Another preferred application of such a stent is the support of a vessel having a hard plaque stenosis whereby the stent comprises a higher density of elevations in the stenotic region.
[0012] In a preferred embodiment of the invention the elevations are formed outwardly so that they can serve as an anchor against stent migration by engaging into the inner vessel wall to be supported. Moreover, the deployment of such a stent with delivery devices as known in the art is enhanced since the retraction of the outer sheath is easier. This results from a reduced friction between the inside of the delivery sheath and the radially outwardly pressing stent touching the sheath only at the elevations.
[0013] In another preferred embodiment of the present invention the local elevations have an elongate shape which makes the manufacturing of such stents very easy by using wires to emboss the tubular wall. The elevations may have an arched cross-sectional shape. Preferably the height of the elevations are approximately one to two times the wire diameter of the braid.
[0014] These embossments or elevations can be formed in patterns helically on the tubular wall, where in a preferred embodiment the helical elevation pattern has a different pitch than the wires of the braid in order to deform as many wires as possible. The elevations may also be formed annularly or in an axial direction on the tubular wall depending on the desired effect. Where the elevations are placed annularly the stent wall comprises an improved radial stability, whereas elevations in axial directions impart to the stent a higher longitudinal stability which is especially useful for implantation in the airways.
[0015] The manufacturing method according to the present invention is determined by the steps of forming an elongate mandrel having at least one local outwardly bound elevation, forming an elongated tubular braid of spring steel having proximal and distal ends and an inner diameter commensurate with the diameter of the mandrel, engaging said tubular braid over said mandrel, heating the tubular braid on the mandrel, cooling the tubular braid and disengaging the braid from the mandrel. Preferably previous to the disengaging step the braid will be compressed in the axial direction.
[0016] In sum the present invention relates to a stent for use in a body passageway. A flexible self expanding braided tubular wall is composed of helically wound wires and has proximal and distal ends, wherein the tubular wall has at least a local inwardly and/or outwardly formed elevation. The local elevations may be distributed regularly over the tubular wall and distributed more densely at the proximal and distal ends. The local elevations of the stent may be formed outwardly and may have an elongated shape. The stent elevations may have an arched cross-sectional shape and/or a height of approximately one to two times of the diameter of the wires. The elevations may be formed helically on the tubular wall. The helical elevation may have a different pitch than the wires of the braid. The elevation may be formed annularly on the tubular wall or formed in an axial direction on the tubular wall.
[0017] The invention further relates to a method for manufacturing a stent by forming or providing an elongated mandrel having at least one local outwardly bound elevation; forming or providing an elongated tubular braid of spring steel having proximal and distal ends and an inner diameter commensurate with the diameter of the mandrel; engaging the tubular braid over the mandrel; heating the tubular braid over the mandrel; cooling the tubular braid; and disengaging the braid from the mandrel. Prior to disengaging the braid from the mandrel, the braid may be compressed in an axial direction. The steps of heating the tubular braid over the mandrel and cooling the tubular braid may be performed under vacuum condition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] These and other objects, features and advantages of the present invention will become readily apparent from the subsequent description, wherein the invention will be explained in further details with reference to the accompanying drawings which show, diagrammatically and by way of example only, preferred but still illustrative embodiments of the invention.
[0019] FIG. 1 shows a stent with a helical elevation in side view,
[0020] FIG. 2 shows a cross-sectional view according to line A-A in FIG. 1 ,
[0021] FIG. 3 shows a stent with a plurality of radial elevations in side view,
[0022] FIG. 4 shows a stent with a plurality of axial elevations in side view,
[0023] FIG. 5 shows the stent of FIG. 4 in front view according to arrow B,
[0024] FIG. 6 shows a stent similar to that in FIG. 1 , but with increased densities of elevations at its ends, and
[0025] FIG. 7 shows a stent similar to that in FIG. 3 , but with increased densities of elevations at its ends.
[0026] In the following description of the drawings the same reference numbers have been used for all figures if not mentioned otherwise.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The stent depicted in FIG. 1 comprises a flexible self expanding braided tubular wall 1 which is composed of a first plurality of parallel spring stainless steel wires 2 helically wound in a first direction crossing a second plurality of parallel spring stainless steel wires 3 helically wound in a second direction opposite to the first one. The braided structure assures contraction of the stent in the radial direction when the proximal and distal ends 4 and 5 of the stent are pulled away from one another as exemplified by arrows 6 , and self expansion of the stent in the radial direction when the pull according to arrows 6 is released. This configuration is well known in the art and needs no further explanation. Of course, other known braidings or patterns providing the same effect may be used.
[0028] The tubular wall 1 of the stent having a helical pattern of elevations 7 which is outwardly formed and has an angle of gradient or pitch slightly smaller than the angle of gradient or pitch of the steel wires 2 shown in the same winding direction. The elevations 7 have an elongate and arched cross-sectional shape. The height of the elevations 7 over the tubular wall 1 is about once or twice the diameter of the wires 2 or 3 of the braided configuration. The wires 2 and 3 may be made of a metallic material, e.g. stainless steel, which may be filled with a radiopaque core, or made of a thermoplastic polymer, such as polyesters, polyurethanes, polycarbonates, polysulphides, polypropylene, polyethylene or polysulphonates. Normally the diameter of the wires 2 and 3 lie within the range 0.01 to 0.5 mms. The helical elevation 7 provides a greater stability of the meshes of the braided tubular wall 1 , i.e. the parallel wires 2 and the parallel wires 3 will be prevented from moving apart at the crossing points 8 . Especially in the cross-sectional view of FIG. 2 it can be seen that wires 2 and 3 have been deformed locally in a tubular shape. The elevation pattern is normally distributed in a regular manner over the tubular wall 1 . Therefore a specific wire 2 or 3 will have several elevation areas over its whole length within the tubular wall 1 and a much greater stability of the wires 2 and 3 within the braid will be obtained. The elevation is further smooth curved, i.e. having a continuous smoothly inclining and declining curvature with the effect that the spring activity of the wires 2 and 3 will be reduced in the areas of the elevations. On the other hand the braiding angle between the wires 2 and 3 will be enlarged locally in the area of the elevations which will additionally enhance the mechanical stability of the tubular wall 1 . In fact, the meshes are immobilized or “frozen” at the crossing points of the wires 2 and 3 in the area of the elevation. By the frozen meshes the tubular wall 1 will obtain an enlarged shape stability which will resist the deforming forces of the body vessel. The elevation 7 will also reduce the tendency of the wires 2 and 3 to debraid at the proximal and distal ends 4 and 5 of the tubular wall 1 . Thus the aforementioned stent will have a greater form or shape stability if the tubular wall 1 will be bent in blood vessels with a strong curvature, i.e. the circular cross-section of the tubular wall 1 will be retained and not deformed to an elliptical one as can be observed with less-shortening stents.
[0029] Another possibility of providing elevations for stents according to the present invention is shown in FIG. 3 , where the stent having annular pattern of outwardly formed elevations 12 which, are equidistant and parallel to each other. Here also the stability of the stent has been improved over the well-known stents. If an annular pattern of elevations 12 will be provided near the proximal and distal ends 4 and 5 the tendency of debraiding of the wires 2 and 3 can be reduced further.
[0030] In FIG. 4 another example of a stent according to the invention is shown, wherein outwardly formed elevations 13 are provided in an axial direction on the tubular wall- 1 , which elevations 13 are also equidistant and parallel to each other. The front view of FIG. 5 shows that these elevations are also smoothly curved as in the previous examples. Since the wires 2 and 3 are intertwined with a relatively dense mesh the four patterns of elevations 13 as depicted in this example are sufficient to prevent debraiding at the proximal and distal ends 4 and 5 of the stent.
[0031] Although the elevations 7 , 12 and 13 in the examples of FIGS. 1, 3 and 4 are formed outwardly on the tubular wall 1 , they may also be formed inwardly on the tubular wall 1 or possibly provided in combination of outwardly and inwardly formed elevations.
[0032] As mentioned previously, more dense distributions of elevations at the proximal and distal ends of the stent will provide higher stability at these areas for better anchoring of the stent with the tissue of the body vessel. Also, in connection with FIG. 3 it is noted above that an annular elevation pattern 12 near the proximal and distal ends 4 and 5 can reduce the debraiding tendency. FIG. 6 shows a stent of the type shown in FIG. 1 , but with increased densities of elevations at the proximal and distal ends. FIG. 7 shows a stent of the type shown in FIG. 3 , but with annular elevation patterns near the proximal and distal ends 4 and 5 .
[0033] The manufacturing of the aforementioned stents is as follows:
[0034] Firstly the stent will be produced in the known manner, i.e. the wires 2 and 3 will be intertwined with a predetermined braiding angle and with a predetermined mesh size dependent from the wire cross-section. The braiding angle of the so formed stent will normally be between 100°and 120°. Thereafter the stent will be pushed over a cylindrical mandrel with a regular pattern of outwardly formed elevations like the helical shape of wires provided on the surface of the mandrel as will be used to form a stent according to FIG. 1 . The mandrel with the stent will then be heated up to process temperature, kept under process temperature for a certain period of time, and cooled down afterwards. The heating and cooling procedure is carried out under vacuum condition. In the case of stainless steel wires the thermal treatment may take up to sixteen hours, whereby the process temperature of 550° C. is maintained for about two hours. Then the stent will be pulled from the mandrel. In cases where the patterns of elevations are not axially directed as for the stent depicted in FIG. 4 , the tubular wall 1 may be compressed in order to enlarge the diameter thereof for an easier disengagement. In case of the helical pattern of the elevations the stent may also be unscrewed from the mandrel.
[0035] Although other patterns of elevations may also be used for the stents according to the invention the shown patterns are preferred since they guarantee a smooth outer surface of the tubular wall 1 which is especially important for stents to be used at delicate areas such as blood vessels in order not to damage the tissue. The helical shape and the annular shape of the pattern of elevations are preferred for stents used at the junction between the esophagus and the stomach as these will prevent much better the migration of the stent as in case of the axial pattern of elevations. In particular the elevations may also be formed inwardly instead of outwardly as shown and described above, i.e. the tubular stent wall having depressions. This may be advantageous if the body vessel to be repaired needs more support and a larger contact area with the stent.
[0036] Stents according to the present invention have a further advantage in that they can be handled easier in the flexible shaft of the positioning instrument since the friction between the stent and the inner wall thereof will be reduced. This applies more for the outwardly formed elevations as for the ones inwardly formed. But in both cases the friction will be reduced in comparison to conventional stents. Thus repositioning of stents with elevations as shown before has been improved also.
[0037] The above-described embodiments of the invention are merely descriptive of its principles and are not to be considered limiting. Further modifications of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention as defined by the following claims.
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A stent for use in a body passageway includes a plurality of wires braided to form a self-expanding braided tubular structure. The braided wires form braiding angles along a length of the tubular structure. A portion of the wires are plastically deformed to reduce foreshortening of the braided structure.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a Continuation application of U.S. patent application Ser. No. 09/324,382 filed Jun. 2, 1999, now U.S. Pat. No. 6,200,336 B1, which claimed priority from U.S. Provisional patent application Serial No. 60/087,661 filed Jun. 28, 1998.
TECHNICAL FIELD
This invention relates to medical devices, more particularly, to intraluminal devices.
BACKGROUND OF THE INVENTION
As minimally invasive techniques and instruments for placement of intraluminal devices have developed over recent years, the number and types of treatment devices have proliferated as well. Stents, stent grafts, occlusion devices, artificial valves, shunts, etc., have provided successful treatment for a number of conditions that heretofore required surgery or lacked an adequate solution altogether. Minimally invasive intravascular devices have especially become popular with the introduction of coronary stents to the U.S. market in the early 1990s. Coronary and peripheral stents have been proven to provide a superior means of maintaining vessel patency, however, they have subsequently been used in conjunction with grafts as a repair for abdominal aortic aneurysm, fibers or other materials as occlusion devices, and as an intraluminal support for artificial valves, among other uses.
Some of the chief goals in designing stents and related devices include providing sufficient radial strength to supply sufficient force to the vessel and prevent device migration. An additional concern in peripheral use, is having a stent that is resistant to external compression. Self-expanding stents are superior in this regard to balloon expandable stents which are more popular for coronary use. The challenge is designing a device that can be delivered to the target vessel in as small of a configuration as possible, while still being capable of adequate expansion. Self-expanding stents usually require larger struts than balloon expandable stents, thus increasing their profile. When used with fabric or other coverings that require being folded into a delivery catheter, the problem is compounded.
There exists a need to have a basic stent, including a fabric covering, that is capable of being delivered with a low profile, while still having a sufficient expansion ratio to permit implantation in larger vessels, if desired, while being stable, self-centering, and capable of conforming to the shape of the vessel.
SUMMARY OF THE INVENTION
The foregoing problems are solved and a technical advance is achieved in an illustrative multiple-sided intraluminal medical device comprised of a single piece of wire or other material having a plurality of sides and bends interconnecting adjacent sides. The bends can be coils, fillets, or other configurations to reduce stress and fatigue. The single piece of wire is preferably joined by an attachment mechanism, such as a piece of cannula and solder, to form a closed circumference frame. The device has a first configuration wherein the sides and bends generally lie within a single, flat plane. In an embodiment having four equal sides, the frame is folded into a second configuration where opposite bends are brought in closer proximity to one another toward one end of the device, while the other opposite ends are folded in closer proximity together toward the opposite end of the device. In the second configuration, the device becomes a self-expanding stent. In a third configuration, the device is compressed into a delivery device, such as a catheter, such that the sides are generally beside one another. While the preferred embodiment is four-sided, other polygonal shapes can be used as well.
In another aspect of the present invention, one or more barbs can be attached to the frame for anchoring the device in the lumen of a vessel. The barbs can be extensions of the single piece of wire or other material comprising the frame, or they can represent a second piece of material that is separately attached to the frame by a separate attachment mechanism. An elongated barb can be used to connect additional devices with the second and subsequent frames attached to the barb in a similar manner.
In still another aspect of the present invention, a covering, such as DACRON, PTFE, collagen, or other flexible material, can be attached to the device with sutures or other means to partially, completely, or selectively restrict fluid flow. When the covering extends over the entire aperture of the frame, the frame formed into the second configuration functions as an vascular occlusion device that once deployed, is capable of almost immediately occluding an artery. A artificial valve, such as that used in the lower legs and feet to correct incompetent veins, can be made by covering half of the frame aperture with a triangular piece of material. The artificial vein traps retrograde blood flow and seals the lumen, while normal blood flow is permitted to travel through the device. In related embodiments, the device can be used to form a stent graft for repairing damaged or diseased vessels. In a first stent graft embodiment, a pair of covered frames or stent adaptors are used to secure a tubular graft prosthesis at either end and seal the vessel. Each stent adaptor has an opening through which the graft prosthesis is placed and an elongated barb is attached to both another stent graft embodiment, one or more frames in the second configuration are used inside a sleeve to secure the device to a vessel wall.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 depicts a top view of one exemplary embodiment of the present invention;
FIG. 2 depicts a pictorial view of the embodiment of FIG. 1;
FIGS. 3 to 3 B depict a top view and enlarged, partial cross-sectional views of a second exemplary embodiment of the present invention;
FIG. 4 depicts a side view of the embodiment of FIG. 3 deployed in a vessel;
FIG. 5 depicts a enlarged partial view of the embodiment of FIG. 1;
FIG. 6 depicts a partially-sectioned side view of the embodiment of FIG. 1 inside a delivery system;
FIG. 7 depicts a top view of a third embodiment of the present invention;
FIG. 8 depicts a side view of the embodiment of FIG. 7 deployed in a vessel;
FIGS. 9-11 depict enlarged partial views of other embodiments of the present invention;
FIG. 12 depicts a top view of a fourth embodiment of the present invention;
FIGS. 13-14 depicts side views of the embodiment of FIG. 12;
FIG. 15 depicts a top view of a fifth embodiment of the present invention;
FIG. 16 depicts a side view of the embodiment of FIG. 15;
FIG. 17 depicts a side view of a sixth embodiment of the present invention;
FIG. 18 depicts an enlarged pictorial view of a seventh embodiment of the present invention; and
FIG. 19 depicts a top view of an eighth embodiment of the present invention.
DETAILED DESCRIPTION
The invention is further illustrated by the following (preceding) pictorial embodiments, which in no way should be construed as further limiting. The present invention specifically contemplates other embodiments not illustrated but intended to included in the appended claims.
FIG. 1 depicts a top view of one embodiment of the medical device 10 of the present invention comprising a frame 11 of resilient material, preferably metal wire made of stainless steel or a superelastic material (e.g., nitinol). While round wired is depicted in each of the embodiments shown herein, other types, e.g., flat, square, or triangular, may be used to form the frame. In the illustrative embodiment, the frame comprises a closed circumference 62 of a single piece 59 of material that is formed into a device 10 having a plurality of sides 13 interconnected by a series of bends 12 . The depicted embodiment includes four sides 13 of approximately equal length. Alternative embodiment include forming a frame into any polygonal shape, for example a pentagon, hexagon, octagon, etc. One alternative embodiment is shown in FIG. 19 that includes a four-sided frame 11 having the general shape of a kite with two adjacent longer sides 66 and two adjacent shorter sides 67 . In the embodiment of FIG. 1, the bends 12 interconnecting the sides 13 comprise a coil 14 of approximately one and a quarter turns. The coil bend produces superior bending fatigue characteristics than that of a simple bend 40 , as shown in FIG. 9, when the frame is formed from stainless steel and most other standard materials. The embodiment of FIG. 9 may be more appropriate, however, if the frame is formed from nitinol (NiTi) or other superelastic alloys, as forming certain type of bends, such as coil 14 , may actually decrease fatigue life of a device of superelastic materials. Therefore, the bend 12 should be of a structure that minimizes bending fatigue. Alternative bend 12 embodiments include a outward-projecting fillet 41 as shown in FIG. 10, and an inward-projecting fillet 42 comprising a series of curves 63 , as shown in FIG. 11 . Fillets are well known in the stent art as a means to reduce stresses in bends. By having the fillet extend inward as depicted in FIG. 11, there is less potential trauma to the vessel wall.
When using stainless steel wire, the size of the wire depends on the size of device and the application. An occlusion device, for example, preferably uses 0.010″ wire for a 10 mm square frame, while 0.014″ and 0.016″ wire would be used for 20 mm and 30 mm frames, respectively. Wire that is too stiff can damage the vessel, not conform well to the vessel wall, and increase the profile of the device.
Returning to FIG. 1, the single piece 59 of material comprising the frame 11 is formed into the closed circumference by securing the first and second ends 60 , 61 with an attachment mechanism 15 such as a piece of metal cannula. The ends 60 , 61 of the single piece 59 are then inserted into the cannula 15 and secured with solder 25 , a weld, adhesive, or crimping to form the closed frame 11 . The ends 60 , 61 of the single piece 59 can be joined directly without addition of a cannula 15 , such as by soldering, welding, or other methods to join ends 61 and 62 . Besides, joining the wire, the frame could be fabricated as a single piece of material 59 , by stamping or cutting the frame 11 from another sheet (e.g., with a laser), fabricating from a mold, or some similar method of producing a unitary frame.
The device 10 depicted in FIG. 1 is shown in its first configuration 35 whereby all four interconnections or bends 20 , 21 , 22 , 23 and each of the sides 13 generally lie within a single flat plane. To resiliently reshape the device 10 into a second configuration 36 , shown in FIG. 2, the frame 11 of FIG. 1 is folded twice, first along a diagonal axis 24 with opposite bends 20 and 21 being brought into closer proximity, followed by opposite bends 22 and 23 being folded together and brought into closer proximity in the opposite direction. The second configuration 36 , depicted in FIG. 2, has two opposite bends 20 , 21 oriented at the first end 68 of the device 10 , while the other opposite bends 22 , 23 are oriented at the second end 69 of the device 10 and rotated approximately 180° with respect to bends 20 and 21 when viewed in cross-section. The medical device in the second configuration 36 can be used as a stent 44 to maintain an open lumen 34 in a vessel 33 , such as a vein, artery, or duct. The bending stresses introduced to the frame 11 by the first and second folds required to form the device 10 into the second configuration 36 , apply radial force against the vessel wall 70 to hold the device 10 in place and prevent vessel closure. Absent any significant plastic deformation occurring during folding and deployment, the device in the second configuration 36 when removed from the vessel or other constraining means, will at least partially return to the first configuration 35 . It is possible to plastically form the device 10 into the second configuration 36 , such that it does not unfold when restraint is removed. This might be particularly desired if the device is made from nitinol or a superelastic alloy.
The standard method of deploying the medical device 10 in a vessel 33 , depicted in FIG. 6, involves resiliently forming the frame 11 into a third configuration 37 to load into a delivery device 26 , such as a catheter. In the third configuration 37 the adjacent sides 13 are generally beside each other in close proximity. To advance and deploy the device from the distal end 28 of the delivery catheter 26 , a pusher 27 is placed into the catheter lumen 29 , When the device 10 is fully deployed, it assumes the second configuration 36 within the vessel as depicted in FIG. 2 . The sides 13 of the frame, being made of resilient material, conform to the shape of the vessel wall 70 such that when viewed on end, the device 10 has a circular appearance when deployed in a round vessel.
A second embodiment of the present invention is depicted in FIG. 3 wherein one or more barbs 19 are included to anchor the device 10 following deployment. As understood, a barb can be a wire, hook, or any structure attached to the frame and so configured as to be able to anchor the device 10 within a lumen. The illustrative embodiment includes a first strut 17 with up to three other barbed struts 18 , 71 , 72 , indicated in dashed lines, representing alternative embodiments. As depicted in detail view FIG. 3A, in the combination 38 that comprises struts 17 and 18 , each strut is an extension of the single piece 59 of material of the frame 11 beyond the closed circumference 59 . The attachment cannula 15 secures and closes the single piece 59 of material into the frame 11 as previously described, while the first and second ends 60 , 61 thereof, extend from the cannula 15 , running generally parallel with the side 13 of the frame 11 from which they extend, each preferably terminating around or slightly beyond respective interconnections or bends 20 , 23 . To facilitate anchoring, the distal end of the strut 17 in the illustrative embodiment contains a bend or hook defining barb 19 .
Optionally, the tip of the distal end can be ground to a sharpened point for better tissue penetration. To add a third and fourth barb as shown, a double-barbed strut 39 comprising barbs 71 and 72 is attached to the opposite side 13 as defined by bends 21 and 22 . Unlike combination 38 , the double-barbed strut 39 , as shown in detail view FIG. 3B, comprises a piece of wire, usually the length of combination 38 , that is separate from the single piece 59 comprising the main frame 11 . It is secured to the frame by attachment mechanism 15 using the methods described for FIG. 1 . FIG. 4 depicts barb 19 of strut 17 engaging the vessel wall 70 while the device 10 is in the second, deployed configuration 36 . While this embodiment describes up to a four barb system, more than four can be used.
FIG. 7 depicts a top view of a third embodiment of the present invention in the first configuration 35 that includes a plurality of frames 11 attached in series. In the illustrative embodiment, a first frame 30 and second frame 31 are attached by a strut 16 that is secured to each frame by their respective attachment mechanisms 15 . The strut 16 can be a double-barbed strut 39 as shown in FIG. 3 (and detail view FIG. 3B) that is separate from the single pieces 59 comprising frames 30 and 31 , or the strut may represent a long extended end of the one of the single pieces 59 as shown in detail view FIG. 3 A. Further frames, such as third frame 32 shown in dashed lines, can be added by merely extending the length of the strut 16 . FIG. 8 depicts a side view of the embodiment of FIG. 7 in the second configuration 36 as deployed in a vessel 33 .
FIGS. 12-18 depict embodiments of the present invention in which a covering 45 comprising a sheet of fabric, collagen (such as small intestinal submucosa), or other flexible material is attached to the frame 11 by means of sutures 50 , adhesive, heat sealing, “weaving” together, crosslinking, or other known means. FIG. 12 depicts a top view of a fourth embodiment of the present invention while in the first configuration 35 , in which the covering 45 is a partial covering 58 , triangular in shape, that extends over approximately half of the aperture 56 of the frame 11 . When formed into the second configuration 36 as shown in FIGS. 13-14, the device 10 can act as an artificial valve 43 such as the type used to correct valvular incompetence. FIG. 13 depicts the valve 43 in the open configuration 48 . In this state, the partial covering 58 has been displaced toward the vessel wall 70 due to positive fluid pressure, e.g., normal venous blood flow 46 , thereby opening a passageway 65 through the frame 11 and the lumen 34 of the vessel 33 . As the muscles relax, producing retrograde blood flow 47 , as shown in FIG. 14, the partial covering 58 acts as a normal valve by catching the backward flowing blood and closing the lumen 34 of the vessel. In the case of the artificial valve 43 , the partial covering 58 is forced against the vessel wall to seal off the passageway 65 , unlike a normal venous valve which has two leaflets, which are forced together during retrograde flow. Both the artificial valve 43 of the illustrative embodiment and the normal venous valve, have a curved structure that facilitates the capture of the blood and subsequent closure. In addition to the triangular covering, other possible configurations of the partial covering 58 that result in the cupping or trapping fluid in one direction can be used.
Selecting the correct size of valve for the vessel ensures that the partial covering 58 properly seals against the vessel wall 70 . If the lumen 34 of the vessel is too large for the device 10 , there will be retrograde leakage around the partial covering 58 .
FIG. 15 depicts a top view of a fifth embodiment of the present invention in the first configuration 35 , whereby there is a full covering 57 that generally covers the entire aperture 56 of the frame 11 . When the device 10 is formed into the second configuration 36 , as depicted in FIG. 16, it becomes useful as an occlusion device 51 to occlude a duct or vessel, close a shunt, repair a defect, or other application where complete prevention of flow is desired. As an intravascular device, studies in swine have shown occlusion to occur almost immediately when deployed in an artery or the aorta with autopsy specimens showed thrombus and fibrin had filled the space around the device. The design of the present invention permits it to be used successfully in large vessels such as the aorta. Generally, the occlusion device should have side 13 lengths that are at least around 50% or larger than the vessel diameter in which they are to be implanted.
FIGS. 17-18 depict two embodiments of the present invention in which the device 10 functions as a stent graft 75 to repair a damaged or diseased vessel, such as due to formation of an aneurysm. FIG. 17 shown a stent graft 75 having a tubular graft prosthesis 54 that is held in place by a pair of frames 11 that function as stent adaptors 52 , 53 . Each stent adaptor 52 , 53 has a covering attached to each of the frame sides 13 which includes a central opening 55 through which the graft prosthesis 54 is placed and held in place from friction or attachment to prevent migration. One method of preventing migration is placement of a smaller device of the present invention at each end and suturing it to the covering. The stent adaptors 52 , 53 provide a means to seal blood flow while centering the graft prosthesis in the vessel. A long double-ended strut 39 connects of each stent adaptor 52 , 53 and includes barb assists to further anchor the stent graft 75 . In the embodiment depicted in FIG. 18, the covering 45 comprises an outer sleeve 64 that is held in place by first and second frames 30 , 31 that function as stents 44 to hold and seal the sleeve 64 against a vessel wall and maintain an open passageway 65 . In the illustrative embodiment, the stents 44 are secured to the graft sleeve 64 by sutures 50 that are optionally anchored to the coils 14 of the bends 12 . If the embodiment of FIG. 18 is used in smaller vessels, a single frame 11 can be used at each end of the stent graft 75 .
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A multiple-sided medical device comprises a closed frame of a single piece of wire or other resilient material and having a series of bends and interconnecting sides. The device has both a flat configuration and a second, folded configuration that comprises a self-expanding stent. The stent is pushed from a delivery catheter into the lumen of a duct or vessel. One or more barbs are attached to the frame of the device for anchoring or to connect additional frames. A covering of fabric or other flexible material such as DACRON, PTFE, or collagen, is sutured or attached to the frame to form an occlusion device, a stent graft, or an artificial valve such as for correcting incompetent veins in the lower legs and feet. A partial, triangular-shaped covering over the lumen of the device allows the valve to open with normal blood flow and close to retrograde flow.
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BACKGROUND OF THE INVENTION
Silicon Nitride has generated considerable interest as a potential replacement for metals in applications requiring high strength at elevated temperatures, good thermal shock resistance and high resistance to oxidation and corrosion.
It is well known that the properties of the densified body are greatly dependent on the density, and it has been found necessary to add sintering aids to Silicon Nitride in order to fully densify the body. Typically the sintering aids used are Al 2 O 3 , BeO, MgO, TiO 2 , ZrO 2 , HfO 2 , and the oxides of the Group III elements of the periodic table, Scandium, Yttrium, Lanthanum, Cerium, etc.
It is also known that these sintering aids combine with the SiO 2 which is normally present in the Silicon Nitride raw material to form grain boundary phases, which can be either crystalline or amphorous. The final product thus consists of grains of Si 3 N 4 , either in the alpha or beta crystalline form, surrounded by one or more grain boundary phases consisting of silicon, nitrogen, oxygen, and the sintering aids. The properties of the final product are greatly influenced by the composition and properties of this grain boundary phase(s).
Silicon nitride compositions for use as cutting tools have concentrated on improving the high temperature properties of strength, hardness, and oxidation resistance.
For example, U.S. Pat. No. 4,227,842 to Samanta relates to a silicon nitride cutting tool for machining cast iron having a composition containing silicon nitride, silicon oxide and yttrium oxide. This patent also mentions a Prior art cutting tool material set forth in Japanese Pat. No. 49-113803 (10-30-1974) by Kazutaka Ohgo which appears in Chemical Abstracts, Volume 84, 1976, page 286. According to this work, silicon nitride is sintered with a metal oxide spinel. The spinel is formed prior to sintering by mixing magnesium oxide and yttrium oxide and heating to the appropriate temperature.
U.S. Pat. No. 4,388,085 to Sarin, et al relates to a composite cutting tool having an intergranular refractory phase comprising silicon nitride, magnesium oxide, and silicon dioxide.
U.S. Pat. No. 4,073,845 to Buljan relates to a process for producing a silicon nitride composite from an amorphous silicon nitride powder and a sintering aid which includes magnesium oxide or yttrium oxide.
U.S. Pat. No. 4,280,973 to Moskowitz, et al relates to a process of making a silicon nitride cutting tool by cold pressing and then sintering a powder constituting at least 75% by weight silicon nitride, another powder selected from the group consisting from yttrium oxide, magnesium oxide, cerium oxide, zirconium oxide, and mixtures thereof, and an additional powder selected from the group consisting of aluminum oxide, tungsten carbide, tungsten silicide, tungsten, tantanium carbide and mixtures thereof.
U.S. Pat. No. 4,327,187 to Komatsu, et al relates to a process of making silicon nitride articles consisting of yttrium oxide, aluminum oxide, aluminum nitride, and another powder selected from the group of titanium oxide, magnesium oxide, and zirconium oxide.
It is generally accepted that Si 3 N 4 bodies made with MgO have inferior high temperature properties to those bodies made with Y 2 O 3 sintering aids. In many instances, the improvement in high temperature properties have been accompanied by the impairment of other properties. While the prior art recognizes the influence of grain boundary phases on the mechanical properties of silicon nitride compositions, the effect of grain boundary phase composition on the machining performance of silicon nitride cutting tools is incompletely understood. Notwithstanding the properties of the foregoing compositions, enhancement of the metal cutting performance of silicon nitride cutting tools remains a highly desirable object.
SUMMARY OF THE INVENTION
The present invention is directed to silicon nitride cutting tools having outstanding resistance to thermal and mechanical shock.
Tools of the present invention exhibit markedly improved performance in metal cutting applications, particularly in the interrupted machining or milling of ferrous and non-ferrous alloys, most particularly cast iron alloys, as compared to prior art silicon nitride or aluminum oxide cutting tools.
Further, the tools of the present invention are capable of being manufactured by hot pressing, pressureless sintering, overpressure sintering or sinter-hipping as desired.
It has been found that when Y 2 O 3 and MgO are used together in certain proportions, the densified Si 3 N 4 body has outstanding toughness in metal cutting applications, much more so than Si 3 N 4 bodies made with MgO or Y 2 O 3 singularly.
In accordance with the present invention, there is provided a silicon nitride cutting tool comprising a granular phase consisting essentially of silicon nitride and an intergranular amorphous phase consists essentially of magnesium oxide, yttrium oxide and silicon oxide. The weight percent of the constituents include magnesium oxide from about 0.5 to about 10, yttrium oxide from about 2.5 to about 10 percent, aluminum oxide at less than about 0.5 percent, and silicon oxide present in an amount less than about 2.5 percent. The ratio of yttrium oxide to magnesium oxide is from about 1:1 to about 7:1. The balance of the cutting tool consists essentially of beta-silicon nitride.
DETAILED DESCRIPTION
The silicon nitride compositions of the present invention are composed predominantly of silicon nitride in the beta or high temperature crystalline form. Preferably, the starting raw material Si 3 N 4 powder should be in the alpha (low temperature) crystalline form or in the non-crystalline, amorphous form or mixtures thereof. For optimum results, the beta content of the raw material should be less than 15% of the total Si 3 N 4 content.
In accordance with the present invention, the silicon nitride compositions must contain yttrium oxide and magnesium oxide as sintering aids in the range of 5 to 20 weight percent of the total, the balance being silicon nitride. The preferred range is from about 5 to about 12 percent. The weight ratio of yttrium oxide to magnesium oxide must be in the range from 1.0 to 1 to 7.0 to 1 for the starting powder mix. The preferred range is from about 1 to 1 to about 4 to 1.
The purity of the Si 3 N 4 raw material is also an important consideration. Impurities which may be present in the starting powders tend to concentrate in the intergranular phase of the densified article. Impurities may also find their way into the finished article during processing steps of a starting powder composition which has the desired initial high purity. The oxygen content of the silicon nitride raw material is usually present in the form of SiO 2 and must be taken into consideration for accurate control of the grain boundary phases. Other impurities such as carbon or free silicon must be controlled so as to compensate their effect on the intergranular phase of the finished article.
The silicon nitride compositions of the present invention are composed of silicon nitride grains surrounded by an intergranular phase consisting of SiO 2 , MgO, Y 2 O 3 , and a indeterminate amount of nitrogen. The usual form of this intergranular phase is a magnesium yttrium silicate glass, although crystalline phases can be produced by proper heat treatment. The composition of the intergranular phase of the present invention, excluding nitrogen, is preferably 10 to 60 weight percent SiO 2 , 20 to 70 weight percent Y 2 O 3 , and 5 to 45 weight percent MgO.
Small amounts of aluminum oxide, less than 1 weight percent of the total composition, can be tolerated as an impurity without a drastic change in performance. Inert materials such as tungsten carbide or titanium nitride should be present in amounts less than 5 and preferably less than 3 weight percent of the total composition.
Embodiments of the present invention can be seen in the following examples:
EXAMPLE 1
About 95 parts of silicon nitride powder containing 1.33 weight percent oxygen and composed of 90% alpha phase was mixed with 2.5 parts magnesium oxide and 2.5 parts yttrium oxide. The mixture was ball milled with 500 ml of naptha in a rubber lined mill using WC-Co grinding balls for 12 hours. The amount of tungsten pickup was less than one weight percent. The mixture was dried and charged into a graphite mold and hot pressed at 1750° C., 4,500 psi, for 60 minutes in an argon atmosphere. The density of the part was measured to be 3.23 g/cc and the Rockwell A hardness was measured to be 93.0 to 93.5. X-ray diffraction of the finished piece indicated the silicon nitride had completely transformed into the beta phase.
The compositions shown in Table I were prepared according to the method used in example 1. A.N.S.I. style SNG433 cutting tips were prepared from the hot pressed pieces. The cutting edges were chamfered 20° by 0.008" wide.
The cutting inserts were used to face mill a 2 inch diameter bar of nodular cast iron, 220 BHN. The milling cutter used was 6" in diameter with -5° axial rake and -5° radial rake. The lead angle was 15°. The machining conditions used were 1360 surface feet per minute cutting speed, 0.060" depth of cut, and a feed rate of 0.005 inches per revolution. Successive passes were taken on the cast iron and the cutting edges were examined for flank wear and chippage every eighth pass. Testing was terminated when the flank wear or chippage exceeded 0.015" depth as measured in a toolmakers microscope, or 48 passes. The data shown in Table II are the average results of a minimum of two tests.
Composition 1 is a typical prior art silicon nitride material while composition 2 is a commercial cutting tool. The commercial Y 2 O 3 containing cutting tool is an improvement over prior art MgO containing materials, but compositions of this invention show greatly improved performance over typical Si 3 N 4 --Y 2 O 3 compositions. Compositions 6 and 7, which are outside the scope of this invention, clearly show the importance of precise control of the grain boundary phase composition.
Compositions 17 and 18 have similar grain boundary compositions and had similar machining performance. Composition 18 was made with high oxygen content Si 3 N 4 powder while composition 17 was made with low oxygen content powder with added SiO 2 . The results indicate that the oxygen content of the starting raw material can be as high as 3.5 weight percent without greatly changing the performance.
TABLE I______________________________________ GRAIN BOUNDARY PHASE COMPOSITION (wt %).sup.1STARTING COMPOSITION SiO.sub.2.sup.2 MgO Y.sub.2 O.sub.3______________________________________1. Si.sub.3 N.sub.4 + 4 MgO 37.5 62.5 --2. Si.sub.3 N.sub.4 + 8 Y.sub.2 O.sub.3.sup.3 22 -- 883. Si.sub.3 N.sub.4 + 1.5 MgO + 5.5 Y.sub.2 O.sub.3 25 16 594. Si.sub.3 N.sub.4 + 2.5 MgO + 4.5 Y.sub.2 O.sub.3 25 27 485. Si.sub.3 N.sub.4 + 3.5 MgO + 3.5 Y.sub.2 O.sub.3 25 37.5 37.56. Si.sub.3 N.sub.4 + 4.5 MgO + 2.5 Y.sub.2 O.sub.3 25 48 277. Si.sub.3 N.sub.4 + 5.5 MgO + 1.5 Y.sub.2 O.sub.3 25 59 168. Si.sub.3 N.sub.4 + 1.0 MgO + 1.0 Y.sub.2 O.sub.3 55 22.5 22.59. Si.sub.3 N.sub. 4 + 2.5 MgO + 2.5 Y.sub.2 O.sub.3 32 34 3410. Si.sub.3 N.sub.4 + 4.5 MgO + 4.5 Y.sub.2 O.sub.3 20 40 4011. Si.sub.3 N.sub.4 + 6.0 MgO + 6.0 Y.sub.2 O.sub.3 16 42 4212. Si.sub.3 N.sub.4 + 8.0 MgO + 8.0 Y.sub.2 O.sub.3 12 44 4413. Si.sub.3 N.sub.4 + 10.0 MgO + 10.0 Y.sub.2 O.sub.3 10 45 4514. Si.sub.3 N.sub.4 + 2.5 MgO + 3.5 Y.sub.2 O.sub.3 28 30 4215. Si.sub.3 N.sub.4 + 1.5 MgO + 3.5 Y.sub.2 O.sub.3 32 20 4816. Si.sub.3 N.sub.4 + 0.5 MgO + 6.5 Y.sub.2 O.sub.3 25 5 7017. Si.sub.3 N.sub.4 + 3.5 MgO + 3.5 Y.sub.2 O.sub.3 40 30 30 + 2.5 SiO.sub.218. Si.sub.3 N.sub.4 + 3.5 MgO + 3.5 Y.sub.2 O.sub.3 45 27.5 27.5______________________________________ .sup.1 Neglecting nitrogen content. .sup.2 Based on an oxygen content of 1.33 wt. % of the Si.sub.3 N.sub.4. .sup.3 Commercial Tool contains 1-2 wt. % Al.sub.2 O.sub.3.
TABLE II______________________________________AVERAGE NUMBER OF PASSESCOMPOSITION TO FAILURE REMARKS______________________________________ 1 9 Chipping 2 24 Chipping 3 >48 Uniform Flank Wear 4 >48 Uniform Flank Wear 5 >48 Uniform Flank Wear 6 15 Fracture 7 5 Fracture 8 20 Chipping 9 39 Chipping10 45 Slight Chipping11 >48 Uniform Flank Wear12 >48 Uniform Flank Wear13 48 Slight Chipping14 >48 Uniform Flank Wear15 >48 Uniform Flank Wear16 48 Slight Chipping17 48 Slight Chipping18 48 Slight Chipping______________________________________
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A silicon nitride cutting tool primarily for cutting cast iron comprises a granular phase consisting essentially of silicon nitride and an intergranular amorphous phase consisting essentially of magnesium oxide, yttrium oxide and silicon oxide wherein the components are present in specified amounts and ratios.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a system and method for reconstructing an anterior cruciate ligament (ACL) and more particularly to a method and gauge for dimensioning a femur tunnel in such a reconstruction.
[0003] 2. Description of the Related Art
[0004] An injured ACL is commonly reconstructed by placing a replacement graft through tunnels prepared in a patient's tibia and femur. In one type of such procedure described in U.S. Pat. No. 5,306,301, the contents of which are incorporated herein by reference, a tunnel is prepared in the femur from a position at or near the patellar surface up through a portion of the femur and exiting through the side of the femur at a superior location. A graft is looped over a loop attached to an elongated bar. The bar is able to pass in one direction up through the tunnel and then out adjacent the superior end of the tunnel. The bar is reoriented such that it will not pass back through the tunnel and is positioned against the femur with the loop and graft hanging down into the tunnel therefrom. The tunnel has sufficient diameter at its inferior portion to accommodate the graft. The tunnel is preferably made narrower at the superior portion, which carries only the loop and not the graft, to minimize bone removal. For convenience, the inferior portion of the tunnel can be termed the socket. Determining a proper depth of the socket quickly, accurately and easily is desired.
SUMMARY OF THE INVENTION
[0005] An instrument according to the present invention provides for determining a depth of a bone tunnel in an ACL reconstruction. The instrument comprises a measuring pin having an elongated body having a first end and a first indicia spaced apart from the first end. A first tube co-axially receives the first end of the measuring pin body, the first tube having in internal diameter sized to accommodate the measuring pin body first end, an open first end and a second end. A second tube at the first tube second end has an internal diameter larger than the first tube internal diameter and an first end connected to the first tube second end. A measuring block is disposed at least partially within the second tube and has an abutment and a socket depth scale indicia thereon. A first indicator on the second tube is oriented relative to the socket depth scale indicia being oriented such that when the measuring pin body first end abuts the measuring block abutment the alignment of the indicator and the socket depth scale indicia provides a reading indicative of a desirable depth of the bone tunnel.
[0006] Preferably, the measuring block is biased toward the first tube. Also preferably, the first indicator is the second tube second end. Preferably, a loop size indicia is provided thereon.
[0007] Preferably, the reading on the socket depth scale indicia represents the distance between the first indicia and the first tube first end minus a loop size indicated by the loop size indicia plus a predetermined flip length. The flip length is a distance beyond the femur necessary to reorient an elongated bar carrying a loop from which the graft is suspended into the bone tunnel from an orientation which allows it to pass through the bone tunnel into a sideways orientation which prevents its passage back into the bone tunnel.
[0008] Preferably, a second loop size indicia indicating a different value than the loop size indicia and a second socket depth indicia associated therewith. Accordingly, the reading on the socket depth scale indicia represents the distance between the first indicia and the first tube first end minus a loop size indicated by the loop size indicia plus a predetermined flip length and the reading on the second socket depth scale indicia represents the distance between the first indicia and the first tube first end minus a loop size indicated by the second loop size indicia plus the predetermined flip length. Multiple loop size indicia and associated socket depth indicia can be provided to provide socket depth readings for different loop sizes with a single instrument.
[0009] Preferably, the second tube has a graft implantation depth indicia thereon and wherein the measuring block has an associated second indicator associated therewith to provide a reading of a depth of implantation of a graft into the bone tunnel. In such case the reading on the implantation depth scale indicia preferably represents the distance between first indicia and the first tube first end minus the loop size indicated by the loop size indicia.
[0010] A method according to the present invention provides for measuring a depth of a socket portion of a bone tunnel in an ACL reconstruction. The method comprises the steps of: creating a pilot hole through a femur so that the pilot hole has a first end at a condylar notch surface of the femur and a second end at a superior portion of the femur, the pilot hole being oriented along a path desired for a replacement ligament in the femur; positioning a measuring pin so that a first indicia on the measuring pin is located at the pilot hole first end and a second end of the measuring pin extends out of the pilot hole second end; placing a first tube over the measuring pin such that a portion of the measuring pin is coaxially received therein and a first end of the first tube abuts the femur at the pilot hole second end; abutting the second end of the measuring pin against an abutment on a measuring block having a distance scale indicia thereon, the measuring block having a lateral dimension larger than a largest lateral dimension of the measuring pin; and reading a desired depth for the socket portion of the bone tunnel from the distance scale indicia, the socket portion extending from the pilot hole first end along the path defined by the pilot hole.
[0011] Preferably, the pilot hole is created with the measuring pin. Also preferably, an indicator is associated with the first tube, and the indicator provides the reading on the distance scale.
[0012] Preferably, the desired depth read on the distance scale correlates to a distance separating the first tube first end and the first indicia on the measuring pin, more specifically the desired depth represents the distance separating the first tube first end and the first indicia on the measuring pin minus a predetermined loop size plus a predetermined flip length. Preferably, the predetermined loop size is indicated adjacent the distance scale.
[0013] The method preferably further comprises the step of drilling the socket portion into the femur to the indicated depth from the condylar notch along the path. The method preferably further comprises the steps of: suspending the graft over a loop of the predetermined loop size, the loop being connected to an elongated bar; passing the elongated bar lengthwise through the bone tunnel and positioning the bar against the superior portion of the femur in a sideways orientation to prevent its passage back into the bone tunnel leaving the loop depending down into the socket portion and the graft suspended at least partially in the socket portion from the loop. The predetermined flip length is a distance beyond the femur sufficient to manipulate the bar from its lengthwise orientation into its sideways orientation after is has been passed through the tunnel and with the loop depending back into the tunnel.
[0014] Preferably, a further reading is made of an implantation depth length of the implant in the socket portion from a socket depth indicia associated with the first tube, the implantation depth representing the distance separating the first tube first end and the first indicia on the measuring pin minus the predetermined loop size.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In what follows, preferred embodiments of the invention are explained in more detail with reference to the drawings, in which:
[0016] FIG. 1 is a side elevation view of a first embodiment of a beath pin according to the present invention;
[0017] FIG. 1A is a side elevation view of a second embodiment of a beath pin according to the present invention;
[0018] FIG. 1B is a side elevation view of a further embodiment of a beath pin according to the present invention;
[0019] FIG. 2 is a side elevation view of a portion of a depth gauge according to the present invention;
[0020] FIG. 3 is a side elevation view in cut-away of the depth gauge of FIG. 2 ;
[0021] FIG. 3A is a perspective view in partial phantom of a second embodiment of a depth gauge according to the present invention;
[0022] FIG. 3B is a side elevation view of a further embodiment of a depth gauge according to the present invention;
[0023] FIG. 4 is a perspective view of a graft construct for use in the procedure according to the present invention;
[0024] FIG. 5 is a side elevation view in cut-away of a knee having an ACL reconstruction according to the present invention;
[0025] FIG. 6 is a front elevation view of a femur of the knee of FIG. 5 showing the creation of a pilot hole using the beath pin of FIG. 1 ;
[0026] FIG. 7 is a front elevation view of a femur of the knee of FIG. 5 showing the beath pin of FIG. 1 inserted to a pre-determined depth;
[0027] FIG. 8 is a perspective view of the depth gauge of FIGS. 2 and 3 being placed onto the beath pin;
[0028] FIG. 9 is a perspective view of the depth gauge and beath pin of FIG. 8 with an end of the depth gauge engaging a surface of the femur;
[0029] FIG. 10 is a side elevation view of the depth gauge of FIG. 8 showing the indicated reading for socket depth;
[0030] FIG. 11 is a front elevation view of the femur of the knee of FIG. 5 showing the socket being drilled;
[0031] FIG. 12 is a front elevation view of the femur of the knee of FIG. 5 showing the passing channel being drilled; and
[0032] FIG. 13 is a front elevation view of the femur of the knee of FIG. 5 showing the graft construct being passed.
DETAILED DESCRIPTION
[0033] FIGS. 1 to 3 illustrate primary components of the present invention. FIG. 1 depicts a beath pin 10 having an elongated body 12 , sharp distal tip 14 , optional drill flutes 16 adjacent the distal tip 14 and a laser etched depth indicia 18 located about 15 cm from the distal tip 14 . FIG. 1A depicts an alternative beath pin 20 having an elongated body 22 , sharp distal tip 24 , drill flutes 26 adjacent the distal tip 24 and an annular flange 28 in place of the laser etched depth indicia 18 of the beath pin 10 . The pins 10 or 20 will be passed into a femur (not shown in FIGS. 1 to 3 , to either the indicia 18 or the flange 28 and the flange provides a tactile feedback to a surgeon that the correct depth of passage into the femur has occurred. FIG. 1B depicts an alternative beath pin 27 having a reverse annular flange 29 that provides a visual feedback that the correct depth of passage into the femur has occurred. The reverse flange 29 also allows the beath pin 27 to be removed by pulling it through the passage forwardly and out of the femur.
[0034] FIGS. 2 and 3 illustrate a depth gauge 30 for measuring and sizing the tunnel in the femur. The gauge comprises an elongated cylindrical first tube 32 sized to accommodate the beath pin 10 , the first tube 32 has a first end 34 and a second end 36 attached to a larger second tube 38 . The second tube 38 has a first end 40 attached to the first tube 32 , a free second end 42 . The second end 36 may be releasably attached via threads, snaps, bayonet fittings, or other means to the second tube 38 to allow the tube 32 to be disposable. A measuring block 44 travels within the second tube 38 and is preferably biased toward the first end 40 by a tension spring 46 . A first end 48 of the measuring block 44 acts as an abutment against the tip 14 of the beath pin 10 . It can be slightly countersunk for more positive engagement. A depth indicia scale 50 is provided on the measuring block and a loop size indicia 52 is provided toward a second end 54 of the measuring block 44 .
[0035] The beath pins 10 , 20 and 27 are preferably of small diameter, such as 2.4 mm. Markings thereon would be quite difficult to see due to its small size and could become obscured by body tissue. The measuring block 44 has an increased size making reading the indicia scale 50 easy. Preferably, the measuring block 44 has a width of at least 8 mm. The present arrangement also covers the sharp distal tip 14 of the beath pin 10 to enhance safety.
[0036] FIGS. 3A and B depict an alternative embodiments in which similar parts are identified with similar numerals with the subscripts “a” and “b” respectively. In FIG. 3A , a measuring block 44 a has a projection 45 extending into the second tube 38 a and it is against this projection 45 which the beath pin tip 14 abuts. This provides for a shorter and thus safer beath pin. In FIG. 3B a second tube 38 b is provided with an additional marking scale 51 on a window 53 through which can be seen an indicator 55 on a measuring block 44 b. The marking scale 51 indicates the length of the graft disposed within the femur as will be discussed ahead. Additionally, the measuring block 44 b and second tube 38 b can be provided with multiple faces disposed circumferentially thereabout, each with its own corresponding indicia scale 50 b, additional marking scale 51 and loop size indicia 52 b . For instance, one face could be arranged to work with a 20 mm loop size, a second face with a 25 mm loop size etc. with the loop size indicia 52 b, indicia scale 50 b and additional scale 51 arranged accordingly.
[0037] FIG. 4 illustrates a graft construct 60 comprising an elongated bar 62 having a thick suture loop 64 through a pair of central openings 66 along with first and second guiding sutures 68 and 70 through first and second outside holes 72 and 74 respectively. A replacement graft 76 is looped over the loop 64 . FIG. 5 illustrates the graft construct 60 in place in a patient's leg 78 . A tunnel 80 in the leg's femur 82 comprises a larger diameter inferior portion or socket 84 sized to accommodate the graft 76 and a smaller diameter superior portion or passing channel 86 sized to accept the bar 62 in a lengthwise orientation. The bar 62 sits against the femur 82 in a sideways orientation with the loop 64 depending down through the passing channel 86 and into the socket in which is placed the graft 76 . An opposite end of the graft 76 is placed into a tibial tunnel 88 in the leg's tibia 90 and held in place with an anchor 92 such as the INTRAFIX® anchor available from DePuy Mitek Inc. of Raynham, Mass.
[0038] FIGS. 6 to 13 illustrate measurement and creation of the tunnel 80 . First a beath pin 10 is drilled in the desired orientation through the femur 82 creating a pilot hole 94 therethrough. The pin 10 is then advanced until the laser mark 18 is flush with the surface femur 82 (See FIGS. 6 and 7 ). An appropriate sized gauge 30 is selected based upon the length of the loop 64 , with that size being printed 52 on the gauge 30 . Alternatively, if the gauge 30 has multiple faces with indicias 50 etc. as heretofore described the appropriate loop size face is oriented toward the surgeon. The first tube 32 of the gauge 30 is passed over the beath pin 10 and advanced until its first end 34 abuts the femur (See FIGS. 8 and 9 ). The puts the beath pin through the femur 82 along the path (the pilot hole 94 ) which the soon to be drilled tunnel 80 will follow with the laser mark 18 at an inferior end 96 of the pilot hole 94 at a condylar notch surface 98 of the femur 82 and with the gauge first tube first end 34 at an opposite superior end 100 of the pilot hole 94 .
[0039] The distal tip 14 of the pin 10 abuts the measuring block first end 48 and pushes the measuring block 44 out of the second tube 38 against the resistance of the spring 46 and the indicia scale 50 can be read at the second tube second end 42 (see FIGS. 3 and 10 ). It returns the desired depth of the socket 84 from the condylar notch surface. A cannulated drill 102 of appropriate diameter for the socket 84 and having drilling depth indicia 104 thereon is passed over the beath pin 10 and the socket is drilled to the appropriate depth as indicated by the indicia scale 50 (see FIG. 11 ). Then a separate, smaller cannulated drill 106 is passed over the pin 10 and the passing channel 86 is drilled through the femur 82 (see FIG. 12 ). The graft construct 60 is then pulled up through the tunnel 80 with the bar 62 in a lengthwise orientation via the first suture 68 and then the bar 62 is manipulated into a sideways orientation via the second suture 70 and placed into abutment against the femur 82 .
[0040] The depth gauge 30 provides the surgeon with the necessary information to drill the socket 84 for a given loop size. The length of the tunnel 80 is determined by the anatomy of the femur 82 and the path of the tunnel 80 therethrough. The gauge 30 measures this length by the spacing of the laser mark 18 and the gauge first tube first end 34 . This spacing is then translated into an appropriate socket 84 depth by the size and orientation of parts of the gauge 30 . The gauge 30 determines this depth by subtracting the loop length from the total length and then adding a length sufficient to allow the bar 62 to be pulled free of the femur and flip its orientation, about 8 to 10 mm. The graft length in the socket 84 shown by the scale 51 represents the socket 84 depth minus the flipping length. Rather than the surgeon having to perform calculations the gauge scales are oriented to read out the proper socket depth and graft length in the tunnel for a given loop size.
[0041] Thus, while there have been shown, described, and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions, substitutions, and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit and scope of the invention. For example, it is expressly intended that all combinations of those elements and/or steps that perform substantially the same function, in substantially the same way, to achieve the same results be within the scope of the invention. Substitutions of elements from one described embodiment to another are also fully intended and contemplated. It is also to be understood that the drawings are not necessarily drawn to scale, but that they are merely conceptual in nature. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
[0042] Every issued patent, pending patent application, publication, journal article, book or any other reference cited herein is each incorporated by reference in their entirety.
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A depth gauge and method provide for accurate measurement of a socket portion of a bone tunnel in an ACL reconstruction.
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BACKGROUND OF THE INVENTION
[0001] A combination of static and dynamic shielding is disclosed that prevents cross contamination in a multi-target long throw remote plasma based deposition process. In particular, special static shields with innovative features to allow rotate/index of sputter targets at extreme target tilt angle ranges are disclosed.
[0002] Long-throw remote plasma based deposition processes have long been employed for plasma processing of substrates (e.g., wafers, flat panel displays, portable device displays, etc.). In a long-throw plasma based deposition process, a plasma source, such as an ion source, is positioned some distance away from the target while bombarding the target with ions. The ions from the plasma source sputter material off the target, which causes the sputtered material to be deposited on the surface of a substrate.
[0003] To elaborate, the term “long throw” refers to the fact that the target is located typically (but not always necessarily) at least one wafer diameter away from the wafer. Long-throw plasma based deposition is particularly suitable for applications where extremely tight uniformities are required across the wafer, or when excellent step coverage of features are desired. Multi-target long-throw plasma based deposition employs multiple targets whereby a specific target can be moved or rotated in place for sputtering when called for by the recipe.
[0004] FIG. 1 shows a prior art arrangement for performing long throw deposition wherein the target angle can be tilted to improve deposition uniformity and film properties such as stress hardness, electrical conductivity, etc. Referring now to FIG. 1 , there is shown a port 102 representing the opening into which the opening of a plasma source may be fitted. The plasma source may generate plasma from, for example, RF energy via an inductive coil. The plasma source is omitted in FIG. 1 to simplify discussion since the plasma source itself is not a central feature of the present invention.
[0005] The ions from the plasma travel toward target 104 to sputter material off the surface of target 104 for deposition on a wafer.
[0006] In the example of FIG. 1 , the shutter is shown open; and the wafer may be mounted to tilt-and-rotate fixture 110 such that when plasma is generated in the plasma source and ions from the plasma sputter material off the surface of target 104 , the sputtered material would cause deposition to occur on the surface of the wafer. Target 104 is tiltable and rotatable in order to facilitate tuning of the deposition process and parameters. For example, the thickness uniformity of the film on the wafer and/or the etch rate from the target may be changed, and/or film stress may be changed, by tilting the target at an appropriate angle. As another example; the etch rate may change depending on the tilt angle of the target.
[0007] In the prior art, there exist multi-target systems wherein multiple targets formed of the same or different materials may be mounted on a rotatable turret. The rotatable targets form what is commonly known as a target assembly turret with different targets being set at different tilt angles. The target assembly turret is rotatable to rotate (or index) the target into the appropriate position for use. Generally speaking, only one target is exposed to the ions from the plasma at any given time for sputtering purposes while the other targets are shielded from the plasma.
[0008] As mentioned earlier, different targets may be formed of different materials. As such, it is important to keep the cross-contamination of target materials among different targets to a minimum during deposition. Cross contamination may occur when a target is rotated or indexed into position for sputtering and inadequate shielding allows material sputtered from that target to be splattered or deposited onto a neighboring target of the target assembly turret. Cross contamination is highly undesirable since a target contaminated with materials from its neighbor target may cause unintended material deposition on the substrate surface, resulting in defective devices on the wafer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
[0010] FIG. 1 shows a prior art arrangement for performing long throw deposition
[0011] FIG. 2 shows an example target assembly turret having six targets to facilitate discussion.
[0012] FIG. 3 shows, in accordance with an embodiment of the invention, the static and dynamic shields.
[0013] FIG. 4 shows, in accordance with an embodiment of the invention, relevant portions of the deposition system including the innovative static and dynamic shields.
DETAILED DESCRIPTION OF EMBODIMENTS
[0014] The present invention will now be described in detail with reference to a few embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, 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 steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention.
[0015] The present invention relates to improved shielding arrangements, including a combination of dynamic and static shields, for simultaneously minimizing the size of the chamber and improving cross contamination avoidance. In one or more embodiments, the static shield pieces are designed such that when a target is rotated (or indexed—the terms being synonymous herein) into position for sputtering, two especially designed dynamic shields are aligned with the two especially designed static shield pieces, thereby forming a tight seal to prevent cross contamination to other targets of the target assembly turret during sputtering.
[0016] The two especially designed static shield pieces are, in one or more embodiments of the invention, provided with optional cutouts to accommodate the extreme tilt angles of the target during indexing. By providing the optional cutouts, it is possible to index the target even when the target is tilted beyond the coverage of the dynamic shield piece. In this manner, the dynamic shield piece may be made as small as possible to minimize the size of the target cover housing while preventing damage to the target during indexing if the target happens to be tilted at an extreme angle while being indexed. In one or more embodiments, the size and location of each optional cutout is such that cross contamination from target to target of the target assembly turret is substantially minimized.
[0017] The features and advantages of the invention may be better understood with reference to the figures and discussions that follow. FIG. 2 shows an example target assembly turret having six targets, of which four targets 202 , 204 , 206 and 208 are shown. Each of the six targets may be formed of a similar material or of different materials. Further, each target may be pre-tilted or dynamically tilted during use at a specific angle in the target assembly turret.
[0018] During deposition, only one target (i.e., the target currently employed for sputter deposition purpose) is positioned facing the source and the wafer. The other targets are shielded, at least partially, by the dynamic shield pieces that exist between the neighboring targets. As the terms are employed herein, dynamic shield pieces refer to shield structures that rotate or index along with the targets when the targets are rotated or indexed. In contrast, static shield pieces refer to shield structures that are stationary even when the targets are rotated.
[0019] For example, neighboring targets 202 and 206 are shielded from cross contamination that may originate from neighboring target 204 during deposition by the use of dynamic shields 210 and 212 . As shown in the example of FIG. 2 , dynamic shields 210 and 212 are positioned vertically relative to the rotational plane of the target turret assembly to reduce splattering.
[0020] FIG. 3 shows, in accordance with an embodiment of the invention, static shields 302 and 304 , which are integrated with the target cover housing such that static shields 302 and 304 remain stationary when the target assembly turret with its targets and dynamic shields rotate to index individual targets into position for sputtering. In the example of FIG. 3 , static shield 302 includes a plurality of flanges 310 A, 310 B and 310 C to facilitate fastening or attaching static shield 302 to the surface(s) of the target cover housing. Although three flanges are shown, a greater or fewer numbers of flanges may be employed. Any suitable and/or conventional method of attachment of the flanges to the target cover housing may be employed. The goal is to attach the static shields to the target cover housing (an example of which is shown in FIG. 4 ) and the exact method of attachment is not central to embodiments of the invention herein.
[0021] Each of static shields 302 further includes an optional cutout 320 , which is shaped and dimensioned to allow the target assembly turret to rotate even when the target that is recently employed for sputter deposition is tilted at an extreme angle prior to or during indexing. When such target is tilted at an extreme angle, it is possible that the bottom part of that target (such as target 204 of FIG. 2 ) juts or protrudes out beyond the plane formed by edge 322 of dynamic shield 210 and edge 324 of dynamic shield 212 . If optional cutouts 320 and 330 were not provided in static shields 302 and 304 respectively, the dynamic shields 210 and 212 would have to be made much larger to prevent damage to the extreme tilt target 204 when the target assembly turret rotates to index extreme tilt target 204 away from the operational position and to index another target into the operational position for sputtering.
[0022] In one or more embodiments, the size of each optional cutout is dimensioned such that it provides just sufficient clearance for target assembly turret rotation, even when the recently-employed target is at an extreme tilt angle, without presenting an undue opening that may increase the amount of cross contamination from one target to the next target. Generally speaking, this involves cutting a small section from the optional cutout that is just enough to allow a target tilted at its extreme tilt angle to pass through. By using innovative static shields 302 and 304 with optional cutouts 320 and 330 in the static shields, dynamic shields 210 and 212 may be kept smaller, which helps reduce the size of the target cover housing. Advantageously, this reduction in the target cover housing size allows the surface of the target cover housing to be brought closer to the targets to provide a greater clearance for wafer insertion.
[0023] As can be seen in FIG. 3 , the static shields are also disposed vertically with respect to the rotational plane of the target assembly turret such that when target is indexed/rotated into position for sputtering, its two dynamic shields are aligned with the two static shields to form a larger shielding area, thereby minimizing cross contamination from target to target during the sputter deposition operation.
[0024] FIG. 4 shows, in accordance with an embodiment of the invention, relevant portions of the target assembly turret 402 , source opening 404 , and tilt-and-rotate fixture 406 . The target cover housing is shown by reference number 410 and comprises surfaces 410 A, 410 B, 410 C and 410 D. This particular design of the target cover housing is only an example and other designs with a greater number or fewer number of surfaces are also possible. The static shields, which are shown as static shields 302 and 304 (see FIG. 3 ), may be attached to one or more of surfaces 410 B, 410 C or 410 D of the example target cover housing 410 and may protrude toward the target turret assembly as shown.
[0025] In the drawing of FIG. 4 , portions of static shield 302 and static shield 304 are shown.
[0026] Generally speaking, it is desirable to move surface 410 C as far away from tilt-and-rotate fixture 406 as possible to facilitate wafer loading and unloading. However, when surface 410 , for example, is brought closer to the target assembly turret, a large dynamic shield may Strike the inner surface 410 C when the target assembly turret rotates and indexes its targets from position to position. By providing the static shields with optional cutouts, such as static shields 302 and 304 , the dynamic shields (such as dynamic shields 210 and 212 ) may remain smaller such that when the target assembly turret rotates and dynamic shields 210 and 212 sweep rotationally, dynamic shields 210 and 212 do not impact or strike the inner surface of surfaces 410 C, 410 D or the opening in surface 410 C and 410 D.
[0027] As mentioned, optional cutouts (see 320 and 330 of FIG. 3 ) are provided to permit dynamic shields 210 and 212 to be smaller. If these optional cutouts (see reference numbers 320 and 330 of FIG. 3 ) were not provided, dynamic shields 210 and 212 would have to be made larger in order to prevent damage to extreme-tilt target 204 during indexing/rotation. By providing optional cutouts 320 and 330 , the dynamic shields 210 and 212 may be made smaller, thereby allowing surfaces 410 B, 410 D and 410 C to be brought closer to the target assembly turret and/or further away from tilt-and-rotate fixture 406 to facilitate wafer mounting and removal.
[0028] As can be appreciated from the foregoing, embodiments of the invention advantageously minimize cross contamination from target to target in a multi-target long throw deposition process. By using a combination of static and dynamic shields with optional cutouts, it is possible to permit the target assembly turret to freely rotate while keeping the target cover housing small and disposed further away from the tilt-and-rotate fixture and/or the plasma source to facilitate wafer mounting/removal.
[0029] While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents, which fall within the scope of this invention. For example, although the optional cutouts are shown with both static shield pieces, it is possible to further reduce the risk of cross-contamination by providing the optional cutout with only one of the two static shields if rotation is only in one direction (e.g., only clockwise or counter-clockwise) and there is no danger of target damage due to an extreme tilt angle when rotating past one of the static shields (which makes it possible to eliminate the optional cutout for that one static shield). This is the case if, for example, the targets are always stowed when not in use and rotating a stowed target into position for sputtering would not involve the risk of damaging that target since that target would not be in an extreme tilt position. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present invention. Although various examples are provided herein, it is intended that these examples be illustrative and not limiting with respect to the invention. If the term “set” is employed herein, such term is intended to have its commonly understood mathematical meaning to cover zero, one, or more than one member.
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A multi-target deposition arrangement comprising of a target assembly turret configured to be rotatable is provided. The arrangement also includes a plurality of targets mounted on the target assembly turret, wherein a first target is positioned in an operational position, which is facing a substrate during sputtering. The arrangement further includes a shield arrangement that includes at least a set of static shields and a set of dynamic shields. The set of static shields is attached to the target assembly turret. The set of dynamic shields is aligned with the set of static shields when the first target is rotated into the operational position for sputtering, wherein the shield arrangement prevents cross contamination to other targets when the sputtering is occurring to the first target.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to radiation therapy of proliferative disease as required adjuvant care following surgical resection of tumors or other pathological conditions. More particularly, it pertains to the intraoperative application of therapeutic radiation emitted from radiation sources positioned within the resection cavity created by surgical resection. Discussion herein is largely directed to radiotherapy following at least partial resection of breast tumors, but it is to be understood that the apparatus and methods may be applied to different anatomical sites.
[0002] It has been demonstrated in many areas of surgical oncology that adjuvant radiation treatment following tumor resection reduces the likelihood of recurrence of cancer or other proliferative disease. The likelihood of infiltrative disease decreases with distance from a primary site in a tissue with confirmed disease. It has also been shown that brachytherapy delivered from within the resection cavity is as effective as external beam therapy, reduces exposure of normal tissue to inadvertent radiation exposure, and furthermore, that quality of life is superior after brachytherapy compared to that following external beam therapy. It is therefore desirable that brachytherapy or brachytherapy-like techniques be made available to as great a population of patients as possible.
[0003] Many radiotherapists prefer to deliver radiotherapy in fractions spaced in time (over a period of several days or even weeks) using intracavitary brachytherapy techniques to take advantage of the fact that normal cells recover from radiation exposure in a shorter period of time than diseased cells. Other radiotherapists have found intraoperative radiation therapy (IORT, radiotherapy delivered during the same operative procedure as the tumor resection) to be equally if not more effective in many circumstances, and may offer the opportunity for simultaneous reconstructive surgery. This invention pertains to IORT, or delivery of other single-treatment radiotherapy wherein a complete treatment or prescription is delivered from the resection cavity in one dose during a conventional open surgical procedure. It has also been demonstrated that radiation intensity diminishes with distance from the radiation source. Radiotherapists fairly universally have therefore found that it is generally desirable to spatially separate the radiation source from the tissues being treated. This reduces the likelihood of exposing normal tissue to harmful levels of radiation, particularly that tissue nearest the radiation source, while still delivering the prescribed radiation to the prescribed depth. In a situation where the resection cavity is substantially centered on the site of the tumor, the prescription depth is the depth in tissue outside the resection cavity where the likelihood of undiagnosed disease is highest and where adjuvant radiation treatment is warranted. The target tissue is the tissue to which this prophylactic radiotherapy is directed, generally lying outside the resection cavity, but within the bounds of the prescription depth. Where the cavity (and hence the resected tissue specimen) is eccentric about the tumor location, that portion of the cavity farthest from the tumor may require less radiation prescription depth than tissues near the resected tumor location.
[0004] To create this spatial separation in traditional intracavitary brachytherapy, an applicator, usually comprising a balloon, is positioned and inflated within the resection cavity. For the same reasons as above, it is also desirable to create spatial separation preparatory to IORT treatment within an open surgical cavity. At present, however, there are no applicators, analogous to the balloon applicators described above, for use with IORT methods in open surgical fields. A purpose of this invention is to fill that need.
[0005] Traditional brachytherapy sources are isotopic seeds, often of iridium 192 positioned on wires, which are manipulated within applicator source guides and balloons to deliver the prescribed treatment to the target tissue surrounding the balloon and resection cavity. Emissions from iridium and other common medical isotopes usually have high-energy components which can penetrate deeply into tissue. They also emit continuously, and thus can only be used in special, heavily-shielded rooms. In addition, concerns for the safety of personnel require isolation of the patient during treatment, shielded storage at all other times, and automated handling between the storage chamber and the applicator when in the patient. In total, the capital expense required for such facilities dictates that treatment centers be located in urban areas so as to serve sizeable patient populations. This can result in under serving rural patients who cannot repeatedly travel to urban treatment centers for a course of prolonged radiation treatment. Furthermore, the need for patient isolation is inconvenient for therapists, not to mention daunting for the patients under treatment. With such brachytherapy, it is clear that any improvements to the total duration of treatment, cost, source handling and shielding difficulties, patient fear factors and inconvenience would be welcome.
[0006] Recently, miniature electronic x-ray tubes have provided a preferable alternative to use of isotopes. Such tubes do not emit continuously, they only emit when powered in a manner causing emission and they can be turned on and off, or if desired, modulated such that their penetration depth can be controlled (by control of acceleration voltage) and their dose intensity can be controlled (by filament current) as well. One reference describing the principles and construction of such tubes is Atoms, Radiation and Radiation Protection, Second Edition, John E. Turner, Ph.D., CHP, 1995, John Wiley & Sons, Section 2.10. Electronic brachytherapy sources generally require cooling and are usually contained in a fixed position within a catheter designed for the purpose, but otherwise are more versatile and convenient to use than isotopes, and can be engineered to accommodate a wide variety of dosimetric prescription detail. In addition miniature x-ray tubes can be designed to emit substantially isotropically, or directed to emit only through a predetermined solid angle, permitting more detailed treatment plans. Isotope radiation cannot be controlled in this manner. Furthermore, the x-ray energy spectrum in ranges suitable for brachytherapy or IORT eliminates the need for heavily shielded structures, or “bunkers”, and also permits the therapist to be in the room with the patient during therapy. Therapy can proceed in almost any medical facility, urban, rural or even mobile,and therefore, with miniature x-ray tubes, a greater population of patients can be treated, and the costs of therapy are greatly reduced. It is clear that electronic brachytherapy sources have already contributed significantly to making such therapy more readily available and cost effective than other methods. Treatment duration can still be improved, however, and IORT is a procedure directed to this end.
[0007] Tumor resection is usually carried out by open surgical technique where the surgeon proceeds directly through skin and tissue overlying the tumor, or at the surgeon's discretion, from a nearby point which may provide more pleasing cosmesis. The incision must accommodate tumor resection including excision of additional tissue around the tumor, the margins of which are believed to be disease free. Often, efforts are made to provide markers which help orient the tissue with respect to the cavity from which it was excised, and which provide a basis the pathologist and surgeon can use to communicate with respect to the precise location of the tumor within the specimen (thus the cavity) and/or the location of further disease at the margins. Once analyzed, and if necessary, further tissue is removed until the margins are “clear”, or free of apparent disease. In some modern institutions, this pathologic assessment is performed while the patient is still anaesthetized and on the operating table. Once the margins are determined to be free of disease, if IORT is the radiotherapy of choice, it is then administered.
[0008] Because the extent of the disease is uncertain at the outset of surgery, the incremental nature of the resection procedure in response to pathological findings may result in a cavity, the boundaries of which are eccentric with respect to tumor, and some margins which are relatively farther removed from the original tumor than others, and thus less likely to be infiltrated with disease. In such a circumstance, the prescription dose can be specified for delivery to an imaginary surface defined in relation the tumor location without reference to the cavity boundaries. It is an object of this invention to accommodate such eccentricity so that tissues lying farthest from the tumor receive a lower dose than those lying near the tumor site, and to facilitate preparation of such a treatment plan.
[0009] Other objectives of the invention will become apparent from the following summary, drawings and description.
SUMMARY OF THE INVENTION
[0010] This invention is intended particularly for the breast and comprises a rigid cup of predetermined shape, the sides of which are transparent to radiation and visible light, and the bottom of which is optionally attenuating in order to shield the underlying tissues and organs from harmful radiation. The cup is placed into the cavity, bottom first, and advanced until it reaches the bottom of the cavity. The cup is configured so as to substantially fill and shape the cavity. If desired, the cup can be sutured near its base to secure it to the bottom of the cavity. After being so placed, the conformance of the cavity tissue to the cup can be visually ascertained, and if necessary adjusted appropriately to eliminate voids or pockets of air or seroma. Alternatively, the surrounding tissue can be urged into conformance with the sides of the cup and held in place by conventional tapes and/or sutures, by selecting a differently shaped rigid cup, or by other methods including provision of a matrix on the outside of the cup for application of suction to draw breast tissue into conformance with the cup and so retain it during radiotherapy.
[0011] The invention further comprises a lid to cover the cup and a connection with a gasket or other conventional features proximate to the cup lip to create a fluid tight seal between the two elements. Near or at the periphery of the lid is a radiation attenuating skirt extending distally into the cup or just outside the cup (with securement threads for engaging the cup) to shield the skin and near-skin tissue gathered around the cup from radiation. If desired, the entire lid (or lid assembly if comprised of multiple elements) can be attenuating to protect those nearby during radiotherapy delivery. Extending through the lid is a tubular source guide which is radiation transparent and reaches sufficiently into the cup such that a radiation source can deliver as therapeutic dose. In one embodiment, the source can be manipulated within the guide (such positioning herein referred to as along the “Z” axis of the applicator or cavity) to effectively deliver the prescribed radiation. The distal end of the source guide is closed. Proximally, the guide extends outward of the lid to an open end where a source and catheter can be inserted. If source manipulation is desired, the proximal end of the source guide further comprises a flexible extension which can be secured to the source manipulator located outside the patient in order to provide a fixed reference distance between the outside manipulation apparatus to the patient and applicator. Such a flexible connection can accommodate patient motion, for example motion due to respiration, without introducing error in source positioning.
[0012] In simplest form, the cup is circular and the source guide is normal to the lid and located centrally to position the source equidistant from the sides of the cup in order for a substantially isotropic source to produce a laterally uniform isodose pattern. Other lid shapes and source guide positioning can be used to accommodate irregular cavity shapes and/or non-uniform prescription situations, and even source guide positions which are varied during the radiotherapy procedure. If the source position is to be varied laterally in the X and/or Y directions, the surface of the lid can comprise a membrane to which the source guide is secured and sealed, and which can accommodate the desired changes in position, X/Y or angular. Conventional servo-systems can provide such manipulation in response to computer commands, and with source positioning within the source guide along the Z axis, can position the source at any location within the cup.
[0013] Delivery of radiotherapy using such a system is preceded by a treatment planning procedure in which the anatomy and applicator apparatus may be imaged using conventional methods, usually either x-ray or CT, but since the cup is transparent and its shape is known, direct visualization may be adequate to check for tissue conformance to the cup such that the tissue can be gathered more effectively around the cup, and to identify the presence of pockets of air or seroma between the cup and tissue. Once the geometrical relationships are confirmed, the desired therapy can be planned and the source position(s) and/or manipulation determined. Ultimately, control parameters for the apparatus are programmed to produce the plan for use during treatment. Prior to treatment, and if desired before imaging and planning, the volume within the cup and lid is filled with an attenuating medium, preferably saline, and air from within the volume is vented if necessary. Next, a radiation shield or shields, perhaps with a hole to accommodate exit of the source guide, are draped on the patient around the applicator apparatus as necessary to protect those nearby during treatment. (See U.S. patent application Ser. No. 11/323,331.) The source is then inserted into the applicator, connected to the positioning control apparatus, if any, and treatment initiated. After delivery of the prescription, the source and other apparatus are removed. If any intraoperative reconstruction is indicated, it is performed, and the cavity is then closed surgically in a conventional manner.
[0014] If desired, radiation sensors can be mounted on the skin or on the applicator apparatus to assist in dose determination during the treatment planning process, or to monitor treatment to plan and/or warn of overdose during radiotherapy.
[0015] Although the description herein assumes x-ray therapy from miniature x-ray tubes, the apparatus may also be used with isotopes to similar effect. From the embodiments described herein, other features, apparatus configurations and procedures will be apparent to those of skill in the art. Such improvements are to be considered within the scope of this invention.
DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 depicts in cross section a simple cup embodiment of the invention positioned within the breast of a patient and sutured therein using suture tabs provided for this purpose.
[0017] FIG. 2 shows schematically in perspective a brachytherapy treatment system including an applicator apparatus of the invention.
[0018] FIG. 3 shows in cross section breast tissues gathered around the applicator with the cup, a lid and gasket assembled and a flexible extension of the source guide leading to an outside manipulator.
[0019] FIG. 4 is a perspective view showing a source catheter positioned in the manipulator and flexible source guide extension in preparation for controlled delivery of radiotherapy.
[0020] FIG. 5 is a perspective view showing schematically an applicator lid with provision for X/Y manipulation of the source guide, and control wires for connection to actuators for X/Y manipulation.
[0021] FIG. 6 shows schematically in cross section, detail of the applicator of FIG. 5 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] FIG. 1 shows in section view, a preferred brachytherapy applicator cup 10 positioned in an open surgical cavity 12 left in the breast 14 of a patient following (at least partial) tumor resection. The cup preferably is substantially rigid, of a predetermined shape (in this example circular), and preferably substantially transparent to x-rays and to visible light, or at least partially transparent to x-rays. It may, for example, be molded from engineering plastic, preferably with a specific gravity near unity to simplify treatment planning. Suitable materials would include polycarbonate, polyphenolene ether (Noryl, from GE Plastics, is an example) and polyethersulfone (Radel, from Solvay Advanced Polymers is another example). The shape can be generally circular-cylindrical, or other shapes.
[0023] If the tissues at the bottom of the cavity are susceptible to radiation damage and are to be protected, the material of the bottom portion 16 of the cup may further comprise the addition of attenuating fillers (see cross-hatching at bottom portion 16 ) to shield such tissues, or alternatively, an attenuating coating can be applied to the bottom of the cup. Barium compounds or metallic particulates may be used for filling purposes, but the separate filled and unfilled portions of the cup may require separate molding and subsequent joining together, as by bonding for example.
[0024] The distal bottom of the cup is positioned at the bottom of the cavity and if desired, secured with conventional sutures 18 to maintain cup orientation within the surgically created cavity. An optional flange or tabs 20 may be provided for suturing purposes. Alternatively, a base (not shown) to be located under the cup may be sutured similarly in the bottom of the cavity. The cup bottom can be retained to the base by a suitable releasable attachment means. For example, the base may comprise half of a conventional hook and loop fastener (VELCRO), to which a mating fastener portion secured to the outside of the bottom of the cup, such as by bonding, is used to anchor the cup in the cavity. In another variation where a base is used, the bottom of the cup could comprise half of either a screw-thread or snap-on fastener and be attached to the base by mating screw thread or snap-on fixation. It is also possible the cup could be inverted and its open mouth screwed onto such a threaded base, with apparatus described below emerging from the upper side, which would be the cup bottom. It is also possible to use a vessel which is permanently closed but with a top opening to accommodate the radiation apparatus described below; for small resection cavities the vessel could comprise a solid mass of plastic material with a guide channel extending into it from the outer side. The term vessel is intended to include such a configuration of an applicator.
[0025] In instances where the tissues under the cup are to be shielded from radiation, rather than filling the cup bottom with attenuating material, one or both portions of the hook and loop fastener or the base sutured to the bottom of the cavity may further comprise a shielding layer, for example a layer of metallic foil or filled polymer.
[0026] A range of applicator cup sizes and shapes may be offered as standard, from which the surgeon or radiation oncologist may choose to fit the patient's resection cavity, or in the alternative, and where there is sufficient time and information available, a cup can be fabricated which addresses a particular patient's requirement. Proximate to the cup's lip are screw threads 22 to mate with the lid (not shown in this drawing) presuming the cup is circular as shown. If the cup is not of circular cross-section, conventional over-center or snap-on fasteners can be used with features molded into the cup and lid for the purpose, which can be as in plastic food storage containers.
[0027] FIG. 2 shows the principal elements of the treatment system schematically. The elements comprise a treatment planning computer 24 used to create an optimized treatment plan based on the dose prescription and on cup shape, and if conventional imaging is performed prior to planning, also on other relevant information from the imaging data. Imaging information, particularly if by CT methods, may also reveal tissue conformance to the cup 10 and location of anatomy which may require shielding or other accommodation. The computer 24 may, in one form of the system, then provide the treatment plan to the controller (not shown) which manages control of the source output, source position spatially and the timing of exposure from radiation emissions in order to deliver the prescribed treatment. Parts of the computer 24 , controller and other elements of the treatment system communicate by conventional wiring 25 , and ultimately source positioning is controlled through a mechanical manipulator 26 which positions the source 28 as needed within the cup and therefore within the resection cavity. The computer and controller can be a single component, and the term “controller” as used in the claims and sometimes herein is intended to refer to either implementation.
[0028] With the preferred miniature x-ray tube sources, the source 28 is usually contained and carried within a source catheter 32 to which the source is rigidly affixed. The catheter 32 is shown positioned in the collet 34 on the sled 36 of the controlled portion of the manipulator. Where required, conventional fluid cooling apparatus (not shown) is provided, and cooling fluid is supplied at the manipulator apparatus from whence it flows to the x-ray source itself within the catheter.
[0029] The applicator 38 of the system comprises a tubular source guide 40 which is preferably rigid and transparent to radiation. The distal end 42 of the source guide is closed. Proximally, the source guide 40 is affixed to the lid 44 of the cup 10 . The source guide distal end 42 is thus positioned in the cup 10 when the lid is in place. The proximal end 45 of the source guide connects to a flexible extension 46 of the source guide that preferably is anchored to a stationary portion 48 of the manipulator 26 . This establishes a constant source guide lumen length from the manipulator to the source guide distal end 42 positioned within the applicator cup such that the controller can precisely control manipulation of the source 28 within the source guide 40 , in the manner of a control cable. The cup 10 and the lid 44 of the applicator 38 are shown assembled as if positioned in the patient's breast or the anatomy (not shown). The source guide portion within the cup is preferably straight, but need not be if necessary to accommodate a non-uniform prescription.
[0030] In explanation, control cables of the sort described above with respect to source manipulation are sometimes called Bowden cables, and comprise a flexible tubular outer sheath of fixed length, the ends of which are fixed to two different structures whose relative position need not be either constant or predetermined. Within the control cable sheath is a wire (or in this case, source catheter 32 ) which can be translated axially. Pushing or pulling a given amount on one end of the wire results in a substantially identical displacement at the other end of the wire. An automobile throttle cable is a common example of such a control cable.
[0031] In FIG. 3 the applicator 38 is shown submerged in a cavity of tissue such as a breast 14 . The tissues of the breast 14 have been gathered around the cup 10 and lid 44 and are held in place by conventional tape, sutures, or other conventional methods familiar to surgical practice. The lid 44 of the cup 10 is shown assembled to the cup with a gasket 49 , for example of silicone, positioned between cup and lid to seal the volume within. The lid has the central source guide 40 preferably affixed to the lid by conventional methods, an example of which is a collet 50 , and extending into the cup, with the proximal end 45 secured to the flexible extension 46 by a conventional clamp 49 . If necessary to protect the patient's skin and near-skin tissues from overdose which could result in adverse cosmesis, the lid can further comprise a skirt 51 of a shielding material extending coaxially inside the lip of the cup to a depth sufficient to protect the skin and near-skin tissues as shown. Alternatively, the cap's threaded skirt 51 a could include shielding material. A flexible drape 52 according to the teachings of U.S. patent application Ser. No. 11/323,331 is shown draping the breast 14 to protect attending personnel. The lid 44 may also be of a shielding material in order to provide radiation exposure protection to therapeutic personnel, either as a single molding as shown, or alternatively, the lid can comprise an assembly of parts. Depending on the attenuating properties of the lid elements, which include the threaded skirt 51 a, the attenuating skirt 51 may be redundant and can be eliminated. Also shown on the top of the lid is a vent 56 to permit air to escape from the interior volume of the applicator as the cup is filled with attenuating medium through an inlet port 58 .
[0032] FIG. 4 shows in greater detail the manipulator apparatus 26 . The proximal end of the source guide flexible extension 46 is mounted to the stationary portion 48 of the manipulator. The source catheter 32 is shown positioned within the collet 34 and extending into the source guide extension 46 . The source catheter 32 and hence the source (not shown) are controlled spatially by servomotors 61 of the manipulator in response to commands from the controller or computer. The manipulator shown schematically in FIG. 4 can accommodate both translation of the source axially within the source guide as well as rotation relative to the source guide, the latter for use with x-ray tubes emitting only through a solid angle (directional) rather than isotropically. In instances where isotropic source are used, only axial manipulation is required and the rotational capability of the manipulator 26 as shown may be eliminated. Furthermore, if it is desired to translate the source within the source catheter, a second manipulator (not shown) similar to the manipulator 26 may be added to operate in tandem with the manipulator 26 and provide independent control for both source and catheter.
[0033] FIG. 5 depicts schematically a lid embodiment and system where the top of the lid 62 comprises a membrane 64 , for example of silicone, to seal the volume within the cup 10 while the source guide (not shown) is translated in the X and/or Y directions by a servomotor positioning apparatus 66 mounted on the stationary portion 48 of the manipulator apparatus. Applicator guide rails 68 X, integral parts of the lid 62 , guide a X sled 70 X in the X direction, while the edges of the sled 70 X guide a sled 70 Y in the Y direction. Both sleds are controlled by servomotors 72 X and 72 Y respectively, acting through control cables 74 X and 74 Y of the sort described above. The servomotors 72 X and 72 Y are responsive to commands from the central controller. Collectively, this apparatus serves to keep the source guide parallel to the axis of the cup during X/Y translation. In principle such X/Y apparatus could be mounted entirely on the lid of the applicator, but given any substantial bulk or weight for the positioning apparatus, it is preferable to mount the positioning servomotors remotely, for example on the stationary portion 48 of the manipulator apparatus as shown.
[0034] In this embodiment, the proximal end of each of the control cable 74 X and 74 Y sheaths is affixed to the stationary portion 48 of the manipulator apparatus, as is the proximal end of the source guide flexible extension 46 . The source catheter 32 is mounted in the collet 34 and leads into the flexible source guide extension 46 . The distal end of the sheath of the cable 74 X is fastened to a mounting tab 76 on the lid 62 . The distal end of the sheath of cable 74 Y is mounted on a tab 78 , an integral part of the sled 70 X. The proximal ends of the inner wires of the two cables are controlled by the axial servomotors 72 X and 72 Y. The distal end of the inner wire of the cable 74 X is connected to a tab (not shown) proximate the central slot 80 X of the sled 70 X. The distal end of the inner wire of the cable 74 Y connects to a tab 82 on the sled 70 Y (see FIG. 6 for detail). With this arrangement, and together with manipulation of the source catheter 32 , the source may be positioned anywhere within the cup 10 by X,Y,Z coordinates which fall within the mechanical limits of the apparatus.
[0035] Although the source guide manipulation above is limited to X and Y translation, other manipulation strategies can be used, for example by pivoting an arm mounting the source guide 40 , where the radius of the source guide from the pivot and the pivot angle are controlled. It is also possible to vary the angle of the source guide axis relative to the cup axis. Servomotors can be used to control the positions of all these variations in keeping with the degrees of freedom of motion provided by the apparatus. Still other control schemes will be readily apparent to those of skill in the art. If desired, closed loop feedback control for each degree of freedom employed can be provided easily, for example by use of linear variable differential transformer (LVDT) sensors, the output of which can be used to verify position with precision. Sensor outputs can also be used to verify treatment to plan. Such methods are known to those of skill in the art.
[0036] FIG. 6 is a cross section detail through the axis of the source guide 40 , looking in the X direction. The membrane 64 is shown clamped onto the source guide 40 by a clamp 84 . The mounting of the sled 70 X on the rails 68 X is seen in FIG. 6 .
[0037] Various embodiments employing combinations of features described above are useful for IORT. The simplest case is a source guide positioned in a fixed position within a cup of circular cross-section, and a substantially isotropic source in a fixed position or translated within the source guide. Special circumstances can be accommodated with other embodiments. For example, if the resection cavity from tumor removal results in a cavity which is not centered on the tumor location, as discussed above, perhaps as a result of successive adverse pathology findings or for any other reason, the prescription can be centered on the tumor location by use of a source guide passing through the tumor location rather than being centered within the cavity. The cup and lid can still be chosen to fill the cavity, be it round or oval in cross section, or of another shape. Since the likelihood of disease infiltration into apparently normal tissue decreases with distance from the tumor, when using this approach, the farthest tissues from the tumor will receive a lighter dose. To the extent that a portion of the target tissue limits fall within the cup, the tissues beyond may receive very little dose, while the tissues nearer the tumor will receive the full prescription. With the embodiment described in FIG. 5 , the isodose pattern circumscribing the prescription may be sculpted beyond shapes available from a fixed source position or from a linear source guide within which the source is translated.
[0038] Although described particularly in relation to breast radiation, the applicator and accompanying control apparatus can be used at other tissue locations wherein a resection cavity or other cavity is open at the skin.
[0039] The embodiments described above will suggest to those of skill in the art, other combinations of features which, when combined, will result in further embodiments. These embodiments are to be considered within the scope of the invention.
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A device for administering brachytherapy to a patient includes a vessel that may be in the form of a hollow cylindrical cup, for fleshing into and substantially filling the open-ended cavity. The vessel has a closed outer end, which may be a removable cover, and a source guide penetrates the closed outer end so as to extend deep into the vessel, to receive a radiation source in the source guide. A manipulator can be connected to the radiation source, and also to the source guide, for allowing several different types of manipulation of the source orientation and position within the vessel during the brachytherapy procedure.
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DESCRIPTION
1. Field Of The Invention
The subject invention pertains to grain roaster/coolers, and more specifically to one having a preheater.
2. Description Of Related Art
In many cases, grain is passed through a roasting process to help sterilize the grain and inhibit the growth of mold and fungus. The grain is typically heated by an open flame as the grain is conveyed through a rotating drum. After roasting, an air cooled cooler is often used to cool the grain back down. A typical cooler uses a chain driven paddle wheel type conveyor to pull the grain across a perforated plate through which ambient air passes.
There are two major problems with today's roaster/coolers. A tremendous amount of heat is wasted in the roasting process. Secondly, the paddle wheel type conveyor tends to lump the grain together. This unequal distribution of the grain causes uneven and incomplete cooling.
SUMMARY OF THE INVENTION
To avoid the problems with present methods of roasting and cooling grain, it is an object of this invention to recover dry waste heat otherwise radiated from the drum to the atmosphere and use it in preheating moist grain before it enters the roasting drum.
Another object is to partially encapsulate a roaster's hot drum in an insulated shell to keep the exposed surface temperature of the roaster at a safe level. The lower surface temperature becomes an additional advantage when the roaster is operated indoors on an uncomfortably hot day.
Another advantage of encapsulating the rotating drum within a non-rotating shell is that an operator is shielded from moving parts that could cause injury.
Another object is to preheat grain with relatively clean dry air.
Another object is to preheat grain by discharging heated air directly into the grain to help fluidize the grain as it travels to the roaster.
Another object is to control the amount of preheat to avoid overheating the grain.
Another object of the invention is to equally distribute roasted grain over a cooling conveyor to ensure even and complete cooling.
These and other objects of the invention are provided by a novel roaster/cooler that includes a preheater that extracts heated air from between a hot rotating drum and an outer stationary shell, and delivers that heat to preheat the incoming grain. To complete the process, the roasted grain is evenly spread across a fine meshed conveyor through which relatively cool air passes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a schematic cross-sectional side view of the invention.
FIG. 2 is a schematic cross-sectional top view of a portion of the cooler with the grain omitted.
FIG. 3 is an enlarged view of a portion of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Structure
A roaster/cooler system 4 of FIG. 1 includes a roaster 6 pivotally mounted relative to a cooler 8. Roaster 6 includes a generally stationary insulated shell 10 with a rotatable drum 12 inside. Drum 12 rests on a drive roller assembly 14 and is rotatable about its longitudinal center line 16. A gas burner 18 mounted to shell 10 serves as a heat source that discharges into drum 12. Combustion fumes are expelled from drum 12 and shell 10 through exhaust 20.
In one embodiment of the invention, a hopper 22 serves as a grain transferring device 24 that supplies roasting drum 12 with grain 26. Hopper 22 includes a lining of finely perforated plate 28. Hopper 22 is coupled to roaster 6 by way of a preheater 30.
Preheater 30 includes a fan 32 that draws from an air gap 34 between shell 10 and drum 12. Fan 32 also draws in ambient air 36 through adjustable damper 38. Fan 32 discharges into hopper 22 and through its perforated lining 28 which is attached to its side wall 40. Make up air 36 is drawn into air gap 34 via air inlet 44.
Roaster 6 pivots about a pin 46 (a pivot point) upon varying the height of roaster 6 at jack 48. In one embodiment of the invention, pin 46 and jack 48 are attached to cooler 8.
Cooler 8 includes a housing 50 with a grain inlet 52, a grain outlet 54, an air inlet 56 and an air outlet 58. Inside housing 50 is a conveyor 60 supported by a perforated plate 62, a drive roller 64 and an idler roller 66. Conveyor 60 conveys grain 26 from inlet 52 to outlet 54. Grain inlet 52 of cooler 8 is in fluid communication with a roaster outlet 68. Grain outlet 54 of cooler 8 includes a discharge auger 70 that conveys grain 26 out of cooler 8.
A cooling fan 72 forces ambient air 36 through air inlet 56, up through conveyor 60, and out through air outlet 58.
Operation
Grain 26 at a first temperature enters hopper 22 at a transfer inlet 74. Grain 26 is conveyed by a feed auger 76 through a conduit 78 and is expelled at a second temperature through a transfer outlet 80. Here grain 26 enters drum 12 at a roaster inlet 82. The flow rate of grain 26 entering drum 12 is modulated by feed auger drive motor 84 in response to the temperature inside drum 12 as sensed by a temperature sensor 86. The flow rate is increased with an increase in temperature. In addition, if the temperature inside drum 12 becomes excessively hot, gas valve 88 shuts burner 18 off in response to temperature sensor 90 detecting a predetermined upper temperature limit.
Roller assemblies 14 rotate drum 12 which causes grain 26 to travel the length of drum 12. As grain 26 passes through drum 12, burner 18 raises the surface temperature of grain 26 up to a third temperature upon grain 26 reaching roaster outlet 92.
During the roasting process, the exterior surface 94 of drum 12 becomes hot, causing heat to radiate outward. This heat is captured in air gap 34 between drum 12 and shell 10. Fan 32 draws hot air out of air gap 34 and discharges in into a plenum 96 defined by the space between perforated lining 28 and a side wall 40 of hopper 22. The heated air passes through perforated plate 28 and preheats grain 26 as it passes through grain 26 in hopper 22.
If the air temperature in plenum 96 gets too hot, as measured by temperature sensor 98, damper 38 opens to mix cooler ambient air 36 with the air drawn from air gap 34. The degree of opening of damper 38 is controlled by damper drive motor 100 in response to sensor 98.
It's been found that adequate preheat operation is realized when the roast heat to preheat ratio is less than 10 where the roast heat to preheat ratio is defined as the roast heat temperature differential divided by the preheat temperature differential. And the preheat temperature differential is defined as the temperature of the grain at transfer outlet 80 minus the temperature of the grain at transfer inlet 74, while the roast heat temperature differential is defined as the temperature at roaster outlet 92 minus the temperature at roaster inlet 82. It should be clear that transfer outlet 80 and roaster inlet 82 is a transitional point of substantially equal grain temperature. It should also be noted that the grain temperatures mentioned herein are average temperatures of the grain surface as measured by a thermometer immersed in grain aggregate.
Once grain 26 is roasted, it leaves roaster 6 through outlet 92 and enters cooler 8 through grain inlet 52. Grain 26 falls onto conveyor 60. Conveyor 60 is a link belt type conveyor having numerous belt openings as shown in FIG. 2. In one embodiment of the invention, belt 60 is a Model A2 with a 1"×1" mesh manufactured by Ashworth Bros., Inc., of Winchester, Va. Grain 26 falls into openings 102 but is prevented from falling completely through by perforated plate 62 which lies underneath belt 60. Plate 62 has small air passage perforations 104 that are generally too small for grain 26 to fall through. In one embodiment of the invention, perforations 104 are 5/32 inches in diameter. In another embodiment of the invention, perforations 104 are 3/32 inches in diameter.
As belt 60 pushes grain 26 over plate 62 in the direction indicated by arrow 106, grain 26 is evenly spread out by a grain spreader 108. Spreader 108 is a bent plate having a nose portion 110 upstream of two wing portions 112.
As grain 26 continues to travel downstream of spreader 108, grain 26 is cooled by a current of air 114 passing upward through perforations 104 of plate 62 and through openings 102 of conveyor 60. This current of air is generated by fan 72. It's been found that for even and complete cooling the ratio of the area of the average perforation 104 of plate 72 divided by the average opening area 102 of belt 60 is in the range of 0.002 to 0.08. FIG. 3 shows perforations 104 being smaller than opening 102, but for clarity the two areas are not drawn to scale.
Once grain 26 is cooled, conveyor 60 drops grain 26 onto discharge auger 70 which discharges grain 26 out of roaster/cooler 4 through grain outlet 54 to complete the process.
The use of the term "grain" used herein refers to the seed or fruit of any plant. Examples of grain include but are not limited to: soybean, rice, beans, corn, oat, sunflower, cotton, milo, and coffee. The term "preheater" used herein refers to any one of a variety of means for delivering heat from the roaster to the grain before it enters the roaster. The one described herein is lust one example of a preheater. Examples of other preheaters well within the scope of the invention include but are not limited to: conventional heat exchangers, tube and shell heat exchangers, fin and tube heat exchangers, stacked plate heat exchangers, and heat pipes. The use of the term "grain transferring device" used herein simply refers to any device used in delivering grain to the roaster.
Although the invention is described with respect to a preferred embodiment, modifications thereto will be apparent to those skilled in the art. Therefore, the scope of the invention is to be determined by reference to the claims which follow:
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A grain roaster/cooler includes a fuel saving preheater and a roasting drum that rotates within a stationary housing. Heat radiated from the drum is captured in the form of hot air trapped in an air gap between the drum and the housing. A fan draws from this hot air supply and discharges through the incoming grain being supplied to the roaster. The incoming grain is thus preheated as it recovers heat that would have otherwise been lost.
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BACKGROUND OF THE INVENTION
With high grade coke becoming scarcer and much more expensive, the need for its conservation continues to grow. Various methods have been tried to diminish coke consumption without much success. The Coal Reactor in its ability to generate clean carbon monoxide quite economically, even from poor quality fossil fuels, provides the basis for achieving this goal. An elementary theory allows an estimate of the coke saving possible under reasonable operating conditions with resulting diminished impurities in pig iron. A more illuminating theory based upon complete chemical reactions that are energetically self-sustaining yields the same simple formula in the limit where no direct ore reduction occurs.
The relationship deduced from the cost effectiveness of having steam coal burned in the Coal Reactor to generate CO and using correspondingly less coke in the blast furnace is:
D=(2Wd.sub.1 +Vd.sub.2)/(2W+V)
Where V and W are the relative amounts of CO and O 2 and d 2 and d 1 denote the cost for steam coal and coke, respectively. In the limit of V→0, the cost for the coke alone enters; quite clearly at some critical value of the CO/O 2 ratio, fed via the tuyeres into the combustion zone, an inadequate heat balance occurs beyond which no further coke saving is possible.
Thus, to be sure that a realistic case is employed in estimating V, the composition 79% (by volume) CO and 21% O 2 is chosen, corresponding to the satisfactory heat balance for the conventional air blown blast furnace; in the example considered, oxygen rather than air is mixed with CO in the combustion process. For d 1 =$100/ton and d 2 =$30/ton, the value of D becomes 55/ton, reflecting an effective addition to the blast furnace of a mix of approximately 35% coke and 65% steam coal. However, by the device of burning cheaper coal in a separate reaction vessel, the Coal Reactor, a greater dilution of the coke is obtainable than is what is possible otherwise, since the direct addition of coal to the blast furnace is limited to about 15%. Beyond this range, the mechanical strength for the charge column is too greatly diminished, related to a significant reason why coke must be used instead of coal in the first place.
Generating a portion of the CO outside the blast furnace further means cleaner operation with proportionately less sulfur and other impurities in the pig iron itself, a circumstance favorable for production of higher quality steel. A much more sophisticated theory of the blast furnace underlies the present innovation. An entirely new discipline of econochemistry has been discovered of which econometallurgy is but a part. The competition between direct and indirect ore reduction, together with the slag chemistry out of which the energetics and diagnostics derive can thus be taken into account.
All this relates to the correct manner of evaluating the materials/energy balance for the blast furnace which today still rests on the chemical engineering and process embodiment of uncoupled reactions deriving from the Lavoisier concept of independent balanced chemical equation. The present invention cannot be properly understood in the old light, and perhaps explains why blast furnace technology has languished.
SUMMARY OF THE INVENTION
Bringing the Coal Reactor and the blast furnace together in the symbiotic fashion indicated, demonstrates the great significance in the new science of coupled chemical reactions in self-sustaining systems. The present invention illustrates how such variance of vertical shaft furnaces can cooperatively be operated to derive benefits not otherwise attainable. In the absence of ore reduction, the Coal Reactor can perform more effectively in the production of energy, partly as heat and the remainder as a clean gas; requiring a slagging action different from what must be required for the blast furnace itself.
In other words, the blessings of the Coal Reactor invention, (U.S. Pat. No. 4,004,895 which discloses a method for the clean combustion of sulfur bearing coal in the presence of limestone in a substantially closed system consisting essentially of said coal and said limestone to provide a slagging action for removal of ash and sulfur bearing compounds resulting from said burning and having a reducing atmosphere thereby preventing the formation of sulfurous oxides and producing a fuel gas. The gas is comprised substantially of approximately 60-65% nitrogen and 30-35% carbon monoxide with trace amount of carbon dioxide, hydrogen and water vapor.) can contribute to modernization of the iron and steel industries, offering a substantial benefit in improving the efficiency and overall technology of blast furnace practice.
DETAILED DESCRIPTION OF THE INVENTION
The size of a Coal Reactor must match that of a blast furnace, which means that the former needs to consume thousands of tons daily with the prospect of huge power production as even larger blast furnaces emerge pursuant mounting efficiency of pig iron production associated with diminishing surface to volume ratio. In fact, the Coal Reactor unencumbered by ore reduction can have an even more favorable surface to volume ratio stemming from a shallower bed in a squat appearing furnace.
Excess fuel gas left over, after the CO supply to the blast furnace is properly adjusted, can be combined with the resulting enriched blast furnace gas, to not only operate the facility, but also furnish power as an auxiliary utility station. Where the local demands for energy justify a large excess of coal reactor gas, the combined operation of power production and steel manufacture could mean significant economic gains.
It should be noted that some hydrogen will accompany CO from the release of moisture and pyrolytic decomposition products in the Coal Reactor. When the actual composition of the gaseous products fed into the blast furnace is known, the appropriate correction can be made in the detailed econometallurgical analysis incorporating the modified coupled chemical equation. In ensuring the production of clean gas, a feed back mode of operating the Coal Reactor can be employed (U.S. Pat. No. 4,080,196) to redirect the gas stream from the cooler portions of the furnace on a return path through the calcination zone where the slagging action occurs. Thus, a much hotter gaseous effluent from the coal reactor results to make it even less likely that the conventional blast furnace stoves normally used to preheat the air blast, will be necessary to maintain an adequate head balance supportive of steady state operation.
What also is apparent is the absence of nitrogen throughout with air replaced by oxygen. By careful attention to the heat balance, there is no need to overheat the refractory walls in the vicinity of the tuyeres where the highest temperatures arise within the combustion zone. Since the blast furnace in the present arrangement will tend to be freer of impurities, particularly the abrasive ash components, the lining ought to experience enhanced durability. Furthermore, with fluxing action shared by the Coal Reactor, less lime stone with subsequent smaller slag volume accompanies the dualistic vertical shaft furnace operation of the blast furnace itself.
A particularly exciting feature is the production of a greater slag volume from the Coal Reactor having a composition better suited for encapsulation of toxic wastes, only recently described in other innovative patent applications (Ser. Nos. 30,991 and 30,992).
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Coke consumption may be cut as much as fifty percent using a coal reactor to furnish carbon monoxide for ore reduction in a blast furnace while lowering the sulfur content of pig iron accompanied by a smaller slag volume.
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BACKGROUND OF THE INVENTION
The device of this invention relates to the field of vegetable dewatering. Specifically the device of this invention by a unique and simple design dewaters only the outer surface layers of the vegetable material. This process of dewatering greatly improves the shelf life of the vegetable matter while at the same time greatly reducing the period required to re-hydrate the vegetable so that it may be used in salads and so forth, principally in the fast food industry.
The inventor knows of no prior art which accomplishes the function of his invention in the same manner and by use of the same structure.
The inventor finds no instance in the following patents of the combination of air jets and vacuum along with an absorbent surface that he discloses. The closest reference is the prior art disclosed in the Cothran U.S. Pat. No. 2,472,794. Columns 3 and 4 Cothran do discuss the use of blasts of air along with contact to an absorbent material (with no vacuum) but Cothran teaches that these methods are ineffective. Cothran itself relies not upon concentrated air blasts but on air blown by a fan through an open hood and there is no absorbent material or vacuum chamber. Cothran does not disclose any references beyond those in columns 3 and 4, which Cothran says are ineffective, that show the use of a blast of air in conjunction with absorbent material. Cothran does not anywhere disclose the use of a vacuum chamber.
The Prater U.S. Pat. No. 3,113,875 has a good many air ducts but no blast except in FIG. 4 where there is no mechanical conveyor. The dried onions are conveyed by the air stream in that figure. Where there are conveyors there is no absorbent material and no vacuum chamber. Fouineteau U.S. Pat. No. 3,885,321, is simply a spin dryer. The Yamazaki U.S. Pat. No. 4,059,046, is not a dryer at all. Conveyors carry snack food through a deep fat frying tank and then through a cooler with the entire operation being conducted in a vacuum chamber. The only reference to drying is before the material reaches the apparatus. The Bingham U.S. Pat. No. 4,114,286 is yet another spin dryer. The Rose U.S. Pat. No. 4,352,249, merely uses a hood to direct curtain-like air streams. Probably the best drawing is a FIG. 6, which is described at column 5. The fruit is not sliced but has intact skins so that the drying problem is substantially different from that present with sliced fruit or vegetables. There is a discussion of slightly lower pressure in the drying chamber but there is no low pressure chamber below an absorbent surface to pull water through it, and no sliced work pieces which are exposed to air jets above and a vacuum chamber below the conveyor. In this prior art patent any vacuum disclosed surrounds the conveyor.
SUMMARY OF THE INVENTION
The term "dewater" means removal of water from the surfaces of the vegetables or workpieces in a range from removal of surface water only to some dehydration of the workpieces. This term, "dewater", has this meaning throughout, including the detailed description and claims.
This machine is designed to dewater the outer surfaces of vegetables, especially cut vegetables. This partial dewatering greatly extends the shelf life of the vegetables.
The machine is comprised of plenums, blowers, directional air nozzles, a vacuum chamber with a perforated housing, a continuous conveyor belt, and rollers on which the conveyor belt is mounted. The conveyor belt is comprised of layers. The top layer is a muslin belt. Attached to the underside of the top layer are strips of hook and loop fastener material. Directly below the muslin belt is a plastic belt that is made of an inter woven plastic material on top of which are mounted strips of complementary hook and loop material. The hook and loop fastener materials are what hold the muslin belt to the plastic belt. Other fastening systems may be used. The purpose of the hook and loop fasteners is to make it easy to change the muslin belt. This is necessary because the vegetable matter accumulating in the muslin is usually so great that eventually the muslin belt is removed for cleaning, or replaced due to wear. A fresh muslin belt is required and can easily be put in place in order to maintain the machine operations at maximum efficiency.
The muslin belt provides a highly absorbent surface having fine perforations which allow water to pass through but keep the vegetable matter on the conveyor belt. The plastic belt forming the bottom of the conveyor belt provides a surface having large perforations that will allow water to pass through and yet is durable enough to withstand the constant contact with the rollers that is required in order for the whole belt to function properly.
The machine functions in the following manner:
The blowers force large amounts of air into the plenums. Through one plenum air blows through directional nozzles located above the conveyor belt. This air blasts out in a high velocity stream which drives the water from the surface layers of the vegetable matter. This air velocity is so great that it would blow the vegetable matter from the belt if it were not for the vacuum chamber beneath the belt. The muslin absorbs or wicks water from the lower surface of the vegetable pieces. The vacuum chamber blowers remove the water through the conveyor belt and through the perforated housing of the vacuum chamber beneath the conveyor belt into the vacuum chamber itself. Within that vacuum chamber is an opening to which a blower is attached. This blower removes the air containing the water that was forced from the vegetable matter from the vacuum chamber. The combined effect of the continuously high velocity stream of air from the nozzles above the conveyor belt and the suction from the blower below the conveyor belt provides an efficient and unique system by which the outer surface layers of the vegetable matter are dewatered to the desired degree.
The vacuum created by the blower is sufficient so that the vegetable matter sticks to the muslin conveyor belt while surface water is absorbed by the muslin and removed by the air flow. In order to remove the vegetable matter pieces from the muslin conveyor belt a directional nozzle is located at the end of the muslin conveyor belt. The belt passes over a roll of small diameter to help free the vegetable pieces. As the vegetable matter approaches the small radius turn of the conveyor belt a continuous stream of high pressure air from another blower, through another plenum, is blown out of this directional nozzle at a tangent to the surface of the roller. This air causes the vegetable matter that is stuck to the muslin conveyor belt to be dislodged and blown onto a moving perforated aeration bed belt and expose product pieces to an air blast from below the belt for further drying, and for movement toward a packaging station. The moving aeration belt is provided with a pattern of smaller openings mixed with groups of larger openings forming the corners of squares, and larger openings at the center of each square to further remove water from the vegetable pieces.
The conveyor belt, after the vegetable workpieces are released, passes over a curved surface of the vacuum chamber which is perforated. Air passing through the belt and into the vacuum chamber further dries the muslin and makes it ready to receive more wet vegetable workpieces.
The following detailed description will show the structure and function of the invention in its most preferred embodiment.
DESCRIPTION OF THE DRAWINGS
FIG. 1 a top plan view of the machine.
FIG. 2 is a side elevational view of the machine with the blower superimposed over it.
FIG. 3 is a side plan view showing the relationship of the conveyor belt and the directional nozzles.
FIG. 4 is a top plan view of the conveyor belt without the muslin covering.
FIG. 5 is a view from line 5--5 of the figure.
FIG. 6 is a view from line 6--6 of FIG. 3.
FIG. 7 is a side cut-a-way view of the conveyor belt showing the different layers.
FIG. 8 is a close up view of the perforations in the conveyor belt on the aereation bed.
DETAILED DESCRIPTION
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
The device of the invention is a machine for partially dewatering the outer layers of vegetables. Specifically, the machine 10 dewaters the exposed outer surfaces of vegetables. The surface dewatering of vegetables is designed to enhance their shelf life. Referring to FIGS. 1, 2 and 3, the machine 10 is comprised of two blower plenums 30 and 31, a suction blower 33, two blowers 34 and 35, eight water removal nozzles 36-43, a dislodgment nozzle 45, a multi-layer conveyor belt 50, five rollers 55-59, a vacuum chamber 80, and an aereation bed 70.
FIGS. 2 and 3 illustrate the locations of the blowers 35 and 34, the suction blower 33, and the blower plenums 30 and 31.
Referring to FIG. 3, the relationship between the opening 32, the conveyor belt 50, the vacuum chamber 80, and the water removal nozzles 36-43 may be seen. The opening 32 of the suction blower 33 is contained within the vacuum chamber 80. Located directly above the conveyor belt 50 are the water removal nozzles 36-43. As illustrated by FIG. 6, the openings 90 to the water removal nozzles are narrow slots rectangular in shape. Furthermore, the openings 90 of the water removal nozzles are of such width that the entire width of the conveyor belt 50 that travels under each water removal nozzle 36-43 is covered by the blast of air that comes out of each nozzle 36-43. The water removal nozzles 36-43 are supplied with air from plenum 30 by the blower 34; see FIGS. 1 and 3.
Referring to FIG. 3, the vacuum chamber 80 has a perforated top plate 81 and a perforated curved portion 82. The perforated top plate 81 allows the water that is passing through the conveyor belt 50 to be pulled into the vacuum chamber 80. The perforated top plate 81 also allows the suction force of the vacuum chamber 80 to hold the vegetables on the conveyor belt 50. The perforated curved portion 82 allows the suction force of the vacuum chamber 80 to further dry the conveyor belt 50. It is important to note that if the vacuum chamber 80 did not provide sufficient suction to hold the vegetables on the belt 50 that the air blast from the nozzles 36-43 would cause the vegetables to be blown off the belt 50.
Still referring to FIG. 3, but also referring to FIG. 7, the conveyor belt 50 may be seen. The conveyor belt 50 is comprised of layers 51 and 54. The top layer of the conveyor belt 50 is a muslin cloth 51. The bottom layer of the conveyor belt 50 is a plastic belt 54. The muslin 51 is attached to the plastic belt 54 by means of hook strips 52 and loop strips 53 that are located between the muslin 51 and the plastic belt 54, the hook strips being sewn or attached directly to the muslin belt 51 and to the loop strips 53 being attached directly to the plastic belt 54. The muslin 51 is a material that is water absorbent and finely perforated due to the weave to allow water to pass through it. The plastic belt 54 is comprised of an interwoven network of plastic links 73; as illustrated in FIG. 4 and FIG. 5. These links 73 have large spaces between them in comparison to the perforations between the threads in the muslin 51. Other strong perforated structures could be used.
The muslin 51 is a material that is water absorbent and has fine perforations that allow water to pass through it but the perforations do not to allow the vegetables to pass through it. The large spaces in the plastic belt 54 also allow water to pass through the plastic belt 54. The hook strips 52 and the loop strip 53 are spaced so that they do not interfere with the passage of water through the muslin 51 and the plastic 54. The conveyor belt 50 is continuous, as illustrated in FIG. 3, and is stretched over the five rollers 55-59. Roller 57 provides the power that causes the belt to move.
Still referring to FIG. 3, dislodgment nozzle 45 may be seen at the end 60 next to the roller 57 of the conveyor belt 50. The nozzle 45 is pointed at an angle generally tangent to the surface of roller 57. The orientation of the nozzle 45 is such that the blast of air that is directed toward the end 60 will be an upward blast of air blowing the vegetable matter onto the aereation bed 70. Nozzle 45 is supplied with air from plenum 31 by blower 35. Also, a roller 57, located at end 60, over which the conveyor belt 50 rolls, is of a small diameter. The small size of the roller 57 means that the surface of the vegetable matter that is in contact with the belt 50 will be tangent to the surface of the belt 50 as it moves over the roller 57. This allows the air blown through nozzle 45 to more easily dislodge the vegetables from the belt 50.
Referring now to FIGS. 1 and 2 the relationship of the conveyor belt 50 and the aereation bed 70 may be seen. The conveyor belt 50 and the aereation bed 70 are located adjacent to each other with end 60 of the conveyor belt 50 being parallel to end 65 of the belt 71. The aereation bed 70 is comprised of a surface 71 that is mounted over posts 76-79 are attached at pivots 73 [not shown] to belt 71 and the plenum 72. The belt 71 is perforated; see FIG. 8. The perforations of the belt 71 are in rows that alternate between small perforations 74 and large perforations 75. The pattern of perforations is disclosed in FIG. 8 and is considered optimum for maximum product exposure to air blast. The posts 76-79 by moving in a back and forth motion shake any water still in contact or surrounding the vegetable loose. The water draining through perforations 74 and 75 and in to the plenum 72. The machine 10 works in the following manner:
Referring to FIG. 1, vegetables, for instance carrots, are sliced in a slicer (not shown), travel down aereation bed conveyor 100, and are deposited evenly on the conveyor belt 50. As the vegetables move down the conveyor belt 50 the nozzles 36-43 blast air onto the vegetables at such a velocity that the outer surfaces of the vegetables are dewatered. The water that is removed from the vegetables by the air blast from the nozzles 36-43 is partly evaporated and partly absorbed by the muslin and sucked through the conveyor belt 50 and out through the opening 32 by the suction blower 34. The suction upon the belt 50 is so great that the vegetables remain on the belt 50. To dislodge the vegetables from the belt 50 the nozzle 45, located at the end 60 of the conveyor belt 50 between the conveyor belt 50 and the aereation bed 70, is used. Air is pushed through the nozzle 45 at high velocity and the vegetables that are stuck to the conveyor belt 50 are removed and turned and deposited on to the aeration bed belt 70. Further water removal to the desired degree, is accomplished as the product travels through the aereation bed on surface 70. The perforations in surface belt 70 are designed to provide maximum exposure of the product to the air blast.
An over all pattern of smaller holes 74 is interrupted by patterns of larger holes 75 at the corners and centers of squares. The water remaining to achieve dewatering, is removed from the vegetables as they are carried over the surface 70 on the aeration belt 71. The water travels through perforations 74 and 75 in the shaker 71. These perforations are designed to give maximum water removal capability to the aeration belt 71.
The above described embodiments of this invention are merely descriptive of its principles and are not to be limiting. The scope of this invention instead shall be determined from the scope of the following claims, including their equivalents.
For the purpose of simplicity, the word absorbent, as used in the claims, shall include within its meaning the meaning of the word adsorbent. Also the terms gas and liquid are intended to have their plural as well as their singular meaning.
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A device for drying pieces of food comprising a series of blowers, an absorbent multi-layered conveyor belt, and a aereation bed. Two blowers providing a blast of air and a suction, respectively, that pulls the water from the outer layers of the food through the absorbent conveyor belt and out of the machine. Another blower being positioned to blow the food pieces off the end of the conveyor belt on to the aereation bed for further processing and packaging. Another nozzle being positioned to blow the food pieces off the end of the conveyor belt on to the aereated (aereation) bed for further processing.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. provisional application No. 60/711,902 filed Aug. 26, 2005.
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. provisional application No. 60/711,902 filed Aug. 26, 2005.
Genus and species of plant claimed: Ribes nigrum.
Variety denomination: Blackadder.
BACKGROUND TO THE INVENTION
The new variety of blackcurrant, Ribes nigrum, was created during the course of a planned plant-breeding program carried out at Lincoln, New Zealand. The new variety was selected from a population of seedlings derived from a controlled cross that was made in 1998, between L20 (unpatented), the seed parent, and L31 (unpatented) the pollen parent. Both parents originated from the breeding program in New Zealand.
Seed from the cross was sown in the field in 1999, in Canterbury, New Zealand. The original plant of the new variety was selected during the 2000-2001 summer.
The new variety was asexually reproduced at Lincoln, New Zealand as hardwood cuttings in winter 2001 and planted into a selection plot for further evaluation. The resulting plants propagated true to type, demonstrating that the characteristics of the new variety are stable and are transmitted without change through succeeding generations.
The new variety is able to be distinguished from its parents on the basis of flowering time. It flowers earlier than both L20 and L31. L20 is resistant to gall mite, the new variety is susceptible. The titratable acidity levels are higher in fruit of the new variety than levels in both L20 and L31. The new variety has also been observed to display less glossy leaves, and less of an upright and vigorous growth habit, compared with the blackcurrant variety Magnus. The new variety flowered earlier and yielded more fruit than Magnus. In comparison with other blackcurrant varieties grown in New Zealand, Bed Ard and Ben Rua, the new variety has been observed to flower earlier than either variety.
SUMMARY OF THE INVENTION
The major characteristics that the new variety exhibits are:
(a) A vigorous, upright growth habit (b) Early bud burst, flowering and maturity, where winter chilling exceeds 1000 hrs below 7° C. (c) One-year old wood in winter is orange-brown (d) The vegetative buds in winter are slightly held out and are ovate in shape. (e) Ability to bear black, round fruit of good quality in high yields, well suited to juice. (f) Susceptible to gall mite.
BRIEF DESCRIPTION OF THE DRAWINGS
The following figures show typical specimens of the new variety in colour as true as is reasonable possible.
FIG. 1 : Upright growth habit of bush, typical of the blackcurrant variety ‘Blackadder’.
FIG. 2 : Colour of wood of one-year old shoots, typical of the blackcurrant variety ‘Blackadder’.
FIG. 3 : Typical fruit of blackcurrant variety ‘Blackadder’.
FIG. 4 : Typical plant of blackcurrant variety ‘Blackadder’.
FIG. 5 : Close up view of typical fruit of blackcurrant variety ‘Blackadder’.
FIG. 6 : Vegetative buds in winter, typical of blackcurrant variety ‘Blackadder’.
DETAILED DESCRIPTION OF THE INVENTION
The following is a detailed description of the new variety. The specimens described were grown in Canterbury, New Zealand. The observations were made in the 2005/2006 season, on plants that were planted in 2001 and managed under standard farm practices.
Horticultural terminology is used in accordance with UPOV guidelines for blackcurrant. All dimensions in millimeters, weights in grams (unless otherwise stated). Colour references refer to the R.H.S. Colour Chart, The Royal Horticultural Society, London. (4 th edition, 2001).
Plant and Foliage
The plant exhibits an upright growth habit, although over the harvest period the branches tend to branch out with a full crop. Four year old bushes commonly have a height around 1000 mm, and a width of approximately 1000 mm, although this may vary with growing conditions. The number of basal shoots in unpruned, four year old bushes is typically around 6. One year old wood in winter is an orange-brown colour (greyed orange group 167A). Dormant buds are slightly held out in relation to the shoot. The buds are medium in length around 0.9 cm, ovate in shape and the shape of the bud apex is obtuse. The buds have a medium intensity of anthocyanin colouration and bloom. Young vegetative shoots have a medium intensity of anthocyanin colouration.
The first mature leaf typically averages approximately 90 mm in length and approximately 90 mm in width. The overall leaf shape is 5 lobed with a terminal central lobe, 2 lateral and 2 basal lobes with an acute leaf apex. The leaf base is cordate in shape and moderately open. The leaf margin is serrated. The upper surface of the leaf is medium green in colour (green group 137A) with moderate gloss. The venation is reticulate, does not differ significantly in colour from the upper surface of the leaf. The lower surface has no pubescence. The leaf petiole of the first mature leaf is yellow-green in colour (near 144B) and has weak anthocyanin colour at the base and distal ends. It is typically 60 mm in length. There is no readily discernible difference between flower and vegetative buds prior to budbreak.
Inflorescence
Flowers are configured in an inflorescence and are hermaphrodite. The attitude of the inflorescence is outwards in relation to the shoot. Predominantly the number of inflorescences per bud is usually at least 2. The length of the inflorescence typically averages 50 mm and the number of flowers per inflorescence typically averages 8. The petals of the flowers are not noticeable compared with the five sepals which are much larger than the petals. The flower diameter is typically around 8 mm. The intensity of anthocyanin colouration of the sepal is weak and of the ovary, absent to very weak. The flowers have no fragrance.
Fruit
The fruit are overall medium in size, averaging 0.8 g in weight and 10 mm in diameter. The degree of variability in berry size is moderate, fruit weights typically ranging from 0.5-1 g. The fruit colour is black (black group 202A) and has medium glossiness. The fruit are round in shape. The flesh color is pale green (near greyed-green 192D).
At maturity the fruit sweetness averages approximately 16° Brix. Ascorbic acid levels are medium, ranging from 125-150 mg/100 g and the total anthocyanin content is typically around 460 mg/100 g. Yields are high averaging approximately 15 tonnes/hectare under New Zealand growing conditions.
Cultivation
Bud burst is early, late August in New Zealand. Flowering usually commences in September and is early in relation to other cultivars. The variety is self-fertile. Fruit is harvested early in the blackcurrant harvest season in New Zealand, in early January. The main use of the fruit is juice processing and the variety is suitable for machine harvest. Fruit is typically taken direct from the field to the processing facility.
Pest and Disease Resistance
No pest and disease resistance was observed. The new variety was found to be susceptible to gall mite ( Cecidophyopsis ribis ).
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A new and distinct variety of blackcurrant named ‘Blackadder’, botanically identified as Ribes nigrum is described. The new variety is distinguished from others by its early season bud burst, flowering and harvest. Its bush has an upright habit suitable for machine harvesting. Yields are high and the fruit has high anthocyanin levels and moderate ascorbic acid levels.
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FIELD OF THE INVENTION
[0001] The present invention relates to novel solid forms of fluoroquinolones, particularly to complex co-crystals and solvates, hydrates and polymorphs thereof, and their use in the preparation of a pharmaceutical composition useful as an antibiotic.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to novel solid forms (NSF) of fluoroquinolones, particularly to complex crystals, which have a consistent quality and improved physicochemical properties such as chemical and physical stability and higher dissolution rate.
[0003] The present invention describes co-crystals obtained from a fluoroquinolone salt and a neutral co-former, where both are solid at room temperature. For the present case we designate them as “complex co-crystals”, which have improved physicochemical properties, such as increased solubility, dissolution rate, enhanced flow properties and stability.
[0004] For the present invention, the NSF are also called co-crystals, obtained by technical experimentation. The co-crystals are chemical entities with different physicochemical properties as compared to the salts or polymorphs of the active agent on which they are based on, because of the nature of intermolecular interactions between the molecule of matter and a second solid constituent, the latter hereinafter designated as coformer.
[0005] A co-crystal is a multicomponent crystal, in which the starting components are solid under ambient conditions and in their pure form, and in which two or more components of the co-crystal form aggregates that are characterized by being bound together by interactions—such as Van der Waals forces, π-stacking, hydrogen bonding or electrostatic interactions, but without forming covalent bonds. By employing crystal engineering techniques a new substance can be obtained with modified physicochemical properties that differ from the existing polymorphs, salts, hydrates and/or solvates. The exploration adjustable parameters are better, so the physical properties of the active principle with clinical relevance can be optimized.
[0006] The pharmaceutical co-crystals are co-crystals containing at least one therapeutic molecule and a pharmaceutically acceptable co-former. In these substances, such components coexist in a well-defined stoichiometric ratio between the active ingredient and the co-former. Co-crystals in solid form tend to be more stable than the existing solvates or hydrates.
[0007] Fluoroquinolones are a group of synthetic antimicrobial agents. Structurally, they consist of a heterocyclic derivative of 4-quinolone with a fluorine atom attached to C6, as shown in Scheme I, and several substituent groups R1, R2, R3 and R4 that may be, among others, hydrogen, alkyl chains, alkoxy groups, amino, cyclopropoxy and/or heteroaromatic rings such as piperazine, cinnoline and piridopiridine at position 7 (R2).
[0000]
[0000] R1 may be H, an alkyl chain or a carboxyl;
R2 may be a heterocyclic amine such as pyridine, piperazine, piperidine, pirrolpiridine, pirrolpiperazine, cinnoline, morpholine, pyrrole, pyrrolidone;
R3 may be an H, an alkyl chain or an alkoxy;
R4 may be an H, an alkyl chain, carboxyl, cyclo propyl, indole ethanol, an alkyl chain or a linear carboxyl or attached to an alkoxy, which may or may not form a ring with R3.
[0008] The most representative fluoroquinolones are: ofloxacin, levofloxacin (S(−)enantiomer ofloxacin), enoxacin and pefloxacin, lomefloxacin, norfloxacin, ciprofloxacin, grepafloxacin (ciprofloxacin analog), sparfloxacin, tosufloxacino, gatifloxacin, trovafloxacin, clinafloxacin, sitafloxacin, moxifloxacin and gemifloxacin. The present invention develops a method of obtaining co-crystals or other solid forms starting from the salts of some of these fluoroquinolones, such as moxifloxacin, levofloxacin or ciprofloxacin.
[0009] Moxifloxacin is a fourth-generation antibiotic of the fluoroquinolone group. Its structural formula is shown in Scheme II.
[0000]
[0010] In commercial pharmaceutical preparations moxifloxacin is in the form of hydrochloride salt, which is water soluble, has an absolute bioavailability of 86 to 92%, has a plasmatic protein binding of from 30% to 50%, has a half-life between 11.5 and 15.6 hours (single dose) and its excretion is via the liver [Zhanel G G et al. “A critical review of the fluoroquinolones”, Drugs, 62 (1), p. 13-59 (2002)]. This fluoroquinolone is active against gram-positive and gram-negative bacteria. It is administered orally or parenterally in a single dose of 400 mg once daily and has a good pharmacokinetic profile. Approximately 45% of an oral or intravenous dose of moxifloxacin is excreted as the unchanged drug (˜20% in urine and ˜25% in feces) [Rodvold K A et al. “Pharmacokinetics and pharmacodynamics of fluoroquinolones”, Pharmacotherapy, 21 (10 Pt 2), pp. 233S-252S (2001)].
[0011] Levofloxacin is a broad spectrum antibiotic which consists of the S(−) isomer of ofloxacin (Scheme III). Levofloxacin hemihydrate is used in commercial pharmaceutical compositions. It has a bioavailability of 99%, it has a plasmatic protein binding of from 24% to 38%, it has a half-life between 6 and 8 hours (single dose), it is administered at a dose of from 250 mg to 500 mg once or twice a day and is excreted via urine. [Pharmaceutical Press. Martindale: The complete Drug Reference. Levofloxacin. 2011. Accessed http://www.medicinescomplete.com. Apr. 12, 2011].
[0000]
[0012] Ciprofloxacin is a broad spectrum antibiotic that belongs to the family of antibiotics called fluoroquinolones, and its chemical formula is shown in Scheme IV. It is effective against gram-positive and gram-negative bacteria, it functions by inhibiting the DNA gyrase, a type II topoisomerase which is an enzyme required to separate the replicated DNA, inhibiting cellular division. Pharmaceutical compositions employ ciprofloxacin hydrochloride, a salt which is soluble in water and alcohol. In a 2.5% water solution it has a pH of from 3.5 to 4.5. It must be protected from light. Ciprofloxacin is rapidly and well absorbed from the gastrointestinal tract. The oral bioavailability is from 70% to 80%, the absorption of ciprofloxacin tablets may be delayed by the presence of food, but not substantially affected as a whole; it has a plasma protein binding of from 20% to 40%, it has a half-life of from 3 to 5 hours (single dose) and is excreted through kidney route. [Pharmaceutical Press. Martindale: The complete Drug Reference. Ciprofloxacin. 2011. Accessed http://www.medicinescomplete.com. Apr. 12, 2011].
[0000]
Adverse Effects
[0013] In general, fluoroquinolones are well tolerated, however, the most common side effects are: effects on the articular growth, erosion of the cartilage in growth, especially in weight-bearing joints. For this reason fluoroquinolones should not be administered to children and adolescents under 18 years old. The most serious adverse effect is particularly of cardiologic type as the duration of the QT interval of the electrocardiogram might be affected. If this interval is abnormally prolonged, may generate arrhythmias.
[0000] Interactions with Other Medicaments
[0014] Fluoroquinolones enhance the effect of anticoagulants and may enhance the hypoglycemic effect of sulfonylureas. Furthermore, aluminum salts (including sucralfate), magnesium, calcium, iron and zinc, significantly reduce the bioavailability of fluoroquinolones by non-absorbable chelators formation.
BACKGROUND
[0015] Document WO2009/136408 (Institute of Life Sciences), describes the preparation of co-crystals from second generation quinolones, ciprofloxacin and norfloxacin, specifically in its basic form. The aforementioned document comprises co-crystals of ciprofloxacin with co-formers eugenol, ferulic acid, isoferulic acid, citric acid or tartaric acid. The norfloxacin co-crystal is presented with co-formers like eugenol, ferulic acid, isoferulic acid, caffeine, citric acid, glutamic acid, vanillin, phenylalanine or resveratrol.
[0016] The present invention, unlike the aforementioned co-crystals in WO2009/136408, comprises “complex” co-crystals which are obtained from salts of a fluoroquinolone such as moxifloxacin or ciprofloxacin or levofloxacin, and which are not in their neutral form. The co-crystals of the present invention are obtained with co-formers of the kind of glycolic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, DL-malic acid, tartaric acid, cathecol, resorcinol, 4-aminobenzoic acid and 4-hydroxybenzamide. Such co-formers include one or more hydroxyl groups and/or carboxylic acid(s) that form an aggregate with fluoroquinolone hydrochloride, which may be selected without limitation from moxifloxacin, ciprofloxacin or levofloxacin.
[0017] Document WO2004091619 discloses a process for obtaining the crystalline form III of moxifloxacin hydrochloride or monohydrate. Said compound is obtained by a process of azeotropic reflux of moxifloxacin monohydrochloride, in a selection of organic solvents with subsequent alcohol washes for its purification and separation. The obtained crystalline form III is stable and can be used in the manufacture of a solid pharmaceutical composition for use as an antibiotic. Unlike document WO2004091619, the present invention comprises co-crystals of moxifloxacin hydrochloride; these co-crystals have better physicochemical properties, or process properties, such as improved solubility, dissolution rate, bioavailability, stability and/or flow properties.
[0018] Document WO2005089375 discloses a process for obtaining co-crystals of API through ultrasound and crystallization. For obtaining such co-crystals it is necessary to prepare the components which will form the co-crystal, which are prepared separately in either solutions or emulsions, on one hand the active ingredient and on the other the co-former; mixtures are saturated in a solvent or solvent mixture, then the preparations are combined in at least one environment having a temperature of 1° C. and are subjected to ultrasound, which will eventually form co-crystals.
[0019] Unlike this process, the present invention is specific for obtaining co-crystals of fluoroquinolones mainly by the method of crystallization from solution using an excess of co-former, or by the methods of solid phase transformation (slurry) and/or grinding, with the use of minimum solvent amount and environmental conditions that do not involve taking it to freezing point. This obtention process lowers the equipment operation costs to obtain co-crystals and has a minimum impact on the environment, because basically no organic solvents are used.
JUSTIFICATION OF THE INVENTION
[0020] The rational use of antibiotics aims to get the most benefit for people who use them, limiting the development of resistant organisms and minimizing economic costs. Hence the importance of relying on a drug that produces the same therapeutic effect with lower doses and thereby decreasing side effects, achieving greater adherence to the treatment and consequently reducing the creation of resistant strains.
[0021] Moxifloxacin, levofloxacin and ciprofloxacin are broad spectrum antibiotics of delicate use, so that there is need of having complex co-crystals that increase the activity and allow for a lower dose to the patient.
[0022] In the prior art there is no information about the formation of complex co-crystals of moxifloxacin, ciprofloxacin or levofloxacin salts. During the process of obtaining co-crystals one may conceive of a lot of combinations with potential co-formers. However, not all combinations produce a co-crystal or a solid stable form. In addition, the co-crystals that unexpectedly may be obtained, may or may not have better rheological properties, of solubility or physicochemical properties.
[0023] Although there is a good understanding of the physicochemical of the components of a co-crystal, it is practically impossible their elucidation a priori, as the interactions that determine their structure are relatively weak and the number of degrees of freedom of the optimization problem is immeasurable. In the case of salts, their formation is not as difficult as that of the co-crystals, however, there is not a reliable way to determine a priori whether their physicochemical characteristics such as solubility, chemical and physical stability will be suitable for a pharmaceutical composition. For these reasons, the new solid forms disclosed in this document are not obvious to a person skilled in the art.
SUMMARY OF THE INVENTION
[0024] The present invention provides several undisclosed compounds of moxifloxacin, ciprofloxacin and other fluoroquinolones, which are identified as complex co-crystals formed from a salt of the antibiotic and a neutral co-former. These co-crystals have enhanced physicochemical and biopharmaceutical properties, which confer advantages for the preparation of pharmaceutical compositions, such as improved bioavailability, improved solubility, dissolution rate, enhanced processability of the drug and/or enhanced pharmacokinetic properties, and consequently, fewer side effects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIGS. 1-22 illustrate the results of the characterization of the moxifloxacin co-crystals obtained in the present invention.
[0026] FIGS. 23-32 illustrate the results of the characterization of the ciprofloxacin co-crystals obtained in the present invention.
[0027] FIG. 1 . X-ray powder diffraction pattern of the co-crystal of Moxifloxacin HCl with 4-hydroxybenzoic acid.
[0028] FIG. 2 . DSC-TGA thermal analysis of the co-crystal of Moxifloxacin HCl with 4-hydroxybenzoic acid.
[0029] FIG. 3 . TF-Infrared spectrum of the co-crystal of Moxifloxacin HCl with 4-hydroxybenzoic acid.
[0030] FIG. 4 . CP-MAS 13 C NMR spectrum of a) moxifloxacin, b) 1 to 1 physical mixture of moxifloxacin and 4-hydroxybenzoic acid, and c) moxifloxacin co-crystal with 4-hydroxybenzoic acid.
[0031] FIG. 5 . Crystalline structure of the co-crystal of moxifloxacin HCl with 4-hydroxybenzoic acid.
[0032] FIG. 6A . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with anhydrous 2,5-dihydroxybenzoic acid.
[0033] FIG. 6B . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with hydrated 2,5-dihydroxybenzoic acid.
[0034] FIG. 6C . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with 2,5-dihydroxybenzoic acid solvate MeOH.
[0035] FIG. 7 . DSC-TGA thermal analysis of the co-crystal of moxifloxacin HCl with 2,5-dihydroxybenzoic acid.
[0036] FIG. 8 . TF-Infrared spectrum of the co-crystal of moxifloxacin HCl with 2,5-dihydroxybenzoic acid.
[0037] FIG. 9 . Crystalline structure of the co-crystal with moxifloxacin HCl co-crystal and 2,5-dihydroxybenzoic acid.
[0038] FIG. 10 . X-ray powder diffraction pattern of the co-crystal with moxifloxacin HCl and 3-hydroxybenzoic acid.
[0039] FIG. 11 . X-ray powder diffraction pattern of the co-crystal with moxifloxacin HCl and 2,4-dihydroxybenzoic acid.
[0040] FIG. 12A . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with 3,4-dihydroxybenzoic acid anhydride.
[0041] FIG. 12B . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with 3,4-dihydroxybenzoic acid sesquihydrate.
[0042] FIG. 13 . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl monohydrate with 3,5-dihydroxybenzoic acid.
[0043] FIG. 14 . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with gallic acid.
[0044] FIG. 15 . X-ray powder diffraction pattern of the co-crystal of Moxifloxacin HCl with cathecol.
[0045] FIG. 16 . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with resorcinol.
[0046] FIG. 17 . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with glycolic acid.
[0047] FIG. 18 . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with DL-malic acid.
[0048] FIG. 19 . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with D-tartaric acid.
[0049] FIG. 20 . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with 4-hydroxybenzamide.
[0050] FIG. 21 . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with 4-aminobenzoic acid.
[0051] FIG. 22 . X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with 4-hydroxybenzyl alcohol.
[0052] FIG. 23 . X-ray powder diffraction pattern of the co-crystal of ciprofloxacin HCl with 4-hydroxybenzoic acid.
[0053] FIG. 24 . X-ray powder diffraction pattern of the co-crystal of ciprofloxacin HCl with 3-hydroxybenzoic acid.
[0054] FIG. 25 . X-ray powder diffraction pattern of the co-crystal of ciprofloxacin HCl with 2,3-dihydroxybenzoic acid.
[0055] FIG. 26 . X-ray powder diffraction pattern of the co-crystal of ciprofloxacin HCl with 2,4-dihydroxybenzoic acid.
[0056] FIG. 27 . X-ray powder diffraction pattern of the co-crystal of ciprofloxacin HCl with 2,5-dihydroxybenzoic acid.
[0057] FIG. 28 . X-ray powder diffraction pattern of the co-crystal of ciprofloxacin HCl co-crystal with 3,4-dihydroxybenzoic acid.
[0058] FIG. 29 . X-ray powder diffraction pattern of the co-crystal of ciprofloxacin HCl with 3,5-dihydroxybenzoic acid.
[0059] FIG. 30 . X-ray powder diffraction pattern of the co-crystal of ciprofloxacin HCl with cathecol.
[0060] FIG. 31 . X-ray powder diffraction pattern of the co-crystal of ciprofloxacin HCl with resorcinol.
[0061] FIG. 32 . X-ray powder diffraction pattern of the co-crystal of ciprofloxacin HCl with hydroquinone.
DETAILED DESCRIPTION OF THE INVENTION
[0062] One of the challenges faced by the development of the present invention was to obtain a stable compound of fluoroquinolone, with high purity, with physicochemical properties suitable for preparing a pharmaceutical composition and which improves the existing forms in terms of stability, solubility and/or dissolution rate. Due to the complexity of the interactions in a solid structure, the final structure and thus the properties of the new solid forms are impossible to predict theoretically, so that a number of experiments had to be carried out to find the compounds described herein.
[0063] The complex co-crystals of the present invention, in the preferred embodiment, are formed from fluoroquinolone-halide salt and neutral co-former, both being solids at room temperature. The NSF obtained from the combination of these solids, consist of an aggregate in which the components of the fluoroquinolone salt and the neutral co-former molecule interact through hydrogen bonding, Van der Waals or electrostatic interactions. The new solid form obtained in the present invention offer the advantage of generating solid active ingredients with improved physicochemical properties, such as improved solubility, stability or easy-flowing properties.
[0064] The present invention started from a fluoroquinolone salt which may be, for example, ciprofloxacin or moxifloxacin in its hydrochloride form.
[0065] Moxifloxacin hydrochloride was reacted with a variety of possible co-formers in the presence of solvents such as tetrahydrofuran (THF), methanol (MeOH), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), acetone, acetonitrile or water. In the preferred embodiment saturated solutions of the respective co-formers were prepared, to which small amounts of solid moxifloxacin hydrochloride were added under constant agitation. The added solid is dissolved and additions are interrupted due to the appearance of a new insoluble solid form in the dissolution medium. From these reactions several possible combinations among moxifloxacin, coformer and solvent were carried out. The product of these reactions was characterized by X-ray powder diffraction assay. This test showed that NSF were generated either as solvates, hydrates and co-crystals. From the results of these tests it was concluded that the formation of co-crystals is neither simple nor predictable. The new solid phases that form an aggregate with moxifloxacin hydrochloride can be obtained by several methods such as grinding, the solid phase transformation (slurry) and/or crystallization of saturated solutions.
[0066] In the present invention was carried out with the following co-formers, among others: aliphatic carboxylic acids, aromatic carboxylic acids, hydroxybenzoic aromatic acids, hydroxycarboxylic acids, polyols (aromatic polyols), benzamide derivative, benzyl alcohol, dextrins, amino acid derivatives, disaccharides, polysaccharides, monosaccharides and/or polyphenols such as gallic acid (known as gallates), flavones, cinnamic acid and its derivatives such as quercetin, catechin, epigallocatechin and/or resveratrol. In the early tests of the present invention new solid forms (NSF) were obtained, which were stable with co-formers such as glycolic acid, 3-hydroxybenzoic and 4-hydroxybenzoic acid. These NSF obtained correspond to compounds wherein the neutral co-former has a hydroxyl group and a carboxylic acid, some of them also contain a phenyl as part of their structure.
[0067] Additionally, and in order to define the structural diversity of the co-formers that generate co-crystals, other reactions were carried out, now with hydroxycarboxylic acids and aromatic and aliphatic dicarboxylic acids such as benzoic acid, phthalic, isophthalic, terephthalic, and trans-cinnamic, which did not generate a NSF as product. Other reactions were performed with aromatic monocarboxylic acids with two or three hydroxyl groups, such as vanillic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 3,4-dihydroxybenzoic, 3,5-dihydroxybenzoic acid and gallic acid. NSF were obtained with these co-formers, with the exception of vanillic acid.
[0068] In order to determine whether the replacement of a carboxylic acid instead an amide group in the 4-hydroxybenzoic acid and salicylic acid influenced the obtention of NSF, the corresponding benzamides (4-hydroxybenzamide and salicylamide) were examined. Also, 4-aminobenzoic acid and 4-hydroxybenzyl alcohol were tested. Similarly, analogs of nicotinamide and isonicotinamide were used, in which the amino group was replaced by the carboxylic group, generating the respective nicotinic and isonicotinic acids. Additionally, picolinic acid was included to complete the study on this type of compounds. The study also included the 2-hydroxynicotinic and cathecol, in order to explore the need of the phenyl group and the carboxylic acid in the structure of the co-formers. Resorcinol was used additionally as co-former, performing crystallization in saturated solution in methanol.
[0069] When working with aliphatic chain compounds, NSF were expected to be obtained by using dicarboxylic acids such as fumaric acid, adipic acid and pimelic acid, as stated by S. L. Childs et. al. [J. Am Chem Soc 2004, 126, pp. 13335]. As a result of working with aliphatic compounds, NSF were obtained with glycolic acid but not with the dicarboxylic acids. Other aliphatic carboxylic acids were tested, expecting for NSF formation, however, the novel forms were neither obtained with lactic acid nor glycine. For aliphatic polyols xylitol and L-ascorbic acid, in both DMSO and DMF, NSF were not obtained. NSF were obtained with malic acid and D-tartaric acid, again reflecting that the formation of NSF is not predictable.
[0070] Likewise and in order to determine the NSF formation with other molecules containing other types of donors for hydrogen bonding and aside from terminal carboxylic and hydroxyl groups, amino acids such as L-aspartic acid and L-glutamine were tested, as well as polyols such as cathecol, xylitol and ascorbic acid. The result was the formation of NSF only with cathecol, but not with xylitol or ascorbic acid.
[0071] Based on the results obtained for moxifloxacin hydrochloride, the ciprofloxacin hydrochloride salt was tested, and in this case it was reacted with a limited range of neutral co-formers, specifically those containing aromatic hydroxycarboxylic groups and aromatic diols in the presence of solvents such as tetrahydrofuran (THF), methanol (MeOH), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), acetone, acetonitrile or water. In the preferred embodiment NSF were obtained in combination with the co-formers 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, or 2,4-dihydroxybenzoic acid. Within this group NSF were not obtained when using 2-hydroxybenzoic acid or 2,6-dihydroxybenzoic in combination with ciprofloxacin hydrochloride. Additionally, NSF were generated from the combination with cathecol, resorcinol or hydroquinone.
Results of the Crystallization of Saturated Solutions for Obtaining NSF
[0072] Crystallization experiments with aromatic carboxylic acids, such as phthalic acid and terephthalic acid in MeOH and DMSO respectively, showed by means of the X-ray powder diffraction analysis that in both cases the solid obtained by the method of crystallization from saturated solutions corresponds exactly to moxifloxacin HCl, which means that no NSF was generated. Similar results were obtained for the trans-cinnamic acid, in which case the reactions were carried out with MeOH and DMSO.
[0073] Crystallization experiments with nicotinic acid, isonicotinic, picolinic acid and 2-hydroxynicotinic acid showed diffraction patterns similar to moxifloxacin HCl and its corresponding hidrosolvate. These obtained results ruled out the formation of NSF by the crystallization of the solutions with these coformers. These tests demonstrate that the crystallization reactions to form co-crystals are impossible to predict.
[0074] Crystallization processes performed with hydroxybenzoic acids gave different results, for example for crystallization of saturated solutions of 4-hydroxybenzoic acid in methanol resulted in a new phase, as shown in FIG. 1 . Similarly using methanol or THF, NSF were obtained with the co-formers 3-hydroxybenzoic acid ( FIG. 10 ), 2,4-dihydroxybenzoic acid ( FIG. 11 ), 2,5-dihydroxybenzoic acid ( FIGS. 6A , 6 B and 6 C), 3,4-hydroxybenzoic acid ( FIGS. 12A and 12B ) and 3,5-hydroxybenzoic acid ( FIG. 13 ).
[0075] From the reactions between moxifloxacin HCl and 4-hydroxybenzoic acid, the formation of stable co-crystals was obtained. This was confirmed by X-ray Powder Diffraction (XRD) analysis, differential scanning calorimetry/thermogravimetric analysis (DSC/TGA), and infrared spectrum (FT-IR), as illustrated in the annexed figures. FIG. 3 shows the X-ray powder diffraction pattern of the co-crystal of moxifloxacin HCl with 4-hydroxybenzoic acid. FIG. 2 shows a DSC-TGA thermal analysis of the co-crystal of moxifloxacin HCl with 4-hydroxybenzoic acid. FIG. 4 shows the nuclear magnetic resonance spectrum (NMR) of the 13 C core in solid-state ( 13 C CP-MAS NMR) of: a) moxifloxacin NSF; b) the physical mixture in the molar ratio 1 to 1 of moxifloxacin HCl/4-hydroxybenzoic acid; and c) moxifloxacin NSF with 4-hydroxybenzoic acid.
[0076] FIG. 5 shows the asymmetric unit of the crystalline structure of moxifloxacin HCl co-crystal with 4-hydroxybenzoic acid, obtained by X-ray diffraction of the monocrystal.
[0077] FIGS. 7 , 8 and 9 show the DSC-TGA thermal analysis, the TF-IR infrared spectrum and the asymmetric unit of the crystalline structure of Moxifloxacin HCl co-crystal with 2,5-dihydroxybenzoic acid.
[0078] In the crystallization of saturated solutions in THF in the case of gallic acid, the diffraction pattern corresponds to the one of moxifloxacin HCl, whereas for the 3,5-dihydroxybenzoic acid a NSF with a high degree of amorphicity was obtained. When the crystallization of saturated solutions was carried out in methanol, the powder diffraction pattern obtained showed an NSF either for both gallic acid ( FIG. 14 ) and 3,5-dihydroxybenzoic acid ( FIG. 13 ). Resorcinol also generated a co-crystal ( FIG. 16 ), as well as glycolic acid ( FIG. 17 ), DL-malic acid ( FIG. 18 ) and D-tartaric acid ( FIG. 19 ).
[0079] Crystallizations with aromatic hydroxibenzamides also showed positive results. The X-ray powder diffraction pattern analysis corresponding to 4-hydroxybenzamide in THF shows the formation of a new phase ( FIG. 20 ). Crystallization of saturated solutions of 4-aminobenzoic acid in methanol also generated a co-crystal ( FIG. 21 ), as well as with 4-hydroxybenzyl alcohol ( FIG. 22 ).
[0080] Crystallizations between ciprofloxacin HCl and 4-hydroxybenzoic acid resulted in stable NSF, characterized by an X-ray diffraction pattern different to the one of the starting materials ( FIG. 23 ). When employing combinations with other hydroxycarboxylic acids or aromatic polyols, NSF were generated. For example, NSF were obtained from ciprofloxacin hydrochloride in combination with the co-formers 3-hydroxybenzoic acid ( FIG. 24 ), 2,3-dihydroxybenzoic acid ( FIG. 25 ), 2,4-dihydroxybenzoic acid ( FIG. 26 ), 2,5-dihydroxybenzoic acid ( FIG. 27 ), 3,4-dihydroxybenzoic acid ( FIG. 28 ), 3,5-dihydroxybenzoic acid ( FIG. 29 ), cathecol ( FIG. 30 ), resorcinol ( FIG. 31 ) or hydroquinone ( FIG. 32 ).
New Solid Phases Obtained (NSP)
[0081] In the preferred embodiment of the present invention, as a result of experimentation NSF of moxifloxacin and ciprofloxacin were obtained. Some examples are shown hereinbelow.
[0082] The combination of the moxifloxacin salt with a chemical compound of aliphatic hydroxycarboxylic acids such as glycolic acid, D-tartaric acid or malic acid, among others.
[0083] The combination of the moxifloxacin salt with a chemical compound of derivatives of hydroxycarboxylic acids and aromatic analogs such as 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, 2,4-dihydroxybenzoic acid, 4-hydroxybenzamide, 4-aminobenzoic acid and others.
[0084] The combination of the moxifloxacin salt with a chemical compound of the aromatic polyol kind, such as cathecol, resorcinol or 4-hydroxybenzyl alcohol, among others.
[0085] The combination of the moxifloxacin salt with a chemical compound of a derivative of hydroxycarboxylic acids and aromatic analogues such as 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid 2,4-dihydroxybenzoic acid, 2,3-dihydroxybenzoic among others.
[0086] The combination of the moxifloxacin salt with a chemical compound of the aromatic polyol kind, such as cathecol, resorcinol or hydroquinone, among others.
[0087] The ciprofloxacin and moxifloxacin NSF obtention process can additionally start from a salt different from the hydrochloride salt, where the chlorine can be substituted by another halogen. The selected moxifloxacin salt is combined with any of the aforementioned co-formers.
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The invention relates to novel solid forms of fluoroquinolones, in particular to complex co-crystals and to solvates, hydrates and polymorphs thereof. These substances can be used to prepare a pharmaceutical composition containing same as an active ingredient, which can be used as an antibiotic. The compounds have a storage stability that is constant and above that of the salts or hydrates thereof.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/370,588, filed on Feb. 12, 2009, entitled “ENHANCED TELEPHONY COMPUTER USER INTERFACE ALLOWING USER INTERACTION AND CONTROL OF A TELEPHONE USING A PERSONAL COMPUTER,” which is a divisional of U.S. patent application Ser. No. 10/445,395, filed on May 20, 2003, now abandoned. This case is also related to U.S. patent application Ser. No. 12/370,579 filed on Feb. 12, 2009, entitled “ENHANCED TELEPHONY COMPUTER USER INTERFACE ALLOWING USER INTERACTION AND CONTROL OF A TELEPHONE USING A PERSONAL COMPUTER”, which is also a divisional of U.S. patent application Ser. No. 10/445,395.
The entirety of each of the foregoing applications is incorporated herein by reference.
TECHNICAL FIELD
This invention relates in general to integrated computer telephony and in particular to an enhanced telephony computer user interface that allows a user to control and manage a telephone from a personal computer while seamlessly integrating telephone and personal computer features to provide a rich user-controlled telephone management system and method.
BACKGROUND OF THE INVENTION
Personal computers and telephones are two indispensable devices in modern life. Personal computers (PCs) and telephones both provide the ability to communicate instantaneously with others virtually anywhere in the world. In addition, PCs have revolutionized modern society with their ability to process information and data and to provide a user interaction with this information and data. PCs also have the capability to control other devices. This capability, for example, allows a user to remotely control the peripheral device through a user interface, often graphical user interfaces. Even though the PC and telephone often exist in the same room, however, there currently exist few attempts to provide a useful integration of the two devices that takes full advantage of their strengths.
There have been many attempts at integrating the telephone with the personal computer, but with little market success. These failures are due to in part to problems with the product design including, for example, poor user interface design, the need for expensive additional hardware, and unrealistic user expectations. In addition, these products do not allow a user to access a telephone from a location different from the physical location of the telephone.
One product example is the Microsoft® Phone, which was included in Microsoft Windows® 95. Microsoft® Phone is a software-only speakerphone and answering machine that allowed a user to use their computer as a speakerphone. The Microsoft® Phone, however, required that the computer always be on (which was an unrealistic expectation in the Windows® 95 era) and was an expensive added feature to Windows® 95 because it required additional hardware. Moreover, the Microsoft® Phone has limited functionality.
Another product example that attempts to integrate the telephone with the personal computer is the IBM® Realphone. The IBM® Realphone is a telephone-dialing program that is modeled after a standard business telephone. The Realphone interface is a picture of the business telephone on the display. One problem, however, is that the advantageous synergies of the telephone and the computer are not merged. For example, the interface requires a user to use an input device (such as a mouse) to press the telephone keypad on the screen and dial a desired telephone number, as one would dial a real telephone. However, this type of interface is difficult, laborious and time-consuming for a user.
There has been more product success with integrating the telephone and the computer in the call center environment. For example, the call center environment (such as customer support and telemarketing centers) often includes software applications that provide telephone information such as a phone queue display (the order of callers in a queue), a display of how many calls are waiting, and the ability to route calls to representatives. These software applications are designed for the customer service audience, however, and there is little or no attempt to meet the need of the private user or provide a user-friendly integration of the physical telephone and the software interface. For the call center audience, a priority is to increasing call throughput and quickly assigning calls in the queue, while the user experience is not. Moreover, telephony applications for the call center environment lack functionality and control features needed by an end-user that are critical for a high-quality user experience.
Therefore, there exists a need for a user interface allowing a user to seamlessly interact with a telephone using a personal computer. The user interface needed should provide a user with a rich variety of functionality and take advantage of the processing power of the computer to enhance a telephone's capabilities. Moreover, the user interface needed should provide a tight coupling between the personal computer and the telephone such that a user is unaware of any division between the two.
SUMMARY OF THE INVENTION
The invention disclosed herein includes a computer user interface that integrates features of a personal computer (PC) and a telephone into a coherent enhanced telephony (ET) user interface. The ET user interface resides on a personal computer and facilitates user control of all telephone functions using the processing power of a personal computer. More than this, however, the ET user interface includes features that are only made possible by the use of a PC merged into a telecommunications environment.
The ET user interface overcomes problems with prior attempts to integrate the PC and the telephone. Specifically, the user is provided with a rich variety of functionality that leverages the fact that the PC has considerably more processing power and greater access to variety of data than the ordinary telephone. This processing power and data access is used to the user's advantage as the telephone's capabilities and functionality are greatly expanded. Moreover, the ET user interface provides a tight coupling between the personal computer and the telephone such that a user is unaware of any division between the two. This seamless integration, along with enhanced functionality, greatly simplifies and improves the user experience.
The user can be at a different physical location from the telephone and still be able to control the telephone using the ET user interface. The only requirement is that the ET user interface and the telephone be network connected. Thus, the user, as long as he has access to the network, can control the telephone from virtually anywhere.
The ET user interface is designed to operate in both a telecommunications and computer environment, either in an enterprise or home setting. For example, in the typical enterprise setting, the enterprise owns the telephone equipment tied to the public telephone lines and employees have access to a corporate computer network. In another example, in the typical home setting the user has calendar and address book data on his PC and has access to a public telephone network.
The ET user interface is designed to control and manage a single telephone or multiple telephones, including cellular phones, cordless phones, and desk phone. Moreover, these phones can be located at different locations, such as a mobile phone, a home phone and a work phone. The ET user interface also allows the telephone to be used as an intercom and to provide wakeup calls and meeting reminders.
In general, the ET user interface includes a plurality of environments for the user to choose. These environments include a My Contacts environment, a communication preferences environment, and a Call History environment. Each of these environments contains certain available processes and features for controlling and managing telephones. The processes include actions and collaborations relevant to a contact, a telephone, or both. The features and processes are integrated with databases linked to the interface such that information about contacts (such as persons and entities) can be obtained from multiple sources and merged into a single accessible entry.
The ET user interface includes an environment region, a process region, and an activity region. In addition, the interface includes a call status region that keeps a user informed as to a status of controlled telephones. The My Contacts environment includes processes that allow the user to initiate, terminate and control both incoming and outgoing calls from the PC with a minimum of effort. A favorites feature give the user access to his most popular persons to call, based on a popularity criteria. A search feature allows a user to search linked databases (such as, for example, corporate and personal address books) for desired information. In addition, the search can be limited to a specific database, such as from the Outlook application running on the PC.
The My Contacts environment includes features to enhance placing a call. In particular, when a call is placed the user receives both visual and audio cues that keep the user informed of the progress of the call. Once in the call, a call window appears containing detailed information about the person at the other end of the line and links to previous information associated with that person. For example, any documents opened during previous conversations with the person or e-mails received from him are listed in the call window such that the user can retrieve them by clicking. An advanced call camp feature allows the ET user interface to notify the user when a person becomes available if the person was previously unavailable (such as when the person's line was initially busy). Moreover, the advanced call camp feature can be integrated with the person's calendar to provide the user with the best time to call the person.
The My Contacts environment includes call transfer and conference calling processes. The user can initiate a conference call while in a telephone conversation by merely clicking a button in the interface. Visual and audio cues, from both the PC and the telephone, are used to keep the user informed as to the progress of the establishment of the conference call. In addition, a synthetic voice can be used to automatically inform persons being called for the conference call to stand by until all persons have joined the call.
The user is notified of incoming calls both visually and audibly. In visual terms, an incoming call notification window appears on the user's desktop to signal an incoming call. If the telephone system includes caller identification, the caller's telephone number can be matched to detailed information about the caller from the linked databases. This information then is displayed in the window. The window can also include the calendar of the caller, so that the user can better decide whether to answer the call. In audio terms, rich ring tones available from sound files played on the PC can signal an incoming call. These sound files can be caller-specific, such that the user can identify from the ring tone who is calling. The incoming call notification window also includes a quick transfer button. This button enables the user to transfer an incoming call to the user's present location, such as the user's cell phone, when the user is away from the telephone being called.
Another incoming call feature is an unknown contact conversion feature. This feature converts unknown contacts into known contacts using a variety of sources. Thus, if an incoming call is received from an unknown caller (one who is not in the linked databases), then ET user interface obtains and provides as much information as it can find about the unknown caller in an attempt to determine the identity of the caller. By way of example, the unknown contact conversion feature can obtain the unknown caller's geographic location based on the area code of the caller. As another example, the feature can access public Internet sites to perform a search to find online the person associated with the telephone number. Alternatively, the user can provide a name for the unknown caller. Once the unknown caller's identity is determined, the information is saved in the linked databases such that the next time the caller calls his identity will be known.
Another feature of the My Contacts environment is a call forwarding feature that forwards incoming calls to other telephones under certain conditions. These conditions can be specified by the user. In the event that an incoming call is missed and the caller does not leave voice mail, the ET user interface can notify the user (such as by an e-mail notification) that the call has been missed. The missed call e-mail notification can also contain detailed information about the caller, including the caller's calendar so that the user can determine the best time to reach the caller.
While in a call, several features enable the user to have a richer user experience with the telephone and PC combination. A screen sharing feature allows the user to share the contents of the user's computer screen with a caller. A PC audio feature adjusts parameters on the PC based on telephone usage. For example, if the user is listening to a sound file on the PC and receives an incoming call, the sound on the PC is automatically muted or slowly lowered and the sound file is paused. Upon termination of the call, the parameters are returned to their previous settings.
A notes feature allows a user to create call notes while in a call. The notes can have headers intelligently created to aid in indexing, searching and later lookup. The headers contain information about the notes and the call, such as the call time, subject, and parties involved in the call. The headers can be call-centric, which means they are associated with a specific call, or person-specific, which means they are associated with a particular person. Headers can be created by integrating information from the linked databases to the notes. For example, calendar information can be used to determine the purpose of the call, and based on this information headers generated for notes created during that time period.
The My Call History environment provides the user with access to a history of call activity. Items such as incoming call logs, outgoing call logs, missed calls, and so forth, can be recorded in the call history. From this information, the call history environment can provide a statistical summary of call usage. Moreover, the ET user interface provides the user with the capability to dial directly a telephone number in the call history list or statistical summary.
The communication preferences environment provides a user with a way to notify others of the user's contact preferences. Thus, if a user prefers to be contacted by e-mail, this information can be contained within the contact information for the user or relayed to others by means of a icon. In addition, the communication preferences environment allows a user to create groups containing persons or entities and assign group-specific rules. For example, these rules can be rules for call forwarding and assigning a specific ring tone to the group. Further, the rules can be based on the calendar of each of the group members. The ET user interface also provides the user with the ability to obtain and change settings remotely. For example, the user could be notified by e-mail of the current settings for the ET user interface and then change these settings by sending a return e-mail containing the new settings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be further understood by reference to the following description and attached drawings that illustrate aspects of the invention. Other features and advantages will be apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the present invention.
Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
FIG. 1 illustrates an example of a suitable computing system environment 200 in which the enhanced telephony (ET) user interface may reside.
FIG. 2A illustrates a first implementation of the ET user interface incorporated into the computing and telephone environments where a telephone is not connected directly to a computing device.
FIG. 2B illustrates a second implementation of the ET user interface incorporated into the computing and telephone environments where the telephone and the computing device are connected.
FIG. 3 is a general block diagram illustrating the different sources of information for the ET user interface shown in FIGS. 2A and B.
FIG. 4 illustrates a general overview of the ET user interface shown in FIGS. 2A , 2 B and 3 .
FIG. 5 illustrates the My Contacts environment of the ET user interface.
FIG. 6 illustrates the search feature tab contained in the My Contacts environment shown in FIG. 5 .
FIG. 7 illustrates the dialpad feature tab contained in the My Contacts environment shown in FIG. 5 .
FIG. 8 illustrates the ET user interface as an outgoing call is initiated by a user.
FIG. 9 illustrates the ET user interface during after the call initiated in FIG. 8 has been established.
FIG. 10 illustrates the ET user interface during an establishment of a conference call by a user.
FIG. 11 illustrates the ET user interface providing the user with a choice of contacts to conference in after the user request shown in FIG. 10 .
FIG. 12 illustrates the cues used by the ET user interface to update the user on the status of the conference call shown in FIGS. 10 and 11 .
FIG. 13 illustrates the ET user interface during a conference call that includes two callers.
FIG. 14 illustrates the ET user interface during an incoming call.
FIG. 15 illustrates the ET user interface during a quick transfer of the incoming call shown in FIG. 14 .
FIG. 16 illustrates an example of an e-mail notification sent by the ET user interface notifying a user of a missed call.
FIG. 17 illustrates an example of an e-mail notification for an unknown caller.
FIG. 18 illustrates an example of the Call History environment.
FIG. 19 illustrates the settings process in the communication preferences environment of the ET user interface.
DETAILED DESCRIPTION OF THE INVENTION
In the following description of the invention, reference is made to the accompanying drawings, which form a part thereof, and in which is shown by way of illustration a specific example whereby the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
I. Introduction
Despite the importance of the telephone and personal computer in most people's everyday lives, the two remain largely disconnected from each other. Although certain specialized applications exist that link the two devices for use in areas such as telemarketing and customer service centers, the application for personal use has remained essentially ignored. The enhanced telephony (ET) user interface telephone brings computer-telephony to the personal computer desktop to provide a user with a rich interactive experience that integrates computer and telephony features for general use.
II. Enhanced Telephony (ET) User Interface Environment
The ET user interface is designed to operate in a combined telecommunications and computer environment. In particular, the ET user interface resides on a computing device. Using the peripheral devices of the computing device, a user is able to obtain visual and audio information from the ET user interface about telephones in communication with the computing device. By way of example and not limitation, a peripheral devices such as a display device and speakers may be connected to the computing device such that the ET user interface informs the user about the telephones in an audible manner (via the speakers) and in a visual manner (via the display device).
The following discussion is intended to provide a brief, general description of a suitable computing environment in which the ET user interface may be implemented. FIG. 1 illustrates an example of a suitable computing system environment 100 in which the ET user interface may reside. The computing system environment 100 is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. Neither should the computing environment 100 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment 100 .
The ET user interface is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that may be suitable for use with the ET user interface include, but are not limited to, personal computers, server computers, hand-held, laptop or mobile computer or communications devices such as cell phones, PDAs, merged cell phones and PDAs, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like.
The ET user interface may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. The ET user interface may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices. With reference to FIG. 1 , an exemplary system for implementing the ET user interface includes a general-purpose computing device in the form of a computer 110 .
Components of the computer 110 may include, but are not limited to, a processing unit 120 , a system memory 130 , and a system bus 121 that couples various system components including the system memory to the processing unit 120 . The system bus 121 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus also known as Mezzanine bus.
The computer 110 typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by the computer 110 and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data.
Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computer 110 . Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media.
Note that the term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer readable media.
The system memory 130 includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) 131 and random access memory (RAM) 132 . A basic input/output system 133 (BIOS), containing the basic routines that help to transfer information between elements within the computer 110 , such as during start-up, is typically stored in ROM 131 . RAM 132 typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit 120 . By way of example, and not limitation, FIG. 1 illustrates operating system 134 , application programs 135 , other program modules 136 , and program data 137 .
The computer 110 may also include other removable/non-removable, volatile/nonvolatile computer storage media. By way of example only, FIG. 1 illustrates a hard disk drive 141 that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive 151 that reads from or writes to a removable, nonvolatile magnetic disk 152 , and an optical disk drive 155 that reads from or writes to a removable, nonvolatile optical disk 156 such as a CD ROM or other optical media.
Other removable/non-removable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The hard disk drive 141 is typically connected to the system bus 121 through a non-removable memory interface such as interface 140 , and magnetic disk drive 151 and optical disk drive 155 are typically connected to the system bus 121 by a removable memory interface, such as interface 150 .
The drives and their associated computer storage media discussed above and illustrated in FIG. 1 , provide storage of computer readable instructions, data structures, program modules and other data for the computer 110 . In FIG. 1 , for example, hard disk drive 141 is illustrated as storing operating system 144 , application programs 145 , other program modules 146 , and program data 147 . Note that these components can either be the same as or different from operating system 134 , application programs 135 , other program modules 136 , and program data 137 . Operating system 144 , application programs 145 , other program modules 146 , and program data 147 are given different numbers here to illustrate that, at a minimum, they are different copies. A user may enter commands and information into the computer 110 through input devices such as a keyboard 162 and pointing device 161 , commonly referred to as a mouse, trackball or touch pad.
Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, radio receiver, or a television or broadcast video receiver, or the like. These and other input devices are often connected to the processing unit 120 through a user input interface 160 that is coupled to the system bus 121 , but may be connected by other interface and bus structures, such as, for example, a parallel port, game port or a universal serial bus (USB). A monitor 191 or other type of display device is also connected to the system bus 121 via an interface, such as a video interface 190 . In addition to the monitor 191 , computers may also include other peripheral output devices such as speakers 197 and printer 196 , which may be connected through an output peripheral interface 195 .
The computer 110 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 180 . The remote computer 180 may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 110 , although only a memory storage device 181 has been illustrated in FIG. 1 . The logical connections depicted in FIG. 1 include a local area network (LAN) 171 and a wide area network (WAN) 173 , but may also include other networks. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.
When used in a LAN networking environment, the computer 110 is connected to the LAN 171 through a network interface or adapter 170 . When used in a WAN networking environment, the computer 110 typically includes a modem 172 or other means for establishing communications over the WAN 173 , such as the Internet. The modem 172 , which may be internal or external, may be connected to the system bus 121 via the user input interface 160 , or other appropriate mechanism. In a networked environment, program modules depicted relative to the computer 110 , or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation, FIG. 1 illustrates remote application programs 185 as residing on memory device 181 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.
The ET user interface also is designed to operate in a telecommunications environment. FIGS. 2A and B are general block diagrams illustrating two possible implementations of the computing and telephone environments. FIG. 2A illustrates a first implementation of the ET user interface incorporated into the computing and telephone environments where a telephone is not connected directly to a computing device.
In this first implementation, the ET user interface 200 resides on a user computing device 205 . It should be noted that the computer 110 in FIG. 1 is an example of the user computing device 205 . This user computing device 205 may be any computing device capable of running and displaying the ET user interface, such as a PDA, notebook computer, or desktop computer. The user computing device 205 is connected 210 to a network via a telephony server 215 . Once again, the computer 110 in FIG. 1 is an example of the telephony server 215 .
Residing on the telephony server 215 are Computer-Telephone Integration (CTI) applications 220 . CTI applications 220 are system that provide control of telephones and receive information about their use. In other words, the CTI applications 220 provide the ability to control a telephone and the awareness of what the telephone is doing (such as knowing when the telephone rings). In this first implementation, the CTI applications 220 reside on the telephony server 215 , while in a second implementation (described below) the CTI applications 220 reside on the user computing device 205 .
The telephony server 215 is connected 225 to a private branch exchange (PBX) 230 , typically belonging to an enterprise such as a corporation. The PBX 230 , which usually is located on a company's premises, provides a connection between a telephone 235 and public telephone lines. The PBX 230 may also be a central office exchange service (centrex), a type of PBX where switching occurs at a local telephone station instead of at the company premises. In this first implementation, the telephone 235 is not directly connected to the user computing device 205 . Instead, the telephone 235 is connected into the PBX 230 via a connection 240 . The PBX 230 is connected 245 to a certain number of outside lines on a public switched telephone network (PSTN) 250 . A user 255 , through the ET user interface 200 , interacts with the telephone 235 and the user computing device 205 .
FIG. 2B illustrates a second implementation of the ET user interface incorporated into the computing and telephone environments where the telephone and the computing device are connected. In this second implementation, the telephone 235 is directly connected to the user computing device 205 via a wireless or cable connection 260 . The CTI applications 220 reside on the user computing device 205 instead of the telephony server 215 . The user computing device 205 is either connected 265 to a PSTN (as in a home setting) or connected to a PBX (as in an enterprise setting) 270 . Moreover, the telephone is also connected 270 to either the PSTN or the PBX 270 . In both implementations shown in FIGS. 2A and B, the user can use a second computing device (not shown) to remotely connect to the user computing device 205 that is co-located with the telephone 235 . Then, user can access the ET user interface 200 from the second computing device to transfer incoming calls to another telephone (such as a cell phone) at the user's location.
The ET user interface 200 obtains information from a variety of sources. This information then is disseminated to the user 255 using peripheral devices connect to the user computing device 205 (personal computer, or PC for short). For example, visual information is displayed on a display device and audio information is relayed through speakers or headphones. In addition, the ET user interface 200 allows a user to interact with the information through input devices connected to the PC, such as a keyboard and a mouse. In addition, the telephone 235 itself is an input device, because the ET user interface 200 uses the CTI applications 220 for awareness of the user's 255 interaction with the telephone 235 .
FIG. 3 is a general block diagram illustrating the different sources of information for the ET user interface 200 . In general, the ET user interface 200 receives information 300 from a variety of possible sources. These sources include personal databases 310 , enterprise databases 320 , and public databases 330 . The personal databases 310 include application-specific databases (such as e-mail, Outlook, instant messenger, and calendar databases), the enterprise databases 320 include the hierarchy of the corporation, corporate addresses, calendar database, and picture databases, and the public databases 330 include public Internet sites and online telephone books. Depending on the nature of its contents, a database may reside on either the telephony server 215 , the user computing device 205 , or both. For example, personal address books and calendar information (from the personal databases 310 ) may reside on the user computing device 205 (such as a user's personal computer), while the corporate hierarchy (from the enterprise databases 320 ) may reside on the telephony server 215 . The information 300 available to the ET user interface will be discussed in detail below in the context of features of the invention.
The ET user interface 200 can derive contact information from the various sources mentioned above and merge them into a single contact. For example, contact information from the enterprise databases 320 , the personal databases 310 (such as an address book), and the public databases 330 can yield multiple telephone numbers and other contact information for a single contact. This means that several contact entries exist, even though each entry may be the same person or entity. The contact information integration feature incorporates alleviates duplication and merges all of contact information and entries into a single contact entry for display in the ET user interface 200 .
In some cases a question may arise as to whether multiple contacts are one in the same person or entity. For example, a contact may be in the corporate databases 320 under his full name but be listed in a user's Outlook address book (from the personal databases 310 ) under his nickname. In these cases, the user typically is queried as to whether the contact found is the same person desired and whether the user wants to overwrite a new phone number found (such as a new home phone number for a person when his old number is in one of the databases).
III. Enhanced Telephony (ET) User Interface Layout
The ET user interface 200 contains several key aspects that provide a user with a rich user telephony experience. Some of these key aspects include the ability to initiate a call in the ET user interface 200 (click to call) from virtually anywhere a contact name or telephone number appears. Anywhere a contact name (assuming the name can be associated with a telephone number in the linked databases) or telephone number appears in the ET user interface 200 , the user merely clicks on the contact name or number to initiate a telephone call. This greatly reduces the number of mouse clicks or keyboard strokes required to place a call. Moreover, this click-to-call capability is not limited to calling a telephone, but can also be expanded to other means of contacting a person, such as e-mail and instant messenger.
Another key aspect of the ET user interface 200 is the merging of calendar information (such as from a user's personal calendar) and the user's presence status. In general, the presence status is any information that helps in understanding the user's location at any given time, what the user is doing, and how a person can contact the user. By way of example, for a person, presence information includes a person's calendar, their instant messenger status, applications that are currently open on their computer screen, the time since the person last moved the mouse or touched the keyboard, their current physical location, whether they have their cell phone turned on, whether their desk phone is busy, and how many people are in their office. All or some of this presence information can be displayed in the ET user interface 200 . Thus, based on calendar information, a presence status of the user is made available to others such that others are aware of the best time and the best (or preferred) means of contacting the user. Other key aspects of the ET user interface 200 include the unique call notification features available when the user misses an incoming call, and the unique call routing features that intelligently route an incoming call based on a user's input or integrated calendar information.
The key aspects, processes and features of the ET user interface 200 may be implemented in a variety of ways. Moreover, the appearance of the interface 200 may vary drastically between implementations. For example, the arrangement of different regions may be different, the number of tabs in each regions may vary, and even the names of the environments, features and process may differ. However, it should be understood that even though the appearance of the interface 200 may differ between implementations, the key aspects, processes and features described herein are still within the scope of the invention described herein.
A general description of the layout of the ET user interface 200 will now be discussed. This is the layout that a user sees and interacts with when running the ET user interface 200 on a computing device. It should be noted that this is one implementation of the ET user interface 200 , and several other layouts are possible. In general, the ET user interface 200 is divided into regions. These regions will be discussed with reference to FIG. 4 . Subsequent sections of this paper then will provide a more detailed description of each of the features that may be included in each region.
FIG. 4 illustrates a general overview of the ET user interface 200 shown in FIGS. 2A , 2 B and 3 . In general, a information 300 is displayed to a user through the ET user interface 200 and functionality is provide such that the user can interact with the information 300 . Specifically, the ET user interface 200 includes a main window 400 that is a standard Microsoft®. Windows® window containing a title bar 410 . Below the title bar 410 is an environment region 420 containing buttons for selecting any number of environments. It should be noted that although four environment buttons are shown, more or less may be included in the environment region 420 . By selecting one of the environment buttons, the user causes the ET user interface 200 to display certain features, as described below.
Below the environment region 420 is a call status region 430 . The call status region 430 provides information about a status of each telephone in communication with the ET user interface 200 . For example, if the user in not in a call, the call status region 430 displays a message that states “Not in a Call”. A process region 440 also is include in the ET user interface 200 . The process region 440 displays the available processes and allows user selection of those processes. Next to the process region 440 is located an activity region 450 . The activity region 450 displays feature tabs 460 that correspond to features available in the environment selected by the user. The processes and features are discussed in detail below.
IV. Feature and Process Details of the ET User Interface
The details of the features and processes associated with the ET user interface 200 will now be discussed with respect to each of the environments.
“My Contacts” Environment
The My Contacts environment provides a user with an interactive means to manage calls and contacts. This includes incoming calls, outgoing calls, and provides control and management feature while in a call. FIG. 5 illustrates the My Contacts environment of the ET user interface. As can be seen in FIG. 5 , the user has clicked on the My Contact environment button 500 to display this environment. The other environments also are shown, namely, the “Bestcom” environment 505 , the “My Telephones” environment 510 , and the “My Call History” environment 515 .
The My Contacts environment 500 includes three main processes in the process region 440 . The Call Control process 520 provides a user with the initiate, terminate, and control both incoming and outgoing calls from the PC. The Person Details process 525 allows the user to obtain detailed information about a contact. As explained in detail below, this information may be obtained from a variety of sources and integrated into a single contact entry. The Collaborate process 530 provides the user with various ways to get in touch with a contact, including e-mail and instant messaging (IM). In addition, the Collaborate process 530 allows the user to access the screen sharing feature, where the user can share his screen with the caller.
The My Contacts environment 500 also includes five features tabs in the activity region 450 . Namely, the Favorites tab 535 , the Recently Called tab 540 , the Search tab 545 , the Outlook Contacts tab 550 , and the Dialpad tab 555 . The activity region 450 also includes a search box 560 that uses the search feature 545 to search for a contact. It should be noted that a variety of other tabs are possible, and tabs may be added or deleted according to a user's preferences or corporate policy. As shown in FIG. 5 , the Favorites tab 535 has been clicked, so that the activity region 450 also display entries 565 , 570 , 575 , 580 of favorite contacts. Note that each entry 565 , 570 , 575 , 580 contains a variety of information about the contact. A key feature of the ET user interface 200 is that rich information is available for person or entity associated with a telephone number. In other words, more than just a list of telephone numbers is shown for each entry 565 , 570 , 575 , 580 .
Contact Information
Referring to FIG. 5 , in the activity region 450 is shown a list of favorite telephone numbers of the user. Note that each entry 565 , 570 , 575 , 580 can have an associated picture (if available), name, title, telephone number, and office location. The picture may be obtained from the corporate database, the user may specify the picture, or the contact can supply the picture. It should be noted that although a photograph is shown in FIG. 5 , the picture may be any of graphic or textual material. For example, if the contact is an entity (such as a department of the corporation), the picture may display the department logo. The contact information also includes other means of reaching the contact, such as a home and cellular telephone number and an e-mail address.
The contact information may also contain a presence status in addition to or in place of a picture. The presence status is any type of indicator that communicates to the user a status of the contact. For example, the presence status indicator may be a “happy face” graphic that is shown in color when the contact is connected to the corporate network or sitting at her computer but is grayed-out when she is not connected or away from her computer. Similar to instant messaging (IM) services, the presence status provides the user with additional information about the contact. If the user is on the telephone, the ET user interface 200 knows this and sets the user's presence status to “on the phone”. The ET user interface allows combined PC/IM user experience by using presence status and by providing IM contact information.
The presence status can have different levels depending on the relationship between the user and the contact. For example, if the contact is the user's supervisor, then richer presence information may be available to the user than would otherwise be available to others in the company. These levels may be set either explicitly by the user and the contact, or implicitly based on corporate policies.
Contact information may also include access to the contact's calendar. Of course, the contact would first have to provide consent to make his calendar available, either to everyone or to specific individuals of his choosing. The contact's calendar is loaded into the ET user interface 200 such that the user can determine the contact's location at a specific time or day. By way of example, assume that the user is trying to call a contact. By bringing up the contact in the ET user interface 200 and viewing his calendar, the user can determine when the contact is available and the best time to call.
The calendar feature can also be linked to the presence status to provide additional information about the contact. For example, if the presence status indicator communicates that the contact is away from her computer, the user can consult the contact's calendar and determine whether the contact is scheduled to be in a meeting or on the telephone.
The contact information includes a map feature that provides a map to the contact's office location. The map may be accessed through a link to the corporate database or an Internet connection. Through the ET user interface 200 , the user is able to enter his location and have the map feature provide directions to the contact's office. These direction may be graphical, textual, or both, depending on the user's preference.
Outgoing Call Features
As shown in FIG. 5 , the tabs in the activity region include a “Favorites” tab 535 , a “Recently Called” tab 540 , a “Search” tab 545 , an “Outlook Contacts” tab 550 , and a “Dialpad” tab 555 . It should be noted that other tabs are possible, and these tabs are only exemplary examples used in this implementation. Each of these tabs will now be discussed in the context of a user performing outgoing calling.
“Favorites” Tab
The Favorites feature tab 535 is used to access a favorites list tailored specifically for a user. When the user clicks the Favorites tab 535 , the favorites list (or a portion therefore) is shown in the activity region 450 of the ET user interface 200 . In general, the favorites list is a list of the user's favorite or most popular telephone numbers to call. The favorites list allows a user to quickly and easily call frequently-called contacts (similar to an enhanced speed dial). The popularity of the telephone number can be based on a number of criteria. By way of example, the criteria may include the user's calling frequency of the telephone number, how recently a number was called, a relationship between owner of the telephone number and the user (such as higher popularity to a user's boss and spouse), and a user's explicit instructions. Based on this popularity criteria, the user or the system can add or remove telephone numbers from the favorites list.
The favorites list can be generated or populated in a number of ways, both automatically and manually. For example, the user can manually construct his favorites list from his personal databases 310 , from the enterprise databases 320 , from the public databases 330 , or all of the above. The favorites list may populated with the other persons in the user's department, group or team along with the user's supervisors to whom he reports. The user can add still more favorites as he desires.
The favorites list may also be populated automatically. This automatic population of the favorites list can be performed by an analysis of virtually any database to which the user has access. For example, the favorites list may be populated using the user's e-mail database. In this situation, the ET user interface 200 obtains data about who the user sends e-mails to, receives e-mails from, or both and constructs a list. The top n numbers on the list then are used to populate the favorites list. The number n may be selected by the user (through the ET user interface) or selected automatically. As another example, the ET user interface 200 can have access to a list of calls recently made the user. Once again, the top n numbers can be used to populate the favorites list. It should be noted that the favorites list can be populated from a single list or database or multiple lists or databases.
Another type of automatic population (or pre-population) occurs at startup. At startup, the user typically will not have a list of favorites and will need to populate the favorites list. The ET user interface 200 includes an automatic customization feature that helps a user add telephone numbers to the favorites list. As described above, this automatic customization feature at startup initially populates the favorites list by an analysis of a database containing telephone numbers, explicit user input, or both. By way of example, in the enterprise setting the favorites list may be pre-populated at start up based on the corporate organizational structure available from the enterprise databases 320 . For example, the user's favorites list may include members of his department including his immediate supervisor. Once the favorites list has been populated using the automatic customization feature, the favorites list can be revised and changed either automatically or manually as desired, as described above.
“Recently Called” Tab
A Recently Called feature tab 540 also is included in the ET user interface 200 . This tab 540 allows a user to access a list of recently-called telephone numbers made by the user. The top n recently called telephone numbers can be used to populate the recently called list. It should be noted that the recently called list can be populated from a single list or multiple lists.
“Search” Tab
The ET user interface 200 includes a search feature tab 545 that provides a user with a rich searching experience. By clicking the search tab 545 , the user can interact with a powerful search feature displayed by the ET user interface 200 that gives the user the capability to search all linked lists and databases. The search feature allows searching based on a number of different criteria (such as first name, last name, nickname, phone number, alias, building, department, office number, etc.). The search feature can perform the search within any of the linked lists or databases, the computing device running ET user interface 200 (such as a client), or on a backend server (such as the telephony server 215 ).
FIG. 6 illustrates the search feature tab 535 contained in the My Contacts environment 500 shown in FIG. 5 . In particular, in FIG. 6 the user has clicked on the search feature tab 535 and entered a search query 600 into the search box 560 . Based on the query 600 , the search feature has returned several possible matches 610 , with the highest probable match being displayed first and the other displayed in descending order. These possible matches 610 were obtained by searching each all of the information 300 available to the ET user interface 200 . The search feature also includes visual cues that inform the user which databases are being searched. For example, icons representing the available databases can be used to inform the user which database results were found. These results then are displayed with accompanying icons representing the databases where the results were found.
“Outlook Contacts” Tab
The “Outlook Contacts” tab 550 is a feature of the ET user interface 200 that integrates all contacts contained in Microsoft® Outlook. The Outlook contacts feature is useful if the user interacts mainly with persons outside the company rather than inside the company. In this case, the user frequently accesses his Outlook databases (within the personal databases 310 ) rather than the enterprise databases 320 . Multiple telephone numbers from Outlook are shown in a pull-down menu within the ET user interface 200 .
“Dialpad” Tab
The “Dialpad” feature tab 555 of the ET user interface 200 allows explicit dialing of a telephone number. FIG. 7 illustrates the dialpad feature tab 555 contained in the My Contacts environment 500 shown in FIG. 5 . When the user clicks on the “Dialpad” tab 555 , a telephone dialpad 700 is displayed in the activity region 450 . The user can use an input device (such as a stylus or mouse) to enter a telephone number in a text box 710 and click a Dial button 720 to dial the number. If the user makes a mistake entering the telephone number, a Clear button 730 can be used to erase the last number entered. The dialpad feature is useful on a computing device (such as a personal digital assistant (PDA)) where the user may not have a keyboard and may want to enter a number by tapping on the dialpad 700 .
Placing an Outgoing Call
Placing an outgoing call in the ET user interface 200 will now be explained with reference to FIG. 8 . FIG. 8 illustrates the ET user interface 200 as an outgoing call is initiated by a user. To place a call, the user clicks on a desired number 800 (shown as the third contact 575 ). If the telephone 270 linked to the ET user interface 200 is a speakerphone, the speakerphone goes off hook and the user hears the familiar telephone ringing sound. In addition, if the linked telephone 270 has a display, the number dialed is displayed on the phone display along with the person being called. It should be noted that although the person being called was selected from the Favorites list (as shown in FIG. 5 ), the call could have been initiated by the user from any of the other tabs in the “My Contacts” environment 500 .
FIG. 9 illustrates the ET user interface 200 during after the call initiated in FIG. 8 has been established. A call window 900 appears in the activity region 450 with the callee information 575 being displayed at the top of the call window. A notes area 910 is contained in the remainder to of the call window 900 , which allows the user to use the notes feature discussed below. The call status region 430 indicates that the user is “On the Phone” 920 . In addition, included in the environment button area is a hang-up button 930 that allows the user to terminate the call. In addition, the call may be terminated using the Hang Up process in the Call Control process region 520 .
The call window 900 may also appear by the user picking up the telephone. When the ET user interface 200 receives input that the telephone is off the hook, the call window 900 appears asking the user what number he would like dialed. Moreover, if the user dials the call from the telephone, the ET user interface 200 displays an in-call window (described below) and automatically recognizes the number called (if the number is in the databases). Moreover, the ET user interface 200 can bring up an address book or the favorites list automatically whenever the user takes the telephone off hook.
The ET user interface 200 can be customized to implement a company's dialing plan and policy for outgoing calls. As a simple example, the company dialing plan may require a “9” to reach an outside line. As a more complex example, company policy may dictate that a long distance certain carrier be used at specific times of the day and another be used otherwise. The ET user interface 200 can be customized to implement a company's dialing policy automatically without continual user intervention. Thus, the user can enter (either by cutting and pasting or directly from an input device) a telephone number and the ET user interface 200 will take care of all dialing policies and procedures. For example, if the user does not know how to dial a foreign country he simply enters the number and as the ET user interface 200 to dial for him. As another example, when the user is in a hotel and needs to dial out, the ET user interface 200 takes care of all dialing protocols to place the call without the user intervention.
Another feature of the ET user interface 200 is advanced call “camp”. If the user is trying to call someone and the person is unavailable, the advanced call camp feature notifies the user when the person becomes available and offers to place the call. In addition, the ET user interface 200 can use the callee's calendar to provide the user with the best times to call such that the person will be available. For example, the ET use interface 200 can monitor the messenger status of the person or the person's keyboard to determine when the person becomes available.
Other features can be used in the ET user interface 200 because it runs on a powerful PC that is linked and has access to a variety of databases. One such feature is the voice command feature. For example, with speech-to-text software (voice recognition software), the ET user interface 200 can process voice commands from the user. Thus, the user can vocally ask the system to call a certain person. For contacts with the linked databases, there is no training required. This is because the ET user interface 200 is linked to certain databases (such as the enterprise databases 320 and the personal databases 310 ) and is already aware of the contact being requested.
Call Transfer and Conference Calling Processes
Many telephones have the capability to transfer and conference calls. However, many people simply do not know how to use them. That is why many times you hear someone at the other end of the line say “if I lose you during this transfer or while trying to set up this conference call, please call back.” The ET user interface 200 simplifies call transfer and conference calling for the user.
FIG. 10 illustrates the ET user interface 200 during an establishment of a conference call by a user. In particular, in order to establish the conference call the user clicks on a conference button 1000 , under the “Call Control” process 520 in the process region 440 . Note also that the user has made notes 1010 in the notes area 900 , in accordance with the notes features discussed below. FIG. 11 illustrates the ET user interface 200 providing the user with a choice of contacts to conference in after the user request shown in FIG. 10 . This gives the user all the features tabs of the “My Contacts” environment 500 . In other words, the user can select contact from the Favorites tab 535 , the Recently Called tab 540 , the Outlook Contacts tab 550 , or click the Search tab 545 to perform a search or the Dialpad tab 555 to use the dialpad to call. Using one of these methods, a person can be called and added to the conference call.
ET user interface 200 also provides visual and audio cues to the user regarding the status of the call. FIG. 12 illustrates the cues used by the ET user interface 200 to update the user on the status of the conference call shown in FIGS. 10 and 11 . Specifically, the user selects a contact to include in the conference call and clicks on his telephone number 1200 . As shown in FIG. 12 , the contact is an unknown contact 1210 having an entry. A status window 1220 appears notifying the user that the person selected (the unknown contact 1220 ) is being included in the conference call. In addition to these visual cues, the telephone itself also provides audio cues (such as hearing the telephone dial). These audio cues provide the user with the capability to recognize any errors that may arise during the calling process and intercede. For example, if a line is busy, then the user can recognize that fact by hearing the busy tone and can choose to dial another number where the contact may be reached. The status window 1220 then informs the user to click “OK” 1230 when the person answers. This conferences the person into the conference call. If the person does not answer, the user can click “Cancel” 1240 to cancel the conference call. FIG. 13 illustrates the ET user interface 200 during a conference call that includes two callers, namely, the known caller 575 and unknown caller 1210 .
There are a number of other ways that the ET user interface 200 allows a user to establish a conference call. One way is by allowing the user to drag and drop a contact from other user interfaces and applications (such as an Outlook contacts list) and conference in those persons. Another way is that the user can right click on a contact and select the line, “join conference call”. Still another way is that the user can select all people on a “To:” line from an e-mail and right click on “conference call”. All of the selected people then are joined into a conference call. Moreover, groups can be created so that the user need only click on the group to establish a conference call including everyone in the group. In some embodiments of the ET user interface 200 , a synthetic voice or a recorded user voice is used to inform each contact being called for the conference call to wait until the entire conference call is established.
Incoming Call Features
The ET user interface 200 notifies the user of incoming calls both visually and audibly. FIG. 14 illustrates the ET user interface 200 during an incoming call. Visually, the user is notified on his desktop 1400 of the incoming call by an incoming call notification window 1410 . If caller identification is available on the telephone network and the telephone number is in any of the linked databases, the window will include the entry of the caller 575 containing contact information discussed above. If the user decides to answer the call, he simply clicks the Answer button 1420 and is connected with the caller. The ET user interface 200 instructs the telephone to pick up (or go “off hook”). If the telephone is a speakerphone, the ET user interface 200 also instructs the telephone to go to speakerphone mode such that the user can either talk using the speakerphone or pick up the handset. The call notification window 1410 also includes a quick transfer button 1430 discussed below. With the quick transfer button 1430 , the user is able to quickly transfer the incoming call to an alternate telephone.
The user also has a variety of options for the incoming call. The user can send an incoming call directly to voice mail by clicking a “Send Directly to Voice Mail” button (not shown) on the incoming call notification window 1410 . Alternatively, this could be an option listed under the quick transfer button 1430 . Either way, when the user clicks this option the ringing immediately stops and the caller is sent directly to voice mail. In another alternate embodiment, the ringing is silenced but the caller does not go directly to voice mail. Instead, the caller is sent to voice mail after the set number rings, but the ringing is silenced.
In addition, the ET user interface 200 provides the user with options when the user receives an incoming call while in a call. The ET user interface 200 allows the user in the call to send an instant message or e-mail to the caller notifying the caller that the user is on the phone and send the caller to voice mail. The voice mail can be caller-specific, whereby different voice mail messages are used dependent on the identity of the caller. For example, the user's supervisor and co-workers may get a more personalized voice mail message while those less familiar to the user may get less personalized and generic message.
The ET user interface 200 also gives a user call blocking options. The user may specify call blocking by clicking on a “block number and send to voice mail”. Whenever the caller from the blocked number calls again, the call is sent directly to voice mail without ringing. Alternatively, the user may choose to block calls completely from that number, in which case the caller may hear a message stating that the user is no longer accepting calls from their number.
If the incoming caller is using the ET user interface 200 , the caller can also receive alternatives to a busy signal. For example, if the caller tries to call the user but the user is on the phone, a dialog box will appear in the caller's ET user interface 200 . The dialog box can give the caller a variety of options, such as leave a voice mail, send an e-mail, send an instant message, notify me when the user is off the phone, do nothing, just to name a few. If the “notify me when the user is available” option is selected, a dialog box pops up on the caller's screen when the user is available and asks the caller if he would like to place a call to the user.
The user is also notified audibly of the incoming call. This is accomplished using ring tones through speakers of the PC. The PC has much richer speakers than a cell phone or desk telephone and allow a greater variety of ring tones. In addition, any sound file can be used to indicate an incoming call. The ET user interface 200 permits a user to turn off the ringer on the telephone and have the ring of an incoming call broadcast through the PC speakers. The advantage to this is that you can have a unique ring from your neighbor because there is a wider variety of sound files to choose from for a PC than from a cell phone or telephone.
The ET user interface 200 also provides audio as well as visual caller identification through the use of caller-specific ring tones. This means that the user can hear not only that his phone is ringing, but hear who the call is from based on the ring tone. The user then can decide whether to answer the call. In another embodiment, the sound file identifying a caller can be in the caller's voice. By way of example, a caller may identify himself in his own voice as “this is James calling”. Other embodiments of the ET user interface include text-to-speech conversion such that the textual caller identification is read and converted into speech. In this manner, a synthesized voice can announce that the user has an “incoming call from James.”
The incoming call notification window 1410 can also include the calendar of the person calling (not shown). Based on the caller's calendar, the user may make different decisions about answering the incoming call. For example, if the user sees from the caller's calendar that the caller has free time now but is in meetings for the rest of the day, the user may choose to answer the call. Similarly, if the user sees from the calendar that the caller is out of the office today, the user can decide to answer the call because the caller may need help with a matter. This additional information provided by the user's calendar aids the user in deciding whether to answer the call.
Quick Transfer Feature
Once a user is notified of an incoming call, the ET user interface 200 provides the user the option of performing a quick transfer. FIG. 15 illustrates the ET user interface 200 during a quick transfer of the incoming call shown in FIG. 14 . Referring to FIGS. 14 and 15 , the incoming call notification window 1410 includes the quick transfer button 1430 labeled, “Transfer to:”. As shown in FIG. 15 , the drop down vertical list 1500 includes the choices, “cell phone”, “home” and “Monica”. As noted above, the list 1500 may also include the option to send the caller directly to voice mail or to silence the ringing. This quick transfer feature can be used to transfer an incoming call to a telephone near the user when the user is away from the telephone being called. By way of example, suppose that the user is on the road and has his wireless notebook computer (running the ET user interface 200 ) and his cellular telephone. Back at his office is the user's work computer is running ET user interface 200 and his desk phone. Assume that an incoming call is received from someone calling the user's office telephone. As long as the user is connected to the network (such as via the wireless notebook computer), the user can use the quick transfer feature to immediately transfer the incoming call to the user's cell phone.
The user pre-configures the ET user interface 200 with the telephone numbers of locations where the user may be located. In addition, the calendar feature may be used to automatically determine the location of the user (based on his calendar) and add telephone numbers to the quick transfer list based on the calendar. This automatic population of the quick transfer list 1500 using calendar information allows the user to transfer incoming calls to a telephone at his present location. For example, if the user's calendar says that he is in a meeting in a conference room from between 9 and 10 in the morning, the ET quick transfer list 1500 would include the telephone number of the conference room during that time period. As shown in FIG. 15 , the user has received notification of an incoming call at his work office and has activated the quick transfer button 1430 to ring the incoming call at his home telephone number. The quick transfer feature of the ET user interface provides flexibility and lessens the chance that the user will miss important calls.
Call Forwarding Feature
The ET user interface 200 provides a user access to a call forwarding feature that forward calls to other telephones under certain conditions. These conditions can be configured by the user. For example, the user may want all incoming calls forwarded to his cellular phone every time his computer is locked. Other call forwarding conditions include: (a) forward all calls when the screen saver comes on; (b) forward all calls when my presence status is set to away or busy; and (c) forward all calls at certain times. For example, on Tuesday and Thursday the user may telecommute, such that all calls on those days are forwarded to her home telephone. The call forwarding feature also can be integrated with the calendar feature such that the feature recognizes from the calendar the location of the user at a certain times of the day and forwards (or offers to forward) all calls to a telephone at that location or to the user's cellular phone.
The ET user interface 200 also includes a “call hunt” feature. If there is no answer at a first number, the call hunt feature keeps trying different numbers in a “hunt group” where the user may be found. The alternate numbers in the hunt group can be provided by the user or automatically configured based on information from the linked databases such as calendar information. For example, if a caller is trying to reach a user at the user's office but there is no answer, the ET user interface 200 can attempt to reach the user at alternate numbers, such as the user's cell phone.
Missed Call Feature
In the event that a user misses an incoming call, the ET user interface 200 provides a missed call feature. Typically, the missed call feature is activated when a call is missed and the caller does not leave a voice mail message. FIG. 16 illustrates an example of an e-mail notification 1600 sent by the ET user interface 200 notifying a user of a missed call. The e-mail notification 1600 can be sent to any device capable of receiving e-mail, such as a computer or a cellular phone. One aspect of the missed call feature is that the ET user interface sends the e-mail notification 1600 to the user setting forth the identity of the caller 1610 , the time and date of the missed call 1620 and contact information. For example, as shown in FIG. 16 , this contact information includes the caller's telephone number 1630 and the caller's e-mail address 1640 . In addition, the e-mail notification 1600 includes instructions 1650 on how to turn off the e-mail notification feature.
The missed call e-mail notification 1600 can also contain buttons providing contact functionality. These buttons include a “call the missed caller back” button, an “e-mail the missed caller” button, and “use instant messenger to contact the missed caller” button. The user need only click any of these buttons to perform the desired action. The missed call notification e-mail 1600 also can use the caller's calendar information and present the caller's calendar. For example, the e-mail can contain a notice that says “you missed the caller, and here is her schedule for the day”. Her calendar then is presented. The user then looks at the missed caller's schedule and decides the best time to return her call. The missed call notification e-mail also can contain even richer information, such as the caller's picture. In addition, the missed call notification e-mail 1600 can include the voice command feature such that a user can verbally command the ET user interface 200 to contact the caller by any available method.
In some situations the incoming caller may be unknown. This can occur when the incoming caller's telephone number or other contact information cannot be found in the linked databases. In this unknown caller situation, the ET user interface 200 includes an unknown caller feature that can take a variety of actions. First, the unknown caller feature can provide as much information as possible to the user about the unknown caller. This can be done, for example, by area code lookup or a search of public Internet sites. In other words, the unknown caller feature can display to the user the geographic region from where the call originated, based on the area code. In addition, the unknown caller feature can perform a search of public Internet sites to find a name for the telephone number. This can include searching public telephone books and other public records.
The e-mail notification is different in the situation where the caller is unknown. FIG. 17 illustrates an example of an e-mail notification for an unknown caller. The unknown caller e-mail notification 1700 can be sent to any device capable of receiving e-mail, such as a computer or a cellular phone. The ET user interface sends the unknown caller e-mail notification 1700 to the user setting forth the telephone number of the caller 1710 , the time and the time and date of the missed call 1720 . In addition, the unknown caller e-mail notification 1700 also includes geographic information based on the caller's area code and the ability to perform a search on public Internet sites 1740 . The search is performed on the public Internet sites 1740 to perform reverse look-ups of telephone numbers. Moreover, the unknown caller e-mail notification 1700 includes instructions 1750 on how to turn off the e-mail notification feature.
The unknown caller feature also can intelligently determine whether the unknown caller e-mail notification should be standard or customized. The standard notification is based on the caller's name or number. There may be cases, however, when the name or number is not important, but, for example, the position of the person calling is important. For example, if a caller dials a corporation's main number and talks with an operator who then transfers the call, the standard e-mail notification would identify the caller as the company operator. In this situation, the operator's position is more important that the operator's name or number, and a customized e-mail notification would be sent. The ET user interface 200 can use linked databases (such as the enterprise database) to decide whether to send standard or custom e-mail notification.
In-Call Features
The ET user interface 200 provides can display several features and processes to a user during the initial stages of a telephone call and during the call.
Screen Sharing Feature
The screen sharing feature allows a user's computer to send instructions to display visual data to the computer attached to the caller's telephone. In other words, screen sharing is enabled if the user and a caller are in a call and if both callers are on the corporate network. There are two implementations of the screen sharing feature. A first implementation involves sharing the contents of the user's screen one or more callers. As shown in FIG. 5 , if the user is talking to a caller and wants to share his screen, the user clicks the “share your screen” button under the Collaborate process 530 . The caller then receives a message confirming that this is approved by the caller. This establishes a screen-sharing session between the user and caller. The screen call feature can be configured to share only a part of the screen, all of the screen, or an application-specific part of the screen (for example, the word-processing document open in a window on the screen. When the call is terminated, the screen-sharing session is automatically discontinued and all windows associated with the call and session are automatically cleaned up.
A second implementation of the screen sharing feature is a screen call feature. The screen call feature allows a user to call a business and to receive from the business a web page or other visual data associated with the business. The business has previously programmed its computer to send all callers its web page or other visual data. The screen call feature merges audio features of the telephone and PC with the visual features of the PC to provide information in a business setting. For example, assume that the user calls his favorite restaurant. While the user is on hold, the screen call feature can bring up the restaurant's web page, menu or available reservations, so that the user can browse this information while on the phone. Moreover, depending on its product or services, a business could provide information to the user via screen sharing such as a list of frequently asked questions, a movie listing, and a pricing list, just to name a few. The screen call feature also may be used to ease the burden of phone menu trees that require a user to select an option numerous times to get to the desired option. Using the screen call feature, the business could share its phone menu tree, thereby allowing the user to click on the menu tree for the desired option and letting the ET user interface 200 handle the task of reaching that option.
In addition, the ET user interface 200 includes an easy transfer feature that sends a file while in the call. This easy transfer feature shares multiple copies of the file while in a call with whomever the user chooses. By way of example, if the user is in a conference call with three other callers and they are discussing a document that the other three do not have, the user can click the easy transfer button and a copies of the document appears on the desktop of each of the three callers.
PC Audio Feature
The ET user interface 200 can adjust parameters on the PC based on the user's telephone usage. This is made possible by the fact that the ET user interface 200 is aware of the telephone and can act intelligently accordingly. Thus, the moment the ET user interface 200 knows what the phone is doing the ET user interface 200 can adjust certain parameters on the PC. For example, when the user picks up the telephone the audio on the PC is affected. This means that the audio on the PC may be muted or lowered, as desired by the user. In addition, the PC shows a visual indication that the volume has been affected. For example, the volume icon displayed on the screen may shown that the audio has been muted. Alternatively, a message may be displayed that the audio has been muted or turned down.
If the user is listening to music when a call is received or placed, the audio can be muted upon initiation of the call. In addition, the PC can pause the music at that location instead of turning the music off and forcing the user to listen to the beginning of a song upon termination of the telephone call. If the telephone call is, for example, a voice over IP (VOIP) call, the PC will sense this and act accordingly by switching the speakers from the audio to the telephone call and activating the microphone.
An alternate embodiment includes automatically lower the audio instead of muting it. In other words, upon receipt of initiation of a call, the audio is slowly lowered and then muted, while the music is paused. Upon call termination, the music is unpaused and then the audio volume is raised from mute to the previous level before the telephone call. This embodiment avoids the situations where the user has his audio on at a high volume, takes a phone call, and then upon termination of the call the audio returns to its high volume, thereby startling the user.
Notes Feature
The notes features of the ET user interface 200 provides support the user while in a call, while making a call, and while receiving a call. Referring to FIGS. 9 and 10 , during the call, can take notes (such as action items) in the notes area 910 . The user can take notes during the call and the notes will become part of the call history. In this manner, any notes made during a call are associated with the call. The notes can be any type of notes, such as text notes or Tablet PC format. In addition, these notes can be stored and indexed. This allows the user to search the notes using the search feature described above.
The notes features also can intelligently create headers and associations for the notes made during the call. These headers and associations can be automatically generated from data available to the ET user interface 200 , such as Outlook calendar data. For example, if the user has a meeting request in her calendar during the period that a call is placed or received, the notes feature looks to the Outlook calendar data to see what is scheduled. If, for example, there is scheduled a meeting to discuss a sale of a product, this data can be used to create a header for any notes created during the call, where the header states that the notes related to the sale. The notes feature attempts to match the call with the calendar items using, for example, caller identification, a meeting identification, or attempts to match the information between the calendar and the call. If a match is detected, the notes feature associated the notes created during the call with the meeting. In addition, this calendar data can be used to create note headers and such.
Event History Feature
The ET user interface 200 also can display an event history associated with one or more callers. This event history can be displayed for both incoming and outgoing calls to a particular caller for whom the user has had prior contact. The event history contains events such as appointments, prior telephone conversations, e-mails, notes and documents associated with a caller. The events are associated with the caller at the time of a call, and when the caller calls again, links to the events are displayed in the ET user interface 200 . The event history can be displayed for a caller in the incoming call notification window and when the user is placing an outgoing call. Through the ET user interface 200 , the user also can manually edit the event history to make it more useful.
By way of example, assume that a user receives a call from a caller with whom the user has had previous conversions. Further assume that the user and caller have previously discussed a certain document, which the user has opened during the course previous telephone conversations. These document may be, for example, a word processing or a spreadsheet document. The event history feature has previously linked that document with the caller and his previous telephone calls to and from the user. When a call is received from the caller, the incoming call notification window includes a listing of the document associated with the caller, and includes a link to the documents to enable the user to quickly open the document while answering the call. In other words, when a call is placed or received from the same caller at a later time, the event history feature remembers the events associated with the caller and the ET user interface 200 provides a list of those events during incoming or outgoing calls to the caller.
Other Uses of the Telephone
The ET user interface 200 allows a telephone to be used in other less traditional ways. For example, the ET user interface 200 can be used to provide wake-up calls or meetings reminders for the user. The user would simply enter into the ET user interface the times she wanted her phone to ring to be reminded of something or awakened. At the prescribed time, the telephone is directed to ring and the a reminder or wake-up call is provided. Moreover, the telephone can be used as an intercom (such as between offices). A user requests to intercom another person and an intercom request is sent to the person. The person's ET user interface 200 receives the intercom request and instantly takes the person's telephone “off hook”. The user and the person then are connected in an intercom setting.
“My Call History” Environment
The My Call History environment 515 provides a user with access to a history of all call activity within a previous period of time. In its basic form, the call history feature tracks all incoming and outgoing calls, including the length of call, participants, when and where the call occurred. Richer versions of the call history feature also include notes associated with the calls. The call history also can include an event history for each call, containing events associated with a particular caller. Other versions of the call history feature include tracking of all transferred, forwarded and missed calls, including a message that an e-mail was sent notifying the user of any missed calls). The call history feature can be configured to display information for multiple phones, such as a work phone, home phone, and cell phone. Moreover, the call history feature contains the capability to dial directly. In other words, while viewing the call history in the ET user interface 200 , a user need only click on a telephone number to initiate a call to that person.
The call history feature can include a statistical summary of call usage. This statistical summary provides a succinct digest of a user's telephone behavior over a certain time period. For example, the statistical summary may inform the user of the number of calls he made today and the average number of minutes per call, and the average number of minutes spent on the telephone during the day or week. In addition, the statistical summary can provide reports chronicling a user's time spent on the phone for each day, each month, or some other time period. The call history feature can be configured to automatically remove call history logs and information after a specified time period. The time period may be determined, for example, by a company's retention policy.
FIG. 18 illustrates an example of the Call History environment 515 . A call history log 1800 is displayed in the activity region 450 . This log 1800 contains a list of all incoming and outgoing calls as well as a preview of any notes that were taken during the call. If the user double clicks on an entry in the log 1800 , a window is opened detailing the basic information (such as data/time of the call, caller, telephone number) and all the notes. Processes 1810 for modifying the log 1800 are shown in the process region 440 . In particular, the processes 1810 include deleting individual log entries, delete all log entries, view selected log entries, and export the call history. Other processes may be added depending on the needs to the individual or enterprise.
My Telephones Environment
The My Telephones environment 510 allows a user to identify, configure and manage the telephones in communication with the ET user interface 200 . Identification and configuration such that the telephones will communicate with the ET user interface 200 can be performed manually or automatically. Automatic identification and configuration is performed based on the linked databases. The My Telephones environment 510 also provides status information regarding telephone and network connectivity.
Bestcom Environment
The Bestcom environment 505 is a communication preferences environment that provides a user with a means to configure and communicate to others the user's preferred modality of being contacted. In other words, the Bestcom (or communications preferences) environment 505 uses rules to route calls. These rules allow a call to be forwarded to a number based on a certain condition. For example, the user may state that his communications preferences are to have all calls forwarded to a certain number (such as his home phone) whenever his computer is locked. In addition, communication preferences of the use can be configured and communicated to others. For example, if a user prefers to be contacted by e-mail, this can be communicated to others through the ET user interface 200 (such as using an icon or text message). The communications preference environment 505 allows the user to notify potential callers of the way in which the user prefers to be contacted, thus improving the chances of contacting each other.
The ET user interface 200 serves as a means to collect and disseminate the user's communication preferences. The way these preferences are communicated include in the contact information, such as next to the person's telephone number and picture, and a communication preferences icon of some common states such as, for example, do not telephone, prefer e-mail, and please call. Because they are located in the contact information, these communication preferences would show up to a user searching for someone.
As an example, a user could set her communication preferences to certain settings such as: (a) please call any time; (b) prefer e-mail, but call if it is important; (c) please do not call; (d) send e-mail or stop by. These are merely examples of the multitude of settings that are available to convey the user's preferences. In addition, there could be other variations and dimensions to these communication preferences settings. For example, the settings may be based on the date, the time of day, the caller, and the user's presence status, to name a few.
FIG. 19 illustrates the settings process in the Bestcom or communication preferences environment 505 of the ET user interface 200 . The process region 440 includes the Bestcom Settings process 1900 , which allows the user to set communications and call forwarding preferences. As shown in FIG. 17 , the user interface options for the Bestcom Settings process 1900 are displayed in the activity region 450 .
In particular, the Bestcom Settings process 1900 allows the user to use the basic settings 1910 configured by the user. The user has the option of a Do Not Disturb status 1920 , which sends all incoming calls directly to voice mail. In this example, the user has configured the settings such that an incoming call is forwarded to her cell phone 1930 . This is performed only when the computer is locked 1940 . Other settings are possible, as shown in FIG. 19 . For example, the user can forward all calls to her cell phone. In addition, the PC can have a connected microphone that distinguishes between voices or a camera connected to the PC running face recognition software that detects other people in the room (other than the user). If the PC detects more than one person in the room or otherwise determines that there are persons other than the user in the room (either through audio or visual means), then the PC can automatically configure the settings to send all incoming calls to voice mail. Moreover, the settings can include a “breakthrough” list that allows call from certain people to get through. For example, a user may not want to be disturbed unless an incoming call is from a manager or a spouse.
The Bestcom environment 505 also allows remote notification and modification of settings. For example, the user can request by e-mail the current settings of the ET user interface. Once received, the user may decide to modify the settings. The modified settings can be e-mailed back to the ET user interface and applied.
The foregoing description of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description of the invention, but rather by the claims appended hereto.
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Enhanced telephony computer user interfaces seamlessly integrate and leverage the features of personal computers and telephones. The manner in which media is presented at a computing system can also be modified automatically in response to detected telephone operations. These modifications can include pausing media in response to a detected telephone call and/or adjusting a volume of the media presentation. The media presentation/volume can also be resumed/restored upon detecting that the telephone call has terminated.
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BACKGROUND
[0001] The present disclosure is directed to a device for controlling hydraulic pressure that has accumulated in a static hydraulic system. Specifically, the disclosure describes a system and device that prevents hydraulic fluid systems from over pressurizing and subsequently leaking hydraulic fluid to the environment.
[0002] The present invention generally relates to an apparatus for relieving hydraulic pressure in a hydraulic hose connected with hydraulically powered equipment in which the hose supplies hydraulic pressure to the equipment from a source of hydraulic pressure or returns hydraulic pressure from the equipment to a hydraulic fluid reservoir. The hydraulic hose is separable and connected to a hydraulic source by a quick coupler including a male and female component each of which includes a valve that is open as long as the quick coupler components are connected but will immediately close when the quick coupler components are disconnected thereby trapping hydraulic pressure in the hose. Any entrapped hydraulic pressure within the hose exerts pressure on the valve in the quick coupler component on the hose which makes it quite difficult to reconnect the male and female components of a quick coupler when reconnecting the hose to a hydraulic pressure source.
[0003] Referring to FIG. 1 , hydraulically powered equipment 10 is used for various purposes such as on tractor trailer trucks 12 (shown), various agricultural equipment, industrial equipment, fork lifts, and the like. The equipment usually includes a hydraulic ram in the form of a piston and cylinder assembly 14 , a hydraulic motor or the like connected to a source of hydraulic pressure 16 by flexible hoses 18 with control valves 20 being provided for controlling operation of the hydraulically powered equipment 10 . In many installations, such as a hydraulic trailer 22 , the hydraulic hoses 18 are connected to another hose or a tractor mounted hydraulic control valve by a quick coupler 24 which includes a male component and a female component which are quickly and easily connected by merely inserting the male component into the female component with interconnecting latching or detent structure securing the two components in connected, sealed relation.
[0004] Each of the two components in the quick coupler have a spring biased valve, usually a steel ball valve, engaged with a valve seat when the quick coupler components are disconnected. When the quick coupler 24 components are connected, the valves contact each other and move each other away from the valve seat thereby communicating the hose with another hose or a source of hydraulic pressure.
[0005] When the hydraulic trailer 22 is to be disconnected from the tractor 12 , the hydraulic control valve is closed and the quick coupler components disconnected by manually releasing the latch or detent structure with the valves closing when the quick coupler components are separated.
[0006] The steel ball in the quick coupler connected to the hose is pushed against its seat by the pressure within the hose which prevents hydraulic fluid or oil in the hose from draining onto the ground surface or the like.
[0007] Frequently, the hydraulic fluid on the trailer 22 will become heated and due to expansion of the hydraulic fluid in response to temperature changes will apply force to the hydraulic hose and maintain relatively high pressure in the hose. Then, when it is desired to recouple the quick coupler component on the hose to a quick coupler component connected to the tractor mounted hydraulic control valve, or to connect it to another hose, it is quite difficult to move the steel ball valve in the quick coupler component on the hose away from the valve seat.
[0008] The pressure in the hydraulics of the hydraulic trailer can reach as much as 600 psi. The high pressure has resulted in hydraulic fluid leaks to the environment.
[0009] What is needed is a hydraulic pressure reducer to prevent the hydraulic fluid from becoming pressurized when the trailer is disconnected.
SUMMARY
[0010] In accordance with the present disclosure, there is provided a hydraulic pressure reducer comprising a body having a first section and a second section coupled to the first section. A diaphragm is coupled between the first section and the second section. The first section and the second section define a fluid reservoir and an expansion region on opposite sides of the diaphragm. A biasing element is located in the expansion region, the biasing element is coupled to the diaphragm and is configured to bias the diaphragm responsive to a hydraulic fluid pressure acting on the diaphragm.
[0011] In an exemplary embodiment the fluid reservoir is configured to change volume responsive to a change of hydraulic fluid volume.
[0012] In an exemplary embodiment the diaphragm is configured to flex responsive to a change of hydraulic fluid volume, the hydraulic fluid volume comprising one of an expansion and a contraction.
[0013] In an exemplary embodiment the biasing element is configured to exert a force on the diaphragm and contract a volume of the fluid reservoir.
[0014] In an exemplary embodiment the biasing element is configured to change position responsive to a change of hydraulic fluid volume, the hydraulic fluid volume comprising one of an expansion and a contraction.
[0015] In an exemplary embodiment the biasing element comprises a disc coupled to a first end of a rod, the rod extends through the second section of the body.
[0016] In an exemplary embodiment the rod comprises a second end opposite the first end, the second end of the rod extends outside of the second section, an adjustable member coupled to the second end, the adjustable member is configured to change a length of travel of the rod relative to the second section of the body.
[0017] In an exemplary embodiment the hydraulic pressure reducer further comprises a spring coupled to the disc, the spring is configured to apply a force to the disc opposite the hydraulic fluid pressure.
[0018] In an exemplary embodiment the biasing element comprises a cushion of air in the expansion region.
[0019] In an exemplary embodiment the diaphragm comprises a piston disposed in a cylinder.
[0020] In an exemplary embodiment the piston disposed in the cylinder is coupled to the biasing element within the expansion region.
[0021] In an exemplary embodiment the piston disposed in the cylinder is coupled to the biasing element, the biasing element comprising a pair of springs coupled to an exterior of the body.
[0022] In another exemplary embodiment a hydraulic system comprises a hydraulic fluid circuit including a hydraulic pressure reducer. The hydraulic fluid circuit comprises a supply line and a return line. A quick connect coupler is fluidly coupled to each of the supply line and the return line. A hydraulic control valve set is coupled to the supply line and the return line downstream of the quick connect couplers. A hydraulic piston cylinder assembly is coupled to the supply line and the return line downstream of said hydraulic control valve set. The hydraulic pressure reducer is fluidly coupled to at least one of the supply line and the return line between the quick connect coupler and the hydraulic control valve set.
[0023] In an exemplary embodiment the hydraulic system further comprises a hydraulic trailer supporting the hydraulic fluid circuit.
[0024] In an exemplary embodiment the hydraulic system is detachably coupled to a hydraulic power source, the hydraulic power source coupled to at least one of a tractor trailer truck, an agricultural equipment device, a fork lift, an industrial equipment device.
[0025] In an exemplary embodiment the hydraulic pressure reducer comprises a body having a first section and a second section coupled to the first section; a diaphragm is coupled between the first section and the second section; the first section and the second section defining a fluid reservoir and an expansion region on opposite sides of the diaphragm; and a biasing element located in the expansion region, the biasing element coupled to the diaphragm and is configured to bias the diaphragm responsive to a hydraulic fluid pressure acting on the diaphragm.
[0026] In accordance with the present disclosure, there is provided a method of reducing excessive pressure in static hydraulic systems comprises coupling a hydraulic pressure reducer to the hydraulic system, wherein the hydraulic system comprises a hydraulic fluid circuit, the hydraulic fluid circuit comprises a supply line and a return line; a quick connect coupler is fluidly coupled to each of the supply line and the return line; a hydraulic control valve set is coupled to the supply line and the return line downstream of the quick connect couplers, a hydraulic piston cylinder assembly is coupled to the supply line and the return line downstream of the hydraulic control valve set; and the hydraulic pressure reducer is fluidly coupled to at least one of the supply line and the return line between the quick connect coupler and the hydraulic control valve set; wherein the hydraulic pressure reducer comprises a body having a first section and a second section coupled to the first section; a diaphragm is coupled between the first section and the second section; the first section and the second section defining a fluid reservoir and an expansion region on opposite sides of the diaphragm; and a biasing element is located in the expansion region, the biasing element is coupled to the diaphragm and configured to bias the diaphragm responsive to a hydraulic fluid pressure acting on the diaphragm; and changing a volume of the fluid reservoir and the expansion region of the hydraulic pressure reducer responsive to a change in a hydraulic fluid volume in the hydraulic system.
[0027] In an exemplary embodiment the method further comprises reconnecting a hydraulic power source to the hydraulic system quick connect coupler in the absence of hydraulic fluid pressure.
[0028] In an exemplary embodiment the method further comprises reducing hydraulic fluid leakage from the quick connect coupler by reducing hydraulic fluid pressure acting on the quick connect coupler.
[0029] In an exemplary embodiment the method further comprises replacing hydraulic fluid into the hydraulic system responsive to reconnection of the hydraulic power source to the quick connect coupler.
[0030] In an exemplary embodiment the method further comprises resetting the pressure reducer biasing element responsive to hydraulic fluid pressure changes.
[0031] Other details of the hydraulic pressure reducer are set forth in the following detailed description and the accompanying drawings wherein like reference numerals depict like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is an illustration of a tractor trailer with hydraulic trailer;
[0033] FIG. 2 is an illustration of an exemplary hydraulic system with hydraulic pressure reducer;
[0034] FIG. 3 is an illustration of the exemplary hydraulic pressure reducer;
[0035] FIG. 4 is an illustration of the exemplary alternative embodiment of a hydraulic pressure reducer;
[0036] FIG. 5 is an illustration of an exemplary alternative embodiment of a hydraulic pressure reducer;
[0037] FIG. 6 is an illustration of an exemplary alternative embodiment of a hydraulic pressure reducer.
DETAILED DESCRIPTION
[0038] Referring now to FIG. 2 , an exemplary hydraulic trailer 22 is shown equipped with a hydraulic pressure reducer, or simply reducer 26 . The hydraulic pressure reducer 26 is coupled to a hydraulic system 28 . The hydraulic system 28 includes, the hydraulic piston cylinder assembly 14 , control valves 20 and quick coupler 24 as described above configured to couple the hydraulic system 28 of the hydraulic trailer 22 to the source of hydraulic pressure 16 on the tractor truck 12 . The hydraulic system 28 includes the control valves 20 one for each of the return line 30 and supply line 32 of the hydraulic system 28 The reducer 26 can be installed between the quick coupler 24 and the control valves 20 on either one of the hydraulic lines, 30 , 32 . In a preferred embodiment, the reducer 26 is fluidly coupled to the return hydraulic line 30 , such that the hydraulic fluid can circulate normally in the hydraulic system 28 .
[0039] Referring to FIG. 3 , an exemplary hydraulic pressure reducer 26 is shown. The reducer 26 includes a body 34 including a first section 36 and second section 38 coupled to the first section 36 . The first section 36 and second section 38 can be bolted together in an exemplary embodiment. The first section 36 and second section 38 when coupled form a fluid reservoir 40 . The fluid reservoir 40 includes a diaphragm 42 that separates the reservoir 40 from an expansion region 44 . The expansion region 44 is shown proximate the second section 38 . The fluid reservoir 40 is configured to receive hydraulic fluid 46 from in the hydraulic line 30 . As the hydraulic fluid 46 expands in the hydraulic system 28 , the fluid reservoir 40 volume changes to accommodate the expansion. In the embodiment shown at FIG. 3 , the diaphragm 42 flexes to change the fluid reservoir 40 volume. The reducer 26 includes a biasing element 48 . The biasing element 48 is configured to bias the diaphragm 42 allowing the diaphragm 42 to flex responsive to the pressure of the hydraulic fluid 46 . As the hydraulic fluid 46 increases pressure, the diaphragm 42 flexes and expands the volume of the fluid reservoir 40 . As the hydraulic fluid 46 decreases in pressure, the diaphragm 42 flexes and contracts the volume of the fluid reservoir 40 . The biasing element 48 exerts a force on the diaphragm 42 to contract the volume of the fluid reservoir 40 . As the fluid reservoir 40 expands with the diaphragm 42 in response to the increased hydraulic pressure, the biasing element 48 yields and changes position.
[0040] In the embodiment shown in FIG. 3 , the biasing element 48 includes a disc 50 coupled to a first end 52 of a rod 54 that extends through the second section 38 of the body 34 . A second end 56 of the rod 54 extends outside of the second section 38 and includes an adjustable member 58 configured to translate along the rod 54 to change the length of travel the rod 54 translates relative to the second section 38 . A spring 60 is coupled to the disc 50 and is configured to apply the force on the disc 50 . The disc 50 applies force on the diaphragm 42 opposite the hydraulic fluid pressure forces, shown as arrows 62 applied on the diaphragm in the opposite direction of the spring force.
[0041] In operation the reducer 26 receives the hydraulic fluid 46 at a fluid coupling 64 , coupled to hydraulic line or simply, hose 30 of the hydraulic system 28 and fills the fluid reservoir 40 , expanding the volume. The fluid pressure 62 expands the diaphragm 42 . The biasing element 48 translates and retracts in response to the hydraulic fluid pressure 62 . The spring 60 changes position and increases in potential energy responsive to an increase in hydraulic fluid pressure. As the hydraulic fluid 46 pressure reduces the biasing element 48 presses the diaphragm 42 and contracts the reservoir 40 volume. The spring releases the potential energy and forces the diaphragm 42 against the decreasing hydraulic fluid pressure 62 . In practice, as the hydraulic fluid 46 increases pressure, for example due to thermal expansion, the reducer 26 expands hydraulic system volume to accommodate the increased pressure, thus minimizing the magnitude of the pressure in the hydraulic fluid 46 .
[0042] In exemplary embodiment, shown at FIG. 4 , the hydraulic pressure reducer 26 includes a body 34 with a coupling 64 coupled to a hydraulic line 30 . The biasing element 66 includes the flexible diaphragm 42 similar to the one shown at FIG. 3 , except there is no spring, rod and disc assembly included. The biasing element 66 and a cushion of air at a given pressure along with the flexible diaphragm 42 and the material properties of the diaphragm 42 are relied on to apply resistive pressure to the hydraulic fluid 46 . The diaphragm 42 reacts to the change in hydraulic fluid pressure similarly to the reducer configuration described above.
[0043] In exemplary embodiment, shown at FIG. 5 , the hydraulic pressure reducer 26 includes a body 34 with a coupling 64 coupled to a hydraulic line 30 . The diaphragm is configured as a piston 70 in cylinder 72 configuration that is coupled to a spring 74 and is relied on to apply resistive pressure to the hydraulic fluid 46 . A set of seals 76 , typically an O-ring, is utilized to seal the piston and cylinder interface, preventing the hydraulic fluid 46 from leaking past the piston 70 along the cylinder 72 and piston 70 interface. The spring 74 provides the force that acts on the piston 70 and responds to the changes in hydraulic pressure 62 .
[0044] In another exemplary embodiment, shown at FIG. 6 , the hydraulic pressure reducer 26 includes a body 34 with a coupling 64 coupled to a hydraulic line 30 . The biasing element 78 includes a piston 80 in cylinder 82 configuration that is coupled to a spring 84 and is relied on to apply resistive pressure to the hydraulic fluid 46 . In this embodiment, the spring 84 includes two springs coupled to an exterior 86 of the body 34 . The springs 84 bias the piston 80 against the hydraulic forces 62 . A similar seal can be employed in this embodiment between the piston 80 and cylinder 82 .
[0045] The hydraulic pressure reducer solves a longstanding problem of excessive hydraulic pressure in static hydraulic systems that have no hydraulic fluid reservoirs associated with the trailer or attachment. Every drop of hydraulic fluid that enters the hydraulic fluid system equals a drop of hydraulic fluid that exits the hydraulic system of the trailers or attachments. The reducer reduces pressure in static hydraulic system circuits, typically caused by thermal expansion of the hydraulic fluid due to temperature increases in the hydraulic fluid. The reducer is ideal for use with hydraulic trailers and other hydraulic equipment that are detachable from the hydraulic power source of the hydraulic system. The reducer enables easy reconnection of the hydraulic system at the quick connection couplers. The reducer functions well at low hydraulic pressures. The reducer prevents unwanted environmental degradation as it reduces the hydraulic fluid leaks that are associated with the over pressurization of the hydraulic fluid systems. The reducer automatically replaces the hydraulic fluid into the hydraulic system when the hydraulic system is re-connected at the quick connectors. The reducer also automatically resets to accommodate subsequent hydraulic system pressure changes. The reducer is configured to be employed in the hydraulic system and operate under full hydraulic pressure loads. The biasing element can be configured as a spring or as air pressure.
[0046] There has been provided a hydraulic pressure reducer configured to prevent hydraulic over pressure in hydraulic trailers. While the reducer has been described in the context of specific embodiments thereof, other unforeseen alternatives, modifications, and variations may become apparent to those skilled in the art having read the foregoing description. Accordingly, it is intended to embrace those alternatives, modifications, and variations which fall within the broad scope of the appended claims.
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A hydraulic system comprises a hydraulic fluid circuit including a hydraulic pressure reducer. The hydraulic fluid circuit comprises a supply line and a return line. A quick connect coupler is fluidly coupled to each of the supply line and the return line. A hydraulic control valve set is coupled to the supply line and the return line downstream of the quick connect couplers. A hydraulic piston cylinder assembly is coupled to the supply line and the return line downstream of said hydraulic control valve set. The hydraulic pressure reducer is fluidly coupled to at least one of the supply line and the return line between the quick connect coupler and the hydraulic control valve set.
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BACKGROUND OF THE INVENTION
This invention relates to light bulb mounts for use with vehicles and, in particular, to vibration inhibiting light bulb mounts.
It is known that vibrations caused by the traversing of a vehicle over a roadway such as those produced by the vehicle tires and the engine are passed through the vehicle frame and the like to associated light bulbs. Filaments which are part of such light bulbs are very susceptible to fatigue failure when vibrated at frequencies which are at or near harmonic frequencies of the filaments. Reduction in failure of such filaments is particularly important in commercial vehicles which are preferably in constant use.
Therefore, attempts have been made to design a light bulb housing and mount which inhibits the transmittal of harmonic vibrations caused by road travel to the light bulb filament. There have been many such light bulb housings designed which attempt to reduce such transmitted vibrations. In generaly none of the prior art designs have been effectual in reducing the transmission of harmonic vibrations to an acceptable extent.
OBJECTS OF THE INVENTION
Therefore, it is the object of the present invention to provide a resilient suspension mount for suspending light bulbs in an associated housing and which inhibits the transmittal of road traveling induced harmonic vibrations to the light bulb filaments; to provide such a mount which is made of a resilient material and comprises a light bulb receiving cup suspended between opposing, triangular or trapezoidal shaped arms, which arms support the light bulb mount on an associated housing; to further provide such a mount which when used with an associated housing allows a light bulb to be placed therein in only a predetermined orientation; to further provide such a mount where the light bulb is snugly retained therein without the use of a metallic socket; and to provide such a mount which is simple in design, easy to manufacture, capable of an extended life, and particularly useful for the intended use thereof.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.
The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a lamp housing which includes therein a lamp and a resilient suspension mount embodying the present invention.
FIG. 2 is a fragmentary and enlarged cross-sectional view of the lamp housing taken along line 2--2 of FIG. 1 showing the resilient suspension mount as it is supported in the lamp housing.
FIG. 3 is an enlarged and partial front elevational view of the lamp housing with portions of a housing lens broken away to show the suspension mount.
FIG. 4 is an enlarged and partial cross-sectional view of the lamp housing and suspension mount taken along lines 4--4 of FIG. 2.
FIG. 5 is an enlarged and partial cross-sectional view of the lamp housing and suspension mount taken along line 5--5 of FIG. 2.
FIG. 6 is an enlarged and partial cross-sectional view of the lamp housing and suspension mount taken along line 6--6 of FIG. 3.
FIG. 7 is an enlarged perspective view of the resilient support mount.
FIG. 8 is a front elevational view of the suspension mount shown in FIGS. 2-7, mounted in a modified lamp housing with portions of a lens of the modified housing broken away to show details thereof.
FIG. 9 is side elevational view of the modified lamp housing and suspension mount as shown in FIG. 8 with portions broken away to show details thereof.
FIG. 10 is a graph showing the results of vibrational tests made on the suspension mount.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
The reference numeral 1 generally designates a resilient suspension mount comprising this invention. As shown in FIG. 2, the suspension mount is supported within a lamp assembly structure such as a conventional vehicle lamp housing 2, which housing has defined therein a cavity 3 and which is operably covered by a lens 4.
The housing 2 further has a lip 5 which includes apertures 6 therein to allow the housing 2 to be secured to an associated vehicle frame or structure 7. The lens 4 is retained in covering relation to the housing cavity 3 by means such as an adhesive agent or the like (not shown). The lens 4 may be colored so as to conform with any desired function. For example, the lens could be red to function as a stop light and turn indicator light or the lens could be white to function as a backing indicator light. As shown in FIG. 1, multiple combinations of the housings 2 may be utilized in adjacent grouping for multiple purpose requirements, such as using a stop-turn indicator light housing with a backing indicator light housing.
The mount 1 is of preferably unitary molded construction of a resilient, rubber or plastic-like material, although it is foreseen that numerous materials of construction will perform satisfactorily under conditions in which the invention will be utilized. As best shown in FIG. 7, the mount 1 comprises a tubular bulb receiving cup portion 10, and opposed trapezoidally shaped arms 12 and 14 which extend outwardly from the cup 10 near a first end portion 15 thereof and are integral therewith. Preferably, the arms 12 and 14 are in a plane which bisects the cup 10 generally perpendicularly to the axis of the cup 10. Also preferably, the arms 12 and 14 are located at or near a first end portion of the cup 10. At free ends of arms 12 and 14 are tubular members 16 and 17 which contain therein passages 19 and 20 respectively. The tubular members 16 and 17 fit over and are snugly received and interferingly retained on attachment members such as elongate posts or the illustrated pegs 24 and 25 respectively, which pegs extend outwardly from a rear wall surface 26 of the lamp housing 2. Extending from the tubular member 16 in a direction parallel with a longitudinal axis of the cup 10 is a tab 30, the function of which will be explained later.
The arms 12 and 14 each have a pair of converging flanges 32 and 34 respectively, having a web 36 extending therebetween from opposed edges of the flanges 32 and 34. The web 36 is shown positioned on the side of the flanges 32 and 34 closest to the main body of the cup 10. A generally triangular recess 38 is thereby formed between the web 36 and the associated flanges 32 and 34.
An incandescent, filament-type light bulb 40 is operably received within the cup 10 so as to protrude from the first end portion 15 of the cup 10. An aperture 42 is positioned in an opposing cup end portion 44 which allows passage therethrough of associated wiring 46 for light bulb 40.
As best shown in FIG. 4, the light bulb 40 is of typical design and comprises a cylindrical metallic base portion 50 having oriented metal pins 52 extending radially outwardly therefrom at opposing circumferential positions. Depending on the manufactures of the bulb 40 the pins 52 can be formed at the same longitudinal position as shown in FIG. 5 or at different longitudinal positions. The bulb 40 further comprises a glass globe portion 54 in which are housed two filaments, a major filament 56 and a minor filament 58. An axis is formed through the arms 12 and 14 and pegs 24 and 25 about which the bulb 40 will tend to rotate if torque is applied to one of the opposite ends of the bulb 40. It is noted that the weights of the portions of the cup 10 on opposite sides of the arms 12 and 14 are preferably about equal such that no torque is applied to the first described axis when the housing 2 is in a generally static condition.
The cup 10 is designed so as to snugly receive and interferingly retain therein the bulb base 50 without using a metallic or the like auxilliary socket. Therefore, the suspension mount 1 can be one-piece molded while incorporating a resilient nature and, without further additions to the mount 1, the light bulb 40 can be operably positioned therein without any other manufacturing steps being undertaken, thereby saving labor.
As shown, the housing assembly 2 is utilized as the rear light unit for a commercial vehicle such as an over-the-road truck. The major filament 56 provides the lighting for stop and turn indicators, while the minor filament 58 provides continuous rear lighting for night driving. As shown in FIG. 5, filaments 56 and 58 are mounted on support members 62 and 64 respectively which extend outwardly from a globe base portion 60. The minor filament support member 64 is positioned rearwardly of and extends outwardly from the base portion 60 relative to the major filament support member 62. This orientation is necessary to provide the correct intensity of light emissions.
As shown in FIG. 5, pins 52 are received within apertures 65 and 66 which are formed in the cup 10, which pins 52 generally extend from the bulb base portion 50 at diametrically opposed positions, although some bulbs used with the present invention may not be so orientated and thus, the apertures corresponding to pins on the bulb would not be diametrically opposed. When the pins 52 are being positioned in the apertures 65 and 66 therefore, it is necessary for the person installing the bulb 40 to assure the proper filament orientation relative to the mount 1, that is the filaments 56 and 58 should be generally parallel to the arms 12 and 14 and the axis associated therewith. As stated before, some bulbs have pins 52 which are not diametrically opposed and in particular, are longitudinally spaced along the shaft of the bulb. When using such a bulb, the bulb may be positioned in the illustrated cup 10 such that only a single pin associated with the bulb is received in an aperture such as 68 in cup 10 or a specialized cup may be made having apertures to align with a particular bulb, thereby assuring that the proper orientation of the major and minor filaments 56 and 58 respectively is achieved.
The light bulb wiring 46 comprises a ground wire 71 which is connected to the metallic base 50 of the bulb and two lead wires 73 and 74 which run to major filament 56 and minor filament 58 respectively.
It is noted that the suspension mount 1 is generally symmetrical between the pegs 24 and 25, as shown in FIG. 7. As shown in FIGS. 3 and 4, the tab 30 which extends outwardly from arm 12 prohibits the placement of tubular member 16 over peg 25 since tab 30 would interferingly engage an auxilliary orientation peg 80 which extends outwardly from housing rear wall 26 adjacent peg 25, so that the mount 1 is urged into only one orientation on the housing 2. This further tends to assure that the proper orientations for the major filament 56 and the minor filament 58 are always attained.
Preferably, the suspension mount 1 is designed such that when a bulb 40 is placed therein, the assembled suspension mount 1 and bulb 40 are substantially supported about a common center of gravity. A plane passing through tubular members 16 and 17 including the axis thereof would generally pass through the center of gravity of the assembled suspension mount 1 and bulb 40. Further, a plane passing through tubular members 16 and 17 at a mid-point thereof and normal to an axis therethrough would also generally pass through the center of gravity of the assembled mount 1 and bulb 40. Also, the arms 12 and 14 are of equal length, such that the center of gravity of the assembled mount 1 and bulb 40 is generally equidistant between pegs 24 and 25. It is noted that the distance between pegs 24 and 25 is such that when the suspension mount is placed thereon, the suspension mount is tautly held between the two posts. Further, the wiring 46 is loosely received in the lamp housing 2 so as not to apply any stress to the suspension mount 1.
The suspension mount 1 is made of a suitable material that is resilient and pliable and which is also resistant to high temperatures since the temperature within the housing 2 can approach 300° Fahrenheit. The durometer of the material is preferably within a range of 40 to 75 and in particular, within the range of 55 to 60. It has been found that a material such as ethylene propylene, better known as EPDM, is a suitable material for the mount 1. The light bulb 40 may be a conventional light bulb commonly used in tail light assemblies which is commercially available and, which has major and minor filaments 56 and 58 respectively that are preferably fabricated of tungsten.
It is noted that conventional bulb filaments are susceptible to fatigue failure induced by vibration of the filaments due to vehicle vibration, such as engine imbalance and roadway irregularities encountered when an associated vehicle (not shown) travels over a roadway. When the frequency of the vibrations approaches the harmonic frequencies of the filaments fatigue failure is greatly enhanced. Therefore, it is very desirable to inhibit or dampen vibrations to the filaments particularly those that are at or near the harmonic frequencies of the filament.
Although the applicant does not want to be limited, the following is given as an explanation as to why the suspension mount effectively dampens the transmittal of roadway induced vibrations to the light bulb filaments 56 and 58. The arms 12 and 14, since they are made of a resilient material, tend to dampen vibrations to the light bulb 40 that would otherwise be transmitted thereto if the light bulb were rigidly mounted to the housing 3. Further, since the arms 12 and 14 are pliable the jolt of any violent movement such as caused by the traversing of bumps or railroad tracks is dampened thereby. Also, because of the design of the arms 12 and 14, notably the recess 38, the cup 10 is capable of flexure during violent movements while still retaining adequate strength to support the bulb 40 yet, because the arms 12 and 14 are trapezoidal, they tend to resist any rotation of the suspension mount about an axis through the arms 12 and 14.
It has been found that, if the thickness of the web 36, as shown in FIG. 4, is of the nature of 0.032 inches, the thickness of the arms 12 and 14 as viewed in FIG. 3 is approximately 0.140 inches and the width of flanges 32 and 34 as viewed from the left in FIG. 3, is approximately 0.100 inches that the suspension mount 1 will effectively dampen resonance in the filaments 56 and 54 when the frequency input to the suspension mount from an outside sources approaches the harmonic frequencies of the filaments, which for tungsten filaments, have been found to be between 300 and 450 hertz (Hz), and between 700 and 750 Hz.
Tests have been run on different configurations of the suspension mounts 1 to measure the ability of the mounts to inhibit or dampen vibrations of associated bulb filaments, particularly in the frequencies which are the harmonic frequencies of the filaments. Each test was conducted by placing a suspension mount on a stand which could be vibrated through a continuous range of frequencies.
FIG. 10 is a graph having a logarithmic scale which shows the results of tests made on two suspension mounts according to the present invention. On the horizontal axis the oscillation frequency in Hz input into the suspension mount is shown to simulate the oscillation frequency that is a result of traveling over a roadway. The vertical axis is a ratio of the oscillation frequency of the light bulb, as measured as close to the position of the filaments as possible, in relation to the input oscillation frequency. It is noted that the ratio of output to input approaches zero as the input frequency approaches the resonant frequency of the filaments. Curve A is the result of a test done with a suspension mount wherein the distance between a centerline axis of each passage, such as passages 19 and 20 as shown in FIG. 1, is 2.350 inches. Curve B is a result of tests made on a suspension mount having 2.000 inches between the centerlines of the passages.
In FIGS. 8 and 9 a resilient suspension mount 1a is shown which is essentially equivalent to mount 1 and has the same reference numerals followed by the suffix "a", being utilized with a different lamp assembly 100. The assembly 100 comprises a housing 102 and lens 104. As shown the suspension mount 1a is positioned on support pegs 106 such that the mount arms 12a and 14a are generally horizontal instead of vertical as shown in FIGS. 1 through 6.
It is foreseen that the suspension mount 1 is capable of being suspended in varying orientations. To do so, the strength of the arms 12 and 14 must be great enough to support the weight of the bulb 40 with only slight deformation of the arms 12 and 14 while still retaining enough resiliency and elasticity to dampen vibrations applied thereto.
It is to be understood that while certain embodiments of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown.
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A suspension mount is provided for suspending a light bulb in a lamp housing for use on vehicles, which mount inhibits the transmission of vibrations to the filaments in the light bulb. The mount is molded of a resilient material and comprises a light bulb receiving cup integrally formed with and suspended between two arms which support the mount on an associated housing. The arms are generally trapezoidal in plan view and have triangular recesses formed therein. Tubular members, having apertures therein, are formed in free ends of each arm. The tubular members fit over pegs extending outwardly from a surface of the lamp housing such that the mount is retained spaced apart from the housing surface.
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RELATED APPLICATIONS
This is a regularly filed application, based on provisional application Serial No. 60/198,424, filed Apr. 19, 2000.
TECHNICAL FIELD
The present invention relates to cooling of electrical and electronic components, and more particularly, to a cold plate utilizing fin configurations with an evaporating refrigerant to cool electrical and electronic components.
BACKGROUND OF THE INVENTION
Electrical and electronic components (e.g. microprocessors, IGBT's, power semiconductors etc.) generate heat which must be removed for reliable operation and long life of the components. One method of removing this heat is to mount the component on a cold plate, which is in turn cooled by a fluid flowing through it. Cold plates use a liquid flowing through tubes or offset strip fins or convoluted fins to remove heat from a surface where electrical or electronic components are mounted. The liquid flowing through the cold plate removes heat by an increase in its sensible temperature, with no phase change being involved. The tube or fins are in thermal contact with a flat surface where the components are mounted by means of screws, bolts or clips. A thermal interface material is usually employed to reduce the contact resistance between the component and the cold plate surface. There are many types of cold plate designs, some of which involve machined grooves instead of tubing to carry the fluid. However, all cold plate designs operate similarly by using the sensible heating of the fluid to remove heat. The heated fluid then flows to a remotely located air-cooled coil where ambient air cools the fluid before it returns to the pump and begins the cycle again.
Modern electrical and electronic components are required to dissipate larger quantities of heat at ever increasing heat flux densities. It is therefore very difficult to cool these components by sensible cooling only. For every watt of heat dissipated, the cooling fluid must increase in temperature; or if the temperature rise is fixed, the flow rate of fluid must increase. This causes either large fluid flow rates, or large temperature differences, or both. As fluid flow rate increases, pumping power goes up, as does this size of pumps required. This can cause unacceptable parasitic power consumption, equipment packaging difficulties, and even erosion of cold plate passages due to high fluid velocities. As the temperature rise of the cooling fluid increases, sometimes the allowable temperature of the device or component may be exceeded, causing premature failure.
It is seen then that there exists a continuing need for an improved method of removing heat from a surface where electrical or electronic components are mounted, particularly with the dissipation of larger quantities of heat at ever increasing heat flux densities being required.
SUMMARY OF THE INVENTION
This need is met by the present invention, which uses fin in multiple configurations, constructed as a part of a cold plate. The fin can be a high surface area offset strip fin, a plain convoluted fin, or other fin configurations. The cold plate of the present invention uses a vaporizable refrigerant as the fluid medium, passing through the fin configuration, to efficiently remove heat from components or devices mounted on the surface of the cold plate.
In accordance with one aspect of the present invention, an improved cold plate cooling system provides cooling away from the surface of electrical and electronic components with very low parasitic power consumption and very high heat transfer rates. The component to be cooled is in thermal contact with a cold plate. A fin material is inserted in the cold plate and refrigerant is circulated through the fin, allowing the cold plate and fin to transfer heat from the electrical or electronic components, as the liquid refrigerant is at least partially evaporated by the heat generated by the components.
Accordingly, it is an object of the present invention to provide cooling to electrical and electronic components. It is a further object of the present invention to provide cooling across large surface areas. It is yet another object of the present invention to provide nearly isothermal cooling to electrical and electronic components.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-3 are illustrations of fin configurations, including lanced and offset, plain, and ruffled, respectively; and
FIGS. 4-8 illustrate a cold plate assembly constructed in accordance with the present invention, using fin configurations such as are illustrated in FIGS. 1 - 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention proposes using fin in a cold plate, and passing a vaporizable refrigerant through the fin to remove heat from electrical and electronic components mounted to the surface of the cold plate. The refrigerant may be any suitable vaporizable refrigerant, such as, for example, R-134a. A cooling system which circulates a refrigerant as the working fluid is described and claimed in commonly assigned, co-pending application Ser. No. 09/819,591 (Attorney Docket TFF001PA), totally incorporated herein by reference.
The present invention proposes inserting fin into a cold plate, such as by brazing or otherwise associating the fin with the cold plate. The cold plate/fin cooling system uses a vaporizable refrigerant as the fluid medium through the fin to remove heat from components or devices in thermal contact with the cold plate. The cold plate acts as an evaporator, causing the refrigerant to vaporize and remove heat from the surface where the components are mounted. The fin configuration mounted integral to the cold plate helps to more efficiently transfer the heat and move the heat to the evaporating refrigerant. The fin configuration may be any suitable fin configuration, such as, for example, fin 10 a of FIG. 1 which illustrates lanced and offset convoluted fin; fin 10 b of FIG. 2, which illustrates plain convoluted fin; fin 10 c of FIG. 3, which illustrates ruffled convoluted fin; or other suitable fin configurations such as are manufactured and sold by Robinson Fin Machines, Inc., of Kenton, Ohio. Fin manufactured by Robinson Fin Machines, and suitable for application in the cold plate design of the present invention, can include any plain, ruffled, or louvered fin, with any manufacturable offset or crest configuration. The fin is available in a variety of materials suitable for heat transfer applications such as copper and aluminum. The particular fin configuration for each application can be selected based on the allowable pressure drop and required two phase heat transfer coefficient of the particular cooling system.
In accordance with the present invention, a cooling system 12 , as illustrated in FIGS. 4-8, uses fin 10 , such as fin 10 a , 10 b , or 10 c , in any of a number of configurations to construct a cold plate 14 , for efficiently transferring heat. The cooling system 12 uses a vaporizable refrigerant directed through the system 12 in the direction of arrow 16 as the fluid medium to remove heat from components or devices 18 mounted on, or otherwise in thermal contact with, the surface 20 of cold plate 14 .
As illustrated in FIGS. 4 and 5, refrigerant enters the system 12 at a refrigerant inlet 22 , and exits the system 12 at a refrigerant outlet 24 . The refrigerant is evaporating as it flows through the cold plate. FIG. 4 illustrates the completed cold plate 14 assembly. For purposes of illustration only, and not to be considered as limiting the scope of the invention, a heat generating electrical or electronic component 18 is shown as being mounted to a flat area 26 on surface 20 of the cold plate 14 . However, it will be obvious to those skilled in the art that the actual means for mounting or attaching the components 18 to the cold plate 14 can be any suitable means which put the components 18 in thermal contact with the cold plate 14 , such as but not limited to thermally conductive adhesive, bolting, clips, clamping, or other mechanical means, and soldering.
Referring now to FIG. 5, there is illustrated a partially exploded view of the cold plate 14 assembly of FIG. 4 . In FIG. 5, the refrigerant inlet 22 and outlet 24 are shown, as well as a liquid refrigerant distribution means 28 . The liquid refrigerant distribution means 28 comprises a plurality of grooves or channels 30 , formed in member 32 of assembly 12 . The arrangement of the flow channels 30 are intended to enhance the introduction of the fluid medium to the fin configuration. Therefore, the arrangement can vary, depending on the size and type of fin used, and the heat transfer requirements of the particular system.
FIG. 6 illustrates an exploded view of the cold plate body 14 with the fin 10 visible. In a preferred embodiment of the present invention, the assembly 12 is designed to be brazed, so that the fin 10 becomes integral with and a part of the structural support of top and bottom plates 14 a and 14 b , respectively. The fin 10 is in intimate heat transfer contact with both plates 14 a and 14 b . Members 34 can be used to hold the plates 14 a and 14 b together, maintaining the fin 10 in heat transfer contact with the plates.
FIG. 7 is a cutaway view showing the liquid refrigerant distribution means 28 and the fin 10 sitting on bottom plate 14 b . Also shown is the transition from channels 30 to a tube type structure for allowing the refrigerant to exit the cold plate via outlet 24 of FIGS. 4 and 5. The cold plate with the fin, as best illustrated in FIGS. 6 and 7, allows distribution of liquid refrigerant into the flow channels 30 , to evenly distribute the liquid throughout the fin 10 configuration. This prevents the formation of hot spots and pressure spikes during the cooling process. Introducing the liquid refrigerant to the fin 10 via channels 30 allows for efficient distribution of the fluid medium through the fin, and allows the fin to be used to control the boiling separation that is occurring as the liquid refrigerant absorbs heat from component(s) 18 and turns to vapor (as it boils). Some liquid refrigerant is therefore continuously moving through the fin 10 . With the arrangement illustrated herein, the present invention does not need to increase the temperature of the cooling fluid to dissipate heat; rather, the heat generated by components 18 is absorbed, causing the refrigerant to boil, and turning the refrigerant from a liquid to a gas.
Referring now to FIG. 8, there is illustrated a view of one end of the cold plate assembly 12 . Fin 10 is inserted between the top and bottom plates 14 a and 14 b , respectively, and members 34 hold the plates 14 a and 14 b together. Members 32 introduce the flow channels 30 to the system 12 , to directionally affect the flow of refrigerant to the fin 10 . Finally, members 36 retain the inlet 22 and the outlet 24 , in fluid relationship with the flow channels 30 . In a preferred embodiment of the present invention, the sections or members 32 , 34 and 36 are sealed by O-rings 38 , and external connections are made.
In a preferred embodiment of the present invention, the cold plate assembly 12 has been designed to use a fluorocarbon refrigerant, R-134a, which is non-toxic and has thermo physical properties particularly suitable for cooling applications, such as latent heat of vaporization, vapor pressure and compatibility with common materials of construction. However, it will be obvious to those skilled in the art that many other refrigerants may be used, depending on the specific thermal requirements of the system. These may include, but are not limited to, R-12, R-22, R-401a, R-401c, R-410a, R-508a, HP-80 and MP-39. The present invention introduces a vaporizable refrigerant to fin integrally associated with a cold plate to achieve benefits not previously realized with existing systems. The refrigerant may either completely or only partially evaporate, depending on the system heat load generated, as it flows through the cold plate. The heat transport mechanism is the evaporation of refrigerant removing heat from a surface where the components or devices are mounted.
The improved cold plate cooling system of the present invention, therefore, comprises at least one component that is generating heat and is required to be cooled. The cold plate is in thermal contact with the component(s), which cold plate has a fin configuration integral thereto. The fin configuration provides cooling across an entire desired area. The vaporizable refrigerant is circulated to the cold plate through the fin configuration, whereby the cold plate operates as an evaporator causing the vaporizable refrigerant to at least partially vaporize and remove heat generated by the component(s) from a surface of the cold plate. In accordance with the present invention, the fin configuration is located to control liquid-gas two phase flow of the vaporizable refrigerant.
In a preferred embodiment of the invention, a refrigerant inlet and a refrigerant outlet are associated with the cold plate and the fin configuration. A liquid form of the vaporizable refrigerant enters the cooling system at the inlet and passes through the fin configuration, turning to vapor as heat is removed from the component and leaving as vapor or a mixture of liquid and vapor. By using a vaporizable refrigerant, in combination with the fin configuration, several major improvements over conventional cold plates are realized. First, since the latent heat of vaporization of refrigerants is much higher than the sensible heat capacity of ordinary fluids, the mass flow rate required for a given amount of cooling is much less than in a conventional cooling system. Pumping power is reduced and line sizes along with flow area are also reduced, resulting in more cost effective systems. As the refrigerant evaporates, the latent heat is added at a constant temperature as with any single-phase evaporation process. This allows the cold plate to remove heat nearly isothermally, keeping the components and devices cooler than is possible with prior art systems. Furthermore, evaporation of refrigerant in the cold plate allows for much higher heat flux densities than in conventional cold plates. This is due to the much higher boiling heat transfer coefficients, as compared to the single phase forced convection coefficients in the prior art. High performance microprocessors with small silicon die and high heat flux densities can be cooled effectively with the cooling system of the present invention.
With a cooling system constructed in accordance with the present invention, the use of offset strip fin or convoluted fin as the evaporating surface allows the cold plate to be cooled uniformly over the entire surface, unlike cold plates with tubes mounted to flat surfaces where thermal spreading is a consideration. The use of fin in a cold plate evaporator, as taught by the subject invention, allows for the mounting of components almost anywhere on the cold plate, since nearly the entire surface of the cold plate is uniformly cooled.
Having described the invention in detail and by reference to the preferred embodiment thereof, it will be apparent that other modifications and variations are possible without departing from the scope of the invention defined in the appended claims.
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An improved cold plate cooling system provides cooling away from the surface of electrical and electronic components with very low parasitic power consumption and very high heat transfer rates. The component to be cooled is in thermal contact with a cold plate. A fin material is inserted in the cold plate and refrigerant is circulated through the fin, allowing the cold plate and fin to transfer heat from the electrical or electronic components, as the liquid refrigerant is at least partially evaporated by the heat generated by the components.
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FIELD OF THE INVENTION
[0001] This invention relates in general to the treatment of wastewater and deals more particularly with a method and apparatus for use in a new lagoon or basin or for upgrading existing lagoon systems in a manner to enhance the wastewater treatment.
BACKGROUND OF THE INVENTION
[0002] Lagoon systems for treatment of wastewater have long been in use and have achieved considerable popularity, especially in areas where land is readily available. A lagoon system typically involves use of an earthen basin in which the wastewater is contained. The organic wastes are converted to biological solids, either by operating the system as a simple stabilization pond or by using low rate partial mix aeration. The biological solids eventually settle and are retained on the bottom of the lagoon.
[0003] Aerated lagoon systems are simple and economically advantageous because expensive equipment is not required and there is no need for highly trained personnel to operate the facility. However, substantial amounts of land are required because of the need to detain the wastewater in the lagoon for an extended period to achieve significant levels of treatment. Also, the overall capacity or treatment level is limited, as virtually no flexibility is available in the treatment process.
[0004] By way of example, a typical lagoon system may require 15 to 30 days detention time to remove most carbonaceous BOD and oxidize ammonia during warm weather. In the upper midwest and other relatively cold climates, the lagoon temperature in the winter is too cold for nitrification to be carried out. With the increased emphasis that is being placed on the nitrification of ammonia, and with regulatory requirements being gradually expanded to require nitrification for all systems, the basic lagoon technology is severely handicapped due to its inability to consistently nitrify ammonia, particularly in cold climates. Many small municipalities have significant investment in an existing lagoon system and lack the financial capability to construct more advanced treatment facilities such as an activated sludge plant that is capable of meeting the regulatory requirements for nitrification and/or denitrification. Further, the costs of training operating personnel and maintaining more sophisticated systems are often beyond the capability of rural water districts and small municipalities.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a method and apparatus for treating wastewater that makes use of a new or existing lagoon facility and involves operating the lagoon in a manner to treat wastewater using more advanced techniques that allow nitrification and/or denitrification.
[0006] In accordance with the invention, the performance of a new or existing lagoon system is enhanced by providing baffles or added earthen berms that create a complete mix bioreactor zone at the front end of the basin or lagoon, or elsewhere if desired. The complete mix zone is operated using a low rate activated sludge process that involves complete mixing of the wastewater using only a small portion of the existing lagoon with a much shorter detention time than the original lagoon, or a shorter detention time than typical lagoon practice in the case of a new lagoon application.
[0007] A suitable aeration system is installed in the complete mix zone and may include floating air supply laterals from which air diffusers are suspended near the bottom of the lagoon. This type of aeration system can be installed without requiring de-watering of the basin and can accommodate uneven basin floors. Also installed in the complete mix zone is one or more bioconcentration modules which are preferably suspended from the floating air laterals or from floats or in another fashion. The bioconcentration modules do not function as clarifiers but instead provide settling chambers that are open at the top and bottom. The bioconcentration modules are internal to the bioreactor zone where aeration and mixing occur. Solids are concentrated in the bioconcentration chambers and drop by gravity out through the bottom of the settling chamber, thus returning them into the active bioreactor zone. This automatic return of solids maintains sufficient bacteria in the complete mix bioreactor zone to sustain a relatively high rate of biological activity. The solids are returned and are remixed in the complete mix zone by the aeration system and are circulated throughout the zone to maintain the proper active biomass for a complete mix process in the bioreactor zone.
[0008] Biomass concentrations in the bioreactor zone increase after start up with a very large percentage of all solids returned by the bioconcentration module at first (i.e., only a small amount of solids initially escape over the weir or other device used to control the discharge from the module). Continued operation of the system results in an increased level of biomass in the bioreactor zone until an equilibrium state of solids growth and return is reached, at which time escape of solids over the weir or other control device is higher.
[0009] Biomass equilibrium is thus achieved in the complete mix zone, and excess solids then simply pass into the rest of the lagoon where they eventually settle and are subject to the normal lagoon treatment process. In most systems, the detention time in the complete mix zone is 1-2 days as compared to 15-30 days in the original lagoon operated conventionally. When biological equilibrium is reached, the MLSS level is typically 1000 mg/l to 5000 mg/l. in the bioreactor zone.
[0010] The complete mix zone is typically operated as a low rate activated sludge process with an F/M ratio between 0.05 and 0.30. The system normally operates with a sludge age between 40 and 50 days. Sufficient sludge age is provided to effect complete nitrification because heat is conserved and maintained even in cold weather conditions. The relatively short detention time of 1-2 days maintains the temperature in the complete mix bioreactor zone high enough to accommodate biological nitrification.
[0011] Rather than monitoring and managing the sludge concentrations with separate clarifiers and controlled sludge recirculation, as occurs in extended aeration, conventional, or high rate activated sludge processes, the complete mix zone is simply allowed to reach a natural biomass equilibrium condition. Biomass from the bioconcentration modules is retained in the complete mix bioreactor zone. Excess solids from the system are discharged into the second or polishing lagoon with the bioreactor effluent where they are subjected to stabilization pond treatment with or without aeration.
[0012] The benefits achieved by the present invention are significant both economically and because of the enhanced wastewater treatment. The cost of upgrading an existing lagoon or constructing a new lagoon with advanced treatment is modest because use can be made of the existing basins, existing pumping and hydraulics, existing sludge disposal, a baffle, an aeration system, and the necessary settling modules as the primary upgrade modules. The treatment flexibility and capability are improved markedly in the upgrade because there is a high degree of carbonaceous and BOD removal and nitrification can be effected as well as denitrification as an option. Because biomass equilibrium is reached naturally in the mixed bioreactor zone using the bioconcentration modules, a wide range of effluents and a wide range of design conditions can be accommodated. At the same time, the basic simplicity of the lagoon system is retained and there is no need for a major increase in the training level or technical abilities of operating personnel.
[0013] Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In the accompanying drawings which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:
[0015] [0015]FIG. 1 is a schematic diagram of a wastewater treatment process carried out in accordance with a preferred embodiment of the present invention;
[0016] [0016]FIG. 2 is a diagrammatic top plan view of a lagoon wastewater treatment system that is upgraded to carry out a treatment process in accordance with a preferred embodiment of the present invention; and
[0017] [0017]FIG. 3 is a fragmentary sectional view on an enlarged scale taken generally along line 3 - 3 of FIG. 2 in the direction of the arrows.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Referring now to the drawings in more detail, the present invention is directed to an enhancement to a conventional lagoon wastewater treatment system. Referring initially to FIG. 1, numeral 10 generally designates a basin or lagoon into which wastewater influent is directed, as indicated by the directional arrow 12 . Another earthen basin 14 is located adjacent to and downstream from basin 10 and may be separated from basin 10 by an earthen berm 16 or similar structure. The basin 14 may be partitioned by a baffle 18 into two separate zones 20 and 22 which may be subject to conventional lagoon treatment processes such as a stabilization pond operation or partial mix aeration. The effluent is discharged from zone 22 , as indicated by the directional arrow 24 .
[0019] In accordance with the present invention, the first basin 10 is partitioned by an earthen berm or baffle 26 into two different zones. The first zone 28 at the front end of the treatment system is a complete mix zone in which a low rate activated sludge process is carried out. The other zone 30 is located downstream from the complete mix zone 28 and may be operated as a stabilization pond or as an extended aeration or partial mix basin. The complete mix zone 28 is considerably smaller than the remaining zones 30 , 20 and 22 and is operated in a different fashion.
[0020] With additional reference to FIG. 2 in particular, the complete mix zone 28 is equipped with an aeration system that may include a conventional blower 32 supplying air to a header pipe 34 that extends along the front end of basin 10 . The header pipe 34 may connect with a plurality of floating air supply laterals 36 , preferably through suitable valves 38 . As shown in FIG. 3, each of the laterals 36 floats on the surface of the wastewater contained in the complete mix zone 28 . With continued reference to FIG. 3 in particular, a plurality of tubular air diffusers 40 are suspended from each of the floating laterals 36 . A flexible hose 42 extends downwardly from lateral 36 and connects at its lower end with the diffuser 40 in order to suspend the diffuser above the basin floor 44 and also to supply air to the diffuser from the lateral 36 . The diffusers 40 are located near but above the basin floor 44 .
[0021] While surface aeration, fixed grid aeration, submerged laterals, or other types of aeration systems can be used, an aeration system that makes use of floating air supply laterals and suspended fine bubble diffusers is preferred, especially with an existing lagoon or basin, as it can be installed without the need to de-water the basin 10 of the existing lagoon system. In addition, the fine bubble aerators 40 operate efficiently for mixing and transfer of air to the wastewater that is undergoing treatment. It should be understood that the air laterals 36 can be arranged to extend perpendicular to the direction of flow or in other patterns as alternatives to the arrangement shown in FIG. 2.
[0022] As shown in FIG. 2, there may be a number of laterals 36 extending to a location adjacent to the baffle 26 , and each lateral 36 is provided with a number of the diffusers 40 which are typically spaced apart uniformly throughout the complete mix zone 28 . However, virtually any number of supply laterals and any number and type of diffusers can be installed in the complete mix zone 28 . It is necessary for the aeration system to be capable of continuously or intermittently mixing the wastewater completely in the complete mix zone 28 along with the solids retained from the bioconcentration modules in order to achieve the benefits of the present invention.
[0023] Many or all of the floating air laterals 36 can be equipped with a bioconcentration module 46 which may be located near the baffle 26 or at other strategic locations to optimize the biological process. Each bioconcentration module 46 is preferably a rectangular structure that provides a stilling well effect and a bioconcentration chamber inside of it. As best shown in FIG. 3, each module 46 has an open top 48 and is supported by the floating laterals 36 or by an integral float structure as part of the module. Wastewater is admitted to the bioconcentration chamber from its open bottom 50 , as indicated by the directional arrow 52 . Solids drop out of the bioconcentration chamber through its bottom 50 after they have been concentrated within the bioconcentration chamber, as indicated by the directional arrows 54 . Each module 46 may be provided with a weir 56 or other discharge device from which effluent discharges from the settling chamber. Each module 46 is preferably spaced above the basin floor 44 and may be provided with a float structure in order to maintain its position. Preferably, each module 46 is suspended from a corresponding air lateral 36 , as by means of straps 58 or any other suitable tethering device.
[0024] Weirs, decanters or other collection devices may be provided at the tops of the bioconcentration modules 46 to remove effluent liquid and excess biosolids from the complete mix zone to the settling/stabilization zone. The top of the module 46 is preferable above the liquid level with the weir 56 or other discharge device extending downstream at a location near the liquid level to direct effluent and excess solids out of the bioconcentration chamber as indicated by the directional arrow 59 in FIG. 3.
[0025] As shown in FIG. 3, baffle 26 may have one or more passages 60 to accommodate the flow of material from the complete mix zone 28 into the succeeding zone 30 . An option is to install individual control values for each passage.
[0026] In accordance with the present invention, the complete mix zone 28 can be newly constructed or created in an existing lagoon system in order to upgrade the capabilities of the lagoon system for treating wastewater and particularly for effecting advanced treatment levels of biological nitrification of ammonia and/or biological denitrification. The baffle 26 is installed in basin 10 , and the aeration system and settling modules 46 are installed in the complete mix zone 28 .
[0027] In operation, influent wastewater is typically admitted to the complete mix zone 28 at the front end of the system (although the complete mix system can be located elsewhere in one of the basins if desired). In a typical application, the wastewater is detained in the complete mix zone for approximately 1-2 days (up to 5 days in some applications), and in the remainder of the lagoon treatment system for 2-30 days. The process that is used is based on a design that provides sufficient sludge age for full nitrification, typically 40 to 50 days. The strength of the waste can create major variations in the detention times, but the sludge age or f/m ratio will be similar in all cases for proper operation of the process.
[0028] The wastewater in the complete mix zone 28 enters the settling modules 46 in which the solids in the wastewater are concentrated and returned to the bioreactor. The solids drop through the bottom 52 of each module 46 back into the complete mix bioreactor zone 28 , and the action of the air diffusers 40 causes a complete mixing of the solids and recirculation throughout the volume of the complete mix zone 28 . The modules 46 do not serve as clarifiers but instead act as concentration devices that maintain adequate biomass in the complete mix zone to assure sufficient bacteria to sustain the biological process. The modules 46 are designed to allow routine loss of excess solids along with the effluent into the subsequent polishing lagoons. In most applications, the complete mix zone is operated as a low rate, complete mix, activated sludge process with sludge age of 40 to 50 days.
[0029] As the system operates, the complete mix zone 28 reaches a biomass equilibrium condition, with the solids concentration at the equilibrium condition depending upon a number of factors, including detention time, the design and operation of the bioconcentration modules, temperature and organic load of the system. Normally, the MLSS level at equilibrium is between 1000 mg/l and 5000 mg/l to maintain proper sludge age. However, it may be desirable to operate some systems at elevated levels as high as 10,000 mg/l to obtain proper sludge age. Once equilibrium conditions have been reached, any excess solids pass through the settling modules and are eventually directed into zone 30 and the remaining zones 20 and 22 along with the effluent passing over the weir 56 . In these zones, the wastewater is treated by a conventional lagoon process that may involve stabilization pond operation or partial mix lagoon aeration. In any event, the solids settle and are biologically stabilized in the lagoon and the treated effluent is eventually directed out of the treatment system as indicated by directional arrow 24 in FIG. 1. A principal advantage of upgrading the lagoon system in accordance with the present invention involves the ability to achieve advanced levels of treatment, i.e., nitrification and/or denitrification with minimum operator attention. The operation of the complete mix zone 28 as a low rate activated sludge process creates an f/m ratio that is typically in the range of about 0.05 to 0.30, which allows sufficient sludge age to accomplish full nitrification even in cold weather applications. This low rate nitrification typically has a sludge age of 40 to 50 days. The high biomass levels in the bioreactor zone combined with a relatively short detention time of 1-2 days in the complete mix zone 28 , permits the necessary heat to be retained in the process to allow biological nitrification to occur.
[0030] The excess solids that are suspended in the wastewater effluent from the complete mix zone 28 are not managed but are instead freely discharged into the remainder of the lagoon where stabilization occurs either by means of a partial mix aerated lagoon process or a non-aerated stabilization pond process. The effluent from such a system can be expected to have a BOD level less than 20 mg/l, suspended solid levels less than 20 mg/l and nitrification adequate to convert ammonia to nitrate with the effluent nitrogen ammonia content being less than 1 mg/l. Additionally, the process of the present invention can be modified to achieve higher levels of treatment, including denitrification by adding a selector zone at the front end of the complete mix zone and recirculating MLSS through the selector zone or by bio-augmentation through feed of micro-organism cultures to enhance or supplement specific types of bacteria or other desirable organisms such as nitrification organism cultures.
[0031] The benefits of the present invention include use of an existing lagoon system with only modest upgrading costs, the ability to accomplish full nitrification even in cold climates, enhanced process flexibility, the ability for expansion to carry out denitrification, minimization of sludge handling and simplicity without the need for significant added training for operating personnel.
[0032] From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure.
[0033] It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
[0034] Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.
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A method and apparatus for building a lagoon based advanced treatment system or upgrading an existing lagoon system for advanced treatment of wastewater. The lagoon is provided with a baffle to create a complete mix zone in which an aeration system and bioconcentration modules are installed. Biological solids are concentrated in the modules and drop through their open bottoms where the solids are recirculated and mixed by the aeration system. Once a biomass equilibrium is reached in the complete mix zone, excess solids are passed into the rest of the lagoon for standard treatment there. The complete mix zone is operated as a low rate activated sludge process with a detention time much less than for the rest of the lagoon, maintaining sufficient heat and sludge aging to effect complete biological nitrification and/or denitrification.
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BACKGROUND OF THE INVENTION
[0001] (1) Field of the Invention
[0002] The present invention pertains to a register assembly that can be used to cover duct openings that supply a flow of heated or cooled air to a room of a structure, and can also be used to cover duct openings that receive return air from the room. In particular, the register assembly is comprised of a framed faceplate, a plurality of damper assemblies of different sizes, and a plurality of connectors that are adjustably connected to the faceplate to adapt the faceplate to each different size of damper assembly.
[0003] (2) Description of the Related Art
[0004] Very often in the heating and cooling systems of structures, and in particular residential structures, the network of air ducts that supply heated or cooled air to the different structures are constructed in various different sizes. This at times will result in the duct openings that supply air through openings cut in the floors and walls of the structure to be of different sizes. This does not often occur in individual home constructions, but it can be found that homes constructed in different years or by different construction contractors will have air duct openings that are of different sizes. For example, air duct openings of 2.25″×10″, 2.25″×12″, 3″×10″, 4″×10″, 4″×12″, and 4″×14″ are common.
[0005] The existence of air duct openings of different sizes makes choosing a register assembly for an existing home, or supplying register assemblies for a home under construction difficult. Not only must a desirable design for the register faceplate be chosen, but care must be taken to ensure that the register assembly is properly sized to fit the particular duct opening of the home. This requires that the air duct openings be carefully measured, and the properly dimensioned register assembly be obtained to fit each air duct opening.
SUMMARY OF THE INVENTION
[0006] The register assembly with the adjustable faceplate connectors of the present invention overcomes the disadvantages associated with the different sized air duct openings of homes and other structures. The register assembly of the invention is comprised of a framed faceplate, a plurality of damper assemblies that are each dimensioned to fit the duct opening dimensions commonly used in building construction, and a plurality of connectors that are adjustably fit to the faceplate to enable the removable attachment of the faceplate to each of the different sized damper assemblies.
[0007] The one faceplate is dimensioned to cover the various different sizes of duct openings. The outer peripheral border of the faceplate is dimensioned sufficiently large to extend beyond the perimeter dimensions of each of the commonly used duct openings. One or more holes are provided through the faceplate to provide the free flow of air through the faceplate. A variety of different faceplates could be provided with the holes of the faceplate cut in a variety of different patterns.
[0008] A plurality of different damper assemblies are provided, each being dimensioned to match the damper assembly with a particular size of duct opening. Each damper assembly is constructed with a base having four side walls that surround a center opening through the base. Examples of damper assemblies are disclosed in the U.S. Patents of Berger U.S. Pat. No. 6,309,297 B1 and U.S. Pat. No. 6,506,113 B2, the disclosures of each patent being incorporated herein by reference. Each damper assembly base contains one or more louvers that are movable relative to the base to control the flow of air through the damper assembly.
[0009] The plurality of connectors are each adapted to attach the faceplate to each of the different sizes of damper assemblies. Each of the connectors are identical in construction, reducing their cost to manufacture. Each of the connectors are removably attachable to the faceplate and are removably attachable to each of the different sized damper assemblies without the use of separate fasteners. Thus, the entire register assembly can be assembled without separate threaded fasteners. The connectors are removably attachable to the faceplate in a variety of adjusted positions. In each of the adjusted positions of the connectors relative to the faceplate, the connectors adapt the faceplate for removable attachment to one of the various different sizes of damper assemblies.
[0010] Thus, for any particular duct opening, an appropriately dimensioned damper assembly is chosen. A faceplate is chosen that has a desirable pattern of openings. The damper assembly is assembled over the air duct opening. The plurality of connectors are then removably attached to the faceplate in a particular pattern of the connectors relative to the faceplate to enable the removable attachment of the faceplate to the chosen damper assembly. The damper assembly is then removably attached to the plurality of connectors, thereby removably attaching the damper assembly to the faceplate.
[0011] In the manner discussed above, the register assembly of the invention is inexpensively and easily assembled over air duct openings of various different sizes. Thus, the register assembly of the invention simplifies the assembly of the air heating and cooling system and reduces the number of different parts needed to assemble the system, thereby reducing the cost of the systems assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Further features of the invention are set forth in the following detailed description of the preferred embodiment of the invention and in the drawing figures wherein:
[0013] FIG. 1 is a top plan view of a framed faceplate of the register assembly of the invention;
[0014] FIG. 2 is a side elevation view of the faceplate of FIG. 1 ;
[0015] FIG. 3 is an end elevation view of the faceplate of FIG. 2 ;
[0016] FIG. 4 is a cross section of the faceplate taken along the line 4 - 4 of FIG. 1 ;
[0017] FIG. 5 is a cross section of the faceplate along the line 5 - 5 of FIG. 1 ;
[0018] FIG. 6 is a top plan view of one of the plurality of connectors of the invention;
[0019] FIG. 7 is a side elevation view of the connector;
[0020] FIG. 8 is an end elevation view of the connector;
[0021] FIG. 9 is a cross-section of the connector along the line 9 - 9 of FIG. 6 ;
[0022] FIG. 10 is a partial view of the one of the connectors mounted in one of its adjusted positions relative to the faceplate;
[0023] FIG. 11 is a partial side view of the connector and faceplate shown on FIG. 10 ;
[0024] FIG. 12 is a partial view of the faceplate and one of the connectors in a second adjusted position of the connector; and
[0025] FIG. 13 is a partial side view of the faceplate and connector of FIG. 12 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] The register assembly of the invention is designed to be used with a damper assembly of the type disclosed in the U.S. Patents of Berger U.S. Pat. No. 6,309,297 B1 and U.S. Pat. No. 6,506,113 B2, the disclosures of both being incorporated herein by reference. As stated earlier, damper assemblies of this type are provided in a variety of different sizes to fit different size air duct openings. A common feature of each of the different damper assemblies is that they include a plurality of pawl projections that each project inwardly from an interior surface of the damper base. Each of the projections is positioned to receive a tab of a faceplate that is being removably attached to the damper assembly. Because the constructions of these damper assemblies are known in the art as shown in the above-referenced patents, they are not described in further detail here or shown in the drawing figures.
[0027] The register assembly of the invention is basically comprised of a framed faceplate 12 and a plurality of connectors 14 that are removably attachable to the faceplate and to an associated damper assembly. Each of the faceplate 12 and connectors 14 may be constructed from a variety of different materials such as metals, wood, or plastic. It is only desirable that the particular materials used to construct the faceplate 12 and connectors 14 have a certain degree of resilience to enable component parts of the connectors 14 to resiliently flex relative to each other, as will be explained.
[0028] As seen in FIG. 1 , the faceplate 12 has a rectangular configuration that is dimensioned to cover over the floor or wall opening associated with an air duct opening with which the register assembly of the invention is to be used. The faceplate 12 is designed with a framed border area 16 that extends around the top surface of the faceplate and defines the peripheral edge 18 of the faceplate. The outer dimensions of the faceplate peripheral edge 18 are also dimensioned sufficiently large so that the faceplate 12 will cover over each of the different sizes of damper assemblies available. A plurality of openings 20 are formed in the faceplate inside the border area 16 . As shown in FIG. 1 , the openings 20 are typically designed to have an aesthetically pleasing appearance. A variety of different patterns of openings 20 could be provided in a plurality of different faceplates.
[0029] As shown in FIGS. 2-5 , the framed border 16 of the faceplate 12 is positioned on an upper portion of the faceplate. The faceplate also has a lower portion defined by sidewalls 22 , 24 , 26 , 28 that are positioned inwardly from the faceplate peripheral edge 18 and below the framed border 16 of the faceplate. The positions and dimensions of the faceplate sidewalls 22 , 24 , 26 , 28 are determined to enable the sidewalls to be inserted into an opening cut in a floor or wall for an air duct opening. With sidewalls 22 , 24 , 26 , 28 inserted into the floor or wall opening, the framed border 16 of the faceplate conceals the opening.
[0030] A plurality of notches 34 are recessed into the elongated faceplate sidewalls 22 , 24 . Notches could also be provided in the shorter sidewalls 26 , 28 . Each of the notches 32 has a back wall 34 and a pair of opposed walls 36 that define the interior of the notch. Opposed, projecting tongues or ribs 38 project outwardly from the opposed walls 36 of each notch. The tongues 38 extend along the length of the opposed walls 36 to the notch back wall 34 . In the particular embodiment of the faceplate 12 shown in the drawing figures, there are four notches 32 .
[0031] FIGS. 6-9 show the construction of each of the connectors 14 used with the faceplate 12 of the invention. With the faceplate 12 having four notches 32 , the register assembly of the invention will make use of four connectors 14 . For different numbers of notches, different numbers of connectors are used. All of the connectors 14 used with each faceplate 12 are the same in construction.
[0032] Each connector 14 is basically constructed with a first portion 42 and a second portion 44 that are oriented at an angle relative to each other. In the preferred embodiment the two portions 42 , 44 define a right angle.
[0033] As shown in FIG. 6 , the first portion 42 of the connector 12 has a rectangular configuration defined by a pair of opposite sidewalls 48 and a front wall 50 and opposite back wall 52 . The first portion 42 also has a top surface 54 and an opposite bottom surface 56 . An opening 58 extends through the connector first portion 42 from the top surface 54 to the bottom surface 56 . The rectangular configuration of the connector first portion 42 is dimensioned to fit into each notch 32 of the faceplate 12 with the connector first portion sidewalls 48 opposing the notch opposed walls 36 .
[0034] As seen in FIG. 7 , each of the connector sidewalls 48 is provided with a groove 62 that extends through the sidewall. The grooves 62 are dimensioned to receive the notch tongues 38 that project from the opposed walls 36 of the faceplate notches 32 . Engagement of the faceplate tongues 38 in the connector grooves 62 holds the connector in the faceplate notch 32 .
[0035] The connector first portion 42 is dimensioned to be received in each faceplate notch 32 in two positions of the connector relative to the notch. In the first position of the connector 14 relative to the faceplate notch 32 , the back wall 52 of the connector first portion is positioned against the notch back wall 34 with the notch tongues 38 positioned in the connector groove 62 . In the second position of the connector 14 relative to the faceplate notches 32 , the front wall 50 of the connector first portion is positioned against the notch back wall 34 with the notch tongues 38 positioned in the connector grooves 62 . In each of the first and second positions of the connector 14 relative to the faceplate 12 , the connectors 14 are removably attached to the faceplate 12 without the use of separate fasteners, for example screw-threaded screw and nut fasteners.
[0036] Each second portion 44 of each connector 14 projects outwardly from the first portion bottom surface 56 adjacent the first portion front wall 50 . As seen in FIGS. 6 and 7 , each second portion 44 has a general rectangular configuration with a pair of opposite sidewalls 64 and a front wall 66 and opposite back wall 68 . Both the front wall 66 and back wall 68 have respective tapered portions 72 , 74 at the lower ends of the walls, as best seen in FIGS. 8 and 9 . An opening 76 also passes through the connector second portion 44 from the front wall 66 to the back wall 68 . The opening 76 gives the connector second portion 44 a certain resilience that enables the second portion 44 to be resiliently flexed relative to the first portion 42 . The openings 76 are dimensioned to receive the projections or pawls of the damper assemblies described in the earlier referenced patents. As stated earlier, each connector 14 can be removably attached to the framed faceplate 12 in a first and second position of the connector relative to the faceplate. This adapts the faceplate 12 for removable attachment to damper assemblies of different sizes. FIG. 11 shows a partial, side sectioned view of a connector 14 inserted in a notch 32 of the faceplate 12 in the first position of the connector relative to the faceplate. It can be seen that in the first position of the connector 14 , the connector second portion 44 is positioned outwardly to its greatest extent relative to the faceplate peripheral edge 18 . With all of the four connectors 14 removably attached to the faceplate 12 in their first relative positions as shown in FIG. 11 , the faceplate 12 is adapted for removable attachment to the larger damper assembly construction.
[0037] FIG. 13 shows a partial, side sectioned view of a connector 14 removably attached in a notch 32 of the faceplate 12 in the second relative position of the connector 14 to the faceplate. In the second position of the connector 14 relative to the faceplate 12 , the connector second portion is positioned radially inwardly from the faceplate peripheral edge 18 to its greatest extent, as shown in FIG. 13 . This adapts the faceplate 12 for removable attachment to a damper assembly of the smaller size. Each of the second portions 44 of the connectors attached to the faceplate 12 in the relative positions shown in FIG. 13 are positioned to be inserted inside the side walls of the damper assembly base in attaching the faceplate to the damper assembly.
[0038] In removably attaching the framed faceplate 12 with the removably attached connectors 14 to a damper assembly, the faceplate is first positioned over the damper assembly of the appropriate size, i.e., a larger or smaller damper assembly, with the connector second portions 44 positioned just above the projections on the interior surfaces of the damper assembly side walls. The faceplate 12 and attached connectors 14 are then moved downwardly toward the damper assembly inserting the four connector second portions 44 inside the damper assembly side walls. The tapered portions 72 of the front walls 66 of the connector second portions slide over the projections or pawls of the damper assembly causing the connector second portions 44 to resiliently flex inwardly relative to the first portions 42 and the faceplate 12 . When the tapered portions 72 pass over the damper assembly projections, the connector second portions 44 snap back into their original positions relative to the first portions 42 as shown in FIGS. 8 and 9 , with the damper assembly projection being received in the connector second portion opening 76 . In this way, the connector second portion opening 76 acts as a recess that receives the damper assembly projection to removably attach each connector 14 to the damper assembly projection, and removably attach the faceplate 12 to the damper assembly.
[0039] Although the present invention has been described above by reference to specific embodiments, it should be understood that modifications and variations of the invention may be constructed without departing from the scope of the invention defined in the following claims.
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A register assembly with adjustable faceplate connectors can be used to cover air duct openings that supply a flow of heated or cooled air to a room of a structure, and can also be used to cover air duct openings that receive return air from the room. The register assembly includes a faceplate that has removably attachable connectors that adapt the faceplate to be removably attached to a plurality of damper assemblies of different sizes. The plurality of connectors are adjustably connected to the faceplate to adapt the faceplate to each different size of damper assembly.
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[0001] This Application is a divisional application of pending U.S. patent application Ser. No. 10/322,531, filed on Dec. 19, 2002, the disclosure of which is expressly incorporated herein by references in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a scanning optical system employed in an optical scanning unit for a laser beam printer or the like.
[0003] Typically, a scanning optical system is configured such that a laser beam emitted by a laser diode is deflected by a polygonal mirror to scan within a predetermined angular range. The scanning laser beam is converged by an fθ optical system on an object (which is generally a photoconductive surface) to be scanned, thereby a beam spot being formed on the object to be scanned. The beam spot on the object moves as the polygonal mirror rotates. By ON-OFF modulating the laser beam, an electrostatic latent image is formed on the photoconductive surface. In this specification, a direction where the beam spot moves on the object is referred to as a main scanning direction, and a direction perpendicular to the main scanning direction on the object surface will be referred to as an auxiliary scanning direction. In the following description, a shape and a power of each optical element will be described with reference to the directions on the object. For example, if an element is described to have a refraction power in the main scanning direction, whichever direction the element may be oriented, the power affects the beam spot in the main scanning direction on the object.
[0004] The scanning optical system is generally designed such that an optimum performance is achieved at a single design wavelength. A laser diode employed in such a scanning optical system is a single mode laser diode which emits a beam having a single wave length.
[0005] The single mode laser diode employed as a laser source of a conventional scanning optical system is more expensive than a multi-mode laser diode, which emits a beam having a plurality of peak wavelengths. Therefore, there has been a desire for making use of the multi-mode laser diode as the laser source so as to reduce a manufacturing cost.
[0006] The conventional scanning optical system is, however, designed on assumption of using a single wavelength as described above, and is not configured to compensate for lateral chromatic aberration. Therefore, if the multi-mode laser diode is used for the conventional scanning optical system, a size of the beam spot scanning on the photoconductive drum expands and thus a dot size of an image formed thereon is enlarged, which deteriorates a quality of the formed image.
[0007] It is apparent that if the optical system is configured such that the lateral chromatic aberration is compensated, the above problem does not occur even if the multi-mode laser diode is used. However, in order to compensate for the lateral chromatic aberration, a plurality of lenses made of different materials having different dispersions should be used. In such a configuration, even though the cost for the light source is reduced by replacing the single mode laser diode with a multi-mode laser diode, the entire cost of the optical system increases since the cost of the fθ lens increases.
SUMMARY OF THE INVENTION
[0008] The present invention is advantageous in that an improved scanning optical system is provided with which the manufacturing cost of the entire optical system can be reduced with employing the multi-mode laser diode as a light source.
[0009] According to an aspect of the invention, there is provided a scanning optical system, which is provided with a light source including a multi-mode laser diode emitting a laser beam, a polygonal mirror that deflects the laser beam emitted by the light source, and an fθ optical element that has positive power both in a main scanning direction and in an auxiliary scanning direction, the fθ optical element converging the laser beam deflected by the polygonal mirror to converge on an object to be scanned. In this scanning optical system, the fθ optical element is configured to have a reflection surface, the power of the fθ optical element in the main scanning direction being provided mainly by the reflection surface.
[0010] Since the power in the main scanning direction of the fθ optical element is mainly provided by the reflection surface, the lateral chromatic aberration can be well suppressed. Thus, with this configuration, the multi-mode laser diode can be used as the light source and a sufficient beam size can be achieved without increasing the manufacturing cost of the fθ optical element.
[0011] Optionally, the fθ optical element may include an element made of light transmissive material, the element having a first surface that transmits light and a second surface that reflects the light that enters into the element from the first surface.
[0012] Still optionally, the polygonal mirror and the fθ optical element are arranged such that the beam incident on the polygonal mirror and the beam deflected by the polygonal mirror forms a certain angle in the auxiliary scanning direction and that the beam incident on the fθ optical element and the beam reflected by the fθ optical element forms a certain angle in the auxiliary scanning direction.
[0013] According to another aspect of the invention, there is provided a scanning optical system which is provided with a light source including a multi-mode laser diode emitting a laser beam, a polygonal mirror that deflects the laser beam emitted by the light source, and an fθ lens that converges the laser beam deflected by the polygonal mirror on an object to be scanned. With this structure, the fθ lens is configured to include at least one refractive lens and a diffractive lens structure formed on at least one surface of the at least one refractive lens, the diffractive lens structure being configured to compensate for chromatic aberrations provided by refractive lens structure of the fθ lens.
[0014] With the above configuration, the multi-mode laser diode can be used as the light source without increasing the manufacturing cost of the fθ optical system.
[0015] Optionally, a central axis of the laser beam incident on the polygonal mirror and an optical axis of the fθ lens are on a same plane and form a predetermined angle.
[0016] According to a further aspect of the invention, there is provided a scanning optical system which is provided with a light source including a multi-mode laser diode emitting a laser beam, a polygonal mirror that deflects the laser beam emitted by the light source, and an fθ optically system that converges the laser beam deflected by the polygonal mirror on an object to be scanned, the fθ lens being configured to suppress lateral chromatic aberration. In particular, the lateral chromatic aberration is suppressed by employing at least one of (a) a reflection surface having a predetermined power in the main scanning direction and (b) a diffractive lens structure that compensates for chromatic aberrations provided by a refractive lens structure of the fθ lens.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0017] FIG. 1 a perspective view of a scanning optical system according to a first embodiment of the invention;
[0018] FIG. 2 is a view, taken along a plane perpendicular to an auxiliary scanning direction, of the scanning optical system according to the first embodiment;
[0019] FIG. 3 is a view, taken along a plane perpendicular to a main scanning direction, of the scanning optical system according to the first embodiment;
[0020] FIGS. 4A-4C are graphs indicating an fθ error, curvature of field and lateral chromatic aberration of the scanning optical system according to the first embodiment;
[0021] FIG. 5 is a view, taken along a plane perpendicular to an auxiliary scanning direction, of a scanning optical system according to a second embodiment;
[0022] FIGS. 6A and 6B are side and front view of a first lens of an fθ lens employed in the scanning optical system according to the second embodiment; and
[0023] FIGS. 7A-7C are graphs indicating an fθ error, curvature of field and lateral chromatic aberration of the scanning optical system according to the second embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0024] Hereinafter, scanning optical systems according to two embodiments of the invention will be described with reference to accompanying drawings.
[0025] According to the embodiments, the scanning optical systems are to be employed in an exposure unit of a laser beam printer. The exposure unit emits a scanning laser beam which is ON-OFF modulated in accordance with an input image signal to the photoconductive drum to form an electrostatic latent image thereon.
[0026] First Embodiment
[0027] FIG. 1 a perspective view of a scanning optical system 100 according to a first embodiment of the invention. The scanning optical system 100 employs a multi-mode laser diode 10 . The laser diode 10 emits a diverging laser beam, which is collimated by a collimating lens 20 . The collimated laser beam is incident on an anamorphic lens 30 , which has a relatively strong positive power in the auxiliary scanning direction and a relatively week negative power in the main scanning direction. The laser beam passed through the anamorphic lens 30 is reflected by a planar mirror 31 and incident on the polygonal mirror 50 with a certain angle in the auxiliary scanning direction (see FIG. 3 ).
[0028] The beam incident on the polygonal mirror 50 is reflected by reflection surfaces 51 thereof with a first separation angel a in the auxiliary scanning direction. The reflected laser beam is incident on the fθ optical element 40 . The fθ optical element 40 is formed of transparent material having a first surface 41 which allows the beam to pass therethrough, and a second surface 42 which reflects the beam incident from the first surface 41 on its inner surface. The beam reflected by the inner surface of the second surface 42 passes through the first surface 41 again, and exits therefrom.
[0029] The second surface 42 is formed with a reflection coating of silver or aluminum by deposition so that the beam is reflected on its inner surface. The first surface 41 and the second surface 42 incline macroscopically with respect each other in the auxiliary scanning direction.
[0030] The laser beam exiting from the fθ optical element 40 proceeds toward the polygonal mirror 50 with a second separation angle β in the auxiliary scanning direction between the incident beam and the exiting beam. The beam passes above the polygonal mirror in FIG. 1 , and forms a beam spot, which scans in the main scanning direction that is parallel with a generatrix of a cylindrical shape of the photoconductive drum 60 .
[0031] It should be noted that the positive power of the fθ optical element 40 in the main scanning direction is mainly provided by the second surface 42 which is the reflection surface. Accordingly, the lateral chromatic aberration is well suppressed, and the beam emitted by the multi-mode laser diode 10 can be sufficiently converged to form a beam spot having a sufficiently small size.
[0032] FIG. 2 is a view, taken along a plane perpendicular to an auxiliary scanning direction, of the scanning optical system according to the first embodiment. FIG. 3 is a view, taken along a plane perpendicular to a main scanning direction, of the scanning optical system according to the first embodiment.
[0033] In each of FIGS. 2 and 3 , a structure of the scanning optical system from the anamorphic lens 30 to the photoconductive drum 60 is shown. In FIG. 2 , the laser diode 10 and the collimating lens 20 are also shown. It should be noted that, in FIG. 2 or 3 , a mirror 31 is omitted from the drawing, and an optical path between the anamorphic lens 30 and the polygonal mirror 50 is indicated as a developed path.
[0034] TABLE 1 indicates a concrete example of the scanning optical system according to the first embodiment of the invention. In the table, α denotes the first separation angle, β denotes the second separation angle, ry denotes radius of curvature of each surface in the main scanning direction, rz denotes radius of curvature of each surface in the auxiliary scanning direction (indication thereof will be omitted where the surface is a rotationally symmetrical one), d denotes a distance between adjoining surfaces on the optical axis, and n denotes a refractive index at a wavelength of 780 nm.
[0035] Surface numbers indicated in the table are assigned to the surfaces of the optical elements in the order where the laser beam proceeds. That is, surfaces #1 and #2 represent surfaces of the anamorphic lens 30 , surface #3 represents the mirror surfaces 51 of the polygonal mirror 50 , surface #4 represents the first surface 41 of the fθ optical system 40 , surface #5 represents the second surface 42 of the fθ optical system 40 , and surface #6 represents the first surface 41 of the fθ optical system 40 (i.e., surfaces #4 and #6 indicate the same surface).
TABLE 1 scanning coefficient: 135.5 α = 10.0° β = 8.0° Surface ry rz d n #1 −72.000 55.424 2.000 1.48617 #2 ∞ — 113.000 #3 ∞ — 50.000 #4 −265.075 ∞ 5.000 1.48617 #5 −231.860 TABLE 3 5.000 1.48617 #6 −265.075 ∞ 160.035
[0036] The first surface 41 (i.e., surfaces #4 and #6) is an anamorphic aspherical surface which is not a rotationally symmetrical surface. The shape of the first surface 41 along the main scanning direction is expressed by a SAG X(Y) which is a function of a coordinate Y in the main scanning direction.
X ( Y ) = Y 2 r ( 1 + 1 - ( κ + 1 ) Y 2 r 2 ) + ∑ AMpY p ( 1 )
where, it is assumed that the shape in the main scanning direction passes a predetermined origin, and Y is a coordinate, with respect to the origin, of a point on the first surface 41 along the main scanning direction, X(Y) is a SAG amount which represents a distance of the point on the first surface 41 with respect to a plane tangential to the first surface 41 at the origin, r represent a radius of curvature at the origin, κ represents a conical coefficient and AMp is a p-th order aspherical coefficient (p being an integer).
[0037] The shape of the first surface 41 in the auxiliary scanning direction is an arc, whose curvature Cz(Y) at a coordinate Y in the main scanning direction is expressed by equation (2):
Cz ( Y )= Czo+ΣASqY q (2)
where, Czo is a curvature in the auxiliary scanning direction on the origin, and ASq represents a q-th order curvature coefficient.
[0038] The values of the coefficients AMp and ASq for equations (1) and (2) are indicated in TABLE 2.
[0039] It should be noted that the radius of curvature in the auxiliary scanning direction at the origin of the first surface 41 is infinity, and therefore, the curvature Czo is zero. Further, since the values for odd order of AMp and ASq are zero, TABLE 2 indicates the values for even order thereof. As understood from the equations, the first surface 41 is symmetrical in the main scanning direction with respect to the origin, and also symmetrical in the auxiliary scanning direction with respect to the origin since the shape in the auxiliary scanning direction is an arc.
TABLE 2 MAIN SCANNING AUXILIARY SCANNING DIRECTION DIRECTION κ 0.0 — AM2 9.57071 × 10 −04 AS2 3.32077 × 10 −08 AM4 −6.81320 × 10 −11 AS4 −1.02051 × 10 −11 AM6 −3.84519 × 10 −11 AS6 −5.96555 × 10 −15 AM8 −9.94042 × 10 −18 AS8 1.46273 × 10 −16 AM10 −5.33698 × 10 −21 AS10 0.0 AM12 −1.13355 × 10 −24 AS12 0.0
[0040] The second surface 42 (surface #5) of the fθ optical element 40 is expressed by a SAG X(Y, Z) which is a function of Y and Z coordinates, where Y is a height of a point on the second surface 42 in the main scanning direction with respect to an origin and Z is a height of the point in the auxiliary scanning direction.
X ( Y , Z ) = Y 2 + Z 2 r ( 1 + 1 - ( κ + 1 ) ( Y 2 + Z 2 ) r 2 ) + ∑ B mn Y m Z n ( 3 )
where, the SAG X(Y,Z) represents a distance of the point on the second surface 42 with respect to an imaginary reference plane, r is a radius of curvature of the surface at the origin, κ is a conical coefficient and Bmn is a coefficient.
[0041] Each of the reference plane referred to for defining the second surface 42 and the tangential plane referred to when defining the first surface 41 is perpendicular to a predetermined reference axis, and intersection point of the reference axis and each of the first and second surfaces 41 and 42 is defined as the origin for each surface.
[0042] The values of the coefficients Bmn are indicated in TABLE 3. It should be noted that, in the auxiliary scanning direction, coefficients Bmn for terms having only a first-order component (i.e., odd-order terms) have values other than zero. Therefore, the second surface 42 is inclined, in the auxiliary scanning direction, with respect to the reference plane. In the main scanning direction, the coefficients Bmn for odd-order terms are zero, and therefore, the second surface 42 is symmetrical, in the main scanning direction, with respect to the origin.
[0043] TABLE 3 includes values for odd numbers of n, but does not include values for odd number of m since they are zero.
TABLE 3 Bmn n = 0 n = 1 n = 2 n = 3 n = 4 m = 0 0.0 −4.7676 × 10 −02 −1.9823 × 10 −03 −2.6829 × 10 −06 1.6459 × 10 −06 m = 2 2.9399 × 10 −04 3.0589 × 10 −06 2.0803 × 10 −07 −1.8380 × 10 −09 −3.9318 × 10 −12 m = 4 3.9253 × 10 −08 4.4950 × 10 −10 −2.8244 × 10 −11 4.6055 × 10 −13 −1.6421 × 10 −13 m = 6 −1.6234 × 10 −11 −5.9046 × 10 −10 2.1719 × 10 −14 −8.1058 × 10 −16 −4.4493 × 10 −17 m = 8 1.0587 × 10 −15 2.1083 × 10 −11 9.7026 × 10 −18 4.8969 × 10 −19 1.6297 × 10 −20 m = 10 −5.8655 × 10 −19 −3.1655 × 10 −20 3.4090 × 10 −21 0.0 0.0 m = 12 8.2703 × 10 −23 0.0 0.0 0.0 0.0
[0044] The tangential plane to the first surface 41 and the reference plane for the second surface 42 are parallel to each other, and are perpendicular to the same reference axis. The first surface 41 does not incline with respect to the tangential plane, while the second surface 42 inclines, in the auxiliary scanning direction, with respect to the reference plane. Therefore, macroscopically, the first surface 41 and the second surface 42 are inclined with respect to each other in the auxiliary scanning direction.
[0045] FIGS. 4A-4C are graphs indicating an fθ error, curvature of field (broken line: main scanning direction; solid line: auxiliary scanning direction) and lateral chromatic aberration (wavelength difference: 2 nm) of the scanning optical system 100 according to the first embodiment. In each graph, the vertical axis represents an image height (i.e., a distance in the main scanning direction with respect to the center of a scanning range on the photoconductive drum), and the horizontal axis represents the quantity of aberration (unit: mm). Since the power in the main scanning direction is achieved mainly by the reflection surface, the lateral chromatic aberration is well suppressed.
[0046] Second Embodiment
[0047] FIG. 5 is a view, taken along a plane perpendicular to an auxiliary scanning direction, of a scanning optical system 200 according to a second embodiment.
[0048] Similarly to the first embodiment, the scanning optical system 200 employs the multi-mode laser diode 10 and the collimating lens 20 . The laser beam collimated by the collimating lens 20 is incident on a cylindrical lens 32 which has a positive power only in the auxiliary scanning direction. The laser beam passed through the cylindrical lens 32 is deflected by the polygonal mirror 50 and incident on an fθ lens 70 , which converges the laser beam on the photoconductive drum 60 to form a beam spot thereon. According to the second embodiment, the central axis of a beam incident on the polygonal mirror 50 and the optical axis of the fθ lens are on the same plane and form a predetermined angle. With this configuration, the amount of bow generated by the fθ lens can be reduced. In contrast to the second embodiment, according to the structure of the first embodiment, the size of the scanning optical system can be made smaller.
[0049] The fθ lens 70 includes a first lens 71 located on the polygonal mirror side and a second lens 72 located on the photoconductive drum side. Further, a polygonal mirror side surface of the first lens 71 is formed with a transmissive diffraction surface DIF.
[0050] FIG. 6A is a side view of the first lens 71 , and FIG. 6B is a front view, viewed from the polygonal mirror side, of the first lens 71 .
[0051] As shown in FIG. 6A , the diffraction lens structure DIF has steps whose pitch is smaller at an outer portion thereof. The boundaries of the steps are, when viewed from the polygonal mirror side, formed to be a part of concentric circles as shown in FIG. 6B .
[0052] It should be noted that FIGS. 6A and 6B show exaggerated view, where the number of steps are less than the actual number, and the height of steps are larger than the actual height for the sake of brevity.
[0053] The fθ lens 70 has a simple structure consisting of only two refractive lenses. However, by forming the diffractive lens structure DIF, the lateral chromatic aberration is well compensated, the laser beam emitted by the multi-mode laser diode can be converged to a necessary size. An example of the diffractive lens structure employed in a scanning optically system and compensates for the lateral chromatic aberration is disclosed in U.S. Pat. No. 6,259,547, the teachings of which are incorporated herein by reference.
[0054] TABLE 4 indicates the numerical structure of the scanning optical system 200 . In the TABLE 2, surfaces #1 and #2 represent the cylindrical lens 32 , surface #3 represents the reflection surface 51 of the polygonal mirror 50 , surfaces #4 and #5 represent the fist lens 71 and surfaces #6 and #7 represent the second lens 72 of the fθ lens 70 . The focal length of the diffraction lens surface DIF is 5089.159 mm.
TABLE 4 scanning coefficient: 200.000 Surface ry rz d n #1 ∞ 55.424 2.00 1.48617 #2 ∞ — 97.00 #3 ∞ — 40.00 #4 −153.034 — 8.50 1.48617 #5 −61.827 — 110.00 #6 −497.023 31.077 5.00 1.48617 #7 −497.950 — 90.00
[0055] The polygonal mirror side surface (#4) of the first lens 71 is configured such that the diffraction lens structure DIF is formed on a spherical base curve. The other surface (#5) of the first lens 71 is a rotationally symmetrical aspherical surface.
[0056] The rotationally symmetrical aspherical surface is expressed by a SAG X(h) which represents a distance from a plane tangential to the rotationally symmetrical aspherical surface at the optical axis thereof to a point thereon, whose height with respect to the optical axis is h. The SAG X(h) is expressed by the following equation.
X ( h ) = h 2 r ( 1 + 1 - ( κ + 1 ) h 2 r 2 ) + ∑ A p h p ( 4 )
where, κ is a conical coefficient, r is a radius of curvature of the aspherical surface at the optical axis, and Ap is an aspherical coefficient for p-th order term.
[0057] The values of κ and Ap are indicated in TABLE 5.
TABLE 5 κ 0.00000 A4 2.07880 × 10 −07 A6 −2.92095 × 10 −11 A8 2.10239 × 10 −14
[0058] The polygonal mirror side surface (#6) of the second lens 72 is an anamorphic aspherical surface, which is similar to the first surface (#4 and #6) of the fθ optical element 41 of the first embodiment, and is expressed by the equations (1) and (2). The values of the coefficients defining the surface #6 are indicated in TABLE 6.
TABLE 6 MAIN SCANNING AUXILIARY SCANNING DIRECTION DIRECTION κ 0.0 — AM2 0.0 AS2 −2.56679 × 10 −06 AM4 1.07453 × 10 −07 AS4 −8.41951 × 10 −07 AM6 −5.45956 × 10 −12 AS6 5.51026 × 10 −12 AM8 2.14629 × 10 −16 AS8 6.98197 × 10 −16
[0059] The surface #7 of the second lens 72 is a spherical surface.
[0060] FIGS. 7A-7C are graphs indicating an fθ error, curvature of field (broken line: main scanning direction; solid line: auxiliary scanning direction) and lateral chromatic aberration (wavelength difference: 2 nm) of the scanning optical system 200 according to the second embodiment. In each graph, the vertical axis represents an image height (i.e., a distance in the main scanning direction with respect to the center of a scanning range on the photoconductive drum), and the horizontal axis represents the quantity of aberration (unit: mm). With use of the diffraction lens structure DIF, the lateral chromatic aberration is well suppressed.
[0061] The present disclosure relates to the subject matter contained in Japanese Patent Application No. 2001-388124, filed on Dec. 20, 2001, which is expressly incorporated herein by reference in its entirety.
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A scanning optical system includes a light source including a multi-mode laser diode that emits a laser beam, and a polygonal mirror that deflects the laser beam emitted by the light source. An fθ lens converges the laser beam deflected by the polygonal mirror on an object to be scanned. The fθ lens includes at least one refractive lens and a diffractive lens structure formed on at least one surface of the at least one refractive lens, the diffractive lens structure being configured to compensate for chromatic aberrations provided by a refractive lens structure of the fθ lens.
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The present invention relates to an optical information storage medium having a large memory capacity in which the temperature of an active recording layer is controllably elevated by optical irradiation, thereby causing structural phase changes or atomic rearrangements in the active layer by which the information is either recorded or erased.
BACKGROUND OF THE INVENTION
Optical recording discs in the prior art include non-erasable write-once systems which utilize as the active recording layer a TeO x (0<×<2.0) thin film formed from Te and TeO 2 . Erasable discs have also been reported and are being developed for practical applications in which it is possible to repeatedly write and erase information by optical means. In such erasable optical discs, a thin film layer of material is typically heated and melted by laser light, then rapidly cooled so that its structure is in a substantially non-crystalline or amorphous state, thereby recording information which is indicated by the optical properties of the substantially non-crystalline or amorphous state. The recorded information can be subsequently erased by heating the active layer, and then slowly cooling it so that its atomic structure anneals and transforms into a substantially crystalline state, having different optical properties from that of the amorphous state, which indicate thereby an erased condition.
Materials investigated as active layers for erasable discs which operate via a phase change mechanism involving an amorphous/crystalline transition include various combinations of the chalcogen elements as exemplified by Ge 15 Te 81 Sb 2 S 2 . Such combinations have been studied by Ovshinsky et. al and Feinleib et al. (see Appl. Phys. Lett., vol. 18 (1971)). In addition, thin film active layers consisting of combinations of a chalcogen element or elements with an element or elements chosen from Group V of the periodic table or an element or elements chosen from Group IV of the periodic table, e.g. Ge, As 2 S 3 , As 2 Se 3 or Sb 2 Se 3 are known and have been studied in the prior art.
It is possible to produce an optical disc having thin film active layers on a substrate in which grooves are formed for the purpose of guiding the laser light. With respect to the utilization of such optical disc for the recording and erasing of information by laser light, the active layer is generally crystallized in advance, and a laser beam focused to a spot size of about 1 micron is intensity modulated between a peak power level and a lower bias power level with the recorded information. For example, a circular recording disk may be rotated and irradiated during rotation with pulses of laser light having a peak power sufficient to increase the temperature of the irradiated areas on the active layer above the melting point of the layer. If the irradiated areas are permitted to cool rapidly, the information will be recorded by the formation of substantially non-crystalline or amorphous marks at the locations of the irradiated areas.
Amorphous areas of the disc which are irradiated with the lower bias power level of the laser light can have the temperature in those areas elevated above the crystallization temperature of the active layer, in which case the active layer at those irradiated areas will be transformed back into a substantially crystalline structure, and the recorded information will thereby be erased, making it possible to over-write information. In this manner, areas on the active layer may be repeatedly cycled above the melting point thereof to produce recorded amorphous areas, or above the crystallization temperature thereof to produce crystalline erased areas, thereby effectuating the recording or overwriting of binary information.
Typically, the active layer in an optical disc is sandwiched between dielectric layers which have excellent heat resistance characteristics. These dielectric layers serve to contain the active layer and to protect a substrate and an adhesive layer from undergoing large changes in temperature during irradiation. Since the thermal behavior of the active layer, both as to it its ability to rapidly increase in temperature, as well as its rapid cooling and slow cooling characteristics, depend on the thermal conductivity of these dielectric layers, it is possible to optimize the recording and erasing characteristics by properly choosing the materials of the dielectric layers and by carefully controlling the thickness and composition of these layers.
Important design parameters which must be considered in developing and optimizing an erasable over-write optical recording medium are the erasability of the medium and the cyclability of the recording and erasing characteristics over many write/erase cycles.
With regard to the cyclability characteristics, studies have shown that there is a deterioration after a large number of write/erase cycles which results from thermal damage to the disc substrate or protective layer and which is manifested as an increase in noise. Further, studies have also shown that even in the absence of such thermal damage, a shift or physical distortion of the active layer along the direction of rotation of the disc may occur after many write/erase cycles as a result of thermally induced stress and distortion of the protective dielectric layers induced by the repeated heating and cooling cycles (see SPIE Optical Data Storage Topical Meeting, vol. 1078, p.27, Ohta et al.).
With regard to the erase characteristics, the melting point of non-crystalline films containing Te typically covers a wide temperature range of 400° C. to 900° C. As explained above, crystallization may be achieved by irradiating the active layer with laser light to increase its temperature, followed by a gradual cooling. The required temperature is generally within a range close to the crystallization temperature of the material, which is less that the melting point. When the crystallized film is irradiated with laser light having a higher power and is heated above the melting point, the film, upon rapid cool down, becomes substantially non-crystalline or amorphous, and an optically detectable mark is formed.
If the amorphous state is selected to represent the recorded condition, it is known that a more rapid cooling results in a more uniform amorphous state and results in a mark which produces a better and more stable signal. (See "Phase Change Disk Media Having Rapid Cooling Structure, Ohta et al., Jap. J. Appl. Phys. vol 28, 123 (1989)). These studies have shown that when the rate of cooling is too low, there arises a difference in the degree of non-crystallinity between the center of the mark and the periphery of the mark. During erasure, the mark is recrystallized. If the recorded mark is non-uniform in structure, the crystallization which occurs during subsequent erasure will be rendered non-uniform as well, resulting in a recording medium with less than optimum erasure characteristics.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved optical recording medium having an active recording thin film layer which can be rendered substantially non-crystalline or amorphous upon absorption of laser light energy, whereby a melting and rapid cooling of the active layer is produced; and which can be rendered substantially crystalline by heating the amorphous layer above the crystallization temperature.
It is a further object of the present invention to provide an erasable optical information recording medium with improved over-write cyclability characteristics and improved laser power dependence characteristics.
It is yet a further object of the present invention to provide an optical recording medium which has improved thermal characteristics, and improved long term stability with respect to thermal stress and deterioration induced by many write/erase cycles.
A still further object of the present invention is to provide a process for manufacture of an erasable optical information recording medium having such improved characteristics.
Accordingly, there is provided an optical recording medium having an active layer which is capable of absorbing energy and being converted between a substantially non-crystalline amorphous state and a substantially crystalline state, wherein the active layer includes nitrogen. The optical recording medium generally comprises a structure which includes a substrate, a first dielectric layer formed on one surface of the substrate, an active layer formed on top of the first dielectric layer wherein the active layer includes nitrogen, a second dielectric layer formed on top of the active layer, and a reflecting layer formed on top of the second dielectric layer. The active layer may be formed by incorporation of nitrogen into a chalcogenide composition of Ge, Te, and Sb The nitrogen may be incorporated as a nitride of one of the chalcogen elements, or may form a nitrided surface layer on the chalcogen composition. The active layer may be produced by sputtering a target in a nitrogen containing rare gas mixture, or by sputtering a target which includes a nitride composition.
As explained, one of the factors which contributes to the deterioration of the recording and erasing characteristics after many write/erase cycles is a localized shift of the material in the active layer. To prevent or reduce the tendency for this shift to occur, in the present invention, nitrogen or a nitride substance is incorporated in the active layer or on its surface.
Furthermore, the optical recording medium which incorporates this active recording layer sandwiches the recording layer between a first dielectric layer formed on one side of a transparent substrate, and a second dielectric layer. The second dielectric layer has a metallic reflecting layer formed on the other side thereof. By making the film thickness of the second dielectric layer thinner than that of the first dielectric layer, the metallic reflecting layer is thereby placed closer to the active recording layer, and is able to more rapidly dissipate the heat generated in the active layer by the laser light. This permits a rapid cool down to occur and a highly uniform amorphous mark to be produced. The high uniformity of the amorphous mark is desirable for optimizing the erase characteristics of the material.
The above mentioned composition of the recording layer and overall structure of the optical recording medium therefore inhibits the melt shifting which is known to occur in recording layers having other compositions, and results in a structure in which the long term cyclability and stability of the record/erase characteristics and power dependency of the laser light is improved over the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding the nature, features and advantages of the present invention, reference should be made to the following detailed description of various preferred, but nonetheless illustrative embodiments of the invention, as illustrated by and taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a cross sectional view which shows the structure of an optical information recording medium in accordance with the first and second embodiments of the invention.
FIG. 2 is a cross sectional view which shows the structure of an optical information recording medium in accordance with a third embodiment of the present invention.
FIG. 3 is a cross sectional view which shows the structure of an optical information recording medium in accordance with yet another embodiment of the present invention.
FIG. 4 is a triangular composition diagram showing the preferred composition of the active layer of one embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, there is shown a cross sectional view of an optical recording medium which includes a disc substrate 1 which may be a resin substrate formed from poly-carbonate or other similar material. The disc substrate 1 may have grooves preformed therein for guiding the laser light, which is shown as incident on the disc in the direction of the arrow denoted by reference numeral 8. Alternatively disc substrate 1 may be a glass plate formed by the 2P process, a substrate prepared by directly forming grooves on a glass plate, or a substrate on which bit rows for guiding laser light have been preformed thereon.
As shown in FIG. 1, a first dielectric layer 2 of approximately 160 nm in thickness, which may consist of a mixed film of ZnS and SiO 2 , is formed on top of disc substrate 1. The first dielectric layer 2 has deposited thereon an active layer 3 having a thickness of approximately 20-30 nm, in which nitrogen is incorporated into a composition of Te-Ge-Sb. A second dielectric layer 4 covers the active, recording layer 3. The second dielectric layer 4 may be of the same composition as the first dielectric layer 2, but has a thickness of only approximately 20 nm. Covering the top of the second dielectric layer 4 is a reflecting layer 5 which may be an Al alloy. Finally, to complete the structure, a protective plate 7 is adhered to the top of the reflective layer 5 by means of an adhesive layer 6. Protective plate 7 may be another disc, and in such case top and bottom surfaces of the optical recording medium are discs.
In the structure shown in FIG. 1, the laser light for recording, erasing, and reproducing the information contained therein is incident in the direction shown by arrow 8, and has an intensity which is modulated with the information. Detection of the recorded information may be performed by detecting the reflected light.
To produce the two dielectric layers 2,4, the active layer 3, and reflecting layer 5, a vacuum deposition or embodiment of the active layer 3, for example, a sputtering process may be used in which sputtering is performed in a mixture of a rare gas such as argon and nitrogen gas. During such sputter deposition, the partial pressure of nitrogen in the gas is an important process parameter which determines the characteristics and quality of the active layer 3. During sputtering of the active layer 3, an appropriate range for the partial pressure of nitrogen is 1.0×10 315 Torr to 1.0×10 -4 Torr. If the nitrogen partial pressure is less than approximately 10 -5 Torr, then the effect of nitrogen during sputtering becomes small, and consequently the improvement of the cyclability characteristics as a result of the inclusion of nitrogen in the Te-Ge-Sb active layer structure becomes small. On the other hand, if the partial pressure of nitrogen during sputtering is greater than about 10 -4 Torr, the optical characteristics of the active layer 3, such as the refractive index are affected, and the basic recording and erasing characteristics of the active layer 3, such as the speed of crystallization and non-crystallization move away from their optimum range. Accordingly, the above-mentioned range for the partial pressure of nitrogen during sputter deposition is most appropriate.
With respect to the first dielectric layer 2 and the second dielectric layer 4, the mixing ratio of ZnS and SiO 2 is generally selected so that the SiO, comprises 20 mol % of the overall composition. The composition need not, however, be so limited. However, if the SiO 2 , is less than about 5 mol %, the effect of SiO 2 , on the mixture, i.e. to reduce the diameter of the crystal particles, is diminished. On the other hand, if the concentration of SiO 2 , is above 50 mol %, then the properties of the film degrade. Therefore, it is appropriate to keep the ratio of SiO 2 in the range of 5 to 40 mol %.
The thickness of the second dielectric layer 4 is made as thin as about 20 nm, so that the reflecting layer 5, which also acts as a thermal dissipation layer, is placed closer to the active layer 3. Thus the heat from the active layer 3 generated by the laser beam during recording and erasing may be rapidly conducted to the reflecting layer 5, producing a rapid cooling of the active layer 3 which results in a more uniform amorphous record mark.
Experiments have been performed on the disc structure of the first preferred embodiment of the invention as described above, in which the over-write characteristics of a signal of frequency f1 =3.43 MHz and a signal of frequency f2 =1.25 MHz were measured at an outer diameter of 130 mm, on a disc rotating at 1800 rpm, which corresponds to a linear speed of 8 m/sec. The over-write was carried out by a method of simultaneously recording and erasing, in which a substantially non-crystalline record mark was formed by irradiation at a high laser power level of 16 mw, and then crystallized by irradiation at a low laser power level of 8 mw, with a circular laser spot of about 1 micron in diameter.
As a result of these measurements, a C/N ratio for the recorded signal of 55 db or greater was obtained, with an erasability of greater than 30 db. With respect to repetitive cycling, the bit error rates were measured, with no deterioration observed for over one million cycles.
As a second preferred embodiment, a recording layer is made of a chalcogen which contains a nitride/nitrides of at least one element selected from Te, Ge, and Sb. The optical recording medium consists of a substrate, and a 4-layer structure having a first dielectric layer, an active layer, a second dielectric layer, and a reflecting layer, configured as generally shown in FIG. 1. In this second embodiment, the active layer 3 contains a nitride/nitrides or an oxide/oxides of at least one element selected from Ge, Te, and Sb, and has a film thickness of about 20-30 nm.
To form the structure of the second preferred embodiment, a sputter deposition process or an electron beam evaporation process may be used. For sputter deposition, it is possible to fabricate a sputter target which contains a nitride/nitrides of Ge, Te, or Sb. With such target, it is possible to carry out the sputter deposition with only argon (Ar) gas. It is also Possible to allow the above-mentioned nitride/nitrides to be contained in a deposition source for use in electron beam evaporation.
The disc structure of this second preferred embodiment was studied by investigating the over-write characteristics using a signal of frequency fl =3.43 MHz and a signal of frequency f2 =1.25 MHz applied at an outer diameter of 130 mm to a disc rotating at 1800 rpm, which corresponds to a linear speed of 8 m/sec. The over-write was carried out by a method of simultaneously recording and erasing, in which a substantially non-crystalline record mark was formed by irradiation at a high laser power level of 16 mw, and then crystallized by irradiation at a low laser power level of 8 mw, with a circular laser spot of about 1 micron in diameter.
As a result of these measurements, a C/N ratio for the recorded signal of 55 db or greater was obtained, with an erasability of greater than 30 db. With respect to repetitive cycling, the measurement of bit error rates showed no deterioration after more than one million cycles.
A third embodiment of the instant invention is now explained with reference to FIG. 2, wherein a disc substrate 9 is shown which may be a resin substrate on which grooves for guiding the laser light are preformed, a glass plate formed by the 2P process, a substrate prepared by directly forming grooves on a glass plate, or a substrate on which bit rows for guiding the laser light are provided thereon. Deposited on disc substrate 9 is a first dielectric layer 10, which may consist of a mixed film of ZnS and SiO 2 . An active layer 11 is then deposited on top of the first dielectric layer 10. The active layer 11 is prepared by allowing a component consisting of a Te-Ge-Sb composition to be dispersed in a matrix of a nitride/nitrides or an oxide/oxides of at least one element chosen from Te, Ge and Sb. The film thickness of active layer 11 is in the range of approximately 20-120 nm. Covering the active layer 11 is a second dielectric layer 12, made from the same material as the first dielectric layer 10, which is deposited to a thickness of about 20 nm. A reflecting layer 13 of Al alloy covers the thin second dielectric layer 12. A protective plate 15 is adhered to the top of the structure by an adhesive layer 14.
In this third embodiment, the light absorption coefficient and film thickness of the active layer 11 are chosen in such a manner that in comparison with the first and second embodiments described above, the light absorption coefficient is small, and the film thickness of the recording layer 11 is thicker. When subjected to similar test conditions as described with respect to the first and second embodiments, the C/N ratio of the recorded signal was found to be 55 db or greater, with an erasability of 30 db or greater. As to the effects of repeated write/erase cycling of the medium, the bit error rates were measured, and no deterioration was observed for more than one million cycles.
A fourth embodiment of the invention is shown in FIG. 3. As shown therein, the optical recording medium may contain a disc substrate 16, which may be a resin substrate formed from poly-carbonate or other similar materials. Disc substrate 16 may have grooves preformed therein for guiding the laser light, shown as being incident in the direction of the arrow denoted by reference numeral 25. Alternatively, disc substrate 16 may be a glass plate formed by the 2P process, a substrate prepared by directly forming grooves on a glass plate, or a substrate on which bit rows for guiding laser light have been preformed thereon.
A first dielectric layer 17, which consists of a mixed film of Zn and SiO 2 having a film thickness of approximately 160 nm is deposited on top of the disc substrate 16. The next layer is an active layer 18, which has a Te-Ge-Sb ternary alloy composition as a component thereof, and a nitride/nitrides of at least one of the elements Ge,Te, or Sb, or an adsorption surface layer 20 of nitrogen provided on at least one surface of the active layer 18. A second dielectric layer 21, made from the same material as the first dielectric layer 17, and having a thickness of 20 nm covers the active layer 18. A reflecting layer 22 of Al alloy, having a thickness of about 120 nm covers the second dielectric layer 21. To complete the structure, a protective plate 24 is adhered to the reflecting layer 22 by an adhesive material layer 23.
Experimental measurements performed on this structure, using the parameters described above with respect to the aforementioned embodiments, resulted in a C/N ratio for the recorded signal of 55 db or greater, and an erasability of 30 db or greater. Further, no deterioration was found in the write/erase characteristics after more than one million write/erase cycles.
In a preferred embodiment of this invention, an active recording layer is made from a material which incorporates nitrogen in a Ge, Te and Sb composition. It is especially effective to incorporate nitrogen in a composition range shown in the triangle diagram of FIG. 4, which represents the compositions of the ternary alloy system GeTe-Sb 2 Te 3 -Sb. With such a composition, it is possible to obtain stable characteristics above one million cycles by appropriately selecting the laser power for recording and erasing. Furthermore, in addition to obtaining improved stability characteristics beyond one million write/erase cycles over a wide range of laser power, it is also possible to improve the recording sensitivity of the active layer by permitting the layer to contain nitrogen or by allowing it to contain a nitride/nitrides of at least one element of Ge, Te and Sb. If b=Sb/Sb 2 Te 3 (denoting the mole ratio of these two constituents), then an especially effective composition range for the active recording layer is 0<b<1.0. If b is too small, then the effect of the Te component may become excessive, and render the active layer poor with respect to oxidation resistance. On the other hand, if b>1.0, then the speed of erasure is reduced. Furthermore, if g=GeTe/Sb 2 Te 3 (mole ratio), then the composition range of 0.5 < g<3.0 is preferable. If g is 0.5 or less, the thermal resistance stability is reduced, whereas if g is 3.0 or greater, the sensitivity of the recording layer is reduced, even though the thermal stability remains good.
For the preparation of these layers, a vacuum deposition process or a sputter process may generally be utilized. When sputtering is used to prepare this embodiment of the invention, the sputtering may be performed in a mixture of a rare gas such as argon and nitrogen gas. As explained above, during sputter deposition, the partial pressure of nitrogen in the gas is an important process parameter which determines the characteristics and quality of the active layer. During sputtering of the active layer, an appropriate range for the partial pressure of nitrogen is 1.0×10 -5 Torr to 1.0×10 -4 Torr. If the nitrogen partial pressure is less than approximately 10 -5 Torr, then the effect of nitrogen during sputtering becomes small, and consequently the improvement of the repeatability characteristics as a result of the inclusion of nitrogen in the Te-Ge-Sb active layer structure becomes small. On the other hand, if the partial pressure of nitrogen during sputtering is greater than about 10 -4 Torr, the optical characteristics of the active layer, such as the refractive index is affected, and the basic recording and erasing characteristics of the active layer 18, such as the rate of crystallization and non-crystallization, may be adversely affected. Accordingly, the above-mentioned range for the partial pressure of nitrogen during sputter deposition is optimum.
Experiments have been performed on the disc structure of this preferred embodiment of the invention, in which the over-write characteristics of a signal of frequency fl =3.43 MHz and a signal of frequency f2 =1.25 MHz were measured at an outer diameter of 130 mm, on a disc rotating at 1800 rpm, which corresponds to a linear speed of 8 m/sec. The over-write was carried out by a method of simultaneously recording and erasing, in which a substantially amorphous record mark was formed by irradiation at a high laser power level of 16 mw, and then crystallized by irradiation at a low laser power level of 8 mw, with a circular laser spot of about 1 micron in diameter.
As a result of these measurements, a C/N ratio for the recorded signal of 55 db or greater was obtained, with an over-write erasability of 30 db or greater. With respect to repetitive cycling, the characteristics of bit error rates were measured, with no deterioration observed for over one million cycles.
Although the invention disclosed herein as been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the different aspects and features of the invention. As such, persons skilled in the art may make numerous modifications to the illustrative embodiments described herein, and other arrangement may be devised to implement the disclosed invention which will fall within the spirit and scope of the invention described and claimed herein.
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An optical information recording medium is provided in which the active layer is a phase change material capable of absorbing energy and being converted between a substantially amorphous state and a substantially crystalline state. The active layer contains nitrogen, which may be in the form of a nitride or nitrides of the constituent elements of the active layer, or may be a nitrided surface thereof. The inclusion of nitrogen inhibits localized shifting of the active material, which leads to degradation of the recording/erase properties of the medium. The optical recording medium includes a substrate, onto which is deposited in sequence a first dielectric layer, a nitrogen-containing active layer, a second dielectric layer, and a metallic reflecting layer. The second dielectric layer is made thin, so that the cooling rate of the active layer is increased to form a more uniform amorphous state.
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BACKGROUND
1. Field of the Invention
The present invention relates generally to subsurface equipment for fluid production wells and more particularly to managing fluid flow in annular flow channels.
2. Description of the Related Art
Wellbores are often provided with separate multiple flow channels for moving fluids into and out of subsurface reservoirs. For example, a single injection well may be required to provide injection fluids to two or more layers in a reservoir in which case two separate flow channels are required. As another example, a single wellbore may be used to provide both a means for producing fluid from a reservoir and also provide a supply and return conduit for supplying a working fluid to a subsurface device.
One way of separating the flow channels is to use separate tubing strings in parallel and placed into a single wellbore. This method is useful for shallow wells having low flow rates but is impractical for wells having higher flow rates or deep wells where pressure drops caused by the required narrow tubing strings are unacceptable. Instead, concentric tubing strings are used wherein one or more tubing strings are nested one inside another creating multiple annular flow channels defined by the inner wall of a first tubing string and the outer wall of a second tubing string passing through the annulus of the first tubing string. As the annular flow channels are separated by the tubing walls, the annular flow channels are isolated from one another in regard to pressure and the exchange of fluids. In addition, insulated tubing strings may also provide some thermal isolation between the annular flow channels.
One problem associated with concentric tubing strings is that the assignment of the fluids in each annular fluid channel is typically fixed. That is, once a fluid enters one of the annular flow channels, it must remain in that annular fluid channel and cannot be switched with fluid from another annular fluid channel. This may cause a problem, for example, when a subsurface device, such as turbine driven pump, needs to be placed in the wellbore and fluid needs to routed to the device around another intervening device in the tubing string.
Therefore, a need exists for a way to switch fluids between annular flow channels within a wellbore. Various aspects of the present invention meet such a need.
SUMMARY OF THE INVENTION
A concentric tubing well completion system and subsurface annular flow crossover are provided. The well completion system creates at least three concentric annular flow channels in a wellbore. One or more subsurface flow crossovers provide for switching fluid flow between the annular flow channels within the completed well. A crossover can be used in conjunction with other subsurface equipment to more efficiently manage fluid flows in the completed well for the purposes of produced fluid extraction and supply of a working fluid to a subsurface device.
In one aspect of the invention, three or more concentric tubing strings create a concentric tubing string with independent annular flow channels from an underground fluid reservoir to ground level or above ground level. A separate device or flow loop is installed at the lower end of the concentric tubing string to create a pressure isolated, continuous, flow loop from the surface end to the underground end of the concentric tubing string. The system uses a flow crossover that allows the fluid in any annulus to be redirected into any of the other annuli while maintaining the pressure and chemical integrity of the fluid.
In another aspect of the invention, the flow crossover can be mounted at any point in the tubing string. In addition, multiple flow crossovers can be installed downhole to allow movement of the fluid from one annulus to another as desired.
In another aspect of the invention, the system uses threaded joints with sliding seals at the lower end of the interior tubing strings to allow installation and extraction of the underground equipment with surface lifting equipment alone. No subsurface grappling or latching equipment is required.
In another aspect of the invention, the system can be assembled into different sections in which the fluid flowing in one annulus may be switched to flow into a different annulus. This can allow changing the flow path of hot and cold fluid streams. The system can be used to recover heat from a fluid stream, control solids precipitation by maintaining fluid temperature, use a heated circulating fluid to lower the fluid viscosity of a produced fluid.
This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description in connection with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood from a detailed description of the exemplary embodiments taken in conjunction with the following figures:
FIG. 1 is a schematic diagram of a well completion system for a wellbore in accordance with an exemplary embodiment of the invention.
FIG. 2 a is a cross-sectional drawing of an upper annular flow crossover and an upper portion of a subsurface heat exchanger in accordance with an exemplary embodiment of the invention.
FIG. 2 b is a cross-sectional drawing of a heat exchanger section in accordance with an exemplary embodiment of the invention.
FIG. 2 c is a cross-sectional drawings of two heat exchanger sections joined together in accordance with an exemplary embodiment of the invention.
FIG. 3 is a cross-sectional drawing of a lower annular flow crossover and a lower portion of a subsurface heat exchanger in accordance with an exemplary embodiment of the invention.
FIG. 4 is a cross-sectional drawing of a subsurface fluidically driven pump in accordance with an exemplary embodiment of the invention.
FIGS. 5 a to 5 i are schematic drawings of an assembly sequence for a well completion system in accordance with an exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic diagram of a well completion system in accordance with an exemplary embodiment of the invention. The well completion system 100 includes two subsurface sections, a heat exchanger section 101 and a fluidically powered pumping section 102 , that extend into a well bore 103 . As depicted in the diagram, the wellbore is intended for production of geothermally heated brine from a subsurface production zone 104 ; however, it is to be understood that the well completion system is not limited to only geothermal applications.
The well completion system 100 uses concentric tubing strings having three concentric pipes or tubing strings to create independent flow paths from the production zone 104 to the surface. A separate device or flow loop can be installed at the lower end of the concentric tubing strings to create a pressure isolated, continuous, flow loop from the surface to the underground end of the concentric tubing strings. The well completion system 100 uses annular flow crossovers that allow a fluid in any annular flow channel of the concentric tubing strings to be redirected into any other annular flow channel while maintaining the pressure and chemical integrity of the fluid. The annular flow crossovers can be mounted at any point in the concentric tubing strings. Multiple annular flow crossovers can be installed downhole to allow movement of the fluid from one annular flow channel to another as desired.
The well completion system 100 uses threaded joints with sliding seals at the lower end of the interior tubing strings of the concentric tubing strings to allow installation and extraction of the underground equipment with surface lifting equipment alone. No subsurface grappling or latching equipment is required. The well completion system 100 can be assembled into different sections in which the fluid flowing in one annular flow channel may be switched to flow into a different annular flow channel. This can allow changing the flow path of hot and cold fluid streams. The well completion system 100 can be used to recover heat from a fluid stream, control solids precipitation by maintaining fluid temperature, use a heated circulating fluid to lower the fluid viscosity of a produced fluid, etc.
The entire underground assembly consists of sections of concentric tubing strings. A annular flow crossover is installed at the top and bottom of each intermediate section to redirect the fluid flowing in one annular flow channel into a different annular flow channel, if desired. Each separate section is run by assembling joints of the outside tubing string with threaded connections at each end. The bottom section of the outside tubing string of a concentric tubing string supports any type of downhole device installed at the lower end of the tubing string. The device incorporates polished receptacles at the top of the device. These receptacles are capable of accepting a seal assembly installed at the lower end of each interior tubing string. The interior tubing string strings are installed after the outside tubing string is assembled and suspended in the hole. The concentric tubing string strings are installed sequentially from the outer string toward the center string. The lower end of each interior tubing string with the seal installed at the end are assembled and additional sections added until the seal enters the receptacle at the bottom of the adjacent outer string.
The tubing string being run is suspended by a hanger assembly mounted on the inside of the outer tubing string. The top of each tubing string has a seal receptacle installed. This allows the installation of the annular flow crossover assembly with its seals to isolate each flow path. Subsequent sections can vary in design. Some possible design configurations include single or multiple heat exchanger sections, intermediate concentric tubing string sections, flow limiting sections, and pumping devices. These sections can be interspersed and placed at any intermediate depth in the well.
The well completion system 100 includes a heat exchanger section 101 connected to an upper concentric tubing string section 105 that has a plurality of annular flow channels. The upper concentric tubing string section 105 is mechanically connected at a lower end to an upper annular flow crossover 106 . The upper annular flow crossover provides both mechanical and fluidic connectivity between the annular flow channels of the upper concentric tubing string section 105 and a heat exchanger 107 . The heat exchanger is connected at a lower end to a lower annular flow crossover 108 . The lower annular flow crossover 108 mechanically and fluidically connects the heat exchanger 107 to a lower concentric tubing string section 110 that is connected to fluidically powered pumping section 102 . The lower concentric tubing string section 110 provides mechanical and fluidic connectivity between the lower flow crossover 108 and a fluidically driven pump 112 . The fluidically driven pump 112 is optionally mechanically and fluidically connected to a tail pipe 114 that extends into the production zone 104 .
The well completion system 100 and the concentric tubing strings can accommodate a working fluid that both drives the fluidically driven pump 112 and extracts heat from heated brine produced from the production zone 104 . To do so, downwardly flowing working fluid flows through a respective annular flow channel of the concentric tubing strings 105 and 110 . Returning upwardly flowing working fluid flows to the surface through another respective annular flow channel of the concentric tubing strings 105 and 110 . In addition, heated brine produced from the production zone 104 flows through yet another annular flow channel of the concentric tubing strings 105 and 110 .
In operation, the downwardly flowing working fluid is pumped into the upper concentric tubing string section 105 down through the upper annular flow crossover 106 which routes the downwardly flowing working fluid into the heat exchanger 107 . The downwardly flowing working fluid then flows out of the heat exchanger 107 and into the lower annular flow crossover 108 which routes the downwardly flowing working fluid to the fluidically driven pump 112 . The fluidically driven pump 112 is driven by the downwardly flowing working fluid which draws heated brine from the production zone 104 . The heated brine is pumped toward the surface along with the returning upwardly flowing working fluid. The heated brine and upwardly flowing working fluid travel up through the lower concentric tubing string section 110 in their separate respective concentric flow channels to the lower annular flow crossover 108 . The lower annular flow crossover routes the heated brine into the heat exchanger and the upwardly flowing working fluid through the heat exchanger 107 . In the heat exchanger, heat is extracted from the heated brine into the working fluid.
After leaving the heat exchanger, the heated brine and upwardly flowing working fluid are produced from the well at the surface. Once at the surface, the heated working fluid is used to power a turbine that in turn drives an electrical generator. The working fluid is then circulated back into the well completion system 100 . Residual heat in the brine may also be extracted and used to power a turbine before the brine is injected back into the production zone.
As described herein, the well completion system 100 maintains a separated flow channel from the production zone to the surface for brine produced from the production zone. It is to be understood that the well completion system can be used to move brine between different production and injection zones, from more than one production zone, into more than one injection zone etc. as the well completion system 100 can accommodate additional intermediate openings into the tubing strings or well casing.
In other embodiments of the well completion system 100 , the tail pipe 114 is dispensed with and an alternative completion method is used at the bottom of the wellbore. The alternative completion method can include an open hole completion, another concentric tubing string, etc.
Having provided an overview of the well completion system in accordance with an exemplary embodiment of the invention, individual components of the well completion system will now be described in greater detail with reference to FIGS. 2 a , 2 b , 2 c , 3 and 4 where like numbered elements refer to the same features illustrated in the figures. FIG. 2 a is a cross-sectional drawing of an upper annular flow crossover in accordance with an exemplary embodiment of the invention. The upper annular flow crossover 106 mechanically and fluidically connects the upper concentric tubing string section 105 to the subsurface heat exchanger 107 . The concentric tubing string 105 has an outermost tubing string 200 and one or more concentric successive tubing strings, such as tubing strings 202 and 204 . Each successive tubing string defines an annular flow channel between an inner surface of a preceding tubing string and an outer surface of the successive tubing string. For example, tubing strings 200 and 202 define one annular flow channel 206 therebetween and tubing strings 202 and 204 define another annular flow channel 208 therebetween. In addition, an innermost annular flow channel 210 is defined by an interior surface of the innermost tubing string 204 . Therefore, a number of successive annular flow channels are defined that succeed from an outermost tubing string flow channel 206 to an innermost tubing string flow channel 210 .
The upper annular flow crossover 106 has one or more flow channels, such as flow channels 212 and 214 , fluidically connecting a tubing string flow channel of the upper concentric tubing string section 105 to a non-corresponding flow channel in the heat exchanger 107 . For example, flow channel 214 connects annular flow channel 208 to a relatively outer non-corresponding flow channel 216 of the heat exchanger 107 . In addition, flow channel 212 connects annular flow channel 206 to a relatively inner non-corresponding flow channel 218 of heat exchanger 107 .
In addition, the annular flow crossover 106 may have one or more flow channels that fluidically couple a corresponding flow channel of the upper tubing string 105 to the heat exchanger 107 . For example, flow channel 210 of the concentric tubing string 105 is connected to central flow channel 222 of the heat exchanger 107 via flow channel 220 of the upper annular flow crossover 106 .
In one embodiment of an annular flow crossover in accordance with the invention, the annular flow crossover 106 is threadably connected to the outermost tubing string 200 and to an outer tube 223 of the heat exchanger 107 . In addition, the annular flow crossover 106 is slidably and rotably coupled to the successive tubing strings, such as tubing strings 202 and 204 , of the upper concentric tubing string section 105 and an inner tube 224 of the heat exchanger 107 .
The heat exchanger 107 is constructed of an inner tube 224 within an outer tube 223 . The annular flow channel 232 between the inner tube 224 and the outer tube 223 has one or more heat exchange tubes, such as heat exchange tubes 244 , 246 and 248 , passing therethrough. The heat exchange tubes define one or more isolated internal flow channels, such as internal flow channels 245 , 247 and 249 , through the heat exchanger. The heat exchange tubes are installed and sealed at an upper plate 250 and a lower plate (not shown) located at a respective each end of the inner tube 224 and the outer tube 223 , thus creating a shell and tube exchanger. A fluid stream flowing through the heat exchange tubes is isolated from a fluid flowing in the annular flow channel 232 . A shell side of the heat exchanger 107 is thus defined as the flow channel 232 between the inner tube 224 and the outer tube 223 and external to the heat exchange tubes.
Fluid that flows through the shell side of the heat exchanger 107 flows into one or more ports, such as port 252 , cut in a side of the outer tube 223 and through the annular flow channel 216 between an outside surface of the outer tube 223 and a concentric threaded collar 254 that threadably connects the upper annular flow crossover 106 to the heat exchanger 107 via a sealing collar 255 on an exterior surface of the outer tube 223 . The concentric threaded collar 254 provides both a structural connection and a pressure tight seal between the upper annular flow crossover 106 and the heat exchanger 107 .
In operation, the upper annular flow crossover 106 receives downwardly flowing working fluid (as indicated by flow arrows 225 , 226 , 228 and 230 ) from annular flow channel 208 and routes the downwardly flowing working fluid to flow channel 216 of the heat exchanger 107 via flow channel 214 . The downwardly flowing working fluid then flows into flow chamber 232 of heat exchanger 107 .
In addition, the upper annular flow crossover 106 receives upwardly flowing heated brine (as indicated by flow arrows 234 , 236 and 238 ) from the heat exchanger 107 and routes the upwardly flowing heated brine from flow channel 218 of the heat exchanger to flow channel 206 of the upper concentric tubing string section 105 . While in the heat exchanger 107 , heat is transferred from the heated brine to the downwardly flowing working fluid.
The upper annular flow crossover 106 also receives upwardly flowing heated working fluid (as indicated by flow arrows 240 and 242 ) from the heat exchanger 107 . The upper annular flow crossover 106 routes the upwardly flowing heated working fluid into the innermost flow channel 210 of the concentric tubing string 105 from flow channel 222 of the heat exchanger 107 by flow channel 220 of the upper annular flow crossover 106 .
FIG. 2 b is a cross-sectional diagram of a heat exchanger in accordance with an exemplary embodiment of the invention. As previously described, the heat exchanger 107 is constructed of an inner tube 224 within an outer tube 223 . An inner surface of the inner tube 224 defines a central flow channel 222 . An annular flow channel 232 is defined between an outer surface of the inner tube 224 and the inner surface of outer tube 223 . The annular flow channel 232 has one or more heat exchange tubes, such as heat exchange tubes 244 , 246 and 248 , passing therethrough. The heat exchange tubes define one or more isolated internal flow channels, such as internal flow channels 245 , 247 and 249 , through the heat exchanger 107 . The heat exchange tubes are installed and sealed at an upper plate 250 and a lower plate 350 located at a respective each end of the inner tube 224 and the outer tube 223 , thus creating a shell and tube exchanger. Fluid that flows through the annular flow channel 232 of the heat exchanger 107 flows through one or more ports, such as ports 252 and 352 , cut in a side of the outer tube 223 .
The outer tube 223 has a sealing assembly 254 and a receptacle 256 for receiving a sealing assembly located at respective ends of the outer tube 223 . The inner tube 224 is similarly constructed as inner tube 224 also has a sealing assembly 258 and a receptacle 260 for receiving a sealing assembly located at respective ends.
Respective upper and lower sealing collars 255 and 355 are located on an exterior surface of the outer tube 223 . The sealing collars 255 and 355 are used to threadably connect the heat exchanger 107 to a tubing string or an annular flow crossover using a concentric threaded collar as previously described. The sealing collars may be separate components that are connected to the exterior surface of the outer tube 223 or may be part of a machined assembly that incorporates the other features of an end portion of outer tube 223 , such as sealing assembly 254 , receptacle 256 , port 352 , port 252 , etc. as may be desired.
FIG. 2 c is a cross-sectional drawings of two heat exchangers joined together in accordance with an exemplary embodiment of the invention. In one embodiment of a subsurface heat exchanger in accordance with the invention, any number of heat exchangers, such as heat exchangers 270 and 272 , can be assembled sequentially in a wellbore in the same way as normal oil field casing or tubing. The flow paths for the fluid flowing through heat exchanger tubes, such as heat exchanger tube 273 , and a central flow channel 274 are isolated using a stab-in type of seal assembly and receptacle, such as seal assembly 280 and receptacle 278 for the central flow channel, and seal assembly 273 and receptacle 276 for the flow flowing through the heat exchanger tubes. Such a seal mechanism provides a seal to prevent any fluid cross flow between the other flow paths.
The heat exchanger sections 270 and 272 are joined together by a threaded concentric collar 275 that mates with a first sealing collar 292 and a second sealing collar 294 . The threaded concentric collar forms a flow channel 296 around the mated outer sealing assembly 273 and respective receptacle 276 . The flow channel 296 provides a flow channel for fluid flowing through as shell side of the heat exchanger, as indicated by flow arrows 288 and 290 .
The heat exchanger sections 270 and 272 can be supplied with or without a concentric coupling collar 275 already assembled to one end of a heat exchanger section. Assembly of the concentric coupling collar 275 and heat exchanger sections 270 and 272 can thus be accomplished at a well site using standard oil field equipment.
As depicted in FIGS. 2 a , 2 b and 2 c , the sealing assemblies and corresponding receptacles are configured such that entry of each sealing assembly into its corresponding receptacle may be confirmed prior to contact of the coupling. In other embodiments of heat exchanger sections, a sealing assembly and its corresponding receptacle may be connected after the threading of a sealing collar with a threaded concentric collar has begun.
FIG. 3 is a cross-sectional drawing of a lower annular flow crossover in accordance with an exemplary embodiment of the invention. The lower annular flow crossover 108 mechanically and fluidically connects the lower concentric tubing string section 110 to the subsurface heat exchanger 107 . The lower concentric tubing string section 110 has an outermost tubing string 300 and one or more concentric successive tubing strings, such as tubing strings 302 and 304 . Each successive tubing string defines an annular flow channel between an inner surface of a preceding tubing string and an outer surface of the successive tubing string. For example, tubing strings 300 and 302 define one annular flow channel 306 therebetween and tubing strings 302 and 304 define another annular flow channel 308 therebetween. In addition, an innermost annular flow channel 310 is defined by an interior surface of the innermost tubing string 304 . Therefore, a number of successive annular flow channels are defined that succeed from an outermost tubing string flow channel 306 to an innermost tubing string flow channel 310 .
The lower annular flow crossover 108 has one or more flow channels, such as flow channels 312 and 314 , fluidically connecting a tubing string flow channel of the lower concentric tubing string section 110 to a non-corresponding flow channel in the heat exchanger 107 . For example, flow channel 312 connects annular flow channel 306 to a relatively inner non-corresponding flow channel 318 of the heat exchanger 107 . In addition, flow channel 314 connects annular flow channel 308 to a relatively outer non-corresponding flow channel 316 of heat exchanger 107 .
In addition, the lower annular flow crossover 108 may have one or more flow channels that fluidically couple a corresponding flow channel of the lower tubing string 110 to the heat exchanger 107 . For example, flow channel 310 of the lower concentric tubing string section 110 is connected to central flow channel 222 of the heat exchanger 107 via flow channel 320 of the lower annular flow crossover 108 .
In one embodiment of a lower annular flow crossover in accordance with the invention, the lower annular flow crossover 108 is threadably connected to the outermost tubing string 300 and to an outer tube 223 of the heat exchanger 107 . In addition, the annular flow crossover 108 is slidably and rotably coupled to the successive tubing strings, such as tubing strings 302 and 304 , of the lower concentric tubing string section 110 and an inner tube 224 of the heat exchanger 107 .
As previously described, the heat exchanger 107 consists of an inner tube 224 within an outer tube 223 . The annular flow channel 232 between the inner tube 224 and the outer tube 223 has one or more heat exchange tubes, such as heat exchange tubes 244 , 246 and 248 , passing therethrough. The heat exchange tubes are installed and sealed at an upper plate (not shown) and a lower plate 350 located at a respective each end of the inner tube 224 and the outer tube 223 , thus creating a shell and tube exchanger. A fluid stream flowing through the heat exchange tubes is isolated from a fluid flowing in the annular flow channel 232 . A shell side of the heat exchanger 107 is thus defined as the flow channel 232 between the inner tube 224 and the outer tube 223 and external to the heat exchange tubes.
Fluid that flows through the shell side of the heat exchanger 107 flows through one or more ports, such as port 352 , cut in a side of the outer tube 223 and through the annular flow channel 316 between an outside surface of the outer tube 223 and a concentric threaded collar 354 that threadably connects the lower annular flow crossover 108 to the heat exchanger 107 via a sealing collar 355 on an exterior surface of the outer tube 223 . The concentric threaded collar 354 provides both a structural connection and a pressure tight seal between the lower annular flow crossover 108 and the heat exchanger 107 .
In operation, the lower annular flow crossover 108 receives upwardly flowing heated brine (as indicated by flow arrows 334 , 336 and 338 ) from flow channel 306 of the lower concentric tubing string section 110 and routes the heated brine via flow channel 312 into flow channel 318 of the heat exchanger 107 . While in the heat exchanger, heat is transferred from the heated brine to the downwardly flowing working fluid.
In addition, the lower annular flow crossover 108 receives downwardly flowing working fluid (as indicated by flow arrows 325 , 326 , 328 and 330 ) from flow channel 316 of heat exchanger 107 and routes the downwardly flowing working fluid to flow channel 308 of the lower concentric tubing string section 110 via flow channel 314 .
The lower annular flow crossover 108 also receives upwardly flowing heated working fluid (as indicated by flow arrows 340 and 342 ) from the lower concentric tubing string section 110 . The lower annular flow crossover 108 routes the upwardly flowing heated working fluid from the innermost flow channel 310 of the lower concentric tubing string section 110 to flow channel 222 of the heat exchanger 107 by flow channel 320 of the lower annular flow crossover 106 .
FIG. 4 is a cross-sectional drawing of a subsurface fluidically driven pump in accordance with an exemplary embodiment of the invention. The fluidically driven pump 112 is mechanically and fluidically connected to the lower concentric tubing string section 110 . As previously described, the lower concentric tubing string section 110 has an outermost tubing string 300 and one or more concentric successive tubing strings, such as tubing strings 302 and 304 . Each successive tubing string defines an annular flow channel between an inner surface of a preceding tubing string and an outer surface of the successive tubing string. For example, tubing strings 300 and 302 define one annular flow channel 306 therebetween and tubing strings 302 and 304 define another annular flow channel 308 therebetween. In addition, an innermost annular flow channel 310 is defined by an interior surface of the innermost tubing string 304 . Therefore, a number of successive annular flow channels are defined that succeed from an outermost tubing string flow channel 306 to an innermost tubing string flow channel 310 . A seal assembly, such as seal assembly 410 , is mounted at the lower end each concentric tubing string. Each seal assembly on each concentric tubing string is slipped into a seal receptacle, such as seal receptacle 412 .
The fluidically driven pump 112 is further coupled to an tail pipe 114 that has a lower opening (not shown) in communication with a reservoir of hot brine. In operation, downwardly flowing working fluid (as indicated by flow arrow 400 ) flows into the fluidically driven pump 112 from the annular flow channel 308 of the lower concentric tubing string section 110 . The fluidically driven pump 114 is then driven by the working fluid and takes in heated brine (as indicated by flow arrow 401 ) from tail pipe 114 and pumps the heated brine (as indicated by flow arrow 402 ) upwardly through the annular flow channel 306 of the lower concentric tubing string section 110 . After driving the fluidically driven pump 112 , the working fluid flows (as indicated by flow arrow 404 ) upwardly through flow channel 310 of the lower concentric tubing string section 110 .
In the foregoing description, the outermost annular flow channel in the concentric tubing strings 105 and 110 is depicted as containing heated brine, the next successive annular flow channel is depicting as containing downwardly flowing working fluid and the innermost flow channel is depicted as containing heated working fluid. However, in various other embodiments of the invention, the order and assignment of flow channels can be altered in accordance with the needs of the fluids being conveyed as the order and assignment is arbitrary. Furthermore, the order and assignment of the flow channels may be altered such that the different sections of concentric tubing strings have a different order and assignment. In addition, in the foregoing description only three flow channels are depicted. In other embodiments of the invention, fewer or more flow channels may be provided without deviating from the spirit of the invention.
Having described the individual components of a well completion system in accordance with an exemplary embodiment of the invention, the assembly procedure for such a well completion system will now be described in reference to FIGS. 5 a to 5 i where like numbered elements refer to the same features illustrated in the figures. FIGS. 5 a to 5 i are schematic drawings of an assembly sequence for a well completion system in accordance with an exemplary embodiment of the invention. A fluidically driven downhole pump 500 is a combination fluidically-driven power turbine and pump. The power turbine rotates the pump at sufficient speed to generate a fluid pumping action. The turbine and pump are adjacent to each other and mounted as a common assembly. The power turbine is powered by a working fluid (not shown) descending from the surface as previously described.
A concentric tubing string provides a circulation loop for the working fluid to return to the surface as previously described. To build the concentric tubing string, the fluidically driven pump 500 is installed on a lower end of an outer tubing string 506 and lowered into a well 508 as with conventional oil field casing and tubing. The outer tubing string 506 with the fluidically driven pump 500 connected to the lower end of the outer tubing string 506 is suspended at the drilling rig floor using conventional casing slips. After reaching a selected depth, a false rotary is installed at a drilling rig floor. This allows the weight of subsequent smaller, inside tubing strings 512 and 514 to be transferred to the rig floor during running of the inside tubing strings 512 and 514 . The false rotary supports a smaller set of slips and to support the inside tubing strings 512 and 514 as they are run into the larger outside tubing string 506 .
Modified pipe hangers 522 are installed at the top of the outer tubing string 506 to allow suspension of the inside tubing string 512 in the outer tubing string. This same type of arrangement is used to run and suspend all subsequent tubing strings as the pipe size decreases. For example, tubing string 512 has pipe hangers 523 mounted on inner surface of tubing string 512 from which tubing string 514 is suspended.
A set of seal receptacles are installed at the top of the fluidically driven pump 500 and the inside tubing strings 512 and 514 each have a seal assembly mounted at the lower end of the concentric tubing string as previously described. Each seal assembly on each tubing string is slipped into a respective seal receptacle at the top of the fluidically driven pump 500 . This provides a pressure tight isolation of each of the inside tubing strings 512 and 514 . The seal assemblies allow movement of each seal within the seal's respective receptacle to compensate for pipe movement because of wellbore temperature changes. The inside tubing strings 512 to 514 are run in sequence from the largest to the smallest. Each inside tubing string is run, stabbed into the seal receptacle at the bottom of the tubing string and suspended by a hanger, such as hanger 522 , at the top of the next larger tubing string.
The well completion system allows intermediate equipment to be installed in a tubing string with concentric tubing strings and allows pressure isolation between the concentric tubing strings, if desired. The same system for running, sealing and hanging can be used at multiple depths in the well.
An optional tail pipe 532 is installed below the fluidically driven pump 500 to allow the installation of many different types of devices. Some of the possible devices are screens for filtration of the borehole fluid, slotted pipe to help guide the assembly into the hole and prevent the intrusion of wellbore debris and seal assemblies to isolate fluid flow from lower in the wellbore, mounting of packer assemblies to allow wellbore zonal isolation, centering devices, vibration damping devices, and the like.
Having presented an overview of the well completion system installation process, the order of installation of the well completion system components will now be presented in reference to FIGS. 5 a to 5 i in sequence.
As depicted in FIG. 5 a , the fluidically driven pump 500 is lowered into well 508 . The fluidically driver pump 500 is connected to a lower end of outer tubing string 506 . In FIG. 5 b , inner tubing string 512 is inserted into outer tubing string 506 . The lower end of inner tubing string 512 has a sealing assembly that is inserted into a sealing receptacle of fluidically driven pump 500 . In FIG. 5 c , inner tubing string 514 is inserted into inner tubing string 512 and is sealably connected to fluidically driven pump 500 by a respective sealing assembly and sealing receptacle.
In FIG. 5 d , a lower annular flow crossover 534 as described in FIG. 3 is attached to an upper end of the concentric tubing string created from tubing strings 506 , 512 and 514 . In FIG. 5 e , one or more heat exchanger sections 536 (as described in FIG. 2 and FIG. 3 ) are installed to the lower annular flow crossover 534 . In FIG. 5 f , an upper annular flow crossover 538 (as described in FIG. 2 ) is installed on an upper end of heat exchanger 536 .
As depicted in FIG. 5 g , an outer tubing string 540 of an upper concentric tubing string is installed. In FIG. 5 h , an inner tubing string 542 of the upper concentric tubing string is installed. In FIG. 5 i , another inner tubing string 542 is installed, thus completing the well completion system.
While the invention has been particularly shown and described with respect to exemplary embodiments thereof, it will be understood by those skilled in the art that changes in form and details may be made therein without departing from the scope and spirit of the invention.
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An apparatus for creating multiple and isolated well flow paths operating at different pressures in the wellbore is described. These multiple flow paths establish a full circulation loop with the surface and a remaining isolated flow channel produces reservoir fluids to the surface. Heat is transferred from the produced reservoir fluid into the circulated loop via a unique down-hole heat exchanger. The flow of reservoir fluid through the isolated annular well channel allows for more efficient and extensive extraction of heat from the reservoir fluid compared with merely heating the circulating loop via the well bore exterior surface.
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BACKGROUND OF THE INVENTION
This application pertains to the art of illumination systems used in connection with automated visual inspection systems and will be described with reference thereto. However, it will be appreciated that the invention has broader applications, such as in the provision of an extremely reliable and uniform lighting system for any application requiring controlled illumination.
Machine vision continues to obtain increasing significance in industry to aid in robotic assembly systems as well as inspection systems for product sorting or quality control. Such machine vision systems are comprised generally of a lighting system to illuminate a specimen and a camera for capturing light reflected therefrom. A digitized image is formed from the light received by the camera.
More recently, implementations of configurable, solid-state lighting arrays and machine vision systems have improved significantly overall performance levels and quality in such systems. See, for example, U.S. Pat. No. 4,882,498 to Cochran et al., commonly owned by the assignee hereof and incorporated herein by reference.
While initial techniques for forming solid-state lighting arrays provided significant improvement over earlier lighting systems, they nonetheless provided some limitations in obtainable total light output intensity, as well as being expensive to fabricate. These concerns are particularly significant in applications employing large lighting arrays, such as required for inspecting materials provided in a continuous web format, such as textiles, films, paper, metals, and the like.
Configurable solid-state lighting arrays are presently fabricated using individually packaged LED components. In such a construction, an individual light emitting p-n junction chip is typically encapsulated in a transparent epoxy. The epoxy acts to mechanically support the sensitive diode. Additionally, the epoxy capsulation is often molded into a spherical shape, thus giving it some lensing action. The lens-like characteristics of the epoxy encapsulation effectively concentrates the broad angular distribution of light emitted by a diode junction into a limited cone angle.
Such LED construction is often useful in applications in which the device is used as a panel or circuit board indicator. However, in machine vision applications wherein it is desirable to generate a uniform illumination pattern over a broad spatial field, the tendency of a lensed LED to generate illumination "hot spots" is deleterious.
Earlier attempts to address the hot spot problem have employed such means as diffusers disposed between LEDs and a target, or with an increase of a distance between the LED light source and the target.
Yet another draw back inherent to conventionally fabricated solid-state lighting arrays is the relatively large physical space requirement for epoxy packaging. A typical light emitting surface of a p-n junction is approximately 0.010 inches square. This small junction is usually encapsulated in a package with a diameter ranging from 0.10 inches to 0.25 inches. Thus, the ability to pack individual LEDs together into an array is constrained to a large degree by the packaging of the individual LED devices themselves.
Yet another disadvantage of illumination sources employing individually packaged LEDs is provided by virtue of the fact that the epoxy material in which they are encapsulated is a poor heat conductor. An important factor which limits the amount of light which may be emitted from an LED is the surface temperature of the associated emitting p-n junction. As surface temperature increases, the current-to-light-conversion efficiency of the device decreases correspondingly. Additionally, as the drive current of a device is increased, the power dissipated by the LED in the form of heat also increases. This tends to raise the surface temperature of the p-n junction. Thus, conventional LEDs are self-limited in the amount of light which they can generate.
The subject invention overcomes the above problems, and others, providing a dense array of solid-state light emitting diodes capable of providing an extremely high light output.
THE SUMMARY OF THE INVENTION
The present invention contemplates a new and improved machine vision inspection illumination system which overcomes all of the above-referred problems, and others, and provides solid-state illumination less expensively and with higher light output and improved lighting uniformity.
In accordance with the present invention, there is provided a high-density, solid-state lighting array which includes a dense array of semiconductor LEDs that are incorporated onto an electrically insulative, thermally conductive base portion. A heat dissipator is disposed in a thermally conductive path with the base portion so as to quickly communicate heat away from the LEDs.
In accordance with a more limited aspect of the present invention, the heat dissipating mechanism includes a thermal electric module which is suitably provided with a finned heat sink.
In accordance with another aspect of the present invention, the electrically insulative, thermally conductive base portion is comprised of at least one of beryllium oxide, aluminum oxide, and an insulated metal substrate.
In accordance with a yet more limited aspect of the present invention, a lens or window is provided between the lighting array and an associated specimen to direct and/or homogenize light resulting therefrom.
An advantage of the present invention is the provision of a solid-state lighting system which is particularly suited to automated machine vision systems.
Yet another advantage of the present invention is the provision of a solid-state illumination system which generates a high light output from a relatively inexpensive array.
Yet another advantage of the present invention is the provision of a solid-state illumination system which provides extremely uniform light output.
Further advantages will become apparent to one of ordinary skill in the art upon a reading and understanding of the subject specification.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts, and arrangements of parts, a preferred embodiment of which is described in detail in the specifications and illustrated in the accompanying drawings which form a part hereof, and wherein:
FIG. 1 provides a perspective view of a solid-state illumination assembly in accordance with the present invention;
FIG. 2 shows an alternative embodiment of the array of the present invention;
FIG. 3 illustrates generally a Lambertian-type diffuser element;
FIG. 4 illustrates generally a diffractive-type diffuser element;
FIG. 5 shows an alternative embodiment of the present invention;
FIG. 6 shows an alternative embodiment of the present invention; and,
FIG. 7 is a schematic diagram of a video inspection system employing the solid-state illumination array of the subject invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings wherein the figures are for the purpose of illustrating the preferred embodiment of the invention only, and not for the purpose of limiting the same, FIG. 1 illustrates a preferred embodiment of a high-density solid-state lighting array of the subject invention. The array A includes a base portion 10 comprised of an electrically-insulative, thermally-conductive material. Several high thermal conductivity substrates are advantageously used to form the base portion 10. Suitable materials include beryllium oxide (BeO), aluminum oxide (Al 2 O 3 ), as well as insulated metal substrates (IMS) or graphite substrates. BeO and Al 2 O 3 are ceramic compounds which provide good thermal conductivity combined with relatively poor electrical conductivity. Indeed, the substrate is selected for its ability to facilitate the conduction of locally generated thermal energy away from the lighting array while at the same time provide electric isolation to support parallel and series circuitry associated with the lighting array. IMS are composite materials which are comprised of a high thermal conductivity metal structure (such as copper, aluminum, or stainless steel) combined with a thin layer (about 0.003 inches thick) of ceramic film. Such ceramic film provides an electrically insulting layer upon which LED devices are secured, such as will be detailed below.
Typical thermal conductivity values for several of the substrate materials which are suitable for use in connection with the subject invention are presented below.
______________________________________ THERMAL CONDUCTIVITYMATERIAL (W/M · ° K.!______________________________________BeO 220.3Al.sub.2 O.sub.3 29.8Copper 398Aluminum 205H.sub.2 O (reference) .60FR-4 (standard printed .26circuit board)______________________________________
In the illustration of FIG. 1, the generally-planar base portion 10 has several light emitting elements in the form of light emitting diodes (LEDs) 12 disposed on a single surface thereof. The LEDs emit light when electrically forward biased. In the illustration, each of the LEDs 12 is formed of a semiconductor compound and has an associated p-n junction, a representative one of which is illustrated generally at 14. The selected semiconductor compound used to form the LEDs 12 has the property of directly converting a percentage of the electrons which are conducted through their volume into emitted photons in the UV, visible, and/or IR portions of the electromagnetic spectrum. The selected compound could comprise AlGaAs, A1InGaP, GaP, GaAs, and/or GaN. The p-n junction is disposed between a conductor such as 16 and each semi-conductor, a representative of which one of which is provided at 12a. A spacing d, which is approximately 0.05" (inches) in a preferred embodiment of the invention, is provided between rows of LEDs 12, which distance is chosen to maximize the optical output power of the LED array. The particular distance d is highly application specific and is contingent upon the particulars chosen for the fabrication of the array. Common power conductors, exemplary shown at 20, are suitably disposed on the surface of the base portion 10 to provide electrical connections to each of the LEDs 12.
As noted above, all LEDs 12 are suitably fabricated on a single surface 22 of the base portion 10 in the lighting array or pattern. At high packing densities, such as the high density of the preferred embodiment (0.05" apart), management of the ancillary thermal energy generated during operation of the lighting array becomes one of the main issues governing the successful use of solid-state lighting arrays for general lighting applications. So, in the preferred embodiment, an opposite surface of the base portion 10, located at 24, is disposed adjacent to and in a thermally-conductive path to a heat dissipator, illustrated generally at 30, to reduce the temperature of the LEDs within the array. In the preferred embodiment, the heat dissipator 30 is an active heat reservoir capable of freely exchanging thermal energy with the ambient environment and includes a thermal-electric cooler 32 and a finned heat sink 34. Forced air is used to facilitate the thermal transfer of energy from the finned heat sink to the ambient environment.
FIG. 2 shows a structure representative of alternatives for the heat dissipator 30. For example, the heat reservoir could be a cavity-filled structure capable of supporting fluid flow which, in turn, facilitates thermal transfer of energy from the heat reservoir to the ambient environment. It will further be appreciated that various other active and passive cooling devices are suitably implemented as the heat dissipator 30. For example, re-circulated water, Carnot cycle coolers, Stirling cycle coolers, thermo-electric coolers, and refrigerated water chillers and other active cooling components are suitably implemented.
Referring again to FIG. 1, application of electric current to the thermal-electric module 32 provides for conduction of heat from the base unit 10, through its second surface 24, to the finned heat sink 34. Thus, substantial amounts of heat may be quickly conducted away from the LEDs 12, which are relatively densely packed. Operating in this fashion, the emitting diodes can potentially be driven to temperatures below the ambient air temperature. In the preferred embodiment, chip packing density is advantageously in the order of 400 LEDs per square inch.
Also illustrated in FIG. 1 is a thermal conductivity path p, which evidences flow of heat from the LEDs 12, through the thermal-electric cooler 32, to the finned heat sinks 34. The thermal conductivity path p is also shown in FIG. 2.
A translucent window 40 is advantageously disposed adjacent to the array. Three lensing options are contemplated, each of which is particularly advantageous for specified illumination applications.
In a first option, raw un-focussed radiation fields produced by LEDs 12 of the array are available for specified applications. That is, the optical radiation emitted by the device may be used in either transmission or reflection within systems performing online process control and/or machine vision inspection applications. Parameters such as intensity, illumination geometry, spectral content, angular distribution, and relative uniformity may be controlled to optimize the illumination for a particular machine vision inspection or process control application. Moreover, a diffuser element generally, representatively shown at 43 may be employed to direct the emitted radiation to a preselected area, as those skilled in the art will appreciate. For example, the diffuser element may be a Lambertian-type diffuser 44 (ground glass, etc.), as shown in FIG. 3, or a diffractive-type diffuser 45, as shown in FIG. 4, capable of generating either circular or elliptical illumination patterns. FIGS. 3 and 4 also show graphs of intensity versus the angle θ to illustrate operational characteristics of the respective diffusers.
In a second option, as illustrated in FIG. 5, a macro lens 41 is suitably used to manipulate the complete radiation field emitted by the array to direct the light as a whole to a preselected area. By way of example, a cylindrical lens can suitably be located over top of the entire array. Preferably, the macro lens utilizes one or more of refraction, reflection, and diffraction to induce desired lensing action. In addition, as with the first lensing option, a diffuser element generally shown at 43 may be used to direct emitted light to a preselected area. For example, the diffuser element may be a Lambertian-type diffuser 44 (ground glass, etc.) (FIG. 3) or a diffractive-type diffuser 45 (FIG. 4) capable of generating either circular or elliptical illumination patterns.
Referring now to FIG. 6, a third lensing choice for use with the translucent window 40 is a plurality of lenses arranged as a lenslet array 42 to direct light generated by each of the LEDs 12 to a preselected area. The lensing action of such a lenslet array is suitably refractive, reflective, diffractive, or a combination of methods, the choice being highly application specific to induce a desired lensing action. Various lenslet arrays are well known in the art and available in the marketplace. Again, a diffuser element generally shown at 43 may be used to direct light to a preselected area. For example, such a diffuser element may be a Lambertian-type diffuser 44 (ground glass, etc.) (FIG. 3) or a diffractive-type diffuser 45 (FIG. 4) capable of generating either circular or elliptical illumination patterns.
It will be appreciated that various wiring schemes, such as parallel or serial configurations, may be utilized among the LEDs 12. This provides for a high degree of selective configureability of the LED array during the design process.
Turning now to FIG. 7, an example inspection system B employing the high-density solid-state lighting array A of FIG. 1 is provided. The system B includes a lighting control unit 50 which provides selected drive current and/or pulse duration and rate parameters to the array A.
In a pulsed-current mode, such as that advantageously used for freezing images, pulse duration and period and pulse current are electronically configurable. The lighting control unit 50 provides pulsed current to LEDs of the array A. A suitable range of such pulsed current is 0.1 amp up to 10 amps. The lighting control unit 50 also controls the pulse duration and duty cycle, or period, of array A. Pulse durations are suitably in the range of 1 to 1000 μsec. In addition, a suitable duty cycle or ratio of off-time to on-time is in the range of 2:1 to 1000:1, with 300:1 being a typical operation condition. In addition, different geometric areas within the array may be independently addressable as a function of current level and pulse duration. In one embodiment, the LEDs all emit optical radiation of essentially the same limited wavelength range so that the control unit 50 provides a configurable intensity and geometry functionality which can be utilized to optimize the emitted radiation fields for a given application area. In a second embodiment, LEDs of two or more emission wavelengths are disposed in the array such that the control unit 50 will provide to the array a configurable intensity, geometry, and spectral content functionality to be utilized to optimize the emitted radiation fields for a given application area.
In a continuous mode, the drive current to the LEDs is an electronically configurable parameter and the lighting control unit 50 provides controlled continuous current to the individual LED's in the range of 1 to 200 mA. In addition, different geometric areas within the array may be independently addressable as a function of current level. In one embodiment, the LEDs all emit optical radiation of essentially the same limited wavelength range so that the control unit 50 provides a configurable intensity and geometry functionality which can be utilized to optimize the emitted radiation fields for a given application area.
The lighting control unit 50 operates under the direction and control of a suitable computer system 52. A camera or image acquisition means is illustrated generally at 60. It will be appreciated, however, that additional cameras, such as that 60', are also suitably utilized. Camera or cameras 60 are trained onto an inspection area 62 which is selectively illuminated by the array A under control of the lighting control unit 50 and the computer 52. Images of a specimen 54 disposed in the illumination area 62 are acquired by the camera or cameras. Such images are communicated to the computer system 52 for analysis. From the illustration, it will be appreciated that a series of specimens 24 may be selectively or serially communicated to the viewing area 62 by moving them along a conveyor 64, or the like.
This invention has been described with reference to the preferred and alternate embodiments. Obviously, modifications and alterations will occur to others upon the reading and understanding of the specification. It is intended that all such modifications and alterations be included insofar as they come within the scope of the appended claims or the equivalents thereof.
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A solid-state lighting unit for automated visual inspection includes a high-density array of light emitting diodes. The packing density of said diode array being limited only by the physical size of the light emitting diode chips and the ability to perform die and wire bond operations on the bare chips. Each diode is disposed on an electrically insulated, thermally conductive base unit. The base unit is, in turn, in a thermally conductive path with a heat dissipator. The provisions made to ensure a thermally conductive path from the individual light emitting diode chips to the heat dissipator combined with the high chip packing densities work together to create a solid-state lighting array capable of producing extremely high illumination fields when operated in either pulsed or continuous current mode.
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BACKGROUND OF THE INVENTION
The invention pertains to a method for reloading in a container storage space for standard containers, with a stacker crane for the containers that services the container storage space and can be controlled by a DP (data processing) system for logistical management, which can travel between the storage location of each container and a loading platform of a container transport vehicle that can drive into the region of the container storage space, wherein the stacker crane has a means of picking up the container from the loading platform and/or setting it down onto the platform, such as can be oriented with respect to the latter.
Container storage yards are required for short-term interim storage of standard containers, in order to enable the transfer of containers from one means of transport to another. Means of container transport are generally large container ships, railroad cars, trucks, trailers, or also AGVs (automated guided vehicles). At a container harbor, container ships are unloaded and the unloaded containers are temporarily kept in the container yard until further transport is possible. Vice versa, the containers are assembled and kept temporarily in a container yard of a harbor in order to be loaded subsequently onto a container ship. The land transport occurs by truck, trailer, railroad car or AGV, and in the present application the land transport is furnished by special trucks.
The large number of containers handled at a container yard requires fast and accurate loading and unloading of the means of transportation. A stacker crane transports the container from the container yard to the transport vehicle and vice versa. The stacker crane can be an automatic container stacker crane (ACS), or also a gantry crane or a one-legged gantry crane. Thus far, the placement of the container onto a means of transport by the stacker crane has been manually controlled. The stacker crane consists of a bridge and a trolley which can travel on it, while the bridge can travel on rails. The placing of the container suspended from the crane onto a transport vehicle is manually controlled by an operator. For the loading, an operator present in the parking position drives the container by means of the stacker crane into the vicinity of the transport vehicle, and then by slow “approach” he positions the container exactly on the transport vehicle. The approach involves repeated left/right and forward/backward moving of the ACS, as well as the lowering of the container, controlled and monitored by the operator on site. Likewise, when unloading the transport vehicle, the stacker crane is slowly brought up to the container manually by an operator, so that the crane can pick it up.
The large number of containers handled within a container yard necessitates a smooth, error-free, speedy, economical and long-lasting work process. In addition, it is desirable to increase the throughput of containers, i.e., the number of containers handled per unit of time. This will reduce the parking time for containers inside the container yard, the layover time for container ships, and the stopping time for the land transport vehicles. At the same time, this implies a shortening of the length of transport for the containers.
From European patent application EP 1 043 262 A1 there is already known a method for handling of standard containers at a container yard. This container yard has a controllable stacker crane for the containers, which can travel between a storage position for the container and a transport vehicle with a loading platform for the container. The stacker crane is provided with a means of picking up the load in order to set the container down on the loading platform or pick it up from the platform, such as can be oriented with respect to the container and the loading platform. The stacker crane also has a horizontally moveable trolley with a lifting mechanism, from which is suspended the means of picking up the container. On this load suspension device is arranged a sensor in the form of a video camera system, so as to automatically place the load suspension device on the container or pick up the container from the loading platform. Furthermore, a second sensor also in the form of a video camera system is fastened to the load suspension device, in order to adjust the stacker crane. The reference point for this is a wall with optical elements, which is arranged in the region of the parking place of the transport vehicle.
Furthermore, there is also already known from the international patent application WO 01/81233 A1 a system for orienting a load suspension device for containers. The load suspension device, designed as a spreader, has a CCD camera in the region of its twist locks for fastening the spreader to the corner points of a container. Thanks to the video signal obtained from the camera, an operator can thus set this spreader down in true position on a container in relation to its support points. This system can also work automatically in conjunction with a DP system.
SUMMARY OF THE INVENTION
The underlying problem of the invention is to achieve a high throughput of containers within a container yard, to lower the costs and to reduce the down time in case of defects, while at the same time boosting the economy of the container handling yard.
This problem is solved according to the invention by the indicated method for loading of transport vehicles with standard containers per claim 1 , by the indicated method for unloading of transport vehicles with standard containers per claim 2 , and by the indicated methods for adjusting the position of a stacker crane according to claims 17 and 19 .
The illustrative embodiments provide quick and flawless handling of the loading and unloading process of transport vehicles, made possible by automation. In the present application, the constantly recurring identical loading and unloading sequences are broken down into work steps and each of them is automated. The sequence of individual automated work steps with no interruption in time, such as require a shorter time to accomplish than the manual steps, and the mistake-free processing achieve a beneficial shortening of the time of the loading and unloading process and thus also boost the throughput of the containers handled.
The loading of a transport vehicle with a container occurs by the stepwise working of steps a) through f) of claim 1 . Carrying out the work steps results in a shortening of the loading time of transport vehicles for standard containers, resulting in boosted throughput of the container handling yard. The resulting profitable time savings of the loading process comes from the individual savings accomplished by automating the work steps. At the same time, the number of mistake situations is reduced, which likewise has profitable impact on the throughput.
The unloading of the transport vehicle loaded with a container is described by the sequential working of steps a) through f) of claim 2 . The carrying out of the work steps produces a shortening of the unloading time of transport vehicles for standard containers, leading to an increased throughput of the container handling yard. The resulting profitable time savings of the unloading process consists of the individual savings achieved by automating the work steps. At the same time, the number of mistake situations is reduced, which likewise has profitable impact on the throughput.
It is advantageous that the transport vehicle and possibly the container being unloaded are identified and the thus-generated data are transmitted to the DP system of the logistical management. At the same time, the DP system of the logistical management generates a loading order or unloading order for the stacker crane. This loading order contains the job for the stacker crane to pick up the container being loaded in the container yard and put it down on the loading platform of the transport vehicle, so as to load the transport vehicle in this way. This unloading order contains the job for the stacker crane to pick up the container being unloaded from the transport vehicle and store it in the container yard. The time advantage created by having parallel work steps contributes to shorten the duration of the loading process, as does the fewer mistakes when detecting and transmitting the vehicle data.
Furthermore, the illustrative embodiments, identification points defined by means of a calibrated camera system on the loading platform of the transport vehicle or the container and their coordinates are transmitted to the DP system of the logistical management. From the identification points, the DP system determines the coordinates of the means of fastening of the transport vehicle or of the container being unloaded (the corresponding system of coordinates describes at least a space reached by the fastener of the load suspension device of the stacker crane). This method enables a quick and error-free detection of the position of the fastener for the container or that of the container itself, contributing to reduce the loading time for a transport vehicle.
In the illustrative embodiments, the DP system of the logistical management compares the coordinates of the identification points with data about the container being loaded, which is stored in the DP system, and determines the fastener being assigned to this container and the position coordinates on the loading platform of the transport vehicle. The coordinates stored in the DP system as to the size of the container can be compared in good time with the coordinates determined for the fastener of the transport vehicle. If the size of the loading platform of the transport vehicle is sufficient for the container being loaded, the fastener of the transport vehicle to be assigned will be determined. In the event that the loading platform of the transport vehicle is not large enough for the container being loaded, a premature termination of the loading process/loading order can occur, or the time-intensive picking up of the container from the container yard by the stacker crane can be prevented in good time, which represents a considerable time savings.
After the successful detecting of the coordinates of the fastener, the loading process can begin at once for the transport vehicle located in the parking position, For this, the stacker crane travels under computer control with the container being loaded above the loading platform of the transport vehicle, overlapping it exactly, and above the position coordinates. The immediate and exact positioning of the stacker crane above the transport vehicle reduces the duration of the loading process thanks to elimination of the manual “approach”.
In the illustrative embodiments, the DP system of the logistical management determines the fastener and position coordinates of the container from the identification points. This enables a quick and error-free calculation of the position coordinates, for the immediate starting of the unloading order for the transport vehicle.
For this, the stacker crane travels under computer control above the container, overlapping it exactly, and above the position coordinates. The immediate and exact positioning of the load suspension device above the container being unloaded reduces the time of the unloading process by eliminating the manual “approach”.
The fastener of the loading platform or of the container may be detected by means of a calibrated camera system mounted on the stacker crane, and the load suspension device or the container is moved so that the fastener of the container or of the load suspension device stands congruently above the assigned fastener of the loading platform or of the container. This enables a rapid, error-free, and correct orientation of the container with respect to the loading platform or that of the load suspension device with respect to the container. In contrast with the previous method, the time-intense “approach” of the container or the load suspension device by an operator present in the parking position is eliminated. It is advantageous that the visual monitoring can thus occur from a remote operator, who watches the picture of at least one camera. Likewise, the uninterrupted sequence of the individual process steps helps reduce the loading time.
As a result of precise orientation of the container with respect to the loading platform, the container can be put down on the loading platform of the transport vehicle in such a way that the fastener of the container mate with the corresponding fastener of the loading platform at the end of the lowering process. The disadvantageous “approach” of the load suspension device with the container, guided by an operator present on site, is eliminated and thus produces a beneficial timesavings. The container is deposited by the load suspension device on the transport vehicle and released. The loading job of the stacker crane is finished.
As a result of fast and exact orienting of the fastener of the load suspension device with respect to the container, the load suspension device can be brought up to the container in such a way that the fastener of the load suspension device mate with the fastener of the container. The disadvantageous “approaching” of the load suspension device to the container, guided by an operator, is eliminated and thus produces an advantageous time savings. The container is removed from the transport vehicle and can be unloaded by the load suspension device, which then stores it temporarily in the container yard. The unloading job of the stacker crane is thus finished.
In the illustrative embodiments, an operator does not have to be on site before, during and after the loading or unloading process. Thus, an operator is available for other activities.
In the illustrative embodiments, the transport vehicle and possibly the container being unloaded are identified by means of a camera system. By elimination of visual and manual identification, the resulting data are transmitted faster and free of error to the DP system of the logistical management.
For detection of the coordinates of the identification points of the loading platform or of the container, an operator supported by a user-defined interface on a monitor screen of the DP system of the logistical management may use a marking mechanism to select the identification points of the loading platform or of the container on the user-defined interface. The user-defined interface shows the image of the camera system. An operator who selects the identification points of the loading platform or of the container of the transport vehicle or container represented on the user-defined interface with the marking mechanism, contributes to the error-free detection and quick calculation of the coordinates of the fastener of the loading platform of the transport vehicle.
Another automation technique which reduces the loading time or unloading time can be accomplished in that the coordinates of the identification points of the loading platform or of the container are automatically detected by a computer system and transmitted to the logistical management.
The process step described in claims 1 and 2 for determination of the position coordinates can be implemented in at least two different ways. First, the coordinates of the loading platform or of the container of the transport vehicle can be detected in the loading and unloading zone. At this time, the transport vehicle is already identified and the assigned container is likewise known by virtue of the loading order. This allows the DP system of the logistical management to recognize early on whether the transport vehicle is suitable to accommodate the container being loaded. If the fasteners of the loading platform of a transport vehicle are successfully assigned, the loading process will continue; otherwise, the loading process, if already started, will be interrupted.
In the event that the detection of the coordinates of the loading platform of the transport vehicle occurs in the final loading and unloading zone, the position coordinates described by the vertical position of the loading platform or the upper edge of the identification points of the container and by the intersection of the diagonals of the identification points of the loading platform, are the absolute target position of the container. The arrangement is thus extremely adroit and enables a quick and thus time-saving positioning of the automatic stacker crane with the container or without, above the loading platform being loaded or above the container being unloaded.
In the other embodiment of the invention of the process step described in claim 1 for determining the position coordinates, the detection of the coordinates of the loading platform of the transport vehicle or of the container in this case occurs in the identification zone. This allows the DP system of the logistical management to recognize early on whether the transport vehicle is suitable to accommodate the container being loaded. Once the fasteners of the loading platform of the transport vehicle are successfully assigned, the loading process will continue; otherwise, the loading process, if already started, will be interrupted.
Since the detection of the coordinates of the loading platform of the transport vehicle occurs in the identification zone, the coordinates detected for the loading platform refer to the transport vehicle. Thus, the vertical position of the loading platform and the intersection of the diagonals of the identification points of the loading platform describe the relative target position of the container.
The position coordinate of the container is described by the vertical position of the upper edge of the identification points of the container and by the intersection of the diagonals of the identification points of the container, which describes the relative target position of the container. By selecting the upper edge of the identification points (fastener) of the container as an element of the position coordinate, one can also unload standard containers not having a cover, such as open-top containers, tank containers and/or flat containers. Thus, the favorable choice of the position coordinate enables an adroit and thus time-saving positioning of the automatic stacker crane above the container being unloaded.
The coordinates of the loading platform or of the container that are detected in the identification zone refer to the transport vehicle and consequently describe the relative target position of the container or of the load suspension device. Advantageously, the position coordinate is described by the absolute target position of the container or the load suspension device, which is composed of the coordinates determined by means of a camera for the transport vehicle located in the parking position and the relative target position of the container or of the load suspension device. The coordinates already detected in the identification zone are linked to the position of the transport vehicle identified in the parking position by the DP system of the logistical management. The result of this linkage is the position coordinate, which is the absolute target position of the container or of the load suspension device. This enables an adroit and thus time-saving positioning of the automatic stacker crane with the container above the loading platform being loaded or the container being unloaded, as is described hereafter.
Regardless of where the detection of the coordinates occurs, a wrong position of one or more fasteners will be evident on the user-defined interface of the DP system. The operator recognizes the wrong positions and consequently notifies the driver of the transport means. He will correct any wrong positions of the fasteners in good time.
Regardless of the way chosen to detect the coordinates, the advantageous choice of the position coordinate will enable the load suspension device to move the container or the load suspension device into the range of the loading platform or of the container, so that the intersection of the diagonals of the fastener of the container or of the load suspension device stands congruent and plumb above the intersection of the diagonals of the fastener of the loading platform or of the container. The container or the load suspension device hanging from the stacker crane is thus situated in the middle above the loading platform or the container and must consequently be oriented in the possibly next work step by a rotary movement of the container hanging from the load suspension device or of the load suspension device. For this, the stacker crane need not travel any further, i.e., the bridge of an ACS and the trolley moving on it have already reached their exact final loading position. In the illustrative embodiments, the stepwise approach of the load suspension device, guided by an operator, is eliminated. This procedure enormously simplifies the positioning of the load suspension device or the stacker crane and thus contributes to an extremely large reduction in the required loading time or unloading time.
In the illustrative embodiments, simple watching of the loading process or unloading process by an operator is obtained by a second user-defined interface with four quadrants, each of them representing a pair of fasteners, while each pair consists of a fastener of the loading platform or container, projected by an image from the camera system, and the associated fastener of the container or load suspension device, projected by a superimposing of a computer-calculated contour of the container or the load suspension device and of the fastener onto the image. Thus, the operator comfortably watches the loading process or unloading process, without having to be present at the parking position.
In the illustrative embodiments, any deviation between the position of the container being loaded or the load suspension device and the position of the loading platform or the container being unloaded can be determined in the DP system of the logistical management for a fine-tuned positioning, in that the second user-defined interface of the logistical management has a marking mechanism with which the operator selects at least one identification point of the loading platform or of the container. The thus-determined precise orientation of the loading platform or of the container is used to orient the container with respect to the loading platform or the load suspension device. A deviation of the orientations recognized by the DP system of the logistical management results, during the next step of the work sequence, in a correcting of the position of the container or the load suspension device. The simple detecting of the position of the loading platform or container, the direct availability of the data in the DP system of the logistical management, and the excluding of errors from the data result in an exceptional time savings.
In the illustrative embodiments, any deviation in position of the container being loaded or the load suspension device with respect to the position of the loading platform or the container being unloaded is automatically recognized by a computer system for fine positioning.
When a deviation exists in the position of the container being loaded or the load suspension device with respect to the position of the loading platform or the container being unloaded, the container or the load suspension device is turned so that the fastener of the container or of the load suspension device stand congruently and plumb above the fastener of the loading platform or container. Such a fast and correct orienting of the container with respect to the loading platform or that of the load suspension device with respect to the container occurs automatically, based on the computed deviation. A tilting of the transport vehicle in its lengthwise and/or transverse direction, caused for example by uneven ground, does not have harmful impact on the loading process. The stepwise approach of the load suspension device with or without the container relative to the loading platform or the container may be eliminated, which produces an exceptional reduction in the time required for the loading or unloading of a transport vehicle.
The swift setting down and releasing of the container from the load suspension device or the swift approach of the load suspension device to pick up the container and the locking together of the fastener is guided by an operator or automatically by a computer system. Since the container or the load suspension device is precisely located above the loading platform or the container and is correctly oriented, and the DP system has determined the vertical position of the loading platform or the container, an immediate and continuous motion for depositing the container or the load suspension device can be carried out, and it can be concluded sooner than the manual “approach”. The locking together of the fastener of the container and those in the loading platform completes the deposit of the container. After the load suspension device is no longer loaded with the container, which is indicated by the triggering of pressure sensors, the container can be released from the load suspension device and fastened to the transport vehicle. The locking together of the fastener of the load suspension device and those in the container completes the picking up of the container. The container is fastened to the load suspension device and the stacker crane places it in the container yard for temporary storage. Thus, the unloading job order is complete.
The continuous sequence of process steps enables a fast loading and unloading of a transport vehicle. The time saved in this way is available for other loading or unloading processes. Consequently, the throughput of containers handled in a container yard can be increased, which represents an efficiency boosting and likewise a reduction in the transport time of the transported freight.
Furthermore, an adjustment of a stacker crane may be possible at any time and with little expense by using the method described in claim 16 . It should be kept in mind that geometrical deviations in a camera provided for use on the stacker crane can be produced by structural part tolerances, manufacturing tolerances, irregularities in the lens and/or optical errors, and can be circumvented by a calibration done prior to use of the camera. During operations, the image from a camera used on the stacker crane may be continuously corrected by means of a correction algorithm obtained from the calibration. Thus, the correction algorithm specific to the camera is applied to each image of a camera by the DP system of the logistical management. Consequently, each camera used has substantially identical optical properties if its corresponding correction algorithm is applied. In addition, the preliminary calibration allows the DP system of the logistical management to remotely measure the familiar objects being viewed, in accordance with the laws of optics.
By using this calibrated camera, a further adjustment of the position of the stacker crane can now be carried out. Per claim 16 , the stacker crane first moves over a reference point situated at any given position within the container yard, so that at least one camera of the camera system catches the reference point. The DP system of the logistical management compares the new position of the reference point, calculated from the camera image, with its known position of the reference point and, if any deviation is present, it determines an offset for the stacker crane. Under the assumption that the reference point in general does not shift, a correction can be made in the position coordinate of the stacker crane by the DP system of the logistical management adding the offset to the calculated position data of the stacker crane. This may be useful in the case of a length change in the running rails of the automatic container stacker (ACS) crane, which is an expansion of length in summer and a contraction of the running rails in winter due to the temperature. Since the DP system of the logistical management may determine the position in terms of an absolute length measurement of the distance traveled by the stacker crane, the temperature-sensitive arrangements and positions that the stacker crane actually travels can be displaced from the position calculated by the DP system of the logistical management. Thus, it may be possible to correct an erroneous calculation of the position of the stacker crane caused by these factors of influence.
The stacker crane can be quickly adjusted as often as desired and at any given time.
Several reference points can be arranged within the container yard. After the stacker crane has placed itself above one of these reference points, the DP system of the logistical management can compare the position of the reference point already known to it with the new position calculated from a camera image, and calculate any offset for the stacker crane associated with the reference point. In the event that several reference points are located along the linear path of the stacker crane and one of the offsets of these reference points determined in a narrow time domain has a nonsystematic deviation, this indicates ground shifting in the vicinity of the affected reference point, which is afterwards introduced into the calculations for positioning of the stacker crane by the DP system of the logistical management as a correction. In this way, one can avoid any wrong interpretations of length expansions.
The container yard may have a super-reference point, with which each camera on the stacker crane can be adjusted relative to it. Replacing a camera mounted on the stacker crane due to a technical defect, etc., requires the onetime adjustment of a newly installed camera on the stacker crane. By using the super-reference point, the DP system of the logistical management can determine a correction vector and assign it to a new camera mounted on the stacker crane. The repair and adjustment time and thus the down time of the stacker crane are profitably shortened. The super-reference point may be situated at one position in the container yard that is independent of outside influences of the above described kind. The stacker crane travels with the newly installed and already calibrated camera above the super-reference point so that the newly installed camera detects it. The DP system determines the position of the super-reference point and compares the data thus obtained with the already stored data about the super-reference point. If there is any deviation in the data, a correction vector will be assigned to the newly installed camera, and it will be used during each position computation done on the basis of this camera. The timesaving achieved due to the swift adjustment of the newly installed camera on the stacker crane can be used profitably for loading and unloading processes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan overview of a container handling yard,
FIG. 2 is a side elevation of an identification zone for detection of transport vehicles,
FIG. 3 is a top plan section of a container handling yard, container storage space and parking position,
FIG. 4 is a side elevation of the area shown in FIG. 3 ,
FIG. 5 is a side elevation representation of the viewing angle of the camera placed in the parking position,
FIG. 6 is a view of first user-defined interface,
FIG. 7 is a side elevation representation of the viewing angle of the camera arranged on the side of the automatic container crane,
FIG. 8 is a side elevation representation of the viewing angle of the camera arranged on the side of the automatic container crane,
FIG. 9 is a view of a second user-defined interface, during a loading process,
FIG. 10 is a view of a user-defined interface at the end of a loading process,
FIG. 11 is a side elevation another embodiment of an identification point,
FIG. 12 is a top plan view of another section of a container handling yard, container storage space and parking position,
FIG. 13 is a side elevation of another representation of the viewing angle of the camera arranged in the parking position,
FIG. 14 is a top plan view of representation of the arrangement of a reference point.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an automated container terminal 24 for containers 1 , where trucks 7 ( FIG. 2 ) are loaded and unloaded at the land side. In an identification zone 25 , arriving and departing trucks 7 are identified and/or surveyed. An arriving truck 7 is identified and the data thus generated, which are required for the loading and unloading, are transmitted to the DP (data processing) system (not shown) for logistical management. After this, the truck 7 moves to the loading or unloading zone 6 by roadways 26 .
FIG. 2 shows the cameras 27 arranged in the identification zone 25 , which are used to detect the truck 7 from all sides. The license number 28 of the truck 7 and possibly the license number 29 of the trailer 7 . 1 are automatically detected by the cameras 27 . Likewise, the identification number 30 of the container 1 will also be detected in the case of loaded trucks 7 . All information regarding the truck 7 , the trailer 7 . 1 , and possibly the container 1 will be transmitted to the DP system of the logical management and be available in the system at all times and can be called up by an operator (not shown).
In the automatic container storage space 2 , as depicted in FIGS. 3 and 4 , the containers 1 are kept in stacks. The automatic stacker crane 3 consists of a mobile trolley 3 . 2 , which can travel on a bridge 3 . 1 , while the bridge 3 . 1 can travel on the crane track 4 . During the loading process, the container 1 is rigidly connected to the moveable mast 3 . 3 of the moveable trolley 3 . 2 . On the mast 3 . 3 is situated the load suspension device 3 . 4 of the stacker crane 3 , which accommodates the container. The automatic stacker crane 3 is coupled to the DP system of the logistical management and can thus reach every possible coordinate within the travel zone at any time. The coordinate system (not shown) describes a space which is reached by the load suspension device 3 . 4 of the automatic traveling stacker crane 3 . In place of an ACS, one can also use gantry cranes or one-legged gantry cranes.
The automatic container storage space 2 is bounded off from the loading and unloading zone 6 by a border 5 , which can be a fence or a wall. In the loading and unloading zone 6 , the trucks 7 are each positioned in a parking position 8 . FIGS. 3 and 4 show trucks 7 that have been backed into a parking position 8 , which was assigned to them. The parking positions 8 have concrete gutters 8 . 1 at the sides, which facilitate the backing in of the trucks 7 when parking, since the wheels 9 of the truck 7 are guided in this way. The parking process is completed when the truck 7 backs up and its wheels 9 strike against the cross struts 8 . 2 bounding the parking position 8 .
Each parking position 8 is outfitted with a fixed and calibrated camera system 10 , which is located above the boundary 5 ( FIG. 5 ). The viewing angle 11 of the camera 10 is chosen so that all loading platforms 31 of the truck 7 and any containers 1 located thereupon are completely detected. Thanks to this viewing angle 11 of the camera 10 , an operator at a monitor 12 ( FIG. 6 ) can observe the parking process.
FIG. 6 shows the monitor 12 with the image of the camera 10 , by which the operator can observe and control the parking process of the truck 7 and the loading and unloading process. For the loading of the truck 7 in the parking position 8 , the position of the loading platform 31 of the truck 7 has to be measured. For this, a marking mechanism such as a crosshair 14 is superimposed on the image of the camera 10 , with which the operator can select identification points. These identification points are the fasteners of the loading platform 31 of the truck 7 , the so-called twist locks 13 . The coordinates of the twist locks 13 are transmitted to the DP system of the logistical management in order to calculate the position coordinate of the loading platform 31 . The DP system of the logistical management calculates the diagonals 16 of the twist locks 13 and their point of intersection 17 . The intersection 17 describes the vertical position 15 of the loading platform in the system of coordinates. This computation is made possible by a previous calibration of the fixed installed camera 10 , whose exact position and viewing direction is known.
The container 1 located on the rigid mast 3 . 3 of the stacker crane 3 , as depicted in FIG. 7 , is positioned above the loading platform 31 of the truck 7 so that the point of intersection of the diagonals of the fastener of the container 1 stands congruently and plumb above the point of intersection 17 of the diagonals 16 of the fastener of the loading platform 31 of the truck 7 . Thanks to the cameras 18 arranged on the stacker crane 3 and thanks to the chosen type of positioning of the container 1 being loaded above the loading platform 31 , the viewing angle 19 of the camera 18 can be restricted, as depicted in FIG. 8 . Due to the different container sizes of 20 ft., 30 ft., 40 ft. to 45 ft., two viewing angles 19 . 1 and 19 . 2 are required left and right, disregarding the middle zone of the container 1 . In terms of the coordinates of the point of intersection 17 of the diagonals 16 of the loading platform 31 , a viewing range of the camera system 42 . 1 from −7 m to −3 m and a viewing range of the camera system 42 . 2 from +3 m to +7 m is necessary. Only in these areas are there twist locks 13 of the loading platform 31 adapted to the container 1 .
FIG. 9 shows the four-part user-defined interface 20 of the DP system of the logistical management. Each quadrant shows one image segment, which is generated by at least one of the cameras 18 arranged on the side of the stacker crane 3 . For redundancy reasons and reliability considerations, the four image segments can be generated from the image of a camera, or also from two images of two cameras arranged at the side. It is likewise possible to implement a solution that provides one camera for each image segment. Each image segment shows the fastener, the twist locks 13 of the loading platform 31 . The operator can recognize a wrong position for the twist locks 22 and then use an intercom system to ask the driver of the truck 7 to correct this wrong position. The computer-calculated contours of the container 23 are superimposed on the image, showing the operator the actual position of the container 1 . The orientation of the container 1 with respect to the loading platform 31 is accomplished by the operator using a marking mechanism, such as a crosshair 24 , to once again select the fastener or twist locks 13 of the loading platform 31 . The coordinates of the fastener of the loading platform 31 are once again transmitted to the DP system of the logistical management. The actual orientation of the loading platform 31 is calculated from this. Any deviation between the orientation of the container 1 and the orientation of the loading platform 31 is determined by the DP system of the logistical management and the container 1 is rotated on the mast 3 . 3 by means of the load suspension device 3 . 4 so that all fasteners of the container 1 stand congruently and plumb above the fasteners of the loading platform 31 .
During the lowering process, the computer-calculated contour 23 of the container is newly calculated at any time and superimposed on the image frozen at the start of the lowering process, as represented in FIG. 10 . At the end of the lowering process, the fasteners of the container 1 engage with the fasteners of the loading platform 31 of the truck 7 . The operator watches and controls the loading process on the monitor as the container 1 is set down.
Another method for detecting the identification points of the loading platform 31 of a truck 7 or the identification points of a container 1 is shown by FIGS. 11 to 13 . The known process steps of the previously described process are rearranged here.
FIG. 11 shows a modified identification zone 25 , in which the arriving truck 7 including a possibly present container 1 is identified. The identification of the truck 7 involves the recognition of the license plate 28 , 29 of the transport vehicles and the identification number 30 of the possibly present container 1 by means of the cameras 27 arranged at the identification zone 25 , which are connected to the DP system of the logistical management and transmit the so-generated data to it. In addition to the work step described in FIG. 2 , the possibly present container 1 and/or the empty loading platform 31 of the truck 7 are then measured. The truck 7 is detected from the side 32 and from above (top view) 33 by means of the camera 27 . The detection of the identification points of the loading platform 31 (or container 1 ) as described in FIG. 6 does not occur in the loading and unloading zone 6 , contrary to FIG. 6 , but rather in the identification zone 25 . The course of the detection of the identification points remains identical. At the same time, there is an automatic measuring of the height 34 , 35 of the fastener being used by the camera 27 . The coordinates found are transmitted to the DP system, and these represent the relative target position of the container being unloaded, since they pertain only to the truck 7 . The driver of the truck 7 , after a successful identification and measurement of the truck 7 , receives an access authorization in the form of a magnetic card or chip card (not shown). The magnetic card also contains all relevant data concerning the handling order.
The driver drives the truck 7 to a loading and unloading zone 6 assigned to him ( FIG. 12 ) and backs his transport vehicle up into any desired parking position 8 within the loading and unloading zone 6 . During the parking process, as represented in FIG. 13 , an object recognition is started in the DP system of the logistical management by means of a camera 36 arranged in the parking position 8 , which identifies the truck 7 and also classifies it geometrically in the system of coordinates, not represented. The information from the camera 36 arranged at the border 5 allows the DP system of the logistical management to exactly recognize the truck 7 in terms of its identity and position: its distance 37 from the border 5 , a left/right offset within the parking position 8 and angle of twist of the truck 7 relative to the ground 38 . Thus, after completing the parking process, the exact position of the truck 7 is known to the DP system of the logistical management.
From these coordinates, and in conjunction with the relative target position of the container 1 , the DP system of the logistical management can determine the position coordinate for the container 1 being loaded, which represents the absolute target coordinate for the container being loaded.
Next, the driver of the truck 7 goes to a reporting space 39 , in order to signal with the magnetic card his readiness for loading or unloading of the truck 7 . The DP system checks the data on the magnetic card against the data obtained from the parking position 8 of the truck and if they agree it, generates an order for the stacker crane 3 . The stacker crane 3 picks up the container 1 to be loaded from the container storage space 2 and begins the loading of the truck 7 in accordance with the method described as of FIG. 7 .
Furthermore, FIG. 12 shows a tolerance range 40 . Within each parking position 8 , the load suspension device 3 . 4 of the stacker crane 3 can only travel within this special tolerance range 40 , for safety reasons.
FIG. 14 shows a container yard 2 with a reference point 41 .
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The invention relates to an automatic method for increasing the throughput of a container reloading point or a container storage space and for reducing the loading and unloading time for a container transport vehicle. According to said method, after the identification of a container transport vehicle, the loading platform of the transport vehicle that has been parked in the parking area of the container storage space is measured. The position co-ordinates of the loading platform are determined by a data processing system. The container to be loaded is then automatically positioned by means of a crane, using the position co-ordinates of the loading platform. To align the container exactly in relation to the loading platform, the latter is measured again and any deviation in relation to the position of the container thus obtained is used for said exact alignment. The container is deposited on the platform automatically. The unloading of a container transport vehicle involves practically identical steps.
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This application is a divisional of U.S. patent application Ser. No. 11/462,739 filed on Aug. 7, 2006. This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/707,937 filed on Aug. 12, 2005, which is incorporated herein by reference.
TECHNICAL FIELD
This invention pertains to electrode catalysts for fuel cells. More specifically, this invention pertains to corrosion resistant catalyst supports for fuel cells, especially for cells having a cathode at which oxygen is reduced in air.
BACKGROUND OF THE INVENTION
Fuel cells are electrochemical cells that are being developed for mobile and stationary electric power generation. One fuel cell design uses a solid polymer electrolyte (SPE) membrane or proton exchange membrane (PEM), to provide ion transport between the anode and cathode. Gaseous and liquid fuels capable of providing protons are used. Examples include hydrogen and methanol, with hydrogen being favored. Hydrogen is supplied to the fuel cell anode. Oxygen (as air) is the cell oxidant and is supplied to the cell's cathode. The fuel cell electrodes are formed of porous conductive materials, such as woven graphite, graphitized sheets, or carbon paper to enable the fuel to disperse over the surface of the membrane facing the fuel supply electrode. Each electrode comprises finely divided catalyst particles (for example, platinum particles), supported on carbon particles, to promote ionization of hydrogen at the anode and reduction of oxygen at the cathode. Protons flow from the anode through the ionically conductive polymer membrane to the cathode where they combine with oxygen to form water, which is discharged from the cell. Conductor plates carry away the electrons formed at the anode.
Currently, state of the art PEM fuel cells utilize a membrane made of perfluorinated ionomers such as Dupont NAFION®. The ionomer carries pendant ionizable groups (e.g. sulfonate groups) for transport of protons through the membrane from the anode to the cathode.
Currently, platinum (Pt) supported on a high surface area carbon is the most effective electrocatalyst for PEM fuel cell systems. However, a significant problem hindering large-scale implementation of proton exchange membrane (PEM) fuel cell technology is the loss of performance during extended operation and automotive cycling. Recent investigations of the deterioration of cell performance have revealed that a considerable part of the performance loss is due to the degradation of the electrocatalyst. Although carbon has been considered as the most favorable catalyst support because of its low cost, good electron conductivity, high surface area, and chemical stability, corrosion of carbon supports on the cathode side of PEM fuel cells is emerging as a challenging issue for long-term stability of PEM fuel cells.
It is an object of this invention to provide a porous titanium oxide electrocatalyst support having suitable properties for a PEM fuel cell environment including suitable surface area, electrical conductivity and chemical stability.
SUMMARY OF THE INVENTION
This invention uses a porous form of titanium dioxide (sometimes called “titania”) as a high surface area support for platinum, or other suitable catalyst. Preferably, the titanium dioxide is mixed or doped with an element such as niobium to enhance the electrical conductivity of the support material. The titanium oxide is formed around removable filler particles (particulate templates), such as silica particles, that are chemically dissolved (etched) from the titanium dioxide particles to yield highly porous catalyst particle carriers. Particles of noble metal or other catalyst material are then deposited on the porous carrier material. Such a titanium dioxide carrier material is particularly useful in a catalytic electrode material in association with a proton exchange membrane in a fuel cell in which oxygen is electrochemically reduced.
In accordance with a preferred embodiment of the invention, a titanium alkoxide compound is formed as a solution or sol in an alcohol or aqueous/alcohol medium. For example, a solution or sol of titanium (IV) isopropoxide or titanium (IV) 2-ethylhexyloxide may be formed. A salt or alkoxide of a suitable dopant element may also be dissolved or dispersed in the medium. Examples of suitable dopant elements include lanthanum, manganese, molybdenum, niobium, tantalum, tungsten, strontium, vanadium, and yttrium. Also dispersed in the liquid medium are suitably sized particles (e.g. less than twenty nanometers in greatest dimension) of silica, polymer beads, or the like (preferably with the aid of ultrasonic energy). The titanium and dopant element compounds are then precipitated or gelled on the dispersed particles.
The gelled or precipitated composite material is separated from the liquid medium and dried as necessary. The composite material is heated to a suitable temperature in a controlled atmosphere, for example of hydrogen or ammonia, to form very small particles (nanometer size) of titanium dioxide doped with a suitable quantity of niobium, or the like. When the template particles consist of an organic polymer they may be removed by heating to leave pores in the agglomerated particles of titania. When the template particles are inorganic, like silica, they may be chemically dissolved from the titanium dioxide particles leaving internal and external surface pores for receiving and dispersing fine particles of catalyst metal.
The porous and doped titanium dioxide particles provide ample surface for the effective dispersion of platinum particles for use as cathodic electrode material on a NAFION® proton exchange membrane in a hydrogen/oxygen fuel cell environment. The titania carrier resists oxidative weight loss in a high temperature air environment and displays electrical conductivity.
Other objects and advantages of the invention will be apparent from a detailed description of illustrative preferred embodiments.
DESCRIPTION OF PREFERRED EMBODIMENTS
The titanium dioxide catalyst support materials of this invention have general utility in catalyst applications. Their utility includes applications as catalyst supports for catalyst particles in fuel cell electrodes. For example, these durable catalyst supports may be useful in an electrochemical fuel cell assembly including a solid polymer electrolyte membrane and a cathode that is exposed to oxygen or air. Many United States patents assigned to the assignee of this invention describe electrochemical fuel cell assemblies having an assembly of a solid polymer electrolyte membrane and electrode assembly. For example, FIGS. 1-4 of U.S. Pat. No. 6,277,513 include such a description, and the specification and drawings of that patent are incorporated into this specification by reference. In the '513 patent, carbon particles are used to carry or support catalyst particles for electrode (anode or cathode) operation. In this invention, porous and doped titanium dioxide particles are used to carry the catalyst for the electrode function.
Compounds of titanium (IV) alkoxides, such as titanium (isopropoxide) 4 or titanium (2-ethylhexyloxide) 4 , are readily available and are, therefore, suitable and even preferred for use in the practice of this invention. These compounds have suitable solubility in alcohol (ethanol) for use in this method. As summarized above, suitable dopant elements include lanthanum, manganese, molybdenum, niobium, tantalum, tungsten, strontium, vanadium, and yttrium. Atoms of the dopant element(s) may be added to promote electronic conductivity by introducing defects in the crystalline titanium oxide support material. The dopant(s) is suitably added in an amount up to about half of the atoms of titanium in the support material. Alkoxide compounds or salts of these dopant elements are available and may be used for introducing one or more dopant element(s) into the titanium oxide catalyst support particles.
For example, titanium (IV) isopropoxide and niobium (V) chloride, or niobium (V) ethoxide, are dissolved in ethanol in proportions of two atomic parts titanium per atom of niobium. Silica particles (10-15 nm in largest dimension) are dispersed in the alcohol solution or sol of titanium and niobium compounds. Silica is suitably added to the sol in an amount to provide about 1.2 parts by weight of silicon per part of titanium. As an alternative nanometer size particles of nylon or vinyl chloride may be used as pore-forming templates in the dispersion. The uniformity of mixing of the constituents of the dispersion may be enhanced by sonic vibration of the dispersion.
The solution (sol) is then acidified with aqueous hydrochloric acid to hydrolyze the titanium and niobium compounds and form a gel or precipitate of titanium-containing and niobium-containing material entraining the silica particles. The titanium containing material contains sufficient oxygen for the formation of titanium dioxide.
The precipitate or gel is separated from the liquid medium and dried. The solid material is then heated to about 1000° C. in an atmosphere of hydrogen (or suitably, ammonia) so as to form crystalline titanium dioxide doped with elemental niobium. The particles of titanium dioxide are very small, nanometer size, and the particles of silica are dispersed in the doped titanium dioxide.
The niobium doped oxide particles are chemically etched with aqueous sodium hydroxide or hydrogen fluoride to remove the pore-forming silica particles. The residue of the chemical etching is a mass of very small, pore containing, Nb-doped, TiO 2 particles where the pores are formed principally by the removal of the silica particles.
In a specific experimental example, the resulting porous TiO 2 was crystalline, contained Ti/Nb in an atomic ratio of 2, and had a BET surface area of 125 m 2 /g.
In a continuation of the experimental illustration, Pt was deposited on this Nb-doped TiO 2 using an aqueous solution of diamineplatinum (II) nitrite, Pt (NO 2 ) 2 (NH 3 ) 2 , as a precursor. The Nb-doped TiO 2 was dispersed in water at 80° C. using ultrasonic energy. The platinum precursor was also separately dissolved in 70-80° C. water with stirring. The TiO 2 dispersion and the platinum precursor solution were mixed. The pH of the resulting platinum deposition medium was adjusted to 3.0 using acetic acid and carbon monoxide gas was diffused through the medium at a rate of two liters per minute. The reaction medium was stirred at 90° C.
Hydrazine hydrate was used for reduction of the platinum and its deposition as very small particles on the niobium-doped TiO 2 particles. Hydrazine hydrate was added drop wise with stirring to the platinum deposition medium (at 90° C., pH 3, and with CO diffusion) over a period of one hour. Then the TiO 2 -containing medium with deposited platinum was cooled to room temperature. The reaction product of platinum deposited on niobium-doped titanium dioxide particles was filtered through a 0.45 micrometer pore-size cellulose nitrate membrane, washed with distilled water, and dried overnight in a vacuum oven at 50° C.
In this example platinum was deposited at 72 weight percent on porous niobium doped titanium dioxide and the resulting catalyst was tested with a gas phase accelerated thermal sintering method intended to induce oxidative corrosion of the catalyst. The test was conducted at 250° C. for 30 hours under an atmosphere, by volume, of 0.7% O 2 , 8% H 2 O, and the balance helium. Two commercial platinum-on-carbon catalysts were subjected to the same corrosion testing for comparison. Table 1 records the mass loss resulting from the platinum-on-titanium dioxide catalyst produced in accordance with this invention and the two comparison carbon supported platinum catalysts.
TABLE 1
Mass Loss Comparison
Catalysts
Pt loading
Mass Loss
Pt/TiO 2 (no Nb)
42%
−1.1%
Pt/TiO 2 (Nb/Ti = 1/2)
72%
−4.4%
Pt on carbon (1)
46.6%
−55.8%
Pt on carbon (2)
45.9%
−76.2%
It is seen that the titanium oxide supported catalysts survives an oxidizing environment better than the carbon supported catalyst.
The above porous, niobium-doped titanium oxide supported platinum catalyst was further tested for its oxygen reduction activity. The catalyst sample was prepared for electrochemical measurement by a special method (mixing and sonication in a suspension) to form an ink for application to a rotating disk electrode (RDE). The suspension contained the platinum on doped-titanium dioxide support (designated 41305 TJ) and a commercial electrically conductive particulate carbon dispersed in isopropanol and water. The dispersion also contained a 5% solution of NAFION® ionomer in water.
The supported platinum and carbon containing mixture was put into a sealed 60 ml glass bottle. The content was subsequently mixed by shaking and sonicated for 2-4 hours. Once a homogeneous ink suspension was formed, 10-20 micro liters of the suspension were dispensed on a glassy carbon electrode surface. After drying at room temperature, the electrode was put on the Rotating Disk Electrode (RDE) device for activity measurement (in micro-amperes per square centimeter of platinum at 0.9V). The resulting dried catalyst on the electrode contained 52.6 wt. % Pt.
A sample of platinum on non-doped TiO 2 was prepared for comparison testing. The platinum on non-doped TiO 2 (sample 0131005TJ) was applied as in ink to a RCE for comparative electrode activity measurement by the technique described above. Also, a second platinum on niobium-doped TiO 2 catalyst was prepared (sample 061705KV). This sample contained niobium in an amount of 5% of the titanium and the platinum loading on the electrode was lower (33.4%) than sample 131005TJ.
In the electrode activity tests the electrode was rotated at 1600 RPM in the 0.1M HClO 4 electrolyte at 60° C. with a flowing, saturated oxygen atmosphere at one atmosphere. The electrode voltage scan rate was 5 mV/s over a voltage range of 0-1V.
Table 2 summarizes the specific oxygen reduction activities of two illustrative platinum-on-doped titanium dioxide support catalysts and like data obtained using the non-doped TiO 2 sample and two commercial platinum-on-carbon comparison catalysts.
TABLE 2
Specific activity
Catalyst
Pt (wt %)
Type
(uA/cm 2 Pt at 0.90 V)
0131005TJ
27.8
Pt/TiO 2 (no Nb)
153
041305TJ
52.6
Pt/Nb—TiO 2 (1:2)
548
061705KV
33.4
Pt/Nb—TiO 2 (5%)
494
Pt/C (3)
46.4
Pt Co/C
298
Pt/C (4)
46.5
Pt/HSC
172
It is seen that the niobium-doped titanium support particles with platinum catalyst provided highly suitable specific electrode activity in the tests. The specific activities of the tow samples in uA/cm 2 Pt at 0.90V were higher than either of the platinum on carbon electrocatalysts or the platinum on non-doped TiO 2 electrode material.
While the invention has been illustrated by certain preferred embodiments, these illustrations are intended to be non-limiting.
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Titanium oxide (usually titanium dioxide) catalyst support particles are doped for electronic conductivity and formed with surface area-enhancing pores for use, for example, in electro-catalyzed electrodes on proton exchange membrane electrodes in hydrogen/oxygen fuel cells. Suitable compounds of titanium and a dopant are dispersed with pore-forming particles in a liquid medium. The compounds are deposited as a precipitate or sol on the pore-forming particles and heated to transform the deposit into crystals of dopant-containing titanium dioxide. If the heating has not decomposed the pore-forming particles, they are chemically removed from the, now pore-enhanced, the titanium dioxide particles.
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TECHNICAL FIELD
[0001] The present disclosure relates to laser processing a workpiece and, more particularly, to a method of and an apparatus for laser drilling holes in multilayer electronic substrates for the purpose of forming vias to permit electrical interconnections between the layers. Specifically, the disclosure relates to laser drilling holes with selectable taper in a workpiece.
BACKGROUND INFORMATION
[0002] Nearly all currently manufactured electronic products, including devices such as computers, cell phones and other consumer electronics, are constructed by attaching electronic components to substrates. Electronic components include integrated circuits, passive devices, displays and connectors. Substrates function to hold the electronic components in place and provide electrical connections between the components with desired mechanical, thermal and electrical properties. Substrates typically include an electrically non-conductive layer or layers combined with electrically conductive elements that function electrically in cooperation with the electronic components. Materials that form the non-conductive layers can include crystalline materials such as silicon or sapphire, amorphous materials such as non-crystalline silicon or glass, sintered ceramic materials such as aluminum oxide, or organic materials such as FR-4, polyimide, or ABF, or combinations of the preceding materials. Conductors are formed on or in the substrate by processes including photolithographically depositing conductive materials such as polysilicon, aluminum or copper, depositing conductive inks using screen print or ink jet technologies, or laminating and/or patterning conductive layers on or in the substrate.
[0003] What these processes have in common is the need to interconnect electrical conductors that may be separated by layers of electrically nonconductive material. Electronic substrates are typically made up of conductive and nonconductive layers arranged in a planar fashion. FIG. 1 shows a schematic diagram of a multilayer substrate made up of electrically conductive or inorganic layers 10 , 12 and 14 , separated by electrically nonconductive or organic layers 20 , which may contain one or more reinforcing layers 24 .
[0004] The performance of a laser via drilling system is evaluated according to several criteria, including throughput, accuracy and via quality. Factors that determine via quality include location, shape, debris and taper. Taper refers to the shape and angle of the via side walls. Side wall taper is important because, following drilling, vias are typically plated with an electrically conductive material such as copper to electrically connect layers of a multilayer substrate. High taper, where the walls are relatively parallel, allows the plating to be of high quality and durable.
[0005] Drilling high quality vias with a specific taper is highly desirable because it makes it easy to provide good electrical and mechanical contact between the conductor at the bottom of the via and the conductor at the top. Furthermore, providing a good, textured surface, free from debris or remaining organic “smear,” enables good electrical contact between the bottom conductor and the plating, further improving the via quality. At the same time, it is desirable to maintain as high a system throughput as possible, meaning that as little time as possible should be taken to drill a via. Given a maximum repetition rate of a laser, this usually means drilling the via with as few pulses as possible, consistent with desired taper and quality. And finally, it is desirable to deliver a system and method to accomplish the above at a reasonable cost and complexity.
[0006] U.S. Pat. No. 6,479,788 of Arai, et al., assigned to Hitachi Via Mechanics, Ltd., attempted to solve this problem by varying the pulse width of substantially square pulses as the via is being drilled. The difficulty with this approach is that it requires very precise control of the laser pulses at very high speed. Since today's lasers may exceed 30,000 pulses per second, this system requires control and optics capable of modifying pulses with possible nanosecond resolution at very high power at very high pulse rates, which likely reduces the system reliability and increases cost. It would be desirable then, to achieve the desired taper, quality and throughput without requiring elaborate real time control of each pulse.
[0007] There is a continuing need for an apparatus for laser drilling vias in electronic assemblies that is capable of forming vias with high taper, while maintaining acceptable system throughput, accuracy and overall quality.
SUMMARY OF THE DISCLOSURE
[0008] An object of the present disclosure is, therefore, to provide a method and an apparatus in the form of a laser processing system with improved ability to micromachine high taper vias in workpieces comprising electronic substrates.
[0009] In one embodiment, via taper and quality are controlled by adjusting laser pulse parameters to yield the desired result. In the case where a blind via is being drilled through organic material to reach a non-organic layer within the substrate, via drilling can be divided into two phases. In the first phase, organic material is removed from the via with as few pulses as possible while maintaining the desired top diameter of the via. In the second phase, remaining organic material from the bottom of the via is removed while maintaining the desired bottom diameter and without causing damage to the inorganic conductor at the bottom of the via. It is an object to determine a single set of laser pulse parameters that can effect drilling for both the first and second phases of this process and thereby achieve greater efficiency in the drilling process.
[0010] Laser pulse parameters that may be adjusted to achieve the effects noted above include pulse energy, pulse fluence, pulse duration, pulse repetition rate, number of pulses, pulse spot size, pulse temporal shape, pulse spatial distribution, and wavelength. An object is to provide a method and an apparatus to select a single set of laser pulse parameters that can be used for both phases of drilling for a single via. By using a single set of parameters, the control architecture of the system can be simplified because it does not have to alter parameters on the fly during drilling. Drilling efficiency is also potentially increased, in instances where parameters take longer than the inter-pulse interval of the laser, which would require that some pulses be discarded rather than being used to machine the workpiece.
[0011] The angle of the side wall is an important determinant of via quality. Assuming that the side wall is of the desired straight topology, side wall angle or taper is measured as the ratio of the diameter of the bottom of the hole to the diameter of the top of the hole, expressed as a percentage. FIG. 2 shows a via 30 with a taper of about 75%, where the exposed conductor at the bottom of the via 30 has a diameter that is approximately 75% of the diameter of top of the via. FIG. 2 shows a via having a plating 36 that electrically connects conductor 10 to conductor 12 . One reason taper is important is that low taper makes the plated via more susceptible to thermal stress caused by the differences in coefficients of thermal expansion between the various materials used. Vias with low taper exhibit cracking and delamination of plating at a much greater rate than vias with high taper. Side walls should be straight and not exhibit taper where the bottom of the hole has a larger diameter than the top. Another determinant of blind via quality is the presence or preferably absence of a “foot” of organic material at the bottom of the hole where the side wall meets the bottom conductor. The absence of a foot is important because one of the determinants of the quality of the plating is related to the area of conductor plated at the via bottom.
[0012] Via drilling can be accomplished by irradiating the surface of the substrate with one or more laser pulses having predetermined pulse parameters directed to substantially the same location on the substrate. The diameter of the laser pulse is on the order of the size of the via to be drilled. Each of the one or more pulses removes material from the hole until the desired layer is reached. At this point, if it is determined that there exists organic material at the bottom of the via to be removed, one or more laser pulses with the same set of predetermined pulse parameters will be directed at the same location to clean the remaining organic material from the bottom of the via while maintaining the desired bottom diameter of the hole.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a cross-sectional view of a multilayer workpiece.
[0014] FIG. 2 is a schematic diagram showing a plated via in the workpiece of FIG. 1 .
[0015] FIG. 3 is a graph of a CO 2 laser pulse with a Gaussian temporal distribution.
[0016] FIG. 4 is a graph showing material removal during via drilling.
[0017] FIG. 5 is a graph showing the relationship between laser pulse energy and via top diameter for pulses with Gaussian spatial distribution.
[0018] FIG. 6 is a graph showing the relationship between laser pulse energy and via top diameter for pulses with “top hat” spatial distribution.
[0019] FIG. 7 is a graph showing the relationship between laser pulse energy and via bottom diameter.
[0020] FIG. 8 is a diagram showing a via drilled in accordance with the methods described herein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] A preferred CO 2 processing laser is a pulsed CO 2 laser operating at a wavelength of between about 9 μm and about 11 μm. An exemplary commercially available pulsed CO 2 laser is the Model Q600 Q-switched laser (9.3 μm) manufactured by Coherent-DEOS of Bloomfield, Conn. Because CO 2 lasers are unable to effectively drill vias through metal layers 12 and 14 , multilayer workpieces 10 drilled with CO 2 processing lasers either lack metal layers 12 and 14 or are prepared such that a target location has been pre-drilled with a UV laser or pre-etched using another process such as, for example, chemical etching, to expose dielectric layers 20 .
[0022] CO 2 Q-switched lasers exhibit a temporal profile that is typically described as “Gaussian,” although examination of FIG. 3 shows that the essentially Gaussian pulse is modified by the “tail,” which represents energy leakage from the laser cavity as the lasing activity falls off. Research by the applicants indicates that this pulse shape may be effectively used to drill high taper vias in multilayer material. Gaussian temporal distribution is distinguished from Gaussian spatial distribution, which is a function of the laser pulse cross-section. The laser pulses discussed herein have both Gaussian temporal and spatial distributions. Other solid-state lasants or CO 2 lasers operating at different wavelengths may be used in the disclosed laser apparatus. Various types of laser cavity arrangements, harmonic generation of the solid state laser, Q-switch operation for the solid-state laser and the CO 2 laser, pumping schemes, and pulse generation methods for the CO 2 laser are also contemplated. For cases in which non-Q-switched lasers are used, additional pulse shaping optics may be used to form shorter pulses from longer pulses, up to and including lasers operating in continuous wave (CW) mode.
[0023] FIG. 4 shows a graph of material removal during the via drilling process. The X-axis represents ablation depth and the Y-axis represents number of pulses. As shown in FIG. 4 , pulses 0 to N 0 remove bulk material from the via, reaching the underlying inorganic conductor at pulse N 0 . Optional δN pulses then are used to clean the remaining organic material from the bottom of the via. N 0 can typically range from 1 to several tens or hundreds of pulses, depending upon the pulse parameters such as fluence and wavelength and amount of material to be removed. δN can typically range from 0 to several tens or hundreds of pulses, again depending upon the pulse parameters and amount of material to be removed.
[0024] For CO 2 laser interaction with organic polymers, material removal is realized mainly through laser induced thermal degradation, which can occur before reaching the vaporization point. It is possible that some vaporization can occur through the phase transitions (solid-glassy state-melt-vapor). Since for CO 2 laser irradiation, the absorption depth of polymer is about 10 μm, which indicates that the laser beam can penetrate into polymers to substantial depths as to cause volumetric heating rather than surface heating only.
[0025] Current drilling practice has shown that a single laser pulse can remove explosively the whole layer of ABF resin of around 35 μm in thickness on copper pad. However, to achieve a good via shape, it is preferred to remove the bulk resin material by a group of short pulses, with each pulse removing only a fraction of total depth of material gently rather than explosively, which gives better control over the volumetric heating process.
[0026] To a first-order approximation, the ablation rate per pulse (χ) for a Gaussian CO 2 laser pulse to ablate polymer through thermal decomposition can be expressed as:
[0000]
χ
=
k
0
·
F
·
1
+
k
1
I
(
1
)
[0000] where k 0 and k 1 are coefficients related to material constants, F is fluence, I is peak power intensity. For a given peak power intensity I, the ablation depth per pulse χ is controlled by the fluence, F. Fluence can be approximated by multiplying peak power intensity I by pulse width τ:
[0000] D t ≈F=I·τ (2)
[0027] Fluence is a principal determinant of via top diameter. As fluence increases, material removal becomes more explosive and less controlled, particularly for Gaussian temporal pulses. FIG. 5 shows a cross-sectional view of the spatial distribution of fluence of a laser pulse with essentially Gaussian spatial beam distribution. For a given material, the size of the hole is related to the per-pulse fluence. Applicants' experimental results show that, for a given spot size, there is a small range of fluence values that will yield a desired via top diameter. This is illustrated in FIG. 5 , where D 1 and D 2 are the via top diameters drilled with two different pulse fluences. As can be seen, for fluence F 1 , the pulse energy exceeds the dielectric ablation threshold for a diameter D 1 , whereas the pulse with fluence F 2 exceeds the dielectric threshold for a diameter D 2 , thereby drilling a hole with that top diameter.
[0028] This principle applies to beam spatial distributions other than the Gaussian distribution. Laser pulses with “top hat” distributions can be used to drill vias as described in U.S. Pat. Nos. 6,433,301 and 6,791,060 of Dunsky et al., each of which is incorporated herein by reference. FIG. 6 shows a cross-sectional view of pulses with top hat spatial distributions. As shown in FIG. 6 , laser pulses with top hat spatial distributions exhibit a relationship between fluence, ablation and via top diameter similar to that of the Gaussian spatial distribution.
[0029] Another principle of via drilling relates to the size and quality of the bottom of the via. In contrast to the via top diameter, the bottom diameter is not simply a function of the fluence. Complicating the drilling is the existence of the non-organic layer that forms the bottom of the via. This non-organic layer is typically comprised of copper, but could include other conductive material. This layer can alter the via drilling process in several ways: First, the non-organic layer tends to reflect the laser energy rather than absorb it, as does the organic material. This reflected energy can cause unwanted erosion of the organic layers resulting in undercutting of the organic layers, which makes the taper negative, an unwanted result. The organic conductor also acts as a heat sink, conducting heat away from the via as it is being drilled. This cooling of the bottom of the via encourages vaporized organic material to re-deposit on the bottom, thereby preventing the subsequent plating from making complete electrical contact with the conductive material at the bottom of the contact. Also, the non-organic layer can be partly melted by the laser pulses used to drill the via, causing the bottom of the via to assume a smooth, glassy appearance, in contrast to the typical nodular or rough appearance. This smoothness makes it more difficult for the subsequent plating to attach to the bottom of the via and can prevent good electrical contact. All of these effects are related to the bottom diameter, either directly or indirectly.
[0030] It is important then, to apply the correct amount of power when the laser pulses reach the intended bottom of the via in order to achieve the correct diameter without causing ill effects. Applicants' research indicates that the bottom diameter of the via is a function of the following equation:
[0000] D b ≈F/τ 1/2 , (3)
[0000] which shows that D b , the diameter of the bottom of the via, is proportional to the fluence F, divided by the square root of the pulse width, τ. FIG. 7 shows the relationship between the diameter of the bottom of the via, damage to the bottom of the via and the fluence divided by the square root of the pulse width. As can be seen from FIG. 7 , the fluence and pulse width must be adjusted to be able to achieve the desired bottom diameter while avoiding damage to the pad, or bottom of the via.
[0031] A solution to the problem of laser drilling a via with desired top and bottom diameters while avoiding damage to the bottom of the via can be arrived at by simultaneously solving equations (1) and (3) with the additional constraint given by:
[0000] D b =( T ) D t 1 (4)
[0000] where D b and D t are the desired bottom and top diameters and T is the taper, expressed as a fraction between −1 and +1. Since the fluence is a function of both pulse width and peak power intensity, there exists more than one solution to the above equations. In fact, a range of pulse widths and peak power intensities exist that will solve the problem. Within this solution space, a particular pulse width and peak power will be selected that tends to minimize the amount of time spent drilling, i.e., minimizes the number of pulses required to drill the via, and is consistent with the capabilities of the laser and optics selected.
[0032] FIG. 8 shows a via drilled in a multilayer substrate using laser pulses calculated by the above methods. The substrate organic material is ABF GX3 (Anjinomoto Co. Ltd., Tokyo, Japan) with a copper non-organic pad at the bottom of the via. The drilled via has a top diameter of 53 microns and a taper of 80%. The via was drilled with a CW Q-switched 2.4 W peak power intensity CO 2 laser model Q-600 referenced above, operating at a pulse repetition rate of 30 KHz. Five pulses were required to drill the via as shown. As can be seen in FIG. 8 , the via is free from debris, and the bottom of the via exhibits a texture that indicates it has not been melted or otherwise damaged.
[0033] It will be apparent to those of ordinary skill in the art that many changes may be made to the details of the above-described embodiments of this invention without departing from the underlying principles thereof. The scope of the present invention should, therefore, be determined only by the following claims.
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A method of and an apparatus for drilling blind vias with selectable tapers in multilayer electronic circuits permit forming electrical connections between layers while maintaining quality and throughput. The method relies on recognizing that the top diameter of the via and the bottom diameter of the via, which define the taper, are functions of two separate sets of equations. Simultaneous solution of these equations yields a solution space that enables optimization of throughput while maintaining selected taper and quality using temporally unmodified Q-switched CO 2 laser pulses with identical pulse parameters. Real time pulse tailoring is not required; therefore, system complexity and cost may be reduced.
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BACKGROUND OF THE INVENTION
DSA (Digital Subtraction Angiography) and other angiographic tests based on computer images are being used for diagnosis of vascular and tumorous diseases. In such angiographic tests, in inserting a catheter from a puncture hole in a blood vessel into a target artery, the front end of the catheter must be freely moved in the direction of travel and along curves by applying an external force on the hand side in a remote control fashion.
In recent years, it has been required to perform not only a selective operation for inserting a catheter into a primary branch of the aorta but also a super-selective operation for inserting a catheter into secondary and tertiary branches of said primary branch. Thus, a higher technique and rich experience have become indispensable for said remote control.
To secure the remote controllability (torque controllability), it has been common practice to resort to selection of a material for catheters.
That is, if such material of a catheter is soft (highly flexible), it is difficult to effect remote control on the hand side. Thus, as suggested by Japanese Utility Model Application Laid-Open Specification No. 500013/1985 (International Application PCT/US 83-864) and Japanese Patent Application Laid-Open No. 218966/1983, excluding a predetermined short region on the front end side where softness is required in view of stability of a catheter, the entire portion on the hand side is reinforced by steel wire mesh or is constructed in the form of a double tube made of materials having different entire portion on the hand side is rigid with reduced flexibility, thereby giving torque controllability to the catheter.
Making catheters slender is an adverse factor for said torque controllability, making it difficult to secure safety for remote control. For this reason, there has not been established an operating method for inserting a catheter through a puncture hole in the brachial artery, which is thin and long, for angiographic tests; at present, angiographic tests with respect to the general artery are conducted by inserting a catheter through a puncture hole in the femoral artery, which is thick.
However, it may be said that said controllability for catheters with respect to blood vessels can be secured by simultaneously using a catheter introducing guide wire which is highly flexible and which will not form a fixed bend (a so-called bending habit) even if subjected to an operating external force, said guide wire being inserted into a catheter and operated for piloting the catheter. In other words, unlike the technique resorting to the selection of a material for catheters, this idea is to look to a guide wire for torque controllability and, as it were, to reflect the controllability of the guide wire on the catheter.
In the case where such special technique is adopted, if the entire portion on the hand side is made rigid as by double-tube construction or steel wire mesh, this arrangement will destroy the superior flexibility that the guide wire possesses.
That is, in inserting a catheter into a puncture hole in the brachial artery, since, anatomically, the region extending from the sub-clavian artery via the aortic arch to the downwardly extending artery is sharply bent at less than 90 degrees, the catheter, even if made rigid, will form a corresponding bending habit under the action of body heat.
Further, in inserting a catheter into a puncture hole in the femoral artery, if this artery is abnormally bent or deformed owing to severe arteriosclerosis, the catheter inserted therein is heated by body heat and forms a bending habit corresponding to such abnormal bend.
As a result, the guide wire expected to guide the catheter correctly is "defeated" by the catheter and its inherent torque controllability is impaired, so that the catheter cannot be correctly operated until it reaches the target artery. Further, the more rigid the catheter material, the more strongly the catheter is urged against the blood vessel wall when it is retained in the blood vessel. As a result, the danger of formation of a thrombus or occlusion of blood vessel taking place increases.
In brief, when it is desired to utilize the torque controllability of a guide wire to be used for remote-controlling a catheter, it is preferable that the main portion of the catheter be made soft with high flexibility, since this makes it possible to precisely reflect the free movement of the catheter introducing guide wire; thus, the performance of the guide wire can be efficiently and reasonably developed.
On the other hand, a catheter is a medical instrument for injecting a contrast agent into a target artery. If, however, its front end portion is made soft with high flexibility, as in the known example described above, the front end portion of the catheter is subjected to the pressure under which the contrast agent is injected, swinging to and fro, with the result that the control agent cannot be injected into the target artery correctly and without loss and concentratedly. In this connection, even if a superior DSA apparatus by which target locations can be graphically represented with diagnostic contrast agent, there would be the danger of said contrast agent being misdirected.
In the case where it is desired to effect plastic working to provide an intrinsic bend suitable for the primary, secondary and tertiary branches of the artery so as to provide the front end portion of the catheter with the pilot function for inserting the catheter into a blood vessel, the softer the front end portion, the more difficult it is to form such bend in a stable manner.
Thus, so long as the above-described technique of inserting and operating a catheter to be used simultaneously with a guide wire is adopted, it is preferable that the front end portion of the catheter have the necessary minimum of rigidity (low flexibility). It goes without saying that the necessary minimum means a degree which does not hurt the blood vessel wall nor impair the torque controllability of the guide wire. It appears that a catheter for angiography meeting the necessary conditions described above has not been developed yet.
SUMMARY OF THE INVENTION
The present invention has for its object the provision of a catheter for angiography which meets such demand.
Thus, a first object of the invention is to provide an arrangement wherein while a catheter as a whole possesses a degree of flexibility which allows the catheter to follow the bending of an introducing guide wire, the main portion thereof in the region to be introduced into a blood vessel is made softer with high flexibility than its front end portion which is shorter than said main portion, whereby the movement of the guide wire is precisely reflected so that the catheter efficiently follows the movement thereof, with the torque controllability of the guide wire being developed to a maximum, and there is no danger that when the catheter changes direction or stays in a blood vessel, it forms a bending habit, not impeding the blood flow though it contacts the blood vessel wall, thus contributing to prevention of formation of a thrombus.
A second object is to provide an arrangement wherein the front end portion in the remaining region to be introduced into a blood vessel is made rigid with low flexibility, so that the front end portion of the catheter is hardly subjected to the reaction force due to spouting of a contrast agent and while maintaining a stable attitude, the catheter enables the contrast agent to be injected into a target artery correctly and without loss and concentratedly, and wherein in the case where an intrinsic bend suitable for various branches of the aorta is to be formed so as to provide the front end portion of bend can be made stably and plastically deformed.
A third object of the invention is to provide an arrangement wherein the main portion of the catheter is made soft with high flexibility and the controllability of a guide wire for introducing the same is utilized, thereby making it possible to make the catheter itself slender and hence selective and super-selective operation of catheter in connection with the trans-brachial artery (which is thin) catheterization technique.
Other objects of the present invention, together with the concrete construction of the invention, will become more apparent from the following description of preferred embodiments.
BRIEF DESCRIPTION OF THE INVENTION
FIG. 1 is an external view, partly cut away, of a catheter for angiography according to the present invention;
FIG. 2 is an external view, also partly cut away, of a catheter introducing guide wire to be simultaneously used with the catheter;
FIG. 3 is a fragmentary enlarged sectional view;
FIG. 4 is a fragmentary developed enlarged sectional view;
FIGS. 5 through 7 are sectional views showing various modifications of catheters corresponding to FIG. 4; and
FIG. 8 (I), (II) and (III) are sectional views showing the steps of insertion of a catheter into a blood vessel.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In an external view shown in FIG. 1, a catheter for angiography according to the invention is collectively indicated by the numeral 10 and it is made from a synthetic resin having suitable degrees of bursting strength and flexibility, such as polyamide elastomer, polyurethane elastomer, polyester elastomer or polyethylene, into a tube form, the proximal end portion thereof on the hand side having an on-off valve 12 for contrast agent injection connected thereto through a hub or connector 11.
The numeral 13 in FIG. 2 collectively indicates a catheter introducing guide wire to be used simultaneously with the catheter 10. As suggested from a fragmentary enlarged sectional view in FIG. 3, the guide wire comprises a metal core wire 14 and a covering wire 15 densely wound in coil form around the outer peripheral surface thereof, and is longer than the catheter 10. Even if an operating external force for forward or rotational movement is applied to the guide wire 10 from the hand side thereof, the guide wire 10 will not form a bend (or so-called bending habit), so that its torque controllability can be transmitted to the catheter 10.
In the front end portion 13b of the guide wire 13, said core wire 14 is made gradually thin from the main portion 13a, whereby it is made soft to have the same or higher degree of flexibility than the catheter 10; thus, when it is inserted into a blood vessel, it will not hurt the blood vessel wall.
Since the overall length of the catheter 10 varies in connection with a target artery, it cannot be made constant; however, if the entire region of the catheter 10 to be inserted into a blood vessel has a fixed length comprises the catheter main portion 10a having a fixed length l1 and being made soft to have a high degree of flexibility, and the catheter front end portion 10b having a less length l2 and being made rigid to the necessary minimum degree to have a low degree of flexibility.
The necessary minimum degree means that when the catheter is inserted into a blood vessel, there is no danger of hurting the blood vessel wall and that the torque controllability of the catheter introducing guide wire used simultaneously with the catheter can be satisfactorily transmitted. That is, although the main portion 10a of the catheter 10 differs in flexibility from the front end portion 10b, the region L to be inserted into a blood vessel has a certain degree of flexibility required to follow the free bending of the guide wire 13.
As to the concrete arrangement of the catheter 10 for obtaining such change in flexibility, various forms shown in FIGS. 4 through 7 may be freely adopted.
FIG. 4 is a fragmentary developed view of FIG. 1. In this figure, the main portion 10a of a synthetic resin tube 16 forming the whole of the catheter 10 is reduced in wall thickness, whereas the remaining front end portion 10b of the synthetic resin tube 16 is increased in wall thickness. The catheter 10 of such construction, which uses a common synthetic resin tube 16 for the main portion 10a and front end portion 10b, can be mass produced by inserting a core (not shown) in the form of a tapered conical bar into the hollow region thereof and, after molding, withdrawing said core.
As is clear from FIG. 5 showing a first modification corresponding to FIG. 4, the wall thickness of a synthetic resin tube 17 forming a catheter 10 is uniform, but the outer diameter of the main portion 20a is small, while the front end portion 20b is large. The greater the outer diameter, the greater the bending rigidity of the catheter 10, and hence its flexibility can be made low. And the catheter 10 of such construction can be easily formed of a synthetic resin tube 17 common to the main portion 20a and front end portion 20b by using a core (not shown) in the form of a reversely tapered conical bar.
FIG. 6 shows a second modification corresponding to FIG. 4, wherein the front end portion 30b of a synthetic resin tube 18 forming a catheter 30 is integrated with a separate reinforcing tube 19 of flexible synthetic resin material in two layers, so that it is rigid with low flexibility as compared with the remaining single-layer main portion 30a in the form of a synthetic resin tube 18. Such reinforcing tube 19 can be satisfactorily integrated with the inner wall surface of the synthetic resin tube 18 forming the outer layer by heat seal or other fixing means.
FIG. 7 shows a third modification corresponding to FIG. 4, wherein only the front end portion 40b of a synthetic resin tube 21 forming a catheter 40 is integrally lined with a separate reinforcing tube 23 of flexible synthetic resin integrally covered with non-metallic mesh 22. As a result, the front end portion 40b is made rigid, having lower flexibility than the main portion 40a. Such catheter 40 can also be easily produced by covering the outer peripheral surface successively with said mesh 22 and synthetic resin tube 21.
At any rate, since the catheter 10 in the present invention has its main portion 10a made more flexible and softer than the front end portion 10b, the catheter 10 smoothly and efficiently follows the piloting bending movement of the guide wire used simultaneously therewith and the torque controllability that the guide wire 13 possesses can be precisely reflected on the catheter 10. And there is no danger of the catheter forming a fixed bend (bending habit) when it changes its direction in a blood vessel or is retained therein; although it contacts the blood vessel wall, it does not impede the blood flow and contributes much to prevention of formation of a thrombus.
In this connection, in FIG. 1 which is a schematic view, the boundary position P between the main portion 10a and the front end portion 10b of the catheter 10 has been shown as an easily distinguishable definite demarcation line; however, as is suggested from the arrangements shown in FIGS. 4 through 7, concerning the outer diameter, inner diameter, wall thickness and the degree of flexibility of the catheter 10, it is preferable that the main portion 10a and the front end they obscurely steplessly and smoothly change to each other across the boundary position P. The reason is that with this arrangement, the above function and effect can be further improved and that the main portion 10a and the front end portion 10b of the catheter 10 can be fabricated in such a manner that they are hardly separable from each other.
On the other hand, since the front end portion 10b is made rigid by being made less flexible than the main portion 10a, it is hardly subjected to the reactive force from a contrast agent, thus making it possible to inject the contrast agent into a target artery without loss and accurately while maintaining a stable attitude resisting the spout pressure.
Further, to provide the pilot function for insertion into a target location such as a primary branch of the aorta or a sub-branch thereof, the front end 10b of the catheter 10 can be plastically deformed very easily in advance into any form as an intrinsic bend (bending habit) conforming to the target artery, and such various bent forms can be stably held.
Concerning the bent form of the front end portion 10b of the catheter 10, in FIG. 1, it is plastically deformed into an arc having a relatively large curvature radius dimension R1 which allows it to contact the inner wall of the aorta, and a shape restoring force. Thereby, it functions as a pilot for inserting the arcuate front end portion 10b into a primary branch of the aorta.
Concerning the guide wire 13 to be used simultaneously therewith, the front end portion 13b is plastically deformed into an arcuate form, as shown in FIG. 2, which has a smaller curvature radius dimension R2 than the arcuate front end portion 10b of the catheter 10 and which has a shape restoring force, thereby enabling the arcuate front end portion 13b of the guide wire 13 to function as a pilot for insertion into a secondary or tertiary branch of the aorta.
According to this, the catheter 10 is used simultaneously with the guide wire 13 and the required torque controllability is obtained from the guide wire, while the pilot function for insertion into a primary branch of the aorta is imparted to the relatively large arcuate front end portion 10b of the catheter 10 and the pilot function for insertion into secondary and tertiary branches is imparted to the relatively small arcuate front end portion 13b of the guide wire 13. As a result, there is no need to provide various intrinsic bent shapes to the front end portion 10b of the catheter 10. Furthermore, selective and super-selective catheter operation can be effected in connection with the trans-brachial artery catheterization technique while making versatile use of the catheter 10 having the relatively large arcuate front end portion 10b capable of contacting the inner wall of the aorta.
That is, FIG. 8 (I), (II) and (III) are schematic views wherein the catheter 10 described above is used for an graphic test of the renal artery B, which is a primary branch of the aorta A. In use, as shown in (I), under the pilot action of said guide wire 13, the catheter 10 is inserted into a descending artery A through a puncture hole (not shown) in the brachial artery, whereupon the front end portion 13b of the guide wire 13 is once retracted from the front end portion 10b of the catheter 10.
Then, the front end portion 10b of the catheter 10 is advanced along and in contact with the inner wall of the aorta A while retaining its arcuate bent form, until it is directed to the branch base of the renal artery B. In this case, anatomically, the branches of the descending artery A have angles of not more than 90 degrees as downward from the aorta A. Thus, according to the trans-brachial catheterization technique, the arcuate front end portion 10b of said catheter 10 can be correctly directed into a primary branch of the aorta A.
Then, as shown in FIG. 8 (II), the catheter 10 is fed by the guide wire 13, whereby the front end portion 10b of the catheter 10 advances deep into the renal artery B. Therefore, as soon as it reaches the target location, the guide wire 13 is extracted and then a contrast agent will be injected through the catheter 10 from the hand side thereof, as shown in FIG. 8 (III). Since the front end portion 10b of the catheter 10 is made more rigid with low flexibility than the main portion 10a, there is no danger of the front end portion being swung to and fro as if dancing under the pouring pressure of the contrast agent, as described above.
The above description relates to an operating method for inserting the catheter 10 into a primary branch of the aorta A. When it is desired to insert the catheter 10 into a secondary or tertiary branch of a primary branch, this can be attained, though not shown, by advancing the guide wire 13 alone from the state of Fig. (II) relative to the catheter 10, thereby exposing the front end portion 13b of the guide wire 13 from the front end portion 10b of the catheter 10.
Then, the front end portion 13b of the guide wire 13 maintains said small arcuate bent form by its own shape restoring force, thus performing the versatile pilot function of insertion into a secondary or tertiary branch; thus, under the guiding action thereof, the catheter 10 can be advanced deep into a secondary or tertiary branch. Thereafter, the guide wire 13 alone is extracted, leaving the catheter 10, through which a contrast agent is then injected, of course.
At any rate, since the main portion 10a of the catheter 10 is made soft with high flexibility, the catheter precisely follows the movement of the guide wire 13 when it is inserted over a long distance into a secondary or tertiary branch as well as when it is inserted into a primary branch of the aorta A. Therefore, the longer the distance, the more remarkably its function and effect will be developed.
When the catheter 10 is used in connection with the trans-brachial catheterization technique, it has to be longer and thinner than when it is used in connection with the trans-femoral catheterization technique. Thus, if the catheter 10 which is used simultaneously with the guide wire 13 as described above is adopted, the selective and super-selective catheter operation in connection with the trans-femoral artery (which is thin and long) catheterization technique can be performed safely and reliably by anyone without relying on high technique or much experience.
If a trans-brachial artery catheterization technique is established on the basis of the present invention, this means that angiographic tests which have heretofore been difficult for outdoor patients can be conducted, contributing much to early diagnosis of vascular and tumorous diseases and to injection of an anticancer agent into a target organ. Thus, the invention can be said to be very useful. In addition, it goes without saying that the present invention is also applicable to angiographic tests based on the conventional trans-femoral artery catheterization technique.
While the invention has been particularly shown and described in reference to preferred embodiments thereof, it will be understood by those skilled in the art that changes in form and details may be made therein without departing from the spirit and scope of the invention.
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The present invention relates to a catheter for angiography adapted to be used simultaneously with a catheter introducing guide wire and advanced into a blood vessel under the pilot action of the guide wire, and is characterized in that in order to secure smooth and reliable remote controllability (i.e., torque controllability) from the hand side, a high degree of flexibility precisely reflecting the movement of the guide wire and an injecting function for accurately directing a contrast agent into a target artery, the catheter is designed so that, although the catheter has, as a whole, a degree of flexiblity to enable it to follow the movement of the guide wire, its main portion in the region to be introduced into a blood vessel has a higher degree of flexibility than that of its front end portion which is shorter than the main portion.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is the National Stage of International Patent Application No. PCT/US2013/029159, filed on Mar. 5, 2013, which claims priority to and all advantages of U.S. Provisional Patent Application No. 61/667,717 filed Jul. 3, 2012, the content of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The present application relates generally to a method of manufacturing impeller and turbine assemblies. More specifically, the present application relates to forming joints between various elements of impeller and turbine assemblies without the use of brazing.
BACKGROUND
Various components of transmission assemblies such as, for example, impeller assemblies and turbine assemblies are subject to significant forces from transmission fluid flowing throughout transmission housing. The impeller assembly includes a plurality of impeller blades affixed to an impeller assembly. The blades extend radially and are circumferentially spaced around the entire housing. Adequate mechanical attachment of the impeller blades to the impeller assembly has not been achieved. Therefore, the impeller blades have been attached to the impeller assembly by way of a coating process known as brazing. Likewise, the turbine blades have also been attached to the turbine housing by brazing in a similar manner.
Brazing is achieved by applying alloys to the joints formed between the blades and the housing and raising the temperature of the assembly to the melting temperature of the alloy. Additionally, brazing is also known to cause a rough surface resulting in oil turbulence in the impeller and turbine assemblies, which adversely affects efficiency and performance. While the brazing process has generally proven acceptable to secure the blades to the housings, a number of drawbacks make it desirable to eliminate brazing by way of a more secure mechanical attachment.
For example, the alloy used to braze the joints described above cause significant environmental hazards requiring significant measures be taken to avoid a detriment to technician health and contamination to the environment at large. Furthermore, the temperatures at which the assemblies must be raised to melt the brazing material is known to significantly weaken the metallic structure of both the housing and the blades. Furthermore, the addition of brazing material to the assemblies increases the mass of these assemblies significantly, which reduces the efficiency of the transmission and the associated vehicle.
Therefore, it would be desirable to eliminate the addition of brazing material to the impeller and turbine assemblies of a transmission by way of providing a more secure mechanical attachment of these blades to their housing.
SUMMARY
A method of manufacturing an impeller and turbine housing of a transmission includes providing an impeller housing and a turbine housing. An impeller blade is provided defining an impeller receptor and a turbine blade is provided defining a turbine receptor. The impeller blade is mated to the impeller housing by deforming a portion of the impeller housing into the impeller receptor. The turbine blade is mated to the turbine housing by deforming a portion of the turbine housing into the turbine receptor. By way of deformation of the housings, the impeller blade is secured to the impeller housing and the turbine blade is secured to the turbine housing in a mechanically sound manner.
By forming a receptor into the impeller blade and the turbine blade, a deformation of the housing into the receptor provides an interlocking joint between the housing and the blades. By securely interlocking the blade and the housing, a mechanical attachment is achieved providing adequate strength to the joint between the housing and the blades to withstand the forces known to occur in a transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 shows a partial sectional view of a transmission;
FIG. 2 shows a partial cross-sectional view of an impeller assembly of the present invention;
FIG. 3 shows a plan view of the impeller assembly along lines 3 - 3 of FIG. 2 ;
FIG. 4 shows an exploded view of the impeller assembly of the present invention;
FIG. 5 shows an exploded view of an impeller blade and an impeller shroud of the present invention;
FIG. 6 shows a cross-sectional view of the exploded impeller assembly along lines 6 - 6 of FIG. 4 ;
FIG. 7 shows a partial cross-sectional view of the impeller blade assembled to the impeller assembly and impeller shroud prior to deformation;
FIG. 8 shows the deformation step of the impeller assembly and the impeller blade;
FIG. 9 shows an exploded view of the turbine assembly of the present invention;
FIG. 10 shows a flange of the turbine assembly;
FIG. 11 shows an exploded, cross-sectional view of the turbine assembly;
FIG. 12 shows the turbine blade assembled to the turbine assembly and turbine shroud prior to deformation; and
FIG. 13 shows a partial cross-sectional view of the joints of the turbine assembly after deformation.
DETAILED DESCRIPTION
Referring to FIG. 1 , a partial cross-sectional view of a transmission assembly is generally shown at 10 . Although this view is of an automotive transmission, it should be understood to those of ordinary skill in the art that this is just an exemplary view and that the scope of this application is beyond automotive. An impeller assembly 12 is shown fixed to a torque converter cover 14 in a known manner. A turbine assembly 16 is shown in an opposing relationship to the impeller assembly 12 as is known to those of skill in the art.
By way of establishing an environmental orientation of the impeller assembly 12 and the turbine assembly 16 , a stator 18 is positioned between the impeller assembly 12 and the turbine assembly 16 in a known manner. The stator 18 is in running engagement with a one-way clutch 20 of the transmission assembly 10 , also in a known manner.
The impeller assembly 12 includes an impeller housing 22 as shown here with an impeller blade 24 being mechanically attached as will be explained further herein below. The impeller blade 24 is positioned between the impeller housing 22 and an impeller shroud 26 .
The turbine assembly 16 includes a turbine housing 28 as shown here with a turbine blade 30 affixedly attached. The turbine blade 30 is positioned between the turbine housing 28 and a turbine shroud 32 . As set forth above, the turbine assembly 16 interacts with the impeller assembly 12 and the transmission assembly 10 in a known manner. It should be understood to those of ordinary skill in the art that the inventive feature disclosed in the present application can be used to eliminate brazing when used to affix blades to housing in any type of torque converting assembly.
As best represented in FIGS. 2-4 , the impeller blade 24 defines an impeller tab 34 that mates to a impeller groove 36 defined by the impeller housing 22 . As best represented in FIG. 3 , a plurality of impeller grooves 36 extend radially outwardly between a central opening 38 defined by the impeller housing 22 and a distal impeller rim 40 of the impeller housing 22 . As best shown in FIG. 4 , the impeller housing 22 defines an arcuate wall 42 into which the impeller groove 36 is defined. The impeller groove 36 extends substantially radially outwardly along the arcuate wall 42 defined by the impeller housing 22 .
The impeller tab 34 of the impeller blade 24 takes an arcuate shape and has a similar radius as the impeller groove 36 defined by the arcuate wall 42 so that a substantial portion of the impeller tab 34 contacts a base 44 of the impeller groove 36 when assembled, as best shown in FIG. 2 . A receptor 46 is defined by the impeller tab 34 . The receptor 46 is shown as a plurality of apertures 48 shaped as a series of spaced slots extending substantially along the impeller tab 34 .
A shroud tab 50 is spaced radially inwardly of the impeller tab 34 on the impeller blade 24 . The shroud tab 50 is received through a shroud slot 52 defined in an arcuate wall 54 of the impeller shroud 26 . The shroud tab 50 of the impeller blade 24 includes a circumferential length that is substantially the same as the circumferential length of the shroud slot 52 .
FIGS. 5-7 show the impeller blade 24 being moved into engagement with the impeller housing 22 and the impeller shroud 26 . The impeller tab 34 is received into the impeller groove 36 so that a distal end of the impeller tab 34 is positioned in an abutting relationship with the groove base 44 . The receptor 46 defined by the impeller tab 34 is substantially perceived into the impeller groove 34 . The shroud tab 50 defined by the impeller blade 24 is received through the shroud slot 52 so that a distal end of the shroud tab 50 extends beyond the arcuate wall 54 of the impeller shroud 26 as best represented in FIG. 7 .
Referring now to FIG. 8 , the method by which the impeller blade 24 is fixedly attached to the impeller housing 22 and impeller shroud 26 will now be explained. A staking tool 56 deforms a portion of the impeller housing 22 adjacent the impeller groove 36 so that material from the impeller housing 22 is forced into the receptor 46 defined in the impeller tab 34 of the impeller blade 24 . Therefore, the impeller housing 22 is placed in locking engagement with the impeller blade 24 securely affixing the impeller blade 24 to the impeller housing 22 . Because the receptors 46 are defined as a plurality of slots 48 , that portion of the impeller housing 22 appearing as a protuberance 58 enters the slots 48 in locking engagement.
Located radially inwardly from the impeller housing 22 , the shroud tab 50 of the impeller blade 30 that extend through the shroud slot 52 of the impeller shroud 26 is deformed into locking engagement with the impeller shroud 26 securely affixing the impeller shroud 26 to the impeller blade 24 . It is contemplated by the inventor that a rolling device or equivalent is used to deform the shroud tab 50 into locking engagement with the impeller shroud 26 .
Referring now to FIG. 9 , the method by which the turbine blade 30 is affixed to the turbine housing 28 and the turbine shroud 32 will now be explained. The turbine blade 30 defines a turbine tab 60 having a first member 62 and second member 64 . The turbine tab 60 is received into a turbine slot 66 defined by the turbine housing 28 . The first and second member 62 , 64 are received by corresponding first and second apertures 68 , 70 of the turbine slot 66 .
A shroud tab 50 is spaced radially inwardly on the turbine blade 30 from the turbine housing 28 and mates to a shroud slot 52 defined in the turbine shroud 32 in a manner substantially the same as that explained for the impeller shroud above. Therefore, further explanation of the shroud tab 50 defined by the turbine blade 30 and its mating engagement with the turbine shroud 32 is not included.
As best represented in FIG. 10 , a flange 72 is formed around a circumferential edge 74 of the turbine housing 28 to improve hoop strength of the turbine housing 28 . It is contemplated by the inventors that the improved hoop strength of the turbine housing 28 may enable decreasing the thickness of the turbine housing 28 further reducing overall mass of the turbine assembly 16 beyond the elimination of brazing.
FIGS. 11-13 show the method of securely engaging the turbine blade 30 to the turbine housing 28 and the turbine shroud 32 . A turbine receptor 76 is defined in the turbine blade 30 as a groove 78 . The groove 78 is spaced from a distal end of the tab 60 , the purpose of which will be evident further below. An offset 80 is defined in the turbine housing 28 so that an edge 82 of the turbine slot 66 is displaced from a plane defined by the turbine housing wall 84 .
As best shown in FIG. 12 , the tab 60 of the turbine blade 30 is inserted through the turbine slot 66 so that the receptor 76 defined by the turbine blade 30 is aligned with the plane defined by the turbine wall 84 . The offset 80 is forced in the direction of arrow 86 so that the edge 82 of the turbine slot 66 is forced into the receptor 76 defined by the impeller blade 30 , as best represented in FIG. 13 . The tab 60 is also deformed into locking engagement with the turbine housing 28 so that the turbine blade 30 is fixedly attached to the turbine housing 28 . It is believe that roll forming or cold forming the tab 60 into locking engagement with the turbine housing 28 will suffice. However, other methods of facilitating the locking engagement between the turbine blade 30 and the turbine housing 28 have also been contemplated by the inventor. It is believed that the manner in which the receptor 76 receives the offset 80 in combination with the deformation of the turbine tab 60 will create a substantially leakproof joint. In this manner, brazing is also reduced or eliminated from use with the turbine assembly 16 .
It is further contemplated by the inventor that additional securement may be required in high torque applications. Therefore, it is contemplated that an adhesive such as, for example, Loctite® or an equivalent may be used to satisfy high torque requirements.
While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation while material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention but that the invention will include all embodiments falling within the scope of the appended claims.
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A method of manufacturing an impeller and turbine assembly of a transmission includes providing an impeller housing and a turbine housing. An impeller blade defining an impeller receptor and a turbine blade defining a turbine receptor are provided. The impeller blade is mated to the impeller housing by deforming a portion of said impeller housing into the impeller receptor. The turbine blade is mated to the turbine housing by deforming a portion of the turbine housing into the turbine receptor. In this manner, the impeller blade is secured to the impeller housing and the turbine blade is secured to the turbine housing.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. provisional application No. 60/681,717, filed May 16, 2005, entitled MIXER AND PROCESS CONTROLLER FOR USE IN WASTEWATER TREATMENT PROCESSES.
BACKGROUND
[0002] Water is frequently used to transport unwanted materials—waste—to a facility where the waste is removed or neutralized in the water. For example, water carries most sewage and industrial waste, such as chemicals, in the form of wastewater to a treatment facility where the water is treated and then returned to the environment for future use. The wastewater treatment process typically includes three general phases. The first phase, or primary treatment, involves mechanically separating the dense solids in the wastewater from the less dense solids and liquid in the wastewater. This is typically done in sedimentation tanks with the help of gravity. The second phase, or secondary treatment, involves the biological conversion of carbonaceous and nutrient material in the wastewater to more environmentally friendly forms. This is typically done by promoting the consumption of the carbonaceous and nutrient material by bacteria and other types of beneficial organisms already present in the wastewater or mixed into the wastewater. The third phase, or tertiary treatment, involves removing the remaining pollutant material from the wastewater. This is typically done by filtration and/or the addition of chemicals and/or UV light and/or Ozone to neutralize harmful organisms and/or remove pollutant material.
[0003] The second phase of the wastewater treatment process typically includes an aerobic—with oxygen—portion in which bacterial and other microorganisms are provided dissolved oxygen to promote their consumption of the carbonaceous and nutrient materials, and an anoxic—oxygen from a nitrate/nitrite source—portion in which the bacteria and other microorganisms use the oxygen in the nitrate/nitrite for their metabolic functions. The second phase may also include an anaerobic—without oxygen—portion in which bacteria and other microorganisms metabolically function without oxygen. The aerobic, anoxic and anaerobic portions are typically carried out in tanks that are divided into aerobic, anoxic and anaerobic zones. The tank may include one zone in which the aerobic portion operates and one in which the anoxic portion operates and one in which the anaerobic portion operates, or the tank may include any combination of any number of these zones. In some applications, a tank may be solely dedicated to one of the three aerobic, anoxic and anaerobic portions.
[0004] In the aerobic process, wastewater that includes ammonium (NH4) and organic waste containing nitrogen, for example urea ((NH2)2CO), enters the aerobic zone. In the presence of dissolved oxygen (02), bacteria and other microorganisms convert the ammonium into nitrate (N03) via nitrite (N02). The nitrate can then be anoxically processed into nitrogen gas (N2), which is harmless in the environment. A blower and diffusers supply the dissolved oxygen to the wastewater. The blower provides air to the diffusers, and the diffusers generate and release tiny bubbles so that the oxygen in the bubbles will dissolve in the wastewater. As the aerobic process progresses, the amount of ammonium in the wastewater decreases while the amount of nitrate and dissolved oxygen increases. The amount of dissolved oxygen increases because the demand for the dissolved oxygen decreases as the amount of nitrate increases. After most of the ammonium has been converted into nitrate, the wastewater is ready to be anoxically processed.
[0005] In the anoxic process, wastewater that includes nitrate and the organic waste containing nitrogen enters the anoxic zone. In the absence of dissolved oxygen, bacteria and other microorganisms convert the nitrate into nitrogen gas and the organic waste containing nitrogen into ammonium. As the anoxic process progresses, the amount of nitrate decreases and the amount of ammonium increases. After most of the nitrate has been converted into nitrogen gas, the wastewater is ready to be aerobically processed or treated in the tertiary treatment phase.
[0006] Mixing the contents in each of the aerobic and anoxic zones promotes the conversion reactions in each zone by increasing the contact of the components, such as the dissolved oxygen (aerobic zone), nitrite/nitrate (anoxic zone), wastewater, and bacteria and other microorganisms, with the other components in each zone. In the aerobic zone, the wastewater is typically mixed by the movement of the tiny bubbles through the wastewater and a mechanical mixer that includes a screw or blade that is turned by a motor. In the anoxic zone, a mechanical mixer typically only mixes the wastewater because the anoxic process requires little or no dissolved oxygen, which is provided in the aerobic zone by the tiny bubbles from the diffusers.
[0007] During the aerobic process, the amount of dissolved oxygen and ammonium in the wastewater, along with the total suspended solids (TSS) of the wastewater, are monitored to determine whether the amount of dissolved oxygen injected into the wastewater needs to be increased or decreased, whether or not the wastewater is ready to be processed anoxically, and whether or not the wastewater should be mixed more aggressively. Similarly, during the anoxic process, the amount of nitrate and ammonium in the wastewater, and the TSS of the wastewater are monitored to determine whether or not the wastewater is ready to be processed aerobically or treated in the tertiary phase, and whether or not the wastewater should be mixed more aggressively. With this information, one then determines whether or not to inject more tiny bubbles into the wastewater to increase the amount of dissolved oxygen or to more aggressively mix the wastewater. If the amount of dissolved oxygen in the wastewater should be increased, then the operator turns up the blowers to the diffusers. If the wastewater should be more aggressively mixed, then the operator turns up the blower and/or mechanical mixer.
[0008] To monitor these process parameters, one periodically retrieves a sample of the wastewater from the processing zone, analyzes the sample, and then evaluates the results. Alternatively, sensors located in the aerobic and anoxic zones can periodically sense the desired parameter and provide the information to an operator, who then analyses and evaluates the information.
[0009] Disadvantageously, the prior art practice of having someone monitor the aerobic and anoxic process parameters and adjust the output of the blowers and mechanical mixers is time consuming and unnecessarily expensive. Because someone analyzes and evaluates the process parameters and then adjusts the blowers and mechanical mixers accordingly, the process takes time to complete resulting in concomitant costs in time and labor. Thus, for economical reasons, in practice the number of times the aerobic and anoxic process parameters are retrieved, analyzed and evaluated is kept to a minimum. If sensors are used someone typically still has to analyze and evaluate the information the sensors provide and then accordingly adjust the blower to the diffusers and/or mechanical mixer.
[0010] Furthermore, the typical prior art means for mixing the wastewater in the aerobic and anoxic zones is subject to several limitations. Mixing the aerobic zone with the movement of the tiny bubbles through the wastewater requires a substantial amount of tiny bubbles to be injected into the wastewater to sufficiently mix the wastewater. Disadvantageously, the demand for dissolved oxygen in the wastewater may decrease to the point where the amount of tiny bubbles injected into the wastewater to satisfy the demand would not be enough to sufficiently mix the wastewater. When this happens the amount of tiny bubbles injected into the wastewater is typically kept high enough to sufficiently mix the wastewater. Thus, the diffusers consume more power than required to oxygenate the wastewater and can inject more dissolved oxygen into the aerobic zone than required.
[0011] Mixing the aerobic and anoxic zones with a mechanical mixer consumes a large amount of power relative to the amount of wastewater that it mixes, and often mixes some, but not all, of the wastewater in each zone. Thus, some of the sludge in the aerobic and anoxic zones remains on the bottom of the tank after it settles there. In the aerobic zone, the settled sludge can plug some of the diffusers. This can reduce the amount of dissolved oxygen injected into the wastewater, and thus requires one to clear the plugged diffusers. Furthermore, when sensors are used to measure wastewater parameters, settled sludge can clog the sensors, resulting in erroneous wastewater parameter measurements.
BRIEF SUMMARY OF THE INVENTION
[0012] In one aspect of the invention, a system for treating wastewater includes a tank having an aerobic zone in which bacteria and other microorganisms convert pollutants in the presence of dissolved oxygen, and an anoxic zone in which bacteria and other microorganisms convert pollutants in the absence of dissolved oxygen to a more environmentally friendly form. The system also includes a blower and diffusers to inject dissolved oxygen into the aerobic zone, a mixer that generates large mixing bubbles, and a control system to monitor the aerobic and anoxic processes and adjust, accordingly, the output of the blower and mixer. For example, the control system can monitor the amount of ammonium and dissolved oxygen as the aerobic process progresses in the aerobic zone of the tank, and can monitor the amount of nitrate and ammonium as the anoxic process progresses in the anoxic zone of the tank. With the information obtained by monitoring these process parameters, the control system can then adjust the output of the blower and mixer accordingly. With the control system retrieving, analyzing and evaluating the process parameters, and then adjusting the output of the blower and mixer accordingly, someone does not have to perform these functions as the system treats wastewater.
[0013] The mixer generates large mixing bubbles, for example a bubble having a largest dimension of 6 inches to 10 feet, and is located in the aerobic and anoxic zones. The mixing bubbles are large enough to move wastewater as they rise to the surface and generate a mixing current in the wastewater. The mixing current mixes the wastewater, and bacteria and other microorganisms to promote the bacteria and other microorganisms' conversion of the pollutants contained in the wastewater. Because the mixer requires less energy than a typical mechanical mixer, the mixer costs less to operate. With the mixer mixing the wastewater in the aerobic zone the output of the blower can be reduced to match the demand for dissolved oxygen, which may be below the output required to mix the wastewater. In addition, the mixing bubbles are large enough that the amount of oxygen that they release into the wastewater as they move through it is negligible. Thus the anoxic portion remains anoxic as the large bubbles from the mixer rise toward the surface of the wastewater.
[0014] In another aspect of the invention, the system for treating wastewater can include a tank having one zone that can change processes over time as desired. For example, during the first six hours of a daily cycle, the tank can be used to aerobically process the wastewater and then during the next six hours of the daily cycle the tank can be used to anoxically process the wastewater. The ability to have the same zone of the tank available to process the wastewater aerobically and anoxically allows the wastewater treatment process to easily adapt to fluctuations in the amount of wastewater that can enter the treatment facility over time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The foregoing objects, as well as further objects, advantages, features and characteristics of the present invention, in addition to methods of operation, function of related elements of structure, and the combination of parts and economies of manufacture, will become apparent upon consideration of the following description and claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures, and wherein:
[0016] FIG. 1 is a schematic diagram of a typical wastewater treatment plant that includes a primary treatment process, a secondary treatment process, a tertiary treatment process, and a waste sludge treatment process;
[0017] FIG. 2 is a perspective view of a tank, a blower, a mixer, and a control system that are included in a system for treating wastewater, according to an embodiment of the invention;
[0018] FIG. 3 is a schematic diagram of the control system in FIG. 2 , according to an embodiment of the invention;
[0019] FIG. 4 is a flow chart of how the control system in FIGS. 2 and 3 monitors the aerobic and anoxic processes and accordingly adjusts the output of the blower and mixer, according to an embodiment of the invention;
[0020] FIG. 5 is a perspective view of a forming plate that is included in the mixer in FIG. 2 , according to an embodiment of the invention; and
[0021] FIG. 6 shows an embodiment with mixing bubbles that are generated by a mixer traveling through wastewater and mixing the wastewater.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] FIG. 1 is a schematic diagram of a wastewater treatment process that includes a primary treatment process, a secondary treatment process and a tertiary treatment process. The primary treatment process includes a clarification stage 10 a to separate dense portions of the wastewater, typically heavy solids, from less dense portions of the wastewater, typically light solids and liquid. The secondary treatment process includes a biological nutrient conversion stage 12 that converts the biological nutrient material contained in the light solids and liquid into a more environmentally friendly form. For example, in one embodiment, wastewater is first clarified into heavy solids, and light solids and liquid, in the clarification stage 10 a using conventional techniques. The heavy solids are directed to a sludge processing stage 14 that processes the heavy solids using conventional techniques. The light solids and liquid are directed to the biological nutrient conversion stage 12 where they are subject to an aerobic and anoxic conversion process as discussed in greater detail in conjunction with FIGS. 2 and 3 . During the biological nutrient conversion stage 12 , the bacteria and other microorganisms convert the nutrient material contained in the wastewater to a form that is more environmentally friendly. From the biological nutrient conversion stage 12 , the wastewater is directed to another clarification stage 10 b that clarifies the liquid and any remaining heavy and light solids using conventional techniques. From the clarification stage 10 b , the heavy sludge, which contains a predominance of bacteria, is partially directed to the sludge processing stage 14 that processes the heavy solids using conventional techniques and partially returned to the secondary treatment stage. The very light solids, along with liquid that does not contain excessive amounts of biologically nutrient material, is directed to the tertiary treatment process 16 where remaining pollutant material is removed from the wastewater.
[0023] FIG. 2 is a perspective view of a tank 18 , a blower 20 , a mixer 22 , and a control system 24 that are included in a system for treating wastewater, according to an embodiment of the invention. The tank 18 includes zones 26 a and 26 b in which bacteria and other microorganisms aerobically and anoxically convert pollutants in the wastewater to more environmentally friendly forms. In one embodiment, for example, the tank 18 includes two zones 26 a and 26 b , an inlet 28 through which wastewater enters the tank 18 , an outlet 30 through which wastewater exits the tank 18 after flowing through the zones 26 a and 26 b , and a portal 32 through which the wastewater leaves the zone 26 a and enters the zone 26 b . The zone 26 a includes bacteria and other microorganisms (not shown) that aerobically convert pollutants in the wastewater, and the zone 26 b includes bacteria and other microorganisms (not shown) that anoxically convert pollutants in the wastewater.
[0024] In addition, an Integrated Fixed-film Activating Sludge (IFAS) system that includes media (omitted for clarity) may exist in zones 26 a and 26 b . The media provides the bacteria and other microorganisms (not shown) a structure to hold onto and may be freely suspended in the wastewater. In other embodiments, the IFAS may include a net or web (not shown) that is anchored in the zones 26 a and 26 b . In still other embodiments the IFAS may include both the net or web and the media.
[0025] The blower 20 delivers air to the diffusers 34 ( 22 shown but only four labeled with a reference number for clarity) via distribution lines 36 . The diffusers 34 generate tiny bubbles (not shown) that travel through the wastewater toward the surface of the wastewater. As the tiny bubbles ascend through the wastewater, they release oxygen into the wastewater. Once the oxygen is in the wastewater, the bacteria and other microorganisms can use it to convert ammonium into nitrate.
[0026] The mixer 22 injects any fluid, such as air, that is less dense than the combination of the wastewater, bacteria and other microorganisms to generate large mixing bubbles (discussed in greater detail in conjunction with FIG. 6 ). The mixing bubbles are large enough to move a substantial amount wastewater as they rise toward the wastewater's surface, and thus generate a mixing current in the wastewater. The mixing current mixes the wastewater, bacteria and other microorganisms to promote biological activity for removal of pollutants from the wastewater.
[0027] The mixer 22 includes a forming plate 38 to form mixing bubbles from the injected fluid, and a valve 39 to permit or prevent the fluid from reaching the forming plate 38 . The mixer 22 also includes a distribution line 40 to supply the forming plate 38 with the fluid when the corresponding valve 39 is open. Each forming plate 38 , one embodiment of which is shown in FIG. 5 , includes an orifice 44 . When the valve 39 is opened, air flows through the distribution line 40 toward the forming plate 38 , and then exits the distribution line 40 through the orifice 44 . The forming plate 38 prevents the air from rising toward the surface of the wastewater until the valve 39 injects more air than the forming plate 38 can hold, at which time most of the air escapes from under the forming plate 38 and forms a large mixing bubble. The large mixing bubble then rises toward the surface of the wastewater. When the valve 39 is closed, air does not flow through the orifice 44 . For additional discussion on the forming plate 38 and an embodiment of an injector see U.S. Pat. No. 6,629,773, titled IMPROVED METHOD AND APPARATUS FOR GAS INDUCED MIXING AND BLENDING OF FLUIDS AND OTHER MATERIALS, issued to Parks on 7 Oct. 2003, which is herein incorporated in its entirety.
[0028] Still referring to FIG. 2 , the forming plates 38 may be arranged throughout the aerobic and anoxic zones 26 a and 26 b as desired to provide any desired mixing current arrangement. In one embodiment, the forming plates 38 are located a few inches above the bottom of the tank 18 . The forming plates 38 each may be located closer to the bottom of the tank 18 or further away from the bottom of the tank 18 in either or both zones. Preferred embodiments employ one or more forming plates 38 located on the bottom of tank 18 or at most a few inches above the bottom, in order to maximize the efficacy of the mixing afforded by the large bubbles.
[0029] As depicted in a preferred embodiment, the forming plates 38 are spatially arranged in the anoxic zone 26 b to form a rectangle with an additional forming plate 38 located in the middle of the rectangle. As will be appreciated by those in the art, numerous other spatial arrangements of the plates 38 are possible in each zone, including circular and other arrangements, as required for a given wastewater treatment system configuration.
[0030] Still referring to FIG. 2 the valves 39 may also be opened and closed in any desired sequence to provide any desired mixing current within each of the zones 26 a and 26 b . For example, in one embodiment, four valves 39 corresponding to the four forming plates 38 in the anoxic zone 26 b that are closest to the sidewalls of the tank 18 may first permit air to flow toward the forming plates 38 . Then, after these valves 39 have closed, the remaining valves 39 that correspond to the remaining forming plates 38 may permit air to flow toward the forming plates 38 . This sequence would cause a turbulence in the mixing currents generated by the four forming plates 38 and may promote mixing the wastewater, bacteria and other microorganisms through out the anoxic zone 26 b.
[0031] The control system 24 monitors the aerobic and the anoxic processes that occur in the respective zones 26 a and 26 b of the tank 18 . The control system 24 includes a controller 48 (discussed in greater detail in conjunction with FIGS. 3 and 4 ) that analyses and evaluates information regarding process parameters of both the aerobic and anoxic processes as these processes progress, and accordingly adjusts the output of the blower 20 and mixer 22 . The control system 24 also includes sensors 50 , 52 , 54 . 56 and 58 located in respective zone 26 a and 26 b of the tank 18 to sense certain process parameters and convey the information to the controller 48 via conventional means (not shown). Suitable sensors may be obtained from WTW Wissenschaftlich-Technische Werkstätten GmbH, of Weilheim, Germany.
[0032] In one embodiment, the sensors 50 , 52 and 54 are located in the aerobic zone 26 a , and sensors 56 and 58 are located in the anoxic zone 26 b . Sensor 50 senses the presence of dissolved oxygen in the wastewater in the aerobic zone 26 a , sensor 52 senses the presence of ammonium, and sensor 54 senses turbidity, which, as is known to those of skill in the art, correlates to total suspended solids (TSS). Sensor 56 senses the presence of nitrate in the wastewater in the anoxic zone 26 b and sensor 58 also senses turbidity to measure TSS. For additional discussion on the control system 24 see PCT Patent Application PCT/US2004/011248, titled APPARATUS AND METHOD FOR GAS INDUCED MIXING AND AGITATING OF A FERMENTING JUICE IN A TANK DURING VINIFICATION, filed 8 Apr. 2004 which is herein incorporated in its entirety.
[0033] FIG. 3 is a schematic diagram of the control system 24 in FIG. 2 , according to an embodiment of the invention. The control system 24 includes the sensors 50 - 58 and a controller 48 to analyze and evaluate the data generated by the sensors 50 - 58 , and generate instructions to adjust the outputs of the blower 20 and the mixer 22 . The controller 48 includes circuitry 62 that can store and generate data and instructions based on the data the circuitry receives from the sensors 50 - 58 , and a processor 64 to execute instructions stored or generated in the circuitry 62 . The controller 48 also includes an input 66 that one can use to enter data into the circuitry 62 . For example, in one embodiment, one can enter limits for the amount of dissolved oxygen, ammonium and nitrate that the controller 48 can compare with respective amounts determined to exist in the wastewater. One can also enter a limit for the degree of total suspended solids (TSS) in the wastewater in each of the zones 26 a and 26 b that the controller 48 can compare with the degree of TSS determined in each of the zones 26 a and 26 b . One can also enter a limit for the outputs of the blower 20 and mixer 22 that the controller 48 can compare with the output that the controller 48 determines should be used based on the data from the sensors 50 - 58 .
[0034] In other embodiments, the control system 24 may include a set of instructions to switch the data and instructions stored and generated by the circuitry 62 from those used to monitor an aerobic or anoxic process to those used to monitor an anoxic or aerobic process, respectively. This may be desirable when the tank 18 includes one zone that processes wastewater aerobically for a period of time and then process the wastewater anoxically for another period of time.
[0035] FIG. 4 is a flow chart of the control system in FIGS. 2 and 3 monitoring the aerobic and anoxic processes, and accordingly adjusting the output of the blower and mixer, according to an embodiment of the invention. In operation, the control system 24 can monitor the aerobic process while it monitors the anoxic process (as shown in FIG. 2 ), and can accordingly and independently adjust the blower and mixer outputs in the aerobic zone 26 a relative to the mixer output in the anoxic zone 26 b . As previously discussed, in other embodiments, the control system 24 can sequentially monitor one of the conversion processes and accordingly adjust the mixer's output or the blower and mixer's output, whichever is applicable.
[0036] In one embodiment, the control system 24 monitors the amount of TSS determined to be in the wastewater in the aerobic and anoxic zones 26 a and 26 b ( FIG. 2 ) during the aerobic and anoxic processes. When the level of TSS is determined to be less than a desired predetermined degree, the control system 24 instructs the mixer 22 to change one or more of the bubble generation parameters that the mixer 22 uses to generate mixing bubbles (discussed greater detail in conjunction with FIG. 6 ) to increase the TSS. For example, the mixer 22 may increase the frequency of the mixing bubbles that one or more of the forming plates 38 ( FIG. 2 ) generates and releases into the wastewater. When the level of TSS is determined to be greater than a desired predetermined degree, the control system 24 instructs the mixer 22 to change one or more of the bubble generation parameters to decrease the TSS. For example, the mixer 22 may decrease the size of each mixing bubble that one or more forming plates 38 generates and releases. The one or more bubble generation parameters that the control system 24 chooses to have the mixer 22 change depends on many variables that include the difference between the determined level of TSS and the desired level, how quickly one wants to correct this difference, and the capability of the mixer 22 .
[0037] In one embodiment, the control system 24 monitors the amount of dissolved oxygen and ammonium determined to be in the wastewater in the aerobic zone 26 a ( FIG. 2 ) during the aerobic process. The control system 24 then compares the determined amounts of ammonium and dissolved oxygen in the wastewater and then accordingly adjusts the output of the blower 20 ( FIG. 2 ). When the amount of ammonium is greater than a desired predetermined amount, and the amount of dissolved oxygen is less than a desired predetermined amount, the control system 24 instructs the blower 20 to change one or more of the parameters that define the airflow toward the diffusers to increase the amount of dissolved oxygen in the wastewater. For example, the blower 20 may increase the flow rate of air to the diffusers 34 ( FIG. 2 ) or the blower 20 may deliver air that has a higher concentration of oxygen to the diffusers 34 . When the amount of ammonium and dissolved oxygen is greater than respective, desired predetermined amounts, the control system 24 instructs the blower 20 to change one or more of the bubble generation parameters to decrease the amount-of dissolved oxygen. When the amount of ammonium is less than a desired predetermined amount, and the amount of dissolved oxygen is greater than a desired predetermined amount, the control system 24 instructs the blower 20 to change one or more of the parameters that define the airflow toward the diffusers to decrease the amount of dissolved oxygen in the wastewater. When the amount of ammonium and dissolved oxygen is less than respective, desired predetermined amounts, the wastewater is ready to be anoxically processed, and the control system 24 confirms that this portion of the wastewater is about to enter the anoxic zone 26 b . In other embodiments, the control system 24 switches from monitoring the aerobic process to monitoring the anoxic process while the wastewater remains in the same zone of the tank.
[0038] In one embodiment, the control system 24 monitors the amount of nitrate determined to be in the wastewater in the anoxic zone 26 b during the anoxic process. When the amount of nitrate exceeds a desired predetermined amount, the control system 24 confirms that this portion of the wastewater still has a significant amount of processing time to progress through. When the amount of nitrate is less than a desired predetermined amount, the control system 24 confirms that this portion of the wastewater is ready to leave the anoxic zone 26 b . If the amount of ammonium, which the control system 24 may also monitor in the anoxic zone, exceeds a desired predetermined amount, the wastewater is ready to be aerobically processed again, and the control system confirms that the wastewater is about to enter another aerobic zone (not shown). In other embodiments, the control system 24 switches from monitoring the aerobic process to monitoring the anoxic process while the wastewater remains in the same zone of the tank.
[0039] In addition, in one embodiment of the control system 24 the control system monitors the time of day that it receives specific data from the sensors 50 - 58 and analyzes and evaluates the data. By keeping track of the time of day, the control system 24 can compare the data it receives and generates with data that it should receive and generate for the time of day, and can determine whether or not a malfunction in the sensors 50 - 58 , blower 20 , mixer 22 and control system 24 might exist.
[0040] FIG. 6 is a view of one of the zones 26 a and 26 b in FIG. 2 . The mixing bubbles 68 generate the mixing currents indicated by the arrows 70 (28 arrows shown but only 5 labeled with the reference number 70 for clarity) that mix the wastewater 72 , bacteria (omitted for clarity) and other microorganisms (also omitted for clarity). The strength of the mixing currents depends on the speed at which each mixing bubble 68 travels through the wastewater and the size of each bubble 68 .
[0041] The speed of the mixing bubble 68 depends on the density of the fluid relative to the density of the wastewater 72 , and the bubble's shape. The greater the difference between the densities of the wastewater 72 and the fluid, the faster the mixing bubbles 68 rise through the wastewater 72 . The more aerodynamic the shape of the bubble 68 becomes, the faster the bubble 68 rises through the wastewater 72 . For example, in one embodiment, the bubble 68 forms an oblate sphere—a sphere whose dimension in the vertical direction is less than the dimension in the horizontal direction. In other embodiments, the bubble 68 forms a distorted oblate sphere having the trailing surface—the surface of the bubble 68 that is the rear of the bubble 68 relative to the direction the bubble 68 moves—that is convex when viewed from the direction that the bubble 68 moves.
[0042] The size of the mixing bubble 68 depends on the flow rate of the fluid into the wastewater 72 . The flow rate depends on the size of the orifice 44 and the fluid's injection pressure. As one increases the fluid-injection pressure, one increases the amount of fluid injected into the wastewater 72 over a specific period of time that the valve 39 is open. And, as one increases the area of the orifice 44 , one increases the amount of fluid injected into the wastewater 72 over a specific period of time that the valve 39 is open. As one increases the diameter of the forming plate 38 one increases the amount of fluid the forming plate 38 can hold before the fluid escapes it. For example, in one embodiment the size of the bubble 68 is approximately 6 inches across its largest dimension. In other embodiments, the bubble 68 is approximately 10 feet across it largest dimension.
[0043] While the invention has been described with a certain degree of particularity, it should be recognized that elements thereof may be altered by persons skilled in the art without departing from the spirit and scope of the invention. Accordingly, the present invention is not intended to be limited to the specific forms set forth herein, but on the contrary, it is intended to cover such alternatives, modifications and equivalents as can be reasonably included within the scope of the invention. The invention is limited only by the following claims and their equivalents.
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A system and method of wastewater treatment in a tank provides large mixing bubbles generated in the lower portion of the tank. In embodiments providing aerobic wastewater treatment, the system further provides oxygen to the wastewater by way of tiny aerating bubbles provided by diffusers. At least one sensor in the tank provides measurements of at least one wastewater treatment parameter such as total suspended solids, dissolved oxygen, ammonium or nitrate. An automatic controller in the system, responsive to measurements provided by the sensor, adjusts the rate of mixing provided by the large mixing bubbles. In some aerobic embodiments, the controller, responsive to measurements from the sensor, further adjusts the rate of oxygenation supplied to the wastewater by the tiny aerating bubbles.
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BACKGROUND OF THE DISCLOSURE
The present invention is directed to an apparatus and related method for obtaining an azimuthally directed measurement in a cased well borehole and more particularly in one provided with a production tubing surrounded by a gravel pack on the exterior of the production tubing and on the interior of the casing. It is particularly useful for wells into formations which are produced in this fashion, namely, by positioning a casing in the well borehole, cementing the casing in the well and subsequently forming perforations through the casing into the formation so that formation fluid production is obtained. In many wells, one problem is that there will be excessive sand production from a producing formation, and that is often countered by installing a gravel pack in the cased well. A typical arrangement involves a production tubing string centralized within a casing cemented in place with a gravel pack and sand screen supporting the gravel pack on the interior of the casing.
Gravel packing is performed to keep loosely compacted formations from eroding during production. Formation on erosion generally begins at or near the perforation tunnels where fluid flow velocities are highest. When this type of erosion occurs, there are several possible detrimental results such as formation fines which plug the formation and reduce or stop production; they may fill the casing stopping production, and they may be carried by the production stream where they can cause a variety of equipment damage.
The idea behind gravel packing is to fill the perforation tunnel with a permeable material which reduces the flow velocity. It is also desirable that this packing be of a similar pore size to the formation in order to further reduce the movement of formation fines. In the event that the perforation tunnel portion of the gravel pack is not completely successful, the annular portion of the pack inside the casing may act as a barrier to filter the formation material from being carried downstream by the fluid flow.
It is very difficult to measure how well the perforation tunnels are packed. However, much can be learned about the quality of the packing procedure by measurements which detect the uniformity of the annular portion of the pack inside the casing. It is desirable to detect both increases and decreases in gravel pack porosity which may indicate voids and plugging respectively.
Immediately after performing a gravel pack procedure, before flowing the well, voids in the annular area and inside the casing may indicate that the perforation tunnels were not sufficiently packed. It also, belies later problems in that even if the tunnels are well packed, the annular void provides a location for the flowing fluid to carry the pack material from the perforation tunnel into the casing thereby unpacking the tunnel. After a well is produced and there is a partial failure of the packing (some or many tunnels are not packed), the annular portion of the pack acts as a filter to prevent formation fines from moving downstream. Voids detected at this time indicate the reduced capability of this filtering material. This type of failure may also be indicated by the reduced packing porosity, production fluids into the casing at high flow velocities, they will actually erode the gravel pack screen itself if it is not protected by the annular portion of the pack. A work over is necessitated to correct the pack. Work overs interrupt production and cost substantial sums of money to provide service to a well. Even then, when the work over is complete, the pack in the well may sand up again.
In conjunction with gravel pack, a screen typically will be installed, namely a screen formed of screen wire or screen cloth which is inserted in the well borehole to prop up the gravel pack. This defines an annular support for the gravel. This is highly desirable to extend the life of a well.
It is possible to locate a void in the gravel with a tool which is responsive to density. Consider for instance a density measuring device where there is a substantial contrast between the fluid in the pores and the gravel. The fluid may have a density of about 1.0, but perhaps slightly more if it is salt water, and the gravel pack material might have a density of about 2.65 gm/cc. A loss of gravel pack material in a particular region will alter the matrix/fluid ratio and thus reduce the measured bulk density. Conversely, a pack plugging with formation fines will have an increased density. The density is inversely proportional to the detected count rate of a typical gamma ray fluid density tool used in this circumstance and can be employed to indicate gravel pack quality.
That type measurement is made all the more difficult as a result of recent advances which have been introduced for gravel pack materials. The contrast in the density of the matrix and fluid has been reduced with the advent of new packing materials. Regrettably, this makes measuring gravel pack quality more difficult. In other words, as the specific density of the matrix material decreases from a typical density of 2.65 down to 2.0 or perhaps even less, the loss in contrast in the density measurement between the matrix material and the pore fluid makes measurement the gamma density approach difficult, perhaps almost impossible. The present disclosure sets forth a method and apparatus which can be used to measure gravel pack quality that does not depend on a contrast between the fluid and matrix material densities.
BRIEF DESCRIPTION OF THE INVENTION
The present disclosure is directed to a sonde having an external housing which is adapted to be lowered into a well borehole on a logging cable. It is intended to be operated in a centralized position. Moreover, it incorporates a neutron source which is installed at a zero spaced detector to accomplish the measurement. Additionally, a second detector which is located remotely from the first detector can be used. The detectors cooperate with a neutron source capable of forming a neutron flux directed into the formation in the vicinity of the source where the neutrons react with the respective materials and are back scattered toward the detector. This relies on neutron back scatter as opposed to forward scattering and absorption which is involved in porosity measurements. With the source located at the center of the detector, fast neutrons leaving the source are back scattered to the detector only if they undergo large angle scattering to be returned to the detector. At this point the neutrons are generally at low energies, thermal/epithermal can be detected by an appropriate detector. The interaction with the environmental materials primarily involves the neutron back scatter and absorption in contrast with forward scattering and absorption involved in porosity measurements. The present system thus takes advantage of a zero spaced neutron source located at the center of the detector. A flux of fast neutrons from the source thus require the large angle back scattering for return to the area of the tool in the well borehole to interact with the detector. The detected neutron flux is predominately effected by the gravel pack material in the cased well. The constituent materials of the environment on the exterior of the casing are substantially not involved in the reaction yielding the detected back scatter neutrons. The primary reaction of value is the elastic collision with hydrogen nuclei which are found in the fluids in the spaces between the matrix material of the gravel pack. The detected count rate is thus proportional to the hydrogen content or porosity of the environment surrounding the source, and most especially is at such a distance or range from the source that other materials are not involved, thereby excluding neutron interaction with the formations to the exterior. This takes advantage of the fact that a typical thermal neutron diffusion path or length is typically just a few inches, not much more than about five inches, or even less. Thermal neutrons existing at greater distances are ultimately absorbed and not detected. This practically limits the range of investigation. This enables a zero spaced detector to be appropriately sensitive to the hydrogen nuclei in the immediate vicinity and therefore sensitive to and responsive to the pore fluid in the gravel pack matrix. The response is substantially insensitive to other materials beyond that area.
The source to detector spacing controls the effective radial depth. By use of a second detector which is axially aligned in the sonde but at some distance from the zero spaced neutron source in the first detector just mentioned, data can be obtained from the second detector which enables compensation for environmental effects. It provides a base line enabling a measurement which can then be employed with the readings of the zero spaced detector to especially eliminate such effects.
There is an additional factor involved in detection of thermal neutrons. The count rate of the detector is in part determined on the extent of materials which are thermal neutron absorbers. This includes elements such as chlorine or boron. With an unintended substantial increase in such absorbing elements, it is possible to have a false reading indicating gas or a tighter packing of the gravel pack than is actually resident in the area. It is helpful to provide a correction to account for variations in the thermal neutron absorbing elements. In other words, if there is a uniform distribution of absorbing elements, the log can be calibrated to take this fact into account. If however variations arise from variations in absorbing elements, that fact needs to be recognized and removed from the data before determination of the log quality. To accomplish this it may be helpful to incorporate a neutron detector which is sensitive to neutrons having energies above the thermal level. This can be accomplished simply by wrapping the detector element with a cadmium shield which will eliminate thermal neutron flux, thereby providing a detector which is far less sensitive to thermal neutrons and hence far less sensitive to the presence of thermal neutron absorbing elements. That can be used to provide a measurement where the count rate corrects for the variations in absorbing materials. In addition to cadmium, other suitable materials are samarium, carbon, gadolinium and boron. It is one advantage of the present apparatus to incorporate a shield with a detector subject to rotation about the detector to vary the azimuthal neutron flux impingement on the detector. Consider as an example a shield around the detector which encircles the entire detector save and except a lengthwise window of specified width, for example something between 10° and 30° . The shield markedly cuts down the count rate. Assuming that the count rate remains sufficiently high to have some degree of statistical reliability, the shield when rotated provides an azimuthal response indicative of the directional orientation. This enables determination of voids in the gravel pack matrix as a function of direction with respect to the axis of the logging tool. Moreover, the window in the shield permits a response which includes thermal neutrons as well as those of higher energy levels. At the risk of reducing the count rate so low that statistical reliability is not well established, an alternate embodiment is set forth wherein the shield is of specific angular extent and omitted elsewhere. For instance, the shield can have a width of 60° and 300° be omitted; on rotation through one full revolution, the angular location of the 60° shield can be correlated to changes in measured neutron flux accomplished at a much higher count rate; this is desirable to increase the count rate for enhanced statistical reliability.
As a generalization, the method and apparatus of the present gravel pack investigative system involves a determination of gravel pack quality, and is relatively insensitive to eccentering, and is additionally relatively insensitive to material variations on the exterior of the casing. Thus, the data from such a system is primarily related to the nature of the matrix between the screen and the casing, and therefore provides a good indication of quality.
While the foregoing speaks very generally about the present system, and provides something of a summary of the equipment and the method of obtaining such a measure, there is a specific description of the present invention set forth below in specific embodiments which will be detailed. It is appropriate however to summarize very generally the present apparatus as typically including a zero spaced source and detector enabled to form a fast neutron flux which reacts with the materials in the gravel pack and wherein back scatter neutrons are detected by the detector. An azimuthal feature is included derived from a rotated shield where the shield is quite substantial with a narrow window or the reverse of the shield is used. A second detector spaced lengthwise along the supporting sonde is included to make base line measurements. The system relies on back scatter from the materials making up the gravel pack and to that extent, it is responsive to those materials in the immediate vicinity, yielding a shallow depth of investigation which is directed to the region where the gravel pack is located.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a sectional view through the gravel pack logging tool of the present disclosure showing the tools suspended in a production tubing in a well which is provided with a gravel pack and screen located in the cased well borehole;
FIG. 2 is a sectional view through a tool detector system in accordance with the present disclosure;
FIG. 3A is a sectional view through a detector showing a zero spaced radiation source on the interior in conjunction with a detector and segment of a shield thereabout;
FIG. 3B is a view similar to FIG. 3A showing the same detector with similar shield material wherein FIG. 3B differs in that the shield fully extends around the detector and has a small window;
FIGS. 4A and 4B show a graph of the count rate versus porosity. See corrected FIGS.
FIGS. 5A and 5B are graphs similar to FIGS. 4A and 4B;
FIG. 6 is a graph showing the count rate as a function of a step change in density/porosity along the axis of the well borehole; and
FIG. 7 shows porosity apparent readings of a gamma porosity and a neutron porosity measurement so that the two curves aid in identifying the condition of a gravel pack in a well borehole.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is now directed to FIG. 1 of the drawings where the numeral 10 identifies a sonde which is constructed in accordance with the teachings of the present disclosure and further wherein the sonde supports a measuring system as described below. Before going to the specifics of that, the location in which the sonde 10 is used should be described in conjunction with the equipment incorporated in FIG. 1 which enables the sonde to be lowered into a well borehole for obtaining measurements indicative of gravel pack quality. This therefore involves a description of the supportive equipment cooperative with the sonde, and also sets forth a detailed description of the cased well and various aspects regarding it.
The sonde incorporates a closed and sealed housing 12 which is provided to operate at elevated temperatures and pressures while protecting the equipment on the interior. The equipment on the interior incorporates a radiation source 14 which will be described in detail. The source may be external (like a band) around the detector without effecting measurement. It is shown located internally of a first detector 16, and is spaced along the length of the tool from a second or far detector 18. The detectors 16 and 18 provide output data in the form of measured counts indicative of the impingement of backscattered neutrons in the region of the detectors 16 and 18. Moreover, the equipment utilizes telemetry circuits to provide the count rates on one or more conductors which are extended through and along a logging cable 20 which supports the sonde 10 in the well. Typically, the sonde is lowered to the bottom of the well and is retrieved by moving upwardly in the well. This enables measurement of the sonde location supported on the logging cable 20. The cable 20 passes over a sheave 22 at the surface and is spooled onto a large storage drum 24. The cable 20 includes one or more signal conductors which provide signals to the surface and these signals are continued from the logging cable to a surface computer 26. Calculations by the computer 26 are output to a recorder 28. The data is recorded as a function of depth. Depth measurement is obtained by an electronic or mechanical depth measuring system 30 which connects with the sheave 22 and provides a depth measurement.
In the well, the numeral 32 identifies the casing which is held in position with the hole in the earth's formations by a layer of cement 34. The completed well is perforated at 36 into a producing formation 40. There are typically many perforations. They produce formation fluid from the formation 40 which flows through the perforations and to the interior of the cased well. As shown, the perforations permit this fluid flow to drain into the cased well borehole typically flowing as a result of a positive formation fluid drive.
There is always the risk that the formation will produce sand along with the fluid mixture, typically, a mixture of oil and water. The sand from the formation will flow through the perforations and tends to plug or choke the well because the sand will typically accumulate adjacent the zone 40 where production is achieved. As the sand is produced, it collects in the cased well above the packer (not shown) which defines the isolated zone. The packer defined zone will normally accumulate the sand until the sand completely clogs the system and prevents proper production of the formation 40.
The well of the present disclosure is provided with an improved production apparatus which includes a gravel pack 42. The gravel pack is formed of gravel like material arranged in an annular space on the exterior of a cylindrical screen 44 which holds the gravel in place. The produced fluid can percolate through the gravel pack, and the sand that is in the produced fluid will tend to settle toward the bottom. The gravel pack therefore serves the desirable purpose of providing a serpentine and multifaceted flow path for the production fluid flow. It is not as vulnerable to silting which might otherwise tend to plug the well. The gravel pack maintains this protection between the perforations into the formations and the screen 44. Generally, the screen is intended to be concentric about the well, centered between the casing 32 and the production tubing 46 which is arranged in the well. In similar fashion, the sonde 10 is centralized in the tubing 46 by centralizers on the sonde 10 the centrilizers being omitted for sake of clarity.
Ordinarily, production flows from the perforations 36 and into the gravel pack 42. The production flow continues radially inwardly above the bottom packer (not shown) which defines this production zone 40. The production of fluid from the perforations 36 through the gravel pack 42 and then through the screen 44 continues through the production tubing 46 perforated at 48.
After a well has been operated for an interval, there may be the risk of settling or other types of segregation in the gravel which makes up the gravel pack. It is therefore helpful to periodically test the well for integrity of the packing material in the well. A loss of integrity is typically evidenced by a large void or plugging in the gravel pack. The present apparatus is a system which is intended to accomplish this.
As shown in FIG. 1 of the drawings, the numeral 14 identifies a source of neutrons. These are relatively fast neutrons, sufficiently fast that they are not detected by the detector 16 because they have energy levels which are excessive for detection thereby. The detector 16 more aptly responds to thermal neutrons. The numeral 50 represents a typical backscattering pathway whereby a neutron is emitted from the source 14 and is deflected along its pathway and returned by means of backscatter reactions toward the detector 16. The detector 16 is at zero spacing from the neutron source 14. By that, it is meant that both are located at a common location. The common location is occasioned by positioning the neutron source at the center of the detector. The detector is not responsive to extremely fast neutrons which are emitted from the source. Thus, in that sense, the detector is transparent to high energy neutrons. It is not transparent however to thermal neutrons which are returned in the backscattering approach chosen for the present disclosure. This system is different from other types of systems which typically utilize a forward scattering approach.
The hypothetical neutron path 50 has been exaggerated in length to provide a representative example of this backscattering. As a practical matter, the neutrons which are emitted from a source are provided with energy levels great enough that the neutrons penetrate beyond the casing 32 into the adjacent formations. However, neutrons thermalized at this distance will not have sufficient energy to return to the detector. There is a limited range at which backscattering can occur. In part, that depends on the type of materials that are in the immediate area and also depends on the type of interaction that occurs between the backscattered neutrons and the matrix of materials which are irradiated by the neutron emissions. For this reason, it is desirable to position an independent neutron measuring device which is able to provide readings of thermal energy neutrons which are returned from the immediate vicinity. As a generalization, the backscatter range of neutrons emitted by the present apparatus is only three to five inches. At ranges beyond that, it is rather improbable that the neutrons will be backscattered and measured. As a practical matter, this means that the responsive area is within the casing, and it generally does not involve the regions external to the casing. In other words, the steel which makes up the casing, the cement which lines the well borehole and the materials which make up the earth's formations adjacent to the well are generally not involved in the backscatter reaction. The neutron source 14 (a source of fast neutrons) might be Cf-252 or alternately AmBe-241. The curves of FIG. 4 show porosity responses for the latter type source while the curves in FIG. 5 show responses for the former neutron source. To the extent that such a source can be adapted and used, it is normally located at a finite point, being structurally relatively small so that it can be located as shown in FIG. 1 of the drawings. An alternate source is an encircling ring or band of appropriate material. The detector is typically an He-3 detector system.
In FIG. 1 of the drawings, both the detectors 16 and 18 are formed of the same type detector systems, preferably being He-3 detectors, and they typically have approximately equal size. If anything, the detector 18 can be made larger so that it provides an increased count rate as a result of the increase in size. This will tend to increase the count rate to over come the reduction in count rate which results from the greater linear spacing between the source 14 and the detector 18.
Noting that the backscatter range provides a depth of investigation of only 3 to perhaps 5 inches, the system of the present disclosure is able to irradiate the gravel packing materials quite readily without obtaining data from the region beyond the casing. This reduces the difficulties in elimination of environmental effects. These effects are even further reduced by obtaining a recording as a function of depth of the detector 18. Because of the greater spacing between that detector and the source, the primary purpose of the detector 18 is to provide a measurement which can be used to correct the small environmental effects in data from the detector 16.
Going now to other views in the drawings, the numeral 60 identifies a modified collimation source or system. The system shown in FIG. 2, the numeral 52 identifies the neutron source which is located within the detector 54. Again, the detector can be a typical He-3 detector which is isolated in that region. There is a suitable gap 56 which enables the emitted neutron flux to flow out through a steel shell 58 which defines the structure of the sonde. There are upper and lower shielding at 62 and 64 which is preferably formed of B 4 C which serves as a collimator to direct the neutron flux out to the gap or window at 56. This system provides a radially outwardly directed neutron flux.
Using FIG. 2 as a representative irradiation source which provides a flux radially outwardly into the gravel pack region, FIG. 6 shows the vertical response of such a source as that shown in FIG. 2. This shows that a 10% to 90% detector response is achieved in 8 cm. for a step porosity charge of 0% to 40% (i.e. 2.65 gm/cc to 1.99 gm/cc for a matrix with density 2.65 gm/cc and fluid of 1.0 gm/cc) along the borehole. Should the gravel pack be located further, from the sonde, the curve would tend to be flattened and less sharply defined. Should there be no vertical collimator, the curve likewise would have reduced vertical resolution. In summary, FIG. 6 shows certain aspects of the vertical response and resolutions which might be achieved in the context of this type or extent of vertical collimation.
Typical thermal neutron detectors, such as He-3 proportional counters, are sensitive to detecting both thermal and epithermal neutrons. The relative sensitivity to one or the other is determined by gas pressure and shielding. To detect primarily epithermal neutrons, gas pressure is increased thereby raising epithermal neutron detection efficiency and the detector is also surrounded by a primarily thermal neutrons, lower gas pressures are used to reduce the portion may still be counted. FIGS. 3A and 3B illustrate detector systems for performing azimuthally sensitive thermal neutron detection employing a difference in technique for removing the epithermal neutron contribution.
FIGS. 3A and 3B show detector systems which each include two stacked cylindrical detectors 54 and a neutron source located at the interface of these detectors. The source 52 may be positioned at the axis of the detectors or as a band or ring around the perimeter of the detectors at the same interdetector interface. A single position sensitive detector can be used. In both instances, it is preferable to utilize a motor which rotates the surrounding shield through 360° of rotation with respect to a vertical axis coincident with the tool axis and the detectors. A motor M is included for this purpose. It is connected to rotate the shield. As a practical matter, the shield can be affixed to the detector and the two can be rotated together by the motor. Radiation from the fast neutron source is normally omnidirectional so that it has no directional preference. Likewise an unshielded detector or one with a uniform shield does not have a directional preference. They respond in all directions. A directional preference defined by a window is incorporated by placing shielding material such as cadmium of the requisite thickness on the detector. Comparing the two views, the construction in FIG. 3A enables the detector to receive a higher count rate because the amount of shielding is reduced. Since the shielding is reduced, the count rate is higher but the angular discrimination is reduced. By rotating the shield 72 for a full revolution at a fixed elevation, it is possible to obtain azimuthal discrimination for the detector. By contrast, the construction shown in FIG. 3B provides a reduced count rate but sharper azimuthal discrimination. The shield fully encircles the detector except for the small window.
The shields can have an angular extent which can be varied. To have a modest reduction in the direction of azimuth of interest, the shield 72 is preferably in the range of perhaps 15° to 45° in arc. In one embodiment, the detector may be shielded with a shield of up to about 75° azimuthal angle. The window in the shield 74 can be of that size. As will be understood, in both instances azimuthal resolution is impacted by the shield and window angular size. The advantages of the embodiment in FIG. 3A are therefore an increased count rate but at the cost of reduced recognition of adjacent voids in the gravel pack material while the embodiment in FIG. 3B provides enhanced resolution but at the cost of operating at a reduced count rate. The latter is desirable to the extent that sharp definition is obtained so long as the count rate is sufficiently high to have statistical reliability.
In operation, the rotated shield window mechanism shown in Figs. 3A and 3B enables resolution of a nearby void in the gravel pack material. This is accomplished even in face of reduced density contrast between the packing material and the fluid which fills the gravel pack region. Thus, there is less contrast in the advent of gravel pack materials having a density of perhaps 1.8 as opposed to 2.65 gm/cc which had prevailed in years past. Consider as one example, a 40% porosity fresh water sand associated with a desirable or proper gravel pack in the cased well; neutrons emitted from the fast neutron source are thermalized in the gravel pack region and are backscattered to the detector. This provides a response for one cycle of rotation of the shielding around the detector (it being recalled that the detector functions in an omnidirectional fashion except where shielding makes some impact; either the shield can be rotated or both the shield and the detector can be rotated). Simultaneously, a reading is taken from the detector 18. The latter provides a curve, with appropriate sizing, of the background and permits the background reading to be deducted from the reading of the rotated detector system thereby enabling removal of background variations during the interval of recording the data during one revolution.
In FIGS. 3A and 3B, it is desirable to position two similar detectors serially where the first detector in FIG. 3A has the partial shield and the second has no shield. Likewise, FIG. 3B shows a first detector which is a substantially shielded with a window and the second detector has a complete shield.
Approximations of the count rates observed in the two detector schemes shown in FIGS. 3A and 3B are a function of the surface area of the detector and the neutron flux per unit surface area per unit of time. The following six equations thus describe the situation with the shield and detector arrangement shown in FIG. 3A and 3B: using the notations C 1 and C 2 to describe generally the count rate at the two adjacent detectors.
C.sub.1 =A(φ.sub.t +φ) (1a)
C.sub.1 =Aφ (1b)
C.sub.2 =(A-A.sub.s)(φ.sub.t +φ)+A.sub.s (φ) (2a)
C'.sub.2 =A.sub.s φ+(A-A.sub.s)(φ.sub.t +φ) (2b)
C.sub.16 =C.sub.1 -C.sub.2 =A.sub.s φ.sub.t (3 a)
C'.sub.16 =C'.sub.2 -C'.sub.1 =(A-A.sub.s)φ.sub.t (3 b)
In the foregoing, C 16 and C 16 the count rate in the detector 16 of FIG. 1 provided with the shield system shown in FIG. 3A or 3B respectively. The symbol A s is the surface area of the shield and the A represents the surface area of the detector. The symbols Φ t and Φ represent the thermal and the above thermal energy neutron flux backscattered to the surface of the detectors. The count rate, C 16 is the thermal flux in the direction of the shield strip. The count rate C 16 is the thermal flux entering through the inshielded window. These differences in measurements enable the thermal counts to be separated from the epithermal. This is normally a problem because many neutron detectors, such as He-3, are sensitive to neutrons of both energies.
The contrast between FIGS. 4 and 5 show the difference in the relative detected count rate from AmBe-241 and Cf-252 respectively. Otherwise, FIGS. 4 and 5 are identical except for this change. The contrast between FIG. 4A compared with FIG. 4B (and also comparing FIG. 5A to 5B) shows the contrast in response for thermal and epithermal detectors. The data indicates relatively good sensitivity to porosity. The data shown in FIGS. 4 and 5 thus shows that the gravel pack material provides the necessary response and that variations in porosity can then be used to locate voids in the gravel pack material.
FIG. 7 of the drawings shows measurements of porosity in the ordinant with variations in gamma porosity and neutron (zero spaced porosity). The notations across FIG. 7 show a good gravel pack, and then a poor gravel pack. In the presence of natural gas, the curve of FIG. 7 at 80 shows a good gravel pack while a poor gravel pack is shown at 82. Note the difference in the readings. Finally, the curve at 84 shows another good gravel pack indication.
The separation of the apparent porosity responses using these measurements enables pack quality to be determined even in the presence of natural gas or high-thermal neutron absorber concentrations.
While the foregoing is directed to the preferred embodiment, the scope thereof is determined by the claims which follow:
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An apparatus (sonde) and method of measuring density, or gravel pack quality, in a cased well borehole using a fast neutron source and one or more thermal neutron detectors is described. In one embodiment, a neutron source creates a fast neutron flux which reacts primarily with the material within the borehole casing while a collocated neutron detector counts the number of backscattered thermal neutrons. A novel means of obtaining azimuthal measurement discrimination is provided by a rotating neutron shield. In one instance the shield is quite substantial, creating a narrow measurement window. In another instance, the shield only marginally screens the detector, creating a large measurement window. In an alternative embodiment, a second thermal neutron detector is spaced distally from the neutron source and first detector. This second detector is used to provide a measurement of the borehole's background, or environmental neutron activity, and can be used to improve the quality of the sonde's gravel pack density measurement.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is related to the field of pile anchor foundations for supporting tall, heavy and/or large towers or the like which can be subject to high upset forces. More particularly, the present invention is directed to a perimeter pile anchor foundation including a plurality of pile anchors drilled in a circular or generally circular pattern so that adjacent piles overlap and form an arch with compression between the piles to resist soil caving in weak soils.
[0003] 2. Description of the Related Art
[0004] In known pile anchor foundations, the piles extend downwardly from a foundation cap into the underlying soil and are spaced from one another. Such foundations are limited by soil conditions, as weak or wet soils will cave or sluff when, during construction, the ground under the center of the cap is excavated vertically.
[0005] Various forms of concrete foundations utilizing operational features of the instant invention have heretofore been disclosed in my earlier U.S. Pat. Nos. 5,586,417, 7,707,797 and 7,618,217 (“the '217 patent”), the disclosures of which are expressly incorporated herein in this application by reference as if fully set forth in their entirety. However, a need exists for a large deep concrete foundation capable of being constructed in cohesionless sands and weak soils with shallow ground water.
SUMMARY OF THE INVENTION
[0006] In view of the foregoing, the present invention is directed to a perimeter pile anchor foundation for supporting tower or other structures which may be subject to high upset forces. The foundation is built by drilling a plurality of individual perimeter pile anchors, or “piles”, in a large circular or generally circular pattern. The individual piles are contiguous, each pile overlapping the adjacent piles on either side.
[0007] To construct the overlapping piles, the piles are divided into odd and even piles which alternate with one another around the perimeter of the foundation. Either the odd or the even piles may be constructed first. For purposes of this description, the odd piles are selected for forming first. The odd piles are formed by drilling a vertical hole for each pile, filling the hole with concrete, and inserting a centralized bolt vertically in the concrete (the order of the last two steps could be reversed). (The centralized bolts may later be post-tensioned, although post-tensioning is not necessary for the pile anchor bolts.) The concrete in the odd piles is then allowed to preset to a limited degree.
[0008] The even piles are arranged in between the odd piles. Therefore, after the concrete of the odd piles has preset, adjacent vertical holes are then drilled. Since the holes overlap to some extent, the concrete of the odd piles is shaved as the auger forms the hole for the even piles. The holes for the even piles are then filled with concrete and provided with vertically oriented centralized bolts in the same manner as with the odd piles.
[0009] In one preferred embodiment, the even and odd piles are offset from one another so that the diameter of the circle formed by the even piles is different from the diameter of the circle formed by the odd piles. This offset is typically in the range of one quarter to one half of the pile diameter. As a result, the total perimeter formed by the odd and even piles together is not a perfect circle.
[0010] Once the perimeter piles have been formed with the concrete fully set, an annular steel plate formed as a ring having holes therein is then placed on top of the perimeter piles. The centralized pile bolts extend through the holes and are secured with nuts to retain bolt tension. Alternatively, the ring may be formed by a plurality of individual steel plates, one for each pile. Individual steel plates provide for greater flexibility with respect to the adjoining relationship of the piles and the centralized pile bolts.
[0011] The perimeter piles form a perimeter wall to stabilize and retain the soil outside the wall. The soil inside the perimeter wall can then be safely excavated to form the large deep concrete foundation with the perimeter wall, without the soil caving or sloughing into the excavation.
[0012] An annular steel plate formed as a ring having holes therein is then placed on top of the perimeter piles. The centralized pile bolts extend through the holes and are secured with nuts to retain bolt tension. Alternatively, the ring may be formed by a plurality of individual steel plates, one for each pile. Individual steel plates provide for greater flexibility with respect to the adjoining relationship of the piles and the centralized pile bolts.
[0013] According to a first embodiment, a first corrugated metal pipe (CMP), also referred to herein as the outer CMP, is placed vertically in the excavation inside the perimeter wall formed by the contiguous piles leaving an outer annular space between the inside of the perimeter wall and the outside of the outer CMP. A foundation bolt cage, including a plurality of vertically oriented sleeved tower anchor bolts and a horizontally oriented embedment ring, is installed vertically inside the first CMP with the embedment ring at the bottom. According to a first configuration of the first embodiment, the tower anchor bolts are arranged in two concentric circles. In a second configuration of the first embodiment, the bolts are arranged in a single bolt circle. The tower anchor bolts, whether arranged in a single circle or in two concentric circles, are nutted above and below the embedment ring to secure the embedment ring in place near the bottom of the tower anchor bolts and concrete foundation to be formed. A second CMP, also referred to herein as the inner CMP, and smaller in diameter than the first CMP, is installed vertically inside the tower anchor bolts and the embedment ring. This creates an inner annular space between the outer and inner CMPs through which the tower anchor bolts extend vertically.
[0014] A concrete plug is then poured in the bottom of the inner CMP, after which the area inside the inner CMP atop the plug is backfilled with soil to approximately five feet below the surrounding ground surface. Electrical, communication, and grounding conduits are installed through the first and second CMPs, the tower anchor bolts, and the perimeter piles, and then backfilling of the inner CMP is completed to within a minimum of about six inches from the top of the inner CMP for the concrete floor 61 . The inner annular space between the outer and inner CMPs through which the tower anchor bolts extend vertically is filled to within about three to four inches from the top of the CMPs to create a grout trough. The outer annular space between the inside of the perimeter wall and the outer CMP, and the floor 61 inside the inner CMP, are then filled with concrete. Once the concrete cures, shims are stacked as necessary to support level the tower base section for grouting, the three to four inch grout trough filled with grout, and the tower base section flange set over the tower anchor bolts on top of the shims and nutted at the top against the upper surface of the tower base flange so that the tower anchor bolts can be post-tensioned when connecting and securing the tower to the foundation. The embedment ring is locked into place near the bottom of the foundation by the nutted tower anchor bolts.
[0015] According to a second embodiment, after the perimeter piles are formed, only a single CMP, such as the inner CMP is vertically placed in the excavation inside the pile perimeter and spaced therefrom to create an annular ring between the CMP and the piles. A direct embedded section is suspended in position between the piles and the inner CMP. The direct embedded section includes a reinforcing steel cage formed by a loop of rebar having a generally U-shaped cross-section. The loop includes a piece of rebar bent to have a generally vertical inner leg and a generally vertical outer leg joined at the top by a generally horizontal length of the rebar. The bottom of each leg is secured in place with rebar spacing hoops that are wire tied to the leg. The direct embedded section also includes an extension with flanges at the top and bottom thereof. The extension extends above the top of the concrete poured in the annular ring and is used to connect the foundation to the tower to be supported thereon. The direct embedded section takes the place of the tower anchor bolts and embedment ring that are part of the first embodiment.
[0016] The remainder of the construction of the second embodiment of the foundation is essentially the same as that already described in connection with the first embodiment, including the pouring of a concrete floor or plug and partial backfilling inside the inner CMP, installation of electrical, communication, and grounding conduits, completion of the backfilling of the inner CMP, and pouring of concrete into the annular ring between the inside of the perimeter wall and the CMP.
[0017] When constructed according to either the first or the second embodiment, the ring of overlapping odd and even piles forms an arch between adjacent piles. Compression and friction between the adjacent piles resists soil caving and sloughing pressure when soil inside the generally circular perimeter of the piles is excavated.
[0018] Accordingly, one object of the present invention is to overcome the difficulties of constructing deep concrete foundations in weak soil and/or cohesionless sand which are subject to sloughing or caving in when excavated vertically by providing a perimeter pile foundation.
[0019] Another object of the present invention is to provide a perimeter pile foundation in accordance with the preceding object that is formed by drilling a plurality of individual pile holes in a large generally circular pattern and filling them with concrete to form a perimeter wall, with the individual piles being contiguous and each pile overlapping the adjacent piles on either side so that the overlapping piles form a continuous arch, with compression between the overlapping piles resisting soil caving and sloughing pressure when soil inside the circle of piles is excavated.
[0020] Another object of the present invention is to provide a perimeter pile foundation in accordance with the preceding objects in which a vertical bolt is placed into the concrete of each of the perimeter piles before the concrete stiffens, the bolts extending substantially throughout the length of the pile anchor from top to bottom and having centralizers at one or more intervals along the length of the bolts to keep each bolt in the middle of its respective pile.
[0021] Yet another object of the present invention is to provide a perimeter pile foundation in accordance with the preceding objects in which a circular steel ring is placed over the top of the piles, the ring having holes therein through which the pile bolts extend and are secured with nuts to retain bolt tension.
[0022] A further object of the present invention is to provide a perimeter pile foundation in accordance with the preceding objects in which a central annular ring or foundation ring of concrete is poured inside the circular pile perimeter, the central foundation ring being provided with structure connecting elements placed in the concrete before the concrete stiffens.
[0023] A still further object of the present invention is to provide a perimeter pile foundation in accordance with the preceding objects in which the central foundation ring of concrete is bounded on the outside by the perimeter piles and on the inside by a first corrugated metal pipe (CMP).
[0024] Yet another object of the present invention is to provide a perimeter pile foundation in accordance with the preceding objects in which the structure connecting elements include an embedment ring and a plurality of post-tensioned tower anchor bolts.
[0025] A further object of the present invention is to provide a perimeter pile foundation in accordance with the preceding two objects in which the foundation further includes a second CMP placed inside the first CMP creating an inner annular ring between the first inner CMP and the second outer CMP, with the tower anchor bolts extending through the inner annular ring which is filled with concrete to complete the tower anchor bolt installation, both the inner and outer CMPs being inside the perimeter piles.
[0026] Yet another object of the present invention is to provide a perimeter pile foundation in which the structure connecting elements include a direct embedded section including a reinforcing steel cage secured to a generally cylindrical embedded structure extension having a side wall with a flange at each of its upper and lower ends.
[0027] Yet still another object of the present invention is to provide a perimeter pile foundation in accordance with the preceding objects in which concrete is poured to fill the entire volume within the circular pile perimeter.
[0028] It is yet another object of the invention to provide a perimeter pile foundation that is not complex in structure and which can be constructed at low cost and is effective in weak saturated soils and/or cohesionless sand that will not allow conventional concrete foundation excavations due to sloughing and caving in of such soils.
[0029] These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a sectional view of a perimeter pile foundation having two tower bolt rings in accordance with a first embodiment of the present invention.
[0031] FIG. 1 a is a top view of a circular arrangement of overlapping pile anchors in accordance with the perimeter pile foundation shown in FIG. 1 with the odd and even piles offset from one another.
[0032] FIG. 2 is a sectional view of a second configuration of the first embodiment of the perimeter pile foundation having a single tower bolt ring in accordance with the present invention.
[0033] FIG. 3 is a side view of single pile anchor and bolt, like that shown in FIG. 2 , in isolation and without centralizers.
[0034] FIG. 4 is an enlarged view of “Detail A” shown in FIG. 3 .
[0035] FIG. 5 is an enlarged view of “Detail B” shown in FIG. 3 .
[0036] FIG. 6 is a top view of a circular arrangement of overlapping pile anchors in accordance with the perimeter pile foundation shown in FIG. 1 , in which the odd and even piles are not offset from one another.
[0037] FIG. 7 is a side view of the tops of three adjacent pile anchors with the bolts secured on overlapping individual steel plates.
[0038] FIG. 8 is a photograph showing a perspective view of five adjacent pile anchor bolts extending upwardly through individual steel plates that are not overlapping.
[0039] FIG. 9 is an enlarged top view of two overlapping piles as shown in FIG. 6 .
[0040] FIG. 10 shows a sectional view of a second embodiment of the perimeter pile foundation in accordance with the present invention.
[0041] FIG. 11 is a perspective view of the extension of the direct embedded section shown in FIG. 10 .
[0042] FIG. 12 shows a deep concrete perimeter pile anchor foundation in accordance with the present invention supporting a large tower.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] In describing preferred embodiments 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.
[0044] A first embodiment of a perimeter pile anchor foundation in accordance with the present invention is shown in FIGS. 1 , 1 a and 2 . The perimeter pile anchor foundation, generally designated by reference numeral 10 , has a plurality of pile anchors or “piles”, each generally designated by the reference numeral 14 extending vertically downward into the soil 100 and forming a perimeter wall, generally designated by reference numeral 11 , for the foundation 10 . The pile anchors 14 thus serve to secure the concrete foundation 10 into the ground. A first or outer CMP 68 is placed vertically in the excavation inside the perimeter wall 11 to form an outer annular ring, generally designated by reference numeral 73 , between the inside of the perimeter wall 11 and the outer CMP 68 .
[0045] According to the first embodiment, a second or inner CMP 70 is placed inside the outer CMP 68 , forming an inner annular ring, also referred to herein as the foundation ring 72 . Extending through the concrete foundation ring 72 is a series of tower anchor bolts 18 spaced circumferentially in a circle about the central vertical axis of the foundation. The inner annular ring 72 is filled with concrete 12 either before or after placement of the tower anchor bolts.
[0046] The tower anchor bolts 18 can include two bolt circles as in the configuration shown in FIGS. 1 and 1 a , or one bolt circle as in the configuration shown in FIG. 2 . When using a one bolt circle, the bolts and the tower base flange 120 are inside the tower shell, a configuration known in the art as an L flange. With two bolt circles, generally designated by the reference numerals 20 and 22 , the bolt circles are positioned in radial pairs and can be used if the tower base flange 120 of the supported tower has a dual bolt circle, with one set of bolts being outside the tower shell 111 and one set of bolts inside the tower shell, resulting in a configuration known in the industry as a T flange.
[0047] The inner tower anchor bolt circle 20 has a slightly smaller diameter than the outer tower anchor bolt circle 22 . For example, the outer tower anchor bolt circle diameter may be about fourteen feet and the inner tower anchor bolt circle diameter may be about thirteen feet. A tower or other supported structure (not shown) can be attached to the concrete foundation by the tower anchor bolts 18 . Structures which can be supported on the perimeter pile anchor foundation of the present invention include, but are not limited to, transmission towers, electrical towers, communication towers, lighting standards, bridge supports, commercial signs, freeway signs, ski lift supports, solar energy towers, wind turbine towers, large stacks or chimneys, silos, tank structures, airport towers, guard towers, etc.
[0048] The tower anchor bolts 18 extend through and are nutted atop the circular tower base flange 120 at the bottom of the tower or other supported structure. The bottom ends of the bolts 18 extend to an embedment ring 32 near the bottom of the foundation. The embedment ring 32 contains bolt holes for receiving the bottom ends of each of the tower anchor bolts. The bolt ends are anchored to the ring with suitable nuts 102 and 103 or the like. The embedment ring 32 is preferably constructed of several circumferential segments lap jointed together. The embedment ring 32 is approximately the same size as and is complementary to the tower base flange 120 .
[0049] The tower anchor bolts 18 are sleeved in elongated hollow tubes, preferably PVC tubes, which cover the anchor bolts except for threaded portions at the top and bottom of the bolts. The anchor bolt sleeves prevent bonding of the bolts to the concrete 12 that is poured into the inner annular ring 72 . This sleeved structure allows the tower anchor bolts, with nuts 49 , to be elongated when post-stressed between the tower base flange 120 and the embedment ring 32 to alleviate bolt cycling and fatigue. A full description of the tower anchor bolts 18 is set forth in the '217 patent, previously incorporated herein by reference.
[0050] As shown in FIGS. 1 and 2 , the pile anchors 14 extend below the inner annular or concrete foundation ring 72 . Each pile anchor 14 includes an elongated bolt or tendon 36 , that extends through a pile anchor base plate 43 on the top surface of the foundation 10 , or preferably grouted into the top surface of the foundation, and then into a drilled pile hole 44 that is filled with pile anchor cementitious material to secure the pile anchors 14 in the ground or soil 100 . According to one embodiment, the concrete is a sand cement slurry, made with about 5 sacks of cement per cubic yard. The pile bolts 36 are on the order of 1.5 inches in diameter. Centralizers 50 are positioned at various intervals along the length of the bolts 36 to keep each bolt in the middle of its respective pile.
[0051] The embedded portion of each of the bolts 36 includes a lower end 38 that is bare, i.e., is in direct contact with the cementitious material, for bonding thereto when the cementitious material is poured or pumped to fill the interior of the drilled pile holes 44 . The cementitious material preferably fills the pile holes to their bottoms in soil 100 . An end nut 42 may be provided on the lower end of the bolt 36 to facilitate bonding of the bolt lower portion 38 with the cementitious material (see FIGS. 1 , 2 and 5 ).
[0052] If the pile bolts 36 are to be post-tensioned, the upper end of the embedded portion of the pile bolt 36 is encased in an elongated hollow tube (not shown), preferably in a plastic sleeve or the like, and most preferably by PVC tubing, to prevent bonding with the pile anchor cementitious material and to allow for post-tension stretching. This sleeved structure is fully disclosed in the '217 patent, previously incorporated by reference herein. However, according to the present invention, the pile bolts 36 do not have to be post-tensioned, in which case the sleeve is not included, as is the case shown in FIGS. 1 , 2 , 3 and 4 .
[0053] The perimeter pile foundation of the present invention is built by first drilling and then forming a plurality of individual perimeter pile anchors in a large generally circular pattern as shown in FIGS. 1 a and 6 . The pile anchors 14 are divided into a first group and a second group of piles, referred to herein as the odd and even piles, which alternate with one another around the perimeter of the foundation. The odd piles may be considered the first group or the second group, with the even piles therefore being designated whatever group the odd piles are not.
[0054] When forming the perimeter pile “circle”, the even and odd piles are preferably offset from one another so that the diameter of the circle formed by the even piles is different from the diameter of the circle formed by the odd piles as shown in FIG. 1 a . As a result, the overall perimeter formed by the odd and even piles together is not a perfect circle. Other generally circular configurations like that shown in FIG. 6 are also possible. According to the offset embodiment shown in FIG. 1 a , the difference in the diameter of the odd and even bolt circles is approximately six inches.
[0055] The individual circular pile anchors 14 are approximately 18 inches in diameter, and together form a circular pattern that is about 21 feet in diameter. As shown in FIGS. 1 a and 6 , the individual pile anchors 14 are contiguous, each pile anchor having an overlap 60 with the adjacent pile anchors on either side. As shown in FIG. 8 , the overlap 60 of the pile anchors 14 is between about one inch and about three inches. With this amount of overlap, the central bolts 36 in the pile anchors 14 that are about 18 inches in diameter are actually about 15 inches apart.
[0056] To construct the overlapping pile anchors 14 , either the odd piles or the even piles may be constructed first. For purposes of description, the odd pile anchors are formed first by drilling each odd pile hole 44 , filling the pile hole with concrete, and inserting a centralized bolt 36 vertically into the concrete to form the pile anchor 14 . The last two steps could be reversed.
[0057] The even piles are arranged in between the odd piles, with the concrete in the odd piles being allowed to preset to the stage where the concrete is firm but can still be shaved with the auger used to drill the even pile holes. The even pile holes are then drilled, filled with concrete and provided with vertically oriented centralized bolts as with the odd piles to form the even pile anchors 14 . The last two steps could be reversed.
[0058] The pile holes 44 and pile anchors 14 for the concrete foundation of the present invention can be formed in the soil below the excavation in a variety of ways and using differing equipment, depending upon the condition of the soil, as known to those skilled in the art. For example, the pile hole 44 may be simply formed by a driven mandrel or formed by a screw auger in generally stable soils. However, in unstable soils for which the perimeter pile anchor foundation of the instant application is particularly adaptable, the pile holes are preferably formed by driven pile pipes or pipes drilled, jetted or vibrated in place, such as in U.S. Pat. No. 7,533,505 which is co-owned by the applicant of this application, before positioning the pile anchor bolt, followed by the addition of the cementitious material. Alternately, the pile holes 44 may be drilled and the concrete pressure cast with hollow stemmed augers in wet sands and clays or the hole filled with the cementitious material through a tube which then serves as the anchor bolt. Other methods and equipment to form the pile anchors 14 known to those skilled in the art can be used without departing from the present invention.
[0059] Following completion and concrete set of the perimeter pile circle, the soils within the perimeter pile circle are excavated to the foundation depth 101 . As shown in FIGS. 1 and 2 , the pile anchors may extend a few feet below the intended depth of the foundation to be constructed inside the circular pattern of perimeter pile anchors. This extension of the pile anchors is not necessary, however, as the pile hole depth may be substantially the same as the foundation depth 101 .
[0060] After the pile anchors have been formed, an annular steel plate 43 formed as a ring having holes therein is placed over the piles. The centralized pile bolts 36 extend through the holes and are secured with nuts 48 to retain bolt tension. Alternatively, the ring may be formed by a plurality of individual steel plates 45 , one for each pile, with adjoining steel plates that either overlap, as in FIGS. 4 , 6 , 7 and 9 , or are spaced from one another as in FIG. 8 . Having individual steel plates provides for greater flexibility with respect to the adjoining relationship of the piles and the centralized pile bolts.
[0061] The pile anchor base plate, whether formed as a ring 43 or as independent plates 45 , is preferably grouted into the top surface of the pile anchors 14 , forming the perimeter wall 11 of the foundation 10 . This can be readily accomplished by blocking out an indentation slightly larger than the dimensions of the base plate, such as by using a Styrofoam or other easily removable form. The use of block-outs is fully discussed in the '217 patent, previously incorporated by reference. The pile anchor base plate(s) should be grouted into the top surface of the pile anchors so that the upper surface of the base plate coincides with the upper surface of the foundation 10 .
[0062] According to both configurations of the first embodiment, after the soils inside the perimeter wall 11 formed by the piles have been excavated to create area 76 as shown in FIGS. 1 and 2 , the first or outer CMP 68 is placed vertically inside the perimeter wall 11 formed by the contiguous piles 14 . Placement of the outer CMP creates the outer annular space 73 between the inside of the perimeter piles and the outer CMP. A foundation bolt cage including a plurality of vertically oriented sleeved tower anchor bolts 18 and horizontally oriented embedment ring 32 is installed vertically inside the first CMP 68 with the embedment ring 32 at the bottom. The tower anchor bolts 18 can include two bolt circles in the configuration shown in FIG. 1 , or one bolt circle in the configuration shown in FIG. 2 .
[0063] The tower anchor bolts 18 are nutted at the bottom with the embedment ring 32 with nuts 102 and nutted atop the embedment ring with nuts 103 to secure the embedment ring in place near the bottom of the concrete foundation. The tower anchor bolts are used to secure the tower to the foundation as described in the '217 patent, previously incorporated by reference herein.
[0064] The second or inner CMP 70 , having a smaller diameter than the first or outer CMP is then installed vertically inside the tower anchor bolts and the first CMP 68 . Placement of the second CMP creates the inner annular space defining the inner foundation ring 72 between the outer and inner CMPs through which the tower anchor bolts extend vertically.
[0065] A concrete plug 75 is then poured in the bottom of the inner CMP 70 , after which the area 76 inside the inner CMP atop the plug is backfilled with soil to approximately five feet below the surrounding ground surface. Alternatively, the entire area inside the inner CMP may be filled with concrete. Electrical, communication, and grounding conduits (not shown) are installed through the first and second CMPs 68 , 70 and the perimeter pile anchors 14 , and then filling of the inner CMP 70 is completed with soil to within about six inches of the top of the inner CMP 70 . Once the backfill is completed, steel welded wire mesh (WWM) atop dobies (not shown) is placed on the backfill and a capped central drain (not shown) is installed and centered into the backfill. Dobies are typically 4″ by 4″ by 2″ concrete blocks with a tie wire cast therein which is used to secure the dobies to rebar.
[0066] The inner annular space or foundation ring 72 between the outer and inner CMPs is then filled with concrete to within about three or four inches of the of the top of the CMPs to create a grout trough 130 to complete the concrete foundation ring 72 . The six inch floor area and the outer annular space 73 between the outside of the outer CMP 68 and the inside of the perimeter wall is also filled with concrete.
[0067] According to a second embodiment shown in FIG. 10 , after the pile anchors are formed, only an inner CMP 70 is vertically placed inside the pile perimeter and spaced therefrom to create an annular foundation ring 80 between the CMP 70 and the piles 14 . A direct embedded section, generally designated by reference numeral 85 , is placed near the top of the foundation ring 80 . The direct embedded section 85 includes a generally U-shaped reinforcing steel cage, generally designated by reference numeral 87 , formed by a loop of rebar coupled with a structure extension, generally designated by reference numeral 116 , which is shown in FIG. 11 . The cage 87 is constituted by a piece of rebar bent to have a generally vertical inner leg 88 and a generally vertical outer leg 89 joined at the top by a generally horizontal length 90 of the rebar extending through holes 110 in the generally cylindrical side wall 112 of the extension 116 of the embedded section 85 to form the generally U-shaped configuration for cage 87 . Rebar spacing hoops 114 are wire tied near the end of each leg to secure the legs in place in a circular configuration.
[0068] The extension 116 of the direct embedded section 85 , shown as part of the foundation in FIG. 10 and in isolation in FIG. 11 , is separate from the rebar loops which extend through the holes 110 in the extension side wall 112 . The extension 116 has a flange 95 at the top and a flange 97 at the bottom. The embedded structure extension 116 is placed between the inner leg 88 and the outer leg 89 of the cage 87 , with the extension 116 extending above the top of the concrete poured in the foundation ring 80 . The top of the flange 95 is used to connect the foundation to the tower to be supported thereon. Hence, the direct embedded section 85 takes the place of the tower anchor bolts and embedment ring that are used in the first embodiment.
[0069] The remainder of the construction of the second embodiment of the foundation is the same as that already described in connection with the first embodiment, including the pouring of a concrete plug and partial backfilling inside the inner CMP, installation of electrical, communication, and grounding conduits, completion of the backfilling of the inner CMP, placement of the steel welded wire mesh (WWM) and the capped central drain, and pouring of concrete into the annular foundation ring 80 and the floor 61 .
[0070] When constructed, both embodiments of the perimeter pile foundation result in a ring of overlapping odd and even pile anchors that form a generally circular peripheral wall, each section of which is formed as an arch. As is known in the art, forces applied to an arch structure are all resolved into compressive stresses. This is useful when building the pile anchor foundation as described herein because building materials such as concrete can strongly resist compression. The horizontal compressive forces acting on the perimeter piles hold the piles against one another in a state of equilibrium. Thus, compression and friction between adjacent piles resist soil caving and sloughing pressure when soil inside the generally circular perimeter of the piles is excavated. The large deep concrete foundation may therefore effectively be used to support a large tower 160 or other structure like that shown in FIG. 12 .
[0071] It should be understood by those skilled in the art that the foregoing description utilizes the terms “concrete” and “cementitious material” interchangeably. It will be further understood that various cementitious and cementitious-type materials can be utilized in constructing the post-tensioned pile anchor foundation of the present invention as would be utilized by those skilled in the art. These materials include, but are not limited to, sand-cement slurries, grout, and epoxy resins.
[0072] Further, while the elongated members in the pile anchors of the present invention have been described as bolts, those skilled in the art will appreciate that other elongated elements, such as strands, cables, rods, pipes, or the like, could be used in accordance with the present invention.
[0073] The foregoing descriptions and drawings should be considered as illustrative only of the principles of the invention. The invention may be configured in a variety of shapes and sizes and is not limited by the dimensions of the preferred embodiment. Numerous applications of the present invention will readily occur to those skilled in the art. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A perimeter pile anchor foundation is built by forming a plurality of individual perimeter pile anchors in a large generally circular pattern to form a perimeter wall. The individual pile anchors are contiguous, each pile overlapping the adjacent piles on either side. The overlapping pile anchors form an arch such that compression and friction between the pile anchors resist soil caving and sloughing pressure when soil inside the perimeter wall is excavated, enabling the perimeter pile foundation to be effectively constructed in weak saturated soils and/or cohesionless sands that will not allow conventional concrete foundation excavations. A concrete foundation ring is formed inside the pile perimeter wall to support a tall and/or heavy tower or other structure subject to high upset forces.
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FIELD OF THE INVENTION
This invention pertains to catheters for injecting viscous fluid into the body, and particularly to catheters that deliver viscous embolization agents into the vasculature.
BACKGROUND
Catheters have been used for decades to infuse fluids into the blood stream. For the most part, the infused fluids disperse in the blood to effectuate treatment of the patient.
The assignee of the present invention is a developer of bio-compatible agents that are particularly useful for embolization of diseased (e.g. aneurysmal) sites in the vasculature of a patient. U.S. Pat. No. 5,851,508, issued Dec. 22, 1998, describes various embolization agents. The disclosure of this U.S. patent is incorporated herein by reference. These embolization agents are typically insoluble in blood and are highly viscous to enable delivery to a particular situs in the vasculature without dispersion.
Delivery catheters used for dispensing embolization agents have been made sturdy enough to deliver the embolization agents to various parts of the vascular system. However, such catheters are often too large in diameter to effectuate treatment in the distal most reaches of the vasculature.
The diagnosis and treatment of neurovasculature disease can be of the utmost importance because neurovasculature disease (e.g. aneurysmal disease) could devastate the patient. Unfortunately, the vessels of the distal reaches of the neurovasculature are tortuous, having diameters of 3 mm, or less, and having bends exceeding 90 degrees. Tortuous vessels are difficult to reach with full-sized delivery catheters.
The amount of pressure required to dispense a viscous fluid from a small diameter tube is much greater than the pressure required to dispense the same fluid through a larger diameter tube. Accordingly, the smaller the delivery catheter, the higher the pressure required to deliver the viscous fluid.
Pressure experienced by a viscous fluid delivery catheter is normally greatest at the proximal end. The pressure decrease towards the distal end, approaching zero at the distal most tip. In testing, standard luer fittings (e.g. ISO 594-1 standard luer fittings) may fail when supplied with pressures exceeding 500 psi. Typically, a leak between the luer fitting and the catheter denotes a failure. Further, standard syringes may fail when used for pressing highly viscous fluid through catheters having relatively small diameters.
What is desired is a viscous fluid delivery system that can deliver viscous fluids to the distal reaches of the vasculature, including the neurovasculature. What is also desired is a micro-catheter that can withstand high pressures to deliver viscous fluids.
SUMMARY
A catheter for delivering viscous fluid into the vasculature of a patient includes a catheter body having a proximal end and a distal end, a reinforcing member surrounding at least a portion of the proximal end, and a compression fitting surrounding the reinforcing member for holding the proximal end of the catheter body.
The reinforcing member prevents radial compression and/or expansion of the proximal end of the catheter body, thus enabling the use of a compression fitting to hold the proximal end. The reinforcing member is tube-shaped and is either inserted within the proximal end, surrounds the proximal end, or both.
According to one aspect of the invention, the reinforcing member is integrated in the proximal end of the catheter body to resist radial deformation of the catheter body.
According to one aspect of the invention, the reinforcing member includes a tube that fully surrounds the proximal end. The tube is rigid, being fabricated from a tube of stainless steel less than 0.5″ long that bonds to the proximal end.
Preferably, the compression fitting threads into a luer fitting and thus connects the luer fitting and the proximal end in fluid communication to enable viscous fluid to be delivered via the luer fitting and through the distal end of the catheter.
A sheath covers the reinforcing member. The sheath is compressible to enable the compression fitting to squeeze the sheath and thereby grip the reinforcing tube. Preferably, the sheath is fabricated of like material as the proximal end of the catheter body and is preferably over-molded around the stainless steel tube of the reinforcing member. Accordingly, the sheath integrates the reinforcing member in the catheter body.
The catheter includes a luer fitting with threaded connectors. The compression fitting threadibly attaches the proximal end of the catheter body to the luer fitting.
According to one aspect of the invention, the compression fitting includes a locknut having a threaded outer surface and an inner surface. The inner surface defines an opening for circumscribing the reinforcing member. The outer surface of the locknut has threads. When the locknut threads into a luer fitting, for example, the inner surface presses against the proximal end and the reinforcing member of the proximal end of the catheter body. The reinforcing member thus prevents significant deformation such as a significant reduction of the inner diameter of the proximal end by the locknut.
The luer fitting includes a strain relief element that covers the compression fitting and a portion of the proximal end to inhibit radial deformation of the proximal end when a viscous fluid is delivered by the catheter. Preferably, the strain relief element attaches to the compression fitting.
Many ways of attaching the strain relief element to the catheter are possible. According to one aspect of the invention, the strain relief element attaches directly to the luer fitting. In a further aspect, the strain relief element attaches to both the luer fitting and to the compression fitting. According to another aspect of the invention, the strain relief element bonds to the compression fitting. According to another aspect of the invention, the strain relief element and the compression fitting press-fit. According to yet another aspect of the invention, the compression fitting has an annular recess that holds the strain relief element. According to still another aspect of the invention, the strain relief element bonds to both the compression fitting and to the proximal end of the catheter body.
The strain relief element tapers from the luer fitting towards the catheter body to eliminate the possibility of kinking the catheter body during normal use. The taper may assume any of a variety of configurations. Preferably, however, the taper extends between 1″-3″, and more preferably, the taper extends about 1.5″.
A system in accordance with the present invention includes the catheter and a high pressure device for delivering viscous fluid to the catheter. The high pressure device includes a syringe having a blunt needle. The needle includes a removable barb press-fit on the blunt needle. The barb is configured for piercing a vial holding viscous fluid to enable the syringe to draw the viscous fluid from the vial. The barb slides off of the needle when the needle is removed from the vial.
A method of filling a syringe with viscous fluid in accordance with the present invention includes providing a syringe having a needle and a vial of viscous fluid, press fitting a removable barb on the blunt needle, piercing the vial with the barb, drawing viscous fluid into the syringe from the vial, and removing the needle from the vial and thereby causing barb to slide off of the needle so that the barb remains in the vial. Another step in accordance with this method includes inserting the needle into a catheter and delivering the viscous fluid to the neurovasculature of a patient via the catheter.
The dimensions of the catheter body are preferably adapted for accessing the distal and tortuous reaches of the neurovasculature. Accordingly, the distal end has an outside diameter of 0.040″ or less to facilitate insertion of the catheter into tortuous regions of the vasculature. More preferably, the distal end has an outside diameter of less than 0.029″.
The distal end further includes a delivery lumen with lumen walls. The lumen walls being at least 0.0012″ thick to withstand pressures associated with the delivery of a viscous fluid. The proximal end of the catheter body being configured for attachment to a luer fitting and for withstanding pressures exceeding 2000 psi. Also, the syringe, the luer fitting and medial portions of the catheter body are also configured for withstanding pressures of 2000 psi or more.
The syringe attaches to the luer fitting with a syringe locknut. The syringe needle inserts into the syringe locknut and the syringe locknut to holds the needle when the syringe locknut threads into the luer fitting.
According to one aspect of the luer fitting, the luer fitting is bifurcated, having a three threaded portions to simultaneously receive and attach two syringes to two of the threaded portions, and to attach the compression fitting and the catheter body to the remaining threaded portion, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a catheter in accordance with the present invention.
FIG. 2 is an exploded view of the catheter of FIG. 1 shown partly in cross-section.
FIG. 3 is a cross-section of the proximal end of a catheter body in accordance with the present invention.
FIG. 4 is a cross-section of the distal end of a catheter body in accordance with the present invention.
FIG. 5 is a shows a syringe inserted into a vial of viscous fluid.
FIG. 6 shows the syringe of FIG. 5 withdrawn from the vial.
FIG. 7 shows an alternate embodiment of a luer fitting in accordance with the present invention.
DETAILED DESCRIPTION
FIG. 1 shows a catheter generally designated with the reference numeral 10 . The catheter 10 includes a catheter body 12 with a proximal end 14 and a distal end 16 . The catheter 10 also includes a luer fitting 18 with a compression fitting 20 and a strain relief element 22 . The compression fitting 20 attaches the proximal end 14 of the catheter body to the luer fitting 18 .
The catheter 10 has a syringe 24 with a needle 26 inserted into the luer fitting 18 . The syringe 24 includes a syringe locknut 30 that removably attaches the luer fitting 18 to the syringe 24 in fluid communication. The syringe 24 is capable of delivering viscous fluid under pressures of at least between 1000 psi and 2000 psi.
The catheter 10 is particularly designed for delivering viscous fluids at high pressures to within the body of a patient. While the catheter 10 can be used within the digestive track, and in various internal tissues and organs, the primary use for the catheter 10 is to deliver embolization agents to address aneurysmal disease. Accordingly, the catheter 10 is sized for use in tortuous regions of the vasculature in order to reach the distal reaches of the neural vasculature, where aneurysmal disease can have great impact.
Commonly assigned U.S. Pat. Nos. 5,667,767, 5,580,568, 5,830,178, and 6,051,607 describe various embolization agents including cellulose diacetate compositions, dimethylsulfoxide compositions, and Ethyl Lactate compositions, having relatively high viscosity, that are injectable in a viscous fluid form into a diseased or injured portion of the vasculature to improve the blood vessel integrity. The disclosures of these U.S. patents are incorporated herein by reference.
Some of these embolization agents, and others, have been successfully used to fill aneurysms, thereby structurally strengthening the blood vessel. Methods of embolizing blood vessels are described in commonly assigned U.S. Pat. Nos. 5,702,361 and 6,017,977, the disclosures of which are incorporated herein by reference.
During a vascular application, the viscous embolization agent typically injects via a vascular catheter without dispersion in the blood. The viscous embolization agent sets over a period to structurally strengthen the blood vessel.
While it can be appreciated that embolization agents are used in the vasculature, there are many other applications for such embolization agents such as to treat urinary incontinence, to facilitate plastic surgery, to treat ruptured spinal disks, gynecologic dysfunction, treating endoleaks, etc. The present invention can be applied to these applications, and more. Further, while the catheter 10 disclosed herein is used to inject the agents is typically a vascular catheter, the geometry and integrity of the catheter 10 can be particularly adapted to address virtually any site within the body. The catheter 10 is useful for dispersing both dispersable and non-dispersable embolization agents.
The luer fitting 18 has two ends 32 and 34 . Both of the ends 32 and 34 have internal threads. The end 34 is threaded for receiving the compression fitting 20 . The end 32 receives either an introducer locknut that is sized in accordance with ISO 594-1, or a syringe locknut 30 . An introducer locknut of standard configuration is used prior to attachment of the high pressure syringe for introduction of a guidewire, contrast agent, saline, medicine or any other adapter requiring an ISO 594-1 standard luer fitting connection.
The syringe locknut 30 that holds the needle 26 of the syringe 24 in the end 32 . Removal of the syringe locknut 30 , and the syringe 24 , enables alternate attachment of a second syringe to the end 32 of the luer fitting 18 .
The proximal end 14 of the catheter body 12 attaches to the end 34 of the luer fitting to enable the luer fitting 18 and the proximal end 14 of the catheter body 12 to withstand operational pressure exceeding 2000 psi. The compression fitting 20 attaches the proximal end 14 of the catheter body to the luer fitting 18 . The compression fitting 20 enables the luer fitting 18 and the proximal end 14 of the catheter body 12 to withstand high operational pressures.
The distal end 16 of the catheter body 12 includes marker bands 28 to enable an operator to locate the distal end 16 during use. The distal end 16 is particularly configured for accessing tortuous regions of the neurovasculature. Tortuous regions are defined as those vascular regions having bend exceeding 90 degrees and having a vascular diameter of 3 mm or less. Accordingly the distal end 16 has an outside diameter of 0.040″ or less. The distal end includes a delivery lumen with lumen walls, the lumen walls being at least 0.0012″ thick to withstand pressures associated with the delivery of viscous fluids.
FIG. 2 shows the syringe 24 , the syringe locknut 30 , the luer fitting 18 , the compression fitting 20 , the catheter body 12 and the strain relief element 22 . The syringe locknut 30 is one form of compression fitting. There are other compression fittings, however, including compression fittings formed from thermal bonding techniques, insert-moldings and over-moldings, for examples. These alternate forms of compression fittings can be substituted for the syringe locknut 30 in accordance with the present invention.
The syringe locknut 30 is hollow, having a centrally defined opening 33 for receiving the needle 26 of the syringe 24 . The syringe locknut 30 compresses against the needle 26 to hold and seal the needle 26 .
The syringe locknut 30 includes a threaded portion 31 and an angled section 37 . The syringe locknut 30 rotates to thread the threaded portion 31 to the end 32 of the luer fitting 18 . When the needle 26 inserts into the luer fitting 18 , and the syringe locknut 30 slide forward in place with respect to the luer fitting 18 and rotates, the needle 26 does not significantly deform, instead, the angled section 37 of the syringe locknut 30 radially compresses to hold the needle 26 within the opening 33 .
The compression fitting 20 , according to one aspect of the invention, is a locknut that radially compresses to hold the proximal end 14 of the catheter body 12 when threaded to the luer fitting 18 . The compression fitting 20 includes an opening 35 axially defined in the compression fitting 20 . When the proximal end 14 of the catheter body 12 inserts into the opening 35 , and the compression fitting 20 rotates to thread into the end 34 of the luer fitting 18 , then the compression fitting radially compresses against the proximal end 14 of the catheter body 12 .
In order to allow the compression fitting to hold the proximal end 14 of the catheter body, the proximal end 14 has a rigid tip 39 that resists radial compression.
The compression fitting 20 includes an annular recess that holds the strain relief element 22 . The strain relief element 22 thus attaches to the luer fitting 18 . It can be appreciated, however, that there are many ways to attach the strain relief element 22 to the luer fitting 18 .
The strain relief element 22 includes a length “l”. A portion of the length “l” has a taper “t”. The taper “t” extends in a direction from the luer fitting towards the catheter body 12 to support the proximal end 14 of the catheter body 12 . Preferably, the taper extends between 1″-3″, and more preferably the taper extends about 1.5″.
The strain relief element 22 is soft to support proximal end 14 and to allow flexibility of the proximal end 14 , while minimizing any potential for kinking of the proximal end 14 .
FIG. 3 shows the rigid tip 39 of the catheter body 12 . The rigid tip 39 includes a portion of the proximal end 14 , a reinforcing member 38 and a sheath 40 . The reinforcing member 38 surrounds at least a portion of the proximal end 14 to inhibit radial deformation. The sheath 40 surrounds the reinforcing member 38 .
According to an alternate aspect of the invention, the reinforcing member 38 is sized to insert into the proximal end 14 to inhibit radial deformation. According to a further aspect of the invention, the reinforcing member is undermolded in place with respect to the proximal end 14 .
The reinforcing member 38 is preferably a band of stainless steel that circumscribes the proximal end 14 to enable the proximal end 14 to resist deformation caused by the compression fitting 20 (FIG. 2 ). The reinforcing member 38 also prevents radial expansion of the proximal end 14 . Preferably the reinforcing member 38 has a length that does not exceed a length of the compression fitting 20 . However, it can be appreciated that the length can be modified if operating pressures require the proximal end 14 to have additional reinforcement.
FIG. 4 shows the marker bands 28 circumscribing the distal end 16 of the catheter body 12 . The catheter body 12 is hollow, defining a viscous fluid delivery lumen 56 . The catheter body has an outside diameter 58 of 0.040″ or less to facilitate insertion of the distal end 16 into tortuous regions of the vasculature. The distal end 16 includes lumen walls 60 . The lumen walls 60 are at least 0.0012″ thick to withstand pressures associated with delivery of viscous fluid. Preferably, the delivery lumen 56 has an inside diameter of 0.025″ or less. For some applications, the delivery lumen 56 is adapted to have an inside diameter of less than 0.005″.
FIG. 5 shows the syringe 24 having a barb 44 with a sharpened tip 52 attached to the needle 26 in a friction fit around the needle 26 . The syringe 24 inserts into a vial 46 of viscous fluid 48 in the direction of the arrow 42 .
The syringe 24 includes a blunt needle 26 . The barb 44 is removable and press-fits on to the needle 26 . The vial 46 has a cap 50 .
A method of filling the syringe 24 with viscous fluid 48 includes press-fitting the removable barb 44 on the blunt needle 26 . The next step includes piercing the cap 50 of the vial 46 with the tip 52 of the barb 44 . Further inserting the barb 44 and the needle 26 enables access to the viscous fluid 48 . The syringe draws the viscous fluid 48 via the needle 26 from the vial 46 and into the syringe 24 . Although a syringe 24 is used to withdraw the viscous fluid 48 , it can be appreciated that other mechanisms can withdraw fluid from a vial.
FIG. 6 shows the syringe 24 and needle 26 removing from the vial 46 . The cap 50 remains fixed on the vial 46 . Withdrawal of the syringe in the direction of the arrow 54 causes the barb 44 to slide off the needle 26 . The barb 44 remains in the vial 46 . Accordingly, movement of the syringe 24 and the integrity of the cap cooperate to cause the barb 44 to slide off of the needle 26 .
Once the syringe 24 is filled with viscous fluid 48 , the needle 26 is inserted into the luer fitting 18 (FIG. 1) for delivering the viscous fluid to a patient via the catheter.
FIG. 7 shows an embodiment of the luer 18 having a bifurcated design. The luer fitting 18 has three of threaded portions 62 , 64 and 68 . The threaded portion 68 attaches to the compression fitting 20 . The threaded portions 62 and 64 attach, respectively to fluid delivery systems such as syringes.
While the present invention is described in terms of particular embodiments shown in the drawings, there are various ways to design, assemble and use the invention which may depart from the exemplary description provided herein. Accordingly, the claims should be limited only by the claims as set forth below.
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A catheter and system for delivering viscous fluid, under high pressures, into the vasculature of a patient includes a catheter body having a proximal end and a distal end, a reinforcing member surrounding at least a portion of the proximal end, and a compression fitting surrounding the reinforcing member for holding the proximal end of the catheter body. A strain relief element shrouds a portion of the proximal end to prevent kinking of the catheter body. Accordingly, the reinforcing member, the compression fitting and the strain relief element cooperate to hold the catheter body in a luer fitting and to prevent the proximal end of the catheter body from kinking under bending, and to prevent leakage or bursting under pressure.
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BACKGROUND OF THE INVENTION
The present invention relates to the fabrication of semiconductor devices. More particularly, the present invention relates to improved techniques for fabricating electrically blowable fuses on a semiconductor substrate.
Fuses have long been employed in integrated circuits. A fuse typically comprises a fuse portion formed of a fuse material that may be turned into a non-conductive state through various mechanisms. When the fuse is in its conductive state, an electrical current may pass through the fuse portion. When the fuse is blown, i.e., becomes non-conductive, an open circuit is created through which very little, if any, current may pass.
Exemplary uses of fuses include, for example, protecting sensitive portions of the integrated circuit during manufacturing to prevent a build up of charge from damaging the sensitive electronic devices thereon. After the integrated circuit is manufactured, the fuse may be blown to sever the current path, and the resulting IC may be employed as if the current path never existed. Fuses may also be employed to, for example, set the address bits of a redundant element in a dynamic random access memory (DRAM) array in order to specify to the decoding circuit the address of the defective main memory array element. With the address information furnished by the fuses, the redundant element may then be employed to replace the defective main memory array element.
Although there are many fuse designs today, two types of fuses have received wide acceptance: laser blowable fuses and electrically blowable fuses. With laser blowable fuses, the fuses are typically formed at or near the surface of the integrated circuit. A laser beam striking the fuse material renders the fuse portion non-conductive, thereby inhibiting current from flowing through. Although laser blowable fuses are relatively simple to fabricate, there are disadvantages. For example, the laser blowable fuses tend to be surface oriented, which places a limitation on the design of the IC. Further, laser blowable fuses tend to occupy a large amount of space on the IC surface since the adjacent fuses or devices must not be placed too close to the fuse or risk being inadvertently damaged by the laser beam during the fuse setting operation.
Electrically blowable fuses, on the other hand, do not have to be placed at or near the surface of the integrated circuit. Accordingly, they give the designers greater latitude in fuse placement. In general, they tend to be smaller than laser blowable fuses, which render them highly suitable for use in modern high density integrated circuits.
In a typically electrically blowable fuse, the fuse portion, typically formed of a material that changes its state from conductive to non-conductive when a current exceeding a predefined threshold is passed through, is typically disposed in a dielectric microcavity, i.e., a sealed, hollow chamber in a dielectric layer. The microcavity itself is typically formed in a multistep process, which conventionally requires one or more photolithography steps in the prior art.
To facilitate discussion, FIGS. 1 and 2 illustrate the prior art process for forming an electrically blowable fuse. Referring initially to FIG. 1, a fuse portion 102 is shown disposed on a substrate 104. Fuse portion 102 typically comprises a conductor made of a suitable fuse material such as doped polysilicon or metal. For reasons which will become apparent shortly, the fuse portion is typically capped with a silicon nitride layer.
As mentioned, fuse portion 102 is dimensioned and configured such that when a current exceeding a predefined current value passes through fuse portion 102, it changes to a non-conductive state to essentially inhibit current from subsequently flowing through. Substrate 104 typically represents an oxide layer and may include any other structures of the integrated circuit. By way of example and not by way of limitation, substrate 104 may represent a gate oxide or even any oxide layer above a shallow trench isolation (STI) area. Above fuse portion 102, another oxide layer 106 is conformally deposited. A silicon nitride layer 108 is then deposited above oxide layer 106.
Above silicon nitride layer 108, a photoresist layer 110 is deposited and patterned to form an opening 112. Patterned photoresist mask 110 is then employed to etch through silicon nitride layer 108 to expose a portion of oxide layer 106 above fuse portion 102. After an opening in silicon nitride layer 108 is formed, a subsequent isotropic etch is performed to create the microcavity. As is apparent, silicon nitride layer 108 acts as a hard mask during the isotropic etch of microcavity 202.
In FIG. 2, microcavity 202 has been isotropically etched out of oxide layer 106 through the opening in silicon nitride layer 108. The microcavity etch preferably employs an etch process that is selective both to the liner material of fuse portion 102 and silicon nitride layer 108.
Subsequent to the formation of microcavity 202, a plug layer 206, e.g., another oxide layer, is then deposited. The deposition process that forms plug layer 206 is such that the opening in the silicon nitride layer is sealed with the plug material while microcavity 202 is left hollow. Thus fuse portion 102 is essentially sealed within microcavity 202 after the deposition of plug layer 206. Accordingly, any particulate material that may be formed when fuse portion 102 is blown is kept contained within microcavity 202, thereby minimizing or essentially eliminating any possibility of particulate contamination of the IC surface.
It has been found, however, that the conventional process of forming electrically blowable fuse 100 has some disadvantages. In particular, the prior art technique of forming electrically blowable fuses requires at least one photolithography step to pattern a hard mask out of silicon nitride layer 108. As is known by those skilled in the art, photolithography is an expensive process and is therefore generally undesirable from a cost standpoint. Further, as the density of the integrated circuit increases and its feature sizes decrease, accurate alignment becomes problematic. By way of example, as fuse portion 102 decreases in width and the adjacent fuses and/or devices are packed closer together, the accurate alignment of opening 112 in photoresist layer 110 with fuse portion 102 becomes increasingly difficult. These and other challenges presented by the photolithography step render the fabrication of electrically blowable fuses 100 unduly expensive and, in many cases, even prohibitively expensive.
In view of the foregoing, there are desired improved techniques for fabricating electrically blowable fuses. In particular, there are desired improved techniques for forming electrically blowable fuses that do not require the use of a photolithography step to form a hard mask for the subsequent microcavity etch.
SUMMARY OF THE INVENTION
The invention relates, in one embodiment to a method for fabricating an electrically blowable fuse on a semiconductor substrate. The method includes forming a fuse portion on the semiconductor substrate. The fuse portion is configured to turn substantially non-conductive when a current exceeding a predefined current level passes through the fuse portion. The method also includes depositing a substantially conformal first layer of dielectric material above the fuse portion and depositing a second layer of dielectric material above the first layer, thereby forming a protrusion of dielectric material above the fuse portion. The second layer is different from the first layer.
The method further includes performing chemical-mechanical polish on the protrusion to form an opening through the second layer above the protrusion. There is also included etching, in a substantially isotropic manner, a portion of the first layer through the opening to form a microcavity about the fuse portion. The etching is substantially selective to the second layer and the fuse portion. Additionally, there is included depositing a substantially conformal third layer of dielectric material above the second layer, thereby closing the opening in the second layer.
In another embodiment, the invention relates to a method for fabricating an electrically blowable fuse on a semiconductor substrate. The method includes providing the substrate having thereon a protrusion of dielectric material comprising a first layer of dielectric material and a second layer of dielectric material above a fuse portion. The fuse portion is configured to change to a substantially non-conductive state when a first electrical current is passed through the fuse portion. The first layer represents a substantially conformal layer of first dielectric material above the fuse portion while the second layer represents a substantially conformal layer of second dielectric material above the first layer. The second dielectric material is different from the first dielectric material.
The method also includes performing chemical-mechanical polish on the protrusion to form an opening through the second layer above the protrusion, thereby exposing the second layer through the opening. The opening is configured to facilitate a subsequent etching of a portion of the first layer through the opening to form a microcavity about the fuse portion. The etching is substantially selective to the second layer and the fuse portion.
These and other features of the present invention will be described in more detail below in the detailed description of the invention and in conjunction with the following figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIGS. 1 and 2 illustrate, to facilitate discussion, the conventional prior art technique for forming an electrically blowable fuse on an IC.
FIGS. 3, 4, 5, and 6 illustrate, in accordance with one aspect of the present invention, the improved technique for forming an electrically blowable fuse on an IC.
FIG. 7 illustrate, in accordance with one aspect of the present invention, the steps for forming the electrically blowable fuse of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described in detail with reference to a few embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, 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 steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention.
In one embodiment, there are provided techniques for forming electrically blowable fuses used in an ICs. Such IC includes a random access memory (RAM), a dynamic random access memory (DRAM), a synchronous DRAM (SDRAM), and a read only memory (ROM). Other types of ICs include application specific integrated circuits (ASICs) or any logic circuit. Typically, a plurality of ICs are formed on the wafer in parallel. After processing is finish, the wafer is diced to separate the ICs to individual chips. The chips are then packaged, resulting in a final product that is used in, for example, consumer products such as computer systems, cellular phones, personal digital assistants (PDAs), and other electronic products. The electrically blowable fuses are formed without requiring the use of a photolithography step to create a hard mask for the subsequent microcavity etch. In one embodiment, the opening in the hard mask is achieved by abrading or polishing through the hard mask layer using a relatively short chemical-mechanical polish (CMP) step.
The invention takes advantage of the intrinsic tendency of the CMP process for attacking isolated high spots on the substrate surface to solve the alignment problem, i.e., the alignment of the hard mask opening with the underlying fuse portion. It is advantageously recognized that since the high spots or protrusions are formed above the fuse portion through the use of conformal dielectric layer deposition, the CMP process automatically aligns the abraded spot, i.e., the opening in the vicinity of the high spot, with the underlying fuse portion. Once the opening is created, a subsequent microcavity etch may be employed to create the microcavity for the fuse.
The features and advantages of the invention may be better understood with reference to the Figures that follow. FIGS. 3, 4, 5, and 6 illustrate, in accordance with one aspect of the present invention, the improved technique for forming electrically blowable fuses. As in FIGS. 1 and 2, a fuse portion 102 is again shown disposed above substrate 104 in FIG. 3. As mentioned earlier, fuse portion 102 preferably comprises a conductor formed of an appropriate fuse material such as polysilicon or metal. Polysilicon is preferred, in some applications, as the fuse material since it may offer a greater thermal budget. In one embodiment, fuse portion 102 may be employed to protect the gate structures of transistors and may therefore be formed from the same layers that are used to form the gates of transistors. In some of these applications, a layer of tungsten silicide or titanium silicide may cover the layer of fuse material. A silicon nitride liner may be provided to encapsulate and protect fuse portion 102 from being attacked in the subsequent microcavity etch. In one exemplary application, the fuse structure may be about 5,000-6,000 angstroms thick.
Above fuse portion 102 and substrate 104, a first dielectric layer 302 is conformally deposited. In one exemplary application, first dielectric layer 302 may be about 8,000-9,000 angstroms thick. First dielectric layer 302 may be formed of any suitable dielectric material that may be conformally deposited over fuse portion 102 and substrate 104. In one embodiment, first dielectric layer 302 represents a layer of borophosphosilicate (BPSG) glass. First dielectric layer 302 may also be a layer of phosphorous doped silicate glass (PSG) or phosphorous doped high density oxide (PHDP-oxide). First dielectric layer 302 may in fact be any doped oxide layer or any type of suitable conformal dielectric material. In one particularly advantageous embodiment, the first dielectric layer represents a layer of glass deposited by a conventional high density plasma process. As the term is employed herein, high density plasma deposition refers to the deposition of materials in a low pressure plasma CVD chamber that employs not only a source but also bias power to permit simultaneous deposition and sputtering. The high density plasma film conformally covers fuse portion 102 while substantially planarizing smaller, more tightly spaced features on the IC.
Above first dielectric layer 302, a second dielectric layer 304 is deposited. The thickness of the second dielectric layer is sufficient to serve as an etch mask for the subsequent etch that forms a microcavity within first dielectric layer 302. The thickness of the second dielectric layer 304 may be about 1,000 angstroms. The second dielectric layer 304 comprises a material that the first dielectric layer can be etched selectively thereto. That is, the etch effectively removes the first dielectric layer without removing the second dielectric layer. In one embodiment, the second dielectric layer 304 comprises silicon nitride. Other suitable dielectric material which the first dielectric layer can be etched selectively thereto may also be employed.
Illustratively, the second dielectric layer is conformally deposited over the first dielectric layer. As such, the topography of the underlying layer is reflected in the deposited layer, resulting in a protrusion on the surface of the substrate. Because of the underlying fuse portion, the protrusion is formed directly above fused portion 102, as shown in FIG. 3. A non-conformally deposited second dielectric layer is also useful. When a non-conformal layer is deposited, the topography of the underlying layer is not reflected therein.
In FIG. 4, a chemical mechanical polish (CMP) step is employed to polish or abrade the protrusion above fuse portion 102 to break through second dielectric layer 304 and expose a portion of first dielectric layer 302 to the subsequent microcavity etch. The opening in second dielectric layer 304 is shown in FIG. 4 as opening 408. The invention employs, in one embodiment, the first dielectric layer 302 as a CMP stop layer. In other words, the CMP process stops as soon as or shortly after the underlying first dielectric layer 302 is exposed. In general, the CMP step may be relatively short, which tends to improve throughput, e.g. about 10-60 seconds in some cases. As can be appreciated by those skilled in the art, the CMP step is employed, in a nonobvious manner, in the formation of the hard mask that is employed to subsequently etch the microcavity in the first dielectric layer 302. In embodiments employing a non-conformal second dielectric layer, the CMP time may be increased since more material may need to be removed before exposing the underlying first dielectric layer.
In FIG. 5, a microcavity has been etched in first dielectric layer 302 through opening 408 in hard mask/second dielectric layer 304. The microcavity etch step is preferably designed such that it does not unduly attack second dielectric layer 304 and fuse portion 102. As second dielectric layer 304 and the protective liner encapsulating fuse portion 102 are made of a silicon nitride material in one embodiment, the microcavity etch preferably employs an etchant that does not unduly attack silicon nitride. In one embodiment, an wet (e.g., isotropic) HF etch works well for a BPSG first dielectric layer 302. However, isotropic etching is not a requirement and etching may be performed in a somewhat anisotropic manner as long as such etching results in a microcavity that is capable of being subsequently sealed.
In FIG. 6, a third dielectric layer 606 is deposited above second dielectric layer 304. Third dielectric layer 606 may, for example, represent a low pressure chemical vapor deposition oxide layer (LPCVD) or LPCVD TEOS. Third dielectric layer 606 represents a plug dielectric layer, whose deposition process is configured to seal opening 408 in second dielectric layer 304 without filling microcavity 502 with dielectric material, thereby sealing microcavity 502 from the rest of the integrated circuit. When fuse portion 102 is blown, any particulate material that is generated is advantageously kept within microcavity 502, thereby minimizing or substantially eliminating particulate contamination problems during the fuse setting process.
FIG. 7 illustrates, in accordance with one embodiment of the present invention, the steps employed in the formation of a typical electrically blowable fuse. In step 702, a substrate is provided. As mentioned, the substrate may represent a silicon substrate on which devices have already been formed. In step 704, a fuse portion, e.g., a conductor formed of a fuse material, is formed. In steps 706 and 708, the first and second dielectric layers are conformally deposited. In step 710, a CMP step is employed to polish through the second dielectric layer at the protruded spot to expose a portion of the underlying first dielectric layer. In step 712, a microcavity etch step is employed to etch a microcavity in the first dielectric layer through the opening in the hard mask/second dielectric layer while leaving the hard mask and the fuse portion substantially unetched. In step 714, a third dielectric layer representing a plug layer is deposited to close up the opening in the hard mask/second dielectric layer, thereby sealing the microcavity from the outside.
As can be appreciated from the foregoing, the photolithography step employed in the prior art to form a hard mask out of second dielectric layer 304 has been eliminated. Accordingly, the high cost and alignment problems associated with the photolithography step are also advantageously eliminated. In a nonobvious manner, the present invention employs chemical mechanical polish (CMP) as a mask forming technique. The use of CMP as a mask forming technique is nonobvious since CMP is typically regarded as a planarizing step, i.e., not as a step to form selective, aligned openings in a layer. Further, it would be nonobvious to employ CMP to form a hard mask since CMP is generally not favored by process engineers since the CMP material removal depth tends to be difficult to control and scratches may form on the substrate if the CMP process is not carefully designed. The use of a CMP step is also nonobvious since CMP tends to generate particulate matter (in the form of a slurry), which requires subsequent cleaning steps and is therefore generally undesired by process engineers. Further, most fabrication facilities do not have CMP tools. Accordingly, most process engineers would not naturally think of CMN as a process to create a hard mask.
Further, the invention takes advantage of the intrinsic nature of the CMP process to attack high spots or protrusions on the substrate surface to automatically align the opening of the hard mask with the underlying fuse portion. Because of this, microcavity 502 is correctly positioned about fuse portion 102 in a subsequent microcavity etch step.
In accordance with another aspect of the present invention, the CMP step may be performed using a soft pad, i.e., a pad that can locally "adapt" to the underlying topography to ensure that the CMP step removes only the protrusions or high spots above the fuse portions without inadvertently removing the dielectric material from other raised portions of the integrated circuit. Alternatively or additionally, supplemental design rules may be specified to prevent the inadvertent removal of the dielectric material from other raised portions of the integrated circuit. To ensure protection of raised areas where CMP removal is not desired, the electrically blowable fuses may be positioned away from other structures of the IC. Alternatively or additionally, dummy structures may be put around structures which need to be protected from CMP. These additional dummy structures form raised plateaus instead of isolated raised protrusions or high spots, which tend to be more readily attacked by the CMP process.
While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents which fall within the scope of this invention. By way of example, although the disclosures refers mainly to DRAMS, the fuses formed in accordance with the techniques disclosed herein may be employed in any fuse application on any type of IC, e.g., to protect sensitive components and/or provide binary values. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention.
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A method for fabricating an electrically blowable fuse on a semiconductor substrate. The method includes forming a fuse portion 102 on the semiconductor substrate. The fuse portion is configured to turn substantially non-conductive when a current exceeding a predefined current level passes through the fuse portion. The method also includes depositing a substantially conformal first layer 302 of dielectric material above the fuse portion and depositing a second layer 304 of dielectric material above the first layer, thereby forming a protrusion of dielectric material above the fuse portion. The second layer being different from the first layer. The method further includes performing chemical-mechanical polish on the protrusion to form an opening through the second layer above the protrusion. There is also included etching, in a substantially isotropic manner, a portion of the first layer through the opening to form a microcavity 502 about the fuse portion. The etching is substantially selective to the second layer and the fuse portion. Additionally, there is included depositing a substantially conformal third layer 606 of dielectric material above the second layer, thereby closing the opening in the second layer.
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FIELD OF THE INVENTION
This invention relates generally to valves for controlling the flow of fluids and especially to valves that incorporate packing assemblies for establishing a fluid tight seal between a valve body structure and a valve stem for controlling an internal valve element. More specifically, the present invention relates to a packing assembly for valves having the capability of withstanding high temperatures such as might be caused when the valve mechanism is subjected to extreme heat, for example, in case of fires.
BACKGROUND OF THE INVENTION
Virtually all valves for controlling the flow of fluids in piping systems comprise a valve body structure having a valve element therein that is capable of being moved between open and closed positions. In most cases, the valve is provided with a valve stem that extends through the valve body and is connected to the internal valve element. In order to prevent leakage between the valve stem and valve body, the valve mechanism is typically provided with a stem packing assembly that is received within a packing chamber or stuffing box and which encircles the valve stem. Packing assemblies may develop sealing characteristics responsive to application of mechanical pressure thereto or, in the alternative, application of fluid pressure thereto may enhance the sealing capability of such packing assemblies.
Most packing assemblies for valves incorporate sealing materials such as rubber or rubber-like material, plastic, and in many cases lubricant materials. The function of the packing assembly is to completely fill the space between the valve actuator stem and valve body structure to thus prevent liquid or gaseous materials from escaping through the valve stem opening of the valve. The packing assembly must also allow movement of the valve stem, either linearly in the case of gate valves, rotatably in the case of plug valves, and in some cases both linearly and rotatably in the case of lift turn plug valves. Most packing assemblies that are available at the present time, have the capability of achieving adequate sealing capability while at the same time allowing the valve stem freedom of movement for the purpose of valve actuation.
In the petroleum and petrochemical industries, flow lines often transport flammable material that will feed a fire that has become ignited. Where valves are employed to control the flow of such hazardous fluids, it is highly desirable that at least some of the valves have the capability of maintaining effective sealing even under circumstances where the piping system and valve is subjected to extreme external heat such as typically occurs when a fire has become ignited. In most cases, the packing assemblies of valves are incapable of withstanding extreme heat and the sealing materials deteriorate rapidly, thereby allowing leakage past the valve stem packing. Under circumstances where the flow system is maintained under significantly high pressure, the flammable or otherwise hazardous liquid will leak past the packing at a significantly high rate to feed the fire. This is detrimental to fire fighting and to the safety of personnel in the immediate vicinity. If some of the valves of the flow system are provided with packing assemblies that are effectively resistant to extremely high temperatures, these valves may be positioned in the open or closed positions thereof as desired for purposes of efficiency in fighting the fire and for the purposes of safety to personnel. Since the valve stem packing will maintain its sealing capability even when heated to an extremely high temperature, the flammable fluid of the flow line will be effectively controlled at least for a sufficient period of time to allow the fire to be brought under control.
THE PRIOR ART
The problem of valve leakage at high temperatures has been subjected to considerable study in the past and various developments have been made with the view toward provision of a valve packing assembly having the capability of withstanding high temperatures. Graphite is a material that is widely used where high temperatures are concerned because of its capability of effective temperature resistance. For example, U.S. Pat. Nos. 4,006,881 of Gaillard; 4,160,551 of Nixon, et al and 4,190,257 of Schnitzler disclose various valve stem packing materials composed of or including graphite or other such carbonaceous materials. One recent development for high temperature valve stem packing materials, pump seals, etc. is a graphite tape material such as that sold under the registered trademark "GRAFOIL" by Union Carbide Corporation, New York, N.Y. High temperature valve stem packings composed of graphite tape are evidenced by U.S. Pat. Nos. 4,068,853 of Schnitzler, 4,090,719 of Simanskis, et al, and 4,157,835 of Kahle, et al. Also of interest to this invention is U.S. Pat. No. 4,116,451 of Nixon, et al which discloses seal rings incorporating low-friction graphite having a ring of V-shaped spring metal imbedded therein. U.S. Pat. No. 3,512,787 of Kennedy, et al discloses a floating seal packing assembly having spring means to maintain the packing assembly under mechanical compression. U.S. Pat. No. 3,013,830 of Milligan discloses a packing assembly incorporating V-shaped sealing members and packing adapter rings having concave and convex seal engaging surfaces.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a packing assembly for valves having the capability of withstanding extremely high temperatures and maintaining an effective seal at such high temperatures.
It is also a feature of this invention to provide a novel high temperature packing assembly for valves wherein the packing assembly is capable of pressure energization as well as mechanical energization even under high temperature conditions.
It is an even further feature of this invention to provide a novel high temperature packing assembly for valves incorporating graphite seal rings which are effectively capable of being deformed so as to present a concave surface thereof in an upstream direction in regard to pressure.
Among the several objects and features of this invention is contemplated the provision of a novel valve stem packing assembly having the capability of withstanding high temperatures and which is composed at least partially of a plurality of graphite seal rings formed by helically wound graphite tape and deformed endwise to present concave surfaces thereof in an upstream direction in respect to pressure.
It is an even further feature of this invention to provide a novel high temperature valve stem packing assembly incorporating metal packing adapters located between graphite seal rings and having the function of forming the surfaces of adjacent graphite seal rings so as to selectively define concave, planer and convex surfaces at desired portions of the seal rings.
It is also a feature of this invention to provide a novel valve stem packing assembly having packing rings that are capable of yielding in spring-like nature and which also function to form particular surface contours on graphite seal rings in contact therewith.
Briefly, the present invention concerns a valve stem packing assembly which utilizes as the basic sealing components thereof a plurality of graphite seal rings. Each of the graphite seal rings is composed of helically wound graphite tape, thus developing a circular mass of graphite material of sufficient dimension to be received in close fitting relation within a packing chamber or stuffing box defined between the valve stem and valve body structure. Interposed between the graphite seal rings are intermediate packing adapter rings that are also dimensioned to be received in the annular packing chamber or stuffing box of the valve. Each of the intermediate packing adapter rings is formed to define a generally planar surface at the end thereof facing upstream and also defines a circular surface having a convex cross-sectional configuration which deforms the engaging end surfaces of the graphite seal rings to a corresponding circular concave configuration. The packing assembly also incorporates adapter rings that are positioned at the respective ends of the packing assembly. One of these end adapter rings defines a generally planar circular surface that is directed upstream in respect to pressure. This same packing ring also defines a circular convex surface at the opposite end thereof which engages one of the graphite seal rings and forms an end surface of that seal ring to a corresponding concave configuration. At the opposite extremity of the packing assembly is provided an end adapter ring defining a circular concave surface directed upstream toward pressure and being in surface forming contact with one of the graphite seal rings. The opposite end surface of the end adapter ring is of generally planar configuration and is adapted to be engaged by means of a packing retainer that is bolted or otherwise fixed to the valve body structure and secures the packing assembly in its proper position within the packing chamber.
Other and further objects, advantages and features of the present invention will become apparent to one skilled in the art upon consideration of this entire disclosure. The form of the invention, which will now be described in detail, illustrates the general principals of the invention, but it is to be understood that this detailed description is not to be taken as limiting the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings, which drawings form a part of this specification.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
In the drawings:
FIG. 1 is a fragmentary sectional view of a valve having retained therein a high temperature packing assembly constructed in accordance with the present invention.
FIG. 2 is a fragmentary sectional view of the structure of FIG. 1 illustrating the high temperature packing assembly in greater detail.
FIG. 2a is a sectional view of a graphite seal ring prior to installation thereof within the valve of FIG. 1.
FIG. 3 is a sectional view of a high temperature valve packing assembly representing a modified embodiment of the present invention.
FIG. 4 is a fragmentary sectional view of a valve mechanism illustrating a high temperature valve stem packing assembly representing a further modified embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings and first to FIG. 1, a valve mechanism illustrated generally at 10 is illustrated in fragmentary section showing a valve body structure 12 having a valve stem passage 14 extending therethrough. Within the valve stem passage 14 is positioned a valve stem bushing 16, such as may be composed of brass or other suitable bearing material, that functions as a guide element for a valve stem member 18. The valve stem 18 defines a cylindrical outer surface 20 which is typically of rather fine surface finish and which may also be capable of passing through a packing assembly if the valve stem has linear movement during valve actuation. The valve stem, for purposes of this invention, may be capable of moving linearly, as in the case of gate valves, rotatably, as in the case of plug valves, or both linearly and rotatably as in the case of lift turn plug valves.
The valve stem passage 14 above the bushing 16 is enlarged so as to define an annular packing chamber or stuffing box 22 about the valve stem 18. Within the packing chamber 22 is located a packing assembly shown generally at 24 which is retained within the packing chamber by means of a packing retainer element 26. The packing retainer is secured in assembly with the valve body structure 12 by means of bolts 28 or by any other suitable form of retention.
Referring now to FIG. 2, the packing retainer 26 is formed to define internal and external seal grooves 30 and 32 respectively within which are received annular sealing elements 34 and 36 which may conveniently take the form of elastomeric O-rings or any other suitable form of sealing element. Sealing element 34 is adapted to maintain a fluid tight seal between the packing retainer 26 and the cylindrical surface 20 of the valve stem 18. The sealing element 36 maintains a positive seal between the packing retainer element 26 and the valve body 12 at the enlarged upper portion of the valve stem passage surface 14.
The packing retainer 26 defines an annular, generally cylindrical retainer rim portion 38 within which the seal groove 32 is formed. The free extremity of the packing retainer rim 38 defines a generally circular surface 40 of planer configuration. It should be borne in mind that the particular configuration of the planer surface 40 is not critical to the present invention. The surface 40 may be of any other suitable configuration mating with the configuration of the packing adapter ring in engagement therewith.
The packing assembly 24 is a high temperature packing assembly that is capable of maintaining a sealed relationship between the valve body structure and the valve stem even under circumstances where the valve is subjected to extremely high temperatures such as in the event of a fire. The packing assembly incorporates a plurality of graphite seal rings, three of which are shown at 42, 44 and 46. Each of the seal rings 42-46 are formed of graphite tape material which is helically wound to form a seal ring of the configuration illustrated in FIG. 2a. Graphite tape material such as that manufactured by the Union Carbide Corporation, New York, N.Y. and sold under the registered trademark "GRAFOIL" is utilized in the formation of the seal rings. As shown in FIG. 2a, the annular sealing element is in the form of a circular sealing ring composed of a number of graphite tape laminations that are formed such as by winding the tape about a mandrel that is of substantially the same outer diameter as the outer diameter of the valve stem 18. When originally wound, the graphite tape seal ring will have a generally rectangular cross-sectional configuration as shown in FIG. 2a. The laminations of the seal ring will be substantially parallel with an axis or center line extending through the center of the central opening 44 defined thereby. This axis or center line will be coincident with the center line of the valve stem 18 when the packing ring is installed within the packing chamber of stuffing box of the valve. Upon assembly of the seal ring within the stuffing box the laminations will be caused to slip, thus changing the seal ring from the rectangular cross-sectional configuration of FIG. 2a to the configuration of FIG. 2.
It should be borne in mind that although three graphite seal rings 42-46 are illustrated in FIG. 2, it is not intended thereby to limit the present invention to utilization of any particular number of graphite seal rings. For example, the packing assembly 24 may incorporate one or more such graphite seal rings within the spirit and scope of this invention.
Interposed between adjacent graphite seal rings are metal packing adapter rings, two of which are shown at 48 and 50. The packing adapter rings 48 and 50 are of substantially identical configuration defining generally planar circular surfaces 52 that are directed upstream in respect to pressure. Each of the packing adapter rings also define a circular surface of convex configuration as shown at 54 which is directed downstream in respect to pressure. The planar surfaces 52 of each of the packing adapter rings engage respective end surfaces 56 and 58 of the graphite seal rings 44 and 46 respectively. Since the surfaces 52 of the packing adapter rings are of planar configuration, they will mate with the planar end surfaces 56 and 58 of the graphite seal rings 44 and 46. The convex surfaces of the packing adapter rings 48 and 50 function to deform respective end surfaces of the graphite seal rings 42 and 44 to thus form corresponding concave circular end surfaces as shown at 60 and 62. The concave surfaces 60 and 62 are oriented facing upstream in respect to the pressure controlled by the valve. By forming the graphite seal rings in this manner, the inner and outer peripheral surfaces are forced to fit closely with respect to the metal surfaces of the valve body stem passage and the valve stem.
The outer portion of the packing assembly is defined by an outer adapter ring 64 which is also formed of metal and which defines a circular concave surface 66 having mating engagement with a convex surface 68 defined by the outer end surface of the graphite seal ring 42. Thus, both the inner and outer end surfaces of the graphite seal ring 42 are of curved cross-sectional configuration, the inner surface 60 being of concave configuration while the outer surface 68 thereof is of convex configuration. The outer end surface 70 of the packing adapter ring 64 is of planar configuration, thus mating with the planer configuration 40 defined by the inner end portion of the packing retainer rim 38.
The inner end portion the the packing assembly 24 is defined by an inner packing adapter ring 72 defining a convex outer surface 74 having mating engagement with a concave inner end surface 76 defined by the inner end portion of the graphite seal ring 46. Thus, each of the seal rings 42, 44 and 46 define concave circular end surfaces that face in the direction of pressure, providing each of the seal rings with the capability of expansion to urge the inner and outer peripheral surfaces thereof into optimum sealing engagement with the metal surfaces defining the packing chamber. The inner end surface 78 of the packing adapter 72 is of planar configuration and is adapted to be seated against an annular shoulder surface 80 defining the inner extremity of the packing chamber. The inner packing ring 72 is shown to be of substantially identical configuration as compared to the packing adapter rings 48 and 50. If desired, however, the inner extremity of the packing adapter ring 72 may take any other suitable configuration without departing from the spirit and scope of this invention. It is only necessary that the outer end surface 74 thereof be of convex configuration thus forming the inner end surface 76 of the seal ring 46 to a corresponding concave configuration.
It may be desirable to provide a high temperature packing assembly of the general nature as shown in FIG. 2, but to additionally provide the packing assembly with a spring-like characteristic. This feature is accomplished in the manner set forth in FIG. 3 which illustrates a packing assembly generally at 82 which is retained within a packing chamber by means of a packing retainer 84. The packing retainer is of substantially identical configuration with the packing retainer 26 of FIG. 2 and incorporates sealing members 86 and 88 to seal the packing retainer with respect to the valve stem 18 and the valve body structure 12. The packing assembly 82 incorporates a plurality of graphite seal rings 90, 92 and 94 which are of similar configuration as compared to the seal rings 42, 44 and 46 of FIG. 2. The inner and outer packing adapter rings 96 and 98 may be substantially identical with the respective packing adapter rings of FIG. 2. The intermediate packing adapter rings are each formed by packing ring assemblies including inner rings 100 and 102 of substantially flat configuration defining circular shoulders 104 and 106 at the respective inner peripheries thereof. A pair of spring ring elements 108 and 110 are placed in assembly with the flat rings 100 and 102 with the inner peripheries of the respective spring rings being in abutment with the circular shoulders 104 and 106. Each of the spring rings 108 and 110 is formed of sheet metal having spring characteristics, which sheet metal is in arcuate cross-sectional form defining convex outer surfaces 112 and 114 respectively. These convex outer surfaces are positioned in engagement with corresponding concave inner surfaces of the graphite seal rings 90 and 92 respectively. Since the outer surface 116 of the inner packing adapter ring 96 is of convex configuration, it should be observed that the inner end surfaces of each of the seal rings 90, 92 and 94 is of corresponding concave cross-sectional configuration.
As mechanical pressure is applied to the packing assembly, either by mechanical means forcing the packing adapter 84 in the direction of the packing assembly or fluid pressure acting against the inner end portion of the packing assembly, the packing assembly can yield in columnar manner. The spring-like intermediate packing adapter ring assemblies will yield by virtue of the spring nature of the curved spring elements 108 and 110. This feature provides the packing assemblies with the ability to compensate for mechanical tolerances and to yield in response to pressure increase. The packing adapter rings, including the intermediate ring assemblies, cooperate to maintain the inner extremities of the graphite seal rings in the proper arcuate concave configuration for optimum sealing capability. As packing wear occurs, the arcuate upper surfaces of each of the adapter rings causes the seal rings to deform in radial manner, thereby insuring optimum sealing relationship thereof with the respective metal surfaces of the valve body and valve stem.
A spring-like graphite packing assembly may also conveniently take the form shown in FIG. 4. A packing retainer element 118, having sealing members 120 and 122 located in annular grooves formed therein, functions to retain a packing assembly within a packing chamber defined by the cooperative relationship of the valve stem 18 with the valve body structure 12. The packing assembly which is illustrated generally at 124 includes graphite seal rings 126, 128 and 130 which are of the same structure and configuration as compared with the seal rings 90, 92 and 94 of FIG. 3. Packing adapter assemblies are positioned between adjacent seal rings such as shown at 132 and 134. Each of the packing adapter assemblies includes an inner ring element such as shown at 136 of generally flat configuration and an outer ring 138 of arcuate configuration, defining a convex outer surface 140 that engages the inner extremity of the adjacent graphite seal ring 126 or 128. An outer packing adapter ring 142 is generally identical with the outer packing adapter ring 98 of FIG. 3 and defines a circular surface 144 of concave configuration which engages the outer end surface of the outer seal ring 126 and thus maintains each extremity of the seal ring 126 in arcuate configuration, the inner end surface being of concave configuration while the outer end surface is of convex configuration.
At the inner end portion of the packing assembly 124 is provided an inner packing adapter ring 146 which is of arcuate configuration, defining a convex outer surface 148 which is in engagement with the inner end surface of the graphite seal ring 130. In each case, the arcuate packing adapter rings of the adapter ring assemblies or of the inner adapter ring are formed of metal having spring-like characteristics. This feature allows the packing assembly to be compressed somewhat by the packing retainer element 118. As wear occurs in the packing assembly, the spring-like members will maintain a spring force on the respective graphite seal rings, thus maintaining the degree of seal ring compression that is desirable for maintaining optimum sealing capability.
Regardless of the embodiment involved, application of extreme heat to the packing assemblies will not cause leakage to occur. Even though the O-ring type sealing elements of the packing retaining element will fail quite readily under intense heat, nevertheless, the graphite material of the graphite seal rings will efficiently maintain the respective sealing capability thereof. Any leakage that might occur will be insufficient to feed a fire and, therefore, fire fighting personnel will be enable to effectively control the fire. The high temperature packing assembly of this invention is, therefore, well adapted to attain all of the objects and features herein above set forth, together with other features which are inherent in the packing assembly itself. It will be understood that certain combinations and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is with the scope of the present invention.
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A high temperature valve stem packing incorporates a plurality of graphite seal rings composed of spirally coiled graphite tape and metal packing adapter rings being interposed between respective ones of the graphite seal rings. The metal packing adapter rings are of such configuration as to cause structural deformation of the end surface portions of the graphite rings to thereby induce the graphite seal rings to maintain the sealing capability thereof in response to wear during use and in response to fluid pressure applied thereto. In one form of the invention, the packing adapter rings are of solid construction and in another embodiment, the adapter rings are composed of pairs of interfitting rings which cooperate to define packing rings that are capable of yielding in spring-like manner as mechanical force or pressure induced force is transmitted to the packing assembly.
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FIELD OF THE INVENTION
[0001] This present invention generally relates to an automatic control system for a ripper used on construction equipment, and more specifically to automatically controlling ripper depth.
BACKGROUND OF THE INVENTION
[0002] Typically a ripper mounted on construction equipment such as a tractor is manually controlled by the operator who raises or lowers the ripper shank or varies the ripper pitch based upon experience, ground conditions, vehicle speed and other working conditions. Ripper depth is typically adjusted by removing a pin from the ripper shank and repositioning the shank relative to the ripper carrier and reinserting the pin. This effectively changes the length and potential depth of the ripper. This naturally requires operator time to reposition the ripper using the pin, and requires considerable skill and experience on the part of the operator to determine the desired depth to minimize the changes that need to be made to ripper length.
SUMMARY
[0003] A system is disclosed that limits the depth of a ripper mounted to a tractor by electronically sensing the lift cylinder length and limiting that length in order to limit the depth of ripper engagement with the ground.
[0004] A ripper depth limit system is disclosed for a ripper that includes a ripper lift cylinder. The ripper depth limit system includes an operator lift input, an operator ripper depth limit input, a lift cylinder sensor coupled to the ripper lift cylinder and a ripper electro-hydraulic controller. The operator lift input generates an operator lift signal that controls the raising and lowering of the ripper. The operator ripper depth limit input sets a ripper depth limit. The lift cylinder sensor senses the position of the ripper lift cylinder and generates a lift cylinder position signal. The ripper electro-hydraulic controller processes the operator lift signal, the lift cylinder position signal and the ripper depth limit; and generates and outputs ripper lift cylinder commands that do not allow the ripper depth to exceed the ripper depth limit. The ripper electro-hydraulic controller can include a position processor for determining a ripper position based on the lift cylinder position signal, where the position processor provides the ripper position for further processing by the ripper electro-hydraulic controller.
[0005] The operator ripper depth limit input can include an activation control for activating the ripper depth limit function, and a depth setting for setting the ripper depth limit. The operator ripper depth limit input can include a selector for selecting the ripper depth limit from a plurality of predefined depth limits. Alternatively, the operator ripper depth limit input can include a selector for selecting the ripper depth limit between a minimum ripper depth and a maximum ripper depth.
[0006] The ripper lift cylinder commands can be output to a ripper lift spool valve controlling the raising and lowering of the ripper. The ripper lift cylinder commands can be output to an output conditioning processor, and the output conditioning processor can output the conditioned ripper lift cylinder commands to a ripper lift spool valve controlling the raising and lowering of the ripper.
[0007] The ripper depth limit system can also include an operator pitch input, and a pitch cylinder sensor coupled to a ripper pitch cylinder, where he operator pitch input generates an operator pitch signal for controlling the pitch of the ripper; and the pitch cylinder sensor senses the position of the ripper pitch cylinder and generates a pitch cylinder position signal. The ripper electro-hydraulic controller can also process the operator pitch signal and the pitch cylinder position signal to generate and output ripper pitch cylinder commands that do not allow the ripper depth to exceed the ripper depth limit. The ripper pitch cylinder commands can be output to a ripper pitch spool valve controlling the pitch of the ripper. The ripper pitch cylinder commands can be output to an output conditioning processor that outputs conditioned ripper pitch cylinder commands to a ripper pitch spool valve controlling the pitch of the ripper. The ripper electro-hydraulic controller can include a position processor for determining a ripper position based on the lift and pitch cylinder position signals.
[0008] A ripper depth limit method is disclosed for controlling a ripper coupled to a lift cylinder that raises and lowers the ripper. The ripper depth limit method includes setting a ripper depth limit, reading a lift cylinder position from a sensor coupled to the lift cylinder, determining a ripper position using the lift cylinder position reading, receiving a ripper lift cylinder command from an operator control device, and determining whether executing the ripper lift cylinder command will cause the ripper to exceed the ripper depth limit. When the ripper lift cylinder command will not cause the ripper to exceed the ripper depth limit, the method includes executing the ripper lift cylinder command. When the ripper lift cylinder command will cause the ripper to exceed the ripper depth limit, the method includes revising the ripper lift cylinder command to not cause the ripper to exceed the ripper depth limit and executing the revised ripper lift cylinder command. The method then includes returning to receive another ripper lift cylinder command.
[0009] After the determining a ripper position step and before the receiving a ripper lift command step, the ripper depth limit method can include determining whether the ripper position exceeds the ripper depth limit; and when it exceeds the ripper depth limit, generating a ripper lift command to raise the ripper to the ripper depth limit. After the receiving a ripper lift cylinder command step, the ripper depth limit method can include determining whether the ripper depth limit functionality is still activated; and when it is not still activated, executing the ripper lift cylinder command and exiting the ripper depth limit method.
[0010] Setting a ripper depth limit can include reading one of a plurality of predefined depth limit values from a depth limit selector. Alternatively, setting a ripper depth limit can include determining a position of a selector between a minimum and maximum value, and determining the ripper depth limit based on the position of the selector.
[0011] A ripper depth limit method is disclosed for controlling a ripper coupled to a lift cylinder that raises and lowers the ripper and a pitch cylinder the controls the pitch of the ripper. The ripper depth limit method includes setting a ripper depth limit, reading a lift cylinder position from a lift sensor coupled to the lift cylinder, reading a pitch cylinder position from a pitch sensor coupled to the pitch cylinder, determining a ripper position using the lift and pitch cylinder position readings, receiving a ripper lift or pitch cylinder command from an operator control device, and determining whether executing the ripper lift or pitch cylinder command will cause the ripper to exceed the ripper depth limit. When the ripper lift or pitch cylinder command will not cause the ripper to exceed the ripper depth limit, the method includes executing the ripper lift or pitch cylinder command. When the ripper lift or pitch cylinder command will cause the ripper to exceed the ripper depth limit, the method includes revising the ripper lift or pitch cylinder command to not cause the ripper to exceed the ripper depth limit and executing the revised ripper lift or pitch cylinder command. The method then includes returning to receive another ripper lift or pitch cylinder command.
[0012] After the determining a ripper position step and before the receiving a ripper lift or pitch cylinder command step, the ripper depth limit method can include determining whether the ripper position exceeds the ripper depth limit, and when it exceeds the ripper depth limit, generating a ripper lift command to raise the ripper to the ripper depth limit. After the receiving a ripper lift or pitch cylinder command step, the ripper depth limit method can include determining whether the ripper depth limit functionality is still activated, and when it is not still activated, executing the ripper lift or pitch cylinder command and exiting the ripper depth limit method.
[0013] The step of revising the ripper lift or pitch cylinder command to not cause the ripper to exceed the ripper depth limit can include: for a ripper lift cylinder command, revising the ripper lift cylinder command to lower the ripper to the ripper depth limit only; and for a ripper pitch cylinder command, generating and executing a ripper lift cylinder command to raise the ripper and executing the ripper pitch cylinder command so the ripper does not exceed the ripper depth limit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates an exemplary embodiment of a ripper coupled to a crawler;
[0015] FIG. 2 illustrates an exemplary electro-hydraulic (EH) system for controlling a ripper;
[0016] FIG. 3 illustrates a more detailed view of an exemplary embodiment of the EH controller that can be used in the EH system of FIG. 2 ;
[0017] FIG. 4 is a flow diagram of an exemplary control process for a ripper depth limit system that uses sensor readings from the ripper lift cylinder(s); and
[0018] FIG. 5 is a flow diagram of an exemplary control process for a ripper depth limit system that uses sensor readings from the ripper lift and pitch cylinders.
DETAILED DESCRIPTION
[0019] For the purposes of promoting an understanding of the principles of the novel invention, reference will now be made to the embodiments described herein and illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the novel invention is thereby intended, such alterations and further modifications in the illustrated devices and methods, and such further applications of the principles of the novel invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the novel invention relates.
[0020] A system is disclosed that limits the depth of a ripper attached to a crawler by electronically sensing the lift cylinder length and limiting that length in order to limit the depth of ripper engagement with the ground. The system can include electro-hydraulic (EH) valves, a microprocessor, an operator input device, and a sensor for sensing the length of at least one of the ripper carrier lift cylinders. When the operator commands a ripper lower function, a limiting function can be used to limit the minimum length of the ripper cylinder to either a predefined or custom defined length which effectively limits the ripper engagement depth.
[0021] FIG. 1 illustrates an exemplary embodiment of a ripper 110 coupled to a crawler 100 . The ripper 110 includes a shank holder 112 , a ripper shank 114 with a tip 116 , a pair of ripper pitch cylinders 120 , a pair of ripper lift cylinders 130 and a pair of links 140 . The proximal ends of the ripper pitch cylinders 120 , the ripper lift cylinders 130 and the links 140 are coupled to the crawler 100 and the distal ends of the ripper pitch cylinders 120 , the ripper lift cylinders 130 and the links 140 are coupled to the shank holder 112 . The ripper lift cylinders 130 can be extended and retracted to raise and lower the ripper 114 . The pair of ripper pitch cylinders 120 can be extended and retracted to change the pitch of the ripper 114 . The ripper shank 114 can be manually raised or lowered in the shank holder 112 .
[0022] FIG. 2 illustrates an exemplary electro-hydraulic (EH) system 200 for controlling a ripper. The EH system 200 includes a ripper EH controller 202 , a lift spool valve 250 , a pitch spool valve 260 , a pair of lift cylinders 210 , 220 , a pair of pitch cylinders 230 , 240 , a flow source P and a sink. The ripper EH controller 202 receives operator and system inputs and generates output signals to control the spool valves and cylinders.
[0023] The ripper EH controller 202 receives operator inputs from a ripper lift controller 204 , a ripper pitch controller 206 and a ripper depth limit controller 208 . The ripper lift and pitch controllers 204 , 206 can be any of various types of controllers known in the art, for example a single joystick for both lift and pitch control, or separate joysticks for each of lift and pitch control. The ripper depth limit controller 208 can also be of various types of controllers, for example a switch, knob, button, menu, etc. The ripper EH controller 202 processes the operator inputs to control the ripper.
[0024] At least one of the ripper lift cylinders 210 , 220 has a lift cylinder position sensor 214 . The lift cylinder position sensor 214 senses the position of the piston 212 in the lift cylinder 210 and sends a sensor output to the ripper EH controller 202 . The ripper EH controller 202 can use the output of the lift cylinder position sensor 214 to determine the position of the ripper relative to the main geometry of the tractor.
[0025] One of the ripper pitch cylinders 230 , 240 can have a pitch cylinder position sensor 234 . The pitch cylinder position sensor 234 senses the position of the piston 232 in the pitch cylinder 230 and sends a sensor output to the ripper EH controller 202 . The ripper EH controller 202 can use the output of the pitch cylinder position sensor 234 to more accurately determine the position of the ripper relative to the main geometry of the tractor. As shown below, it is optional to include position sensors on the pitch cylinders for the ripper depth limiting system.
[0026] The ripper EH controller 202 processes the operator and sensor inputs and sends control signals to the lift spool valve 250 and the pitch spool valve 260 . The lift spool valve 250 includes a first movement actuator 252 and a second movement actuator 254 to move the lift spool valve 250 to a desired position. The lift spool valve 250 also includes an input side (bottom) coupled to a flow source P, for example a pump, and an output side (top) coupled to the lift cylinders 210 , 220 . The first movement actuator 252 can be used to move the lift spool valve 250 to retract the lift cylinders 210 , 220 . The second movement actuator 254 can be used to move the lift spool valve 250 to extend the lift cylinders 210 , 220 .
[0027] The pitch spool valve 260 includes a first movement actuator 262 and a second movement actuator 264 to move the pitch spool valve 260 to a desired position. The pitch spool valve 260 also includes an input side (top) coupled to a flow source P, for example a pump, and an output side (bottom) coupled to the pitch cylinders 230 , 240 . The first movement actuator 262 can be used to move the pitch spool valve 260 to retract the pitch cylinders 230 , 240 . The second movement actuator 264 can be used to move the pitch spool valve 260 to extend the pitch cylinders 230 , 240 .
[0028] FIG. 3 illustrates a more detailed view of an exemplary embodiment of the ripper EH controller 202 . The ripper EH controller 202 includes a table of geometric relationships 306 which can be used to determine ripper position relative to the tractor based on system parameters including ripper lift and pitch cylinder positions. The inputs from the lift cylinder position sensor 214 and the pitch cylinder position sensor 234 are processed by a cylinder position processor 304 which also uses the table of geometric relationships 306 to determine ripper position data. The ripper position data computed by the position processor 304 is sent to an operator command processor 302 and to a position limiting processor 310 .
[0029] The operator command processor 302 processes the ripper position data generated by the position processor 304 , along with the inputs from the operator lift and pitch controllers 204 , 206 , and the table of geometric relationships 306 to generates lift cylinder commands and pitch cylinder commands. The lift and pitch cylinder commands are both sent to the position limiting processor 310 .
[0030] The input from the ripper depth limit selector 208 is processed by a ripper depth limit processor 308 to generate a ripper depth limit command. The ripper depth limit command generated by the ripper depth limit processor 308 is sent to the position limiting processor 310 .
[0031] The position limiting processor 310 processes the inputs from the operator command processor 302 and the ripper depth limit processor 308 , and uses the table of geometric relationships 306 to determine lift and pitch cylinder commands to send to an output conditioning processor 312 . If the ripper depth limit option is active, and the operator commands would cause the ripper to exceed the depth limit, then the position limiting processor 310 would modify the ripper lift and pitch commands to execute the operator commands without exceeding the depth limit.
[0032] The output conditioning processor 312 sends commands from the ripper EH controller 202 to the lift spool valve 250 and the pitch spool valve 260 . The output conditioning processor 312 sends lift commands to the movement actuators 252 , 254 to position the lift spool valve 250 and control the lift cylinders 210 , 220 . The output conditioning processor 312 sends pitch commands to the movement actuators 262 , 264 to position the pitch spool valve 260 and control the pitch cylinders 230 , 240 .
[0033] FIG. 4 is a flow diagram of an exemplary implementation of a control process for the ripper depth limit that uses sensor readings from the lift cylinder(s) and not the pitch cylinder(s). When a command is processed, at block 402 the system checks if the ripper depth limit is activated. If the ripper depth limit is activated then control is passed to block 408 , otherwise control is passed to block 404 . At block 404 , the system checks if the command is a lift cylinder command. If the command is a lift cylinder command then control is passed to block 406 , otherwise the system returns to process the next command. At block 406 , the system executes the lift cylinder command and then returns to process the next command.
[0034] If the ripper depth limit option is activated, then at block 408 the system retrieves and sets the ripper depth limit and then at block 410 the system checks the length of the ripper lift cylinder(s). Then at block 412 , the system checks if the ripper depth limit is exceeded. If the ripper depth limit is exceeded then control is passed to block 414 , otherwise control is passed to block 416 . At block 414 , the system retracts the ripper lift cylinders to raise the ripper to the ripper depth limit, and then passes control to block 416 .
[0035] At block 416 the system waits for a lift cylinder command. When a lift cylinder command is received, control passes to block 418 where the system checks if the ripper depth limit option is still activated. If the ripper depth limit option is not still activated then at step 406 the lift cylinder command is executed and control is passed back to block 402 to wait for the depth limit option to be activated again. If the ripper depth limit option is still activated then control is passed to block 420 .
[0036] At block 420 the system determines whether the lift command will lower the ripper beyond the depth limit. If the lift command will not lower the ripper beyond the depth limit then the lift cylinder command is executed at block 422 , and control is passed back to block 416 to wait for the next lift cylinder command. If the lift command would lower the ripper beyond the depth limit then the lift cylinder command is revised at block 424 to only lower the ripper to the depth limit, the revised lift cylinder command is executed at block 422 , and control is passed back to block 416 to wait for the next lift cylinder command.
[0037] FIG. 5 is a flow diagram of an exemplary implementation of a control process for the ripper depth limit that uses sensor readings from both the lift and pitch cylinders. When a command is processed, at block 502 the system checks if the ripper depth limit is activated. If the ripper depth limit is activated then control is passed to block 508 , otherwise control is passed to block 504 . At block 504 , the system checks if the command is a ripper lift or pitch cylinder command. If the command is a ripper lift or pitch cylinder command then control is passed to block 506 , otherwise the system returns to process the next command. At block 506 , the system executes the ripper lift or pitch cylinder command, and then returns to process the next command.
[0038] If the ripper depth limit option is activated, then at block 508 the system retrieves and sets the ripper depth limit, then at block 410 the system checks the length of the ripper lift and pitch cylinders, and at block 512 the system determines the ripper depth. Then at block 514 , the system checks if the ripper depth exceeds the ripper depth limit. If the ripper depth limit is exceeded then control is passed to block 516 , otherwise control is passed to block 518 . At block 516 , the system retracts the ripper lift cylinders to raise the ripper to the ripper depth limit, and then passes control to block 518 .
[0039] At block 518 the system waits for a ripper lift or pitch cylinder command. When a ripper lift or pitch cylinder command is received, control passes to block 520 where the system checks if the ripper depth limit option is still activated. If the ripper depth limit option is not still activated then at step 506 the ripper lift or pitch cylinder command is executed and control is passed back to block 502 to wait for the depth limit option to be activated again. If the ripper depth limit option is still activated then control is passed to block 522 .
[0040] At block 522 the system determines whether the ripper lift or pitch command will lower the ripper beyond the depth limit. If the ripper lift or pitch command will not lower the ripper beyond the depth limit then the command is executed at block 524 , and control is passed back to block 518 to wait for the next ripper lift or pitch cylinder command. If the ripper lift or pitch command would lower the ripper beyond the depth limit then the command is revised at block 526 to only lower the ripper to the depth limit or raise the ripper to the depth limit if the pitch command would lower the ripper beyond the depth limit. From block 526 control is passed to block 524 where the revised lift or pitch cylinder command is executed, and then control is passed back to block 518 to wait for the next ripper lift or pitch cylinder command.
[0041] While exemplary embodiments incorporating the principles of the present invention have been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
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A ripper depth limit system and method is disclosed. The ripper depth limit system includes a lift input for operator controls to raise and lower the ripper, a depth limit input, a lift sensor input that senses the ripper lift cylinder position, and a controller that processes the inputs to generate, execute and revise ripper lift cylinder commands that keep the ripper above the ripper depth limit. The depth limit input can select the ripper depth limit from a plurality of predefined depth limits, or between minimum and maximum ripper depths, or by other means. The ripper depth limit system can also include a pitch input for operator controls of ripper pitch, and a pitch sensor that senses ripper pitch cylinder position, and the controller can process the pitch inputs to generate, execute and revise ripper pitch and lift cylinder commands that keep the ripper above the ripper depth limit.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a connecting method for wax patterns of a golf club head. More particularly, the present invention relates to the connecting method of employing volume's shrinkage of wax patterns for combining with each other that may simplify an assembling process for the wax patterns of the golf club head.
[0003] 2. Description of the Related Art
[0004] Referring initially to FIGS. 1 through 3 , Taiwanese Pat. Publication No. 514574 discloses a manufacturing method for a golf club head. The manufacturing method includes the steps of:
[0005] 1. Separately prefabricating two wax patterns 10 , 20 , as shown in FIG. 1 . Wax liquid is injected into a first mold assembly and a second mold assembly (not shown) to form two wax patterns 10 , 20 , such as a main-body wax pattern 10 and a striking-plate wax pattern 20 .
[0006] 2. Adhering the two wax patterns, as shown in FIG. 1 . The two wax patterns 10 , 20 are adhered to constitute a combination member.
[0007] 3. Forming a ceramic shell 30 in slurry, as shown in FIG. 2 . The combination pattern of the two wax patterns 10 , 20 is immersed in slurry that forms a ceramic shell 30 . After heating, the two wax patterns encompassed in the ceramic shell 30 are changed to the melting wax liquid for discharging it from the ceramic shell 30 . The ceramic shell 30 forms an inward protrusion for correspondingly casting a rear recession of a golf club head, and a pouring gate at its side portion.
[0008] 4. Investment casting an iron club head within the ceramic shell 30 , as shown in FIG. 3 . A melting alloy is poured into the ceramic shell 30 to fabricate the iron club head. After cooling, the iron club head casting 40 is formed within the ceramic shell 30 which can be broken to take out an integrated member of the iron club head casting 40 .
[0009] According to the above-mentioned manufacturing method, the club head casting 40 forms a rear recession 41 at its rear side to constitute an undercut configuration that may enhance striking performance and satisfy the need of product quality. However, there are several drawbacks in manufacturing. For example, in adhering process the wax liquid is generally filled within a groove extending between the main-body wax pattern 10 and the striking-plate wax pattern 20 . As best shown in FIGS. 1 a , 2 a and 3 a , when the filling process is incomplete, there exists a gap (a) remained between the main-body wax pattern 10 and the striking-plate wax pattern 20 . Thus, the slurry may invade into the gap (a) in the immersing process for forming the ceramic shell. Consequently, the interior of the ceramic shell 30 may consists of burrs (b) after lost-wax processing. In investment casting process, the club head casting 40 may form many cracks (c) between a main-body wax portion and a striking-plate wax portion due to the burrs (b). Furthermore, an excess of the wax liquid cause an overflow from the groove between the main-body wax pattern 10 and the striking-plate wax pattern 20 . After hardening, although the harden wax may fill the groove formed between the main-body wax pattern 10 and the striking-plate wax pattern 20 , an irregular surface (not shown) may remain on the groove of the combination member. Hence, there is a need for eliminating the irregular surface of the club head casting 40 by precision machining or polishing. This results in an additional process in manufacturing the golf club head. Especially, if the irregular surface is remained in the rear recession 41 of the club head casting 40 , a machining tool is hard or inconvenient for inserting into the rear recession 41 of the club head casting 40 for processing. Certainly, it may result in difficulty of machining, and an increase of manufacturing cost and time.
[0010] The present invention intends to provide a connecting method for wax patterns a golf club head which delays cooling a first wax pattern in proper and cools a second wax pattern. A manufacturing volume tolerance is enlarged between the first and second wax patterns for conveniently combining each other in such a way to mitigate and overcome the above problem.
SUMMARY OF THE INVENTION
[0011] The primary objective of this invention is to provide a connecting method for wax patterns a golf club head which employs a temperature difference of the wax patterns to generate a manufacturing volume tolerance between the wax patterns. Thereby the wax patterns are able to fittingly combine each other that may increase the overall quality of the golf club head.
[0012] The connecting method for the wax patterns of the golf club head in accordance with the present invention includes the steps of: prefabricating a first wax pattern and a second wax pattern, the first wax pattern providing with an engaging portion for engaging with the second wax pattern; employing a temperature difference to generate a manufacturing volume tolerance between the first wax pattern and the second wax pattern; combining the engaging portion of the first wax pattern with the second wax pattern; and cooling the first wax pattern to shrink the engaging portion so as to fittingly combine the first wax pattern with the second wax pattern.
[0013] Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will now be described in detail with reference to the accompanying drawings wherein:
[0015] FIG. 1 is a cross-sectional view of wax patterns of a conventional golf club head in accordance with the prior art;
[0016] FIG. 1 a is an enlarged view, in FIG. 1 , of the wax patterns of the golf club head in accordance with the prior art;
[0017] FIG. 1 b is another enlarged view, similar to FIG. 1 a , of the wax patterns of the golf club head in accordance with the prior art;
[0018] FIG. 2 is a cross-sectional view of a ceramic shell of the golf club head in accordance with the prior art;
[0019] FIG. 2 a is an enlarged view, in FIG. 2 , of the ceramic shell of the golf club head in accordance with the prior art;
[0020] FIG. 3 is a cross-sectional view of a club head casting in accordance with the prior art;
[0021] FIG. 3 a is an enlarged view, in FIG. 3 , of the club head casting in accordance with the prior art;
[0022] FIG. 4 is a block diagram of a connecting method for wax patterns a golf club head in accordance with the present invention;
[0023] FIG. 5 is an exploded perspective view of wax patterns of the golf club head in a first step of a connecting method in accordance with the first embodiment of the present invention;
[0024] FIG. 6 a is a cross-sectional view of the striking-plate wax pattern of the golf club head in a second step of the connecting method in accordance with the first embodiment of the present invention;
[0025] FIG. 6 b is a cross-sectional view, similar to FIG. 6 a , of the shrunk striking-plate wax pattern of the golf club head in a second step of the connecting method in accordance with the first embodiment of the present invention;
[0026] FIG. 7 a is a cross-sectional view of the combined wax patterns of the golf club head in a third step of the connecting method in accordance with the first embodiment of the present invention;
[0027] FIG. 7 b is a cross-sectional view of the combined wax patterns of the golf club head in a fourth step of the connecting method in accordance with the first embodiment of the present invention;
[0028] FIG. 8 is a cross-sectional view of a ceramic shell of the golf club head in accordance with the first embodiment of the present invention;
[0029] FIG. 9 is a cross-sectional view of a club head casting in accordance with the first embodiment of the present invention;
[0030] FIG. 10 is a cross-sectional view of a main-body wax pattern of the golf club head in a second step of the connecting method in accordance with a second embodiment of the present invention;
[0031] FIG. 11 a is a cross-sectional view of the combined wax patterns of the golf club head in a third step of the connecting method in accordance with the second embodiment of the present invention; and
[0032] FIG. 11 b is a cross-sectional view of the combined wax patterns of the golf club head in a fourth step of the connecting method in accordance with the second embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0033] The reference numerals of the first and second embodiments of the present invention have applied the identical numerals of the conventional golf club head members, as shown in FIGS. 1 through 3 . The construction of golf club head member members in accordance with embodiments of the present invention have similar configuration and same function as that of the conventional golf club head members and detailed descriptions may be omitted.
[0034] Referring to FIGS. 4 and 5 , a first step of the connecting method for the wax patterns in accordance with a first embodiment of the present invention separately prefabricates a first wax pattern 10 and a second wax pattern 20 . The construction of the first wax pattern 10 provides with a rear opening 11 and an engaging portion 12 connected thereto. First, wax liquid is injected into a mold assembly (not shown) for separately prefabricating the first wax pattern 10 and the second wax pattern 20 . Preferably, the first wax pattern 10 and the second wax pattern 20 are club component patterns selected from a group consisting of a main-body wax pattern and a striking-plate wax pattern for example. In the illustrated embodiment the opening 11 of the main-body wax pattern 10 connects the rear side to the front side. Furthermore, the rear opening 11 of the first wax pattern 10 connects to the engaging portion 12 proximate the front side for engaging with the second wax pattern 20 .
[0035] Turning now to FIGS. 4, 6 and 6 a , a second step of the connecting method for the wax patterns in accordance with the first embodiment the present invention employs a temperature difference to generate a manufacturing volume tolerance between the first wax pattern 10 and the second wax pattern 20 . The material of wax may expand when hot and shrink when cool, which has a shrinkage rate in length ranging between 8/1000- 17/1000. To accomplish such a manufacturing volume tolerance, the second wax pattern 20 is processed to cool in proper for shrinking volume thereof. After cooling down to a predetermined low temperature, a first outer diameter L 2 of the second wax pattern 20 is reduced to a second outer diameter L 2 ′. In order to maintain an inner diameter L 1 of the engaging portion 12 of the first wax pattern 10 in a greater length, the first wax pattern 10 is thermal-insulated at a predetermined high temperature that is relatively higher than that of the second wax pattern 20 . In the same temperature, the first outer diameter L 2 of the second wax pattern 20 may be slightly greater than the inner diameter L 1 of the engaging portion 12 of the first wax pattern 10 prior to cooling the second wax pattern 10 . In different temperature, the second outer diameter L 2 ′ of the second wax pattern 20 may be specifically smaller than the inner diameter L 1 of the engaging portion 12 of the first wax pattern 10 for loose-fitting. Because of this, the temperature difference permits a desired manufacturing volume tolerance between the first wax pattern 10 and the second wax pattern 20 .
[0036] Turning now to FIGS. 4 and 7 a , a third step of the connecting method for the wax patterns in accordance with the first embodiment of the present invention initially combines the engaging portion 12 of the first wax pattern 10 with the second wax pattern 20 . After cooling the second wax pattern 20 , the second outer diameter L 2 ′ is able to insert into the inner diameter L 1 of the engaging portion 12 in convenience by means of loose fitting. In assembling, the inner diameter L 1 of the engaging portion 12 of the first wax pattern 10 may not interfere with the second outer diameter L 2 ′ of the second wax pattern 20 such that a connection boundary between the first and the second wax patterns may not be destroyed. Consequently, it ensures the constructions of the first wax pattern 10 and the second wax pattern 20 in good condition.
[0037] Turning now to FIGS. 4 and 7 b , a fourth step of the connecting method for the wax patterns in accordance with the first embodiment of the present invention cools the first wax pattern 10 to shrink the engaging portion 12 . Thereby the engaging portion 12 fittingly combines the first wax pattern 10 with the second wax pattern 20 to form a wax club head 100 . To this end, the engaging portion 12 of the first wax pattern 10 may be gradually shrunk to engage with an outer circumference of the second wax pattern 20 when the temperature is successively decreased. Finally, since the second outer diameter L 2 ′ is substantially equal to or slightly greater than the reduced inner diameter of the engaging portion 12 , an inner circumference of the engaging portion 12 fittingly combines with the outer circumference of the second wax pattern 20 . Consequently, there is no gap remained between the inner circumference of the engaging portion 12 and the outer circumference of the second wax pattern 20 that may increase the overall quality of the golf club head.
[0038] Turning now to FIGS. 8 and 9 , subsequently, the wax club head 100 is immersed in slurry to form a ceramic shell 30 and heats the ceramic shell 30 for lost-wax processing. Next, a melting alloy is poured into the ceramic shell 30 to fabricate a club head casting 40 . Finally, the club head casting 40 can be taken out by breaking the ceramic shell 30 .
[0039] In the illustrated embodiment the wax club head 100 can omit a filling process of wax liquid that avoids an overflow due to an excess of the wax liquid or incomplete filling which causes an irregular surface. This results in the wax club head 100 forming a smooth surface instead of an irregular surface. Consequently, the club head casting 40 has a smooth surface that may increase the overall quality of the golf club head. Also, the smooth surface of the club head casting 40 results in a decrease in the need of precision machining that may simplify the machining process and reduce manufacturing cost.
[0040] Turning now to FIGS. 10, 11 a and 11 b , the connecting method for the wax patterns in accordance with a second embodiment of the present invention, in comparison with the first embodiment, employs a heater (not shown) heating the first wax pattern 10 to maintain it at a predetermined high temperature. Once the predetermined low temperature of the second wax pattern 20 is relatively lower than that of the first wax pattern 10 , a desired manufacturing volume tolerance between the first wax pattern 10 and the second wax pattern 20 is obtained. However, for strength and rigidity, the heating temperature of the first wax pattern 10 is considerably lower than a melting point so that the construction of the first wax pattern 10 is relatively rigid and strong to withstand normal usage in manufacture. In this circumstance, the inner diameter L 1 of the engaging portion 12 is remained in a greater length. As best shown in FIG. 1 a , after successively heating the first wax pattern 10 , the inner diameter L 1 of the engaging portion 12 of the first wax pattern 10 may be specifically greater than the outer diameter L 2 ′ of the second wax pattern 20 for loose-fitting. As best shown in FIG. 11 b , the inner diameter L 1 of the engaging portion 12 of the first wax pattern 10 may be gradually shrunk to engage with the outer circumference L 2 ′ of the second wax pattern 20 when the temperature is successively decreased. Finally, since the second outer diameter L 2 ′ is slightly greater than the reduced inner diameter of the engaging portion 12 , an inner circumference of the engaging portion 12 fittingly combines with the outer circumference of the second wax pattern 20 to form a wax club head 100 . Consequently, there is no gap remained between the inner circumference of the engaging portion 12 and the outer circumference of the second wax pattern 20 that may increase the overall quality of the golf club head. Referring back to FIGS. 8 and 9 , the wax club head 100 is used to fabricate the ceramic shell 30 and the club head casting 40 .
[0041] Referring back to FIGS. 3 and 3 a , the conventional club head casting 40 has many cracks (c) due to the gap (a) formed between the main-body wax pattern 10 and the striking-plate wax pattern 20 . Referring back to FIG. 4 , the first wax pattern 10 is thermal-insulated or heated at a predetermined high temperature to obtain a desired manufacturing volume tolerance between the first wax pattern 10 and the second wax pattern 20 . Consequently, it may increase the overall quality of the golf club head.
[0042] Although the invention has been described in detail with reference to its presently preferred embodiment, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims.
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A connecting method for the wax patterns of the golf club head includes the steps of: prefabricating a first wax pattern and a second wax pattern, the first wax pattern providing with an engaging portion for engaging with the second wax pattern; employing a temperature difference to generate a manufacturing volume tolerance between the first wax pattern and the second wax pattern; combining the engaging portion of the first wax pattern with the second wax pattern; and cooling the first wax pattern to shrink the engaging portion so as to fittingly combine the first wax pattern with the second wax pattern.
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RELATED APPLICATIONS
[0001] This application claims priority to provisional Application Serial No. 60/452,793 filed Mar. 7, 2003.
BRIEF DESCRIPTION OF THE INVENTION
[0002] This invention relates to apparatus and method for testing electronic systems, and more particularly to apparatus and method for functionally testing electronic systems at clock rates of 1 GHz and higher.
BACKGROUND OF THE INVENTION
[0003] Conventional test methods include a hierarchy of tests including wafer probe testing, packaged part testing, and system testing. In each of these, it is customary to use a test fixture between the device under test, DUT, and the tester. The test fixture normally includes a switch matrix for connecting tester pins to DUT pins, and a collection of driver and receiver circuits, switches and relays that are commonly referred to as the “pin electronics” of the tester.
[0004] In digital systems, clock rates have increased to 1 GHz and beyond. At high frequencies it becomes desirable to place components close together, and minimize trace lengths. To this end, systems have been produced that employ bare IC chips rather than packaged parts, with the IC chips attached to the system board using flip chip bonding methods, resulting in dense systems and short trace lengths. It is similarly desirable to minimize the electrical path lengths between a system under test, SUT, and the comparator circuits that are used to verify system behavior.
[0005] Conventional testing methods provide a hierarchy of inspections and tests for testing complex systems. Automatic optical inspection, AOI, employs cameras and lighting systems to examine board assemblies for correct component placement and orientation, acceptable traces and solder joints. Automated X-ray inspection, AXI, can check solder joints that are hidden from AOI equipment. In circuit test, ICT, is often employed to measure values of discrete components, and to find open and short circuits. The fixture for ICT is typically a grid of electronic probes (or “bed of nails”) that make contact with test points designed into the board assembly. The maximum number of nodes that can be tested using ICT is currently around 7,000. Complex system boards may have 10,000 nodes and upward. Boundary scan is a test method commonly used to check that all components are present and properly oriented. Boundary scan methods add logic and control signals to each component, internal blocks are chained together, and access to internal nodes is greatly improved. After all the passive elements of the system have been verified and boundary scan has been performed, a board functional test is typically required. Normally, a test fixture is used to connect system nodes to tester nodes. With the system under power, stimulus vectors are applied while system outputs are measured for the correct values. A lot of effort is required to determine the stimulus vectors and the correct system responses, and the effort increases as system complexity increases. For some complex systems this approach is abandoned because the time and effort are judged to be too great. In these cases, less rigorous testing may be accomplished using a “hot mockup” which is a version of the end-user system, or by using system equivalency tests. These methods are weak in terms of diagnosing problems, because only system level results are accessible.
[0006] Recent test fixtures have included expensive GaAs circuits for increased switching speed and electro-optical receivers for isolation between test circuits. Despite these efforts, some systems cannot be tested at full speed and others have to compromise on test coverage to keep the test time within reasonable bounds.
[0007] Recent advances in high-density interconnection (HDI), circuits, and in flip chip bonding techniques have made it possible to add additional IC chips to a system board at a low assembly cost. Also, advances in IC chip design and implementation make it possible to include most or all of the functions of a sophisticated tester on a single IC chip, especially if the pin electronics are simplified.
[0008] Built in self test (BIST) is a methodology that has been developed for testing individual components by providing test circuits within the component, rather than connecting them to an external tester. TOB is similar in concept, except that the test target is a system board rather than a component of that board.
SUMMARY OF THE INVENTION
[0009] The proposed test method, tester on board (TOB), performs the system functional test with most of the tester functionality implemented on an IC test chip that is placed on the system board. The test chip is connected to system nodes using the interconnection method of the system board; preferably the components are assembled as bare die using flip chip assembly methods. Since in circuit tests and boundary scans are typically low speed tests employing simple test hardware, they are preferably provided by a test support computer that includes such hardware, without involving the IC test chip.
[0010] In the preferred embodiment, a single test chip samples test signals of three different types: digital, analog, and radio frequency (RF). The digital signals are carried on digital bus lines, the analog signals are carried on analog bus lines, and the RF signals are sampled at antenna inputs. System behavior is evidenced by the various signals sampled and tested at the discrete instants in time represented by test cycles. The ultimate format for each item of captured behavior is preferably a test vector or digital word, although analog comparisons may be preferred for parametric tests such as a leakage current test. The main focus of this application applies to functional testing of digitized signals. However, reference sources including voltage and current sources, amplifiers and analog comparators may be included in the preferred test hardware for parametric testing. For digital signals the number of bits in the word corresponds to the number of digital bits sampled. Analog test signals are preferably converted from analog to digital format; the number of bits in each analog test vector is calculated as the number of analog signals sampled times the number of digitized bits per sample. RF test signals may be down-converted to a suitable intermediate frequency, then demodulated and digitized. The number of bits in each RF test vector is equal to the number of RF signals sampled times the number of digitized bits per sample.
[0011] The test system includes a learn mode and a test mode. The learn mode allows test vectors generated during selected cycles of system behavior to be automatically accumulated in memory. These vectors can be created by a reference system that is hopefully fully functional, or close to fully functional. The cycles selected are test cycles; they capture critical system behaviors or responses. Eliminating redundant or unnecessary test cycles has the benefit of reducing the required amount of memory on the test chip. The test program starts at time=0 with cycle count=0. The cycle count increments with each cycle of the timing reference or system clock. The temporal locations of selected cycles (cycle counts) are captured in a test mask which includes a memory bit for each test cycle performed. A “1” in the mask memory represents a selected cycle for which verification is required (a test cycle); a “0” represents an unselected cycle for which verification is not required. Typically, only a small percentage of total system cycles are required to be test cycles in order to reliably validate system behavior.
[0012] Successive approximations are employed to capture and refine the learned behavior of a properly functioning system. The goal is to automate the process where possible, avoid writing a detailed test program in a software language foreign to the system designers, and reduce the amount of labor required to optimize the selection of effective test vectors. After the learned behavior is refined and verified, the test vectors become proven test vectors; they can be loaded into reference memories for comparison with observed behavior of a system under test (SUT).
[0013] A test support computer stores a master copy of the test program, a master copy of the test mask memory, and a complete set of proven test vectors. These are loaded into the appropriate memories before testing commences. A test is performed by running the test program and comparing test vectors generated by the SUT against the proven test vectors. Any mismatch raises a flag which is reported at a given test cycle count. The test result is passed to the test support computer which diagnoses potential causes of any flagged mismatches, and displays recommendations to the test operator for reworking defective components in the system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Preferred embodiments of the invention are described below with reference to the following accompanying drawings.
[0015] [0015]FIG. 1 is a high level block diagram of the test system of the current invention, showing primary data and control flows; and
[0016] [0016]FIG. 2 is a timing diagram showing representative test signal waveforms for both a passing and a failing test event.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] [0017]FIG. 1 shows a high-level block diagram of a test apparatus of the current invention including a test chip 1 and a test support computer 2 connected to the system under test (SUT) 3 . SUT 3 includes digital circuits 4 , analog circuits 5 , and RF circuits 6 . System access port 7 is preferably a high-density connection between SUT 3 and test support computer 2 . This port is preferably used to validate the interconnection circuits of the SUT using continuity-testing circuits typically provided on a plug-in board within test support computer 2 . Similarly, another plug-in board within test support computer 2 may include circuits for testing boundary scan circuits 8 of SUT 3 . Plug-in boards can be used for these tests because the clock rates are typically slower than for functional testing; the test hardware is less demanding and is typically available as a commercial-off-the-shelf (COTS) item. Also, connecting wires or cables can be tolerated at the lower test frequencies. In combination, the continuity and boundary scan tests validate the integrity of the conductive traces and also the placement and orientation of components mounted on the system board. The rest of this description will focus on the more challenging task of functionally testing the SUT at clock rates of 1 GHz and higher.
[0018] Three signal types are tested by test chip 1 in the preferred embodiment. Digital input bus 10 is a collection of digital signals bussed to input pads and input buffers (not shown) of test chip 1 . Similarly analog input bus 11 is a collection of analog signals bussed to test chip 1 . RF inputs 12 are collected at one or more antenna sites on the SUT as shown. Preferably, signals of each type are routed in a manner that protects them from electrical noise sources in the system, typically by providing spatial separation between circuit blocks of different types, and among the signals of a given type.
[0019] Timing circuits 13 on the SUT provide a timing reference (TREF) 14 . In a digital system employing synchronous design TREF 14 may be a digital system clock, with one system cycle represented by one period of the system clock. This is the most common type of system and for the purpose of illustration this is the type of system discussed herein. However, asynchronous designs and other timing methods are possible and are included within the scope of the present invention. TREF 14 is an input to cycle counter 15 which increments every system cycle, and provides a pointer (CCNT) 16 to every system cycle within a test program.
[0020] As a preferred first step in the process of learning correct system behavior, an application program that would run in system processor 17 is augmented with additional instructions to produce a test program. This is a convenient way to generate the first draft of the test program. The application software is typically written in a high level language; both the software and the program language are usually familiar to the system developers. The program is written to thoroughly exercise all of the features and components of the system. It is augmented with additional instructions that generate a test enable signal (TSTEN) 18 to highlight critical system cycles whenever it is judged that system behavior should be captured and tested. The behavior is preferably captured in test vectors. An example of a critical system cycle would be an instruction to read a register in a system component containing a digital variable that has just been calculated or has otherwise just changed to reflect a new result. The selected cycles are combined with TREF 14 to produce a mask memory 19 and also to generate test strobes such as TSTB 20 . The mask memory is a serial memory that contains a 1 for system cycles that are selected as test cycles, and a 0 for all other cycles. In practice the sampling circuits may operate continuously, with only a few of the samples tested. We shall define “sample and test” as a unified sequence that includes both sampling and testing of the sampled input. System behavior is only sampled and tested during test cycles, which are typically a small fraction, perhaps 1% of the total system cycles. Similarly a test strobe 20 is generated only during test cycles, and is referenced to TREF 14 . This preliminary process for generating test vectors may be imprecise because the instruction used to generate TSTEN 18 typically occupies several system cycles. Consequently, too many 1s may be placed in mask memory.. However, a test program developer can easily scan these sequences and cull the number of 1s to create an optimal set. This refinement of the mask memory is typically performed using software running on test support computer 2 .
[0021] A bi-directional bus interface 21 is provided between test support computer 2 and system processor 17 . Interface 21 is used for general communications such as may be required for synchronization, and also for passing test programs and augmented test programs back and forth between SUT 3 and test support computer 2 .
[0022] After the first phase of selecting critical test cycles is complete as outlined above, a preliminary version of mask memory 19 is available in test chip 1 . Bi-directional interface 22 allows the mask image to be passed back and forth between mask memory 19 and test support computer 2 as it is successively refined and tested.
[0023] Other interfaces to test support computer 2 include results bus 23 for reporting test results from the fail memories, and a bi-directional interface 24 to the reference memories. As will be described, the reference memories contain proven test vectors used for comparison with system outputs. As with the test program and the mask memory, it is desirable to pass the contents of the reference memories in and out of test support computer 2 during the process of refining them.
[0024] We shall first examine testing of system behavior represented by digital signals. A core logic block 25 on test chip 1 includes a reference memory 26 , a digital comparator 27 , and a fail memory 28 . Digital input bus 10 is sampled to form a test vector, DVIN, 29 at one input to comparator 27 . The number of bits in test vector DVIN 29 corresponds to the number of digital bits sampled. During test mode, the other input to comparator 27 is provided by reference memory 26 in the form of a proven digital test vector, PDV 30 . During learn mode, digital inputs 10 are sampled and captured in reference memory 26 . If the SUT is fully functional, then the learned test vectors will indicate correct system behavior. This method of learning the correct system behavior can eliminate a lot of work in generating and validating the test vectors by simulation or other means.
[0025] Multiple system prototypes may be used to generate the learned behavior; some will contribute only a portion of the total behavior, others will be used to statistically validate the learned responses. The learned test vectors are transferred to test support computer 2 where they are assembled and saved in a memory block comprising a full set of digital test vectors. For a given test cycle, if the compared vectors DVIN and PDV are the same, then no error flag is raised and no entries are written to fail memory 28 . Conversely, if the two vectors are not the same, comparator 27 will send an error flag for digital signals, DFLG, 31 to fail memory 28 . DFLG 31 will cause CCNT 16 to be saved in fail memory 28 as a pointer to a failed test cycle. It is preferable to store in fail memory 28 the value of CCNT when the failure occurred, plus all the bits of the comparison vector. At least one of these bits will be a zero to indicate that a failure occurred. The location of 0's within the comparison vector may be used by diagnostic software hosted in test support computer 2 to help determine the specific failing component or components, to support subsequent recommendations to the test operator about which components need to be replaced.
[0026] An alternative embodiment of the test architecture will provide the comparison test vector in the appropriate reference memory by sampling a second operating system with known good behavior. The critical requirement is that a known good test vector be provided at the instant of comparison, whether it is predetermined and loaded into reference memory or provided by a parallel operating system.
[0027] Next we shall examine testing of system behavior represented by analog signals. The same core logic block 25 is used in the test path for analog inputs 11 , enumerated as digital comparator 35 , reference memory 36 , and fail memory 37 . An analog to digital converter, ADC, 38 digitizes each waveform of the sampled data and concatenates the digitized words to form a test vector, AVIN, 39 . Again, system behavior can be learned by loading sampled and digitized analog inputs into reference memory 36 and then reading the digital words into test support computer 2 , to create a memory block comprising a full set of analog test vectors. In test mode however, reference memory 36 has been pre-loaded with known good or proven test vectors from test support computer 2 . If a digital comparison produces a mismatch between test vector AVIN 39 . and proven test vector PAV 40 , error flag AFLG 41 for analog signals is sent to fail memory 37 .
[0028] Next we shall examine testing of system behavior represented by RF signals. The same core logic block 25 is used in the test path for radio frequency inputs 12 , enumerated as digital comparator 45 , reference memory 46 , and fail memory 47 . An RF converter, RFC, down-converts each RF signal to a suitable intermediate frequency, IF, and demodulates the signal. The parallel stream of demodulated signals 49 is digitized by analog to digital converter, ADC, 50 , and the digitized words are concatenated to form test vector, RVIN, 51 . Again, system behavior can be learned by loading sampled and digitized RF inputs into reference memory 46 and then reading the digital words into test support computer 2 , to create a memory block comprising a full set of RF test vectors. In test mode however, reference memory 46 has been pre-loaded with known good or proven test vectors from test support computer 2 . If a digital comparison produces a mismatch between test vector RVIN 51 and proven test vector PRV 52 , error flag RFLG 53 for RF signals is sent to fail memory 47 .
[0029] [0029]FIG. 2 shows representative timing of both a passing test event [designated “(A)”] and a failing test event [designated “(B)”]. Waveforms are presented with voltage on the vertical axis and time on the horizontal axis. The timings are shown for a digital input signal and represent just one possible example of how the various edges of TREF could be used to generate test control signals. Since in the preferred embodiment analog and RF signals are converted to digital signals in test chip 1 prior to the comparison event, a similar timing diagram would apply for those signal types as well. TREF 14 is the timing reference previously discussed. It has a system cycle time, T, 55 as shown. TSTB 20 is the test strobe previously discussed. DVIN i 60 is one bit of a digital test vector that has been sampled from digital input bus 10 . PDV i 61 is the corresponding bit of a known good or proven test vector for comparison with DVIN i 60 . DFLG i 62 is the flag used to indicate a failure in bit i of the comparison word, and CCNT 16 is the cycle count. CCNT 16 increments for every system cycle T, 55 . Sequence (A) in FIG. 2 is for a passing test event. A rising edge 63 of TREF causes transition 64 in DVIN i , because the sampled digital signal is high during this test cycle. The compared value PDV i also transitions 65 to a high because the corresponding ith bit of the proven test vector in reference memory 26 is high. CCNT also switches, 66 , in response to rising edge 63 of TREF. The following trailing edge of TREF 67 causes a positive transition 68 in TSTB as shown. TSTB activates the comparison of level 70 of DVIN i with level 71 of PDV i . Since the compared levels are the same, indicating correct system behavior, DFLG i remains low 72 , and the corresponding value of CCNT is not saved in fail memory 28 . Conversely, sequence (B) in FIG. 2 is for a failing test event. The waveforms are similar to those depicted for sequence (A) except for DVIN i and DFLG i . The sampled test vector bit DVIN i is low when it should be high. Thus at edge 79 of TSTB the compared levels 80 of DVIN i and 81 of PDV i are not the same. This causes DFLG i to transition high 82 which in turn causes the value of CCNT 84 to be captured in fail memory 28 , along with the comparison vector having 0's for the failed bit locations.
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The technology and economics of system testing have evolved to the point where a radical change in methodology is needed for effective functional testing of systems at clock rates of 1 GHz and higher. Rather than providing a test fixture to interface between the system under test and an external tester, it is preferable to provide critical testing functions within each electronic system in the form of one or more special-purpose test chips. An architecture is proposed that supports full-speed testing with improved noise margins, and also efficient methods for learning correct system behavior and generating the test vectors. The test program is preferably written using the same programming language as used for the system application.
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This application is a continuation-in-part of U.S. patent application Ser. No. 09/592,398 filed Jun. 13, 2000 now U.S. Pat. No. 6,416,249.
FIELD OF THE INVENTION
This invention relates to apparatus for in situ rejuvenation of asphalt pavement. More particularly this invention relates to a method and apparatus for mixing milled asphalt pavement and rejuvenating fluid in such rejuvenation.
BACKGROUND OF THE INVENTION
Asphalt pavement consists essentially of an aggregate and sand mixture held together with a petroleum based binder, such as asphalt cement (ie. an “asphalt mix”). With continued exposure to sun, moisture, traffic, freezing and thawing, asphalt mix surfaces degrade. The degradation is principally in the binder, rather than the aggregate and sand mixture which makes up the bulk of the asphalt mix. Also, much of the degradation occurs within the top two or three inches of the surface.
Traditionally, worn asphalt pavement was not restored but was instead torn up and replaced with new asphalt mix. This is a costly approach and creates a problem as to what to do with the torn up pavement. Accordingly, techniques and apparatus have been developed for restoring or rejuvenating the top few inches of an asphalt paved surface.
A typical road resurfacing machine has a heater for heating and softening the asphalt pavement surface as it passes along the surface. Following the heater is a “rake” or “scarifier” which breaks up or “scarifies” the softened pavement. The scarified pavement is generally crushed or “milled”, blended with rejuvenating fluid and optionally additional sand or aggregate and redeposited. The redeposited material is spread out and rolled to create a rejuvenated surface comparable in quality to the original surface before degradation.
In order to produce a rejuvenated surface of high quality, it is important to ensure that an appropriate amount of rejuvenating fluid is added. Generally, a core sample or several core samples are initially taken of the surface to be rejuvenated and a desired ratio of rejuvenating material to milled material is analytically determined.
It is also important to thoroughly intermingle the milled material with the rejuvenating material, which will at least include a fluid but may also include additional sand and/or aggregate. In doing so it is important to maintain retention in the mixer while nevertheless maintaining volume throughput at a desired rate.
It is an object of the present invention to provide a method and apparatus for thoroughly blending the milled material with at least the rejuvenating fluid and with any other rejuvenating materials.
SUMMARY OF THE INVENTION
Improvements are provided in an asphalt pavement resurfacing machine having a transport structure, a heater mounted to the transport structure for heating an underlying asphalt pavement surface to form a heated surface, a mill mounted to the transport structure to follow the heater and grind the heated surface to form a milled material and to prepare the underlying surface to a preset depth, a rejuvenating fluid sprayer for introducing a rejuvenating fluid to the milled material and a mixer for blending the milled material with the rejuvenating fluid. According to the improvement, the mill is provided with at least two outlets of predetermined breadth. A respective height monitor is provided at each of the two outlets for determining the height of the milled material being discharged from each of the outlets. Respective forward facing inlets are provided into the mixer for receiving milled material from each outlet as the machine is advanced in a travel direction. A respective rejuvenating fluid sprayer is provided for spraying rejuvenating fluid on the milled material emanating from each outlet. The mixer may be a pug mill having a housing which has a downwardly facing bottom opening. The mixer may further have a plurality of paddles extending radially from a pug mill shaft mounted within the housing, rotatable with the shaft and orientated to blend the rejuvenating fluid with the milled material and to direct a blended material so formed toward at least one discharge outlet facing rearwardly relative to a travel direction of the resurfacing machine.
Windrow guides may be provided between the mill and the mixer to maintain windrow breadth and to guide the windrows into the mixer.
The improved machine may further comprise a control and processing station which receives input from each height monitor and from a resurfacing machine speed monitor to determine a discharge rate of milled material from each outlet and cause each sprayer to dispense rejuvenating fluid on the milled material at a desired rate based on the discharge rate.
A method is provided for asphalt paved road surface rejuvenation utilizing a structure having a heater, a mill and a mixer carried by a transport structure. The method comprises the steps of:
i) passing the heater over the road surface to heat and soften the road surface and form a preheated surface;
ii) passing the mill over the preheated surface and milling the preheated surface to loosen the preheated surface to a desired depth thus forming a milled material;
iii) discharging the milled material from opposite ends of the mill in respective windrows of known breadth;
iv) measuring windrow height and rate of advance of the transport structure;
v) comparing the breadth in step (iii) with the height and rate of advance in step (iv) to determine volume throughput;
vi) adding a rejuvenating fluid to each windrow at a dosage rate based on a desired weight percentage and the volume throughput;
vii) passing the mixer over the windrows and receiving the windrows through respective openings in the mixer;
viii) blending the rejuvenating fluid with the milled material in the mixer to form a blended mixture; and
ix) discharging the blended mixture from the mixer.
The mixer may be a pug mill extending transversely across the support structure and having sufficient breadth to capture the windrows simultaneously.
The pug mill may be operated in an inverted arrangement in which an open face thereof is adjacent the surface to utilize the surface as a bottom thereto.
DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention are described below with reference to the accompanying drawings in which:
FIG. 1 is a schematic representation of an asphalt resurfacing machine according to the present invention;
FIG. 2 is an enlarged view of the rearward portion of the asphalt resurfacing machine of FIG. 1; and,
FIG. 3 is an exploded view of a mixer according to the present invention;
FIG. 4 is a schematic plan view from above of an alternate embodiment arrangement of the milling and mixing stages; and,
FIG. 5 is a front elevation corresponding to FIG. 4 .
DESCRIPTION OF PREFERRED EMBODIMENTS
An asphalt pavement resurfacing machine is generally indicated by reference 10 in FIG. 1 . The resurfacing machine 10 travels in a path of travel indicated by arrow 12 . The resurfacing machine 10 has a transport structure 11 to which its various components are mounted. The transport structure 11 is basically a support frame having wheels or tracks 54 . A power plant 14 at the front of the transport structure 11 is provided to drive the apparatus and typically includes an engine and a hydraulic system.
Behind the power plant 14 and also mounted on the transport structure 11 is a heater 16 which includes numerous burners and associated plumbing for heating an asphalt paved surface 18 upon which the resurfacing machine 10 travels. A propane (or other combustible fuel) tank 20 and a combustion blower 22 serve the burners in the heater 16 . The heater 16 directs heat at the asphalt surface 18 to cause softening of an upper part of the asphalt paved surface 18 .
The softened surface 18 may be initially dislodged by a raking device, generally indicated by reference 30 , mounted to the transport structure 11 , and which follows the heater 16 . The raking device 30 has rakes which dislodge the heated surface 18 . The raking device 30 may include main rakes 32 and extension rakes 34 , the extension rakes 34 performing a similar function to the main rakes 32 , but to the outside edges. The main rakes 32 break up material around manholes where a main mill 36 behind the raking device 30 cannot run.
The main mill 36 which is mounted to the transport structure 11 behind the raking device 30 grinds up the material dislodged by the rakes, levels the underlying surface and prepares the surface to a preset depth. Extension mills 38 ahead of the main mill 36 perform a similar function, but process outer material typically from 10 to 15 feet to each side of the resurfacing machine 10 and move it to a central part of the resurfacing machine 10 where it is subsequently processed by the main mill 36 .
In some applications the apparatus may be operated without a raking device 30 , in which case the softened surface 18 will be directly ground by the main mill 36 and any extension mills 38 .
A pug mill 100 , also mounted to the transport structure 11 , follows the main mill 36 and acts as a mixer for blending the processed material from the main mill 36 with rejuvenating fluid from a tank 42 . The pug mill 100 is described in more detail below.
Blended material 46 from the pug mill 100 is picked up by a scalping conveyor 44 which deposits the blended material 46 in a heated holding hopper 48 . The holding hopper 48 keeps the blended material 46 hot until it is needed. The holding hopper 48 may be filled through its top with material for start ups or if additional material is needed. The holding hopper 48 may also be dumped if required or at the end of a day's operation.
A screed 50 follows the asphalt rejuvenating apparatus 10 and may be a unit such as typically found on an asphalt paver. The screed 50 lays, spreads and slightly compacts the blended material 46 for final rolling.
A water system 52 may be provided to supply cooling water to the front and rear tires or tracks 54 .
An operator 56 operates a control and processing station 58 . From initial core samples the amount of rejuvenating fluid, sand and aggregate required to bring the asphalt paved surface 18 up to a suitable specification can be determined. The operator 56 can input and monitor the amounts of rejuvenating fluid, sand and aggregate being added.
A sand/aggregate bin 60 precedes the asphalt pavement resurfacing machine 10 . The sand/aggregate bin 60 may be attached to the apparatus 10 or attached to a separate machine (not shown) running in front thereof. Sand/aggregate is metered at a specific rate which is a function of ground speed and specification requirements.
The mixer or “pug mill” 100 is shown in more detail in the exploded view of FIG. 3 . The mixer 100 has a first stage 102 which includes a housing or “first stage shell” 104 which is substantially enclosed but for a downwardly facing bottom opening 106 . The first stage shell 104 also has an inlet opening 108 through a forward face thereof which faces in the travel direction 12 of the transport structure 11 and a rearwardly facing discharge outlet.
The first stage 102 in use is placed in close proximity to the underlying surface to form a substantially enclosed chamber with the underlying surface acting as a bottom part of the first stage 102 . A hydraulic cylinder 120 and parallel bar linkage 122 in FIG. 2 mount the mixer 100 to the transport structure 11 and control the placement of the first stage 102 .
A first stage shaft 110 is mounted to the first stage shell 104 for rotation about a first stage shaft axis 112 which extends transversely relative to the travel direction 12 . A plurality of paddles 114 extend from the first stage shaft 110 in a direction generally radial relative to the first stage shaft axis 112 . The paddles 114 are rotatable with the first stage shaft 110 to blend the milled material with the rejuvenating fluid. The paddles 114 are aligned to direct the blended material ( 46 in FIGS. 1 and 2) generally in the direction of arrows 116 toward a discharge outlet 118 . The discharge outlet 118 faces rearwardly relative to the travel direction 112 and the blended material 46 is discharged therefrom as the resurfacing machine 10 moves in the forward direction 12 .
A rotator for rotating the first stage shaft 110 may take a variety of forms. For example, as illustrated in FIG. 2, a motor 121 may be mounted to the pug mill 102 and rotationally coupled to the first stage shaft 110 by a motor sprocket 123 mounted to the motor 121 , a first stage shaft sprocket 124 mounted to the first stage shaft 110 and a roller chain 126 extending therebetween. It will be appreciated by those skilled in driver apparatus for such machinery that the rotator could take a variety of other forms. For example, a direct gear drive may be used instead of the sprocket and chain drive illustrated, or the motor 120 could be directly coupled to the first stage shaft 110 .
According to one embodiment, the blended material is not be immediately discharged from the first stage discharge outlet 118 , but rather is further blended in a second stage 130 which follows the first stage 102 . The second stage receives blended material from the first stage discharge outlet 118 . The second stage 130 has a downwardly opening second stage shell 132 , which may be integral with and extend from the first stage shell 104 . A second stage shaft 134 is mounted in the second stage shell 132 for rotation about a second stage shaft axis 136 .
A plurality of paddles 138 extend generally radially from the second stage shaft 134 and are rotatable therewith to further blend the blended material 46 . The paddles 138 are oriented to direct the blended material 46 in the direction of arrows 140 toward the second stage discharge opening 142 .
The second stage discharge opening 142 faces rearwardly relative to the travel direction 12 . The blended material is preferably discharged from the second stage discharge opening 142 in a windrow of fixed breadth determined by the breadth of the second stage discharge opening 142 .
A rotator for rotating the second stage shaft 134 may, as illustrated in FIG. 2, be a second stage shaft sprocket 144 mounted to the second stage shaft 110 and about which the roller chain 126 extends.
Rejuvenating fluid may be added at various points in the resurfacing process. Preferably rejuvenating fluid should be added to the milled material prior to its entering the pug mill 100 . This may be accomplished by adding rejuvenating fluid at or before the main mill 36 or ahead of the pug mill inlet 108 . The latter arrangement is illustrated in FIG. 3 which shows a spray bar 150 for directing rejuvenating fluid at or ahead of the pug mill inlet 108 .
An alternate embodiment of the present invention is illustrated in FIGS. 4 and 5. According to the alternate embodiment, a main mill 236 is configured to discharge milled material through respective outlets 270 and 272 at opposite ends thereof in respective windrows 274 and 276 . The outlets 270 and 272 are of known width and a respective ultrasonic scanner or other measuring device 278 and 280 is mounted to a convenient location such as the transport structure 11 or the mill 236 to monitor the height of the windrows 274 and 276 . Windrow height data is sent to the control and processing station 58 which also monitors the speed of the resurfacing machine to calculate, preferably for each of the windrows 274 and 276 , the volume discharge rate and the requisite addition of rejuvenating fluid.
Test results suggest that the measuring devices 278 and 280 are preferably radar devices such as the SITRANS LR 400 (TM) produced by Siemens Corporation. The SITRANS LR 400 utilizes 24 GHz radar for level measurement of solids or liquids. Radar measuring units appear to be more accurate than ultrasonic scanners and less prone to failure than potentiometer-based devices.
As the main mill 236 in the alternate embodiment has two outlets 270 and 272 , a correspondingly designed pug mill 200 is required. The pug mill 200 is a single stage design having a single long pug mill shaft 210 mounted within a pug mill shell or, housing 204 . The pug mill housing has respective inlet openings 208 and 209 at opposite ends thereof aligned with the outlets 270 and 272 of the main mill 236 . The inlet openings 208 and 209 receive the windrows 274 and 276 respectively.
In order to maintain the breadth of the windrows 278 and 280 , windrow guides 290 may be provided which extend from opposite sides of the outlets 270 and 272 of the main mill 236 . Corresponding guides 292 may be provided which extend from the inlet openings 208 and 209 of the pug mill 200 . Preferably one of the windrow guides 290 and 292 will be metal, and the other an elastarmeric material such as rubber to maintain a reasonably good seal therebetween. The windrow guides 290 and 292 assist both in maintaining a constant windrow breadth and in ensuring that the entire windrow is directed into the pug mill 200 . Maintaining the breadth enhances the accuracy of the volume throughput measurement based on the height measurement.
Paddles 214 extend radially from the pug mill shaft 210 to blend the milled material with rejuvenating fluid. Preferably the rejuvenating fluid is sprayed on the windrows 274 and 276 in metered amounts by the sprayers 250 as calculated by the control and processing station 58 . The blended material is directed by the paddles 214 for discharge through a rearwardly facing discharge opening 242 .
An advantage of adding rejuvenating fluid after milling is that the dislodged road surface has a further opportunity to cool which has the benefit of reducing the amount of smoke generated by the resurfacing machine 10 . Additionally, providing two windrows of material from the main mill 236 can significantly increase production rate by a factor of about two (2).
A further advantage of the alternate embodiment of FIGS. 4 and 5 is enhanced response time (or reduced lag). Monitoring throughput of milled material at about the same point as the addition of rejuvenating fluid permits quick response and a high level of accuracy. In the first embodiment described above, a delay or lag of at least four (4) to five (5) feet would occur between the monitoring of volume throughput and the addition of rejuvenating fluid. While this is still a vast improvement over earlier systems, it does generate some error in uneven surfaces when fluctuations in the pug mill output may not coincide with fluctuations in the amount of surface being milled.
As in the first embodiment described above having a two stage pug mill 100 , the shell 204 of the long single stage pug mill 200 is substantially enclosed but for a downwardly facing bottom opening 206 , the inlet openings 208 and 209 and the discharge opening 242 . The bottom opening 206 in use would be held in close proximity to the underlying surface for the underlying surface 18 to act as a bottom of the pug mill 200 .
The above description is intended in an illustrative rather than a restrictive sense. Variations to the specific embodiments described may be apparent to those skilled in such apparatus and processes without departing from the spirit and scope of the invention as defined by the claims set out below.
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A method and apparatus are provided for in situ rejuvenation of asphalt pavement. The apparatus and method provide for heating the underlying surface to form a preheated surface, passing a mill over the preheated surface and milling the preheated surface to loosen the preheated surface to a desired depth and discharging the milled material from opposite ends of the respective windrows of known breadth. Windrow height is measured as is rate of advance of the transport structure to determine a volume throughput. Rejuvenating fluid is added to each windrow at a dosage rate based on a desired weight percentage and the volume throughput. A mixer is passed over the windrows and receives the windrows through respective openings at either end thereof. The mixer also blends the rejuvenating fluid with the milled material and forms a blended mixture which is discharged from the mixer. The mixer may be a pug mill operated in an inverted arrangement utilizing the road surface as a bottom thereto.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 12/756,897 filed Apr. 8, 2010, now U.S. Pat. No. 8,041,500, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
The present application relates to hydrogen-rich reformate and more particularly, to preventing or mitigating engine surge.
BACKGROUND AND SUMMARY
Engine surge (one example of engine combustion instability) includes oscillations in engine torque. Such oscillations in engine torque result in reduced drive feel.
In one approach a wheel brake pressure is controlled in response to measurements of engine torque. By increasing wheel brake pressure on one or more wheels in response to engine surge, vehicle traction may be improved during surge. Consequently, drivability may be improved.
The inventors herein have recognized issues with the above described approach. Controlling wheel brake pressure does not address the underlying engine conditions leading to engine surge. Without addressing the underlying engine conditions, engine surge may persist.
Consequently, systems, devices and methods are disclosed for engine control for a reformate engine. As one example, a method for an engine includes reforming fuel at a catalyst into reformate; and adjusting a supply of reformate to a cylinder of the engine in response to an engine surge, the surge including an oscillation in torque produced by the engine. The fuel to be reformed may include, for example, ethanol, another alcohol, gasoline, diesel fuel, or a combination of fuels.
One advantage of the example is that surge may be mitigated. Further, the present example allows for a smaller and lower cost reformer, if desired, because the supply of reformate to the engine cylinder is adjusted in response to surge, rather than continuously maintained at an unnecessarily high level during engine operation. By adjusting reformate in combination with further vehicle operating parameters, like charge dilution, wheel brake and spark timing, engine surge is mitigated while achieving increased engine efficiency due to aggressive use of lean burn, exhaust gas recirculation (EGR), and/or variable valve timing (VVT).
It will be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description, which follows. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined by the claims that follow the detailed description. Further, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic representation of a vehicle illustrating example locations wherein longitudinal acceleration sensors may be placed on the vehicle.
FIG. 2 shows a schematic diagram of an example internal combustion engine.
FIG. 3 shows a block diagram of systems and devices related to sensing acceleration in a vehicle.
FIG. 4 illustrates an example routine for adjusting a supply of reformate to a cylinder of the engine in response to an engine surge.
FIG. 5 illustrates an example subroutine for determining a feasibility of increasing a percentage of reformate in an example engine cylinder.
FIG. 6 illustrates an engine map with respect to engine speed-load.
DETAILED DESCRIPTION
Initially, an example vehicle, including an engine and further systems, such as a reformate system and a stability control, are described with respect to FIGS. 1 and 2 . FIG. 3 is then discussed, which shows a block diagram further describing some of the systems and devices related to sensing acceleration in a vehicle. A first example routine is described with respect to FIG. 4 as one example of a method for controlling reformate use in an engine, such as reformed ethanol. Further, a subroutine shown in FIG. 5 is discussed as one example of a method for determining a feasibility of increasing a percentage of reformate in an example charge.
FIG. 1 is a schematic illustration of a vehicle 150 , and FIG. 2 is a schematic illustration of a system 200 that may be included in the vehicle 150 . The vehicle 150 and the system 200 may have one or more longitudinal acceleration sensors (which are all example accelerometer sensors) in accordance with various embodiments. Various numbers and configurations of acceleration sensors may be used. One or more longitudinal acceleration sensors that may already be present on the vehicle 150 may be used, or one or more longitudinal acceleration sensors may be added to the vehicle 150 . Three longitudinal acceleration sensors are illustrated in FIGS. 1 and 2 . One longitudinal acceleration sensor 202 may be included as part of a stability control 204 for the vehicle 150 . The stability control 204 may be an electronic stability control (ESC) or a rollover stability control (RSC), or the like. Another longitudinal acceleration sensor (e.g., 206 of FIG. 3 ) may be included as part of an airbag system 208 for the vehicle 150 . Another longitudinal acceleration sensor 210 may be an added to the vehicle 150 .
The processor 212 may be operatively coupled with an engine controller 12 . The system 200 may include an ignition system 88 that may be configured to provide an ignition spark to combustion chamber 30 via spark plug 92 in response to a spark advance signal SA, or a spark retard signal SR from engine controller 12 , under select operating modes, and in accordance with instructions from the processor 212 .
Alternatively, the processor 212 , and/or functions described herein may be included as part of the engine controller 12 , and may in particular be included as part of a microprocessor unit (CPU) 102 .
Engine controller 12 is shown in FIG. 2 as a microcomputer, including microprocessor unit 102 , input/output ports 104 , an electronic storage medium for executable programs and calibration values shown as read only memory chip 106 in this particular example, random access memory 108 , keep alive memory 110 , and a data bus.
Engine controller 12 may receive various signals from sensors coupled to engine 10 , in addition to those signals previously, and hereinafter, discussed, including measurement of inducted mass air flow (MAF) from mass air flow sensor 120 ; engine coolant temperature (ECT) from temperature sensor 112 coupled to cooling sleeve 114 ; a profile ignition pickup signal (PIP) from Hall effect sensor 118 (or other type) coupled to crankshaft 40 ; throttle position (TP) from a throttle position sensor 62 ; a measurement of reformer tank pressure from pressure sensor 85 ; and a measurement of reformer tank temperature from temperature sensor 87 ; and absolute manifold pressure signal, MAP, from sensor 122 . Engine speed signal, RPM, may be generated by engine controller 12 from signal PIP. Barometric pressure may also be sensed (sensor not shown) for processing by controller 12 .
FIG. 2 illustrates one cylinder of multi-cylinder engine 10 , which is included in a propulsion system of vehicle 150 . Engine 10 may be controlled at least partially by a control system including the engine controller 12 and by input from a vehicle operator 132 via an input device 130 . In this example, input device 130 includes an accelerator pedal and the pedal position sensor 134 for generating a proportional pedal position signal PP. Engine 10 includes combustion chamber 30 and cylinder walls 32 with piston 36 positioned therein. Piston 36 may be coupled to crankshaft 40 so that reciprocating motion of the piston is translated into rotational motion of the crankshaft. Crankshaft 40 may be coupled to at least one drive wheel of a vehicle via an intermediate transmission system. Further, a starter motor may be coupled to crankshaft 40 via a flywheel to enable a starting operation of engine 10 . Combustion chamber 30 is shown communicating with intake manifold 44 and exhaust manifold 48 via respective intake valve 52 and exhaust valve 54 .
In this example, intake valve 52 and exhaust valves 54 may be controlled by cam actuation via respective cam actuation systems 51 and 53 . Cam actuation systems 51 and 53 may each include one or more cams and may utilize variable valve timing (VVT) which includes one or more of cam profile switching (CPS), variable cam timing (VCT), and/or variable valve lift (VVL) systems that may be operated by controller 12 to vary valve operation. The position of intake valve 52 and exhaust valve 54 may be determined by position sensors 55 and 57 , respectively. In alternative embodiments, intake valve 52 and/or exhaust valve 54 may be controlled by electric valve actuation (EVA). For example, cylinder 30 may alternatively include an intake valve controlled via electric valve actuation and an exhaust valve controlled via cam actuation including CPS and/or VCT systems.
Intake manifold 44 is also shown coupled to the engine cylinder having fuel injector 66 coupled thereto for delivering liquid fuel in proportion to the pulse width of signal FPW from controller 12 . Fuel is delivered to fuel injector 66 by a fuel system including fuel tank 91 , fuel pump (not shown), fuel lines (not shown), and fuel rail (not shown). The engine 10 of FIG. 1 is configured such that the fuel is injected directly into the engine cylinder, which is known to those skilled in the art as direct injection. Alternatively, liquid fuel may be port injected. Fuel injector 66 is supplied operating current from driver 68 which responds to controller 12 . In addition, intake manifold 44 is shown communicating with optional electronic throttle 64 . In one example, a low pressure direct injection system may be used, where fuel pressure can be raised to approximately 20-30 bar. Alternatively, a high pressure, dual stage, fuel system may be used to generate higher fuel pressures.
Gaseous fuel may be injected to intake manifold 44 by way of fuel injector 89 . In another embodiment, gaseous fuel may be directly injected into cylinder 30 . One example of gaseous fuel is reformate. Gaseous fuel is supplied to fuel injector 89 from storage tank 93 by way of pump 96 and check valve 82 . Pump 96 pressurizes gaseous fuel supplied from fuel reformer 97 in storage tank 93 . Check valve 82 limits flow of gaseous fuel from storage tank 93 to fuel reformer 97 when the output of pump 96 is at a lower pressure than storage tank 93 . Fuel reformer 97 includes catalyst 72 and may further include optional electrical heater 98 for reforming liquid fuel (such as ethanol) supplied from fuel tank 91 . Fuel reformer 97 is shown coupled to the exhaust system downstream of catalyst 70 and exhaust manifold 48 . However, fuel reformer 97 may be coupled to exhaust manifold 48 and located upstream of catalyst 70 . For example, fuel reformer 97 may use a catalyst and exhaust heat to drive an endothermic dehydrogenation of alcohol supplied by fuel tank 91 to promote fuel reformation.
Distributorless ignition system 88 provides an ignition spark to combustion chamber 30 via spark plug 92 in response to controller 12 . Universal Exhaust Gas Oxygen (UEGO) sensor 126 is shown coupled to exhaust manifold 48 upstream of catalytic converter 70 . Alternatively, a two-state exhaust gas oxygen sensor may be substituted for UEGO sensor 126 .
Converter 70 can include multiple catalyst bricks, in one example. In another example, multiple emission control devices, each with multiple bricks, can be used. Converter 70 can be a three-way type catalyst in one example. Further, in the present example engine 10 includes an EGR conduit 80 to direct exhaust gases, upstream of converter 70 and/or downstream of converter 70 back to the intake manifold 44 . In further examples, EGR conduit 80 may not be coupled to intake 42 upstream of throttle 64 . Further, EGR conduit 80 includes an EGR valve 81 which meters flow through the EGR conduit, and may be a continuously variable valve or a two position on/off valve.
In a preferred aspect of the present description, engine position sensor 118 produces a predetermined number of equally spaced pulses every revolution of the crankshaft from which engine speed (RPM) can be determined. In one embodiment, the stop/start crank position sensor has both zero speed and bi-directional capability. In some applications a bi-directional Hall sensor may be used, in others the magnets may be mounted to the target. Magnets may be placed on the target and the “missing tooth gap” can potentially be eliminated if the sensor is capable of detecting a change in signal amplitude (e.g., use a stronger or weaker magnet to locate a specific position on the wheel). Further, using a bi-dir Hall sensor or equivalent, the engine position may be maintained through shut-down, but during re-start alternative strategy may be used to assure that the engine is rotating in a forward direction.
In some embodiments, the engine may be coupled to an electric motor/battery system in a hybrid vehicle. The hybrid vehicle may have a parallel configuration, series configuration, or variation or combinations thereof.
During operation, each cylinder within engine 10 typically undergoes a four stroke cycle: the cycle includes the intake stroke, compression stroke, expansion stroke, and exhaust stroke. During the intake stroke, generally, the exhaust valve 54 closes and intake valve 52 opens. Air is introduced into combustion chamber 30 via intake manifold 44 , and piston 36 moves to the bottom of the cylinder so as to increase the volume within combustion chamber 30 . The position at which piston 36 is near the bottom of the cylinder and at the end of its stroke (e.g. when combustion chamber 30 is at its largest volume) is typically referred to by those of skill in the art as bottom dead center (BDC). During the compression stroke, intake valve 52 and exhaust valve 54 are closed. Piston 36 moves toward the cylinder head so as to compress the air within combustion chamber 30 . The point at which piston 36 is at the end of its stroke and closest to the cylinder head (e.g. when combustion chamber 30 is at its smallest volume) is typically referred to by those of skill in the art as top dead center (TDC). In a process hereinafter referred to as injection, fuel is introduced into the combustion chamber. In a process hereinafter referred to as ignition, the injected fuel is ignited by known ignition means such as spark plug 92 , resulting in combustion. During the expansion stroke, the expanding gases push piston 36 back to BDC. Crankshaft 40 converts piston movement into a rotational torque of the rotary shaft. Finally, during the exhaust stroke, the exhaust valve 54 opens to release the combusted air-fuel mixture to exhaust manifold 48 and the piston returns to TDC. Note that the above is shown merely as an example, and that intake and exhaust valve opening and/or closing timings may vary, such as to provide positive or negative valve overlap, late intake valve closing, or various other examples.
Turning now to FIG. 3 , processor 212 , stability control 204 , airbag system 208 , and longitudinal acceleration sensor 210 are shown in further detail. Example spark timing adjustments and charge reformate concentration adjustments may occur upon recognizing a steady state of the vehicle while the vehicle is in operation on a driving surface. The system 200 may include various sensors, in addition to the one or more longitudinal acceleration sensors 202 , 206 , 210 that may be configured to recognize the steady state. For example, a wheel position sensor 300 may be coupled to the processor 212 , and configured to sense a wheel position that is substantially unchanged for more that a predetermined amount of time; an accelerator position sensor 302 may be coupled to the processor 212 , and configured to sense an accelerator position being substantially unchanged for a predetermined length of time; a lateral acceleration sensor 304 may be coupled to the processor 212 , and configured to sense changes in lateral acceleration being below a predetermined threshold for more than a predetermined amount of time; and a vehicle yaw sensor 306 may be coupled to the processor 212 , and configured to sense changes in yaw of the vehicle being below a predetermined threshold for more than a predetermined amount of time. The accelerator position sensor 302 may be the same, or different than the pedal sensor 134 discussed above.
In the present example, an additional longitudinal acceleration sensor 206 is included as part of an airbag system 208 for the vehicle 150 . Another longitudinal acceleration sensor 210 may be added to the vehicle 150 . Each of the longitudinal sensors may be coupled with a processor 212 . The processor 212 may be configured to affect increasing or decreasing a percentage of reformate in a charge of air and fuel flowing to one or more example engine cylinders based on an output from one or more of the longitudinal acceleration sensors 202 , 206 , 210 . Further processor 212 may be configured to advance or retard spark timing of an internal combustion engine 10 configured to power the vehicle 150 . The processor 212 may further be configured to effect a spark timing adjustment of the engine toward a peak torque timing.
In the present example, the processor 212 includes a logic unit 214 configured to adjust charge reformate concentration, as discussed above. Further, logic unit 214 may be configured to output a spark timing control signal to the engine controller 12 to adjust the spark timing of the internal combustion engine 10 of the vehicle 150 in a first direction. The logic unit 214 may be further configured for further adjusting the spark timing in the first direction in the case of a positive acceleration or to adjust the spark timing in a second direction in the case of a negative acceleration. The processor 212 may also include an input/output module 216 configured to receive a signal from the longitudinal acceleration sensor and configured to pass the signal to the logic unit 214 .
Turning now to FIG. 4 , a routine 400 is shown. Routine 400 may be a set of instructions on a read-only memory included in an example controller. Routine 400 may be carried out in an example vehicle (e.g. 150 described above) including an engine, a catalyst for reforming liquid fuel into reformate and one or more accelerometers. Further, routine 400 in may be included in a method, the method including adjusting a supply of reformate to a cylinder of the engine in response to an engine surge, the surge including an oscillation in torque produced by the engine, an accelerometer sensor indicating the oscillation in torque.
In the present example, it will be appreciated that measurements of engine conditions and parameters are assumed to take place when needed or be stored in a memory readily accessible to routine 400 . Engine conditions and parameters include valve timing, engine coolant temperature, acceleration along one or more axis, air to fuel ratio, percentage opening of an example EGR valve, etc.
In the present example, routine 400 begins at 410 , 410 including determining if an engine is surging. In one example, an acceleration is detected by one or more longitudinal acceleration sensors. The example acceleration may be oscillating, as a result of oscillating torque brought on by surge. Further, 410 may include band pass filtering an acceleration signal to frequencies above and below a surge window of frequencies. In some examples, amplitudes, intensities, and/or a strength of frequencies in the surge window above a surge threshold determines that there is surge (e.g., the example engine is in a surge state). In the present example, if surge is not present, routine 400 ends.
When routine 400 ends the example engine may continue operating nominally. In this way, a method including routine 400 may include a first operating mode of supplying a first charge reformate concentration to a cylinder in the engine during a nominal engine combustion state.
If engine surge is present, routine 400 continues to optionally apply a wheel brake at 412 or to determine the feasibility of increasing a percentage of reformate entering one or more engine cylinders at 414 . In this way, routine 400 includes a second mode. The second mode may further include supplying a second charge reformate concentration to the cylinder in the engine, the second charge reformate concentration greater than the first charge reformate concentration (e.g., at 418 ). The second mode also includes increased engine surge as compared to the first mode, discussed above. The second mode may include an engine surge state monitored by an example accelerometer sensor coupled in an example vehicle body.
In further examples, 410 includes more generally, determining if combustion is stable. Such further examples may include one or more determinations based on charge motion, dilution, knock detection, a compressor speed (such as in a turbocharger or supercharger), MAP, MAF, etc. In such examples, if combustion is stable, routine 400 ends.
Continuing with routine 400 , as discussed above in some examples after 410 the routine includes at 412 applying a wheel brake to one or more wheels of the example vehicle. Further 412 may include increasing pressure to the example wheel brake, selectively and/or repeatedly. Further, applying the wheel brake may be done without a request from an operator to do so. Applying the wheel brake in response to engine surge or combustion instability is well known to those of skill in the art and is optional in routine 400 , hence the dashed line at 412 . After 412 and 410 , routine 400 may continue to 414 .
After 412 or in response to determining that engine surge is present at 410 , routine 400 continues to 414 which includes determining if increasing a percentage of reformate in one or more cylinders of the engine is feasible. 414 may include determining if there is enough reformate available. Routine 500 , discussed below with respect to FIG. 5 , is one example of determining if increasing charge reformate concentration is feasible.
If at 414 , routine 400 determines that it is feasible to increase charge reformate concentration, then routine 400 continues to 418 to increase the percentage of reformate in a charge entering at least one example engine cylinder. Optionally, routine 400 may include reforming liquid fuel at the example catalyst into reformate at 416 before continuing to 418 . 416 is in dashed lines to indicate its optional nature. By reforming liquid fuel at the catalyst before increasing the percentage of reformate in charge entering an example engine cylinder at 418 , routine 400 may ensure that reformate in a storage tank stays above a reformate threshold, being a quantity of reformate desired for nominal operation of the engine.
Continuing with routine 400 , in the present example 418 includes increasing the supply of reformate to the cylinder of the engine in response to surge. In some examples, increasing the percentage of reformate includes incrementing an amount of reformate injected into an intake manifold and/or an example engine cylinder. In further examples, 418 includes maintaining a consistent air to fuel concentration and therefore an amount of non-reformate fuel injected into the intake manifold and/or the engine cylinder is decremented or decreased. After the percentage of reformate is increased, routine 400 ends.
If at 414 , routine 400 determines that it is not feasible to increase charge reformate concentration, and then routine 400 continues to 420 . 420 includes improving combustion. In the present example, improving combustion includes decreasing charge dilution, (e.g., via reducing EGR, advancing or retarding variable valve timing such as VCT, and reducing lean burn) and/or advancing or retarding spark timing. In additional examples, 420 includes further actions to increase charge combustibility.
Additionally at 420 , combustion may be improved via adjusting charge dilution or spark timing. Engine conditions may be adjusted enough at 420 to lead to probable stable combustion during the next ignition event in the example engine. However, in further examples charge dilution and/or spark timing may be adjusted, but intentionally not enough to lead to probable stable combustion during the next ignition event. In such example, routine 400 includes 428 , discussed below.
In the present example, improving combustion at 420 includes determining if an engine speed-load is above first s-l threshold and the engine speed-load is below second s-l threshold at 422 . 422 is one example of determining a condition of the example engine (e.g., as discussed in further detail below, with respect to FIG. 6 ). In a first condition charge dilution may be adjusted (e.g., at 424 ). In a second condition, spark timing may be adjusted (e.g., at 426 ). In further examples, both spark timing and charge dilution may be adjusted. The condition of the engine, such as a high engine speed and high engine load, may lead to a preferred or effective set of actions for improving combustion.
In the present example, if the engine has a speed-load above a first s-l threshold and below second s-l threshold at 422 , routine 400 continues to 424 to reduce charge dilution. Reducing charge dilution includes adjusting VVT, an EGR valve, etc. In further examples of routine 400 , if the example engine has a speed-load above a first s-l threshold and below second s-l threshold, the engine may additionally or alternatively adjust spark timing at 424 .
If the engine has a speed-load below a first s-l threshold or above second s-l threshold at 422 , routine 400 continues to 426 to adjust spark timing. Adjusting spark timing at 426 includes adjusting toward a best torque or away from a best torque. Adjusting timing at 426 includes adjusting timing based on feedback from one or more example longitudinal acceleration sensors to minimize engine surge.
After either 426 or 424 , routine 400 may optionally continue to 428 . In further examples of routine 400 , the routine may end after either 426 or 424 .
428 includes determining the feasibility of increasing the percentage of reformate in the charge in one or more engine cylinders, as described above with respect to 414 . The 428 is shown in dashed lines to indicate its optional inclusion in routine 400 . If increasing a percent of reformate is feasible, routine 400 continues to 416 to reform liquid fuel into reformate (optionally) or routine 400 continues directly to 418 to increase reformate percentage in a charge, as described above. If not, routine 400 ends.
By inclusion of 428 , routine 400 includes adjusting at least one of charge dilution level and/or spark timing in combination with increasing the supply of reformate to the cylinder of the engine. In further examples, where 428 is not included, and routine 400 may repeatedly run to carry out continuous control of reformate concentration, charge dilution and spark timing.
Additional examples of routine 400 may include decreasing the supply of reformate to the cylinder in response to a dissipation of engine surge, where the dissipation of engine surge includes engine torque oscillations in a surge window below a surge threshold.
By inclusion of 422 and 414 , routine 400 may include determining a condition of an example engine to effect how to response to engine surge. In this way, routine 400 includes a method for the engine including during a first condition, adjusting charge dilution in response to engine surge, the first condition including a speed-load above a first s-l threshold and the speed-load also below a second s-l threshold, during a second condition, adjusting spark timing in response to engine surge and during a third condition, adjusting reformate delivered to the engine in response to engine surge, the third condition including at least one of a reformate amount above a reformate threshold and a rate of reformate production above a production threshold. Engine surge may include torque oscillations indicated by an example longitudinal acceleration sensor, as discussed above.
Further, reformate delivered to the engine may be adjusted before adjusting spark timing or charge dilution are adjusted (e.g., by repeated iterations of routine 400 ). Further still, charge dilution may be adjusted before spark timing (e.g., via repeated iterations of routine 400 and at 420 ) and additionally, reformate delivered to the engine in response to engine surge may be adjusted after adjusting at least one of charge dilution and spark timing (e.g., at 420 and then at 428 and then at 418 ).
One advantage of routine 400 is that the feedback controls described above allow a smaller and cheaper reformer, because reformate concentration is adjusted in response to surge. Further, surge is mitigated and engine efficiency may be improved due to aggressive use of lean burn, EGR and/or VCT.
Turning now to FIG. 5 , a routine 500 is illustrated for determining if increasing charge reformate concentration is feasible. Routine 500 is one example of a subroutine included in routine 400 at 414 and optionally again at 428 . As discussed above, with respect to routine 400 , routine 500 may be a set of instructions on a read-only memory and be implemented on an example engine, including a reformate catalyst and an accelerometer.
Routine 500 starts at 510 , which includes determining if a reformate amount is above a reformate threshold. The reformate amount in the present example is a quantity of reformate in an example gaseous fuel storage tank. The reformate threshold may be a mass, pressure or a volume. Inclusion of 510 is one example of how a method may increase the supply of reformate to the cylinder of the engine in response to surge and a reformate amount in a reformate storage tank above a reformate threshold. If the reformate amount is above the reformate threshold, then routine 500 continues to 516 ; if not then routine 500 continues to 512 .
At 512 , method 500 includes determining if a rate of reformate production is above a production threshold. The rate and production threshold may be measured in mass per unit time, pressure per unit time or volume per unit time. Further, a rate of production may be inferred from a reformate catalyst temperature, a surface area of the catalyst and an amount of fuel in contact with the catalyst. Inclusion of 512 is one example of how a method may increase the supply of reformate to the cylinder of the engine in response to surge and a rate of reformate production at the catalyst above a production threshold. If reformate production rate is above a production threshold, then routine 500 continues to 516 ; if not, then routine 500 continues to 514 .
At 514 , the routine 500 includes flagging the increase in percentage of reformate entering one or more example engine cylinders as not feasible. In one example of routine 500 , 514 includes setting a variable equal to false (e.g., incrs %=0). In the present example, after 514 , the routine ends, however, in additional examples routine 500 includes adjusting at least one of EGR, VCT, lean burn and spark retard (e.g., as at 420 described above with respect to FIG. 4 ).
In the present example, if reformate amount is above the reformate threshold at 510 and the rate of reformate production is above the production threshold, then routine 500 may continue to 516 . At 516 , routine 500 includes determining if an air to fuel ratio is above an A/F threshold. Inclusion of 516 in routine 500 is one example of determining if the example engine is running in a lean burn mode. Further 516 may include determining if enriching an air and fuel mixture entering an engine cylinder will improve engine combustion and mitigate surge (e.g., if air to fuel is above the A/F threshold) or lead to further surge (e.g., if air to fuel is below the A/F threshold). If the air to fuel ratio is above the A/F threshold, then routine 500 continues to 518 ; if not, then routine 500 continues to 514 , discussed above.
At 518 , routine 500 includes flagging the increase in percentage of reformate entering one or more example engine cylinders as feasible. In one example of routine 500 , 518 includes setting a variable equal to true (e.g., incrs %=1). In the present example, after 518 , the routine ends. In additional examples, routine 500 includes increasing the percentage of reformate entering the example cylinder(s) of the engine (e.g., as at 418 described above with respect to FIG. 4 ).
As discussed above, routine 500 is one example of a subroutine for determining the feasibility of increasing reformate charge concentration. One advantage of routine 500 is that an amount of reformate may be maintained above the example reformate threshold, thereby ensuring an amount of reformate is available to be combusted in the engine later, for example in response to knock. Another advantage of routine 500 is that intake air is not enriched to saturation which may increase hydrocarbon emissions and lowering fuel economy. Further examples of routine 500 include additional processes and determinations and may be arranged differently, (for example, determining if reformate amount is above the reformate threshold (presently at 510 ) after determining if the rate of reformate production is above the production threshold (presently at 512 ).
Turning now to FIG. 6 , a map 600 illustrating engine operating conditions with respect to engine speed-load is shown. In the present example, three engine conditions 610 , 620 , and 630 are shown. The boundary of each condition (e.g., solid line boundary of second engine condition 620 ) includes all of the points on the boundary and within the boundary, including additional engine conditions (e.g., first engine condition 610 ). In additional examples, engine operating conditions may be exclusive to other operating conditions, and not contain the same engine speed-loads as the other operating conditions.
The boundary of first condition 610 is illustrated by a dashed line. First condition 610 includes intermediate engine loads, and low to intermediate engine speeds. First condition 610 may be above a first example s-l threshold and below a second s-l threshold, the second threshold having a greater speed and/or load than the first. Furthermore, in the present example first condition 610 includes engine speeds and loads during which charge dilution via EGR, VVT, boost, etc. may be used. Therefore, an engine operating in first condition 610 which experiences surge may decrease charge dilution and effectively increase charge combustion quality.
An engine operating in the first condition may prioritize engine surge mitigation by first increasing reformate, then decreasing charge dilution and finally adjusting spark timing.
The boundary of second condition 620 is illustrated by a solid line. In one example, second condition 620 includes an entirety of stable engine operating speeds and loads. Second condition 620 may be below the first example s-l threshold and above the second s-l threshold. Second condition 620 may be above a third example s-l threshold and below a fourth s-l threshold, the fourth threshold having a greater speed and/or load than the third. Furthermore, in the present example second condition 620 includes engine speeds and loads during which charge dilution may, or may not, be used. Further still, such speeds and loads may not facilitate the adjustment of charge dilution without decreasing combustion stability or drive feel.
An engine operating in the second condition may prioritize engine surge mitigation by first increasing reformate, then adjusting spark timing.
The boundary of third condition 630 is illustrated by a dash-dot line. In further examples, the boundary of third condition 630 may depart radically from the present example. Third condition 630 may be below the first example s-l threshold and above the second s-l threshold. Furthermore, third condition 630 may be below the third example s-l threshold and above the fourth s-l threshold. In the present example at least one of a reformate amount is above an example reformate threshold and a rate of reformate production is above an example production threshold. Adjusting reformate amount provided to an example engine in the third condition allows for mitigation, prevention, or limiting of engine surge across a wide range of engine loads and speeds. Further, adjusting reformate amount may enable a continued use of aggressive charge dilution and spark timing, thereby increasing engine performance and efficiency.
Note that the example control and estimation routines included herein can be used with various engine and/or vehicle system configurations. The specific routines described herein may represent one or more of any number of processing strategies such as event-driven, interrupt-driven, multi-tasking, multi-threading, and the like. As such, various acts, operations, or functions illustrated may be performed in the sequence illustrated, in parallel, or in some cases omitted. Likewise, the order of processing is not necessarily required to achieve the features and advantages of the example embodiments described herein, but is provided for ease of illustration and description. One or more of the illustrated acts or functions may be repeatedly performed depending on the particular strategy being used. Further, the described acts may graphically represent code to be programmed into the computer readable storage medium in the engine control system.
It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. For example, the above technology can be applied to V-6, I-4, I-6, V-12, opposed 4, and other engine types. The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various systems and configurations, and other features, functions, and/or properties disclosed herein.
The following claims particularly point out certain combinations and subcombinations regarded as novel and nonobvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.
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Engine surge includes oscillations in engine torque resulting in bucking or jerking motion of a vehicle that may degrade driver experience. The present application relates to increasing reformate entering an example engine cylinder in response to engine surge.
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BACKGROUND OF THE INVENTION
The present invention relates to a film rewinding device for a camera in which camera control operations such as the photometric operation, exposure control operation, film winding operation and film rewinding operation are carried out by the execution of a microprocessor program.
A camera using a microprocessor is well known in the art in which camera control operations such as the photometric operation and exposure control operation are performed by the execution of a microprocessor program. Such a camera has a motor-driven film conveying mechanism which is controlled by the microprocessor. The film is automatically wound with this mechanism.
To rewind the film, the film rewind button is held depressed. The depression of the rewind button closes a rewind switch through which electric power is supplied to the film conveying mechanism. The film rewind button must be maintained depressed until the film has been completely rewound.
Holding down of the film rewind button until completion of the film rewinding operation is inconvenient to the operator of the camera. Therefore, it is desirable that the camera be designed so that the film rewinding operation can be accomplished by only momentary depression of the rewind button. This requirement may be achieved by the provision of a mechanism with which the rewind switch is held continuously closed after only momentary depression of the rewind button. However, this arrangement results in the requirement for another operation; that is, releasing the rewind switch upon completion of the film winding operation. Furthermore, if the operator forgets to open the rewind switch, electric power will be wasted because power will be supplied to the camera control section, including the motor mechanism and the microprocessor, until the rewind switch is opened.
In view of the foregoing, an object of the present invention is to provide a film rewinding device which accomplishes film rewinding with the rewinding switch operated only momentarily.
SUMMARY OF THE INVENTION
The foregoing and other objects of the invention have been achieved by the provision of a film rewinding device for a camera which is controlled by the execution of microprocessor program in which, according to the invention, an electric power supply circuit for a film rewinding operation comprises: switching means for electrically connecting a camera control section to an electric power source; first signal generating means including a rewind switch which is placed in a second state from a first state to output a first signal when operated and which is then mechanically held in the second state; second signal generating means for producing a second signal when the second signal generating means is in its normal state; gate means which is opened upon reception of the first and second signals to provide an output which renders the switching means conductive to allow the supply of electric power for film winding operations; detection response means including a detecting switch for detecting the completion of a film winding operation to provide a detection signal, the detection response means changing the state of the second signal generating means in response to the detection signal to prevent the production of the second signal to render the switching means nonconductive; and means for changing the state of the rewind switch to the first state from the second state, and thereafter restoring the state of the second signal generating means to the normal state.
In the film rewinding device of the invention, the second signal generating means produces the second signal in the normal state, the state from which the film can be rewound, in advance. Under this condition, the state of the rewind switch is changed from the first state to the second state to produce the first signal. Upon reception of the first and second signals, the gate means provides an output which renders the switching means between the camera control section and the electric power source conductive, thereby permitting the supply of electric power for a film rewinding operation.
When the detecting switch detects the completion of the film rewinding operation, the detection response means operates to prevent the production of the second signal, and therefore the switching means is rendered non-conductive with the gate means closed.
The detection response means inhibits the production of the second signal in the presence of the first signal, that is, when the rewind switch is in the second state. When the rewind switch is placed in the first state again to eliminate the first signal, the inhibition of the production of the second signal is eliminated; that is, the second signal is produced again.
With the film rewind device thus constructed, the film will be rewound to the end merely by momentarily operating the film rewind switch, and the supply of electric power is interrupted substantially at the same time the rewinding operation is accomplished.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of a power supply circuit in a film winding device constructed in accordance with a preferred embodiment of the present invention;
FIG. 2 is a flowchart used for a description of the operation of a microprocessor in a camera control section of the film winding device of the invention; and
FIG. 3 is a plan view showing a rewind switch and an operating mechanism associated with the rear cover of a camera.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the invention will be described with reference to the accompanying drawings.
FIG. 1 is a circuit diagram showing a power supply circuit forming a film rewinding device. In FIG. 1, reference numeral 1 designates an electric power source, namely, a battery, and reference numerals 2 and 3, transistors forming a switching circuit connected between the power source 1 and a camera control section 4. The camera control section 4 includes various elements and circuits, such as a photometric circuit and an exposure control circuit, necessary for camera control.
The camera control section 4 further includes a conventional E 2 PROM, namely an I/O memory 6 for storing film rewind completion data. The I/O memory 6 supplies a set signal to an flip-flop 9 when instructed by the program of the microprocessor 5, thereby rendering the switching circuit nonconductive in specific cases, for instance, when the battery 1 is replaced immediately after the film has been rewound. The I/O memory 6 will be described below in more detail.
Further in FIG. 1, SW 1 designates a rewind switch, which forms a first signal generator together with a resistor 7 connected in series therewith and an inverter 8 whose input terminal is connected to the connecting point of the switch SW 1 and the resistor 7. The series circuit of the rewind switch SW 1 and the resistor 7, as shown in FIG. 1, is connected to the power source 1. When the switch SW 1 is closed, a signal at the logic level "1" is outputted, as a first signal S 1 , by the inverter 8. The first signal S 1 is applied to a gate circuit (described below) and supplied, as an instruction signal, to the microprocessor 5 to start the film rewinding operation. The rewind switch SW 1 is designed so that the armature can be manually moved from the open position to the closed position with the operator's finger and then is mechanically held at the closed position. It is returned to the open position when the rear cover of the camera is opened.
Further in FIG. 1, the flip-flop 9 forms a second signal generator together with an inverter 10. The flip-flop 9 is reset by a normally closed reset switch SW 2 , the armature of which is moved to the open position when the rear cover of the camera is opened. The reset switch SW 2 is connected through a resistor 11 to the power source 1. When the rear cover is opened, the reset switch SW 2 is opened, as a result of which a high logic level voltage "H" is applied at the connecting point b of the switch SW 2 and the resistor 11. This "H" voltage is applied as a first reset signal S 3 to the flip-flop 9 through an OR gate 12.
Accordingly, when the rear cover of the camera is closed after the film has been loaded, that is, when the camera is in the "normal" state and the film can be rewound, the output terminal Q of the flip-flop 9 is set to the "0" logic level. The "0" output level at the output terminal Q is held until the film rewinding operation has been completed, regardless of the amount of film wound or unwound. Accordingly, during this time the inverter provides a "1" output as the second signals S 2 .
A second reset signal is applied through the OR gate 12 to the flip-flop 9 to reset the latter. The second reset signal S 4 is generated by applying to a buffer 15 an integration voltage developed at the connection point of a capacitor 14 and a resistor 13 connected at its other terminal to the power source 1. The buffer 15 may be implemented with a conventional device such as waveform-shaping Schmitt trigger circuit. A diode 16 shunting the resistor 13 provides a path for discharging the capacitor 14.
When a battery is first placed in the camera or the battery is replaced, the second reset signal S 4 is produced to reset the flip-flop 9 so that the output terminal Q is held at "0".
On the other hand, when the flip-flop 9 is set by a "1" signal outputted by the microprocessor 5, raising the output terminal Q to the "1" level, generation of the second signal S 2 is stopped. The flip-flop is then set by supplying a clock pulse to its clock terminal C with a "1" signal applied to its set terminal I.
Further in FIG. 1, reference numeral 17 designates an AND gate. The AND gate 17 receives the first and second signals S 1 and S 2 and produces in response a gate output signal S 5 , which is applied to the base of the biasing transistor 3 in the switching circuit described above. When the signal S 5 is in the "1" (or "H") state, the transit 3 is turned on.
Still further in FIG. 1, SW 3 designates a detecting switch which is opened and closed with a predetermined period as the film is being rewound. At the end of the film rewinding operation, the periodic on/off operation of the switch SW 3 is stopped with its armature held at either the open or closed position. Thus, the completion of the film winding operation can be detected by detecting the suspension of the periodic on/off operation of the switch SW 3 . The detecting switch SW 3 , together with a resistor 18 and the microprocessor 5, forms a detection response circuit.
As shown in FIG. 1, the detecting switch SW 3 is connected through the resistor 18 to the power source 1. The detecting switch is repeatedly opened and closed during the film rewinding operation. Accordingly, a voltage pulse is produced at the connecting point d of the switch SW 3 and the resistor 18 at a predetermined period during the film rewinding operation. At the end of the film rewinding operation, the repetitive on/off operation of the detecting switch SW 3 is stopped, whereupon the voltage at the connecting point d is maintained at a constant "H" or "L" level. The voltage developed at the connecting point d, as described above, is supplied as a detecting signal S 6 to the microprocessor 5. When the period of the detection signal S 6 exceeds a predetermined value, the microprocessor 5 supplies a "1" signal as a set signal to the flip-flop 9. That is, the program for the microprocessor determines when the period T S of the voltage pulse provided at the connecting point d during the film rewinding operation exceeds a predetermined value T 0 , whereupon the flip-flop 9 is set.
The detecting switch SW 3 is operated for example, by rotation of a sprocket which is rotated as the film is rewound. Otherwise, an optical switch which senses the passing of the film's perforations can be used.
The operation of the film rewinding device constructed as described above will be described with reference to the case where the film has already been wound.
When the rewind switch SW 1 is open, no "1" signal will be present at the connecting point a, and hence the first signal S 1 will be in the "0" state. Accordingly, the output of the AND gate 17 is a "0" and the transistors 2 and 3 are off. That is, the camera control section 4 is electrically disconnected from the power source 1. The second signal S 2 is, however, in the "1" state because the output terminal Q of the flip-flop 9 is held at "0", as described above.
When the rewind switch SW 1 is closed, its armature is held at the "closed" position. As a result, the signal at the connecting point a is set to "0" and the first signals S 1 at the output of the inverter 8 is set to "1". Accordingly, with two "1"s on its two inputs, the AND gate 17 outputs a "1" and the transistor 3 is rendered conductive, thus also turning on the transistor 2. As a result, the camera control section 4 is electrically connected to the power source 1, and the rewinding instruction is applied to the microcomputer 5. Upon energization of the camera control section, a film conveying motor mechanism starts rewinding the film as instructed by the microprocessor 5.
When the film rewinding operation is started in this manner, the voltage pulse train detection signal S 6 is supplied to the microprocessor 5. When it is detected that the film rewinding operation has been completed by sensing the period of the detection signal S 6 in the manner described above, a "1" signal is applied to the set terminal I of the flip-flop 9 to set the latter. At the same time, the film rewinding operation completion data is written into the I/O memory 6. When the flip-flop 9 is set, its output terminal Q is raised to the "1" level, and hence the second signal S 2 is returned to "0". Therefore, the AND gate 17 outputs a "0", turning off the transistors 2 and 3 in that order.
When the film rewinding operation has been completed, the camera control section is disconnected from the power source 1. As long as the rear cover is closed, the reset switch SW 2 will remain closed, and therefore the second signal remains in the "0" state, holding off the supply of power from the source 1. When the rear cover is subsequently opened, the rewind switch SW 1 is opened, setting the switch SW 1 to the "0" state. The switch SW 2 is also opened. When the switch SW 2 is opened, the signal at the output terminal Q is set to "0", whereupon the inverter produces a "1" level for the second signal S 2 again.
Although the second signal is a "1", the AND gate 17 remain closed since the first signal S 1 is in the "0" state. Therefore, the transistors 2 and 3 remain off. Even when the rear cover is closed, the rewind switch SW 1 will be held open, maintaining the switching circuit in the open condition.
If the battery is replaced after the completion of a film winding operation but before the rear cover is opened to remove the film, the switching circuit will remain in the open state. When the battery is replaced, the second reset signal S 4 , which is generated in response to the integration voltage at the connection point c of the resistor 13 and the capacitor 14, will to to a "1", resetting the flip-flop 9. As a result, the second signal S 2 is set to a "1" and the AND gate 17 is then opened, rendering conductive the switching circuit. At this time, the microprocessor 5 reads the film rewinding instruction data from the I/O memory 6 and supplies a "1" signal to the flip-flop 9 to again set the latter. As a result, the second signal S 2 is returned to the "0" state, turning off the transistor 3 and consequently the transistor 2.
The winding operation data stored in the I/O memory 6 is erased according to the operation program for the microprocessor 5.
FIG. 2 is a flowchart showing the operation of the microprocessor with the first signal S 1 and the detection signal S 6 in the "1" state.
In the preferred embodiment described above the rewind switch SW 1 is opened in association with the opening of the rear cover of the camera. However, the rewind switch SW 1 may be restored manually if desired.
Referring now to FIG. 3, the mechanical arrangement of the switches SW 1 and SW 2 will now be described. FIG. 3 illustrates the rear cover 21 and a rear cover opening member 22 provided in the camera body. The rear cover opening member 22 is slidably moved in a horizontal direction in FIG. 3 by manual operation of a member 22a.
When the rear cover 21 is closed, the rear cover opening member 22 is positioned so that an end portion of the member 22 contacts the operating arm of the switch SW 2 . In this case, an engaging member 21b of the rear cover 21 engages a receiving member 23b of the rear cover opening member 22, and the rear cover opening member 22 is biased toward the switch SW 2 by a biasing spring 24, whereby the switch SW 2 is maintained closed.
When the member 22a is manually moved rightward in FIG. 3 to open the rear cover 21, the engagement of the member 21b and the receiving member 22b is released, allowing a stop 23 to rotate in the counterclockwise direction under the force of the spring 24. The end portion of the stop 23 comes into abutment with the rear cover opening member 22, as depicted in FIG. 3, and the member 22 is held at that position.
When the rear cover 21 is closed the portion 21a pushes the stop 23 downwardly, releasing the abutment of the stop 23 and the rear cover opening member 22, whereupon the engaging member 21b is received by the member 22b to keep the cover 21 closed.
The switch SW 2 is an ordinary switch capable of carrying out its switching operation in response to the opening of the rear cover.
The switch SW 1 is also an ordinary switch which is provided in the camera body. When a rewind switch operating member 25 is manually moved downwardly in FIG. 3 to turn-on the rewind switch SW 1 , the engagement of the member 25 and a latch 27 is released, allowing the latch 27 to rotate in a counterclockwise direction under the force of a spring 28. Then the latch 27 is positioned as indicated by a dotted line in FIG. 3 to maintain the switch SW 1 closed. When the member 22 is slidablely moved as indicated by an arrow in FIG. 3 to open the rear cover 21, the right end portion of the member 22 pushes the latch 27 so that the latch 27 rotates in a clockwise direction and the latch 27 is returned under the force of a spring 26 to the position indicated by a solid line in FIG. 3.
An example of the switch SW 3 is disclosed in Japanese Laid-Open Patent applications Nos. 83827/1983 and 141630/1982. (The switch SW 3 corresponds to a switch SW 6 of Application No. 83827/1983 and to a switch SW 2 of Application No. 141630/1982.)
The invention has been described with specific reference to a film rewinding power supply circuit. Of course, in practice there is also provided a photometric circuit, an exposure control circuit, etc., and power supply circuits are also provided therefor.
As described above, in the film rewinding device of the invention, once the rewind switch is operated to set it to the second (closed) state, even when the rewind switch is released, the camera control section will be maintained connected to the power source to allow the rewinding of the film to be completed. Thus, the film rewinding device of the invention provides a simpler operation than the prior art device in which the film rewind switch must be continuously depressed until the rewinding operation has been completed.
Furthermore, in the film rewinding device of the invention, the supply of power to the camera control section is automatically stopped when the film rewinding operation has been completed. Therefore, even if the camera is put away without restoring the rewind switch to the first state, the drain on the power source is negligibly small. This makes it possible to design the camera so that the rewind switch is restored in association with the opening to the rear cover.
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A film rewinding device for a camera in which the rewind switch need only be momentarily depressed to initiate the rewinding operation. The rewind switch is a type which remains depressed after momentary activation. Activation of the rewind switch produces a first signal which is ANDed with a second signal which is present when the camera is in a normal state and it is possible to perform a rewinding operation. When both the first and second signals are active, a switching circuit applies power to a control section to effect the rewinding operation. The completion of the rewinding operation is detected by sensing the movement of the film. When the rewinding operation has been completed, the second signal is deactivated, thereby removing power from the control circuitry. The rewind switch is opened when the rear cover is opened.
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This invention relates to silicide straps across polysilicon layers in integrated circuits, and more particularly to straps formed by self-aligned silicidation.
BACKGROUND OF THE INVENTION
Integrated circuits often make use of multiple interconnecting layers. Such arrangements reduce chip area for a given number of devices or circuit elements. In order to provide electrical contact between two layers, for example, contact vias may be etched through an interlayer dielectric during fabrication. Alternatively, straps may be formed connecting one layer to another layer. One form of these straps makes use of a "butting contact" 10 such as that illustrated in FIG. 1. Straps are also used for interconnection of other elements or layers, wherever oxide or other non-conducting gaps need to be bridged.
The vias or straps must be fabricated of conductive material in order to provide electrical communication between the layers. Although other conducting materials may be used, it is advantageous to employ a silicide such as titanium silicide (TiSi 2 ) due to the low resistance or ohmic contact it forms with silicon, including both single crystal silicon and polycrystalline silicon. The latter material is often referred to as polysilicon, or poly.
Silicides have also been used for local interconnection, to provide low resistance electrical contact between device active regions within a silicon substrate (e.g., the drain of a MOSFET transistor) and other devices or conducting layers. Aluminum and other metals have lower sheet resistance than silicide. However, integration of these metals as a strap or local interconnect is difficult because of their high temperature instability and poor step coverage into contacts during deposition. The surface upon which the metal is to be deposited must be relatively smooth and therefore requires some type of planarization prior to metal deposition, which complicates the process. Additionally, many of the typical low-resistance metals also can contaminate the substrate in which the active devices are formed, causing parasitic leakage currents or device failure. For this reason, a diffusion barrier must also be formed to prevent diffusion of the metal ions to the silicon substrate. This also adds a level of complexity not required for alternative local interconnect materials. Thus, especially for narrow contacts formed in VLSI and ULSI circuits, silicide is increasingly used as a low resistance contact between device active areas and aluminum lines, or simply as the sole layer in a local interconnect.
For many interconnect applications, it is possible to employ a self-aligned silicidation process ("salicidation"). Salicidation is produced by depositing an elemental refractory metal layer, such as titanium, over silicon in any form, such as silicon substrates, amorphous silicon or polysilicon layers. Reaction between the titanium and the silicon takes place during a high temperature anneal or sinter step. The process is referred to as "self-aligned" because silicide forms only where the metal layer contacts silicon, for example, through contact openings. Ordinarily, salicidation is advantageous because silicide is formed exactly where it is desired, that is, over the polysilicon and substrate regions defined by a prior contact mask.
Salicidation, however, is sometimes difficult to perform. FIG. 1, for example, illustrates a butting contact opening 10 in an insulating layer 12, which covers a substrate 14, a first polysilicon layer 16, and a second polysilicon layer 18. The butting contact is well known and can be formed by a conventional photolithographic process and subsequent etch. Salicidation cannot ordinarily be employed to form a silicide strap across the polysilicon layers 16 and 18. It is often difficult to bridge an interlayer oxide layer 20 and a sidewall spacer 22. The spacer 22 forms as a byproduct of the contact etch.
FIG. 2 shows a strap 30 which would result if conventional salicidation techniques were applied to the butting contact 10 across two relatively thick polysilicon layers 16 and 18. After etching the contact opening 10 (FIG. 1) and depositing a layer of elemental titanium, a first sinter step results in the silicide strap 30 forming across the contact opening 10 (FIG. 2). A layer of unreacted titanium metal 32 and a layer of titanium nitride (TiN) byproduct 34 would next be selectively removed by processes known to this art. A final sinter may be performed to lower the silicide's sheet resistance to acceptable levels by converting the titanium from the C49 phase to the lower resistance C54 phase.
In the first place, either the thickness of deposited titanium needs to be carefully controlled, or the sinter time needs to be strictly controlled to avoid over-consumption consumption of the underlying silicon. Overconsumption would result in poor contact between the polysilicon layers and the strap. Even if overconsumption is avoided, the resulting strap 30 would be fragile. Though illustrated as spanning the gap formed by the interlayer oxide 20 and the oxide spacer 22, the strap 30 becomes very thin at a bridge 36 over the oxide spacer 22. This narrow bridge 36 would naturally demonstrate very high resistivity or would in practice be subject to mechanical failure (breakage).
The bridge 36 is too thin due to a lack of silicon to feed the salicidation process. Since salicidation consumes the underlying silicon in order to form TiSi 2 , spanning thin polysilicon layers with this method would pose even more difficulty. An intrinsic resistor or a thin film transistor, for example, might be formed from a very thin silicon layer 54 (see FIG. 3). The thin polysilicon layer 54 cannot supply the correct proportion of silicon to titanium for salicidation over the thin layer 54. The strap produced by a standard salicidation process would be metal-rich and thus indistinguishable from other metal byproducts for purposes of the selective etch following the first sinter.
Because of these problems, manufacturers desiring straps across thin or thick polysilicon layers have necessarily resorted to alternatives other than salicidation. Traditionally, conductive straps have been fabricated through deposition techniques. Polysilicon or metal, for example, can be deposited into a contact opening directly onto the polysilicon layers and the substrate by co-sputtering, co-evaporation or chemical vapor deposition (CVD) techniques. Depositing silicide is costly, however, due to the requirement of an extra mask. A mask is necessary either for depositing the silicide at appropriate points on the circuit, or for etching away unwanted silicide. In either case, space is wasted in providing leeway for misalignment of the mask.
Salicide cladding over the substrate to form local interconnect can also be problematic. FIG. 2 illustrates simultaneous formation of a cladding 44 along with the salicided strap 30, discussed above. Salicidation over a thin active region 46, in order to provide ohmic contact to both the underlying active area 46 and to metal lines or to other circuit nodes (not shown), also consumes silicon of the substrate 14. During anneal, silicon from the substrate 14 dissolves into the overlying metal layer. Dissolution is not uniform, though, and as a result metallic spikes 48 are formed in the thin active region 46, interfering with the device's p-n junction. To remedy this situation, a polysilicon or amorphous silicon layer may be provided between the device active region and the refractory metal layer. However, an additional mask step is required to ensure correct alignment of the deposited silicon layer, increasing fabrication expense.
It is thus an object of the present invention to provide a self-aligned silicide strap for connection of thin polysilicon layers in an integrated circuit.
It is a further object of the present invention to provide such a strap without requiring post-salicidation masks for patterning the silicide.
It is a still further object of the present invention to reduce junction spiking during metallization of device active regions.
SUMMARY OF THE INVENTION
The present invention provides a method of forming self-aligned silicide straps across silicon layers. The method comprises opening a contact window in a top insulating layer, which step exposes the silicon layers to be strapped. A thin silicon layer and a metal layer are deposited over the structure. The structure is then sintered to form a silicon-rich silicide over the exposed silicon layers.
The contact window forming step may also simultaneously expose one or more circuit nodes, such as device active areas, to be clad for local interconnection. In this case, the silicon-rich silicide also forms over these circuit nodes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial schematic sectional view of an integrated circuit, illustrating a butting contact opening over relatively thick polysilicon layers, as provided for in the prior art.
FIG. 2 illustrates a stage in forming silicide straps in the integrated circuit of FIG. 1, making use of prior art salicidation techniques.
FIGS. 3-6 are partial schematic sectional views of an integrated circuit having a thin polysilicon layer, illustrating generally the method of the present invention.
FIG. 3 illustrates an integrated circuit following deposition of an insulating layer and formation of contact windows or openings in the insulating layer.
FIG. 4 illustrates the integrated circuit of FIG. 3 following deposition of a thin polysilicon layer and an elemental refractory metal layer.
FIG. 5 illustrates the integrated circuit of FIG. 4 following a silicidation step.
FIG. 6 illustrates the integrated circuit of FIG. 5 following a cleaning step.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a method of forming self-aligned silicide straps spanning polysilicon layers which are too thin to supply adequate amounts of silicon for the salicidation process. Such thin polysilicon layers are often found in VLSI circuits, in the form of thin film transistors (TFTs) and resistors. In order to support salicidation, additional polysilicon is provided to the structure. The additional polysilicon allows the use of thicker titanium layers without fear of overconsuming the underlying silicon, while at the same time retaining self-alignment of the salicide process.
FIG. 3 illustrates a stage in integrated circuit processing which represents a starting point for an embodiment of the present invention. Overlying a substrate 50, a first polysilicon layer 52 ("poly-1") and a second polysilicon layer 54 ("poly-2") are both at least partially exposed. In the preferred embodiment, the substrate 50 is also exposed through a drain contact 58. The poly-1 52 and poly-2 54 layers in the illustrated embodiment are exposed in step formation, resulting in a butting contact opening 56 or simply butting contact 56. In different embodiments, other layers or circuit nodes may also be present and exposed. Processes used to fabricate the circuit to this point vary and at any rate are known in this art.
The butting contact 56 and the drain contact 58 were etched through a top insulating layer 60 using standard photolithographic processes and etch steps. The insulating material in the preferred embodiment is an oxide 60 in the form of tetraethyl orthosilicate (TEOS), but it may also be a nitride or other passivating material which is relatively non-reactive and impervious to later process steps, such as many dielectrics. If other layers (not shown in this embodiment) are to be strapped, they too would be exposed by the etch step.
The invention is of particular utility where a gap must be spanned between silicon layers in an integrated circuit, and especially where at least one polysilicon layer is too thin to support salicidation. The gap is generally an electrically isolating layer of some sort. In the preferred embodiment, a gap 62 to be spanned is represented by an interlayer oxide 64 and an oxide spacer 66. The oxide spacer 66 naturally results as a byproduct of a previous etch step which opens the butting contact 56.
The thickness of the polysilicon layers may be between 100 Å and 10,000 Å, depending upon the application. Although they need not be thick enough to fully supply silicon to the later silicidation process, they must be thick enough to supplement the process. In the preferred embodiment, the poly-1 layer 52 should be between about 1200 Å and 4000 Å, and most preferably at least about 2500 Å. The poly-2 layer 54 may also be within the same range. However, due to particular utility of practicing the invention in association with thin polysilicon layers, the poly-2 layer 54 of the preferred embodiment is most preferably about 250 Å thick. Thus, the poly-2 layer 54 of the preferred embodiment is too thin to completely support silicidation of a typical metal layer used for self-aligned straps, such as a 500 Å layer of titanium.
The interlayer oxide 64 represents the bulk of gap 62 to be spanned. Thus, holding all other parameters constant, there will be a maximum thickness beyond which the gap 62 cannot be spanned. For the preferred embodiment, the interlayer oxide 64 thickness should be between about 100 Å and 1000 Å, and most preferably about 200 Å.
The contact mask may or may not provide for an opening over the silicon substrate 50. In the preferred embodiment, a device active region 68 is to be clad with silicide so that the drain contact 58 is provided. Thus, the invention advantageously allows formation of silicide cladding while at the same time providing silicide straps across polysilicon layers, without the need for additional masks.
FIG. 4 illustrates the integrated circuit following the next two deposition steps. A silicon source layer 70, preferably in the form of a third polysilicon layer 70 (poly-3), is deposited over the top oxide 60 to contact the poly-2 54 and poly-1 52 layers and the active area 68. A metal layer 72, preferably comprising a refractory metal, is next deposited over the poly-3 layer 70. In the preferred embodiment, elemental titanium (Ti) is deposited. Since the silicidation step to follow is self-aligned, no mask is required for either of these two deposited layers. The poly-3 layer 70 essentially serves as a source of silicon (Si) for the later silicidation step. Accordingly, grown polysilicon, deposited amorphous silicon (α-Si), or any other suitable silicon source may be used in place of the deposited poly-3 layer. In addition, the order of deposition may be reversed in alternative embodiments such that the silicon source layer overlies the metal layer.
Although any known method of depositing the poly-3 70 and titanium metal 72 layers may be used, it is important that the layer thicknesses be carefully controlled. Thus, CVD methods, and especially low pressure methods (LPCVD), are preferred for a conformal polysilicon deposition with good step coverage. For the preferred embodiment, the poly-3 layer 70 is deposited with silane (SiH 4 ) as the silicon source, at a temperature of about 620° C. and a pressure of about 200 mTorr. The titanium layer is preferably deposited by sputtering a titanium target, as will be understood by one skilled in the art.
The thickness of the poly-3 layer 70 is chosen such that it cannot support salicidation by itself. The maximum thickness of the poly-3 70 thus depends upon the thicknesses of the titanium layer 72 and the poly-2 layer 54. The titanium layer 72 is preferably between about 200 Å and 1500 Å, and most preferably about 500 Å. For the preferred embodiment, with a titanium deposition of about 500 Å, the poly-3 layer 70 should preferably be between about 100 Å to about 300 Å and more preferably less than 200 Å.
Note, however, that the maximum thickness of the poly-3 layer 70 will be larger if a thicker metal layer 72, and thus thicker silicide, is desired. In the case of titanium metal, the ratio of silicon to titanium (Si:Ti) should be low enough to produce a metal-rich silicide, such as Ti 5 Si 3 or even Ti 3 Si, when annealed over unpatterned regions of the top oxide layer 60. For the preferred embodiment, the thickness ratio of Si:Ti (poly-3 layer 70 thickness to titanium layer 72 thickness) should be between about 1:1 and 1:5, more preferably between about 1:2 and 1:4, and most preferably about 1:3. In any case, the thickness of the poly-3 layer 70 over the oxide 60 should be such that it supplies insufficient silicon for complete silicidation of the refractory metal layer 72. "Complete silicidation" will be defined below.
Silicidation is next performed, preferably in an anaerobic environment such as nitrogen gas to prevent contamination of the silicide with oxides. However, for alternate embodiments in which the silicon source layer is laid over the metal layer, greater amounts of atmospheric contaminants are tolerable, as disclosed in Lou et al, "The Process Window of a-Si/Ti Bilayer Metallization for an Oxidation-Resistant and Self-Aligned TiSi 2 Process," IEEE Transactions on Electron Devices, Vol. 39, pp. 1835-43 (Aug. 1992). For the preferred embodiment, where titanium overlies silicon, silicidation may be accomplished by sintering or annealing the metal and silicon structure at a temperature between about 600° C. and 900° C., more preferably between about 600° C. and 700° C., most preferably about 650° C. This first anneal may be performed for between 10 seconds and 60 seconds, but most preferably for about 30 seconds.
FIG. 5 illustrates the result of the silicidation step. Although, individually, both the poly-2 54 and the poly-3 70 are too thin to support silicidation of all the titanium 72, the combination of the poly-2 54 and poly-3 70 at the butting contact opening 56 over the poly-2 layer 54 does provide enough silicon to support silicidation of the titanium layer 72. Similarly, the combination of the poly-1 52 and poly-3 70 at the butting contact opening 56 over the poly-1 layer 52 also provides enough silicon for complete silicidation. As a result, a stable silicide represented by "TiSi x " is formed in regions within the contact opening 56, where x approaches 2. Thus, a silicide strap 80 is formed, spanning the poly-1 52 and poly-2 54 layers.
In contrast, in regions over the oxide layer 60, the poly-3 70 alone is available for silicidation with the titanium layer 72 (FIG. 4). In these regions, a metal-rich silicide 82 is formed, which may be represented by "TiSi y " 82, where y is less than x. This terminology is simply meant to convey atomic or molar proportions, rather than a stoichiometric compound. The TiSi y 82 may include a mixture of Ti 5 Si 3 and Ti 3 Si.
Due to the lower ratio of silicon to titanium, it is possible to selectively remove the more metallic TiSi y 82 without attacking much of the silicon-rich TiSi x which forms the silicide strap 80. The selective removal may be accomplished by a conventional wet metal etch or cleaning step. For example, a 1:10 solution of hydrogen peroxide (H 2 O 2 ) and sulfuric acid (H 2 SO 4 ), known as HH, may be used in this step. The silicon-rich and stable TiSi x silicide strap 80, predominantly TiSi 2 , remains relatively unharmed by the etch.
Since, in the preferred embodiment, the silicidation step is performed in a nitrogen environment, a thin layer of titanium nitride 86 (TiN) is also formed as a byproduct of the reaction. The TiN layer 86 overlies all areas, including both TiSi x of the strap 80 and the metal-rich TiSi y 82. This TiN layer 86 may also be removed, along with the TiSi y 82, in the metal etch step described above.
A second anneal may be performed after the wet etch, in order to lower the resistance of the silicide strap 80. This anneal, which may be performed at about 800° C. for about 20 seconds, converts titanium silicide from the C49 phase to the C54 phase. It will be understood, however, that alternative silicide materials may not require this second anneal step.
The definition of "complete silicidation" is therefore silicidation until the ratio of Si:Ti within the silicide is such that the silicide would be left largely undamaged by cleaning step described above. For the preferred etch chemical concentrations, the silicide strap 80 formed in the butting contact opening 56 comprises TiSi x , where x is preferably greater than about 2.0, and most preferably x is equal to about 2.0. Conversely, the metal-rich silicide 82 formed over the top oxide layer 60 comprises TiSi y , where y is less than about 2.0 and most preferably less than about 1.0.
It will be understood by one of skill in the art that the range of layer thickness ratios approximately corresponds to the resultant values of x and y in TiSi x and TiSi y , respectively. For different refractory metals, the preferred atomic ratios, or values of x and y, may remain as described for titanium silicide. Thus, if tungsten silicide is to form the silicide strap, WSi x should form within the butting contact, where x approaches 2, and similarly for CoSi 2 . The thickness of the deposited tungsten metal layer will differ from that of a corresponding titanium layer, however, since tungsten and titanium have different densities.
Note that, although thickness of the deposited poly-3 layer 70 and the titanium layer 72 are important to optimal performance, the silicide strap 80 of the present invention is less sensitive to metal layer thickness than prior art salicide straps have been. Thus, for a given thickness of poly-2 or poly-1 layers, the present invention allows use of a thicker titanium layer without fear of overconsuming the polysilicon layers below. This situation is said to result in a greater process window for salicidation.
Additionally, the strap process may be combined with the fabrication of a cladding over the active area 68 or of a local interconnect. In the preferred embodiment, some silicon from the substrate 50 aids silicidation through the drain contact opening 58, but less spiking occurs due to the additional silicon provided by the poly-3 70 (see FIG. 4). Thus, the combination of the substrate 50 and poly-3 70 supplies enough silicon to support silicidation over the active area 68. A resultant cladding 90 comprises TiSi x , similar to the silicide strap 80 discussed above. Thus, the silicide cladding 90 also remains undamaged by the wet etch described above. As is known in the art, the silicide cladding 90 forms ohmic contact with the active area 68 and thus requires no mask for doping.
The present invention may also be combined with the formation of an extensive local interconnect. To accomplish this, an additional layer of polysilicon would be deposited though a local interconnect mask over the insulating layer before titanium deposition. In this way, additional silicon is provided for complete silicidation of entire lines from one active area to another, thereby eliminating the second level of metallization. This method is especially economical over short distances, where sheet resistance remains unimportant relative to contact resistance.
FIG. 6 illustrates the integrated circuit following the selective metal etch or cleaning step. The silicide strap 80, largely comprising TiSi 2 , provides conduction between the poly-1 52 and the poly-2 54, while the excess metal, including TiN 86 and metal-rich TiSi y 82 (FIG. 5), has been cleaned away. The preferred embodiment includes a silicide cladding 90, formed over the active region 68 within the substrate 50. The cladding 90 provides low-resistance contact to later-formed conducting layers such as aluminum or to other circuit nodes. Because the silicidation is self-aligned, no additional mask is required.
Although the foregoing invention has been described in terms of certain preferred embodiments, other embodiments will become apparent to those of ordinary skill in the art, in view of the disclosure herein. Accordingly, the present invention is not intended to be limited by the recitation of preferred embodiments, but is instead intended to be defined solely by reference to the appended claims.
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A method is disclosed for providing a self-aligned silicide strap for connecting thin polysilicon layers (poly-1 and poly-2, etc.) separated by non-conducting gaps. A butting contact opening to the layers is formed in an overlying insulating layer. The contact exposes the poly-1 and poly-2 layers. A thin polysilicon layer (poly-3) is then deposited over the insulating layer and into the contact. This is followed by deposition of a refractory metal layer. The poly-3 layer should be thin enough that, alone, it cannot supply enough silicon to support full silicidation of the refractory metal layer. The structure is next sintered so that a silicide strap is formed in the contact opening and across exposed portions of the poly-1 and poly-2 layers. The ratio of silicon to titanium in regions over the insulating layer is lower than that in the strap, such that these more metallic regions may be selectively removed. The preferred embodiment simultaneously provides cladding of device active areas, the silicon added by poly-3 serving to reduce spiking into the active areas.
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FIELD OF THE INVENTION
[0001] This invention relates to a method and apparatus for the treatment of domestic waste, for the purpose of disposing of it in an ecologically sound manner and producing from it combustible gases, particularly carbon monoxide and hydrogen.
BACKGROUND OF THE INVENTION
[0002] The ecological disposal of domestic waste and the production of useful products, specifically combustion gases from it, form the subject matter of a number of proposals in the prior art.
[0003] Domestic waste is usually treated after having been accumulated as municipal waste. Its composition is highly variable. It is often referred to as “biomass”, since it contains a considerable proportion of food residues, but in reality it is only partially a biomass. It may, and frequently does, also contain considerable amounts of cardboard and paper and generally cellulosic material or partly cellulosic material such as wood. It also does contain inorganic materials, such as metal or glass or even rocks or sand, and other materials such as plastics, fabrics, and so on. As a result, part of the waste can produce combustible gases and an oxidation residue and part remains substantially unchanged, so that, at the end of any disposal and utilization process, a substantially inorganic ash is produced. All possible compositions of domestic waste can be treated by the method and apparatus of this invention, which is therefore not limited to any range of compositions and the term “domestic waste” is intended herein to include all compositions, but of course the parameters of the process must be controlled to take into consideration the composition being treated. This, however, comes within the capabilities of skilled persons and requires no particular description, although some indication will be given later.
[0004] EP-A 136 277 A2 discloses an apparatus and method for gasifying what is called “biomass fuels”. A mass refractory layer has a first inclined fuel supporting ramp. A mass of refractory is provided opposing surface to define a primary gasification chamber. The chamber is sealed by another mass of refractory. Biomass fluid, heated by radiation from the refractory, carbonizes and releases volatile gases. Additionally, the apparatus comprises a lower refractory layer having a second inclined ramp, which has a plurality of inlet holes to provide air distribution in a specific combustion zone located below the zone in which carbonization occurs.
[0005] WO 96/00267 discloses a process in which waste is charged into a reactor, an oxygen-containing gas is injected into it, solid products and gaseous products produced by the treatment are withdrawn, and the treatment results from the successive passage of the waste through a heating and drying zone, a thermolysis zone, an oxidation zone and a cooling zone. In this application the control of the temperature to maintain it between 700 and 1400° C. is effected by controlling at least one of the parameters among the oxygen mass fraction and the mass fractions of the incombustible and the combustible components of the waste.
[0006] WO 99/37738 (some of the inventors thereof are the same as those of the preceding application) discloses a method of processing municipal wastes, primarily highly humid ones, which comprises drying, pyrolyzing and gasifying the waste by means of an oxygen-containing gas, at temperatures between 800 and 1300° C., by controlling the same parameters as are controlled in WO 96/00267, with the feature that the smoke gas, preferably a mixture with air, is used as the gasifying agent and the mass fractions of oxygen in said agent and of incombustible and combustible components in the waste satisfy a certain quantitative condition.
[0007] WO 99/42540 discloses a process for the gasification of biomass or biomass-comprising materials, which gasification takes place in a reverse-flow reactor in which the line of direction in which gas is passed through the biomass cuts the line of direction in which the biomass is supplied.
[0008] Japanese Application No. 07324432 discloses a burner for municipal refuse, wherein the temperature of the burning space of the burner chamber is raised to about 2000° C., then air is supplied and the temperature of the uppermost layer of a fuel packed bed is raised.
[0009] Japanese Application No. 10153892 discloses a gasification furnace for municipal waste divided by a partition plate into a first-stage gasification chamber for pre-heating and drying and a second-stage gasification chamber for obtaining partly oxidized gas.
[0010] The aforesaid and other prior art patents are not satisfactory for an efficient treatment of municipal wastes, for various reasons. Some of them do not permit continuous operation, or, if they permit it, it is very difficult to control it. The efficiency of their processes is limited. The structure and the operation of the reactors are complicated and expensive. Gas leakage problems are not considered, or if considered, are not adequately solved. The waste must be sorted according to composition and dimensions of particles before recycling.
[0011] This invention therefore has the purpose of providing a method and apparatus for the disposal of domestic wastes and the production of fuel gas from it that are free of the defects of the prior art methods and apparatus.
[0012] Another purpose of the invention is to provide such a method and apparatus that are adapted to continuous production.
[0013] A further purpose is to provide such method and apparatus that permit control of the feed of waste and of the rate of production in a full and adequate manner.
[0014] A still further purpose is to provide such a method and apparatus that are reliable in operation.
[0015] A still further purpose is to provide such a method and apparatus that are simple and economically convenient.
[0016] A still further purpose is to provide such a method and apparatus that prepares insert and metal materials for use.
[0017] Other purposes and advantages of the invention will appear as the description proceeds.
SUMMARY OF THE INVENTION
[0018] The method of the invention comprises;
[0019] a) providing a reaction space including a first, incomplete combustion zone, and a second, gasification zone;
[0020] b) feeding the waste to be treated to said reaction space at a controlled rate;
[0021] c) concurrently compacting said waste to form a stopper preventing leakage of gases from said reaction space;
[0022] d) feeding an oxygen-containing gas, preferably air, at a high temperature and under pressure to said incomplete combustion zone, whereby to effect incomplete combustion n of said waste; and
[0023] e) filtering the gases produced by said incomplete combustion through the solid material in the gasification zone, whereby to produce carbon monoxide and hydrogen.
[0024] In the incomplete combustion zone, besides the incomplete combustion of the waste, other phenomena may occur, including drying of the waste, evaporation of the water contained therein, and combustion of gases produced by the combustion of the waste.
[0025] The incomplete combustion of the waste will be called hereinafter “thermolysis” and the incomplete combustion zone will be called hereinafter “thermolysis zone”. In said zone there are produced carbon dioxide and a carbon-containing solid residue. The carbon contained in said residue reacts with carbon dioxide and water according to the well known reactions CO 2 +C=2CO and H 2 O+C=H 2 +CO.
[0026] The method of the invention also includes disposing of the ash that is the final product of the gasification. It may also include controlling the temperature in various parts of the reaction space by controlling the temperature of the oxygen-containing gas fed thereto, controlling the rate of feed of the waste and the resulting ratio of the waste feed to the oxygen-containing gas feed, and thermally insulating the reaction space. All the amounts of materials will be expressed herein as weight, unless otherwise specified. Persons skilled in the art may carry out other temperature-controlling operations that are conventional in themselves. Since the oxygen-containing gas is generally air, hereinafter reference will be made only to air for purposes of description, but this does not involve any limitation of the invention.
[0027] The regulation of the process is a function of the composition of the gas produced (e.g., according to the equilibrium constant) and the temperature of the reaction space. The regulation is effected by changing the waste feed rate and the amount of air supplied.
[0028] The invention further comprises an apparatus which includes:
[0029] A. a reaction chamber, which comprises a thermolysis zone and a gasification zone;
[0030] B. a feed vessel, hereinafter called “hopper”—in which term every possible shape and structure thereof is intended to be included—into which the waste to be processed is loaded;
[0031] C. waste feed means for advancing the waste from said hopper to said reaction chamber at a controlled rate and for compacting it concurrently;
[0032] D. at least two conduits for the waste advanced by said hopper, set at an angle—preferably a right angle—to one another;
[0033] E. an air chamber in communication with said reaction chamber;
[0034] F. a gas-receiving chamber for receiving the gases produced in the gasification zone of said reaction chamber, provided with an outlet for said gases; and
[0035] G. means for discharging the ash formed in said gasification chamber.
[0036] In a number of embodiments, the apparatus further comprises a cooling jacket surrounding the upper portion of said reaction chamber, while the gas-receiving chamber surrounds the lower portion of said reaction chamber. In another embodiment, the air chamber and the gas receiving chamber together surround the reaction chamber.
[0037] The waste feed means for advancing the waste from said hopper to said reaction chamber at a controlled rate and for compacting it concurrently, preferably consist of two pistons, coupled to two waste conduits. Since said conduits are at an angle to one another, generally at a right angle, the waste advanced by the first piston will reach the end of the first conduit and be stopped by the wall of the second conduit, whereby to form a stopper due to the pressure exerted by the first piston, said stopper being later advanced by the second piston into the said second conduit until it is discharged into the reaction chamber. The two pistons will be synchronized to carry out this operation, as will be explained hereinafter. While the aforesaid structure of the waste feed means is preferred, it is not limiting, and other mechanical arrangements can be devised by skilled persons within the scope of the invention
[0038] The apparatus of the invention further comprises, or is associated with, means for feeding the air under pressure to the air chamber. That pressure drives the gases throughout the apparatus, and particularly drives the combustion gases through the solid residue caused by the thermolysis of the waste.
[0039] The means for discharging the ash may be of any convenient mechanical structure, but preferably are similar to the aforesaid feed means, and comprise a piston, a conduit for the ash advanced by the piston, and an outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] In the drawings:
[0041] [0041]FIG. 1 is a schematic vertical cross-section of the apparatus according to an embodiment of the invention, taken on the plan passing through the axis of the reaction chamber;
[0042] [0042]FIG. 2 is a schematic view of the apparatus of FIG. 1 from above, portions of the top plate thereof broken off to show the underlying parts;
[0043] [0043]FIGS. 3A, B and C schematically illustrate various stages of the feed of waste material in the apparatus of FIG. 1;
[0044] [0044]FIG. 4 is a schematic cross-section at an enlarged scale of the thermolysis and gasification portion of the apparatus of FIG. 1 better illustrating its operation;
[0045] [0045]FIG. 5 is a schematic vertical cross-section similar to FIG. 1, but illustrating a second embodiment of the invention;
[0046] [0046]FIG. 6 is a schematic cross-section of the reaction chamber of FIG. 5 taken on plane VI-VI of FIG. 5;
[0047] [0047]FIG. 7 illustrates the apparatus of FIGS. 5 and 6 in operation;
[0048] [0048]FIG. 8 is a partial vertical cross-section of an apparatus according to a third embodiment of the invention;
[0049] [0049]FIG. 9 is a schematic cross-section of the reaction chamber of FIG. 8 taken on plane IX-IX looking in the direction of the arrows.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0050] With reference now to FIGS. 1 and 2, numeral 10 generally indicates the outer wall of the cooling and the gas-receiving chambers. The apparatus also comprises a top plate 11 and a partition plate 12 which define the air chamber 13 , said air chamber being provided with an inlet 14 for the hot air. Apertures 15 , which in this embodiment are generally hopper-shaped, having a broader upper portion and a narrower low portion, provide communication between said air chamber 13 and a cooling jacket 16 in which cooling air is circulated through outlet 17 and inlet 18 . The cooling of the thermolysis zone is especially necessary at the moment of heating, because highly energetic fuel burns at temperatures of 1200° C. and higher. Since when the operation of the apparatus starts, the waste to be treated must be heated from the outside until a correct operating temperature, preferably not more than 100° C., is reached, a hot gas may be temporarily circulated through jacket 16 instead of cooling air, or electrical or jacket means may be so temporarily employed.
[0051] A partition 19 separates cooling jacket 16 from a gas receiving chamber 20 provided with outlet 21 . A reaction chamber 22 is located below plate 12 and centrally of cooling jacket 16 and of gas receiving chamber 20 . The upper part of said reaction chamber is a thermolysis zone and the lower part is a gasification zone, but it should be understood that no precise border between said two zones exists or can be established. Actually, during the operation of the apparatus, the zone in which thermolysis ends and gasification begins may shift towards the top or the bottom.
[0052] The means for feeding the waste to be treated to the reaction chamber comprise a hopper 23 for receiving the waste 29 . Hopper 23 is coupled to a first conduit 24 (see FIGS. 3A, B and C) and discharges the waste into it. A piston 25 , only schematically indicated in FIGS. 1 and 2, is shown in three successive positions indicated as 25 a , 25 b and 25 C in FIGS. 3A, B and C. Piston 25 is initially in inactive position 25 a , but advances to position 25 b in conduit 24 when waste 38 has been discharged into conduit 24 . It is then advanced to position 25 c , below hopper 23 (see FIG. 3B), thus driving the waste along conduit 24 towards a second conduit 26 disposed at right angle to conduit 24 . As the waste reaches the junction 35 of the two conduits (see FIG. 2) its progress parallel to conduit 24 is stopped by the wall of conduit 26 and the waste is compacted there and forms a stopper 36 . A piston 27 , only schematically shown in FIG. 2, is shown in two successive positions indicated as 27 a and 27 b in FIGS. 3A, B and C. Piston 27 is initially in inactive position 27 a higher than conduit 24 (see FIG. 3B), but advances to position 27 b in conduit 26 (see FIGS. 3A and C) after waste 38 has been compacted into conduit 26 to form stopper 36 . In so doing, it drives said compacted waste—said stopper—along conduit 26 until it reaches opening 28 (see FIGS. 1 and 4), viz. the outlet of conduit 26 in the reaction chamber 22 . Concurrently, piston 25 retracts to position 25 b , to permit further waste to be discharged from hopper 23 into conduit 24 (see FIGS. 3A and C).
[0053] [0053]FIGS. 3A, B and C also illustrates what happens to any solid pieces of waste, such as that indicated at 37 . Said piece it is discharged from hopper 23 into conduit 24 (see FIG. 3A). When piston 25 advances to position 25 c , it may cut said piece into two fragments 37 ′ and 37 ″, one of which ( 37 ′) becomes part of stopper 36 and proceeds to the reaction chamber, while the other fragments ( 37 ″) is pushed back into hopper 23 , and may be further fragmented in successive strokes of piston 25 .
[0054] The operation of the device requires synchronization between the pistons 25 and 27 , as illustrated in FIGS. 3A, B and C. For clarity's sake, the stroke of piston 25 from position 25 b to position 25 c , towards conduit 26 , will be called the forward stroke, and its opposite stroke will be called the rearward stroke; and the stroke of piston 27 from position 27 a to position 27 b , towards reaction chamber 22 , will be called the forward stroke, and its opposite stroke will be called the rearward stroke. When piston 25 is withdrawn away from the junction 35 of conduits 24 and 26 , hopper 23 can discharge its contents into conduit 24 . Concurrently piston 27 can advance to its position closest to reaction chamber 22 and drive the stopper, which has been previously formed at junction 35 , towards said reaction chamber. Thereafter piston 27 will effect its rearward stroke and leave junction 35 free to receive the waste and concurrently piston 25 will effect its forward stroke, drive more waste to junction 35 and compress it there to form a new ash. Briefly it may be said that the synchronization is such that when one of the piston effects its forward stroke, the other piston effects its rearward stroke, and vice versa.
[0055] It will be clear that, though the pistons have an alternating motion and the waste is fed by portions, each portion being what was called a “stopper”, the operation of the apparatus is continuous for all practical purposes, as the portions can be made small enough and the frequency of the piston motion high enough, so that no overall discontinuity is felt. Additionally, as has been said, pistons 25 and 27 , and similarly pistons 25 and 41 or 52 and 54 , can fragment and/or cut off parts which can disturb the movement of the waste in the apparatus, viz., it may be said, can act as guillotines. In this sense the method and apparatus of the invention are said to be continuous. Of course, they could be made absolutely continuous by using other waste driving apparatus, e.g. of the screw extruder type, and skilled persons could easily substitute such apparatus for the one of the described embodiment.
[0056] It will be understood that the waste does not progress freely in a downwardly direction because of its weight. It is continuously driven by incoming waste and remains substantially compacted. The reaction chamber tapers towards the bottom, in frusto-conical shape, as seen in FIGS. 1 and 4, and this taper is such that the waste and the carbon-containing solid residues produced by thermolysis remain compact.
[0057] The thermal treatment of the waste is better illustrated in FIG. 4. The upper part of the reaction chamber 22 is a thermolysis zone 40 and the lower part is a gasification zone 41 . The two zones are not physically separated and their borderline, indicated in broken line in FIG. 4, may shift as the apparatus operates. The solid waste 38 enters the thermolysis zone from opening 28 of conduit 26 . Air is fed from the top, through conduit 14 , into a space between plates 11 and 12 and flows through openings 15 into the thermolysis zone. It then flows downwards through the waste and reacts with it, forming the fuel gases that are the final product and that flow out through outlet 21 .
[0058] The reaction chamber 22 has a lowermost portion 29 which tapers from top to bottom and is preferably frusto-conically shaped, as seen in FIGS. 1 to 7 . The lower opening 30 of reaction chamber 22 is located slightly above said portion 29 . The ash formed in the gasification chamber is discharged into said portion 29 and from there into a conduit 31 I(see FIG. 2). Said conduit 31 is coupled with a piston 32 which drives the ash towards an outlet 33 .
[0059] In FIGS. 5, 6 and 7 the parts that are identical or similar to parts of FIGS. 1 to 4 are indicated by the same numerals. The embodiment of FIGS. 5, 6 and 7 firstly differs from the previously described embodiment in that a pipe 40 , corresponding in its function to pipe 26 of FIG. 2, is positioned vertically, viz. a vertical plane and substantially perpendicular to feed pipe 24 and passes through a central opening of plate 12 . A piston 41 which has the same function as piston 25 of FIG. 2 is actuated within pipe 40 between an upper position 41 ′ (indicated in broken lines) and a lower position 41 ″. A stopper of waste forms at the junction 42 of pipes 24 and 40 , for the same reason and in the same way as it was formed at the junction 35 in the previous embodiment.
[0060] The embodiment of FIGS. 5 to 7 also differs from that of FIGS. 1 to 4 in that the reaction chamber, generally indicated at 45 , has a rectangular cross-section, as shown in FIG. 6.
[0061] In the embodiment of FIGS. 8 and 9, the feed of the waste occurs through hopper 50 and pipe 51 (said hopper and pipe actually merge into a single structure) and piston 52 . The waste is fed to a pipe 53 in which is displaceable a piston 54 . The piston 52 compacts the waste when this comes into contact with the wall of pipe 53 and forms a stopper. Piston 54 is vertically displaceable and in its downward stroke, pushes the stopper of waste into the reaction chamber which is generally indicated at 56 . In FIG. 8, piston 54 is shown in its lowermost position and there is no waste in pipe 53 , while the hopper has been refilled of waste. The functional relationship between piston 52 and piston 54 is the same as that between piston 25 and piston 27 in the embodiment of FIGS. 1 to 4 . So far, the present embodiment does not differ substantially from the embodiment of FIGS. 5 to 7 . In this embodiment the reaction chamber 56 is curved. Its axis is preferably an arc of circle, having a radius that depends on the properties of the waste treated and on the capacity of the apparatus. For example, for a waste gasification apparatus with the cacapcity of 0.6 ton/hr, the radius is in the range 2.1 to 2.8 meters. and subtending an arc of approximately 60 degrees. The reaction chamber has an upper section 56 ′ which is circumferentially limited by wall 58 having a circular cross-section and which extends to about one-half of the longitudinal, arcuate development of the reaction chamber. Below the wall 58 , the reaction chamber has a lower section 56 ″, which is uncovered at its concave side, while at its convex side it is limited by a wall having perforations 55 . The perforated wall covers from 27 to 33 degrees. The sections 56 ′ and 56 ″ of the reaction chamber are not physically separated and the passage from the one to the other changes with variations in the process parameters and, in each case, with time, so that it is not possible to mark a separating line in FIG. 8. An air conduit 60 surrounds the reaction chamber on its concave side and has the same cross-sectional, angular development as the uncovered portion of the reaction chamber section 56 ″. It receives air from opening 61 , at any suitable pressure, and the air is ejected through perforations 62 , so as to form between the conduit 60 and the reaction chamber an air chamber 63 . On the convex side of the reaction chamber, a gas settling chamber 64 is formed, which tapers into a gas conduit 65 terminating in a gas outlet 66 , from which issue the fuel gases produced, which are then collected and utilized in any convenient manner, not illustrated. At the lowermost portion of the reaction chamber, the spent waste accumulates into a conduit 67 . A piston 68 pushes the spent waste into said conduit, from which it is ejected by a piston 69 into discharge 70 , shown as broken off. The discharge of the spent waste or ash is essentially the same as in the previous embodiments and can be designed in the best way by persons skilled in the art.
[0062] In this embodiment, the waste stopper which is formed in pipe 53 and is pushed by piston 54 into the reaction chamber is heated, or better, pre-heated, in the upper section 56 ′ of the reaction chamber, viz. the section of the reaction chamber which is provided with a tubular casing. Since that section of the reaction chamber is in contact with the gas outlet conduit on one side and on the other side with the air chamber 63 in which air is generally introduced at a temperature well above room temperature, e.g., about 100° C., the waste becomes heated and thermolysis begins even though no air is fed into that section of the reaction chamber. Therefore, even before air comes into contact with the waste, it begins to undergo a thermolysis process. When it comes into contact with the air, fed through the openings 62 , the thermolysis of course increases, and is completed in the layer of the waste that is close to the air feed openings, the thickness, shape and borders of which layer are variable. The air issuing from openings 62 passes through the waste in a cross-sectional direction, forms partial combustion gases in the thermolysis zone and then completes the gasification in the gasification zone, which is the portion of the reaction chamber section 56 ″ that is interposed between the thermolysis zone and the orifices 55 , from which issue the fuel gases produced. The separation between the thermolysis and the gasifications zones is not fixed and can vary with variations of the process parameters and with the passage of time and therefore could not be marked in FIG. 8. The fuel gases therefore issue from orifices 55 and from them flow through gas settling chamber 64 , conduit 65 and outlet 66 . The progress of the waste through the reaction chamber and the discharge of ashes occur smoothly and gradually.
[0063] It should be understood that in an apparatus according to the invention, if the reaction chamber is vertical, there should be some restriction in it or some way of creating a resistance to the flow of the waste. In the preceding embodiments that resistance is created by the lower conical portion of the reaction chamber. In the embodiment of FIG. 8 it is created by the very shape of the reaction chamber. It could have been thought that in such a reaction chamber the waste would spill out on the uncovered part of the concave side and fill the space that is presently an air chamber 63 and occlude the orifices 62 . It is surprising that this is not so. The initial heating in zone 56 ′ of the reaction chamber has imparted to the waste a certain compactness, so that the waste remains more or less in the shape indicated in the drawing. On the concave side of the reaction chamber the waste may roll upon itself to some extent, forming a kind of superficial vortices, but it remains essentially in it general, regular shape and the formation of such vortices is only an advantage because it improves the contact of the air with the waste. The waste would not drop downwards by itself and if not subject to impulses from the piston (which is piston number 54 in FIG. 8), would remain unmoving. It is the combined and synchronized action of the various pistons that provides the smooth and substantially continuous motion of the waste and of the ashes and renders the apparatus extremely efficient and productive.
[0064] The reaction chamber has been described as having an axis that is an arc of circle. It should be understood that, while this is the preferred shape, it is not an exclusive one, and the shape, curvature radius and other geometrical parameters of the reaction zone may be changed by skilled persons if desired to obtain a smooth progress of the treated waste. Generally, it is preferred the axis of the chamber should be tangent to the vertical at its top and should subtend an arc close to 45 degrees at its bottom, viz. at the level at which the gas outlet orifices terminate, but these geometrical features are not compulsory and can be adjusted by skilled persons to obtain optimal progress of the waste.
[0065] It will be clear that, though the pistons have an alternating motion and the waste is fed by portions, each portion being what was called a “stopper”, the operation of the apparatus is continuous for all practical purposes, as the portions can be made small enough and the frequency of the piston motion high enough, so that no overall discontinuity is felt. Additionally, as has been said, pistons 25 and 27 or 52 and 54 can fragment and/or cut off parts which can disturb the movement of the waste in the apparatus, viz., it may be said, can act as guillotines. In this sense the method and apparatus of the invention are said to be continuous. Of course, they could be made absolutely continuous by using other waste driving apparatus, e.g. of the screw extruder type, and skilled persons could easily substitute such apparatus for the one of the described embodiment.
[0066] In an example of application of the invention, an industrial apparatus was built having dimensions 2×2×3 meters and heat output 1.0 MW. The apparatus had a capacity of 1 ton/hr of waste, consisting of 35 wt % of combustible materials, 50 wt % of humidity and 15 wt/o of incombustible materials. It produced a gas output of 2000 m 3 /hr, with a residue of 300 kg/hr.
[0067] While embodiments of the invention have been described by way of illustration, it will be understood that the invention may be carried out with many modifications, variations and adaptations, without departing from its spirit or exceeding the scope of the claims.
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Method of treatment of domestic waste. A reaction space is provided, into which the waste to be treated is fed at a controlled rate. The waste is concurrently compacted to form a stopper preventing leakage of gases from the reaction space. An oxygen-containing gas is fed to the reaction space, in order to affect the combustion of the waste and produce gases and solid material. The gas is filtered through the solid material, causing the gases to react with the solid material, whereby to produce fuel gases and ash.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit under any applicable U.S. statute, including 35 U.S.C. § 119(e), to U.S. Provisional Application No. 60/683,987 filed May 23, 2005, in the name of Dennis St. Germain, titled Sling Having Predictable Pre-Failure Warning Indicator and Associated Method.
This application incorporates by reference U.S. Provisional Application No. 60/683,987 as if fully set forth herein.
FIELD OF THE INVENTION
This invention relates generally to industrial slings used to lift, move and transport heavy loads and, more particularly, an apparatus for notifying operators/riggers who use synthetic slings of an overload or damage situation that may lead to sling failure.
BACKGROUND OF THE INVENTION
Wire rope slings made of a plurality of metal strands twisted together and secured by large metal sleeves or collars are common in the industry. During the past thirty years, industrial metal slings have seen improvements in flexibility and strength. However, compared to non-metal or synthetic fiber slings, metal slings are relatively stiff and inflexible.
Synthetic fiber slings have gained popularity over the last fifteen years and are replacing metal slings in many circumstances. Synthetic slings are usually comprised of a lifting core made of twisted strands of synthetic fiber and an outer cover that protects the core. The most popular design of synthetic slings is a roundsling in which the lifting core forms a continuous loop and the sling has a circular or oval-shaped appearance.
An advantage of synthetic slings is that they have a very high load-lifting performance strength-to-weight ratio which provides for a lighter, more flexible and even stronger slings than their heavier and bulkier metal counterparts. Even with such advances in the art of sling making, the riggers who use these improved synthetic slings still suffer and endure some of the age old problems of sudden failure and loss of a load caused by a sling breaking without warning because it was fatigued (or overly stretched) from being subjected previously to overload conditions. After a sling has been fatigued, it does not usually provide any physical indication that it was damaged—even to the trained eye. (One of the few advantages of a metal sling over a non-metal sling is that there is equipment available that can be used to conduct a non-destructive test of the metal. For example, similar equipment is routinely used to determine whether the wings of an airplane have become fatigued.)
Standard break tests have been established for determining how large of a load a sling can endure. Slings are attached to a testing machine that applies a steady but increasing force on the sling until it is unable to withstand the stress of the force being applied to it and the sling ultimately breaks. Such break tests have enabled manufacturers of industrial slings to rate the load-bearing capacity of the sling. The load capacity is determined to be a point well below the load used to break the sling and also below the point where the sling is fatigued or damaged. Most sling manufacturers will affix some type of tag notice on the sling which states the load capacity (rated capacity) of the particular sling. This rated capacity gives the maximum amount of load to which the sling may be subjected and still be considered a safe use of the sling.
Unfortunately, even conscientious operators/riggers who do not take unsafe shortcuts and who operate in a safe responsible manner sometimes are surprised by a sling breaking in use even when they believed it was being used within the load limits of its rated capacity. For example, when industrial slings are in continuous heavy use over three shifts around the clock, the operators on a later shift may not be aware that someone on an earlier shift had subjected the sling to a substantial overload which may have caused serious damage to the lifting core strands of the sling. When a synthetic fiber sling is overloaded beyond its tensile strength or weight-lifting capacity at maximum stretch, it is considered to be fatigued and may never return to its normal strength and load bearing capacity.
When subjected to an overload condition above its rated capacity, a roundsling can be permanently damaged/deformed if the load stretches the fibers of the load bearing core material beyond their yield point. An over-loaded sling may be susceptible to fracture at a stress point. This condition is similar to the stretching of a rubber band beyond its point of normal elasticity so that when the load or tension is removed or relieved, the rubber band will never regain its normal configuration and its strand dimensions may be permanently stretched which will cause it to fail under a load which is less than its tensile strength load. As stated previously, it is nearly impossible to determine, upon a cursory visual inspection, that a sling has been damaged because of the large size of such slings (on the order of 6 feet or more) and because the load-bearing core is hidden inside the outer cover.
Once the load-lifting core of the synthetic sling is stretched beyond its yield point, it can actually change in its physical structure and be restricted at a stress point. To date, there has been no precise method or apparatus available to an operator or rigger to determine if a sling with a protective cover was subjected to an overload or damage-causing condition. If a roundsling has been fatigued or structurally changed, the sling may no longer lift a load according to its maximum rated load capacity and, most importantly, becomes a serious threat to the operators and riggers using the sling.
Thousands of roundslings are being used on a daily basis in a broad variety of heavy load lifting applications which range from ordinary construction (e.g., skyscrapers and bridges), plant and equipment operations, to ship building (e.g., oil rigs), nuclear power plants and the like. The lifting core fibers of such roundslings may be derived from natural or synthetic materials, such as polyester, polyethylene, nylon, and the like. Although the outer covers of synthetic slings are designed to reduce damage, the core fibers are still susceptible to damage from abrasion, cutting by sharp edges, or degradation from exposure to heat, cold, ultraviolet rays, corrosive chemicals or gaseous materials, or other environmental pollutants.
In certain instances, the core yarn of a synthetic sling could weaken, melt or disintegrate when subjected to elevated temperatures, or to prolonged exposure to either ultraviolet light or chemicals. Still another safety concern flows from abuse by the user when the core yarn is damaged from abrasive wear when the slings are not rotated and the same wear points are permitted to stay in contact for extended periods of time with a device used for lifting (such as hooks on a crane), or on the edges of the load itself. Such abrasion is accelerated for certain types of synthetic fiber material and especially if the load contact section is under compression or is bunched. Riggers in the field are concerned that the inner lifting core yarn of their roundslings may be damaged on the inside without a means for them to detect such defects through the sling cover. Even if the cover is removed it may be impossible to tell if the lifting core has been damaged to the point where it cannot lift its rated load. Since there is no reasonable non-destructive testing techniques for synthetic fiber slings, a synthetic sling that is only suspected of being damaged must be removed from service for safety reasons.
The structural integrity of the roundsling lifting core material is difficult to determine when it is hidden inside a protective cover of opaque material which renders the lifting core yarn inaccessible for inspection. A stretched or fatigued roundsling could experience a sudden catastrophic failure without warning to the rigger, which may result in the loss of lives and property. Many in the industry have sought to provide safe slings to its riggers to avoid bodily injury, property damage and product liability claims.
Several roundsling constructions are known which have a failure indicator. For example, it is known in the art to incorporate a failure indicator synthetic strand as an integral member of the lifting or load-bearing core. The failure indicator strand in prior art constructions was always an extension of the core yarns.
A popular design of prior art roundslings was to twist a plurality of yarns together to form a single strand; the strand is then rolled into an endless parallel loops of strands that form the core, which is then encased in a protective cover material. If the sling was designed with a prior art failure indicator, an indicator strand would be incorporated into and twisted with the core yarns. The two ends of the indicator strand (sometimes referred to as tell-tails), extend freely through an opening in the cover material. When the sling is subjected to an overload condition, the tell-tail would partially withdraw within the cover and the freely extending tell-tail ends would be visibly shorter than the tell-tails of an undamaged sling; if the overload condition exceeded the maximum rated load of the sling, one or both tell-tails would usually withdraw completely within the cover. In either event, the rigger is warned of the occurrence of a potentially damaged sling by either the absence of one or both tell-tails, or a “significant” withdraw of at least one tell-tail inside the cover. However, there usually was no consistency on how the tell-tails would react when triggered, even when the slings were manufactured under identical conditions.
A drawback of prior art failure indicators based on an indicator strand is that there is no predictable way of determining when the failure indicator will be triggered. Synthetic slings have a safety factor designed into their construction. For example, if the sling is rated at 6,000 pounds, it typically will not be damaged unless the sling is subjected to a force five times greater (i.e., around 30,000 pounds, a 5-to-1 design factor) than the rated capacity; the tell-tail may be triggered and indicate an overload condition when the sling is subject to a force of between four to five times the rated capacity (i.e., about 24,000 lbs) by retracting into the sling's cover. Therefore, the tell-tail will provide a visual indication that the sling may have been damaged or subjected to a situation that may have been detrimental to the overall condition of the sling before the sling actually is subjected to such a condition. Unfortunately, there was no way of ensuring that the tell-tails would consistently withdraw within the cover at about 24,000 pounds.
In other words, two slings having prior art failure indicator strands contemporaneously made under the same conditions would have two different trigger points (for example, one sling may trigger at about 22,050 pounds and the other sling may trigger at about 26,000 pounds). In addition, one sling may react to a trigger event by completely withdrawing one of the tell-tails, while the other sling may react to a trigger event by partially withdrawing both tell-tails.
If the tell-tail is not withdrawn completely within the cover, one rigger's opinion of a “significant withdrawal” towards the opening in the cover may differ from another rigger's opinion. Therefore, a “small” movement of one or both of the tell-tails, which may result from the constant use and handling of the sling, may appear to one rigger as an indication that an overload condition was reached when, in fact, the sling was not subjected to an overload condition. Therefore, the visual inspection of the tell-tails in prior art failure indicators and the eventual determination of a trigger event becomes a subjective test.
Another prior art roundsling construction utilizes an optical fiber strand that enables the operator/rigger to test it by shining a light on one end of the optical fiber to determine if the light can be seen at the other end of the optical fiber. In U.S. Pat. No. 5,651,572 to Dennis St. Germain, it is taught to incorporate a flexible fiber optic “signal” cable into the lifting core strands of the roundsling.
As indicated previously, in a roundsling, the lifting core is configured in endless parallel loops of strands which are then encased within a protective cover material. The cover will have openings or orifice slits out of which the two ends of the fiber optic signal strand emerge. The aforesaid ends of the fiber optic cable are designed to extend freely through a slit in the sling's cover so that they are easily accessible by the rigger.
The optical signal strand member conducts light from a light source at one end to an observer looking at the opposite end for testing the integrity and the continuity of the core strands. The inclusion of the fiber optic cable in the lifting core yarn of the roundsling converts the inaccessible inner core area into an observable test check area by means of the passage of light through the fiber optic component of the lifting core.
Fiber optic materials are capable of transmitting light into endless parallel relationship with the fibers of the lifting core yarn. This fiber optic signal strand comprises fiber or rod material which permits the propagation of light that enters the fiber material at one end and is totally reflected back inward repeatedly from the fiber wall through the entire length of the fiber optic strand which enables the light being transmitted within the fiber optic cable to pass from one end of the fiber optic cable to the other end. If the light emerges at the other end of the fiber optic cable, it indicates that the integrity of the fiber optic cable throughout the path of the roundsling lifting core bundle is intact and, by reasoning, the integrity of the lifting core yarns are also intact.
Since the fiber optic cable member is incorporated into the lifting core of the roundsling disclosed in U.S. Pat. No. 5,651,572, it tends to develop somewhat similar breaking or snapping characteristics as the lifting core fiber materials. If the fibers of lifting core yarn break or fracture, then the fiber optic cable will also be damaged which will prevent the transmission of light from one end to the other end of the emerging fiber optic cable. If the light fails to pass from one end of the signal fiber optic cable to the other end, then the rigger is warned that the lifting core strands may be damaged, and to remove the protective cover from the roundsling for further inspection. If, upon inspection, it is determined that the roundsling was damaged, it will be immediately removed from service, and replaced with a new sling.
Although the apparatus disclosed in U.S. Pat. No. 5,651,572 is currently the leading product for determining whether the lifting core yarns of a synthetic sling have snapped or been damaged, in the stages where the sling has been subjected to an overload condition, the fiber optic signal strand still does not have the identical stretching properties of the load-bearing core yarns. Accordingly, unless the fiber optic cable breaks completely, some light may still be able to traverse the entire length of the fiber optic cable such that the degradation in the intensity of the light may be imperceptible to the naked eye.
Alternatively, the fiber optic cable, being more brittle than the synthetic core material, may be damaged by normal handling (and dropping) of the sling, or at a force less than the rated capacity of the sling. In such cases, the light transmission through the fiber optic cable may be disrupted causing the fiber optic cable to indicate an overload condition when, in fact, no overload condition was reached.
Finally, under other excessive or damage-causing situations (e.g., excessive heat, acidic or chemical exposure, and ultraviolet exposure) it can be expected that the fiber optic cable will be affected differently than the synthetic strands of the lifting core. If, for example, a sling with the fiber optic signal cable is exposed to certain chemicals, the fiber optic signal cable may be relatively unaffected (or only its exterior surface is affected leaving the light path through the center of the cable unscathed), while the lifting core has been degraded to the point where it no longer meets its load rating. Therefore, as stated previously, the need to precisely determine whether the load bearing core of a synthetic sling was subjected to an excessive or damage-causing situation still exists.
SUMMARY OF THE INVENTION
The present invention discloses a pre-failure warning indicator for use with a sling that is more accurate and predictable than prior art indicators. In the present invention, the failure indicator strand is separate and independent from the load-bearing core yarns.
One of the most popular designs of a roundsling is to twist a plurality of yarns together to form a single strand; the strand is then rolled into endless parallel loops of strands that form the core. In accordance with the present invention, a pre-failure warning indicator includes a separate dedicated strand of material, a ring made of a specially chosen material, and a separate warning fiber having an elongated indicator whip end.
The dedicated strand is placed proximate and substantially parallel to the loops of core strands of the sling; the ends of the dedicated strand are brought within close proximity (in a preferred embodiment several inches) to each other and are terminated with eyes or another configuration that can secure the ring. The ring is inserted through or secured to both eye terminations, thereby bridging the gap between the ends of the dedicated strand, and usually forms an oval-shaped loop. One end of the warning fiber is attached to one of the eyes of the dedicated strand, and the free end of the warning fiber is placed along the ring and threaded through the opposite eye; the free end of the warning fiber is then double-backed along the length of the ring. A tubular cover material encases the lifting core and the pre-failure warning indicator. The free end of the warning fiber extends through an opening in the cover material and is referred to as the indicator whip.
In a specific embodiment, a tag is attached to the strand (and preferably one of the terminating eyes) and is also drawn through the slot so that it extends freely outside the cover. The tag is designed to provide an indicator that the sling has been tampered with or sabotaged.
The ring is designed to fail when the sling is subjected to an excessive or damage-causing situation. A common damage-causing situation is when the sling is over-loaded. The ring will break when the sling is placed in an overload situation, thereby causing the termination eyes to separate, resulting in the complete withdrawal of the whip inside of the cover.
By choosing the ring carefully, relatively accurate predictions of the force needed to trigger the warning fiber can be made. In addition, the ring may be chosen to fail and thereby convey a damage situation when the sling is being used under unusual environmental conditions (e.g., excessively hot, acidic, or ultraviolet rays from, for example, sunlight).
Previous indicators either of the fiber optic nature or of the tell-tail type could give false indications of an overload or other internal damage. In the case of fiber optics, the ability to transmit light can be impeded by dirt, grease, and other debris that can retard the transmission of light through the fiber optic cable by jamming the ends. In the case of tell-tails, the movement of the sling's outer cover from friction with a load can give a false implication that the tell-tails were pulling under the cover when it was really the cover moving over the tell-tails. In the current invention, these areas of confusion are eliminated by a simple visual identification of the external warning indicator. Also, the dedicated strand can be locked into place by permanent attachment to the cover. If the cover shifts, the entire assembly of this invention moves with it in concert so a false indication of overload is eliminated.
Additional objects and advantages will be evident to one skilled in the art after a reading of the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and, together with the following description, serve to explain the principles of the invention. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred, it being understood, however, that the invention is not limited to the specific instrumentality or the precise arrangement of elements or process steps disclosed.
In the drawings:
FIG. 1 is a perspective view of a single-path roundsling which incorporates a predictable pre-failure warning indicator in accordance with the present invention;
FIG. 2 is an enlarged cross-sectional view of the roundsling illustrated in FIG. 1 taken along line 2 - 2 ;
FIG. 3 is a side view of a pre-failure warning indicator in accordance with the present invention;
FIG. 4 is a side view of another embodiment of a pre-failure warning indicator in accordance with the present invention, utilizing multiple rings linked together;
FIG. 5 is a side view of another embodiment of a pre-failure warning indicator in accordance with the present invention for use with a two-path sling;
FIG. 6 is a perspective view of a two-path sling incorporating the pre-failure indicator of FIG. 5 ;
FIG. 7 is a side view of a pre-failure warning indicator in accordance with the present invention which also incorporates a sabotage indicator means; and
FIG. 8 is a perspective view of a single-path roundsling incorporating the predictable pre-failure warning indicator of FIG. 3 and the sabotage indicator of FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In describing a preferred embodiment of the invention, specific terminology will be selected 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 that operate in a similar manner to accomplish a similar purpose.
The subject invention is an apparatus and method for determining whether a synthetic fiber sling has been damaged (because of an overload or other condition that could weaken the sling's load-bearing core) to a point where the sling should be removed from service and returned to the manufacturer for internal inspection and, if necessary, repair or disposal. Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings in which a roundsling having a pre-warning failure indicator in accordance with the present invention is generally indicated at 10 . The various preferred embodiments will be described with reference to the drawing figures that form a part of this description where like numerals represent like elements throughout.
FIG. 1 illustrates a perspective view of a roundsling in accordance with the present invention. FIG. 1 specifically shows a single-path roundsling, but the principles disclosed herein may be applied to other slings including multiple-path slings. FIG. 2 is a cross-sectional view of the roundsling shown in FIG. 1 taken along line 2 - 2 , and illustrates the primary interior components of a typical roundsling.
Referring to FIGS. 1 and 2 , the roundsling 10 comprises an inner core 12 encased within an outer protective cover 25 . The outer cover 25 shown in FIG. 2 is meant to convey that the cover 25 is larger than the load-bearing core 12 and moves relatively freely with respect to the load-bearing core 12 and not necessarily that the cover 25 has a cross-sectional shape of an oval. The core 12 is designed to bear the entire weight of the load to be lifted. The primary purpose of the outer cover 25 is to prevent physical damage to the core from abrasion, sharp edges on the load, etc.; the cover 25 will also help to reduce damage to the sling when it is used in an environment that will subject it to harsh elements such as heat, ultraviolet light, corrosive chemicals, gaseous materials, or other environmental pollutants. As will be explained hereinafter, the cover 25 can also be designed to notify a user when physical damage has occurred to the cover.
The lifting core 12 is preferably made of a single or multiple strands 17 configured in a plurality of endless parallel loops of strands to form a single core or multiple cores, all of which are contained inside the protective cover material 25 . The use of a single strand or multiple strands in this configuration is typical in the construction of roundslings.
The lifting core 12 of such roundslings may be derived from one or more natural or synthetic materials, such as polyester, polyethylene, nylon, K-Spec® (a proprietary blend of fibers), HMPE, LCP, para-aramid or other types of synthetics. The material chosen for the core primarily depends on the maximum weight the sling is designed to lift and environment in which the sling 10 will be used. Such sling constructions have a high lifting and break strength, lighter weight, high temperature resistance and high durability, compared to wire rope or metal chain slings.
Referring now to FIG. 3 , the pre-failure warning indicator 11 in accordance with the present invention is illustrated in side view and is shown without the cover 25 and without core 12 . In a preferred embodiment, the sling 10 may be manufactured with only a pre-failure warning indicator 11 , or with both a pre-failure warning indicator 11 and a tamper-evident means 35 . Initially, the operation of the pre-failure warning indicator 11 will be disclosed; the tamper-evident means 35 will be described later with respect to FIG. 7 .
A separate (preferably single) strand 20 of yarn is dedicated to the pre-failure warning indicator 11 . The dedicated warning strand 20 is located within cover 25 ; it is preferably placed proximate the core 12 and may either be twisted around the load-bearing strands of the core 12 or it may just lay next to the core 12 , as illustrated in FIG. 2 .
In a different embodiment, it may be desired to permanently affix the dedicated strand 20 to the inside of the cover 25 . When a sling is used over a period of time, the cover will develop wear points at specific locations, for example, where the sling hangs from a crane's hook. Accordingly, it is usually advisable to rotate the cover with respect to the load-bearing core 12 . By securing the dedicated strand 20 to the inner cover, movement of the cover (either intentionally or non-intentionally) will not affect the operation of the pre-failure warning indicator 11 .
First end 22 and second end 24 of the dedicated strand 20 are terminated in eyes 32 , 34 , respectively. The dedicated strand 20 and eyes 32 , 34 are preferably made of the same material as the core strands 17 .
The eyes 32 , 34 are connected by a ring 26 , thereby forming an endless loop with the dedicated strand 20 . The shape of the separate dedicated strand 20 generally matches the shape of the endless parallel loops formed by the core strand 17 (i.e., generally circular or oval). Although the term “ring” implies a circularly-shaped object, as used herein “ring” is defined as any closed link or band that will connect the ends of a dedicated strand.
In one preferred embodiment, the ring 26 is chosen to have a lower tensile strength than the core 12 . The sling manufacturer may choose to do this any number of ways, e.g., by making the ring 26 out of a different material than the dedicated strand 20 , cutting a notch or notches in the ring to physically weaken it, or by making the ring 26 out of the same material as, but of a smaller diameter than, the core strands 17 . When ring 26 is chosen to have a lower tensile strength, the pre-failure warning indicator 11 is designed to trigger and thereby notify the rigger or other users of the sling that the sling 10 has been subjected to an overload condition (i.e., the sling was subjected to a force that was pre-determined to compromise the integrity of the sling, and is sometimes determined to be about four times greater than the sling's rated capacity).
Attached to first termination eye 32 is a warning indicator fiber 29 . Warning indicator fiber 29 is an elongated strand that is placed substantially parallel to the ring, is threaded through the second termination eye 34 , is then double-backed along the ring 26 towards the first eye 32 , and directed out an opening in the sling cover 25 . (The external end 40 of the warning indicator fiber 29 that extends through the sling cover 25 is sometimes referred to as a “whip.”) Although the sling cover 25 is not shown in FIG. 3 , the preferred orientation of the warning indicator fiber 29 is illustrated, i.e., it forms a substantially “J” shape within the sling cover 25 .
Referring again to FIG. 1 , the whip 40 of the warning indicator 29 extends freely through cover 25 . Although not necessary, cover patch 30 may be attached (preferably by sewing), to the cover to protect the opening through which the whip end 40 of the warning indicator 29 extends.
The dedicated strand 20 is preferably made of similar material as the strands 17 of the load-bearing core 12 ; this promotes the relatively equal stretching of all components of the sling 10 . In a preferred embodiment, the ring 26 has a pre-selected lower tensile strength than the material used to make the core strands; in this embodiment, the ring 26 will fail before the lifting core 12 is stretched or fatigued. Alternatively—or in addition—the ring 26 may be designed to have a lower resistance to abrasion, heat, cold, and/or chemical exposure. By carefully choosing the properties of ring 26 , a sling manufacturer can control the condition(s) under which the subject pre-failure warning indicator 11 will trigger.
In one example, the sling manufacturer may design the ring 26 to fail at 70% of the tensile strength of the inner core. Accordingly, the material from which ring 26 is made and/or its cross-sectional thickness may be chosen to meet the pre-selected tensile strength.
When the sling 10 is placed under a load that exceeds its recommended rating, ring 26 will fail before damage can occur to either the load bearing core strands 17 that form the core 12 or the dedicated strand 20 . When ring 26 fails, the termination eyes 32 , 34 begin moving in opposite directions away from each other, and the physical distance between the eyes 32 , 34 and/or ends 22 , 24 of the dedicated strand 20 increases.
As the eyes 32 , 34 move apart, the whip portion 40 of warning indicator fiber 29 (i.e., the end that extends freely outside the cover 25 ) is drawn back inside the cover 25 until it no longer extends through the cover. If the whip end 40 of the warning indicator 29 is not visible, an inspector or rigger will immediately be able to determine that the sling 10 may have been subjected to a condition that would prevent the lifting core 12 from lifting its maximum rated load and will therefore remove the sling 10 from service for further inspection. The double-back configuration of the indicator fiber 29 ensures that the whip end 40 moves twice the distance compared to the distance the eyes 32 , 34 move apart, ensuring that every time a trigger event occurs, the whip end 40 will completely disappear. (It should be noted that the whip end 40 of the warning indicator 29 may be shaded in a high visibility color or otherwise marked, so that its visibility or lack thereof will be more noticeable.)
An important feature is that the ring 26 is designed to fail before damage occurs to the lifting core, thereby warning the riggers that they must either stop using the sling 10 in the manner in which they are using it or, if they continue, the sling 10 will be permanently damaged. If the rigger stops using the sling, the integrity of the lifting core 12 may remain intact. In this case, the sling 10 can be returned to the manufacturer and the pre-failure warning indicator 11 can be replaced or repaired; usually only the ring 26 will have to be replaced.
A primary advantage of the pre-failure warning indicator 11 in accordance with this invention is that the ring 26 may be designed to more precisely fail at a controlled point (regardless of whether it is at a specific strength, abrasion, temperature, etc.). The ring 26 can be used as an indicator of an overload condition by making it weaker than the individual core strands 17 . In a second embodiment, the ring 26 can be made from a material that would fail from yarn-on-yarn abrasion damage. In a third embodiment, the ring 26 can be made to fail from excessive temperatures (either heat or cold, or both). In a fourth embodiment, the ring 26 could be made from a material that would deteriorate in the presence of chemicals at a concentration lower than would damage the strands 17 of the load-bearing core. In still another embodiment, the ring 26 can be made of a material or combination of materials that would fail when subjected to more than one of the pre-determined conditions (e.g., overload and excessive heat).
In all of the above conditions, the ring 26 is preferably designed to fail at the pre-determined or desired condition at a relatively precise point. For example, if the sling is rated to lift 6,000 pounds (with a five-to-one design factor), the ring 26 can be designed to break relatively close to 24,000 pounds every time. Therefore, the ring 26 can be made to fail before the built-in safety factor of 30,000 pounds and well before any damage occurs to the sling 10 . The use of the predictable pre-failure warning indicator 11 as disclosed herein, gives a sling manufacturer a more predictable and accurate way of incorporating a failure notification means into any sling it designs or makes. In other words, the present invention introduces a degree of predictability into the manufacturing of roundslings since the failure point of the ring 26 can be selected and consistently reproduced. In prior art tell-tail indicators, the failure point was unpredictable and was not consistently reproducible.
A prototype was made in order to meet the following requirements:
Tensile strength of 30,000 lbs.; Vertical Rated Capacity=6,000 lbs. at a 5 to 1 design factor; Overload Warning Indicator triggers at 20,000-25,000 lbs. with a Design Factor between 3 & 4 to 1; Lightweight: 6′ prototype weighs 1.7 lbs; Double contrasting color cover: Outer Green and inner Red for easy cut inspection; Low stretch; Impervious to salt water and most chemicals including oil, diluted acids and bases;
Made with K-Spec® proprietary blend of high performance core yarn.
The above prototype was tested and it was determined that the whip 40 of the pre-failure warning indicator 11 consistently disappeared (meaning that ring 26 consistently broke) at between 23,000 and 24,000 lbs and the final tensile strength of the sling 10 was 32,860 lbs.
When the whip 40 of the warning indicator 29 is no longer visible, the sling 10 should be returned to the sling manufacturer for inspection and/or repair. The ring 26 consistently broke before damage occurred to either the dedicated strand 20 or the load-bearing core 12 . In many cases, the sling manufacturer will only have to replace the ring 26 in order to refurbish the sling and return it service. (In the above example, the ring 26 failed around 24,000 pounds and the sling 10 did not approach its maximum tensile strength of 30,000 pounds.) Under certain conditions, even though the ring 26 may have been designed to fail first, the sling 10 may have degraded to a point where it must be discarded entirely. For example, if the sling 10 was exposed to an acidic environment for an extended period of time, especially after the ring 26 failed, the sling 10 (and, specifically, the strands 17 that make up the load-bearing core) may have been damaged to such an extent that it can no longer meet its rated capacity. (The selection of the material for the core is the primary factor in determining whether the subject sling is impervious to sea water, oil, acids and other chemicals. Also, the cover 25 plays an important factor in protecting the core especially from abrasion or from sharp edges.)
It should be noted that a person skilled in the art, after reading the present disclosure could produce equivalent embodiments. For example, even though virtually all synthetic slings have a load-bearing core protected by an outer cover, a sling manufacturer can eliminate the outer cover (or shorten the outer cover) so that the ring 26 is visible. In this embodiment, a dedicated strand is not required and an operator can determine that a sling overload condition (or other failure condition) was met by observing the integrity of the ring 26 .
Referring now to FIG. 4 , another preferred embodiment is disclosed. In this embodiment, pre-failure warning indicator Ha incorporates a plurality of rings 26 a , 26 b , 26 c , etc. connected together (i.e., as links in a chain) between termination eye 32 and termination eye 34 . In this manner, a sling 10 a can be designed to indicate whether it has been subjected to multiple excessive conditions—any one of which could cause the controlled destruction of one of the linked rings 26 a , 26 b , 26 c , etc. and which would then trigger the warning indicator 11 a in a similar manner as when there is only one ring 26 . (Although this example uses three rings 26 a , 26 b , and 26 c , two rings, four rings or more rings may be used depending on the number of failure conditions the sling manufacturer wishes to incorporate into the sling.)
The warning indicator fiber 29 has a secured end and a whip end. The secured end is attached to one termination eye 32 ; the remainder of the indicator fiber 29 is placed along all of the rings 26 a , 26 b , 26 c ; the indicator fiber is then threaded through the other termination eye 34 , is double-backed along all the rings, and is finally directed through the slit in the cover 25 where the whip is visible to an operator.
For example, as shown in FIG. 4 , ring 26 a could be designed to fail when the sling is subjected to an overload (excessive weight) condition, ring 26 b could be designed to fail under an excessive heat condition, and ring 26 c could be designed to fail when exposed to a specific concentration of a particular chemical. Therefore, if the sling is subjected to any of the pre-determined failure conditions, one of the rings 26 a , 26 b , 26 c will fail, causing the termination eyes 32 , 34 to pull away from one another, thereby causing the whip portion 40 of the warning indicator whip 29 to completely retract inside the cover 25 . In this manner, a single predictable pre-failure warning indicator 11 c can be used to signal one of a multiple possible failure conditions. By marking the individual rings before assembly of the sling, one can determine the exact condition which the sling was subjected to that caused the pre-failure warning indicator to trigger. So, for example, if ring 26 b failed (and ring 26 a and ring 26 c remained intact), the sling manufacturer would know that the sling was subjected to a high temperature for an extended period of time.
An improved synthetic roundsling having multiple cores is manufactured by Slingmax, Inc. and is disclosed in U.S. Pat. No. 4,850,629 to Dennis St. Germain. An embodiment disclosed in U.S. Pat. No. 4,850,629 is a two-core roundsling (sold under the brand name TWIN-PATH®) which has two-load lifting cores inside a single cover. The cover is also divided into two separate paths. U.S. Pat. No. 4,850,629 is incorporated by reference as if fully set forth herein.
Similar to a sling having a single core (and a single pre-failure warning indicator), in a multiple-core or multiple-path roundsling 50 , each core incorporates a predictable pre-failure warning indicator 11 a , 11 b , as taught herein. Referring now to FIG. 5 , a first dedicated strand 20 a is associated with the first core 12 a of a two-path sling 50 and a second dedicated strand 20 b is associated with the second core of the two-path sling. The dedicated strand 20 a is terminated by termination eyes 32 a , 34 a , and dedicated strand 20 b is terminated by termination eyes 32 b , 34 b , respectively. A ring 26 d , 26 e , as disclosed previously in a one-path sling 10 , is incorporated into each path of the two-path sling 50 .
Referring now to FIG. 6 , whip 40 a is associated with the predictable pre-warning indicator 11 a in the first path of the sling 50 , and whip 40 b is associated with the predictable pre-warning indicator 11 b in the second path. (It should be noted that the warning indicator fiber 29 a is attached to one termination eye 32 a , threaded through the other termination eye 34 a , and the whip end 40 a is passed through the cover 25 a , and operates in a similar manner as the “basic” single-path sling 10 illustrated in FIGS. 1 through 3 using only one ring 26 . Similarly, warning indicator strand 29 b is attached to one termination eye 32 b , threaded through the other termination eye 34 b , and the respective whip end 40 b is passed through the cover, and operates in a similar manner as when there is only one ring 26 .)
Sling 50 is comprised of a two-path core; as illustrated in FIG. 6 the warning indicator whips 40 a and 40 b are passed through the cover 25 a and emerge in free extension apart from the cover 25 a . This embodiment provides a pre-failure indicator for each path that can convey sling damage or overload when either core of the TWIN-PATH® sling is subjected to a load which exceeds its tensile strength or rated capacity. When this happens, one or both of the extended warning indicator whips, 40 a and/or 40 b , which emerge outside of the cover material 25 a will retract completely within the cover thereby alerting the operator or rigger to a sling overload condition.
In a Twin-Path® sling having exactly two cores, each core is identical to the other. Referring again to FIG. 5 , an interesting variation for a two-core sling is the ability to design into the sling two distinct and separate damage-indicating parameters into a single sling. For example, in the first path, the ring 26 d could be designed to fail only at a lower tensile strength than the core 12 ; while in the second path, the ring 26 e could be designed to fail only when the sling is exposed to a certain chemical in the environment. The whips 40 a , 40 b of warning indicators 29 a and 29 b can be marked or coded in order to indicate which whip is associated with which ring so that if a ring breaks, the rigger will know the condition that was exceeded (i.e., if ring 26 d breaks it was because the TWIN-PATH® sling was subjected to a load approaching it's maximum load rating; alternatively, if ring 26 e breaks if was because the TWIN-PATH® sling was exposed to the chemical for a period of time such that it deteriorated the integrity of the sling). Therefore, if a three-core sling is made, three separate conditions may be simultaneously and independently tested using the predictable pre-failure indicator 11 taught herein; a four-core sling can be used to simultaneously test for four separate conditions, etc.
In this manner, if the two-path sling 50 is subjected to either one of the pre-selected conditions to a point that causes either ring 26 d or ring 26 e to fail, the rigger will be alerted and will have more information than would otherwise be available to him. Designing the rings 26 d , 26 e to fail under different situations may also assist the sling manufacturer in analyzing the sling or further improving the sling, if the sling is ever returned for inspection or repair. However, there are situations in which it will be necessary to design the rings 26 d and 26 e to fail under the same condition (e.g., an overload condition).
The pre-failure warning indicator 11 in accordance with the present invention is designed with a trigger mechanism that will generate a magnified force on the whip end 40 of the external warning indicator 29 in order to move the whip end 40 out-of-sight almost instantaneously, if any of the pre-engineered conditions are met and the ring fails. The reason why the force on the whip end 40 of the warning indicator fiber 29 is magnified is because of the double-back design of the warning indicator fiber 29 through the termination eyes 32 , 34 . After the ring 26 breaks, the termination eyes 32 and 34 separate at a certain speed; however, since the warning indicator fiber 29 is tied to one eye 32 , threaded through the opposite eye 34 , and doubles-back along the ring before emerging through the cover 25 , the whip end 40 of the warning indicator is moving twice as fast (and twice the distance) as the speed (and distance) at which the eyes 32 , 34 are moving away from each other. Accordingly, the whip end 40 withdraws inside the cover entirely so that there is no question as to whether a trigger event occurred.
Another feature to note, is that because the whip 40 of the warning indicator 29 is moving so fast, it creates a sound that is audible to the operator. Therefore, the present invention not only gives a visual indication that a sling has reached a critical damage point, but also gives an audible warning. The audible warning is especially important when the sling is positioned so that the operator cannot see the whip 40 (e.g., when the sling is hanging thirty feet in the air).
Another notable feature of the subject pre-failure warning indicator 11 is the ability to warn the rigger of an overload and other dangerous situations without affecting the overall strength of the roundsling 10 . If the rigger stops lifting the load promptly after the pre-failure warning indicator 11 is triggered, the sling 10 retains 100% of its residual strength.
The color code safety feature of this invention may be achieved by encasing the load-bearing core in two separate covers, each cover having a different color. For example, the outer cover could be green or blue, and the inner cover could be orange or red; since the inner cover is a different color from the outer cover, it will show through whenever the outer cover is cut or worn through. This double-cover feature provides a visible safety warning for any user of the sling that abrasion or other damage not normally detectable, has occurred.
In another embodiment of the present invention, a pre-failure warning indicator 11 can be adapted with a sabotage or tamper-evident means. Referring now to FIG. 7 , a tamper-evident tag 35 is attached to either the dedicated indicator strand 20 or, preferably, to one of the eyes 32 or 34 . The free end of the tamper-evident tag 35 is passed through the cover via a slit. The slit can be the same one through which the whip 40 passes through.
If the pre-failure warning indicator 11 is triggered (by, for example, an overload condition), this means that ring 26 has been broken, the ends 22 , 24 of the dedicated strand 20 are free, causing whip 40 to withdraw completely within the cover. Upon inspection, the tamper-evident tag 35 can be easily pulled out from inside the cover 25 along with a portion of the dedicated strand 20 , as illustrated in FIG. 8 , when the pre-failure warning indicator 11 has been triggered. If the whip end 40 of the warning indicator is not visible because of an intentional intervention by a user, the tamper-evident tag 35 will remain secure and cannot be pulled from the cover 25 . In this manner, sabotage of the sling 10 can be evidenced by the supervisor on the work site. (In order to avoid work, some users will cut off the whip end 40 of the warning indicator 29 in an attempt to make it appear that the sling was subjected to a damage situation and, therefore, work must be temporarily stopped so that the sling can be removed for inspection and, if necessary, replaced with a new sling.)
As part of the inspection process, the inspector may yank on the tamper-evident tag 35 . If the tag is secure, the sling 10 is useable; but, if the tamper-evident tag 35 can be pulled out from inside the cover, the sling 10 must be removed from use because the pre-failure warning indicator 11 has been triggered. Of course, if a saboteur cuts both the whip end 40 and the visible portion of the tamper-evident tag 35 , the inspector will immediately know that the sling 10 has been tampered with, and should remove the sling from service.
It is important to note that no other prior warning indicators have the ability to quickly inspect the condition of a roundsling. Also, prior warning indicators are not as accurate as the subject warning indicator 11 . If the whip end 40 of the warning indicator is visible and the cover 25 is intact, the roundsling can be used for the next lift; if the whip end 40 of the warning indicator is not visible, the sling should be removed from service and inspected. The subject pre-failure warning indicator is the first completely pass/fail inspection system—it is a completely objective test and not subjective.
It should also be noted that one skilled in the art, after reading this disclosure, may develop variations that are contemplated as being equivalent in scope to the various embodiments specifically set forth in the present disclosure. For example, the termination loops 32 , 34 may be eliminated and the ends of the dedicated strand 20 may be tied directly to the ring 26 . (Alternatively, slip-knots or other means may be used to secure the ends of the strand 20 to the ring 26 .) Although this invention has been described and illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that various changes, modifications and equivalents may be made which clearly fall within the scope of this invention. The present invention is intended to be protected broadly within the spirit and scope of the appended claims.
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A pre-failure warning indicator is provided for use with a sling. The pre-failure warning indicator triggers at a point that is predictable within a relatively narrow range, thereby increasing the possibility that a damaged sling is removed from use. The pre-failure warning indicator includes a dedicated strand of material that is placed in close proximity to the load-bearing core yarns of the sling but remains separate and independent from the core yarns; the ends of the dedicated strand are connected via a sacrificial “ring.” A warning fiber having an end that is visible to operators/riggers works in conjunction with the sacrificial strand and the ring. The ring is designed to fail when the sling is subjected to a specifically chosen condition (e.g., excessive weight). The failure of the ring causes the warning fiber to withdraw from the rigger's view thereby warning the rigger that the sling was subjected to the specifically chosen condition and may be damaged.
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DESCRIPTION
1. Technical Field
This invention relates to a suspended seat assembly and more particularly to a compact suspended seat assembly having reduced elevational space requirements.
2. Background Art
Suspended seat assemblies suitable for use on a vehicle, for example a lift truck, earthmover and the like have been proven superior in both ride and comfort as compared to a standard seat assembly of the non-suspended type. However, use of seat assemblies of the suspended type has been limited due to the substantial amount of elevational travel of the seat between a fully raised position and a fully lowered position. This is particularly true in vehicles wherein an overhead structure such as a cab or overhead guard is provided. Usually, the overhead structure is at preselected maximum distance from the ground upon which the vehicle operates, thus preventing an increase in the height of the overhead structure and the distance between the seat and the overhead structure. Therefore, inadequate clearance between the head of the vehicle operator and the overhead structure prevents the use of existing suspended seat assemblies.
Typical suspended seat assemblies as discussed above are disclosed in U.S. Pat. Nos. 2,714,001 to A. J. Hersey et al, dated July 26, 1955; 2,834,396 to E. A. Herider et al, dated May 13, 1958; 3,049,330 to R. R. Coons et al, dated Aug. 14, 1962; 3,137,473 to A. G. Augunas dated June 16, 1964; and 4,047,759 to D. P. Koscinski dated Sept. 13, 1977. These seat assemblies all have a common deficiency in that at least one member of the suspension system, i.e. link, spring, or cylinder is connected to the seat frame and support frame at a location which interferes with the seat frame and prevents it from passing the support frame. Thus, in order for the suspension system to perform in an optimum manner the seat frame must be spaced a greater distance from and above the support frame than desired.
The range of occupant weight which the suspension seat assembly is to accommodate is related to the suspension spring rate, the linkage geometry, and the amount of elevational travel of the seat assembly. Usually, the greater the amount of elevational seat assembly movement the broader the weight range capacity. This is due to the spring being stretched or compressed a greater amount when seat travel is large. Therefore, prior art designs required a large amount of elevational movement of the seat assembly in order to successfully accommodate a broad range of operator weight. As a result the suspended seat assemblies were applicable for use where seat travel distance was not restricted.
Suspended seat assemblies are particularly suited for use on vehicles where the suspension system is relatively stiff and the terrain is rough. Suspended seats respond to these rough vehicle motions and smooth out the ride for the occupant seated thereon. Typically, the seat will oscillate through a substantial number of cycles in a relatively short period of time resulting in premature wear and improper adjustment of the seat assembly. This is particularly evident in prior suspended seat assemblies which utilize complicated suspension systems having long links and a substantial amount of elevational seat travel.
The present invention is directed to overcoming one or more of the problems as set forth above.
DISCLOSURE OF THE INVENTION
In one aspect of the present invention, a suspended seat assembly is provided which includes a support frame having first and second spaced apart support members, a seat frame having first and second spaced apart sides positioned adjacent the first and second support members, respectively; a connecting apparatus pivotally secures the first side to the first support member and the second side to the second support member and permits elevational movement of the seat assembly between a first position spaced above the support frame, past said first and second support members, to a second position spaced below the support frame; a tie apparatus maintains the first and second sides at a preselected attitude relative to the respectively adjacent first and second support members and a biasing arrangement located adjacent one of the first and second sides and elevationally above the respectively adjacent one of said first and second support members biases the connecting apparatus and urges the support frame to the first position.
Therefore, the suspended seat assembly of the subject invention is compact, permits usage in applications wherein elevational movement is limited due to the ability to move past the seat frame to a location therebeneath, reduces wear and frequent adjustment due to simple construction, and is able to accept a wide range of vehicle operator weights due to the position and geometry of the connecting apparatus, tie apparatus and resilient device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic side elevational view of an embodiment of the present invention showing the suspended seat assembly in solid lines at a mid elevational location in phantom lines at the fully raised and fully lowered positions, portions of the structure are broken away for better clarity;
FIG. 2 is a diagrammatic top elevational view of the suspended seat assembly of FIG. 1 with portions broken away to show the suspension linkage and associated components; and
FIG. 3 is a diagrammatic front elevational view of the seat assembly of FIG. 1 with portions broken away to show the transverse location of the suspension linkage and associated components.
BEST MODE FOR CARRYING OUT THE INVENTION
With reference to the drawings, a suspended seat assembly 10 has a seat frame 12, and a support frame 14. The seat frame 12 has first and second spaced apart substantially parallel rectangular shaped elongate sides 16 and 18 and a rectangular shaped bottom portion 20. A seat cushion 22 of a conventional construction is positioned between the sides 16 and 18, supported on the bottom portion 20 and secured to the bottom portion in any suitable fashion, such as by threaded fasteners (not shown). A seat back 24 of a conventional well known construction is adjustably connected to the seat frame 12 and angularly positionable relative to the seat cushion to provide proper support for the back of an occupant seated on the cushion 22.
The support frame 14 has first and second spaced apart parallel elongate support members 26 and 28. These support members are connected to a pair of adjustable spaced apart rail assemblies 30 positioned therebeneath by fasteners 32. The rail assemblies 30 are secured to a portion of a vehicle 34, such as the prime mover top cover of a lift truck, in any suitable fashion. These rails provide fore-aft adjustable movement of the seat assembly relative to and along a longitudinal center line 36 of the vehicle so as to permit proper orientation of the operator seated thereon relative to the controls of the vehicle. The first support member 26 is positioned closely adjacent the first side 16 and the second support member 28 is positioned closely adjacent the second side 18. Both sides 16 and 18 are located transversely between the first and second support members 26 and 28 so as to permit elevational movement of at least portion of the seat assembly 10, i.e.; sides 16 and 18, between a first location 38 spaced elevationally above the first and second support members 26 and 28, past the support frame 14 to a second location 40 spaced elevationally below the support member 26 and 28.
A connecting apparatus 42 is provided for pivotally connecting the first side 16 to the first support member 26 and the second side 18 to the second support member 28 and permitting elevational movement of the seat frame 12 between the first location 38 and the second location 40. The connecting apparatus 42 has first, second, third and fourth support links 44, 46, 48 and 50 which are preferably triangular shaped bellcranks of plate steel. The links each have first, second and third spaced apart end portions 52, 54 and 56. The first and second links 44 and 46 are positioned between the first side 16 and the first support member 26 and pivotally connected at the first end portion 52 thereof to the first side 16 at spaced apart locations on the first side 16 and pivotally connected at the second end portion 54 thereof to the first support member 26 at spaced apart locations on the first support member 26. The third and fourth links 48 and 50 are positioned between the second side 18 and the second support member 28 and pivotally connected at the first end portion 52 thereof to the second side 18 at spaced apart locations on the second side and pivotally connected at the second end portion 54 thereof to the second support member 28 at spaced apart locations on the second support member 28. Preferably, the spaced apart locations on the first and second support and side members 26, 28, 16 and 18 are front 58 and rear 60 end portions of those members.
A pivot pin 62 is connected to the first and second end portion 52 and 54 of each link 44, 46, 48 and 50 and rotatably disposed in an aperture 64 located at the front and rear end portions 58 and 60 of the first and second side and support members 16, 18, 26 and 28. A bushing 65 is provided between the pivot pin 62 and aperture 64 of the first and second end portions 52 and 54 of each link 44, 46, 48 and 50.
A tie apparatus 66 controllably maintains the first and second sides 16 and 18 at a preselected attitude relative to the respectively adjacent first and second support members 26 and 28. The tie apparatus 66 preferably maintains the sides 16 and 18 parallel to the support members 26 and 28 throughout the range of elevational movement of the seat assembly 10. Specifically, the tie apparatus 66 includes a first 68 and a second 70 tie rod each having opposite ends 67 and 69.
The first tie rod 68 extends between the first and second links 44,46 and is connected at one end portion 67 to the third end portion 56 of the first link 44 and at the other end portion 69 thereof to the second link 46 at a predetermined location between the second and third end portions 54 and 56 thereof. The second tie rod 70 extends between the third and fourth links 48 and 50 and is connected at one end portion 67 thereof to the third end portion 56 of the third link 48 and at the other end portion 69 thereof to the fourth link 50 at a predetermined location between the second and third end portions 54 and 56 thereof. These tie rods synchronize movement of the first and second links and movement of the third and fourth links so that pivotal movement of any one of the links will result in an equal amount of pivotal movement of its associated interconnected link.
The tie apparatus 66 also includes a cross shaft 72 securely connected at opposite spaced apart end portions 71 and 73 thereof to the second end portion 54 of the second and fourth links 46,50, respectively, extends transversely between the first and second 26,28 support members and is pivotally connected at opposite end portions thereof to the rear end portion 60 of the first and second support members 26,28, respectively. The cross shaft 72 maintains the second and fourth links 46 and 50 at a preselected attitude relative to one another so that pivotal movement of either link results in an equal amount of pivotal movement of the other. It is to be noted that the seat assembly 10 is elevationally spaced above the cross shaft 72 at the first position 38 of the seat frame 12 and movable past the cross shaft 72 to the second position in response to pivotal movement of the links 44,46,48,50. It can thus be seen that the tie rods 68 and 70 and the cross shaft 72 are all interconnected so that pivotal motion of any one link results in an equal amount of pivotal movement of all links in the same direction. It should be noted that the cross shaft 72 as presented herein also serves as the pivot pin since it pivotally connects the second end portion 54 of the second and fourth links to the rear end portion 60 of the support members 26 and 28.
A biasing arrangement 74 cooperates with the connecting apparatus 42 and urges the seat frame 12 to the first elevational location 38. The biasing arrangement 74 is located adjacent at least one of the first and second sides 16 and 18 and elevationally above a respectively adjacent one of said first and second support members 26 and 28. The biasing arrangement 74 preferably includes a tension spring 76 having opposite end portions 78 and 80 and a linear gas spring 82 having a rod 84 slidably disposed in a cylinder 86 and biased to extend from the cylinder 86. One end portion 78 of the tension spring 76 is connected to the third end portion 56 of the first link 44 and the other end portion 80 of the tension spring 76 is connected to the first support member 26 via an adjustable connecting apparatus 88. The cylinder 86 of the gas spring 82 is connected to the third end portion 56 of the fourth link 50 and the rod 84 is connected to the second support member 28 via bracket 89. It is to be noted that the connections of the tension spring 76 and gas spring 82 heretofore discussed are preferred, however, connection to other links would be appropriate provided the springs 76 and 82 do not pass between the support and seat frames 12 and 14 and the seat cushion 22.
The links 44, 46, 48 and 50, springs 76 and 82 and tie rods 68 and 70 are located substantially outboard of the seat frame 12 so as to permit the seat frame 12 to pass the support frame 14 and thereby reduce the magnitude of elevational movement above the support frame 14. The springs 76 and 82 are preferably oriented substantially parallel to the longitudinal centerline 36 of the seat assembly 10, elevationally above the respectively adjacent first and second support members 26,28 and substantially between a plane 90 projection vertically from the respectively adjacent ones of the first and second sides 16 and 18 and a plane 92 projecting vertically from the respectively adjacent ones of the first and second support members 26,28. Thus, the tie rods 68 and 70, springs 76 and 82 and connecting links 44, 46, 48 and 50 assume a low, compact profile outboard of the seat frame 12.
The adjustable connecting apparatus 88 provides the function of selecting the range of operator weight which the suspended seat assembly 10 will comfortably and effectively support. The connecting apparatus 88 connects the other end portion 80 of the spring 76 to the first support member 26 and controls the amount of force applied to the first link 44. The adjustable connecting apparatus 88 includes an adjustment rod 94, a handle 96 and a pivot lever 98. The adjustment rod 94 has a threaded end portion 100 and connecting link end portion 102. The pivot lever 98 has a first end portion 104 pivotally connected to the first support member 26 and a second end portion 106 hookingly connected to the other end portion 80 of said tension spring 76. The connecting link end portion 102 is connected to the pivot lever 98 and the threaded end portion 100 is slidably movably disposed in an aperture 108 of a flange 110. The flange 110 is securely connected to the first support member 26. Handle 96 is screwthreadably mounted on the threaded end portion 100 and movable therealong into forceable contact with the flange 110 for adjusting the tension spring 76. It is to be noted that the adjustable connecting apparatus 88 is located outboard of the seat frame 12 is compact, has a low profile, and does not interfere with elevational movement of the seat frame 12 past the support frame 14.
A first and second shroud 112 and 114 of preferably a nonmetallic plastic material is positioned in a covering relationship with the connecting apparatus 42, tie apparatus 66, biasing arrangement 74 and adjustable connecting apparatus associated with the first and second support frames respectively. The first shroud is secured to the first support member 26 by fasteners 116 and the second shroud is secured to the second support member 28 by fasteners 118.
Industrial Applicability
In operation and with reference to the drawings, the suspended seat assembly 10 in an unloaded unoccupied condition will be positioned at the fully raised first elevational location 38. At this location the suspension links 44,46,48,50 first end portion 52, and at least a portion of the seat frame 12, will be located elevationally above the support frame 14 and the force applied to the connecting apparatus 42 by the gas and tension springs 82 and 76 will be at a minimum.
Upon occupancy of the seat assembly by a vehicle operator, the links 44, 46, 48 and 50 will each pivot, under the influence of the occupant's weight, about their first and second end portion 52 and 54 in unison, clockwise, to a mid-location (as shown in FIG. 1) elevationally spaced below the first elevational location 38 but above the second elevational location 40. At this mid-location, the force applied by the tension spring 76 and gas spring to the connecting apparatus will be adequate to offset the weight applied to the seat 22, i.e. the system will be in equilibrium. It is to be noted that at this mid-location the seat cushion 22 and seat frame 12 are located between the first and second support members 26,28. Movement of the connecting apparatus in unison is maintained by the tie apparatus 66 so that the attitude of the seat cushion 22 and seat frame 12 remains constant relative to the support frame 14 throughout the range of movement of the seat frame 12.
Due to the large range of occupant's weight possible the adjustable connecting apparatus 88 is provided to vary the range and therefor accommodate substantially all weights. To adjust the suspended seat assembly 10, to a mid-location, for a given operator weight the operator must rotate the handle 96 in either a clockwise direction to increase the spring tension or in a counterclockwise direction to decrease the spring tension while seated on the seat cushion 22. It is desirable to have the seat in the mid-location when occupied and under static vehicle conditions so that the seat suspension is not too stiff or soft. Under dynamic conditions of vehicle operation, the seat assembly 10 being at the mid-location allows movement up and down and thereby dampens shock and isolates the operator from vehicle motion. It is to be noted that the amount of movement of the seat frame 12 is kept to a minimum, due to the geometry, size, location, and interconnection of the connecting apparatus 42, tie apparatus 66 and biasing arrangement 74.
The gas spring 82 in addition to providing a suspension spring force acts as a shock absorber and dampens the elevational motion of the seat assembly due to its connection with the connecting apparatus 42 and the support frame 14.
Thus, the suspension seat assembly 10 of the subject invention, provides superior suspension characteristics, permits use in vehicle applications wherein overhead clearance is limited due to the ability of the seat frame 12 to move to the second position 40, is compact, has a low profile, is easily adjustable to accommodate different weight ranges and is simple in construction so as to reduce wear and premature failure.
Other aspects, objects and advantages of the invention can be obtained from a study of the drawings, the disclosure and appended claims.
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This invention relates to a suspended seat assembly (10) which eliminates the problems of excessive elevational movement and limited field of use, harsh ride, inability to accommodate a broad range of occupant weights, bulkiness, wear and premature failure, and difficult adjustment. The suspended seat assembly has a seat frame (12), a support frame (14), a connecting apparatus (42) which pivotally connects the seat frame (12) to the support frame (14) and permits movement of the seat frame (12) between a first position (38) above the support frame (14), past the support frame (14), to a second position (40) below the support frame (14), a tie apparatus (66) which maintains the seat frame (12) at a preselected attitude relative to the support frame (14), and a biasing arrangement (74) for biasing the connecting apparatus (42) and urging the seat frame (12) to the first position (38). Thus, the suspended seat assembly (10) useable in vehicle (34) applications wherein low overhead requirements are required, improves ride, accommodates a broad range of occupant weight, is compact, easy to adjust and has improved life. The suspended seat assembly (10) is particularly useful in a material handling vehicle (34).
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BACKGROUND OF THE INVENTION
The present invention relates to distributed computing systems, methods and computer program products, and more particularly, to systems, methods and computer program products for providing web services.
Web services are self-contained, self-describing, modular applications that can be published, located, and invoked across the Web. Web services perform functions that can be anything from simple requests to complicated business processes. Once a web service is deployed, other applications (and other web services) can discover and invoke the deployed service.
Web services may be informational or transactional, i.e., some services provide information of interest to the requestor while other services may actually lead to the invocation of business processes. Examples of publicly available web services today include stock quote services, services to retrieve news from web news sources, and currency conversion services.
Web services are typically deployed on the web by service providers. Service brokers may act as clearinghouses for services. Service brokers may act as matchmakers between service providers and service requestors, by helping service providers and service requesters find each other. Typically, a service requester uses an application programming interface (API) to ask the service broker about the services it needs. When the service broker returns results, the service requestor can use those results to bind to a particular service.
There are three common web services operations. Publishing and unpublishing involve advertising services to a registry (publishing) or removing those entries (unpublishing). The service provider contacts the service broker to publish or unpublish a service. A find operation is performed by service requestors and service brokers together. The service requestors describe the kinds of services they're looking for, and the service brokers deliver results that best match the request. A bind operation takes place between the service requester and the service provider. The two parties negotiate as appropriate so the requestor can access and invoke services of the provider.
Web services may be based on the eXtensible Markup Language (XML) standard data format and data exchange mechanisms, which provide both flexibility and platform independence. With web services, requesters typically do not need to know about the underlying implementation of web services, making it easy to integrate heterogeneous business processes.
Often, services are described by WSDL (Web Service Description Language) WSDL documents that are stored at web nodes. A WSDL document may be stored in numerous ways, such as in a file, in a DB2 XML Registry/Repository (such as the DB2 XRR(XML Registry/Repository)), or in a DB2 based UDDI Registry. UDDI (Universal Description, Discovery, Integration) is a protocol for describing web services such that interested parties may easily discover them. Specifications for this registry and use of WSDL in the registry are available currently at www.uddi.org/. Service providers may register their services in a UDDI, specifying technical information about how to invoke the service.
The discovery and organization of services is typically a manual process, i.e., the burden is typically on the service requesters to locate, organize, and manage multiple contractual relationships. FIG. 1 depicts a conventional environment where service requesters SR 1 , SR 2 develop individual usage contracts to consume specific services S 1 , S 2 , . . . Sj, and a service Sk through which services Sk 1 , Sk 2 , . . . Skm are provided. In such an environment, everything, i.e., the service instances, contracts, and bindings, etc., is specifically identified up front regardless of the scope of services.
A potential limitation of this approach is its static nature, which can reduce the flexibility that is generally desired for e-business application. For example, in such a conventional environment, a new service typically cannot be utilized until it has gone through the full publication process, and requesters have re-subscribed contracts and regenerated their stub codes.
Recently, flexible approaches have been developed based on the concept of a “service grid,” wherein multiple instances of similar capability in nature can be grouped as one service representation. Service grid approaches are generally described in a series of articles “Business Service Grid, Part 1: Introduction,” “Business Service Grid, Part 2: Implementing a Business Service Grid”, and “Business Service Grid, Part 3: Setting Up Rules,” published in February and April of 2003 by IBM on the World Wide Web at www.106.ibm.com/developerworks/ibm/library/i-servicegrid/, www.106.ibm.com/developerworks/ibm/library/i-servicegrid2/, and www.106.ibm.com/developerworks/ibm/library/i-servicegrid3/, respectively. U.S. patent application Ser. No. 10/298,962, entitled “System, Method and Program Product for Operating a Grid of Service Providers Based on a Service Policy,” filed Nov. 18, 2002, also describes other service domain concepts.
SUMMARY OF THE INVENTION
Embodiments of the present invention can provide a transparent service discovery and self-adjusting contracting process that can relieve a service aggregation e.g.(, a Service Domain) of a need to maintain a central repository for every service instance served up from the aggregation. Requestors may also be relieved from the need to enter specific individual contracts for using particular service instances. In some embodiments of the invention, service providers and requestors enter “soft” contractual relationships that can provide increased service discovery and realignment flexibility. Embodiments of the present invention can include the use contracts with providers that are defined in terms of service categories, adjustable contracts with users that are defined in terms of service levels, automatic service discovery, service information topology arrangement, and a polling mechanism to assemble a current service view for requesters on-demand.
In particular, in some embodiments of the present invention, web services may be provided by creating an electronic record of a contract for a service provider to provide web services meeting a web service category definition at a web services hub of a service domain, and providing a web service to a service requestor from the service domain responsive to the electronic record of the contract. The web service may be provided to the service requester without requiring the service requestor to discover a service instance that provides the service. The web service may also be provided without requiring creation of a contract for the use of a specific service instance.
According to some embodiments of the present invention, providing a web service comprises identifying a plurality of ports operative to provide web services meeting the service category definition at the web service hub, and providing the web service to the service requestor responsive to identification of the ports. For example, a plurality of ports may be identified by polling at least one web services node subordinate to the web services hub to identify at least one service provided by the node, and updating a description of a service category, e.g., a WSDL document, responsive to the polling. In some embodiments, a plurality of levels of web services nodes may be polled using a coordinated polling interval scheme to create an updated service view for the service hub.
In further embodiments of the present invention, an electronic record of a second contract to provide web services that meet a service level criterion to the service requester may be created at the web services hub. A web service may be provided to the service requestor responsive to the electronic records of the first and second contracts. For example, a service request from the service requester may be dispatched in the service domain based on the electronic records of the first and second contracts and a service policy of the web services hub.
The present invention may be embodied as methods, systems (apparatus) and computer program products.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating a conventional web services environment.
FIG. 2 is a schematic diagram illustrating soft contracting relationships of service providers and service requesters operative via a service hub aggregation site according to some embodiments of the present invention.
FIG. 3 is a flowchart illustrating exemplary operations for a synchronized service definition polling process according to some embodiments of the present invention.
FIG. 4 is a schematic diagram illustrating exemplary soft contracting relationships in a web services environment using service level definitions according to further embodiments of the present invention.
DETAILED DESCRIPTION
Specific exemplary embodiments of the invention now will be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, like numbers refer to like elements. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present.
The present invention may be embodied as apparatus (systems), methods, and/or articles of manufacture, including computer program products. Accordingly, the present invention may be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.). Furthermore, the present invention may take the form of a computer program product on a computer-usable or computer-readable storage medium having computer-usable or computer-readable program code embodied in the medium for use by or in connection with an instruction execution system. In the context of this document, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
The computer-usable or computer-readable medium may be, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber and a portable compact disc read-only memory (CD-ROM). Note that the computer-usable or computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.
The present invention is described herein with reference to flowchart and/or block diagram illustrations of methods, systems, computer data signals and computer program products in accordance with exemplary embodiments of the invention. It will be understood that each block of the flowchart and/or block diagram illustrations, and combinations of blocks in the flowchart and/or block diagram illustrations, may be implemented by computer program instructions and/or hardware operations. These computer program instructions may be provided to a processor of a general purpose computer, a special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer usable or computer-readable memory that may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer usable or computer-readable memory produce an article of manufacture including instructions that implement the function specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart and/or block diagram block or blocks.
FIG. 2 depicts an overview of an exemplary web services environment according to some embodiments of the present invention. Individual service instances S 1 , S 2 , . . ., Sj, . . . Sk (in individual domains D 1 , D 2 , D 3 and a service domain SCx representing an aggregation of service instances SC 1 , SC 2 , . . . SCm) are aggregated into a main domain D, and represented at a service hub 210 by a list of aggregated service ports. The service hub 210 maintains adjustable usage contracts 212 that specify a service level to which service requester SR 1 , SR 2 are subscribed. On the service provider side, the service hub 210 maintains categorical contracts 214 for the “supplying” domain D to sign up to categories of service, but not specific services.
In some embodiments of the present invention, the service hub 210 may use a periodic polling mechanism to create an overall service view (e.g., database) of the main domain D based on categorical supplier contracts. Because of the categorical nature of the provider contracts, the service view may change over time, as services are added or deleted. For example, a service requestor that requests a service under a “finance” service category can select a variety of services currently available under that category based on the current service view. There is no need to predefine all the services to the service hub 210 in its own repository, as might be done in the prior art.
FIG. 3 illustrates exemplary operations according to some embodiments of the present invention for creating a service view at a service hub using a coordinated polling interval scheme through a domain complex, e.g., using relative polling delays (staggered polling intervals) between levels. In a hub polling loop 310 , polling attributes (e.g., a polling interval or other criterion for initiating a polling process) are set (Block 312 ). When the hub determines that a polling time has arrived (Block 314 ), it retrieves WSDL descriptions of subordinate nodes of its service domain, which are supplied by subordinate domain polling loops 320 (Block 316 ). The hub then updates its WSDL description of the service domain (its service view) (Block 318 ). As shown, in a lower level polling loop 320 for a node subordinate to the service hub, a similar process is carried out, including the setting of polling attributes (Block 320 ), determination of a polling time (Block 324 ), retrieval of WSDLs of subnodes (Block 326 ) and updating of the node's WSDL (Block 328 ). It will be appreciated that WDSL represents a way to describe service information for the various nodes.
A topological relationship protocol such as levels and scopes could be used to further qualify the aggregation behavior. Therefore, when the service hub polls its member domains, it can automatically find out what ports are available to provide services. Later, when a request is received by the service hub, a recursive dispatching process can automatically pick up the best service instance by going through this topology.
To deal with the dynamic nature of the services to both requestor and service providers, a service hub may use a service view database (or other component) to provide query support. Optionally, a service hub may provide properties files to de-couple a user front-end user interface (UI) application from the service hub application functionality (e.g., polling, discovery, topology navigation, etc.) A UI transformation component could be used to further generate UIs dynamically according to user service levels.
FIG. 4 illustrates exemplary contractual relationships that a service hub 410 may maintain with service providers and service requesters, in terms of service lavel definitions 412 , 414 that are mapped to one another according to a service policy 416 . The service definitions 412 , 414 may be viewed as providing adjustable service contracts to a user group 420 and provider contracts to provide a category of services by a service domain 430 . Neither side is bound by the inflexibility of fixed contracts, and both can enter the relationships with the service hub 410 with some fixed services and some classes of services.
For the environment shown in FIG. 4 , an exemplary service level definition for the user side might be (note that XML delimiters “<” and “>” have been removed such that the text displayed below is not executable):
service_levels-section type=“USER” servicelevel name=“GOLD” feebase=“feebase1” qos=“BEST” category name=“baseshopping” port name=“default port” qos=“BETTER” operation name=“getAddress” operation name=“purchaseOrder” operation name=“*” /port category name=“finance” port name=“*” / category ........ . . . . . . . . . . . /servicelevel /service_levels-section
An exemplary service level definition for the provide side might be:
service_levels-section type=“SUPPLIER”
servicelevel name=“PREMIER” feebase=“feebaseA”
qos=“Catagory5”
category name=“baseshopping”
port name=“default port”/
operation name=“getQuoteMultiple”/
operation name=“getQuoteDescriptive”/
operation name=“getAddress”/
operation name=“purchaseOrder”/
/port
category name=“finance”
port name=“*” /
category ........
. . . . . . . . . . .
/servicelevel
. . . . . . . . . . . . . . . . . . .
/service_levels-section
The service policy 416 may be viewed as mapping these different definitions upon one another to complete the contracts. On the provider side, services can be added on demand, with the business relationship in terms of payment, quality of service (QoS), service categories, etc., already agreed upon. On the user side, a service requester can subscribe to a service level that guarantees the types of services, fee scheme, and quality levels. The service hub 410 can prepare the specific service ports responsive to the user service level description at actual runtime based on, for example, the polling and discovery process described above. Reliability can be guaranteed by virtue of the predetermined categorical service agreements.
When inserting a level between sub domains and main domain, or aggregating the main domain to a new super main domain, existing contract relationships can remain intact for all services downward in the affected domains. The new domains can assume the contracts of the affected domains, enter new contracts with the main domain, or substitute contracts offered by the predecessors. Individual services can remain intact and can be insensitive sensitive to domain ownership changes. The main domain can automatically adjust its internal topology pointers to find the services to use at runtime as it goes by coordinating discovery cycles at the various levels. Therefore, embodiments of the present invention can set up a distributed business method that provides a continuous operational service environment that is non-disruptive and self configuring to a domain topology that expands and shrinks naturally. Services can be added and consumed immediately without additional contracting processing. Main and sub domains can control through policies filtering what services to include in the ultimate domain. Services can be added on demand based on market requirements without recompile or rebuild needed from the requesters for using these services.
In the drawings and specification, there have been disclosed exemplary embodiments of the invention. Although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined by the following claims.
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Web services may be provided by creating an electronic record of a contract for a service provider to provide web services meeting a web service category definition at a web services hub of a service domain, and providing a web service to a service requestor from the service domain responsive to the electronic record of the contract. A plurality of ports operative to provide web services meeting the service category definition may be identified at the web service hub, and the web service may be provided to the service requester responsive to identification of the ports. For example, a plurality of ports may be identified by polling at least one web services node subordinate to the web services hub to identify at least one service provided by the node, and updating a description of a service category, e.g., a WSDL document, responsive to the polling. A plurality of levels of web services nodes may be polled using a coordinated polling interval scheme to create an updated service view for the service hub.
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FIELD OF THE INVENTION
[0001] This invention relates generally to the application of a surface coating to a glass display screen of a video display device and is particularly directed to the deposit of a 2-layer antistatic/antireflective coating on the display screen of a video display device such as a color cathode ray tube by means of sputtering.
BACKGROUND OF THE INVENTION
[0002] The outer surface of a display screen, or panel, of a video display device such as a cathode ray tube (CRT) is typically provided with a multi-layer coating which performs various functions. These functions include reducing light transmission through the glass display screen/outer coating combination for improved video image contrast. In addition, an inner layer of the surface coating is electrically conductive in order to shield viewers of the video display device from low frequency electromagnetic radiation and to dissipate electrostatic charge on the display panel to neutral ground. The coating also typically provides an antireflective capability to reduce light reflection from the display screen for ease in viewing a video image on the display screen.
[0003] Various approaches are employed in applying the multi-layer coating to the outer surface of a display screen. These techniques include spin coating, sometimes referred to as the wet method, vacuum vapor deposition, and sputtering. The spin coating method has been widely used with materials containing Ag—Pd or Ag—Au colloid. While the coating thus formed possesses good electrical conductivity and relatively low light reflectance, it is of relatively low quality and involves high processing costs. The spin coating approach also suffers from problems with reproducibility and control of the thickness of the coating. The vacuum vapor deposition approach involves high temperature heat treatment and is thus energy intensive and more expensive than the spin coating approach. The sputtering approach has encountered difficulties in forming at high speed a stable SiO 2 layer having a low refractive index for use in the antireflection layer. One approach for applying a light absorptive antireflective layer to a CRT display screen is disclosed in U.S. Pat. No. 5,691,044. This sputtering approach applies an inner layer of TiN to the surface of a glass substrate. The TiN layer suffers from instability at the high temperatures used for applying the multi-layer coating to the glass substrate. To improve the heat resistance of the TiN layer, an oxide barrier layer of metal nitride (TiN) is formed on the inner TiN layer. This approach requires various reacting gases such as N 2 and O 2 in the sputtering process which increases the cost and complexity of video display screen manufacture.
[0004] The present invention avoids the limitations of the prior art by providing a multilayer antistatic/antireflective coating applied by sputtering to the outer surface of a video display screen which allows for precise control over the thickness of the multilayer coating as well as its light transmission characteristics.
OBJECTS AND SUMMARY OF THE INVENTION
[0005] Accordingly, it is an object of the present invention to provide a multi-layer antistatic/antireflective coating for a video display screen wherein the thickness of the coating may be precisely controlled for precise adjustment of the light transmitted through the coating.
[0006] It is another object of the present invention to provide an antistatic/antireflective coating for the outer surface of a video display panel having precisely controlled conductivity as low as on the order of 103 ohms and reflectivity as low as 0.7%.
[0007] The further object of the present invention is to provide an antistatic coating for the outer surface of a video display panel having a metallic composition and low conductivity, i.e., as low as 10 3 ohms.
[0008] A still further object of the present invention is to provide a multi-layer antistatic/antireflective coating for a video display screen and a method of application therefor, which is metal-based and does not require the use of a reacting gas in producing and depositing the coating by sputtering.
[0009] Yet another object of the present invention is to provide a sputter coating technique for depositing a multi-layer coating on the surface of a video display screen which eliminates the need for a reactive gas and allows for close control of coating conductivity and reflectance by precise control of coating thickness.
[0010] The present invention contemplates a process for forming an antistatic/antireflective coating on an outer surface of a video display screen comprising the steps of: sputter-depositing on the outer surface of the video display screen an inner metallic antistatic layer having a precisely controlled thickness within a range of 2-8 nm, wherein a light refractive index of the inner antistatic layer is also precisely controlled within a range of 2.0-2.8; and sputter-depositing on the inner antistatic layer an outer antireflective layer having a precisely controlled thickness within a range of 70-100 nm, wherein a light refractive index of the outer antireflective layer is also precisely controlled within a range of 1.3-1.47. This invention also contemplates a multi-layer coating for a video display panel having the aforementioned composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The appended claims set forth those novel features which characterize the invention. However, the invention itself, as well as further objects and advantages thereof, will best be understood by reference to the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings, where like reference characters identify like elements throughout the various figures, in which:
[0012] [0012]FIG. 1 is a longitudinal sectional view of a CRT incorporating an antireflective/antistatic coating in accordance with the principles of the present invention;
[0013] [0013]FIG. 2 is a partial sectional view of a flat display screen having an outer surface coating comprised of an inner antistatic layer and an outer antireflective layer in accordance with the present invention; and
[0014] [0014]FIG. 3 is a simplified combined schematic and block diagram of apparatus for applying a multi-layer antireflective/antistatic coating on the outer surface of a video display screen by sputtering in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Referring to FIG. 1, there is shown a longitudinal sectional view of a color CRT 10 incorporating an antistatic/antireflective coating 32 applied by sputtering in accordance with the present invention. In the following discussion the terms “display screen”, “display panel” and “faceplate” are used interchangeably. In addition, the terms “layer” and “coating” are used synonymously. CRT 10 includes a sealed glass envelope 12 having a forward faceplate or display screen 14 , an aft neck portion 18 , and an intermediate funnel portion 16 . Disposed on the inner surface of glass display screen 14 is a phosphor screen 24 which includes plural discrete phosphor deposits, or elements, which emit light when an electron beam is incident thereon to produce a video image on the display screen. Color CRT 10 includes three electron beams 22 directed onto and focused upon the CRT's glass display screen 14 . Disposed in the neck portion 18 of the CRT's glass envelope 12 are plural electron guns 20 typically arranged in an inline array for directing the electron beams 22 onto the phosphor screen 24 . The electron beams 22 are deflected vertically and horizontally in unison across the phosphor screen 24 by a magnetic deflection yoke which is not shown in the figure for simplicity. Disposed in a spaced manner from phosphor screen 24 is a shadow mask 26 having a plurality of spaced electron beam passing apertures 26 a and a skirt portion 28 around the periphery thereof. The shadow mask skirt portion 28 is securely attached to a shadow mask mounting fixture 30 around the periphery of the shadow mask. The shadow mask mounting fixture 30 is attached to an inner surface of the CRT's glass envelope 12 and may include conventional attachment and positioning structures such as a mask attachment frame and a mounting spring which also are not shown in the figure for simplicity. The shadow mask mounting fixture 30 may be attached to the inner surface of the CRT's glass envelope 12 and the shadow mask 26 may be attached to the mounting fixture by conventional means such as weldments or a glass-based frit.
[0016] Referring to FIG. 2, there is shown a partial sectional view of a portion of the CRT's glass display screen 14 having the aforementioned phosphor layer 24 on the inner surface thereof and an outer antistatic/antireflective coating 32 on the outer surface thereof in accordance with the present invention. The glass display screen 14 of FIG. 2 is shown as being flat as the present invention is applicable with both curved display screens as shown in FIG. 1 as well as to flat display screens as shown in FIG. 2. In addition, while the present invention has been illustrated in the figures in terms of use of the outer surface of the display screen of a CRT, the present invention is not limited to use with this type of display device. For example, the antistatic/antireflective coating 32 of the present invention may be used equally as well on the outer surface of the display panel of virtually any type of self-emitting color display device, i.e., where the video image is produced by phosphor activated by energetic electrons incident thereon. Self-emitting color display devices other than CRTs include field emission displays, plasma discharge panels, vacuum fluorescent screens, and gas discharge screens. The phosphor layer 24 disposed on the inner surface of the glass display screen 14 may be in the form of a large number of discrete dots or stripes.
[0017] In accordance with the present invention, the antistatic/antireflective coating 32 includes an inner antistatic layer 46 and an outer antireflective layer 48 . A conductor 50 may be attached to the inner antistatic layer 46 or to the outer surface portion of the display screen 14 for electrically coupling the display screen to neutral ground potential. In this manner, the build up of electrostatic charge on the display screen 14 is limited by discharging the electrostatic charge on the display screen to neutral ground via the electrically conductive inner antistatic layer 46 .
[0018] Shown in FIG. 3 is a simplified combined schematic and block diagram of a sputter deposition apparatus 60 for applying an antistatic/antireflective coating to the outer surface of the glass display screen 62 a of a CRT 62 in accordance with one aspect of the present invention. Sputter deposition apparatus 60 includes a dual chamber 64 comprised of a larger chamber 64 a and a smaller chamber 64 b which are connected together by means of a valve 65 . A conventional sputtering system (not shown for simplicity) is disposed within the vacuum chamber 64 for sputtering targets onto the outer surface of the display screen 62 a of CRT 62 . Each of the larger chamber 64 a and the smaller chamber 64 b has its own vacuum gauge and valve for controlling the respective pressures therein. Thus, the larger vacuum chamber 64 a is provided with vacuum gauges 70 , 74 , and 84 for monitoring the pressure therein. A discharge valve 72 allows for air to enter the larger chamber 64 a such as for performing maintenance on the larger chamber. Vacuum gauge 66 permits monitoring of the pressure in the smaller vacuum chamber 64 b , while a discharge valve 68 allows for the entry of air into the smaller chamber for inserting or removing the display screen 62 a of CRT 62 . A diffusion pump 76 is connected to the combination of the larger chamber 64 a and smaller chamber 64 b via a gate 78 . Vacuum gauges 80 and 82 are also connected between the diffusion pump 76 and the combination of the larger chamber 64 a and smaller chamber 64 b for monitoring the vacuum level within the diffusion pump. A pair of mechanical pumps 86 and 88 are connected to the diffusion pump 76 by means of respective valves 98 and 100 . A vacuum gauge 94 is also connected between the mechanical pumps 86 , 88 and the diffusion pump 76 for monitoring the pressure of the vacuum pumps. The combination of a pair of mechanical pumps 90 and 92 is coupled to the larger chamber 64 a and the smaller chamber 64 b by means of respective valves 108 and 106 . In addition, mechanical pumps 90 and 92 are coupled to the valves 106 and 108 by means of valves 102 and 104 , respectively, as well as by means of a vacuum gauge 96 . Vacuum gauge 96 allows for monitoring the pressure of the vacuum pumps 90 and 92 .
[0019] The sputter deposition apparatus 60 operates in the following manner. Machanical pumps 86 and 88 are turned on for pumping the diffusion pump 76 with valves 98 and 100 in the open position. Mechanical pumps 90 and 92 are turned on for pumping the larger vacuum chamber 64 a with valves 102 , 104 and 108 all in the open position. Valves 98 , 100 , 102 and 104 are always open. When the pressure of the diffusion pump 76 and the pressure in the larger vacuum chamber 64 a reach the working pressure, gate 78 opens and valve 108 closes. The display screen 62 a of CRT 62 is then loaded in the smaller vacuum chamber 64 b and valve 106 opens for pumping the smaller vacuum chamber down to the working pressure by means of mechanical pumps 90 and 92 . When the pressure within the smaller vacuum chamber 64 b reaches the working pressure, valve 65 disposed between the larger and smaller vacuum chambers 64 a, 64 b opens to equalize the pressure between the two chambers. The sputtering system within the smaller vacuum chamber 64 b then deposits the sputtering targets onto the outer surface of the CRT's display screen 62 a . After coating the outer surface of the CRT's display screen 62 a with the multi-layer antistatic/antireflective coating of the present invention, valve 65 closes and valve 68 opens for allowing air into the smaller vacuum chamber 64 b . The CRT 62 is then unloaded, or removed, from the smaller vacuum chamber 64 b and another CRT is loaded in the smaller vacuum chamber. The above described sequence of steps is then repeated for the new CRT now loaded in the small vacuum chamber 64 b.
[0020] The sputter deposition apparatus 60 of FIG. 3 permits the thickness of the inner antistatic layer 46 to be controlled with great precision. The thickness of the inner antistatic layer 46 may be controlled to within 2-8 nm. The inner antistatic layer 46 preferably includes the metals Ti or Cr. By precisely controlling the thickness of the inner antistatic layer 46 , its light refractive index may be controlled to be within the range of 2.0-2.8. The inner antistatic layer 46 is preferably provided with a low conductivity such as on the order of 103 ohms and a low reflectance on the order of 0.7%. The outer antireflective layer 48 preferably includes SiO 2 or MgO. The thickness of the outer antireflective layer 48 may also be precisely controlled so as to be within a range of 70-100 nm. By thus controlling the thickness of the outer antireflective layer 48 , its light refractive index may be precisely controlled to be within the range of 1.3-1.47.
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A two-layer antistatic/antireflective coating technique employs a 2-step sputtering approach for first depositing an inner metallic antistatic layer on the outer surface of a glass display screen of a video display device such as a cathode ray tube (CRT), followed by deposit of an outer antireflective layer on the antistatic layer. The inner metallic antistatic layer is comprised of Ti and Cr and has a light refractive index of 2.0-2.8 and a thickness of 2-8 nm. The outer antireflective layer is comprised of SiO 2 and MgO and has a light refractive index of 1.3-1.47 and a thickness of 70-100 nm. Light transmission through the inner metallic antistatic layer may be closely adjusted as desired by precise control of the thickness of this inner layer.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional patent application Ser. No. 60/834,033 filed Jul. 28, 2206
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to article covers such as tablecloths and, more particularly, relates to a self-adhering article cover. The invention additionally relates to methods of making and using such an article cover.
[0004] 2. Discussion of the Related Art
[0005] Tablecloths and other article covers are often used both indoors and outdoors to protect articles from spills and/or to prevent items such as food from being contaminated by the articles. In the case of tables such as picnic tables, the article cover typically takes the form of a reusable cover made of cloth or plastic or a disposable cover made of paper, plastic, or a nonwoven material.
[0006] Tablecloths and other article covers typically are simply laid on the article and held in place by their own weight, friction, and the weight of items placed on the article cover. The resulting limited retention forces can be insufficient to hold the cover in place on windy days, in which case the wind lifts the cover at least partially off the article, potentially spilling items on the cover.
[0007] Proposals have been made to alleviate this problem through the provision of a tablecloth having adhesive strips on the underside of the tablecloth at strategic locations such as the corners of the tablecloth. See, for example, U.S. Pat. No. 6,578,499 to Kroll. However, these tablecloths are expensive to manufacture. They also cannot be wound onto rolls and, therefore, are relatively cumbersome to package and handle and expensive to store and ship. They are also only partially effective because the adhesive is applied to only portions of the tablecloth, leaving large portions of the cover free to move relative to the article. For example, the tablecloth may billow in the middle as wind flows upwardly through gaps between wooden boards or through metal mesh in the table.
[0008] The need therefore has arisen to provide a self-adhering tablecloth or similar article cover that is inexpensive to manufacture, reliable, and easy to use.
[0009] The need additionally has arisen to provide a self-adhering article cover that can be rolled upon itself to facilitate packaging, shipping, storage, handling, and application.
SUMMARY OF THE INVENTION
[0010] In accordance with an aspect of the invention, at least some of the above-identified needs are met by providing a self-adhering tablecloth or similar article cover formed from a flexible material having an adhesive applied to an underside thereof. The cover preferably is formed from an inexpensive, flexible material such as paper, plastic film or a non-woven material. Its upper surface may be plain or decorated such as by printing or lamination. The adhesive preferably is one that provides sufficient tack to retain the cover on the article but that allows relatively low-effort detachment of the cover from the article and clean removal of the adhesive from the article. It also should be releasable from the upper surface of the cover, hence permitting the material of the cover to be wound onto rolls from which multiple covers may be dispensed. The cover may be applied to the article in one piece or as a number of separated or overlapping strips.
[0011] In accordance with other aspects of the invention, methods of making and using the cover are provided.
[0012] These and other features and advantages of the invention will become apparent to those skilled in the art from the following detailed description and the accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings, in which like reference numerals represent like parts throughout, and in which:
[0014] FIG. 1 is a top plan view of a tablecloth constructed in accordance with a preferred embodiment of the invention and showing the tablecloth spread onto a table;
[0015] FIG. 2 is a bottom plan view of the tablecloth of FIG. 1 ;
[0016] FIG. 3 is a sectional end view of a strip of the tablecloth of FIGS. 1 and 2 ;
[0017] FIG. 4 is a perspective view of a rolled web from which the strip of FIG. 3 can be cut, and of a dispenser for the web; and
[0018] FIG. 5 is a schematic view of a system for manufacturing the roll illustrated in FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] A preferred embodiment of the invention will now be described in the form of a tablecloth, it being understood that the invention is also applicable to other self-adhering removable article covers as well.
[0020] Referring initially to FIGS. 1-3 , a tablecloth 10 is illustrated that covers the upper surface of a table 8 such as a picnic table or a patio table. The size and shape of the tablecloth 10 may vary from application to application. It may, for example, take the form of a 4′ diameter round cover or a 3′×6′ rectangular cover. The tablecloth 10 may be formed of a single pre-formed article of dimensions sufficient to cover the table. Alternatively, it could be formed from multiple strips of “standard” width and a user-specified length. The illustrated tablecloth 10 is configured to be used in a multi-strip application in which two or more parallel strips 12 are laid onto to the top of the table 8 , preferably in an overlapping manner, with a seam 14 therebetween.
[0021] Referring to FIG. 3 , each strip 12 of the tablecloth 10 is formed from a substrate 16 having upper and lower surfaces 18 and 20 . An adhesive 22 is applied to the lower surface 20 of the substrate 16 . Depending on the properties of the adhesive 22 , the manner of applying the adhesive to the substrate, and the properties of the substrate 16 , as well as the intended methods of packaging and use, a release coating 24 may also be applied to the upper surface 18 of the substrate 16 .
[0022] Still referring to FIG. 3 , the substrate 16 may be formed from any material capable of receiving the adhesive 22 on its bottom surface 20 . It also preferably is sufficiently flexible to be wound onto a roll, unwound from the roll, and laid flat on a table with minimal effort. It should also be disposable. The substrate 16 may, for instance, comprise paper or a film formed from a polyolefin film such as polyester or polypropylene. It could also be formed from a nonwoven material such as a melt blown, spunbond, or needle punched material. The substrate 16 should be sufficiently thin to be windable on roll yet sufficiently thick to be durable. Depending on the characteristics of the material and on the application, a thickness of 0.5 mil. to 10 mil. is preferred, and a thickness of about 1.5 mil. to 2.5 mil. is especially preferred.
[0023] The upper surface 18 of the substrate 16 may be plain or may be decorated in any desired manner such as a pattern 19 ( FIG. 1 ). Decoration may be applied, for example, by direct printing or silk screening. The decoration could also be applied by reverse printing and lamination to provide scuff resistance. As still another alternative, the material of the substrate 16 may itself can be pigmented in any of a variety of colors or patterns. Additionally, a decorated or undecorated nonwoven layer may be laminated to the upper surface 18 of a film substrate to impart a cloth-like feel to the tablecloth 10 .
[0024] The adhesive 22 should be sufficiently tacky to hold the tablecloth 20 to typical table surfaces such as wood, glass, plastic, stone, or metal. However, it should not be so tacky that the tablecloth 10 cannot be easily removed from the table 8 . It preferably is stronger in sheer than in peel to promote a secure hold to the table 8 while permitting the tablecloth 10 to be easily removed form the table 8 after use by simply peeling the tablecloth 10 from the table 8 . The adhesive 22 also should also be one that minimizes post-removal cleaning of the table. It preferably adheres to the tablecloth 10 with greater strength than to the table so as to leave no residue. Even if some residue remains, the residue preferably is of the type that can be easily removed It should also be non-toxic and, even more preferably, food-grade. A variety of repositional materials similar to those used in the label technology industry are suitable for at least most of these purposes. These materials may be hot-melt or solvent based. For instance, they may be rubber based, Kraton® based, acrylic, SIS, SBS, or another block co-polymer.
[0025] The adhesive 22 should cover a sufficient portion of the lower surface 20 of the substrate 16 to assure that the entire tablecloth 10 adheres to the table 8 . A continuous layer is, of course, ideal for this purpose, but may not be practical from an expense standpoint and may be difficult to remove from the tabletop after use. Therefore a discontinuous coating that covers a substantial portion of the surface area of the tablecloth 10 is preferred. Such coatings may, for example, be applied by spray coating, starved die, random fiberization, oriented fiberization, or other non-contact applications. These coatings may also be applied by contact methods such as roll, gravure, or print coating.
[0026] In the preferred embodiment in which the tablecloth 10 is wound onto a roll, release coating 24 preferably is applied to the upper surface 18 of the substrate 16 to prevent the web 30 (detailed below) from which the strips 12 of the tablecloth 10 are cut from sticking to itself when the web 30 is wound onto the roll. The release coating may, for example, comprise a silicone-based coating, a UV cured coating, a cross-linked coating, any of a variety of coatings used for label applications.
[0027] Referring to FIG. 4 , the strips 12 are preferably cuttable from a web 30 wound onto a roll 32 . The roll 32 is mounted in a dispenser 34 covered by a lid 36 and bearing a cutting device such as a cutting edge 38 . The web 30 is wound onto itself with the adhesive 22 on the bottom surface and the release coating 24 on its upper surface. The web 30 can be unwound from the roll 32 , cut to a desired length using cutting edge 38 to form a strip 12 , and as many strips as are needed can then be pressed onto the table 8 to form the tablecloth 10 . The adhesive 22 retains the tablecloth 10 on the table 8 during use by sticking to at least a substantial portion of the table's surface. After use, the tablecloth 10 can be peeled off the table 8 and disposed of. It can even be wrapped around trash on the table and used as a trash bag.
[0028] Referring to FIG. 5 , a system 40 is illustrated that applies adhesive and a release coating to a web 30 ′ of the substrate to form the web 30 as described above in conjunction with FIG. 4 . Reference characters from FIGS. 1-4 , while not shown in FIG. 5 , will also be referred to in order to facilitate an understanding of the relationship between the web 30 ′, the web 30 , and the strips 12 . The major components of system 40 include an unwind station 42 , a release coating station 44 , an adhesive application station 46 , and a rewind station 48 .
[0029] Still referring to FIG. 5 , the unwind station 42 supports a roll 50 of substrate 16 from which the web 30 ′ is withdrawn under tension from the rewind station 48 and/or driven nip (not shown) and fed downstream through the system 40 with the upper surface 18 of the substrate 16 facing downward. (It should be noted that the upper surface 18 of the substrate 16 could face upward, in which case the release coating station 44 and related equipment would be located above the web 30 ′ and the adhesive application station 46 would be located beneath the web 30 ′) The upper surface 18 may be pre-decorated on its upper surface as described above. Alternatively, a decorating station (not shown) could be provided between the unwind station 42 and the release coating station 44 .
[0030] With continued reference to FIG. 5 , the release coating station 44 applies the release coating 20 to the downwardly facing upper surface 18 of the substrate 16 . Release coating station 44 may comprise a basin 52 that stores a liquid release coating material and nip rollers 54 and 56 that draw the web 30 ′ through the release coating station 44 while transferring the release coating material to the web 30 ′. The release coating may be cured with a UV curing device 58 located downstream from the release coating station 44 in the direction of web movement. The adhesive application station 46 applies adhesive 22 to the bottom surface 24 of the substrate 16 . The adhesive 22 may be applied by contact using a slot nozzle, rollers or the like or without contact by, for example, melt blowing or a Controlled Fiberization® spray application or any number of airless or air-assisted spray methods.
[0031] In the typical case in which the finished rolls 32 are less than 2′ wide and the bulk substrate of the web 30 ′ being unwound from the unwind station 42 is much wider (typically on the order of 6′ to 8′), the web 30 ′ can be slit to the desired widths of webs 30 using slitters 60 spaced along the width of the web 30 ′. The slitters 60 may, for example, comprise rollers or knives. The adjacent webs 30 are then wound on axially aligned rolls 32 in the rewinding station 48 . Instead of or in addition to the slitters 60 , folders may be provided to fold the web in a V-fold or C-fold. This feature would provide the advantage of providing a tablecloth that is wider than the axial length of the roll 32 , negating the need to apply the tablecloth 10 in multiple strips 12 . In this case, a release liner should be applied to the web 30 ′ downstream from the adhesive application station 46 to prevent the facing adhesive-bearing surfaces of the folded web from sticking to each other.
[0032] Although the best mode contemplated by the inventors of carrying out the present invention is disclosed above, practice of the present invention is not limited thereto. It will be manifest that various additions, modifications and rearrangements of the features of the present invention may be made without deviating from the spirit and scope of the underlying inventive concept. Some of the changes are discussed above. The scope of still other changes to the described embodiments that fall within the present invention but that are not specifically discussed above will become apparent from the appended claims.
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A self-adhering tablecloth or similar article cover is formed from a flexible material having an adhesive applied to an underside thereof. The cover preferably is formed from an inexpensive, flexible material such as paper, plastic film or a non-woven material. Its upper surface may be plain or decorated such as by printing or lamination. The adhesive preferably is one that provides sufficient tack to retain the cover on the article but that allows relatively low-effort detachment of the cover from the article and clean removal of the adhesive from the article. It also should be releasable from the upper surface of the cover, hence permitting the cover material to be wound onto rolls. The cover may be applied to the article in one piece or as a number of separated or overlapping strips.
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FIELD OF THE INVENTION
This invention relates to couplings for high pressure hose lines. In particular it relates to a hose coupling that will automatically disconnect when a predetermined level of tension is applied to the connector by pulling on the hose line. More particularly, the invention can be adapted to a coupling with an automatic shut-off feature, as where the line or hose being coupled carries a fluid, such as gas, hydraulic oil or steam under pressure and is provided with a check-valve to close off the line upon disconnection.
BACKGROUND TO THE INVENTION
In the handling of high pressure fluids it is known to provide hose connectors that include an internal shut-off or check valve. The check valve closes automatically on decoupling of the connector in order to prevent the leakage of gas or liquid from the disconnected coupling. Auto-shut off connectors are useful as well on high pressure air lines to prevent such lines from thrashing when disconnected.
Examples of patents that have issued for this class of connector includes U.S. Pat. No. 4,865,077 to Batchen, and U.S. Pat. No. 4,827,977 to Fink and Husky. Various commercial models previously in use include the HANSEN Coupling made by the Hansen Coupling Division of Tuthill Corporation of Cleveland, Ohio, TOMCO connectors by Tomco Division of C.S.P. Inc. of Willowick, Ohio and HOFMANN connectors by Hofmann Engineering Co. Inc. of Burr Ridge Ill.
In the Hansen design, which is typical, a male portion of the connector, called hereafter the "plug", is held in place within a female portion of the connector, called the "female coupling", by radially located steel balls. These balls are contained in a race around the inner circumference of the female coupling. The steel balls partially inter-fit into a complementary groove formed on the outer circumference of the plug, once the connector portions are assembled. The steel balls are radially displaceable within their race, but are held in an advanced, groove-engaging, locking position by an outer locking/release ring.
This outer ring is displaceable longitudinally, and carries an inner groove into which the steel balls may be displaced, once this groove is aligned with such balls. Adjacent the groove, an inner locking surface on the ring holds the balls in their advanced, locking position within the race when advanced to overlie the balls.
The locking/release ring is biased by a spring to advance along the connector until the locking surface overlies the steel balls. By overcoming this bias, i.e. by displacing the locking/release ring, the groove may be aligned with the steel balls to effect engagement and disengagement of the coupler portions.
The Hansen coupling requires manipulation to effect engagement of the coupling. That is, the locking/release ring must be displaced manually to allow the steel balls to recede within their race while coupling is effected. Other connectors provide for automatic engagement upon insertion of the plug into the female coupling.
In the field, connectors of the Hansen type have been rendered into auto-disengaging couplings that disconnect under tension developed by pulling on the line leading to the connector. This has been effected by anchoring the release ring to a stationary object by a linkage, such as a chain. Tension on the line causes the connector to move with respect to the release ring. Upon sufficient displacement of the connector with respect to the release ring, release is effected.
In the Hansen connector, the steel balls, which serve as a latch means, are continually subject to a pressure, arising from the tendency of the connector portions to separate. This pressure, if it were not for the presence of the locking/release ring in its appropriate position, would displace the steel balls and effect release of the coupling.
The Hansen-type coupling is relatively insensitive to line pressure as the thrust on the steel balls is partially absorbed by the race, and the frictional resistance between the locking/release ring and the steel balls is correspondingly reduced. Nevertheless, some resistance exists, and this residual resistance is proportional to line pressure.
Another type of connector in this field is that manufactured by S. A. Des Etablissements Staubli of France. This device, depicted in European Patent Application 82420113.1 and published as EP-0-077-734-A1, shows a connector wherein a transverse activating pin provides a double latching action for release of the connector. The focus of this patent is on the double latching action.
In both the Hansen and Staubli type connectors a single internal check valve, biased to close by a spring, may be provided. This check valve can be contained within a female portion of the connector, but could alternately or also be located in the male or plug portion. In all cases a probe carried on the opposing portion of the connector, when assembled, holds the check valve open.
The Staubli connector differs from the Hansen connector in that engagement of the connector does not require any manipulation of a locking ring or the like. Instead, engagement is effected by the mere application of insertion pressure on the plug into the female coupling whereby a bayonet-like engagement is effected. The barb-equivalent on the plug portion of the Staubli connector is a ring with a bevelled forward edge and a perpendicular rearward side. This rearward side engages with and is held in place by a first latching portion of the transverse activating pin, once the connector is assembled.
The double latching effect arising on uncoupling in the Staubli connector is achieved by a second latch portion on the activating pin that stops the withdrawal of the male plug portion of the connector after partial disconnection occurs. This interruption of the disengagement process allows the check valve to close and the line carrying the plug, which lacks its own check valve, to depressurize without thrashing. Release of the second latch allows full withdrawal to be effected.
The Staubli connector is manually operated. However, its feature of reliance on a transverse activating pin to effect decoupling can be adapted to provide a tension-activated auto-disengaging connector. Such a tension-activated connector is useful particularly where compressed gas is being pumped into a vehicle holding tank, as where cars are fueled by compressed natural gas. On occasion an operator may decide to move the vehicle, forgetting to manually disconnect the coupling on the fluid feed line. By providing a tension-activated coupler the risks of having a ruptured fluid line are eliminated.
The activating pin in the Staubli connector differs from the locking/release ring in the Hansen type connector in that the Staubli connector requires that pressure be applied to the activating pin or actuator so that unlatching of the connector may be effected. Because the barbed ring on the plug is held by a latch that is displaced transversely, there is no tendency for line pressure to disengage the latch. A positive displacement of the actuator by application of actuating pressure is necessary in order to cause the latch to disengage.
Accordingly, it is an object of this invention to provide a tension-activated auto-disengaging coupler that contains an actuator for the latch that is biased by a spring to resist actuation but contains a means that will automatically effect disengagement when a predetermined tension is applied to the coupling.
The invention is its general form will first be described, and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention will then be further described, and defined, in each of the individual claims which conclude this Specification.
SUMMARY OF THE INVENTION
According to the invention a tension-activated auto-disengaging fluid line connector is provided that comprises:
(1) a connector with complementary, interfitting but disengageable male and female portions, one of such portions being provided with line coupling means for connection to a hose containing a source of high pressure fluid and thereby constituting the pressurized portion of the connector, the other portion of the connector constituting the non-pressurized portion of the connector.
(2) a spring-activated check valve contained within the pressurized portion of the connector, biased by a check valve spring mounted within the said pressurized portion to displace the check valve towards closure;
(3) a probe, forming the non-pressurized portion of the connector for opening the check valve upon assembly of the connector;
(4) latch means for releasably holding the male and female connector portions together, once assembled,
(5) an actuator, connected to said latch means so as to effect release of the latch means by the application of pressure to the actuator, such actuator being accessible from outside of the connector;
(6) a housing, provided with a means for such housing to be anchored externally to a stationary body, such housing extending over the actuator and positioned to contact and apply pressure to activate such actuator upon displacement of the housing with respect to the connector and;
(7) a principal spring means biasing the housing to separate from the actuator;
wherein the housing and actuator are positioned so that upon application of tension to one portion of the connector, the housing will advance towards the actuator, and at a predetermined level of tension, will activate such actuator by applying pressure thereto and thereby and effect release of the latch means and disengagement of the male and female portions of the connector.
In a preferred arrangement of the invention, the actuator is mounted transversely in the connector and is provided with a conically bevelled outer end that contacts with an inner camming surface on the housing, preferably in the form of an annular rim, in order to activate such actuator.
The foregoing summarizes the principal features of the invention. The invention may be further understood by the description of the preferred embodiments, in conjunction with the drawings, which now follow.
SUMMARY OF FIGURES
FIG. 1 is a cross-section of a female coupler;
FIG. 2 is a side view of a male plug with hose attached aligned with the coupler of FIG. 1.
FIG. 3 shows a housing anchored by a chain to a stationary object;
DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1 a female coupling 1 forming part of a connector 2 assembled within a housing 3 is shown. The female coupling 1 has a transversely mounted latch actuator 4 mounted in a transverse bore in the body 5 of the female coupling 1. The actuator 4 is provided with a bevelled external end 6 and a transverse passage 7 to receive a male plug 8 and hose 8a, shown separately in FIG. 2.
The plug 8 carries a barbed engagement ring 9 and a probe 10. The probe 10 presses open the check valve 11 contained in the female coupling 1 overcoming the resistance of the check valve spring 12.
The barbed ring 9 on the plug, when assembled, is locked in place by the latch 13 which is a protruding surface carried on the actuator 4. The actuator 4 is biased by an actuator spring 14 to hold the latch 13 in engagement with the ring 19. Although the actuator 4 is shown as integrally carrying the latch 13, these components may be joined by linkages, allowing the actuator end to protrude in the longitudinal direction from the end of the body 5.
By the application of pressure to the actuator's bevelled end 6, the resistance of the actuator spring 14 may be overcome, and the latch 13 displaced to release the plug 8.
The female coupling 1 is contained within a housing 3 with the access opening 16 for the plug 8 to enter the female coupling 1 accessible through a housing-access opening 17. The female coupling 1 is partially free to slide within the housing access opening 17, such travel being limited by retention-ring 18 and contact between the bevelled end 6 and a circular pressure rim 19 formed on the inside of the housing access opening 17. Displacement of the female coupling 1 towards the rim 19 will create a pressure on the actuator 4 by reason of the angle of the surface 20 formed on the bevelled end 6 of the actuator 4.
The female coupling 1 terminates at the end opposite the access opening 16 with a nippled adaptor 21 that has a protruding nipple 21a and a first central passage 22 for conducting fluid to a hose 28 (shown in FIG. 4). In a basic version of the invention, the nipple 21a connects directly to a hose and the adaptor 21 is retained from removal from the housing 3 by a retention ring 18.
The adaptor 21 has an annular shoulder 23 against which thrusts a principal housing spring 23a. This spring 23a, in turn, thrusts at its opposite end against the housing 3 optionally through a washer 24. The tendency of this principal spring 23 is to move the female coupling 1 and the bevelled end 6 of the actuator 4 away from the pressure rim 19 on the housing 3.
In use the housing 3 is anchored to a stationary object 26, such as a manifold or frame, as by a chain or wire harness 27 as shown in FIG. 4. If the hose 28 is sufficiently sturdy it may also serve to attach the connector housing 3 to a stationary object, so long as sufficient slack is provided to permit the connector to move within the housing.
CONCLUSION
The foregoing has constituted a description of specific embodiments showing how the invention may be applied and put into use. These embodiments are only exemplary. The invention in its broadest, and more specific aspects, is further described and defined in the claims which now follow.
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An in-line connector for a hose is provided with an automatic release mechanism which allows the connector to uncouple when a predetermined level of tension is applied to the connector through the hose.
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BACKGROUND OF THE INVENTION
The invention relates to a socket for a miniature incandescent lamp for the detachable and lockable insertion in a recess in a printed circuit board and for making electrical contact with the lamp by pressing the connecting leads against the printed circuit board with a separate manufacture of the socket and the lamp.
Such a socket is already known from U.S. Pat. No. 4,193,653. For this embodiment, the socket consists of a single part, through which the connecting leads of the lamp are passed. In the lower part of the socket, the leads form a loop in a guide in a flange. When the socket is inserted, the flange presses the connecting leads, which emerge at its upper side, against the underside of the printed circuit board.
This principle of making electrical contact between the connecting leads of the lamp and the printed circuit board has several advantages over constructions with integrated contact elements of metal or a conductive plastic, to which the connecting leads of the lamp are soldered, welded, riveted, wedged, glued, integrally molded or pressed. The socket can be produced in a single operation, because it consists of only a single plastic part. Since the glass bulb is not subjected to stresses either by temperature or by pressure during the insertion of the lamp, the material properties of the glass lamp are of no significance and the socket is suitable for all lamps of appropriate construction.
The manufacture of the socket of U.S. Pat. No. 4,193,653 is uncomplicated. However, the insertion of the lamp in the socket creates considerable difficulties. For this purpose, the lamp with the connecting leads aligned in parallel must first of all be brought into the socket, so that the connecting leads pass through an opening for each in the bottom of the socket. Subsequently, each connecting lead is threaded at least twice more through recesses provided for this purpose in a flange in the base. The fact that the connecting leads of the lamp generally are very thin and are easily bent if they are not introduced without making contact, is particularly disadvantageous. Inserting the lamp in the socket by hand is therefore unreasonable, even in the case of small numbers. It is therefore out of the question to sell the lamp and the socket separately. Instead, the lamp must be offered with the socket as a finished unit. Moreover, the insertion of the lamp in the socket requires complicated, precision and therefore expensive machines.
SUMMARY OF THE INVENTION
It is an object of the invention to design a socket of the initially described type in such a manner, that the insertion of the lamp in the socket and, particularly, the correct guidance of the connecting leads of the lamp does not present a problem and is possible with the simplest of tools and, if necessary, manually. To accomplish this objective, the socket of the initially described type consists pursuant to the invention of a hollow cylinder with two axially superimposed parts of different external diameters. To accommodate the connecting leads of the lamp, the hollow cylinder has two diametrically opposed longitudinal slots, the width of which corresponds approximately to the diameter of the connecting leads and which extend over the whole height of the part of smaller diameter and into the part of larger diameter by an amount corresponding at most to the diameter of the connecting leads. As a consequence of this construction, the lamp with the connecting leads bent outwards can be inserted in the socket. In so doing, the connecting leads are guided in the slots of the socket and limit the insertional movement of the lamp when they come up against the bottom of the longitudinal slots. For this process, the snug fit of the wires in the slots can be taken into account. The unit of socket and lamp is then introduced with the glass bulb in front from the underside of the printed circuit board into the recess of the latter, until the printed circuit board comes up against the connecting leads. During this procedure, the connecting leads form, as it were, a stop, which prevents the further penetration of the socket into the opening of the printed circuit board. The contacting pressure, exerted by the printed circuit board on the connecting leads, produces a reliable electrical contact between the leads and the contact surfaces on the underside an printed circuit board. An additional deformation or a further threading of the ends of the connecting leads becomes unnecessary here.
It is within the scope of the invention that the socket consists of an elastic material and that two radially movable springs are disposed on the part of larger diameter parallel to the axis and offset by 90° to the slots disposed in the socket. With a catch head protruding outwards at their free end, these springs overlap the printed circuit board, pressing on the connecting leads lying in the slots. The catch heads are disposed at a distance from the shoulder of the cylinder of larger diameter. This distance is somewhat smaller than the average thickness of the printed circuit board.
It has also proven to be particularly advantageous that two radial depressions, each of which guides a shaft of the springs, are disposed at the recess of the printed circuit board that accommodates the socket. By these means, twisting of the inserted socket with respect to the printed circuit board is avoided and the connecting leads of the lamp always lie at the same place of the underside of the printed circuit board. The contact surfaces can therefore be limited to a small sector at the periphery of the printed circuit opening, offset by 90° to the radial depressions of the printed circuit board.
It is within the scope of the invention that the springs are disposed in radial recesses of the hollow cylinder and are integrally molded with their foot to the part of larger diameter of the socket. Recesses in the cylinder of lesser diameter in the form of depressions or slots in the region of the springs increase the free spring excursion of the catch heads. These catch heads can be constructed larger, as a result of which the socket is also suitable for printed circuit boards, the thickness of which has a greater tolerance. To extend the spring excursion, the recesses, which accommodate the springs, can extend as far as into the cylinder of larger diameter. The depth of these recesses is limited by the requirement of an adequate stability of the socket.
An alternative embodiment of the invention is distinguished owing to the fact that, at the external periphery of the smaller diameter part of the socket, two clamping heads, which overlap the printed circuit board, are integrally molded directly. The axial distance of these clamping heads from the shoulder of the part of larger diameter corresponds approximately to the thickness of the printed circuit board. The clamping heads reach through appropriate depressions in the printed circuit board and can be locked with respect to this by rotation of the socket. By these means, a type of bayonet catch is formed. It is particularly advantageous not to dispose the clamping heads offset by 90° relative to the slots and to provide a clear direction of rotation for the locking. The slot nearer to a clamping head indicates the direction of rotation for the locking with respect to the clamping head. At the end of at least one clamping head, which is the rear end in the direction of rotation of the locking motion, a stop, which limits the rotational motion, is mounted in order to prevent the connecting leads of the lamp reaching the region of radial depressions of the opening of the printed circuit board, when the angle of twist is too large or when the rotation is in the wrong direction and being bent by the edge of this opening, when the direction of rotation is reversed.
Finally, in a further refinement, the invention provides for notches at the periphery of the part of the socket of larger diameter. These notches extend over the axial length of this part of larger diameter and are connected with the slots for accommodating the bent ends of the connecting leads. By guiding the ends of the connecting leads of the lamp, the danger of a short circuit with adjacent contacts is decreased appreciably. In the case of the socket with the bayonet catch, a bending of the wire during the locking operation can be avoided in this manner. Moreover, the possibility exists of bending the wire in such a manner, that it protrudes partially from the bottom of the slot and so produces a springiness, which supports the electrical contact.
Further characteristics, details and advantages of the invention arise out of the following description of some preferred embodiments of the invention, as well as out of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a miniature incandescent lamp with bent connection leads, before insertion in the socket,
FIG. 2 shows a front view of a first embodiment of the invention after the insertion in a printed circuit board,
FIG. 3 shows a plan view of FIG. 2, without the printed circuit board,
FIG. 4 shows the embodiment of FIG. 2, turned through 90°,
FIG. 5 shows the underside of the associated printed circuit board together with contact surfaces,
FIG. 6 shows a front view of a second embodiment of the invention, together with the inserted lamp,
FIG. 7 shows a plan view of FIG. 6,
FIG. 8 shows the embodiment of FIG. 6, turned through 90° and inserted in a printed circuit board,
FIG. 9 shows the underside of the associated printed circuit board together with the contact surfaces,
FIG. 10 shows a front view of a further embodiment of the invention,
FIG. 11 shows a plan view of FIG. 10, and
FIG. 12 shows the embodiment of FIG. 10, turned through 90° and inserted in a printed circuit board.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment is reproduced in FIGS. 2, 3 and 4. The socket 1 serves to accommodate the miniature incandescent lamp 2 with a cylindrical glass bulb 3, at the bottom of which two lamp connection leads 5 emerge. The points of emergence are approximately diametrically opposed with respect to the longitudinal axis of the glass bulb 3. Before the lamp 2 is inserted in the socket 1, the connecting leads 5 must be bent upwards at a distance from the bottom 4 of the glass bulb 3, which is small in relation to the length of the connecting leads 5, so that they form an angle of about 30° with the longitudinal axis of the glass bulb 3, as shown in FIG. 1. The socket 1 consists of an elastic material and is bounded towards the outside by the surface shells of two superimposed, concentric cylinders. The upper part 6 has a smaller diameter than the lower part 7, which is offset from the upper part 6 by means of a shoulder 8. A borehole 9, which intersperses the whole length of the socket 1, serves to accommodate the lamp 2. Two diametrically opposite longitudinal slots 10, which are parallel to the axis are provided in the upper part 6 of the socket 1. These slots 10 continue in the lower part 7 of the socket 1 by an amount 12, which corresponds approximately to the thickness 11 of the connecting leads 5 of the lamp. The width 13 of these slots 10 corresponds approximately to the diameter 11 of the connecting leads 5 of the lamp.
Two further slots 14, which are offset by 90° relative to the slots 10, are present. In the embodiments reproduced, these slots 14 intersperse the narrower cylindrical part 6 over the whole of its height and the wider cylindrical part 7 over about two thirds of its height. A spring 15 is integrally molded parallel to the longitudinal axis of the socket 1 at the bottom of each slot 14. The spring 15 is radially outside of the surface shell of the cylinder 6 of lesser external diameter and is radially movable within the slot 14 because of the low radial cross section of the shaft of spring 15. At the upper end of the spring 15, there is a catch head 16, which protrudes to the outside relative to the spring 15. The catch head 16 is divided into an upper side 17 and an underside 18 by an edge running transversely to the longitudinal axis of the socket 1. The upper side 17 is inclined slightly relative to the surface shell of the spring 15. The underside 18 runs at an acute angle to the plane of the printed circuit board 19 at an average distance 20 from the shoulder 8 of the broader cylindrical part 7, which corresponds to the thickness 21 of the printed circuit board 19.
FIG. 5 shows a printed board 19 for accommodating this embodiment of socket 1. The printed circuit board 19 has an essentially circular recess 22, the diameter of which is at least equal to the diameter of the narrower socket part 6. Two rectangular depressions 23, disposed diametrically opposite one another at the circumference, correspond in their cross section and in their position to the shafts of the springs 15. The contact surfaces 24 consist of sectors with an opening angle of about 20°, which extend outwards up to a concentric circle with approximately the diameter of the wider socket part 7.
For insertion in the socket 1, the lamp 2 with the connecting leads 5 bent as shown in FIG. 1, is rotated about its longitudinal axis, until each connecting lead 5 engages a slot 10. The lamp 2 is now pushed from above into the socket 1, until the bent lamp connecting leads 5 lie on the bottom of the slot 10 in the wider part 7. Because of the slots 10, the socket 1 is radially flexible in the region of the narrower part 6, so that the glass bulb 3 can be held by means of a press fit and removed again at any time, for example, when it is burnt out. If the arrangement is exposed to high mechanical stresses, as is the case in motor vehicles, the glass bulb 3 can be fixed additionally with adhesive at the inside of the borehole 9.
The combination of socket 1 and lamp 2 is inserted with the glass bulb first from the underside 25 of the printed circuit board 19. In so doing, the combination is to be twisted about its longitudinal axis, so that the springs 15 are in alignment with the lateral recesses 23 of the printed circuit board opening 22. Since the spring heads 16 protrude outwards, they are resilient radially inwards in the slot 14 when pressed through the recesses 23 and finally again outwards on the upper side 26 of the printed circuit board 19.
When the socket 1 is inserted in the opening 22 of the printed circuit board, a twisting of the socket 1 relative to the printed circuit board 19 is prevented by the arrangement of the springs 15 outside of the surface shell of the cylindrical part 6 of lesser external diameter.
FIGS. 6, 7 and 8 show a different embodiment of the inventive socket. Unlike the previously described socket, the place of the springs is taken here by two diametrically opposite clamping heads 27, which are disposed at the cylindrical part 6 of lesser diameter at an angle other than 90° with the slots 10 and the distance 28 of which from the shoulder 8 of the cylindrical part 7 of larger diameter corresponds to the thickness 21 of the printed circuit board 19. At that end of the clamping heads 27, which is furthest removed from the next slot 10, these clamping heads 27 are constructed as cross members 29 of lesser diameter parallel to the axis over the whole length of the cylinder 6. Two notches 30, the width 31 and minimum depth 32 of which correspond to the diameter 11 of the connecting leads 5 of the lamp, extend diametrically over the whole height of the cylindrical part 7 of larger diameter and are connected with the slots 10 which have a depth 32.
FIG. 9 shows the associated printed circuit board 19 with the opening 33. The inner concentric circle, which bounds the opening 33, has at least the same diameter as the narrower part 6 of the socket 1. Two depressions 34, congruent with the clamping heads 27, are disposed diametrically opposite one another at the opening 33. The whole of the periphery between the depressions 34 serves as contact surface 35, which extends outwards in two halves up to a concentric circle of about the diameter of the wider socket part 7.
Since the wires 5 are bent by more than 90° before the lamp 2 is inserted in the socket 1, they protrude at an angle from the bottom of the slot 10 after the insertion. To protect the ends of the connecting leads 5 of the lamp, they are offset towards the wider part 7 of the socket 1 and pressed into the notches 30. At the same time, the connecting leads 5 of the lamp still protrude in the region of the shoulder 8 by a certain amount 36 from the slots 10.
The socket 1 is introduced into an opening 33 in the printed circuit board from the direction of the contacting side 25. In so doing, the clamping heads 27 are set in position against the recesses 34 in the opening 33 of the printed circuit board. If the socket 1 has been pushed in so far, that the bent connecting leads 5 of the lamp are pressed against the underside 25 of the printed circuit board, the clamping heads 27 are above the printed circuit board 19 and the socket 1 can be locked by twisting 37. The cross members 29 see to it that there is a defined direction of rotation 37 for the attachment and, at the same time, limit the angle of rotation.
In the case of this embodiment, the socket 1 assumes the task of a positive connection with the printed circuit board 19. Because of the projection 36, the connecting leads 5 of the lamp produce the contacting pressure required for establishing electrical contact with the printed circuit board 19. Additionally, the frictional forces between the printed circuit board 19 and the clamping heads 27 are increased by these means. This prevents the sockets 1 being twisted unintentionally out of the opening 33 of the printed circuit board.
The socket 1, which is shown in FIGS. 10, 11 and 12, combines the advantageous characteristics of embodiments 1 and 2. Unlike embodiment 1, socket part 7 of larger diameter is made wider and provided with two diametrically opposite notches 30 over its whole height. In the region of the shoulder 8, these notches go over into the slots 10. Their width 31 and minimum depth 32 correspond to the diameter 11 of the connecting leads 5 of the lamp.
The associated printed circuit board corresponds basically to that shown in FIG. 5. Because of the larger diameter of part 7, the contact areas 24 extend further towards the outside.
The lamp 2 is inserted in the socket 1 in the same way as in the case of embodiment 2; the socket 1 is inserted in an opening 22 of the printed circuit board in the same way as in the case of embodiment 1. The connecting leads 5 of the lamp, which protrude from the slots 10 by an amount 36, increase the contacting pressure and expand the tolerance range of the thickness of the printed circuit board 19, in which reliable contact between the leads 5 and the contact surfaces 24 is ensured.
The embodiments of FIGS. 2 to 4 and 10 to 12 additionally have the advantage, that they can be mounted automatically in the printed circuit board. For this purpose, the lamps can be supplied either on a pallet lined up on a plastic belt or on a stick ("curtain rod") appropriate for a gripping device of an automatic assembly machine. Moreover, the embodiment of FIGS. 2 also has the advantage that it can be soldered by wave soldering, since the glass envelope is protected by the plastic part during the soldering process (tension stesses would result if there were direct contact between the hot soldering tin and the glass bulb). Accordingly, on passing through a wave soldering installation, the projecting electrodes 5 can be soldered automtically. Up to now lamps could only be soldered manually in applications, which required a low overall height from the upper side of the printed circuit board up to the top of the glass bulb.
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A socket for a miniature incandescent lamp for the detachable and lockable insertion in a recess in a printed circuit board and for making electrical contact with the lamp by pressing the connecting leads against the printed circuit board with a separate manufacture of the socket and the lamp, the socket consisting of a hollow cylinder with two axially superimposed parts of different external diameters, the cylinder, to accommodate the connecting leads of the lamp, having two diametrically opposite longitudinal slots, the width of which corresponds approximately to the diameter of the connecting leads and which extend over the whole height of the part of smaller diameter and into the part of larger diameter by an amount corresponding at most to the diameter of the connecting leads.
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RELATED APPLICATIONS
[0001] This application corresponds to PCT/EP2009/008422, filed Nov. 26, 2009, which claims the benefit of German Application No. 10 2008 060 305.8, filed Dec. 3, 2008, the subject matter of which is incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] The invention relates to an airbag.
[0003] At present airbags are preferably made of a polyamide fabric, wherein as yarn for the fabric frequently PA66 (nylon) is made use of.
[0004] Efforts are made to replace the nylon yarn with a polyester yarn, because the manufacture of the latter is less complicated and less expensive, as described in U.S. Pat. No. 7,375,042, for instance.
SUMMARY OF THE INVENTION
[0005] It is the object of the invention to provide an airbag which includes a fabric with a polyester yarn while at the same time maintaining the positive characteristics of an airbag having a fabric consisting of nylon.
[0006] This is achieved by an airbag having a fabric which includes a polyester yarn the elongation at break of which is approximately 20% to 30%, especially approx. 24% to 25%, and the shrinkage of which is less than approximately 1%, especially less than 0.5%. Exactly the characteristics of the yarn largely determine the characteristics of the fabric. In order to be suited for use in an airbag, the yarn has to have, while exhibiting sufficient strength or breaking strength, an as high elongation as possible and simultaneously has to excel by an as low shrinkage as possible in heat and/or moisture. It is ensured with said parameters that the technical requirements made to an airbag can be met.
[0007] It is possible to manufacture the fabric of the airbag completely of such yarn.
[0008] The viscosity of a yarn in general is inversely proportional to the elongation at break thereof so that yarns having a high viscosity have less elongation and vice versa. The viscosity of the polyester yarn used in the invention preferably ranges between 65 cN/tex and 75 cN/tex, especially approximately between 70 cN/tex and 71 cN/tex.
[0009] The breaking strength of the polyester yarn preferably amounts to 30% to 40%, especially to approximately 33% to 34%.
[0010] In the case of airbags of polyamide yarn the cover factor of the fabric advantageously ranges approximately between 1800 and 2000. The cover factor is calculated from the thread size d in deniers and the thread density wc and fc of the warps and wefts per inch (cover factor=√d*wc+√d*fc).
[0011] Polyester has a higher specific density (1.38 compared to 1.14) and thus a lower volume than nylon. In order to obtain an equivalent cover factor using a polyester yarn, the higher specific density has to be taken into account and compensated for by a larger thread size. A fabric made of a nylon thread having a thread size of 347 deniers in a composite fabric of 50 respective warps and wefts per inch has a cover factor of 1863, for instance. In order to obtain a corresponding fabric with a polyester yarn, the thread size must be adapted in accordance with the different specific densities so that in the case of the invention preferably a thread size of 420 deniers is resulting for a polyester yarn which as to volume is equivalent to a nylon yarn of 347 deniers.
[0012] Preferably, the thread size of the polyester yarn approximately is between 400 and 450 deniers.
[0013] The polyester yarn preferably had an ITC factor of more than approximately 1%, with ITC being abbreviated for Instantaneous Thermal Creep. This was measured at 100° C. The ITC value was determined analogously to the method given in U.S. Pat. No. 7,375,042.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Further features and advantages of the invention are resulting from the following description of an embodiment in combination with the enclosed drawings, in which
[0015] FIG. 1 schematically shows an airbag according to the invention;
[0016] FIG. 2 shows a diagram illustrating the adhesion of a coating on different fabrics, including a fabric of an airbag according to the invention; and
[0017] FIG. 3 shows pressure curves for two airbags according to the invention.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0018] FIG. 1 shows an airbag 10 in the form of a conventional curtain-shaped side airbag. But the airbag 10 could as well be of any other type, such as a driver-side or passenger-side airbag, a side airbag deploying from the backrest or a knee airbag.
[0019] The airbag 10 consists of a fabric made of polyester yarn having a filament figure of 96, breaking strength of 33.5 N, viscosity of 70.6 cN/tex, elongation at break of 24.4% and shrinkage of 0.3%. The shrinkage was measured according to the ASTM D 4974 method in which a relaxed thread sample is subjected to dry heat at a predetermined tension for a predetermined period of time. In said example the load is 0.05 cN/dtex at a temperature of 177° C. for a period of time of 10 minutes. The mean value established for the magnitude of the ITC was 1.5% (having a standard deviation of 21%).
[0020] From this yarn a fabric having a yarn density of 19.5×19.5 warps and wefts per cm was manufactured. Said fabric exhibited a breaking strength of 3030 N in the warp direction and 3186 N in the weft direction while having an elongation at break of 31% in both directions. The total weight of the fabric was 195 g/m 2 . Further data for said fabric can be inferred from table 1 in which also a conventional airbag fabric made of 470 dtex PA66 yarn is listed for the purpose of comparison.
[0000]
TABLE 1
470dtex
TEST
UNIT
DIRECTION
470dtexPA66
PES
TOTAL WEIGHT
g/m 2
172
195
CONSTRUC-
warp
warp
171
196
TIONAL
threads/dm
DENSITY
weft
weft
173
199
threads/dm
THICKNESS
mm
0.30
0.24
VISCOSITY
N
warp
2978
3030
Weft
2943
3186
ELONGATION
%
warp
20.0
31.0
weft
25.0
31.0
INFLAM -
mm/min
warp
1
2
MABILITY
weft
1
2
COMB DRAWING
N
warp
164
373
FORCE
weft
175
342
RIGIDITY
N
warp
3.8
5.1
weft
3.8
5.4
TEAR
N
warp
194
135
PROPAGATION
weft
213
142
FORCE
[0021] The fabric was fabricated by the water jet method and was subsequently provided with a silicone coating of 25 g/m 2 (Bluestar TCS 7534). The fabric was used right from the loom without any further pre-treatments. Further data concerning this text compared to the equally coated conventional fabric of 470 dtex PA66 yarn are illustrated in Table 2.
[0000]
TABLE 2
CSS
Coating
470dtex
470dtex
TEST
ISO/ASTM
Unit
Direction
Min
Max
PA66
PES
TOTAL WEIGHT
ISO3801
g/m 2
NA
195
225
210
212
STRUCTURAL
ISO 7211-2
per dm
warp
172
188
178
196
DENSITY
per dm
weft
167
183
178
190
THICKNESS
ISO 5084
mm
NA
0.25
0.35
0.28
0.24
MAXIMUM
ASTMD5035
N
warp
2500
na
3363
3082
TENSILE
N
weft
2500
na
3297
3174
FORCE (50 MM
RAVEL STRIP
TENSILE)
ELONGATION
ASTMD5035
%
warp
25
45
31.3
30.1
%
weft
25
45
31.0
29.7
INFLAMMABILITY
ISO 3795
mm/min
warp
na
100
2
2
mm/min
weft
ra
100
2
2
COMB
ASTMD6479
N
warp
250
366
513
DRAWING
N
weft
250
369
430
FORCE
FLEXURAL
ASTMD4032
N
NA
6.0
5.7
8.1
STRENGTH
TEAR
ISO 13937-2
N
warp
175
285
289
PROPAGATION
N
weft
175
276
263
FORCE
FRICTION
ISO 8295
N/M
warp
0.4
0.24
0.23
COEFFICIENT -
N/N
weft
0.4
0.20
0.17
STATIC
ABRASION
ISO 5981
Strokes
warp
500
2000
2000
RESISTANCE
Strokes
weft
500
2000
2000
[0022] For the airbag fabric of polyester yarn a constantly high adhesive force for the coating is resulting both directly after application of the coating and after heat aging for 408 hours at 105° C. or moisture aging for 408 hours at 40° C. and a relative humidity of 95% (cf. FIG. 2 ).
[0023] Two side airbags made of said polyester yarn and woven in one piece which were provided with a PVC/polyurethane coating of 75 g/m 2 , with an initial filling pressure of more than 965 hPa (14 psi) after 5 s still exhibited an internal pressure of more than 689 hPa (10 psi). In this case a fabric density of 22 warp threads to 19.5 weft threads per cm was used for each layer. In FIG. 2 a filling test is illustrated with two airbags according to the invention manufactured with identical parameters. In general, a pressure of 50% of the maximum pressure after 5 s is considered to be sufficient for a roll-over protection.
[0024] It is also an advantage of the low shrinkage rate of the yarn that the width of the fabric panel can be better exploited, which has a positive effect on the arrangement of the airbag cuts. For instance, with the present water-jet weaving technology a maximum reed width of 230 cm can be obtained. When using a typical nylon yarn a maximum usable fabric width of approximately 200 cm is resulting therefrom. With the polyester yarn having low shrinkage used for this purpose a usable width of 210 cm can be expected with the same machine. A similar result is obtained when using a jacquard weaving machine for airbags woven in one piece. Said weaving machines usually function according to the Rapier method or by air-jets. Typically they have a maximum reed width of 280 cm, which results in a maximum usable fabric width of approximately 245 cm when making use of a conventional nylon thread. Thus a maximum airbag height of approximately 600 mm is permitted with a cut arrangement in four rows. The polyester yarn employed here, however, allows obtaining an airbag height of 625 mm. When arranging the cuts in five rows respective airbag heights of 500 mm can be obtained.
[0025] When making use of the afore described advantages, in the case of coated fabrics for airbags high-shrinking yarns can be dispensed with, because the gas permeability is reduced or prevented by the coating. But also with uncoated fabrics an impermeability to gas sufficient for a variety of applications can be reached by such polyester yarn.
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An airbag has a fabric including a polyester yarn having an elongation at break of approximately 20 to 30%, especially approximately 24 to 25%, and having a shrinkage that is less than approximately 1%, especially less than 0.5%.
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